drivers/spi/spi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 // SPI init/core code
   3 //
   4 // Copyright (C) 2005 David Brownell
   5 // Copyright (C) 2008 Secret Lab Technologies Ltd.
   6
   7 #include <linux/kernel.h>
   8 #include <linux/device.h>
   9 #include <linux/init.h>
  10 #include <linux/cache.h>
  11 #include <linux/dma-mapping.h>
  12 #include <linux/dmaengine.h>
  13 #include <linux/mutex.h>
  14 #include <linux/of_device.h>
  15 #include <linux/of_irq.h>
  16 #include <linux/clk/clk-conf.h>
  17 #include <linux/slab.h>
  18 #include <linux/mod_devicetable.h>
  19 #include <linux/spi/spi.h>
  20 #include <linux/spi/spi-mem.h>
  21 #include <linux/of_gpio.h>
  22 #include <linux/gpio/consumer.h>
  23 #include <linux/pm_runtime.h>
  24 #include <linux/pm_domain.h>
  25 #include <linux/property.h>
  26 #include <linux/export.h>
  27 #include <linux/sched/rt.h>
  28 #include <uapi/linux/sched/types.h>
  29 #include <linux/delay.h>
  30 #include <linux/kthread.h>
  31 #include <linux/ioport.h>
  32 #include <linux/acpi.h>
  33 #include <linux/highmem.h>
  34 #include <linux/idr.h>
  35 #include <linux/platform_data/x86/apple.h>
  36
  37 #define CREATE_TRACE_POINTS
  38 #include <trace/events/spi.h>
  39 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start);
  40 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop);
  41
  42 #include "internals.h"
  43
  44 static DEFINE_IDR(spi_master_idr);
  45
  46 static void spidev_release(struct device *dev)
  47 {
  48         struct spi_device       *spi = to_spi_device(dev);
  49
  50         spi_controller_put(spi->controller);
  51         kfree(spi->driver_override);
  52         kfree(spi);
  53 }
  54
  55 static ssize_t
  56 modalias_show(struct device *dev, struct device_attribute *a, char *buf)
  57 {
  58         const struct spi_device *spi = to_spi_device(dev);
  59         int len;
  60
  61         len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
  62         if (len != -ENODEV)
  63                 return len;
  64
  65         return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
  66 }
  67 static DEVICE_ATTR_RO(modalias);
  68
  69 static ssize_t driver_override_store(struct device *dev,
  70                                      struct device_attribute *a,
  71                                      const char *buf, size_t count)
  72 {
  73         struct spi_device *spi = to_spi_device(dev);
  74         const char *end = memchr(buf, '\n', count);
  75         const size_t len = end ? end - buf : count;
  76         const char *driver_override, *old;
  77
  78         /* We need to keep extra room for a newline when displaying value */
  79         if (len >= (PAGE_SIZE - 1))
  80                 return -EINVAL;
  81
  82         driver_override = kstrndup(buf, len, GFP_KERNEL);
  83         if (!driver_override)
  84                 return -ENOMEM;
  85
  86         device_lock(dev);
  87         old = spi->driver_override;
  88         if (len) {
  89                 spi->driver_override = driver_override;
  90         } else {
  91                 /* Empty string, disable driver override */
  92                 spi->driver_override = NULL;
  93                 kfree(driver_override);
  94         }
  95         device_unlock(dev);
  96         kfree(old);
  97
  98         return count;
  99 }
 100
 101 static ssize_t driver_override_show(struct device *dev,
 102                                     struct device_attribute *a, char *buf)
 103 {
 104         const struct spi_device *spi = to_spi_device(dev);
 105         ssize_t len;
 106
 107         device_lock(dev);
 108         len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
 109         device_unlock(dev);
 110         return len;
 111 }
 112 static DEVICE_ATTR_RW(driver_override);
 113
 114 #define SPI_STATISTICS_ATTRS(field, file)                               \
 115 static ssize_t spi_controller_##field##_show(struct device *dev,        \
 116                                              struct device_attribute *attr, \
 117                                              char *buf)                 \
 118 {                                                                       \
 119         struct spi_controller *ctlr = container_of(dev,                 \
 120                                          struct spi_controller, dev);   \
 121         return spi_statistics_##field##_show(&ctlr->statistics, buf);   \
 122 }                                                                       \
 123 static struct device_attribute dev_attr_spi_controller_##field = {      \
 124         .attr = { .name = file, .mode = 0444 },                         \
 125         .show = spi_controller_##field##_show,                          \
 126 };                                                                      \
 127 static ssize_t spi_device_##field##_show(struct device *dev,            \
 128                                          struct device_attribute *attr, \
 129                                         char *buf)                      \
 130 {                                                                       \
 131         struct spi_device *spi = to_spi_device(dev);                    \
 132         return spi_statistics_##field##_show(&spi->statistics, buf);    \
 133 }                                                                       \
 134 static struct device_attribute dev_attr_spi_device_##field = {          \
 135         .attr = { .name = file, .mode = 0444 },                         \
 136         .show = spi_device_##field##_show,                              \
 137 }
 138
 139 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string)      \
 140 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
 141                                             char *buf)                  \
 142 {                                                                       \
 143         unsigned long flags;                                            \
 144         ssize_t len;                                                    \
 145         spin_lock_irqsave(&stat->lock, flags);                          \
 146         len = sprintf(buf, format_string, stat->field);                 \
 147         spin_unlock_irqrestore(&stat->lock, flags);                     \
 148         return len;                                                     \
 149 }                                                                       \
 150 SPI_STATISTICS_ATTRS(name, file)
 151
 152 #define SPI_STATISTICS_SHOW(field, format_string)                       \
 153         SPI_STATISTICS_SHOW_NAME(field, __stringify(field),             \
 154                                  field, format_string)
 155
 156 SPI_STATISTICS_SHOW(messages, "%lu");
 157 SPI_STATISTICS_SHOW(transfers, "%lu");
 158 SPI_STATISTICS_SHOW(errors, "%lu");
 159 SPI_STATISTICS_SHOW(timedout, "%lu");
 160
 161 SPI_STATISTICS_SHOW(spi_sync, "%lu");
 162 SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
 163 SPI_STATISTICS_SHOW(spi_async, "%lu");
 164
 165 SPI_STATISTICS_SHOW(bytes, "%llu");
 166 SPI_STATISTICS_SHOW(bytes_rx, "%llu");
 167 SPI_STATISTICS_SHOW(bytes_tx, "%llu");
 168
 169 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number)              \
 170         SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index,           \
 171                                  "transfer_bytes_histo_" number,        \
 172                                  transfer_bytes_histo[index],  "%lu")
 173 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0,  "0-1");
 174 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1,  "2-3");
 175 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2,  "4-7");
 176 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3,  "8-15");
 177 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4,  "16-31");
 178 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5,  "32-63");
 179 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6,  "64-127");
 180 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7,  "128-255");
 181 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8,  "256-511");
 182 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9,  "512-1023");
 183 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
 184 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
 185 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
 186 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
 187 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
 188 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
 189 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
 190
 191 SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
 192
 193 static struct attribute *spi_dev_attrs[] = {
 194         &dev_attr_modalias.attr,
 195         &dev_attr_driver_override.attr,
 196         NULL,
 197 };
 198
 199 static const struct attribute_group spi_dev_group = {
 200         .attrs  = spi_dev_attrs,
 201 };
 202
 203 static struct attribute *spi_device_statistics_attrs[] = {
 204         &dev_attr_spi_device_messages.attr,
 205         &dev_attr_spi_device_transfers.attr,
 206         &dev_attr_spi_device_errors.attr,
 207         &dev_attr_spi_device_timedout.attr,
 208         &dev_attr_spi_device_spi_sync.attr,
 209         &dev_attr_spi_device_spi_sync_immediate.attr,
 210         &dev_attr_spi_device_spi_async.attr,
 211         &dev_attr_spi_device_bytes.attr,
 212         &dev_attr_spi_device_bytes_rx.attr,
 213         &dev_attr_spi_device_bytes_tx.attr,
 214         &dev_attr_spi_device_transfer_bytes_histo0.attr,
 215         &dev_attr_spi_device_transfer_bytes_histo1.attr,
 216         &dev_attr_spi_device_transfer_bytes_histo2.attr,
 217         &dev_attr_spi_device_transfer_bytes_histo3.attr,
 218         &dev_attr_spi_device_transfer_bytes_histo4.attr,
 219         &dev_attr_spi_device_transfer_bytes_histo5.attr,
 220         &dev_attr_spi_device_transfer_bytes_histo6.attr,
 221         &dev_attr_spi_device_transfer_bytes_histo7.attr,
 222         &dev_attr_spi_device_transfer_bytes_histo8.attr,
 223         &dev_attr_spi_device_transfer_bytes_histo9.attr,
 224         &dev_attr_spi_device_transfer_bytes_histo10.attr,
 225         &dev_attr_spi_device_transfer_bytes_histo11.attr,
 226         &dev_attr_spi_device_transfer_bytes_histo12.attr,
 227         &dev_attr_spi_device_transfer_bytes_histo13.attr,
 228         &dev_attr_spi_device_transfer_bytes_histo14.attr,
 229         &dev_attr_spi_device_transfer_bytes_histo15.attr,
 230         &dev_attr_spi_device_transfer_bytes_histo16.attr,
 231         &dev_attr_spi_device_transfers_split_maxsize.attr,
 232         NULL,
 233 };
 234
 235 static const struct attribute_group spi_device_statistics_group = {
 236         .name  = "statistics",
 237         .attrs  = spi_device_statistics_attrs,
 238 };
 239
 240 static const struct attribute_group *spi_dev_groups[] = {
 241         &spi_dev_group,
 242         &spi_device_statistics_group,
 243         NULL,
 244 };
 245
 246 static struct attribute *spi_controller_statistics_attrs[] = {
 247         &dev_attr_spi_controller_messages.attr,
 248         &dev_attr_spi_controller_transfers.attr,
 249         &dev_attr_spi_controller_errors.attr,
 250         &dev_attr_spi_controller_timedout.attr,
 251         &dev_attr_spi_controller_spi_sync.attr,
 252         &dev_attr_spi_controller_spi_sync_immediate.attr,
 253         &dev_attr_spi_controller_spi_async.attr,
 254         &dev_attr_spi_controller_bytes.attr,
 255         &dev_attr_spi_controller_bytes_rx.attr,
 256         &dev_attr_spi_controller_bytes_tx.attr,
 257         &dev_attr_spi_controller_transfer_bytes_histo0.attr,
 258         &dev_attr_spi_controller_transfer_bytes_histo1.attr,
 259         &dev_attr_spi_controller_transfer_bytes_histo2.attr,
 260         &dev_attr_spi_controller_transfer_bytes_histo3.attr,
 261         &dev_attr_spi_controller_transfer_bytes_histo4.attr,
 262         &dev_attr_spi_controller_transfer_bytes_histo5.attr,
 263         &dev_attr_spi_controller_transfer_bytes_histo6.attr,
 264         &dev_attr_spi_controller_transfer_bytes_histo7.attr,
 265         &dev_attr_spi_controller_transfer_bytes_histo8.attr,
 266         &dev_attr_spi_controller_transfer_bytes_histo9.attr,
 267         &dev_attr_spi_controller_transfer_bytes_histo10.attr,
 268         &dev_attr_spi_controller_transfer_bytes_histo11.attr,
 269         &dev_attr_spi_controller_transfer_bytes_histo12.attr,
 270         &dev_attr_spi_controller_transfer_bytes_histo13.attr,
 271         &dev_attr_spi_controller_transfer_bytes_histo14.attr,
 272         &dev_attr_spi_controller_transfer_bytes_histo15.attr,
 273         &dev_attr_spi_controller_transfer_bytes_histo16.attr,
 274         &dev_attr_spi_controller_transfers_split_maxsize.attr,
 275         NULL,
 276 };
 277
 278 static const struct attribute_group spi_controller_statistics_group = {
 279         .name  = "statistics",
 280         .attrs  = spi_controller_statistics_attrs,
 281 };
 282
 283 static const struct attribute_group *spi_master_groups[] = {
 284         &spi_controller_statistics_group,
 285         NULL,
 286 };
 287
 288 void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
 289                                        struct spi_transfer *xfer,
 290                                        struct spi_controller *ctlr)
 291 {
 292         unsigned long flags;
 293         int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
 294
 295         if (l2len < 0)
 296                 l2len = 0;
 297
 298         spin_lock_irqsave(&stats->lock, flags);
 299
 300         stats->transfers++;
 301         stats->transfer_bytes_histo[l2len]++;
 302
 303         stats->bytes += xfer->len;
 304         if ((xfer->tx_buf) &&
 305             (xfer->tx_buf != ctlr->dummy_tx))
 306                 stats->bytes_tx += xfer->len;
 307         if ((xfer->rx_buf) &&
 308             (xfer->rx_buf != ctlr->dummy_rx))
 309                 stats->bytes_rx += xfer->len;
 310
 311         spin_unlock_irqrestore(&stats->lock, flags);
 312 }
 313 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
 314
 315 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
 316  * and the sysfs version makes coldplug work too.
 317  */
 318
 319 static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
 320                                                 const struct spi_device *sdev)
 321 {
 322         while (id->name[0]) {
 323                 if (!strcmp(sdev->modalias, id->name))
 324                         return id;
 325                 id++;
 326         }
 327         return NULL;
 328 }
 329
 330 const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
 331 {
 332         const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
 333
 334         return spi_match_id(sdrv->id_table, sdev);
 335 }
 336 EXPORT_SYMBOL_GPL(spi_get_device_id);
 337
 338 static int spi_match_device(struct device *dev, struct device_driver *drv)
 339 {
 340         const struct spi_device *spi = to_spi_device(dev);
 341         const struct spi_driver *sdrv = to_spi_driver(drv);
 342
 343         /* Check override first, and if set, only use the named driver */
 344         if (spi->driver_override)
 345                 return strcmp(spi->driver_override, drv->name) == 0;
 346
 347         /* Attempt an OF style match */
 348         if (of_driver_match_device(dev, drv))
 349                 return 1;
 350
 351         /* Then try ACPI */
 352         if (acpi_driver_match_device(dev, drv))
 353                 return 1;
 354
 355         if (sdrv->id_table)
 356                 return !!spi_match_id(sdrv->id_table, spi);
 357
 358         return strcmp(spi->modalias, drv->name) == 0;
 359 }
 360
 361 static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
 362 {
 363         const struct spi_device         *spi = to_spi_device(dev);
 364         int rc;
 365
 366         rc = acpi_device_uevent_modalias(dev, env);
 367         if (rc != -ENODEV)
 368                 return rc;
 369
 370         return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
 371 }
 372
 373 static int spi_probe(struct device *dev)
 374 {
 375         const struct spi_driver         *sdrv = to_spi_driver(dev->driver);
 376         struct spi_device               *spi = to_spi_device(dev);
 377         int ret;
 378
 379         ret = of_clk_set_defaults(dev->of_node, false);
 380         if (ret)
 381                 return ret;
 382
 383         if (dev->of_node) {
 384                 spi->irq = of_irq_get(dev->of_node, 0);
 385                 if (spi->irq == -EPROBE_DEFER)
 386                         return -EPROBE_DEFER;
 387                 if (spi->irq < 0)
 388                         spi->irq = 0;
 389         }
 390
 391         ret = dev_pm_domain_attach(dev, true);
 392         if (ret)
 393                 return ret;
 394
 395         if (sdrv->probe) {
 396                 ret = sdrv->probe(spi);
 397                 if (ret)
 398                         dev_pm_domain_detach(dev, true);
 399         }
 400
 401         return ret;
 402 }
 403
 404 static void spi_remove(struct device *dev)
 405 {
 406         const struct spi_driver         *sdrv = to_spi_driver(dev->driver);
 407
 408         if (sdrv->remove) {
 409                 int ret;
 410
 411                 ret = sdrv->remove(to_spi_device(dev));
 412                 if (ret)
 413                         dev_warn(dev,
 414                                  "Failed to unbind driver (%pe), ignoring\n",
 415                                  ERR_PTR(ret));
 416         }
 417
 418         dev_pm_domain_detach(dev, true);
 419 }
 420
 421 static void spi_shutdown(struct device *dev)
 422 {
 423         if (dev->driver) {
 424                 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
 425
 426                 if (sdrv->shutdown)
 427                         sdrv->shutdown(to_spi_device(dev));
 428         }
 429 }
 430
 431 struct bus_type spi_bus_type = {
 432         .name           = "spi",
 433         .dev_groups     = spi_dev_groups,
 434         .match          = spi_match_device,
 435         .uevent         = spi_uevent,
 436         .probe          = spi_probe,
 437         .remove         = spi_remove,
 438         .shutdown       = spi_shutdown,
 439 };
 440 EXPORT_SYMBOL_GPL(spi_bus_type);
 441
 442 /**
 443  * __spi_register_driver - register a SPI driver
 444  * @owner: owner module of the driver to register
 445  * @sdrv: the driver to register
 446  * Context: can sleep
 447  *
 448  * Return: zero on success, else a negative error code.
 449  */
 450 int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
 451 {
 452         sdrv->driver.owner = owner;
 453         sdrv->driver.bus = &spi_bus_type;
 454         return driver_register(&sdrv->driver);
 455 }
 456 EXPORT_SYMBOL_GPL(__spi_register_driver);
 457
 458 /*-------------------------------------------------------------------------*/
 459
 460 /* SPI devices should normally not be created by SPI device drivers; that
 461  * would make them board-specific.  Similarly with SPI controller drivers.
 462  * Device registration normally goes into like arch/.../mach.../board-YYY.c
 463  * with other readonly (flashable) information about mainboard devices.
 464  */
 465
 466 struct boardinfo {
 467         struct list_head        list;
 468         struct spi_board_info   board_info;
 469 };
 470
 471 static LIST_HEAD(board_list);
 472 static LIST_HEAD(spi_controller_list);
 473
 474 /*
 475  * Used to protect add/del operation for board_info list and
 476  * spi_controller list, and their matching process
 477  * also used to protect object of type struct idr
 478  */
 479 static DEFINE_MUTEX(board_lock);
 480
 481 /**
 482  * spi_alloc_device - Allocate a new SPI device
 483  * @ctlr: Controller to which device is connected
 484  * Context: can sleep
 485  *
 486  * Allows a driver to allocate and initialize a spi_device without
 487  * registering it immediately.  This allows a driver to directly
 488  * fill the spi_device with device parameters before calling
 489  * spi_add_device() on it.
 490  *
 491  * Caller is responsible to call spi_add_device() on the returned
 492  * spi_device structure to add it to the SPI controller.  If the caller
 493  * needs to discard the spi_device without adding it, then it should
 494  * call spi_dev_put() on it.
 495  *
 496  * Return: a pointer to the new device, or NULL.
 497  */
 498 struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
 499 {
 500         struct spi_device       *spi;
 501
 502         if (!spi_controller_get(ctlr))
 503                 return NULL;
 504
 505         spi = kzalloc(sizeof(*spi), GFP_KERNEL);
 506         if (!spi) {
 507                 spi_controller_put(ctlr);
 508                 return NULL;
 509         }
 510
 511         spi->master = spi->controller = ctlr;
 512         spi->dev.parent = &ctlr->dev;
 513         spi->dev.bus = &spi_bus_type;
 514         spi->dev.release = spidev_release;
 515         spi->cs_gpio = -ENOENT;
 516         spi->mode = ctlr->buswidth_override_bits;
 517
 518         spin_lock_init(&spi->statistics.lock);
 519
 520         device_initialize(&spi->dev);
 521         return spi;
 522 }
 523 EXPORT_SYMBOL_GPL(spi_alloc_device);
 524
 525 static void spi_dev_set_name(struct spi_device *spi)
 526 {
 527         struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
 528
 529         if (adev) {
 530                 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
 531                 return;
 532         }
 533
 534         dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
 535                      spi->chip_select);
 536 }
 537
 538 static int spi_dev_check(struct device *dev, void *data)
 539 {
 540         struct spi_device *spi = to_spi_device(dev);
 541         struct spi_device *new_spi = data;
 542
 543         if (spi->controller == new_spi->controller &&
 544             spi->chip_select == new_spi->chip_select)
 545                 return -EBUSY;
 546         return 0;
 547 }
 548
 549 static void spi_cleanup(struct spi_device *spi)
 550 {
 551         if (spi->controller->cleanup)
 552                 spi->controller->cleanup(spi);
 553 }
 554
 555 static int __spi_add_device(struct spi_device *spi)
 556 {
 557         struct spi_controller *ctlr = spi->controller;
 558         struct device *dev = ctlr->dev.parent;
 559         int status;
 560
 561         status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
 562         if (status) {
 563                 dev_err(dev, "chipselect %d already in use\n",
 564                                 spi->chip_select);
 565                 return status;
 566         }
 567
 568         /* Controller may unregister concurrently */
 569         if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
 570             !device_is_registered(&ctlr->dev)) {
 571                 return -ENODEV;
 572         }
 573
 574         /* Descriptors take precedence */
 575         if (ctlr->cs_gpiods)
 576                 spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
 577         else if (ctlr->cs_gpios)
 578                 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
 579
 580         /* Drivers may modify this initial i/o setup, but will
 581          * normally rely on the device being setup.  Devices
 582          * using SPI_CS_HIGH can't coexist well otherwise...
 583          */
 584         status = spi_setup(spi);
 585         if (status < 0) {
 586                 dev_err(dev, "can't setup %s, status %d\n",
 587                                 dev_name(&spi->dev), status);
 588                 return status;
 589         }
 590
 591         /* Device may be bound to an active driver when this returns */
 592         status = device_add(&spi->dev);
 593         if (status < 0) {
 594                 dev_err(dev, "can't add %s, status %d\n",
 595                                 dev_name(&spi->dev), status);
 596                 spi_cleanup(spi);
 597         } else {
 598                 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
 599         }
 600
 601         return status;
 602 }
 603
 604 /**
 605  * spi_add_device - Add spi_device allocated with spi_alloc_device
 606  * @spi: spi_device to register
 607  *
 608  * Companion function to spi_alloc_device.  Devices allocated with
 609  * spi_alloc_device can be added onto the spi bus with this function.
 610  *
 611  * Return: 0 on success; negative errno on failure
 612  */
 613 int spi_add_device(struct spi_device *spi)
 614 {
 615         struct spi_controller *ctlr = spi->controller;
 616         struct device *dev = ctlr->dev.parent;
 617         int status;
 618
 619         /* Chipselects are numbered 0..max; validate. */
 620         if (spi->chip_select >= ctlr->num_chipselect) {
 621                 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
 622                         ctlr->num_chipselect);
 623                 return -EINVAL;
 624         }
 625
 626         /* Set the bus ID string */
 627         spi_dev_set_name(spi);
 628
 629         /* We need to make sure there's no other device with this
 630          * chipselect **BEFORE** we call setup(), else we'll trash
 631          * its configuration.  Lock against concurrent add() calls.
 632          */
 633         mutex_lock(&ctlr->add_lock);
 634         status = __spi_add_device(spi);
 635         mutex_unlock(&ctlr->add_lock);
 636         return status;
 637 }
 638 EXPORT_SYMBOL_GPL(spi_add_device);
 639
 640 static int spi_add_device_locked(struct spi_device *spi)
 641 {
 642         struct spi_controller *ctlr = spi->controller;
 643         struct device *dev = ctlr->dev.parent;
 644
 645         /* Chipselects are numbered 0..max; validate. */
 646         if (spi->chip_select >= ctlr->num_chipselect) {
 647                 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
 648                         ctlr->num_chipselect);
 649                 return -EINVAL;
 650         }
 651
 652         /* Set the bus ID string */
 653         spi_dev_set_name(spi);
 654
 655         WARN_ON(!mutex_is_locked(&ctlr->add_lock));
 656         return __spi_add_device(spi);
 657 }
 658
 659 /**
 660  * spi_new_device - instantiate one new SPI device
 661  * @ctlr: Controller to which device is connected
 662  * @chip: Describes the SPI device
 663  * Context: can sleep
 664  *
 665  * On typical mainboards, this is purely internal; and it's not needed
 666  * after board init creates the hard-wired devices.  Some development
 667  * platforms may not be able to use spi_register_board_info though, and
 668  * this is exported so that for example a USB or parport based adapter
 669  * driver could add devices (which it would learn about out-of-band).
 670  *
 671  * Return: the new device, or NULL.
 672  */
 673 struct spi_device *spi_new_device(struct spi_controller *ctlr,
 674                                   struct spi_board_info *chip)
 675 {
 676         struct spi_device       *proxy;
 677         int                     status;
 678
 679         /* NOTE:  caller did any chip->bus_num checks necessary.
 680          *
 681          * Also, unless we change the return value convention to use
 682          * error-or-pointer (not NULL-or-pointer), troubleshootability
 683          * suggests syslogged diagnostics are best here (ugh).
 684          */
 685
 686         proxy = spi_alloc_device(ctlr);
 687         if (!proxy)
 688                 return NULL;
 689
 690         WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
 691
 692         proxy->chip_select = chip->chip_select;
 693         proxy->max_speed_hz = chip->max_speed_hz;
 694         proxy->mode = chip->mode;
 695         proxy->irq = chip->irq;
 696         strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
 697         proxy->dev.platform_data = (void *) chip->platform_data;
 698         proxy->controller_data = chip->controller_data;
 699         proxy->controller_state = NULL;
 700
 701         if (chip->swnode) {
 702                 status = device_add_software_node(&proxy->dev, chip->swnode);
 703                 if (status) {
 704                         dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n",
 705                                 chip->modalias, status);
 706                         goto err_dev_put;
 707                 }
 708         }
 709
 710         status = spi_add_device(proxy);
 711         if (status < 0)
 712                 goto err_dev_put;
 713
 714         return proxy;
 715
 716 err_dev_put:
 717         device_remove_software_node(&proxy->dev);
 718         spi_dev_put(proxy);
 719         return NULL;
 720 }
 721 EXPORT_SYMBOL_GPL(spi_new_device);
 722
 723 /**
 724  * spi_unregister_device - unregister a single SPI device
 725  * @spi: spi_device to unregister
 726  *
 727  * Start making the passed SPI device vanish. Normally this would be handled
 728  * by spi_unregister_controller().
 729  */
 730 void spi_unregister_device(struct spi_device *spi)
 731 {
 732         if (!spi)
 733                 return;
 734
 735         if (spi->dev.of_node) {
 736                 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
 737                 of_node_put(spi->dev.of_node);
 738         }
 739         if (ACPI_COMPANION(&spi->dev))
 740                 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
 741         device_remove_software_node(&spi->dev);
 742         device_del(&spi->dev);
 743         spi_cleanup(spi);
 744         put_device(&spi->dev);
 745 }
 746 EXPORT_SYMBOL_GPL(spi_unregister_device);
 747
 748 static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
 749                                               struct spi_board_info *bi)
 750 {
 751         struct spi_device *dev;
 752
 753         if (ctlr->bus_num != bi->bus_num)
 754                 return;
 755
 756         dev = spi_new_device(ctlr, bi);
 757         if (!dev)
 758                 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
 759                         bi->modalias);
 760 }
 761
 762 /**
 763  * spi_register_board_info - register SPI devices for a given board
 764  * @info: array of chip descriptors
 765  * @n: how many descriptors are provided
 766  * Context: can sleep
 767  *
 768  * Board-specific early init code calls this (probably during arch_initcall)
 769  * with segments of the SPI device table.  Any device nodes are created later,
 770  * after the relevant parent SPI controller (bus_num) is defined.  We keep
 771  * this table of devices forever, so that reloading a controller driver will
 772  * not make Linux forget about these hard-wired devices.
 773  *
 774  * Other code can also call this, e.g. a particular add-on board might provide
 775  * SPI devices through its expansion connector, so code initializing that board
 776  * would naturally declare its SPI devices.
 777  *
 778  * The board info passed can safely be __initdata ... but be careful of
 779  * any embedded pointers (platform_data, etc), they're copied as-is.
 780  *
 781  * Return: zero on success, else a negative error code.
 782  */
 783 int spi_register_board_info(struct spi_board_info const *info, unsigned n)
 784 {
 785         struct boardinfo *bi;
 786         int i;
 787
 788         if (!n)
 789                 return 0;
 790
 791         bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
 792         if (!bi)
 793                 return -ENOMEM;
 794
 795         for (i = 0; i < n; i++, bi++, info++) {
 796                 struct spi_controller *ctlr;
 797
 798                 memcpy(&bi->board_info, info, sizeof(*info));
 799
 800                 mutex_lock(&board_lock);
 801                 list_add_tail(&bi->list, &board_list);
 802                 list_for_each_entry(ctlr, &spi_controller_list, list)
 803                         spi_match_controller_to_boardinfo(ctlr,
 804                                                           &bi->board_info);
 805                 mutex_unlock(&board_lock);
 806         }
 807
 808         return 0;
 809 }
 810
 811 /*-------------------------------------------------------------------------*/
 812
 813 static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
 814 {
 815         bool activate = enable;
 816
 817         /*
 818          * Avoid calling into the driver (or doing delays) if the chip select
 819          * isn't actually changing from the last time this was called.
 820          */
 821         if (!force && (spi->controller->last_cs_enable == enable) &&
 822             (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
 823                 return;
 824
 825         trace_spi_set_cs(spi, activate);
 826
 827         spi->controller->last_cs_enable = enable;
 828         spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
 829
 830         if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
 831             !spi->controller->set_cs_timing) {
 832                 if (activate)
 833                         spi_delay_exec(&spi->cs_setup, NULL);
 834                 else
 835                         spi_delay_exec(&spi->cs_hold, NULL);
 836         }
 837
 838         if (spi->mode & SPI_CS_HIGH)
 839                 enable = !enable;
 840
 841         if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
 842                 if (!(spi->mode & SPI_NO_CS)) {
 843                         if (spi->cs_gpiod) {
 844                                 /*
 845                                  * Historically ACPI has no means of the GPIO polarity and
 846                                  * thus the SPISerialBus() resource defines it on the per-chip
 847                                  * basis. In order to avoid a chain of negations, the GPIO
 848                                  * polarity is considered being Active High. Even for the cases
 849                                  * when _DSD() is involved (in the updated versions of ACPI)
 850                                  * the GPIO CS polarity must be defined Active High to avoid
 851                                  * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
 852                                  * into account.
 853                                  */
 854                                 if (has_acpi_companion(&spi->dev))
 855                                         gpiod_set_value_cansleep(spi->cs_gpiod, !enable);
 856                                 else
 857                                         /* Polarity handled by GPIO library */
 858                                         gpiod_set_value_cansleep(spi->cs_gpiod, activate);
 859                         } else {
 860                                 /*
 861                                  * invert the enable line, as active low is
 862                                  * default for SPI.
 863                                  */
 864                                 gpio_set_value_cansleep(spi->cs_gpio, !enable);
 865                         }
 866                 }
 867                 /* Some SPI masters need both GPIO CS & slave_select */
 868                 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
 869                     spi->controller->set_cs)
 870                         spi->controller->set_cs(spi, !enable);
 871         } else if (spi->controller->set_cs) {
 872                 spi->controller->set_cs(spi, !enable);
 873         }
 874
 875         if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
 876             !spi->controller->set_cs_timing) {
 877                 if (!activate)
 878                         spi_delay_exec(&spi->cs_inactive, NULL);
 879         }
 880 }
 881
 882 #ifdef CONFIG_HAS_DMA
 883 int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
 884                 struct sg_table *sgt, void *buf, size_t len,
 885                 enum dma_data_direction dir)
 886 {
 887         const bool vmalloced_buf = is_vmalloc_addr(buf);
 888         unsigned int max_seg_size = dma_get_max_seg_size(dev);
 889 #ifdef CONFIG_HIGHMEM
 890         const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
 891                                 (unsigned long)buf < (PKMAP_BASE +
 892                                         (LAST_PKMAP * PAGE_SIZE)));
 893 #else
 894         const bool kmap_buf = false;
 895 #endif
 896         int desc_len;
 897         int sgs;
 898         struct page *vm_page;
 899         struct scatterlist *sg;
 900         void *sg_buf;
 901         size_t min;
 902         int i, ret;
 903
 904         if (vmalloced_buf || kmap_buf) {
 905                 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
 906                 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
 907         } else if (virt_addr_valid(buf)) {
 908                 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
 909                 sgs = DIV_ROUND_UP(len, desc_len);
 910         } else {
 911                 return -EINVAL;
 912         }
 913
 914         ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
 915         if (ret != 0)
 916                 return ret;
 917
 918         sg = &sgt->sgl[0];
 919         for (i = 0; i < sgs; i++) {
 920
 921                 if (vmalloced_buf || kmap_buf) {
 922                         /*
 923                          * Next scatterlist entry size is the minimum between
 924                          * the desc_len and the remaining buffer length that
 925                          * fits in a page.
 926                          */
 927                         min = min_t(size_t, desc_len,
 928                                     min_t(size_t, len,
 929                                           PAGE_SIZE - offset_in_page(buf)));
 930                         if (vmalloced_buf)
 931                                 vm_page = vmalloc_to_page(buf);
 932                         else
 933                                 vm_page = kmap_to_page(buf);
 934                         if (!vm_page) {
 935                                 sg_free_table(sgt);
 936                                 return -ENOMEM;
 937                         }
 938                         sg_set_page(sg, vm_page,
 939                                     min, offset_in_page(buf));
 940                 } else {
 941                         min = min_t(size_t, len, desc_len);
 942                         sg_buf = buf;
 943                         sg_set_buf(sg, sg_buf, min);
 944                 }
 945
 946                 buf += min;
 947                 len -= min;
 948                 sg = sg_next(sg);
 949         }
 950
 951         ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
 952         if (!ret)
 953                 ret = -ENOMEM;
 954         if (ret < 0) {
 955                 sg_free_table(sgt);
 956                 return ret;
 957         }
 958
 959         sgt->nents = ret;
 960
 961         return 0;
 962 }
 963
 964 void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
 965                    struct sg_table *sgt, enum dma_data_direction dir)
 966 {
 967         if (sgt->orig_nents) {
 968                 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
 969                 sg_free_table(sgt);
 970         }
 971 }
 972
 973 static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
 974 {
 975         struct device *tx_dev, *rx_dev;
 976         struct spi_transfer *xfer;
 977         int ret;
 978
 979         if (!ctlr->can_dma)
 980                 return 0;
 981
 982         if (ctlr->dma_tx)
 983                 tx_dev = ctlr->dma_tx->device->dev;
 984         else if (ctlr->dma_map_dev)
 985                 tx_dev = ctlr->dma_map_dev;
 986         else
 987                 tx_dev = ctlr->dev.parent;
 988
 989         if (ctlr->dma_rx)
 990                 rx_dev = ctlr->dma_rx->device->dev;
 991         else if (ctlr->dma_map_dev)
 992                 rx_dev = ctlr->dma_map_dev;
 993         else
 994                 rx_dev = ctlr->dev.parent;
 995
 996         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
 997                 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
 998                         continue;
 999
1000                 if (xfer->tx_buf != NULL) {
1001                         ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
1002                                           (void *)xfer->tx_buf, xfer->len,
1003                                           DMA_TO_DEVICE);
1004                         if (ret != 0)
1005                                 return ret;
1006                 }
1007
1008                 if (xfer->rx_buf != NULL) {
1009                         ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
1010                                           xfer->rx_buf, xfer->len,
1011                                           DMA_FROM_DEVICE);
1012                         if (ret != 0) {
1013                                 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
1014                                               DMA_TO_DEVICE);
1015                                 return ret;
1016                         }
1017                 }
1018         }
1019
1020         ctlr->cur_msg_mapped = true;
1021
1022         return 0;
1023 }
1024
1025 static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
1026 {
1027         struct spi_transfer *xfer;
1028         struct device *tx_dev, *rx_dev;
1029
1030         if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
1031                 return 0;
1032
1033         if (ctlr->dma_tx)
1034                 tx_dev = ctlr->dma_tx->device->dev;
1035         else
1036                 tx_dev = ctlr->dev.parent;
1037
1038         if (ctlr->dma_rx)
1039                 rx_dev = ctlr->dma_rx->device->dev;
1040         else
1041                 rx_dev = ctlr->dev.parent;
1042
1043         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1044                 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1045                         continue;
1046
1047                 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1048                 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1049         }
1050
1051         ctlr->cur_msg_mapped = false;
1052
1053         return 0;
1054 }
1055 #else /* !CONFIG_HAS_DMA */
1056 static inline int __spi_map_msg(struct spi_controller *ctlr,
1057                                 struct spi_message *msg)
1058 {
1059         return 0;
1060 }
1061
1062 static inline int __spi_unmap_msg(struct spi_controller *ctlr,
1063                                   struct spi_message *msg)
1064 {
1065         return 0;
1066 }
1067 #endif /* !CONFIG_HAS_DMA */
1068
1069 static inline int spi_unmap_msg(struct spi_controller *ctlr,
1070                                 struct spi_message *msg)
1071 {
1072         struct spi_transfer *xfer;
1073
1074         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1075                 /*
1076                  * Restore the original value of tx_buf or rx_buf if they are
1077                  * NULL.
1078                  */
1079                 if (xfer->tx_buf == ctlr->dummy_tx)
1080                         xfer->tx_buf = NULL;
1081                 if (xfer->rx_buf == ctlr->dummy_rx)
1082                         xfer->rx_buf = NULL;
1083         }
1084
1085         return __spi_unmap_msg(ctlr, msg);
1086 }
1087
1088 static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1089 {
1090         struct spi_transfer *xfer;
1091         void *tmp;
1092         unsigned int max_tx, max_rx;
1093
1094         if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1095                 && !(msg->spi->mode & SPI_3WIRE)) {
1096                 max_tx = 0;
1097                 max_rx = 0;
1098
1099                 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1100                         if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1101                             !xfer->tx_buf)
1102                                 max_tx = max(xfer->len, max_tx);
1103                         if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1104                             !xfer->rx_buf)
1105                                 max_rx = max(xfer->len, max_rx);
1106                 }
1107
1108                 if (max_tx) {
1109                         tmp = krealloc(ctlr->dummy_tx, max_tx,
1110                                        GFP_KERNEL | GFP_DMA);
1111                         if (!tmp)
1112                                 return -ENOMEM;
1113                         ctlr->dummy_tx = tmp;
1114                         memset(tmp, 0, max_tx);
1115                 }
1116
1117                 if (max_rx) {
1118                         tmp = krealloc(ctlr->dummy_rx, max_rx,
1119                                        GFP_KERNEL | GFP_DMA);
1120                         if (!tmp)
1121                                 return -ENOMEM;
1122                         ctlr->dummy_rx = tmp;
1123                 }
1124
1125                 if (max_tx || max_rx) {
1126                         list_for_each_entry(xfer, &msg->transfers,
1127                                             transfer_list) {
1128                                 if (!xfer->len)
1129                                         continue;
1130                                 if (!xfer->tx_buf)
1131                                         xfer->tx_buf = ctlr->dummy_tx;
1132                                 if (!xfer->rx_buf)
1133                                         xfer->rx_buf = ctlr->dummy_rx;
1134                         }
1135                 }
1136         }
1137
1138         return __spi_map_msg(ctlr, msg);
1139 }
1140
1141 static int spi_transfer_wait(struct spi_controller *ctlr,
1142                              struct spi_message *msg,
1143                              struct spi_transfer *xfer)
1144 {
1145         struct spi_statistics *statm = &ctlr->statistics;
1146         struct spi_statistics *stats = &msg->spi->statistics;
1147         u32 speed_hz = xfer->speed_hz;
1148         unsigned long long ms;
1149
1150         if (spi_controller_is_slave(ctlr)) {
1151                 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1152                         dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1153                         return -EINTR;
1154                 }
1155         } else {
1156                 if (!speed_hz)
1157                         speed_hz = 100000;
1158
1159                 /*
1160                  * For each byte we wait for 8 cycles of the SPI clock.
1161                  * Since speed is defined in Hz and we want milliseconds,
1162                  * use respective multiplier, but before the division,
1163                  * otherwise we may get 0 for short transfers.
1164                  */
1165                 ms = 8LL * MSEC_PER_SEC * xfer->len;
1166                 do_div(ms, speed_hz);
1167
1168                 /*
1169                  * Increase it twice and add 200 ms tolerance, use
1170                  * predefined maximum in case of overflow.
1171                  */
1172                 ms += ms + 200;
1173                 if (ms > UINT_MAX)
1174                         ms = UINT_MAX;
1175
1176                 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1177                                                  msecs_to_jiffies(ms));
1178
1179                 if (ms == 0) {
1180                         SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1181                         SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1182                         dev_err(&msg->spi->dev,
1183                                 "SPI transfer timed out\n");
1184                         return -ETIMEDOUT;
1185                 }
1186         }
1187
1188         return 0;
1189 }
1190
1191 static void _spi_transfer_delay_ns(u32 ns)
1192 {
1193         if (!ns)
1194                 return;
1195         if (ns <= NSEC_PER_USEC) {
1196                 ndelay(ns);
1197         } else {
1198                 u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC);
1199
1200                 if (us <= 10)
1201                         udelay(us);
1202                 else
1203                         usleep_range(us, us + DIV_ROUND_UP(us, 10));
1204         }
1205 }
1206
1207 int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1208 {
1209         u32 delay = _delay->value;
1210         u32 unit = _delay->unit;
1211         u32 hz;
1212
1213         if (!delay)
1214                 return 0;
1215
1216         switch (unit) {
1217         case SPI_DELAY_UNIT_USECS:
1218                 delay *= NSEC_PER_USEC;
1219                 break;
1220         case SPI_DELAY_UNIT_NSECS:
1221                 /* Nothing to do here */
1222                 break;
1223         case SPI_DELAY_UNIT_SCK:
1224                 /* clock cycles need to be obtained from spi_transfer */
1225                 if (!xfer)
1226                         return -EINVAL;
1227                 /*
1228                  * If there is unknown effective speed, approximate it
1229                  * by underestimating with half of the requested hz.
1230                  */
1231                 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1232                 if (!hz)
1233                         return -EINVAL;
1234
1235                 /* Convert delay to nanoseconds */
1236                 delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz);
1237                 break;
1238         default:
1239                 return -EINVAL;
1240         }
1241
1242         return delay;
1243 }
1244 EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1245
1246 int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1247 {
1248         int delay;
1249
1250         might_sleep();
1251
1252         if (!_delay)
1253                 return -EINVAL;
1254
1255         delay = spi_delay_to_ns(_delay, xfer);
1256         if (delay < 0)
1257                 return delay;
1258
1259         _spi_transfer_delay_ns(delay);
1260
1261         return 0;
1262 }
1263 EXPORT_SYMBOL_GPL(spi_delay_exec);
1264
1265 static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1266                                           struct spi_transfer *xfer)
1267 {
1268         u32 default_delay_ns = 10 * NSEC_PER_USEC;
1269         u32 delay = xfer->cs_change_delay.value;
1270         u32 unit = xfer->cs_change_delay.unit;
1271         int ret;
1272
1273         /* return early on "fast" mode - for everything but USECS */
1274         if (!delay) {
1275                 if (unit == SPI_DELAY_UNIT_USECS)
1276                         _spi_transfer_delay_ns(default_delay_ns);
1277                 return;
1278         }
1279
1280         ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1281         if (ret) {
1282                 dev_err_once(&msg->spi->dev,
1283                              "Use of unsupported delay unit %i, using default of %luus\n",
1284                              unit, default_delay_ns / NSEC_PER_USEC);
1285                 _spi_transfer_delay_ns(default_delay_ns);
1286         }
1287 }
1288
1289 /*
1290  * spi_transfer_one_message - Default implementation of transfer_one_message()
1291  *
1292  * This is a standard implementation of transfer_one_message() for
1293  * drivers which implement a transfer_one() operation.  It provides
1294  * standard handling of delays and chip select management.
1295  */
1296 static int spi_transfer_one_message(struct spi_controller *ctlr,
1297                                     struct spi_message *msg)
1298 {
1299         struct spi_transfer *xfer;
1300         bool keep_cs = false;
1301         int ret = 0;
1302         struct spi_statistics *statm = &ctlr->statistics;
1303         struct spi_statistics *stats = &msg->spi->statistics;
1304
1305         spi_set_cs(msg->spi, true, false);
1306
1307         SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1308         SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1309
1310         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1311                 trace_spi_transfer_start(msg, xfer);
1312
1313                 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1314                 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1315
1316                 if (!ctlr->ptp_sts_supported) {
1317                         xfer->ptp_sts_word_pre = 0;
1318                         ptp_read_system_prets(xfer->ptp_sts);
1319                 }
1320
1321                 if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) {
1322                         reinit_completion(&ctlr->xfer_completion);
1323
1324 fallback_pio:
1325                         ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1326                         if (ret < 0) {
1327                                 if (ctlr->cur_msg_mapped &&
1328                                    (xfer->error & SPI_TRANS_FAIL_NO_START)) {
1329                                         __spi_unmap_msg(ctlr, msg);
1330                                         ctlr->fallback = true;
1331                                         xfer->error &= ~SPI_TRANS_FAIL_NO_START;
1332                                         goto fallback_pio;
1333                                 }
1334
1335                                 SPI_STATISTICS_INCREMENT_FIELD(statm,
1336                                                                errors);
1337                                 SPI_STATISTICS_INCREMENT_FIELD(stats,
1338                                                                errors);
1339                                 dev_err(&msg->spi->dev,
1340                                         "SPI transfer failed: %d\n", ret);
1341                                 goto out;
1342                         }
1343
1344                         if (ret > 0) {
1345                                 ret = spi_transfer_wait(ctlr, msg, xfer);
1346                                 if (ret < 0)
1347                                         msg->status = ret;
1348                         }
1349                 } else {
1350                         if (xfer->len)
1351                                 dev_err(&msg->spi->dev,
1352                                         "Bufferless transfer has length %u\n",
1353                                         xfer->len);
1354                 }
1355
1356                 if (!ctlr->ptp_sts_supported) {
1357                         ptp_read_system_postts(xfer->ptp_sts);
1358                         xfer->ptp_sts_word_post = xfer->len;
1359                 }
1360
1361                 trace_spi_transfer_stop(msg, xfer);
1362
1363                 if (msg->status != -EINPROGRESS)
1364                         goto out;
1365
1366                 spi_transfer_delay_exec(xfer);
1367
1368                 if (xfer->cs_change) {
1369                         if (list_is_last(&xfer->transfer_list,
1370                                          &msg->transfers)) {
1371                                 keep_cs = true;
1372                         } else {
1373                                 spi_set_cs(msg->spi, false, false);
1374                                 _spi_transfer_cs_change_delay(msg, xfer);
1375                                 spi_set_cs(msg->spi, true, false);
1376                         }
1377                 }
1378
1379                 msg->actual_length += xfer->len;
1380         }
1381
1382 out:
1383         if (ret != 0 || !keep_cs)
1384                 spi_set_cs(msg->spi, false, false);
1385
1386         if (msg->status == -EINPROGRESS)
1387                 msg->status = ret;
1388
1389         if (msg->status && ctlr->handle_err)
1390                 ctlr->handle_err(ctlr, msg);
1391
1392         spi_finalize_current_message(ctlr);
1393
1394         return ret;
1395 }
1396
1397 /**
1398  * spi_finalize_current_transfer - report completion of a transfer
1399  * @ctlr: the controller reporting completion
1400  *
1401  * Called by SPI drivers using the core transfer_one_message()
1402  * implementation to notify it that the current interrupt driven
1403  * transfer has finished and the next one may be scheduled.
1404  */
1405 void spi_finalize_current_transfer(struct spi_controller *ctlr)
1406 {
1407         complete(&ctlr->xfer_completion);
1408 }
1409 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1410
1411 static void spi_idle_runtime_pm(struct spi_controller *ctlr)
1412 {
1413         if (ctlr->auto_runtime_pm) {
1414                 pm_runtime_mark_last_busy(ctlr->dev.parent);
1415                 pm_runtime_put_autosuspend(ctlr->dev.parent);
1416         }
1417 }
1418
1419 /**
1420  * __spi_pump_messages - function which processes spi message queue
1421  * @ctlr: controller to process queue for
1422  * @in_kthread: true if we are in the context of the message pump thread
1423  *
1424  * This function checks if there is any spi message in the queue that
1425  * needs processing and if so call out to the driver to initialize hardware
1426  * and transfer each message.
1427  *
1428  * Note that it is called both from the kthread itself and also from
1429  * inside spi_sync(); the queue extraction handling at the top of the
1430  * function should deal with this safely.
1431  */
1432 static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1433 {
1434         struct spi_transfer *xfer;
1435         struct spi_message *msg;
1436         bool was_busy = false;
1437         unsigned long flags;
1438         int ret;
1439
1440         /* Lock queue */
1441         spin_lock_irqsave(&ctlr->queue_lock, flags);
1442
1443         /* Make sure we are not already running a message */
1444         if (ctlr->cur_msg) {
1445                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1446                 return;
1447         }
1448
1449         /* If another context is idling the device then defer */
1450         if (ctlr->idling) {
1451                 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1452                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1453                 return;
1454         }
1455
1456         /* Check if the queue is idle */
1457         if (list_empty(&ctlr->queue) || !ctlr->running) {
1458                 if (!ctlr->busy) {
1459                         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1460                         return;
1461                 }
1462
1463                 /* Defer any non-atomic teardown to the thread */
1464                 if (!in_kthread) {
1465                         if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
1466                             !ctlr->unprepare_transfer_hardware) {
1467                                 spi_idle_runtime_pm(ctlr);
1468                                 ctlr->busy = false;
1469                                 trace_spi_controller_idle(ctlr);
1470                         } else {
1471                                 kthread_queue_work(ctlr->kworker,
1472                                                    &ctlr->pump_messages);
1473                         }
1474                         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1475                         return;
1476                 }
1477
1478                 ctlr->busy = false;
1479                 ctlr->idling = true;
1480                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1481
1482                 kfree(ctlr->dummy_rx);
1483                 ctlr->dummy_rx = NULL;
1484                 kfree(ctlr->dummy_tx);
1485                 ctlr->dummy_tx = NULL;
1486                 if (ctlr->unprepare_transfer_hardware &&
1487                     ctlr->unprepare_transfer_hardware(ctlr))
1488                         dev_err(&ctlr->dev,
1489                                 "failed to unprepare transfer hardware\n");
1490                 spi_idle_runtime_pm(ctlr);
1491                 trace_spi_controller_idle(ctlr);
1492
1493                 spin_lock_irqsave(&ctlr->queue_lock, flags);
1494                 ctlr->idling = false;
1495                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1496                 return;
1497         }
1498
1499         /* Extract head of queue */
1500         msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1501         ctlr->cur_msg = msg;
1502
1503         list_del_init(&msg->queue);
1504         if (ctlr->busy)
1505                 was_busy = true;
1506         else
1507                 ctlr->busy = true;
1508         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1509
1510         mutex_lock(&ctlr->io_mutex);
1511
1512         if (!was_busy && ctlr->auto_runtime_pm) {
1513                 ret = pm_runtime_get_sync(ctlr->dev.parent);
1514                 if (ret < 0) {
1515                         pm_runtime_put_noidle(ctlr->dev.parent);
1516                         dev_err(&ctlr->dev, "Failed to power device: %d\n",
1517                                 ret);
1518                         mutex_unlock(&ctlr->io_mutex);
1519                         return;
1520                 }
1521         }
1522
1523         if (!was_busy)
1524                 trace_spi_controller_busy(ctlr);
1525
1526         if (!was_busy && ctlr->prepare_transfer_hardware) {
1527                 ret = ctlr->prepare_transfer_hardware(ctlr);
1528                 if (ret) {
1529                         dev_err(&ctlr->dev,
1530                                 "failed to prepare transfer hardware: %d\n",
1531                                 ret);
1532
1533                         if (ctlr->auto_runtime_pm)
1534                                 pm_runtime_put(ctlr->dev.parent);
1535
1536                         msg->status = ret;
1537                         spi_finalize_current_message(ctlr);
1538
1539                         mutex_unlock(&ctlr->io_mutex);
1540                         return;
1541                 }
1542         }
1543
1544         trace_spi_message_start(msg);
1545
1546         if (ctlr->prepare_message) {
1547                 ret = ctlr->prepare_message(ctlr, msg);
1548                 if (ret) {
1549                         dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1550                                 ret);
1551                         msg->status = ret;
1552                         spi_finalize_current_message(ctlr);
1553                         goto out;
1554                 }
1555                 ctlr->cur_msg_prepared = true;
1556         }
1557
1558         ret = spi_map_msg(ctlr, msg);
1559         if (ret) {
1560                 msg->status = ret;
1561                 spi_finalize_current_message(ctlr);
1562                 goto out;
1563         }
1564
1565         if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1566                 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1567                         xfer->ptp_sts_word_pre = 0;
1568                         ptp_read_system_prets(xfer->ptp_sts);
1569                 }
1570         }
1571
1572         ret = ctlr->transfer_one_message(ctlr, msg);
1573         if (ret) {
1574                 dev_err(&ctlr->dev,
1575                         "failed to transfer one message from queue\n");
1576                 goto out;
1577         }
1578
1579 out:
1580         mutex_unlock(&ctlr->io_mutex);
1581
1582         /* Prod the scheduler in case transfer_one() was busy waiting */
1583         if (!ret)
1584                 cond_resched();
1585 }
1586
1587 /**
1588  * spi_pump_messages - kthread work function which processes spi message queue
1589  * @work: pointer to kthread work struct contained in the controller struct
1590  */
1591 static void spi_pump_messages(struct kthread_work *work)
1592 {
1593         struct spi_controller *ctlr =
1594                 container_of(work, struct spi_controller, pump_messages);
1595
1596         __spi_pump_messages(ctlr, true);
1597 }
1598
1599 /**
1600  * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
1601  *                          TX timestamp for the requested byte from the SPI
1602  *                          transfer. The frequency with which this function
1603  *                          must be called (once per word, once for the whole
1604  *                          transfer, once per batch of words etc) is arbitrary
1605  *                          as long as the @tx buffer offset is greater than or
1606  *                          equal to the requested byte at the time of the
1607  *                          call. The timestamp is only taken once, at the
1608  *                          first such call. It is assumed that the driver
1609  *                          advances its @tx buffer pointer monotonically.
1610  * @ctlr: Pointer to the spi_controller structure of the driver
1611  * @xfer: Pointer to the transfer being timestamped
1612  * @progress: How many words (not bytes) have been transferred so far
1613  * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1614  *            transfer, for less jitter in time measurement. Only compatible
1615  *            with PIO drivers. If true, must follow up with
1616  *            spi_take_timestamp_post or otherwise system will crash.
1617  *            WARNING: for fully predictable results, the CPU frequency must
1618  *            also be under control (governor).
1619  */
1620 void spi_take_timestamp_pre(struct spi_controller *ctlr,
1621                             struct spi_transfer *xfer,
1622                             size_t progress, bool irqs_off)
1623 {
1624         if (!xfer->ptp_sts)
1625                 return;
1626
1627         if (xfer->timestamped)
1628                 return;
1629
1630         if (progress > xfer->ptp_sts_word_pre)
1631                 return;
1632
1633         /* Capture the resolution of the timestamp */
1634         xfer->ptp_sts_word_pre = progress;
1635
1636         if (irqs_off) {
1637                 local_irq_save(ctlr->irq_flags);
1638                 preempt_disable();
1639         }
1640
1641         ptp_read_system_prets(xfer->ptp_sts);
1642 }
1643 EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
1644
1645 /**
1646  * spi_take_timestamp_post - helper for drivers to collect the end of the
1647  *                           TX timestamp for the requested byte from the SPI
1648  *                           transfer. Can be called with an arbitrary
1649  *                           frequency: only the first call where @tx exceeds
1650  *                           or is equal to the requested word will be
1651  *                           timestamped.
1652  * @ctlr: Pointer to the spi_controller structure of the driver
1653  * @xfer: Pointer to the transfer being timestamped
1654  * @progress: How many words (not bytes) have been transferred so far
1655  * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1656  */
1657 void spi_take_timestamp_post(struct spi_controller *ctlr,
1658                              struct spi_transfer *xfer,
1659                              size_t progress, bool irqs_off)
1660 {
1661         if (!xfer->ptp_sts)
1662                 return;
1663
1664         if (xfer->timestamped)
1665                 return;
1666
1667         if (progress < xfer->ptp_sts_word_post)
1668                 return;
1669
1670         ptp_read_system_postts(xfer->ptp_sts);
1671
1672         if (irqs_off) {
1673                 local_irq_restore(ctlr->irq_flags);
1674                 preempt_enable();
1675         }
1676
1677         /* Capture the resolution of the timestamp */
1678         xfer->ptp_sts_word_post = progress;
1679
1680         xfer->timestamped = true;
1681 }
1682 EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
1683
1684 /**
1685  * spi_set_thread_rt - set the controller to pump at realtime priority
1686  * @ctlr: controller to boost priority of
1687  *
1688  * This can be called because the controller requested realtime priority
1689  * (by setting the ->rt value before calling spi_register_controller()) or
1690  * because a device on the bus said that its transfers needed realtime
1691  * priority.
1692  *
1693  * NOTE: at the moment if any device on a bus says it needs realtime then
1694  * the thread will be at realtime priority for all transfers on that
1695  * controller.  If this eventually becomes a problem we may see if we can
1696  * find a way to boost the priority only temporarily during relevant
1697  * transfers.
1698  */
1699 static void spi_set_thread_rt(struct spi_controller *ctlr)
1700 {
1701         dev_info(&ctlr->dev,
1702                 "will run message pump with realtime priority\n");
1703         sched_set_fifo(ctlr->kworker->task);
1704 }
1705
1706 static int spi_init_queue(struct spi_controller *ctlr)
1707 {
1708         ctlr->running = false;
1709         ctlr->busy = false;
1710
1711         ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
1712         if (IS_ERR(ctlr->kworker)) {
1713                 dev_err(&ctlr->dev, "failed to create message pump kworker\n");
1714                 return PTR_ERR(ctlr->kworker);
1715         }
1716
1717         kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1718
1719         /*
1720          * Controller config will indicate if this controller should run the
1721          * message pump with high (realtime) priority to reduce the transfer
1722          * latency on the bus by minimising the delay between a transfer
1723          * request and the scheduling of the message pump thread. Without this
1724          * setting the message pump thread will remain at default priority.
1725          */
1726         if (ctlr->rt)
1727                 spi_set_thread_rt(ctlr);
1728
1729         return 0;
1730 }
1731
1732 /**
1733  * spi_get_next_queued_message() - called by driver to check for queued
1734  * messages
1735  * @ctlr: the controller to check for queued messages
1736  *
1737  * If there are more messages in the queue, the next message is returned from
1738  * this call.
1739  *
1740  * Return: the next message in the queue, else NULL if the queue is empty.
1741  */
1742 struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1743 {
1744         struct spi_message *next;
1745         unsigned long flags;
1746
1747         /* get a pointer to the next message, if any */
1748         spin_lock_irqsave(&ctlr->queue_lock, flags);
1749         next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1750                                         queue);
1751         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1752
1753         return next;
1754 }
1755 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1756
1757 /**
1758  * spi_finalize_current_message() - the current message is complete
1759  * @ctlr: the controller to return the message to
1760  *
1761  * Called by the driver to notify the core that the message in the front of the
1762  * queue is complete and can be removed from the queue.
1763  */
1764 void spi_finalize_current_message(struct spi_controller *ctlr)
1765 {
1766         struct spi_transfer *xfer;
1767         struct spi_message *mesg;
1768         unsigned long flags;
1769         int ret;
1770
1771         spin_lock_irqsave(&ctlr->queue_lock, flags);
1772         mesg = ctlr->cur_msg;
1773         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1774
1775         if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1776                 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
1777                         ptp_read_system_postts(xfer->ptp_sts);
1778                         xfer->ptp_sts_word_post = xfer->len;
1779                 }
1780         }
1781
1782         if (unlikely(ctlr->ptp_sts_supported))
1783                 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
1784                         WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
1785
1786         spi_unmap_msg(ctlr, mesg);
1787
1788         /* In the prepare_messages callback the spi bus has the opportunity to
1789          * split a transfer to smaller chunks.
1790          * Release splited transfers here since spi_map_msg is done on the
1791          * splited transfers.
1792          */
1793         spi_res_release(ctlr, mesg);
1794
1795         if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1796                 ret = ctlr->unprepare_message(ctlr, mesg);
1797                 if (ret) {
1798                         dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1799                                 ret);
1800                 }
1801         }
1802
1803         spin_lock_irqsave(&ctlr->queue_lock, flags);
1804         ctlr->cur_msg = NULL;
1805         ctlr->cur_msg_prepared = false;
1806         ctlr->fallback = false;
1807         kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1808         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1809
1810         trace_spi_message_done(mesg);
1811
1812         mesg->state = NULL;
1813         if (mesg->complete)
1814                 mesg->complete(mesg->context);
1815 }
1816 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1817
1818 static int spi_start_queue(struct spi_controller *ctlr)
1819 {
1820         unsigned long flags;
1821
1822         spin_lock_irqsave(&ctlr->queue_lock, flags);
1823
1824         if (ctlr->running || ctlr->busy) {
1825                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1826                 return -EBUSY;
1827         }
1828
1829         ctlr->running = true;
1830         ctlr->cur_msg = NULL;
1831         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1832
1833         kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1834
1835         return 0;
1836 }
1837
1838 static int spi_stop_queue(struct spi_controller *ctlr)
1839 {
1840         unsigned long flags;
1841         unsigned limit = 500;
1842         int ret = 0;
1843
1844         spin_lock_irqsave(&ctlr->queue_lock, flags);
1845
1846         /*
1847          * This is a bit lame, but is optimized for the common execution path.
1848          * A wait_queue on the ctlr->busy could be used, but then the common
1849          * execution path (pump_messages) would be required to call wake_up or
1850          * friends on every SPI message. Do this instead.
1851          */
1852         while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1853                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1854                 usleep_range(10000, 11000);
1855                 spin_lock_irqsave(&ctlr->queue_lock, flags);
1856         }
1857
1858         if (!list_empty(&ctlr->queue) || ctlr->busy)
1859                 ret = -EBUSY;
1860         else
1861                 ctlr->running = false;
1862
1863         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1864
1865         if (ret) {
1866                 dev_warn(&ctlr->dev, "could not stop message queue\n");
1867                 return ret;
1868         }
1869         return ret;
1870 }
1871
1872 static int spi_destroy_queue(struct spi_controller *ctlr)
1873 {
1874         int ret;
1875
1876         ret = spi_stop_queue(ctlr);
1877
1878         /*
1879          * kthread_flush_worker will block until all work is done.
1880          * If the reason that stop_queue timed out is that the work will never
1881          * finish, then it does no good to call flush/stop thread, so
1882          * return anyway.
1883          */
1884         if (ret) {
1885                 dev_err(&ctlr->dev, "problem destroying queue\n");
1886                 return ret;
1887         }
1888
1889         kthread_destroy_worker(ctlr->kworker);
1890
1891         return 0;
1892 }
1893
1894 static int __spi_queued_transfer(struct spi_device *spi,
1895                                  struct spi_message *msg,
1896                                  bool need_pump)
1897 {
1898         struct spi_controller *ctlr = spi->controller;
1899         unsigned long flags;
1900
1901         spin_lock_irqsave(&ctlr->queue_lock, flags);
1902
1903         if (!ctlr->running) {
1904                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1905                 return -ESHUTDOWN;
1906         }
1907         msg->actual_length = 0;
1908         msg->status = -EINPROGRESS;
1909
1910         list_add_tail(&msg->queue, &ctlr->queue);
1911         if (!ctlr->busy && need_pump)
1912                 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1913
1914         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1915         return 0;
1916 }
1917
1918 /**
1919  * spi_queued_transfer - transfer function for queued transfers
1920  * @spi: spi device which is requesting transfer
1921  * @msg: spi message which is to handled is queued to driver queue
1922  *
1923  * Return: zero on success, else a negative error code.
1924  */
1925 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1926 {
1927         return __spi_queued_transfer(spi, msg, true);
1928 }
1929
1930 static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1931 {
1932         int ret;
1933
1934         ctlr->transfer = spi_queued_transfer;
1935         if (!ctlr->transfer_one_message)
1936                 ctlr->transfer_one_message = spi_transfer_one_message;
1937
1938         /* Initialize and start queue */
1939         ret = spi_init_queue(ctlr);
1940         if (ret) {
1941                 dev_err(&ctlr->dev, "problem initializing queue\n");
1942                 goto err_init_queue;
1943         }
1944         ctlr->queued = true;
1945         ret = spi_start_queue(ctlr);
1946         if (ret) {
1947                 dev_err(&ctlr->dev, "problem starting queue\n");
1948                 goto err_start_queue;
1949         }
1950
1951         return 0;
1952
1953 err_start_queue:
1954         spi_destroy_queue(ctlr);
1955 err_init_queue:
1956         return ret;
1957 }
1958
1959 /**
1960  * spi_flush_queue - Send all pending messages in the queue from the callers'
1961  *                   context
1962  * @ctlr: controller to process queue for
1963  *
1964  * This should be used when one wants to ensure all pending messages have been
1965  * sent before doing something. Is used by the spi-mem code to make sure SPI
1966  * memory operations do not preempt regular SPI transfers that have been queued
1967  * before the spi-mem operation.
1968  */
1969 void spi_flush_queue(struct spi_controller *ctlr)
1970 {
1971         if (ctlr->transfer == spi_queued_transfer)
1972                 __spi_pump_messages(ctlr, false);
1973 }
1974
1975 /*-------------------------------------------------------------------------*/
1976
1977 #if defined(CONFIG_OF)
1978 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1979                            struct device_node *nc)
1980 {
1981         u32 value;
1982         int rc;
1983
1984         /* Mode (clock phase/polarity/etc.) */
1985         if (of_property_read_bool(nc, "spi-cpha"))
1986                 spi->mode |= SPI_CPHA;
1987         if (of_property_read_bool(nc, "spi-cpol"))
1988                 spi->mode |= SPI_CPOL;
1989         if (of_property_read_bool(nc, "spi-3wire"))
1990                 spi->mode |= SPI_3WIRE;
1991         if (of_property_read_bool(nc, "spi-lsb-first"))
1992                 spi->mode |= SPI_LSB_FIRST;
1993         if (of_property_read_bool(nc, "spi-cs-high"))
1994                 spi->mode |= SPI_CS_HIGH;
1995
1996         /* Device DUAL/QUAD mode */
1997         if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1998                 switch (value) {
1999                 case 0:
2000                         spi->mode |= SPI_NO_TX;
2001                         break;
2002                 case 1:
2003                         break;
2004                 case 2:
2005                         spi->mode |= SPI_TX_DUAL;
2006                         break;
2007                 case 4:
2008                         spi->mode |= SPI_TX_QUAD;
2009                         break;
2010                 case 8:
2011                         spi->mode |= SPI_TX_OCTAL;
2012                         break;
2013                 default:
2014                         dev_warn(&ctlr->dev,
2015                                 "spi-tx-bus-width %d not supported\n",
2016                                 value);
2017                         break;
2018                 }
2019         }
2020
2021         if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
2022                 switch (value) {
2023                 case 0:
2024                         spi->mode |= SPI_NO_RX;
2025                         break;
2026                 case 1:
2027                         break;
2028                 case 2:
2029                         spi->mode |= SPI_RX_DUAL;
2030                         break;
2031                 case 4:
2032                         spi->mode |= SPI_RX_QUAD;
2033                         break;
2034                 case 8:
2035                         spi->mode |= SPI_RX_OCTAL;
2036                         break;
2037                 default:
2038                         dev_warn(&ctlr->dev,
2039                                 "spi-rx-bus-width %d not supported\n",
2040                                 value);
2041                         break;
2042                 }
2043         }
2044
2045         if (spi_controller_is_slave(ctlr)) {
2046                 if (!of_node_name_eq(nc, "slave")) {
2047                         dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
2048                                 nc);
2049                         return -EINVAL;
2050                 }
2051                 return 0;
2052         }
2053
2054         /* Device address */
2055         rc = of_property_read_u32(nc, "reg", &value);
2056         if (rc) {
2057                 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
2058                         nc, rc);
2059                 return rc;
2060         }
2061         spi->chip_select = value;
2062
2063         /* Device speed */
2064         if (!of_property_read_u32(nc, "spi-max-frequency", &value))
2065                 spi->max_speed_hz = value;
2066
2067         return 0;
2068 }
2069
2070 static struct spi_device *
2071 of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
2072 {
2073         struct spi_device *spi;
2074         int rc;
2075
2076         /* Alloc an spi_device */
2077         spi = spi_alloc_device(ctlr);
2078         if (!spi) {
2079                 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
2080                 rc = -ENOMEM;
2081                 goto err_out;
2082         }
2083
2084         /* Select device driver */
2085         rc = of_modalias_node(nc, spi->modalias,
2086                                 sizeof(spi->modalias));
2087         if (rc < 0) {
2088                 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
2089                 goto err_out;
2090         }
2091
2092         rc = of_spi_parse_dt(ctlr, spi, nc);
2093         if (rc)
2094                 goto err_out;
2095
2096         /* Store a pointer to the node in the device structure */
2097         of_node_get(nc);
2098         spi->dev.of_node = nc;
2099         spi->dev.fwnode = of_fwnode_handle(nc);
2100
2101         /* Register the new device */
2102         rc = spi_add_device(spi);
2103         if (rc) {
2104                 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
2105                 goto err_of_node_put;
2106         }
2107
2108         return spi;
2109
2110 err_of_node_put:
2111         of_node_put(nc);
2112 err_out:
2113         spi_dev_put(spi);
2114         return ERR_PTR(rc);
2115 }
2116
2117 /**
2118  * of_register_spi_devices() - Register child devices onto the SPI bus
2119  * @ctlr:       Pointer to spi_controller device
2120  *
2121  * Registers an spi_device for each child node of controller node which
2122  * represents a valid SPI slave.
2123  */
2124 static void of_register_spi_devices(struct spi_controller *ctlr)
2125 {
2126         struct spi_device *spi;
2127         struct device_node *nc;
2128
2129         if (!ctlr->dev.of_node)
2130                 return;
2131
2132         for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2133                 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2134                         continue;
2135                 spi = of_register_spi_device(ctlr, nc);
2136                 if (IS_ERR(spi)) {
2137                         dev_warn(&ctlr->dev,
2138                                  "Failed to create SPI device for %pOF\n", nc);
2139                         of_node_clear_flag(nc, OF_POPULATED);
2140                 }
2141         }
2142 }
2143 #else
2144 static void of_register_spi_devices(struct spi_controller *ctlr) { }
2145 #endif
2146
2147 /**
2148  * spi_new_ancillary_device() - Register ancillary SPI device
2149  * @spi:         Pointer to the main SPI device registering the ancillary device
2150  * @chip_select: Chip Select of the ancillary device
2151  *
2152  * Register an ancillary SPI device; for example some chips have a chip-select
2153  * for normal device usage and another one for setup/firmware upload.
2154  *
2155  * This may only be called from main SPI device's probe routine.
2156  *
2157  * Return: 0 on success; negative errno on failure
2158  */
2159 struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
2160                                              u8 chip_select)
2161 {
2162         struct spi_device *ancillary;
2163         int rc = 0;
2164
2165         /* Alloc an spi_device */
2166         ancillary = spi_alloc_device(spi->controller);
2167         if (!ancillary) {
2168                 rc = -ENOMEM;
2169                 goto err_out;
2170         }
2171
2172         strlcpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));
2173
2174         /* Use provided chip-select for ancillary device */
2175         ancillary->chip_select = chip_select;
2176
2177         /* Take over SPI mode/speed from SPI main device */
2178         ancillary->max_speed_hz = spi->max_speed_hz;
2179         ancillary->mode = spi->mode;
2180
2181         /* Register the new device */
2182         rc = spi_add_device_locked(ancillary);
2183         if (rc) {
2184                 dev_err(&spi->dev, "failed to register ancillary device\n");
2185                 goto err_out;
2186         }
2187
2188         return ancillary;
2189
2190 err_out:
2191         spi_dev_put(ancillary);
2192         return ERR_PTR(rc);
2193 }
2194 EXPORT_SYMBOL_GPL(spi_new_ancillary_device);
2195
2196 #ifdef CONFIG_ACPI
2197 struct acpi_spi_lookup {
2198         struct spi_controller   *ctlr;
2199         u32                     max_speed_hz;
2200         u32                     mode;
2201         int                     irq;
2202         u8                      bits_per_word;
2203         u8                      chip_select;
2204 };
2205
2206 static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2207                                             struct acpi_spi_lookup *lookup)
2208 {
2209         const union acpi_object *obj;
2210
2211         if (!x86_apple_machine)
2212                 return;
2213
2214         if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2215             && obj->buffer.length >= 4)
2216                 lookup->max_speed_hz  = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2217
2218         if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2219             && obj->buffer.length == 8)
2220                 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2221
2222         if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2223             && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2224                 lookup->mode |= SPI_LSB_FIRST;
2225
2226         if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2227             && obj->buffer.length == 8 &&  *(u64 *)obj->buffer.pointer)
2228                 lookup->mode |= SPI_CPOL;
2229
2230         if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2231             && obj->buffer.length == 8 &&  *(u64 *)obj->buffer.pointer)
2232                 lookup->mode |= SPI_CPHA;
2233 }
2234
2235 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2236 {
2237         struct acpi_spi_lookup *lookup = data;
2238         struct spi_controller *ctlr = lookup->ctlr;
2239
2240         if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2241                 struct acpi_resource_spi_serialbus *sb;
2242                 acpi_handle parent_handle;
2243                 acpi_status status;
2244
2245                 sb = &ares->data.spi_serial_bus;
2246                 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2247
2248                         status = acpi_get_handle(NULL,
2249                                                  sb->resource_source.string_ptr,
2250                                                  &parent_handle);
2251
2252                         if (ACPI_FAILURE(status) ||
2253                             ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
2254                                 return -ENODEV;
2255
2256                         /*
2257                          * ACPI DeviceSelection numbering is handled by the
2258                          * host controller driver in Windows and can vary
2259                          * from driver to driver. In Linux we always expect
2260                          * 0 .. max - 1 so we need to ask the driver to
2261                          * translate between the two schemes.
2262                          */
2263                         if (ctlr->fw_translate_cs) {
2264                                 int cs = ctlr->fw_translate_cs(ctlr,
2265                                                 sb->device_selection);
2266                                 if (cs < 0)
2267                                         return cs;
2268                                 lookup->chip_select = cs;
2269                         } else {
2270                                 lookup->chip_select = sb->device_selection;
2271                         }
2272
2273                         lookup->max_speed_hz = sb->connection_speed;
2274                         lookup->bits_per_word = sb->data_bit_length;
2275
2276                         if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2277                                 lookup->mode |= SPI_CPHA;
2278                         if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2279                                 lookup->mode |= SPI_CPOL;
2280                         if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2281                                 lookup->mode |= SPI_CS_HIGH;
2282                 }
2283         } else if (lookup->irq < 0) {
2284                 struct resource r;
2285
2286                 if (acpi_dev_resource_interrupt(ares, 0, &r))
2287                         lookup->irq = r.start;
2288         }
2289
2290         /* Always tell the ACPI core to skip this resource */
2291         return 1;
2292 }
2293
2294 static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2295                                             struct acpi_device *adev)
2296 {
2297         acpi_handle parent_handle = NULL;
2298         struct list_head resource_list;
2299         struct acpi_spi_lookup lookup = {};
2300         struct spi_device *spi;
2301         int ret;
2302
2303         if (acpi_bus_get_status(adev) || !adev->status.present ||
2304             acpi_device_enumerated(adev))
2305                 return AE_OK;
2306
2307         lookup.ctlr             = ctlr;
2308         lookup.irq              = -1;
2309
2310         INIT_LIST_HEAD(&resource_list);
2311         ret = acpi_dev_get_resources(adev, &resource_list,
2312                                      acpi_spi_add_resource, &lookup);
2313         acpi_dev_free_resource_list(&resource_list);
2314
2315         if (ret < 0)
2316                 /* found SPI in _CRS but it points to another controller */
2317                 return AE_OK;
2318
2319         if (!lookup.max_speed_hz &&
2320             ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
2321             ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {
2322                 /* Apple does not use _CRS but nested devices for SPI slaves */
2323                 acpi_spi_parse_apple_properties(adev, &lookup);
2324         }
2325
2326         if (!lookup.max_speed_hz)
2327                 return AE_OK;
2328
2329         spi = spi_alloc_device(ctlr);
2330         if (!spi) {
2331                 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
2332                         dev_name(&adev->dev));
2333                 return AE_NO_MEMORY;
2334         }
2335
2336
2337         ACPI_COMPANION_SET(&spi->dev, adev);
2338         spi->max_speed_hz       = lookup.max_speed_hz;
2339         spi->mode               |= lookup.mode;
2340         spi->irq                = lookup.irq;
2341         spi->bits_per_word      = lookup.bits_per_word;
2342         spi->chip_select        = lookup.chip_select;
2343
2344         acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2345                           sizeof(spi->modalias));
2346
2347         if (spi->irq < 0)
2348                 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
2349
2350         acpi_device_set_enumerated(adev);
2351
2352         adev->power.flags.ignore_parent = true;
2353         if (spi_add_device(spi)) {
2354                 adev->power.flags.ignore_parent = false;
2355                 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2356                         dev_name(&adev->dev));
2357                 spi_dev_put(spi);
2358         }
2359
2360         return AE_OK;
2361 }
2362
2363 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2364                                        void *data, void **return_value)
2365 {
2366         struct spi_controller *ctlr = data;
2367         struct acpi_device *adev;
2368
2369         if (acpi_bus_get_device(handle, &adev))
2370                 return AE_OK;
2371
2372         return acpi_register_spi_device(ctlr, adev);
2373 }
2374
2375 #define SPI_ACPI_ENUMERATE_MAX_DEPTH            32
2376
2377 static void acpi_register_spi_devices(struct spi_controller *ctlr)
2378 {
2379         acpi_status status;
2380         acpi_handle handle;
2381
2382         handle = ACPI_HANDLE(ctlr->dev.parent);
2383         if (!handle)
2384                 return;
2385
2386         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2387                                      SPI_ACPI_ENUMERATE_MAX_DEPTH,
2388                                      acpi_spi_add_device, NULL, ctlr, NULL);
2389         if (ACPI_FAILURE(status))
2390                 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2391 }
2392 #else
2393 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2394 #endif /* CONFIG_ACPI */
2395
2396 static void spi_controller_release(struct device *dev)
2397 {
2398         struct spi_controller *ctlr;
2399
2400         ctlr = container_of(dev, struct spi_controller, dev);
2401         kfree(ctlr);
2402 }
2403
2404 static struct class spi_master_class = {
2405         .name           = "spi_master",
2406         .owner          = THIS_MODULE,
2407         .dev_release    = spi_controller_release,
2408         .dev_groups     = spi_master_groups,
2409 };
2410
2411 #ifdef CONFIG_SPI_SLAVE
2412 /**
2413  * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2414  *                   controller
2415  * @spi: device used for the current transfer
2416  */
2417 int spi_slave_abort(struct spi_device *spi)
2418 {
2419         struct spi_controller *ctlr = spi->controller;
2420
2421         if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
2422                 return ctlr->slave_abort(ctlr);
2423
2424         return -ENOTSUPP;
2425 }
2426 EXPORT_SYMBOL_GPL(spi_slave_abort);
2427
2428 static int match_true(struct device *dev, void *data)
2429 {
2430         return 1;
2431 }
2432
2433 static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2434                           char *buf)
2435 {
2436         struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2437                                                    dev);
2438         struct device *child;
2439
2440         child = device_find_child(&ctlr->dev, NULL, match_true);
2441         return sprintf(buf, "%s\n",
2442                        child ? to_spi_device(child)->modalias : NULL);
2443 }
2444
2445 static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
2446                            const char *buf, size_t count)
2447 {
2448         struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2449                                                    dev);
2450         struct spi_device *spi;
2451         struct device *child;
2452         char name[32];
2453         int rc;
2454
2455         rc = sscanf(buf, "%31s", name);
2456         if (rc != 1 || !name[0])
2457                 return -EINVAL;
2458
2459         child = device_find_child(&ctlr->dev, NULL, match_true);
2460         if (child) {
2461                 /* Remove registered slave */
2462                 device_unregister(child);
2463                 put_device(child);
2464         }
2465
2466         if (strcmp(name, "(null)")) {
2467                 /* Register new slave */
2468                 spi = spi_alloc_device(ctlr);
2469                 if (!spi)
2470                         return -ENOMEM;
2471
2472                 strlcpy(spi->modalias, name, sizeof(spi->modalias));
2473
2474                 rc = spi_add_device(spi);
2475                 if (rc) {
2476                         spi_dev_put(spi);
2477                         return rc;
2478                 }
2479         }
2480
2481         return count;
2482 }
2483
2484 static DEVICE_ATTR_RW(slave);
2485
2486 static struct attribute *spi_slave_attrs[] = {
2487         &dev_attr_slave.attr,
2488         NULL,
2489 };
2490
2491 static const struct attribute_group spi_slave_group = {
2492         .attrs = spi_slave_attrs,
2493 };
2494
2495 static const struct attribute_group *spi_slave_groups[] = {
2496         &spi_controller_statistics_group,
2497         &spi_slave_group,
2498         NULL,
2499 };
2500
2501 static struct class spi_slave_class = {
2502         .name           = "spi_slave",
2503         .owner          = THIS_MODULE,
2504         .dev_release    = spi_controller_release,
2505         .dev_groups     = spi_slave_groups,
2506 };
2507 #else
2508 extern struct class spi_slave_class;    /* dummy */
2509 #endif
2510
2511 /**
2512  * __spi_alloc_controller - allocate an SPI master or slave controller
2513  * @dev: the controller, possibly using the platform_bus
2514  * @size: how much zeroed driver-private data to allocate; the pointer to this
2515  *      memory is in the driver_data field of the returned device, accessible
2516  *      with spi_controller_get_devdata(); the memory is cacheline aligned;
2517  *      drivers granting DMA access to portions of their private data need to
2518  *      round up @size using ALIGN(size, dma_get_cache_alignment()).
2519  * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2520  *      slave (true) controller
2521  * Context: can sleep
2522  *
2523  * This call is used only by SPI controller drivers, which are the
2524  * only ones directly touching chip registers.  It's how they allocate
2525  * an spi_controller structure, prior to calling spi_register_controller().
2526  *
2527  * This must be called from context that can sleep.
2528  *
2529  * The caller is responsible for assigning the bus number and initializing the
2530  * controller's methods before calling spi_register_controller(); and (after
2531  * errors adding the device) calling spi_controller_put() to prevent a memory
2532  * leak.
2533  *
2534  * Return: the SPI controller structure on success, else NULL.
2535  */
2536 struct spi_controller *__spi_alloc_controller(struct device *dev,
2537                                               unsigned int size, bool slave)
2538 {
2539         struct spi_controller   *ctlr;
2540         size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
2541
2542         if (!dev)
2543                 return NULL;
2544
2545         ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
2546         if (!ctlr)
2547                 return NULL;
2548
2549         device_initialize(&ctlr->dev);
2550         INIT_LIST_HEAD(&ctlr->queue);
2551         spin_lock_init(&ctlr->queue_lock);
2552         spin_lock_init(&ctlr->bus_lock_spinlock);
2553         mutex_init(&ctlr->bus_lock_mutex);
2554         mutex_init(&ctlr->io_mutex);
2555         mutex_init(&ctlr->add_lock);
2556         ctlr->bus_num = -1;
2557         ctlr->num_chipselect = 1;
2558         ctlr->slave = slave;
2559         if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2560                 ctlr->dev.class = &spi_slave_class;
2561         else
2562                 ctlr->dev.class = &spi_master_class;
2563         ctlr->dev.parent = dev;
2564         pm_suspend_ignore_children(&ctlr->dev, true);
2565         spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
2566
2567         return ctlr;
2568 }
2569 EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2570
2571 static void devm_spi_release_controller(struct device *dev, void *ctlr)
2572 {
2573         spi_controller_put(*(struct spi_controller **)ctlr);
2574 }
2575
2576 /**
2577  * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
2578  * @dev: physical device of SPI controller
2579  * @size: how much zeroed driver-private data to allocate
2580  * @slave: whether to allocate an SPI master (false) or SPI slave (true)
2581  * Context: can sleep
2582  *
2583  * Allocate an SPI controller and automatically release a reference on it
2584  * when @dev is unbound from its driver.  Drivers are thus relieved from
2585  * having to call spi_controller_put().
2586  *
2587  * The arguments to this function are identical to __spi_alloc_controller().
2588  *
2589  * Return: the SPI controller structure on success, else NULL.
2590  */
2591 struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
2592                                                    unsigned int size,
2593                                                    bool slave)
2594 {
2595         struct spi_controller **ptr, *ctlr;
2596
2597         ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),
2598                            GFP_KERNEL);
2599         if (!ptr)
2600                 return NULL;
2601
2602         ctlr = __spi_alloc_controller(dev, size, slave);
2603         if (ctlr) {
2604                 ctlr->devm_allocated = true;
2605                 *ptr = ctlr;
2606                 devres_add(dev, ptr);
2607         } else {
2608                 devres_free(ptr);
2609         }
2610
2611         return ctlr;
2612 }
2613 EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);
2614
2615 #ifdef CONFIG_OF
2616 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2617 {
2618         int nb, i, *cs;
2619         struct device_node *np = ctlr->dev.of_node;
2620
2621         if (!np)
2622                 return 0;
2623
2624         nb = of_gpio_named_count(np, "cs-gpios");
2625         ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2626
2627         /* Return error only for an incorrectly formed cs-gpios property */
2628         if (nb == 0 || nb == -ENOENT)
2629                 return 0;
2630         else if (nb < 0)
2631                 return nb;
2632
2633         cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2634                           GFP_KERNEL);
2635         ctlr->cs_gpios = cs;
2636
2637         if (!ctlr->cs_gpios)
2638                 return -ENOMEM;
2639
2640         for (i = 0; i < ctlr->num_chipselect; i++)
2641                 cs[i] = -ENOENT;
2642
2643         for (i = 0; i < nb; i++)
2644                 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2645
2646         return 0;
2647 }
2648 #else
2649 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2650 {
2651         return 0;
2652 }
2653 #endif
2654
2655 /**
2656  * spi_get_gpio_descs() - grab chip select GPIOs for the master
2657  * @ctlr: The SPI master to grab GPIO descriptors for
2658  */
2659 static int spi_get_gpio_descs(struct spi_controller *ctlr)
2660 {
2661         int nb, i;
2662         struct gpio_desc **cs;
2663         struct device *dev = &ctlr->dev;
2664         unsigned long native_cs_mask = 0;
2665         unsigned int num_cs_gpios = 0;
2666
2667         nb = gpiod_count(dev, "cs");
2668         if (nb < 0) {
2669                 /* No GPIOs at all is fine, else return the error */
2670                 if (nb == -ENOENT)
2671                         return 0;
2672                 return nb;
2673         }
2674
2675         ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2676
2677         cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
2678                           GFP_KERNEL);
2679         if (!cs)
2680                 return -ENOMEM;
2681         ctlr->cs_gpiods = cs;
2682
2683         for (i = 0; i < nb; i++) {
2684                 /*
2685                  * Most chipselects are active low, the inverted
2686                  * semantics are handled by special quirks in gpiolib,
2687                  * so initializing them GPIOD_OUT_LOW here means
2688                  * "unasserted", in most cases this will drive the physical
2689                  * line high.
2690                  */
2691                 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
2692                                                       GPIOD_OUT_LOW);
2693                 if (IS_ERR(cs[i]))
2694                         return PTR_ERR(cs[i]);
2695
2696                 if (cs[i]) {
2697                         /*
2698                          * If we find a CS GPIO, name it after the device and
2699                          * chip select line.
2700                          */
2701                         char *gpioname;
2702
2703                         gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
2704                                                   dev_name(dev), i);
2705                         if (!gpioname)
2706                                 return -ENOMEM;
2707                         gpiod_set_consumer_name(cs[i], gpioname);
2708                         num_cs_gpios++;
2709                         continue;
2710                 }
2711
2712                 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
2713                         dev_err(dev, "Invalid native chip select %d\n", i);
2714                         return -EINVAL;
2715                 }
2716                 native_cs_mask |= BIT(i);
2717         }
2718
2719         ctlr->unused_native_cs = ffs(~native_cs_mask) - 1;
2720
2721         if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios &&
2722             ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {
2723                 dev_err(dev, "No unused native chip select available\n");
2724                 return -EINVAL;
2725         }
2726
2727         return 0;
2728 }
2729
2730 static int spi_controller_check_ops(struct spi_controller *ctlr)
2731 {
2732         /*
2733          * The controller may implement only the high-level SPI-memory like
2734          * operations if it does not support regular SPI transfers, and this is
2735          * valid use case.
2736          * If ->mem_ops is NULL, we request that at least one of the
2737          * ->transfer_xxx() method be implemented.
2738          */
2739         if (ctlr->mem_ops) {
2740                 if (!ctlr->mem_ops->exec_op)
2741                         return -EINVAL;
2742         } else if (!ctlr->transfer && !ctlr->transfer_one &&
2743                    !ctlr->transfer_one_message) {
2744                 return -EINVAL;
2745         }
2746
2747         return 0;
2748 }
2749
2750 /**
2751  * spi_register_controller - register SPI master or slave controller
2752  * @ctlr: initialized master, originally from spi_alloc_master() or
2753  *      spi_alloc_slave()
2754  * Context: can sleep
2755  *
2756  * SPI controllers connect to their drivers using some non-SPI bus,
2757  * such as the platform bus.  The final stage of probe() in that code
2758  * includes calling spi_register_controller() to hook up to this SPI bus glue.
2759  *
2760  * SPI controllers use board specific (often SOC specific) bus numbers,
2761  * and board-specific addressing for SPI devices combines those numbers
2762  * with chip select numbers.  Since SPI does not directly support dynamic
2763  * device identification, boards need configuration tables telling which
2764  * chip is at which address.
2765  *
2766  * This must be called from context that can sleep.  It returns zero on
2767  * success, else a negative error code (dropping the controller's refcount).
2768  * After a successful return, the caller is responsible for calling
2769  * spi_unregister_controller().
2770  *
2771  * Return: zero on success, else a negative error code.
2772  */
2773 int spi_register_controller(struct spi_controller *ctlr)
2774 {
2775         struct device           *dev = ctlr->dev.parent;
2776         struct boardinfo        *bi;
2777         int                     status;
2778         int                     id, first_dynamic;
2779
2780         if (!dev)
2781                 return -ENODEV;
2782
2783         /*
2784          * Make sure all necessary hooks are implemented before registering
2785          * the SPI controller.
2786          */
2787         status = spi_controller_check_ops(ctlr);
2788         if (status)
2789                 return status;
2790
2791         if (ctlr->bus_num >= 0) {
2792                 /* devices with a fixed bus num must check-in with the num */
2793                 mutex_lock(&board_lock);
2794                 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2795                         ctlr->bus_num + 1, GFP_KERNEL);
2796                 mutex_unlock(&board_lock);
2797                 if (WARN(id < 0, "couldn't get idr"))
2798                         return id == -ENOSPC ? -EBUSY : id;
2799                 ctlr->bus_num = id;
2800         } else if (ctlr->dev.of_node) {
2801                 /* allocate dynamic bus number using Linux idr */
2802                 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2803                 if (id >= 0) {
2804                         ctlr->bus_num = id;
2805                         mutex_lock(&board_lock);
2806                         id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2807                                        ctlr->bus_num + 1, GFP_KERNEL);
2808                         mutex_unlock(&board_lock);
2809                         if (WARN(id < 0, "couldn't get idr"))
2810                                 return id == -ENOSPC ? -EBUSY : id;
2811                 }
2812         }
2813         if (ctlr->bus_num < 0) {
2814                 first_dynamic = of_alias_get_highest_id("spi");
2815                 if (first_dynamic < 0)
2816                         first_dynamic = 0;
2817                 else
2818                         first_dynamic++;
2819
2820                 mutex_lock(&board_lock);
2821                 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2822                                0, GFP_KERNEL);
2823                 mutex_unlock(&board_lock);
2824                 if (WARN(id < 0, "couldn't get idr"))
2825                         return id;
2826                 ctlr->bus_num = id;
2827         }
2828         ctlr->bus_lock_flag = 0;
2829         init_completion(&ctlr->xfer_completion);
2830         if (!ctlr->max_dma_len)
2831                 ctlr->max_dma_len = INT_MAX;
2832
2833         /* register the device, then userspace will see it.
2834          * registration fails if the bus ID is in use.
2835          */
2836         dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2837
2838         if (!spi_controller_is_slave(ctlr)) {
2839                 if (ctlr->use_gpio_descriptors) {
2840                         status = spi_get_gpio_descs(ctlr);
2841                         if (status)
2842                                 goto free_bus_id;
2843                         /*
2844                          * A controller using GPIO descriptors always
2845                          * supports SPI_CS_HIGH if need be.
2846                          */
2847                         ctlr->mode_bits |= SPI_CS_HIGH;
2848                 } else {
2849                         /* Legacy code path for GPIOs from DT */
2850                         status = of_spi_get_gpio_numbers(ctlr);
2851                         if (status)
2852                                 goto free_bus_id;
2853                 }
2854         }
2855
2856         /*
2857          * Even if it's just one always-selected device, there must
2858          * be at least one chipselect.
2859          */
2860         if (!ctlr->num_chipselect) {
2861                 status = -EINVAL;
2862                 goto free_bus_id;
2863         }
2864
2865         status = device_add(&ctlr->dev);
2866         if (status < 0)
2867                 goto free_bus_id;
2868         dev_dbg(dev, "registered %s %s\n",
2869                         spi_controller_is_slave(ctlr) ? "slave" : "master",
2870                         dev_name(&ctlr->dev));
2871
2872         /*
2873          * If we're using a queued driver, start the queue. Note that we don't
2874          * need the queueing logic if the driver is only supporting high-level
2875          * memory operations.
2876          */
2877         if (ctlr->transfer) {
2878                 dev_info(dev, "controller is unqueued, this is deprecated\n");
2879         } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2880                 status = spi_controller_initialize_queue(ctlr);
2881                 if (status) {
2882                         device_del(&ctlr->dev);
2883                         goto free_bus_id;
2884                 }
2885         }
2886         /* add statistics */
2887         spin_lock_init(&ctlr->statistics.lock);
2888
2889         mutex_lock(&board_lock);
2890         list_add_tail(&ctlr->list, &spi_controller_list);
2891         list_for_each_entry(bi, &board_list, list)
2892                 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2893         mutex_unlock(&board_lock);
2894
2895         /* Register devices from the device tree and ACPI */
2896         of_register_spi_devices(ctlr);
2897         acpi_register_spi_devices(ctlr);
2898         return status;
2899
2900 free_bus_id:
2901         mutex_lock(&board_lock);
2902         idr_remove(&spi_master_idr, ctlr->bus_num);
2903         mutex_unlock(&board_lock);
2904         return status;
2905 }
2906 EXPORT_SYMBOL_GPL(spi_register_controller);
2907
2908 static void devm_spi_unregister(void *ctlr)
2909 {
2910         spi_unregister_controller(ctlr);
2911 }
2912
2913 /**
2914  * devm_spi_register_controller - register managed SPI master or slave
2915  *      controller
2916  * @dev:    device managing SPI controller
2917  * @ctlr: initialized controller, originally from spi_alloc_master() or
2918  *      spi_alloc_slave()
2919  * Context: can sleep
2920  *
2921  * Register a SPI device as with spi_register_controller() which will
2922  * automatically be unregistered and freed.
2923  *
2924  * Return: zero on success, else a negative error code.
2925  */
2926 int devm_spi_register_controller(struct device *dev,
2927                                  struct spi_controller *ctlr)
2928 {
2929         int ret;
2930
2931         ret = spi_register_controller(ctlr);
2932         if (ret)
2933                 return ret;
2934
2935         return devm_add_action_or_reset(dev, devm_spi_unregister, ctlr);
2936 }
2937 EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2938
2939 static int __unregister(struct device *dev, void *null)
2940 {
2941         spi_unregister_device(to_spi_device(dev));
2942         return 0;
2943 }
2944
2945 /**
2946  * spi_unregister_controller - unregister SPI master or slave controller
2947  * @ctlr: the controller being unregistered
2948  * Context: can sleep
2949  *
2950  * This call is used only by SPI controller drivers, which are the
2951  * only ones directly touching chip registers.
2952  *
2953  * This must be called from context that can sleep.
2954  *
2955  * Note that this function also drops a reference to the controller.
2956  */
2957 void spi_unregister_controller(struct spi_controller *ctlr)
2958 {
2959         struct spi_controller *found;
2960         int id = ctlr->bus_num;
2961
2962         /* Prevent addition of new devices, unregister existing ones */
2963         if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2964                 mutex_lock(&ctlr->add_lock);
2965
2966         device_for_each_child(&ctlr->dev, NULL, __unregister);
2967
2968         /* First make sure that this controller was ever added */
2969         mutex_lock(&board_lock);
2970         found = idr_find(&spi_master_idr, id);
2971         mutex_unlock(&board_lock);
2972         if (ctlr->queued) {
2973                 if (spi_destroy_queue(ctlr))
2974                         dev_err(&ctlr->dev, "queue remove failed\n");
2975         }
2976         mutex_lock(&board_lock);
2977         list_del(&ctlr->list);
2978         mutex_unlock(&board_lock);
2979
2980         device_del(&ctlr->dev);
2981
2982         /* Release the last reference on the controller if its driver
2983          * has not yet been converted to devm_spi_alloc_master/slave().
2984          */
2985         if (!ctlr->devm_allocated)
2986                 put_device(&ctlr->dev);
2987
2988         /* free bus id */
2989         mutex_lock(&board_lock);
2990         if (found == ctlr)
2991                 idr_remove(&spi_master_idr, id);
2992         mutex_unlock(&board_lock);
2993
2994         if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2995                 mutex_unlock(&ctlr->add_lock);
2996 }
2997 EXPORT_SYMBOL_GPL(spi_unregister_controller);
2998
2999 int spi_controller_suspend(struct spi_controller *ctlr)
3000 {
3001         int ret;
3002
3003         /* Basically no-ops for non-queued controllers */
3004         if (!ctlr->queued)
3005                 return 0;
3006
3007         ret = spi_stop_queue(ctlr);
3008         if (ret)
3009                 dev_err(&ctlr->dev, "queue stop failed\n");
3010
3011         return ret;
3012 }
3013 EXPORT_SYMBOL_GPL(spi_controller_suspend);
3014
3015 int spi_controller_resume(struct spi_controller *ctlr)
3016 {
3017         int ret;
3018
3019         if (!ctlr->queued)
3020                 return 0;
3021
3022         ret = spi_start_queue(ctlr);
3023         if (ret)
3024                 dev_err(&ctlr->dev, "queue restart failed\n");
3025
3026         return ret;
3027 }
3028 EXPORT_SYMBOL_GPL(spi_controller_resume);
3029
3030 static int __spi_controller_match(struct device *dev, const void *data)
3031 {
3032         struct spi_controller *ctlr;
3033         const u16 *bus_num = data;
3034
3035         ctlr = container_of(dev, struct spi_controller, dev);
3036         return ctlr->bus_num == *bus_num;
3037 }
3038
3039 /**
3040  * spi_busnum_to_master - look up master associated with bus_num
3041  * @bus_num: the master's bus number
3042  * Context: can sleep
3043  *
3044  * This call may be used with devices that are registered after
3045  * arch init time.  It returns a refcounted pointer to the relevant
3046  * spi_controller (which the caller must release), or NULL if there is
3047  * no such master registered.
3048  *
3049  * Return: the SPI master structure on success, else NULL.
3050  */
3051 struct spi_controller *spi_busnum_to_master(u16 bus_num)
3052 {
3053         struct device           *dev;
3054         struct spi_controller   *ctlr = NULL;
3055
3056         dev = class_find_device(&spi_master_class, NULL, &bus_num,
3057                                 __spi_controller_match);
3058         if (dev)
3059                 ctlr = container_of(dev, struct spi_controller, dev);
3060         /* reference got in class_find_device */
3061         return ctlr;
3062 }
3063 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
3064
3065 /*-------------------------------------------------------------------------*/
3066
3067 /* Core methods for SPI resource management */
3068
3069 /**
3070  * spi_res_alloc - allocate a spi resource that is life-cycle managed
3071  *                 during the processing of a spi_message while using
3072  *                 spi_transfer_one
3073  * @spi:     the spi device for which we allocate memory
3074  * @release: the release code to execute for this resource
3075  * @size:    size to alloc and return
3076  * @gfp:     GFP allocation flags
3077  *
3078  * Return: the pointer to the allocated data
3079  *
3080  * This may get enhanced in the future to allocate from a memory pool
3081  * of the @spi_device or @spi_controller to avoid repeated allocations.
3082  */
3083 void *spi_res_alloc(struct spi_device *spi,
3084                     spi_res_release_t release,
3085                     size_t size, gfp_t gfp)
3086 {
3087         struct spi_res *sres;
3088
3089         sres = kzalloc(sizeof(*sres) + size, gfp);
3090         if (!sres)
3091                 return NULL;
3092
3093         INIT_LIST_HEAD(&sres->entry);
3094         sres->release = release;
3095
3096         return sres->data;
3097 }
3098 EXPORT_SYMBOL_GPL(spi_res_alloc);
3099
3100 /**
3101  * spi_res_free - free an spi resource
3102  * @res: pointer to the custom data of a resource
3103  *
3104  */
3105 void spi_res_free(void *res)
3106 {
3107         struct spi_res *sres = container_of(res, struct spi_res, data);
3108
3109         if (!res)
3110                 return;
3111
3112         WARN_ON(!list_empty(&sres->entry));
3113         kfree(sres);
3114 }
3115 EXPORT_SYMBOL_GPL(spi_res_free);
3116
3117 /**
3118  * spi_res_add - add a spi_res to the spi_message
3119  * @message: the spi message
3120  * @res:     the spi_resource
3121  */
3122 void spi_res_add(struct spi_message *message, void *res)
3123 {
3124         struct spi_res *sres = container_of(res, struct spi_res, data);
3125
3126         WARN_ON(!list_empty(&sres->entry));
3127         list_add_tail(&sres->entry, &message->resources);
3128 }
3129 EXPORT_SYMBOL_GPL(spi_res_add);
3130
3131 /**
3132  * spi_res_release - release all spi resources for this message
3133  * @ctlr:  the @spi_controller
3134  * @message: the @spi_message
3135  */
3136 void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
3137 {
3138         struct spi_res *res, *tmp;
3139
3140         list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
3141                 if (res->release)
3142                         res->release(ctlr, message, res->data);
3143
3144                 list_del(&res->entry);
3145
3146                 kfree(res);
3147         }
3148 }
3149 EXPORT_SYMBOL_GPL(spi_res_release);
3150
3151 /*-------------------------------------------------------------------------*/
3152
3153 /* Core methods for spi_message alterations */
3154
3155 static void __spi_replace_transfers_release(struct spi_controller *ctlr,
3156                                             struct spi_message *msg,
3157                                             void *res)
3158 {
3159         struct spi_replaced_transfers *rxfer = res;
3160         size_t i;
3161
3162         /* call extra callback if requested */
3163         if (rxfer->release)
3164                 rxfer->release(ctlr, msg, res);
3165
3166         /* insert replaced transfers back into the message */
3167         list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
3168
3169         /* remove the formerly inserted entries */
3170         for (i = 0; i < rxfer->inserted; i++)
3171                 list_del(&rxfer->inserted_transfers[i].transfer_list);
3172 }
3173
3174 /**
3175  * spi_replace_transfers - replace transfers with several transfers
3176  *                         and register change with spi_message.resources
3177  * @msg:           the spi_message we work upon
3178  * @xfer_first:    the first spi_transfer we want to replace
3179  * @remove:        number of transfers to remove
3180  * @insert:        the number of transfers we want to insert instead
3181  * @release:       extra release code necessary in some circumstances
3182  * @extradatasize: extra data to allocate (with alignment guarantees
3183  *                 of struct @spi_transfer)
3184  * @gfp:           gfp flags
3185  *
3186  * Returns: pointer to @spi_replaced_transfers,
3187  *          PTR_ERR(...) in case of errors.
3188  */
3189 struct spi_replaced_transfers *spi_replace_transfers(
3190         struct spi_message *msg,
3191         struct spi_transfer *xfer_first,
3192         size_t remove,
3193         size_t insert,
3194         spi_replaced_release_t release,
3195         size_t extradatasize,
3196         gfp_t gfp)
3197 {
3198         struct spi_replaced_transfers *rxfer;
3199         struct spi_transfer *xfer;
3200         size_t i;
3201
3202         /* allocate the structure using spi_res */
3203         rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
3204                               struct_size(rxfer, inserted_transfers, insert)
3205                               + extradatasize,
3206                               gfp);
3207         if (!rxfer)
3208                 return ERR_PTR(-ENOMEM);
3209
3210         /* the release code to invoke before running the generic release */
3211         rxfer->release = release;
3212
3213         /* assign extradata */
3214         if (extradatasize)
3215                 rxfer->extradata =
3216                         &rxfer->inserted_transfers[insert];
3217
3218         /* init the replaced_transfers list */
3219         INIT_LIST_HEAD(&rxfer->replaced_transfers);
3220
3221         /* assign the list_entry after which we should reinsert
3222          * the @replaced_transfers - it may be spi_message.messages!
3223          */
3224         rxfer->replaced_after = xfer_first->transfer_list.prev;
3225
3226         /* remove the requested number of transfers */
3227         for (i = 0; i < remove; i++) {
3228                 /* if the entry after replaced_after it is msg->transfers
3229                  * then we have been requested to remove more transfers
3230                  * than are in the list
3231                  */
3232                 if (rxfer->replaced_after->next == &msg->transfers) {
3233                         dev_err(&msg->spi->dev,
3234                                 "requested to remove more spi_transfers than are available\n");
3235                         /* insert replaced transfers back into the message */
3236                         list_splice(&rxfer->replaced_transfers,
3237                                     rxfer->replaced_after);
3238
3239                         /* free the spi_replace_transfer structure */
3240                         spi_res_free(rxfer);
3241
3242                         /* and return with an error */
3243                         return ERR_PTR(-EINVAL);
3244                 }
3245
3246                 /* remove the entry after replaced_after from list of
3247                  * transfers and add it to list of replaced_transfers
3248                  */
3249                 list_move_tail(rxfer->replaced_after->next,
3250                                &rxfer->replaced_transfers);
3251         }
3252
3253         /* create copy of the given xfer with identical settings
3254          * based on the first transfer to get removed
3255          */
3256         for (i = 0; i < insert; i++) {
3257                 /* we need to run in reverse order */
3258                 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3259
3260                 /* copy all spi_transfer data */
3261                 memcpy(xfer, xfer_first, sizeof(*xfer));
3262
3263                 /* add to list */
3264                 list_add(&xfer->transfer_list, rxfer->replaced_after);
3265
3266                 /* clear cs_change and delay for all but the last */
3267                 if (i) {
3268                         xfer->cs_change = false;
3269                         xfer->delay.value = 0;
3270                 }
3271         }
3272
3273         /* set up inserted */
3274         rxfer->inserted = insert;
3275
3276         /* and register it with spi_res/spi_message */
3277         spi_res_add(msg, rxfer);
3278
3279         return rxfer;
3280 }
3281 EXPORT_SYMBOL_GPL(spi_replace_transfers);
3282
3283 static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3284                                         struct spi_message *msg,
3285                                         struct spi_transfer **xferp,
3286                                         size_t maxsize,
3287                                         gfp_t gfp)
3288 {
3289         struct spi_transfer *xfer = *xferp, *xfers;
3290         struct spi_replaced_transfers *srt;
3291         size_t offset;
3292         size_t count, i;
3293
3294         /* calculate how many we have to replace */
3295         count = DIV_ROUND_UP(xfer->len, maxsize);
3296
3297         /* create replacement */
3298         srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
3299         if (IS_ERR(srt))
3300                 return PTR_ERR(srt);
3301         xfers = srt->inserted_transfers;
3302
3303         /* now handle each of those newly inserted spi_transfers
3304          * note that the replacements spi_transfers all are preset
3305          * to the same values as *xferp, so tx_buf, rx_buf and len
3306          * are all identical (as well as most others)
3307          * so we just have to fix up len and the pointers.
3308          *
3309          * this also includes support for the depreciated
3310          * spi_message.is_dma_mapped interface
3311          */
3312
3313         /* the first transfer just needs the length modified, so we
3314          * run it outside the loop
3315          */
3316         xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3317
3318         /* all the others need rx_buf/tx_buf also set */
3319         for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3320                 /* update rx_buf, tx_buf and dma */
3321                 if (xfers[i].rx_buf)
3322                         xfers[i].rx_buf += offset;
3323                 if (xfers[i].rx_dma)
3324                         xfers[i].rx_dma += offset;
3325                 if (xfers[i].tx_buf)
3326                         xfers[i].tx_buf += offset;
3327                 if (xfers[i].tx_dma)
3328                         xfers[i].tx_dma += offset;
3329
3330                 /* update length */
3331                 xfers[i].len = min(maxsize, xfers[i].len - offset);
3332         }
3333
3334         /* we set up xferp to the last entry we have inserted,
3335          * so that we skip those already split transfers
3336          */
3337         *xferp = &xfers[count - 1];
3338
3339         /* increment statistics counters */
3340         SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3341                                        transfers_split_maxsize);
3342         SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
3343                                        transfers_split_maxsize);
3344
3345         return 0;
3346 }
3347
3348 /**
3349  * spi_split_transfers_maxsize - split spi transfers into multiple transfers
3350  *                               when an individual transfer exceeds a
3351  *                               certain size
3352  * @ctlr:    the @spi_controller for this transfer
3353  * @msg:   the @spi_message to transform
3354  * @maxsize:  the maximum when to apply this
3355  * @gfp: GFP allocation flags
3356  *
3357  * Return: status of transformation
3358  */
3359 int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3360                                 struct spi_message *msg,
3361                                 size_t maxsize,
3362                                 gfp_t gfp)
3363 {
3364         struct spi_transfer *xfer;
3365         int ret;
3366
3367         /* iterate over the transfer_list,
3368          * but note that xfer is advanced to the last transfer inserted
3369          * to avoid checking sizes again unnecessarily (also xfer does
3370          * potentiall belong to a different list by the time the
3371          * replacement has happened
3372          */
3373         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3374                 if (xfer->len > maxsize) {
3375                         ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3376                                                            maxsize, gfp);
3377                         if (ret)
3378                                 return ret;
3379                 }
3380         }
3381
3382         return 0;
3383 }
3384 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3385
3386 /*-------------------------------------------------------------------------*/
3387
3388 /* Core methods for SPI controller protocol drivers.  Some of the
3389  * other core methods are currently defined as inline functions.
3390  */
3391
3392 static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3393                                         u8 bits_per_word)
3394 {
3395         if (ctlr->bits_per_word_mask) {
3396                 /* Only 32 bits fit in the mask */
3397                 if (bits_per_word > 32)
3398                         return -EINVAL;
3399                 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3400                         return -EINVAL;
3401         }
3402
3403         return 0;
3404 }
3405
3406 /**
3407  * spi_setup - setup SPI mode and clock rate
3408  * @spi: the device whose settings are being modified
3409  * Context: can sleep, and no requests are queued to the device
3410  *
3411  * SPI protocol drivers may need to update the transfer mode if the
3412  * device doesn't work with its default.  They may likewise need
3413  * to update clock rates or word sizes from initial values.  This function
3414  * changes those settings, and must be called from a context that can sleep.
3415  * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3416  * effect the next time the device is selected and data is transferred to
3417  * or from it.  When this function returns, the spi device is deselected.
3418  *
3419  * Note that this call will fail if the protocol driver specifies an option
3420  * that the underlying controller or its driver does not support.  For
3421  * example, not all hardware supports wire transfers using nine bit words,
3422  * LSB-first wire encoding, or active-high chipselects.
3423  *
3424  * Return: zero on success, else a negative error code.
3425  */
3426 int spi_setup(struct spi_device *spi)
3427 {
3428         unsigned        bad_bits, ugly_bits;
3429         int             status;
3430
3431         /*
3432          * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
3433          * are set at the same time
3434          */
3435         if ((hweight_long(spi->mode &
3436                 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
3437             (hweight_long(spi->mode &
3438                 (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
3439                 dev_err(&spi->dev,
3440                 "setup: can not select any two of dual, quad and no-rx/tx at the same time\n");
3441                 return -EINVAL;
3442         }
3443         /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
3444          */
3445         if ((spi->mode & SPI_3WIRE) && (spi->mode &
3446                 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3447                  SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3448                 return -EINVAL;
3449         /* help drivers fail *cleanly* when they need options
3450          * that aren't supported with their current controller
3451          * SPI_CS_WORD has a fallback software implementation,
3452          * so it is ignored here.
3453          */
3454         bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
3455                                  SPI_NO_TX | SPI_NO_RX);
3456         /* nothing prevents from working with active-high CS in case if it
3457          * is driven by GPIO.
3458          */
3459         if (gpio_is_valid(spi->cs_gpio))
3460                 bad_bits &= ~SPI_CS_HIGH;
3461         ugly_bits = bad_bits &
3462                     (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3463                      SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3464         if (ugly_bits) {
3465                 dev_warn(&spi->dev,
3466                          "setup: ignoring unsupported mode bits %x\n",
3467                          ugly_bits);
3468                 spi->mode &= ~ugly_bits;
3469                 bad_bits &= ~ugly_bits;
3470         }
3471         if (bad_bits) {
3472                 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3473                         bad_bits);
3474                 return -EINVAL;
3475         }
3476
3477         if (!spi->bits_per_word)
3478                 spi->bits_per_word = 8;
3479
3480         status = __spi_validate_bits_per_word(spi->controller,
3481                                               spi->bits_per_word);
3482         if (status)
3483                 return status;
3484
3485         if (spi->controller->max_speed_hz &&
3486             (!spi->max_speed_hz ||
3487              spi->max_speed_hz > spi->controller->max_speed_hz))
3488                 spi->max_speed_hz = spi->controller->max_speed_hz;
3489
3490         mutex_lock(&spi->controller->io_mutex);
3491
3492         if (spi->controller->setup) {
3493                 status = spi->controller->setup(spi);
3494                 if (status) {
3495                         mutex_unlock(&spi->controller->io_mutex);
3496                         dev_err(&spi->controller->dev, "Failed to setup device: %d\n",
3497                                 status);
3498                         return status;
3499                 }
3500         }
3501
3502         if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
3503                 status = pm_runtime_get_sync(spi->controller->dev.parent);
3504                 if (status < 0) {
3505                         mutex_unlock(&spi->controller->io_mutex);
3506                         pm_runtime_put_noidle(spi->controller->dev.parent);
3507                         dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3508                                 status);
3509                         return status;
3510                 }
3511
3512                 /*
3513                  * We do not want to return positive value from pm_runtime_get,
3514                  * there are many instances of devices calling spi_setup() and
3515                  * checking for a non-zero return value instead of a negative
3516                  * return value.
3517                  */
3518                 status = 0;
3519
3520                 spi_set_cs(spi, false, true);
3521                 pm_runtime_mark_last_busy(spi->controller->dev.parent);
3522                 pm_runtime_put_autosuspend(spi->controller->dev.parent);
3523         } else {
3524                 spi_set_cs(spi, false, true);
3525         }
3526
3527         mutex_unlock(&spi->controller->io_mutex);
3528
3529         if (spi->rt && !spi->controller->rt) {
3530                 spi->controller->rt = true;
3531                 spi_set_thread_rt(spi->controller);
3532         }
3533
3534         trace_spi_setup(spi, status);
3535
3536         dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3537                         spi->mode & SPI_MODE_X_MASK,
3538                         (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
3539                         (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
3540                         (spi->mode & SPI_3WIRE) ? "3wire, " : "",
3541                         (spi->mode & SPI_LOOP) ? "loopback, " : "",
3542                         spi->bits_per_word, spi->max_speed_hz,
3543                         status);
3544
3545         return status;
3546 }
3547 EXPORT_SYMBOL_GPL(spi_setup);
3548
3549 static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
3550                                        struct spi_device *spi)
3551 {
3552         int delay1, delay2;
3553
3554         delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
3555         if (delay1 < 0)
3556                 return delay1;
3557
3558         delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
3559         if (delay2 < 0)
3560                 return delay2;
3561
3562         if (delay1 < delay2)
3563                 memcpy(&xfer->word_delay, &spi->word_delay,
3564                        sizeof(xfer->word_delay));
3565
3566         return 0;
3567 }
3568
3569 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
3570 {
3571         struct spi_controller *ctlr = spi->controller;
3572         struct spi_transfer *xfer;
3573         int w_size;
3574
3575         if (list_empty(&message->transfers))
3576                 return -EINVAL;
3577
3578         /* If an SPI controller does not support toggling the CS line on each
3579          * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3580          * for the CS line, we can emulate the CS-per-word hardware function by
3581          * splitting transfers into one-word transfers and ensuring that
3582          * cs_change is set for each transfer.
3583          */
3584         if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
3585                                           spi->cs_gpiod ||
3586                                           gpio_is_valid(spi->cs_gpio))) {
3587                 size_t maxsize;
3588                 int ret;
3589
3590                 maxsize = (spi->bits_per_word + 7) / 8;
3591
3592                 /* spi_split_transfers_maxsize() requires message->spi */
3593                 message->spi = spi;
3594
3595                 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
3596                                                   GFP_KERNEL);
3597                 if (ret)
3598                         return ret;
3599
3600                 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3601                         /* don't change cs_change on the last entry in the list */
3602                         if (list_is_last(&xfer->transfer_list, &message->transfers))
3603                                 break;
3604                         xfer->cs_change = 1;
3605                 }
3606         }
3607
3608         /* Half-duplex links include original MicroWire, and ones with
3609          * only one data pin like SPI_3WIRE (switches direction) or where
3610          * either MOSI or MISO is missing.  They can also be caused by
3611          * software limitations.
3612          */
3613         if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
3614             (spi->mode & SPI_3WIRE)) {
3615                 unsigned flags = ctlr->flags;
3616
3617                 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3618                         if (xfer->rx_buf && xfer->tx_buf)
3619                                 return -EINVAL;
3620                         if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
3621                                 return -EINVAL;
3622                         if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
3623                                 return -EINVAL;
3624                 }
3625         }
3626
3627         /**
3628          * Set transfer bits_per_word and max speed as spi device default if
3629          * it is not set for this transfer.
3630          * Set transfer tx_nbits and rx_nbits as single transfer default
3631          * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3632          * Ensure transfer word_delay is at least as long as that required by
3633          * device itself.
3634          */
3635         message->frame_length = 0;
3636         list_for_each_entry(xfer, &message->transfers, transfer_list) {
3637                 xfer->effective_speed_hz = 0;
3638                 message->frame_length += xfer->len;
3639                 if (!xfer->bits_per_word)
3640                         xfer->bits_per_word = spi->bits_per_word;
3641
3642                 if (!xfer->speed_hz)
3643                         xfer->speed_hz = spi->max_speed_hz;
3644
3645                 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
3646                         xfer->speed_hz = ctlr->max_speed_hz;
3647
3648                 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
3649                         return -EINVAL;
3650
3651                 /*
3652                  * SPI transfer length should be multiple of SPI word size
3653                  * where SPI word size should be power-of-two multiple
3654                  */
3655                 if (xfer->bits_per_word <= 8)
3656                         w_size = 1;
3657                 else if (xfer->bits_per_word <= 16)
3658                         w_size = 2;
3659                 else
3660                         w_size = 4;
3661
3662                 /* No partial transfers accepted */
3663                 if (xfer->len % w_size)
3664                         return -EINVAL;
3665
3666                 if (xfer->speed_hz && ctlr->min_speed_hz &&
3667                     xfer->speed_hz < ctlr->min_speed_hz)
3668                         return -EINVAL;
3669
3670                 if (xfer->tx_buf && !xfer->tx_nbits)
3671                         xfer->tx_nbits = SPI_NBITS_SINGLE;
3672                 if (xfer->rx_buf && !xfer->rx_nbits)
3673                         xfer->rx_nbits = SPI_NBITS_SINGLE;
3674                 /* check transfer tx/rx_nbits:
3675                  * 1. check the value matches one of single, dual and quad
3676                  * 2. check tx/rx_nbits match the mode in spi_device
3677                  */
3678                 if (xfer->tx_buf) {
3679                         if (spi->mode & SPI_NO_TX)
3680                                 return -EINVAL;
3681                         if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3682                                 xfer->tx_nbits != SPI_NBITS_DUAL &&
3683                                 xfer->tx_nbits != SPI_NBITS_QUAD)
3684                                 return -EINVAL;
3685                         if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3686                                 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3687                                 return -EINVAL;
3688                         if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3689                                 !(spi->mode & SPI_TX_QUAD))
3690                                 return -EINVAL;
3691                 }
3692                 /* check transfer rx_nbits */
3693                 if (xfer->rx_buf) {
3694                         if (spi->mode & SPI_NO_RX)
3695                                 return -EINVAL;
3696                         if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3697                                 xfer->rx_nbits != SPI_NBITS_DUAL &&
3698                                 xfer->rx_nbits != SPI_NBITS_QUAD)
3699                                 return -EINVAL;
3700                         if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3701                                 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3702                                 return -EINVAL;
3703                         if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3704                                 !(spi->mode & SPI_RX_QUAD))
3705                                 return -EINVAL;
3706                 }
3707
3708                 if (_spi_xfer_word_delay_update(xfer, spi))
3709                         return -EINVAL;
3710         }
3711
3712         message->status = -EINPROGRESS;
3713
3714         return 0;
3715 }
3716
3717 static int __spi_async(struct spi_device *spi, struct spi_message *message)
3718 {
3719         struct spi_controller *ctlr = spi->controller;
3720         struct spi_transfer *xfer;
3721
3722         /*
3723          * Some controllers do not support doing regular SPI transfers. Return
3724          * ENOTSUPP when this is the case.
3725          */
3726         if (!ctlr->transfer)
3727                 return -ENOTSUPP;
3728
3729         message->spi = spi;
3730
3731         SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
3732         SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3733
3734         trace_spi_message_submit(message);
3735
3736         if (!ctlr->ptp_sts_supported) {
3737                 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3738                         xfer->ptp_sts_word_pre = 0;
3739                         ptp_read_system_prets(xfer->ptp_sts);
3740                 }
3741         }
3742
3743         return ctlr->transfer(spi, message);
3744 }
3745
3746 /**
3747  * spi_async - asynchronous SPI transfer
3748  * @spi: device with which data will be exchanged
3749  * @message: describes the data transfers, including completion callback
3750  * Context: any (irqs may be blocked, etc)
3751  *
3752  * This call may be used in_irq and other contexts which can't sleep,
3753  * as well as from task contexts which can sleep.
3754  *
3755  * The completion callback is invoked in a context which can't sleep.
3756  * Before that invocation, the value of message->status is undefined.
3757  * When the callback is issued, message->status holds either zero (to
3758  * indicate complete success) or a negative error code.  After that
3759  * callback returns, the driver which issued the transfer request may
3760  * deallocate the associated memory; it's no longer in use by any SPI
3761  * core or controller driver code.
3762  *
3763  * Note that although all messages to a spi_device are handled in
3764  * FIFO order, messages may go to different devices in other orders.
3765  * Some device might be higher priority, or have various "hard" access
3766  * time requirements, for example.
3767  *
3768  * On detection of any fault during the transfer, processing of
3769  * the entire message is aborted, and the device is deselected.
3770  * Until returning from the associated message completion callback,
3771  * no other spi_message queued to that device will be processed.
3772  * (This rule applies equally to all the synchronous transfer calls,
3773  * which are wrappers around this core asynchronous primitive.)
3774  *
3775  * Return: zero on success, else a negative error code.
3776  */
3777 int spi_async(struct spi_device *spi, struct spi_message *message)
3778 {
3779         struct spi_controller *ctlr = spi->controller;
3780         int ret;
3781         unsigned long flags;
3782
3783         ret = __spi_validate(spi, message);
3784         if (ret != 0)
3785                 return ret;
3786
3787         spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3788
3789         if (ctlr->bus_lock_flag)
3790                 ret = -EBUSY;
3791         else
3792                 ret = __spi_async(spi, message);
3793
3794         spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3795
3796         return ret;
3797 }
3798 EXPORT_SYMBOL_GPL(spi_async);
3799
3800 /**
3801  * spi_async_locked - version of spi_async with exclusive bus usage
3802  * @spi: device with which data will be exchanged
3803  * @message: describes the data transfers, including completion callback
3804  * Context: any (irqs may be blocked, etc)
3805  *
3806  * This call may be used in_irq and other contexts which can't sleep,
3807  * as well as from task contexts which can sleep.
3808  *
3809  * The completion callback is invoked in a context which can't sleep.
3810  * Before that invocation, the value of message->status is undefined.
3811  * When the callback is issued, message->status holds either zero (to
3812  * indicate complete success) or a negative error code.  After that
3813  * callback returns, the driver which issued the transfer request may
3814  * deallocate the associated memory; it's no longer in use by any SPI
3815  * core or controller driver code.
3816  *
3817  * Note that although all messages to a spi_device are handled in
3818  * FIFO order, messages may go to different devices in other orders.
3819  * Some device might be higher priority, or have various "hard" access
3820  * time requirements, for example.
3821  *
3822  * On detection of any fault during the transfer, processing of
3823  * the entire message is aborted, and the device is deselected.
3824  * Until returning from the associated message completion callback,
3825  * no other spi_message queued to that device will be processed.
3826  * (This rule applies equally to all the synchronous transfer calls,
3827  * which are wrappers around this core asynchronous primitive.)
3828  *
3829  * Return: zero on success, else a negative error code.
3830  */
3831 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3832 {
3833         struct spi_controller *ctlr = spi->controller;
3834         int ret;
3835         unsigned long flags;
3836
3837         ret = __spi_validate(spi, message);
3838         if (ret != 0)
3839                 return ret;
3840
3841         spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3842
3843         ret = __spi_async(spi, message);
3844
3845         spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3846
3847         return ret;
3848
3849 }
3850 EXPORT_SYMBOL_GPL(spi_async_locked);
3851
3852 /*-------------------------------------------------------------------------*/
3853
3854 /* Utility methods for SPI protocol drivers, layered on
3855  * top of the core.  Some other utility methods are defined as
3856  * inline functions.
3857  */
3858
3859 static void spi_complete(void *arg)
3860 {
3861         complete(arg);
3862 }
3863
3864 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3865 {
3866         DECLARE_COMPLETION_ONSTACK(done);
3867         int status;
3868         struct spi_controller *ctlr = spi->controller;
3869         unsigned long flags;
3870
3871         status = __spi_validate(spi, message);
3872         if (status != 0)
3873                 return status;
3874
3875         message->complete = spi_complete;
3876         message->context = &done;
3877         message->spi = spi;
3878
3879         SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3880         SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3881
3882         /* If we're not using the legacy transfer method then we will
3883          * try to transfer in the calling context so special case.
3884          * This code would be less tricky if we could remove the
3885          * support for driver implemented message queues.
3886          */
3887         if (ctlr->transfer == spi_queued_transfer) {
3888                 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3889
3890                 trace_spi_message_submit(message);
3891
3892                 status = __spi_queued_transfer(spi, message, false);
3893
3894                 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3895         } else {
3896                 status = spi_async_locked(spi, message);
3897         }
3898
3899         if (status == 0) {
3900                 /* Push out the messages in the calling context if we
3901                  * can.
3902                  */
3903                 if (ctlr->transfer == spi_queued_transfer) {
3904                         SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3905                                                        spi_sync_immediate);
3906                         SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3907                                                        spi_sync_immediate);
3908                         __spi_pump_messages(ctlr, false);
3909                 }
3910
3911                 wait_for_completion(&done);
3912                 status = message->status;
3913         }
3914         message->context = NULL;
3915         return status;
3916 }
3917
3918 /**
3919  * spi_sync - blocking/synchronous SPI data transfers
3920  * @spi: device with which data will be exchanged
3921  * @message: describes the data transfers
3922  * Context: can sleep
3923  *
3924  * This call may only be used from a context that may sleep.  The sleep
3925  * is non-interruptible, and has no timeout.  Low-overhead controller
3926  * drivers may DMA directly into and out of the message buffers.
3927  *
3928  * Note that the SPI device's chip select is active during the message,
3929  * and then is normally disabled between messages.  Drivers for some
3930  * frequently-used devices may want to minimize costs of selecting a chip,
3931  * by leaving it selected in anticipation that the next message will go
3932  * to the same chip.  (That may increase power usage.)
3933  *
3934  * Also, the caller is guaranteeing that the memory associated with the
3935  * message will not be freed before this call returns.
3936  *
3937  * Return: zero on success, else a negative error code.
3938  */
3939 int spi_sync(struct spi_device *spi, struct spi_message *message)
3940 {
3941         int ret;
3942
3943         mutex_lock(&spi->controller->bus_lock_mutex);
3944         ret = __spi_sync(spi, message);
3945         mutex_unlock(&spi->controller->bus_lock_mutex);
3946
3947         return ret;
3948 }
3949 EXPORT_SYMBOL_GPL(spi_sync);
3950
3951 /**
3952  * spi_sync_locked - version of spi_sync with exclusive bus usage
3953  * @spi: device with which data will be exchanged
3954  * @message: describes the data transfers
3955  * Context: can sleep
3956  *
3957  * This call may only be used from a context that may sleep.  The sleep
3958  * is non-interruptible, and has no timeout.  Low-overhead controller
3959  * drivers may DMA directly into and out of the message buffers.
3960  *
3961  * This call should be used by drivers that require exclusive access to the
3962  * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3963  * be released by a spi_bus_unlock call when the exclusive access is over.
3964  *
3965  * Return: zero on success, else a negative error code.
3966  */
3967 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3968 {
3969         return __spi_sync(spi, message);
3970 }
3971 EXPORT_SYMBOL_GPL(spi_sync_locked);
3972
3973 /**
3974  * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3975  * @ctlr: SPI bus master that should be locked for exclusive bus access
3976  * Context: can sleep
3977  *
3978  * This call may only be used from a context that may sleep.  The sleep
3979  * is non-interruptible, and has no timeout.
3980  *
3981  * This call should be used by drivers that require exclusive access to the
3982  * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3983  * exclusive access is over. Data transfer must be done by spi_sync_locked
3984  * and spi_async_locked calls when the SPI bus lock is held.
3985  *
3986  * Return: always zero.
3987  */
3988 int spi_bus_lock(struct spi_controller *ctlr)
3989 {
3990         unsigned long flags;
3991
3992         mutex_lock(&ctlr->bus_lock_mutex);
3993
3994         spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3995         ctlr->bus_lock_flag = 1;
3996         spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3997
3998         /* mutex remains locked until spi_bus_unlock is called */
3999
4000         return 0;
4001 }
4002 EXPORT_SYMBOL_GPL(spi_bus_lock);
4003
4004 /**
4005  * spi_bus_unlock - release the lock for exclusive SPI bus usage
4006  * @ctlr: SPI bus master that was locked for exclusive bus access
4007  * Context: can sleep
4008  *
4009  * This call may only be used from a context that may sleep.  The sleep
4010  * is non-interruptible, and has no timeout.
4011  *
4012  * This call releases an SPI bus lock previously obtained by an spi_bus_lock
4013  * call.
4014  *
4015  * Return: always zero.
4016  */
4017 int spi_bus_unlock(struct spi_controller *ctlr)
4018 {
4019         ctlr->bus_lock_flag = 0;
4020
4021         mutex_unlock(&ctlr->bus_lock_mutex);
4022
4023         return 0;
4024 }
4025 EXPORT_SYMBOL_GPL(spi_bus_unlock);
4026
4027 /* portable code must never pass more than 32 bytes */
4028 #define SPI_BUFSIZ      max(32, SMP_CACHE_BYTES)
4029
4030 static u8       *buf;
4031
4032 /**
4033  * spi_write_then_read - SPI synchronous write followed by read
4034  * @spi: device with which data will be exchanged
4035  * @txbuf: data to be written (need not be dma-safe)
4036  * @n_tx: size of txbuf, in bytes
4037  * @rxbuf: buffer into which data will be read (need not be dma-safe)
4038  * @n_rx: size of rxbuf, in bytes
4039  * Context: can sleep
4040  *
4041  * This performs a half duplex MicroWire style transaction with the
4042  * device, sending txbuf and then reading rxbuf.  The return value
4043  * is zero for success, else a negative errno status code.
4044  * This call may only be used from a context that may sleep.
4045  *
4046  * Parameters to this routine are always copied using a small buffer.
4047  * Performance-sensitive or bulk transfer code should instead use
4048  * spi_{async,sync}() calls with dma-safe buffers.
4049  *
4050  * Return: zero on success, else a negative error code.
4051  */
4052 int spi_write_then_read(struct spi_device *spi,
4053                 const void *txbuf, unsigned n_tx,
4054                 void *rxbuf, unsigned n_rx)
4055 {
4056         static DEFINE_MUTEX(lock);
4057
4058         int                     status;
4059         struct spi_message      message;
4060         struct spi_transfer     x[2];
4061         u8                      *local_buf;
4062
4063         /* Use preallocated DMA-safe buffer if we can.  We can't avoid
4064          * copying here, (as a pure convenience thing), but we can
4065          * keep heap costs out of the hot path unless someone else is
4066          * using the pre-allocated buffer or the transfer is too large.
4067          */
4068         if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
4069                 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
4070                                     GFP_KERNEL | GFP_DMA);
4071                 if (!local_buf)
4072                         return -ENOMEM;
4073         } else {
4074                 local_buf = buf;
4075         }
4076
4077         spi_message_init(&message);
4078         memset(x, 0, sizeof(x));
4079         if (n_tx) {
4080                 x[0].len = n_tx;
4081                 spi_message_add_tail(&x[0], &message);
4082         }
4083         if (n_rx) {
4084                 x[1].len = n_rx;
4085                 spi_message_add_tail(&x[1], &message);
4086         }
4087
4088         memcpy(local_buf, txbuf, n_tx);
4089         x[0].tx_buf = local_buf;
4090         x[1].rx_buf = local_buf + n_tx;
4091
4092         /* do the i/o */
4093         status = spi_sync(spi, &message);
4094         if (status == 0)
4095                 memcpy(rxbuf, x[1].rx_buf, n_rx);
4096
4097         if (x[0].tx_buf == buf)
4098                 mutex_unlock(&lock);
4099         else
4100                 kfree(local_buf);
4101
4102         return status;
4103 }
4104 EXPORT_SYMBOL_GPL(spi_write_then_read);
4105
4106 /*-------------------------------------------------------------------------*/
4107
4108 #if IS_ENABLED(CONFIG_OF)
4109 /* must call put_device() when done with returned spi_device device */
4110 struct spi_device *of_find_spi_device_by_node(struct device_node *node)
4111 {
4112         struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
4113
4114         return dev ? to_spi_device(dev) : NULL;
4115 }
4116 EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
4117 #endif /* IS_ENABLED(CONFIG_OF) */
4118
4119 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
4120 /* the spi controllers are not using spi_bus, so we find it with another way */
4121 static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
4122 {
4123         struct device *dev;
4124
4125         dev = class_find_device_by_of_node(&spi_master_class, node);
4126         if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4127                 dev = class_find_device_by_of_node(&spi_slave_class, node);
4128         if (!dev)
4129                 return NULL;
4130
4131         /* reference got in class_find_device */
4132         return container_of(dev, struct spi_controller, dev);
4133 }
4134
4135 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
4136                          void *arg)
4137 {
4138         struct of_reconfig_data *rd = arg;
4139         struct spi_controller *ctlr;
4140         struct spi_device *spi;
4141
4142         switch (of_reconfig_get_state_change(action, arg)) {
4143         case OF_RECONFIG_CHANGE_ADD:
4144                 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
4145                 if (ctlr == NULL)
4146                         return NOTIFY_OK;       /* not for us */
4147
4148                 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
4149                         put_device(&ctlr->dev);
4150                         return NOTIFY_OK;
4151                 }
4152
4153                 spi = of_register_spi_device(ctlr, rd->dn);
4154                 put_device(&ctlr->dev);
4155
4156                 if (IS_ERR(spi)) {
4157                         pr_err("%s: failed to create for '%pOF'\n",
4158                                         __func__, rd->dn);
4159                         of_node_clear_flag(rd->dn, OF_POPULATED);
4160                         return notifier_from_errno(PTR_ERR(spi));
4161                 }
4162                 break;
4163
4164         case OF_RECONFIG_CHANGE_REMOVE:
4165                 /* already depopulated? */
4166                 if (!of_node_check_flag(rd->dn, OF_POPULATED))
4167                         return NOTIFY_OK;
4168
4169                 /* find our device by node */
4170                 spi = of_find_spi_device_by_node(rd->dn);
4171                 if (spi == NULL)
4172                         return NOTIFY_OK;       /* no? not meant for us */
4173
4174                 /* unregister takes one ref away */
4175                 spi_unregister_device(spi);
4176
4177                 /* and put the reference of the find */
4178                 put_device(&spi->dev);
4179                 break;
4180         }
4181
4182         return NOTIFY_OK;
4183 }
4184
4185 static struct notifier_block spi_of_notifier = {
4186         .notifier_call = of_spi_notify,
4187 };
4188 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4189 extern struct notifier_block spi_of_notifier;
4190 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4191
4192 #if IS_ENABLED(CONFIG_ACPI)
4193 static int spi_acpi_controller_match(struct device *dev, const void *data)
4194 {
4195         return ACPI_COMPANION(dev->parent) == data;
4196 }
4197
4198 static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4199 {
4200         struct device *dev;
4201
4202         dev = class_find_device(&spi_master_class, NULL, adev,
4203                                 spi_acpi_controller_match);
4204         if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4205                 dev = class_find_device(&spi_slave_class, NULL, adev,
4206                                         spi_acpi_controller_match);
4207         if (!dev)
4208                 return NULL;
4209
4210         return container_of(dev, struct spi_controller, dev);
4211 }
4212
4213 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4214 {
4215         struct device *dev;
4216
4217         dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4218         return to_spi_device(dev);
4219 }
4220
4221 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4222                            void *arg)
4223 {
4224         struct acpi_device *adev = arg;
4225         struct spi_controller *ctlr;
4226         struct spi_device *spi;
4227
4228         switch (value) {
4229         case ACPI_RECONFIG_DEVICE_ADD:
4230                 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
4231                 if (!ctlr)
4232                         break;
4233
4234                 acpi_register_spi_device(ctlr, adev);
4235                 put_device(&ctlr->dev);
4236                 break;
4237         case ACPI_RECONFIG_DEVICE_REMOVE:
4238                 if (!acpi_device_enumerated(adev))
4239                         break;
4240
4241                 spi = acpi_spi_find_device_by_adev(adev);
4242                 if (!spi)
4243                         break;
4244
4245                 spi_unregister_device(spi);
4246                 put_device(&spi->dev);
4247                 break;
4248         }
4249
4250         return NOTIFY_OK;
4251 }
4252
4253 static struct notifier_block spi_acpi_notifier = {
4254         .notifier_call = acpi_spi_notify,
4255 };
4256 #else
4257 extern struct notifier_block spi_acpi_notifier;
4258 #endif
4259
4260 static int __init spi_init(void)
4261 {
4262         int     status;
4263
4264         buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4265         if (!buf) {
4266                 status = -ENOMEM;
4267                 goto err0;
4268         }
4269
4270         status = bus_register(&spi_bus_type);
4271         if (status < 0)
4272                 goto err1;
4273
4274         status = class_register(&spi_master_class);
4275         if (status < 0)
4276                 goto err2;
4277
4278         if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4279                 status = class_register(&spi_slave_class);
4280                 if (status < 0)
4281                         goto err3;
4282         }
4283
4284         if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4285                 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4286         if (IS_ENABLED(CONFIG_ACPI))
4287                 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4288
4289         return 0;
4290
4291 err3:
4292         class_unregister(&spi_master_class);
4293 err2:
4294         bus_unregister(&spi_bus_type);
4295 err1:
4296         kfree(buf);
4297         buf = NULL;
4298 err0:
4299         return status;
4300 }
4301
4302 /* board_info is normally registered in arch_initcall(),
4303  * but even essential drivers wait till later
4304  *
4305  * REVISIT only boardinfo really needs static linking. the rest (device and
4306  * driver registration) _could_ be dynamically linked (modular) ... costs
4307  * include needing to have boardinfo data structures be much more public.
4308  */
4309 postcore_initcall(spi_init);