1 // SPDX-License-Identifier: GPL-2.0-or-later
4 // Copyright (C) 2005 David Brownell
5 // Copyright (C) 2008 Secret Lab Technologies Ltd.
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>
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);
42 #include "internals.h"
44 static DEFINE_IDR(spi_master_idr);
46 static void spidev_release(struct device *dev)
48 struct spi_device *spi = to_spi_device(dev);
50 spi_controller_put(spi->controller);
51 kfree(spi->driver_override);
56 modalias_show(struct device *dev, struct device_attribute *a, char *buf)
58 const struct spi_device *spi = to_spi_device(dev);
61 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
65 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
67 static DEVICE_ATTR_RO(modalias);
69 static ssize_t driver_override_store(struct device *dev,
70 struct device_attribute *a,
71 const char *buf, size_t count)
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;
78 /* We need to keep extra room for a newline when displaying value */
79 if (len >= (PAGE_SIZE - 1))
82 driver_override = kstrndup(buf, len, GFP_KERNEL);
87 old = spi->driver_override;
89 spi->driver_override = driver_override;
91 /* Empty string, disable driver override */
92 spi->driver_override = NULL;
93 kfree(driver_override);
101 static ssize_t driver_override_show(struct device *dev,
102 struct device_attribute *a, char *buf)
104 const struct spi_device *spi = to_spi_device(dev);
108 len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
112 static DEVICE_ATTR_RW(driver_override);
114 #define SPI_STATISTICS_ATTRS(field, file) \
115 static ssize_t spi_controller_##field##_show(struct device *dev, \
116 struct device_attribute *attr, \
119 struct spi_controller *ctlr = container_of(dev, \
120 struct spi_controller, dev); \
121 return spi_statistics_##field##_show(&ctlr->statistics, buf); \
123 static struct device_attribute dev_attr_spi_controller_##field = { \
124 .attr = { .name = file, .mode = 0444 }, \
125 .show = spi_controller_##field##_show, \
127 static ssize_t spi_device_##field##_show(struct device *dev, \
128 struct device_attribute *attr, \
131 struct spi_device *spi = to_spi_device(dev); \
132 return spi_statistics_##field##_show(&spi->statistics, buf); \
134 static struct device_attribute dev_attr_spi_device_##field = { \
135 .attr = { .name = file, .mode = 0444 }, \
136 .show = spi_device_##field##_show, \
139 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
140 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
143 unsigned long flags; \
145 spin_lock_irqsave(&stat->lock, flags); \
146 len = sprintf(buf, format_string, stat->field); \
147 spin_unlock_irqrestore(&stat->lock, flags); \
150 SPI_STATISTICS_ATTRS(name, file)
152 #define SPI_STATISTICS_SHOW(field, format_string) \
153 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
154 field, format_string)
156 SPI_STATISTICS_SHOW(messages, "%lu");
157 SPI_STATISTICS_SHOW(transfers, "%lu");
158 SPI_STATISTICS_SHOW(errors, "%lu");
159 SPI_STATISTICS_SHOW(timedout, "%lu");
161 SPI_STATISTICS_SHOW(spi_sync, "%lu");
162 SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
163 SPI_STATISTICS_SHOW(spi_async, "%lu");
165 SPI_STATISTICS_SHOW(bytes, "%llu");
166 SPI_STATISTICS_SHOW(bytes_rx, "%llu");
167 SPI_STATISTICS_SHOW(bytes_tx, "%llu");
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+");
191 SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
193 static struct attribute *spi_dev_attrs[] = {
194 &dev_attr_modalias.attr,
195 &dev_attr_driver_override.attr,
199 static const struct attribute_group spi_dev_group = {
200 .attrs = spi_dev_attrs,
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,
235 static const struct attribute_group spi_device_statistics_group = {
236 .name = "statistics",
237 .attrs = spi_device_statistics_attrs,
240 static const struct attribute_group *spi_dev_groups[] = {
242 &spi_device_statistics_group,
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,
278 static const struct attribute_group spi_controller_statistics_group = {
279 .name = "statistics",
280 .attrs = spi_controller_statistics_attrs,
283 static const struct attribute_group *spi_master_groups[] = {
284 &spi_controller_statistics_group,
288 void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
289 struct spi_transfer *xfer,
290 struct spi_controller *ctlr)
293 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
298 spin_lock_irqsave(&stats->lock, flags);
301 stats->transfer_bytes_histo[l2len]++;
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;
311 spin_unlock_irqrestore(&stats->lock, flags);
313 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
315 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
316 * and the sysfs version makes coldplug work too.
319 static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
320 const struct spi_device *sdev)
322 while (id->name[0]) {
323 if (!strcmp(sdev->modalias, id->name))
330 const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
332 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
334 return spi_match_id(sdrv->id_table, sdev);
336 EXPORT_SYMBOL_GPL(spi_get_device_id);
338 static int spi_match_device(struct device *dev, struct device_driver *drv)
340 const struct spi_device *spi = to_spi_device(dev);
341 const struct spi_driver *sdrv = to_spi_driver(drv);
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;
347 /* Attempt an OF style match */
348 if (of_driver_match_device(dev, drv))
352 if (acpi_driver_match_device(dev, drv))
356 return !!spi_match_id(sdrv->id_table, spi);
358 return strcmp(spi->modalias, drv->name) == 0;
361 static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
363 const struct spi_device *spi = to_spi_device(dev);
366 rc = acpi_device_uevent_modalias(dev, env);
370 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
373 static int spi_probe(struct device *dev)
375 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
376 struct spi_device *spi = to_spi_device(dev);
379 ret = of_clk_set_defaults(dev->of_node, false);
384 spi->irq = of_irq_get(dev->of_node, 0);
385 if (spi->irq == -EPROBE_DEFER)
386 return -EPROBE_DEFER;
391 ret = dev_pm_domain_attach(dev, true);
396 ret = sdrv->probe(spi);
398 dev_pm_domain_detach(dev, true);
404 static void spi_remove(struct device *dev)
406 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
411 ret = sdrv->remove(to_spi_device(dev));
414 "Failed to unbind driver (%pe), ignoring\n",
418 dev_pm_domain_detach(dev, true);
421 static void spi_shutdown(struct device *dev)
424 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
427 sdrv->shutdown(to_spi_device(dev));
431 struct bus_type spi_bus_type = {
433 .dev_groups = spi_dev_groups,
434 .match = spi_match_device,
435 .uevent = spi_uevent,
437 .remove = spi_remove,
438 .shutdown = spi_shutdown,
440 EXPORT_SYMBOL_GPL(spi_bus_type);
443 * __spi_register_driver - register a SPI driver
444 * @owner: owner module of the driver to register
445 * @sdrv: the driver to register
448 * Return: zero on success, else a negative error code.
450 int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
452 sdrv->driver.owner = owner;
453 sdrv->driver.bus = &spi_bus_type;
456 * For Really Good Reasons we use spi: modaliases not of:
457 * modaliases for DT so module autoloading won't work if we
458 * don't have a spi_device_id as well as a compatible string.
460 if (sdrv->driver.of_match_table) {
461 const struct of_device_id *of_id;
463 for (of_id = sdrv->driver.of_match_table; of_id->compatible[0];
467 /* Strip off any vendor prefix */
468 of_name = strnchr(of_id->compatible,
469 sizeof(of_id->compatible), ',');
473 of_name = of_id->compatible;
475 if (sdrv->id_table) {
476 const struct spi_device_id *spi_id;
478 for (spi_id = sdrv->id_table; spi_id->name[0];
480 if (strcmp(spi_id->name, of_name) == 0)
486 if (strcmp(sdrv->driver.name, of_name) == 0)
490 pr_warn("SPI driver %s has no spi_device_id for %s\n",
491 sdrv->driver.name, of_id->compatible);
495 return driver_register(&sdrv->driver);
497 EXPORT_SYMBOL_GPL(__spi_register_driver);
499 /*-------------------------------------------------------------------------*/
501 /* SPI devices should normally not be created by SPI device drivers; that
502 * would make them board-specific. Similarly with SPI controller drivers.
503 * Device registration normally goes into like arch/.../mach.../board-YYY.c
504 * with other readonly (flashable) information about mainboard devices.
508 struct list_head list;
509 struct spi_board_info board_info;
512 static LIST_HEAD(board_list);
513 static LIST_HEAD(spi_controller_list);
516 * Used to protect add/del operation for board_info list and
517 * spi_controller list, and their matching process
518 * also used to protect object of type struct idr
520 static DEFINE_MUTEX(board_lock);
523 * spi_alloc_device - Allocate a new SPI device
524 * @ctlr: Controller to which device is connected
527 * Allows a driver to allocate and initialize a spi_device without
528 * registering it immediately. This allows a driver to directly
529 * fill the spi_device with device parameters before calling
530 * spi_add_device() on it.
532 * Caller is responsible to call spi_add_device() on the returned
533 * spi_device structure to add it to the SPI controller. If the caller
534 * needs to discard the spi_device without adding it, then it should
535 * call spi_dev_put() on it.
537 * Return: a pointer to the new device, or NULL.
539 struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
541 struct spi_device *spi;
543 if (!spi_controller_get(ctlr))
546 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
548 spi_controller_put(ctlr);
552 spi->master = spi->controller = ctlr;
553 spi->dev.parent = &ctlr->dev;
554 spi->dev.bus = &spi_bus_type;
555 spi->dev.release = spidev_release;
556 spi->cs_gpio = -ENOENT;
557 spi->mode = ctlr->buswidth_override_bits;
559 spin_lock_init(&spi->statistics.lock);
561 device_initialize(&spi->dev);
564 EXPORT_SYMBOL_GPL(spi_alloc_device);
566 static void spi_dev_set_name(struct spi_device *spi)
568 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
571 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
575 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
579 static int spi_dev_check(struct device *dev, void *data)
581 struct spi_device *spi = to_spi_device(dev);
582 struct spi_device *new_spi = data;
584 if (spi->controller == new_spi->controller &&
585 spi->chip_select == new_spi->chip_select)
590 static void spi_cleanup(struct spi_device *spi)
592 if (spi->controller->cleanup)
593 spi->controller->cleanup(spi);
596 static int __spi_add_device(struct spi_device *spi)
598 struct spi_controller *ctlr = spi->controller;
599 struct device *dev = ctlr->dev.parent;
602 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
604 dev_err(dev, "chipselect %d already in use\n",
609 /* Controller may unregister concurrently */
610 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
611 !device_is_registered(&ctlr->dev)) {
615 /* Descriptors take precedence */
617 spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
618 else if (ctlr->cs_gpios)
619 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
621 /* Drivers may modify this initial i/o setup, but will
622 * normally rely on the device being setup. Devices
623 * using SPI_CS_HIGH can't coexist well otherwise...
625 status = spi_setup(spi);
627 dev_err(dev, "can't setup %s, status %d\n",
628 dev_name(&spi->dev), status);
632 /* Device may be bound to an active driver when this returns */
633 status = device_add(&spi->dev);
635 dev_err(dev, "can't add %s, status %d\n",
636 dev_name(&spi->dev), status);
639 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
646 * spi_add_device - Add spi_device allocated with spi_alloc_device
647 * @spi: spi_device to register
649 * Companion function to spi_alloc_device. Devices allocated with
650 * spi_alloc_device can be added onto the spi bus with this function.
652 * Return: 0 on success; negative errno on failure
654 int spi_add_device(struct spi_device *spi)
656 struct spi_controller *ctlr = spi->controller;
657 struct device *dev = ctlr->dev.parent;
660 /* Chipselects are numbered 0..max; validate. */
661 if (spi->chip_select >= ctlr->num_chipselect) {
662 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
663 ctlr->num_chipselect);
667 /* Set the bus ID string */
668 spi_dev_set_name(spi);
670 /* We need to make sure there's no other device with this
671 * chipselect **BEFORE** we call setup(), else we'll trash
672 * its configuration. Lock against concurrent add() calls.
674 mutex_lock(&ctlr->add_lock);
675 status = __spi_add_device(spi);
676 mutex_unlock(&ctlr->add_lock);
679 EXPORT_SYMBOL_GPL(spi_add_device);
681 static int spi_add_device_locked(struct spi_device *spi)
683 struct spi_controller *ctlr = spi->controller;
684 struct device *dev = ctlr->dev.parent;
686 /* Chipselects are numbered 0..max; validate. */
687 if (spi->chip_select >= ctlr->num_chipselect) {
688 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
689 ctlr->num_chipselect);
693 /* Set the bus ID string */
694 spi_dev_set_name(spi);
696 WARN_ON(!mutex_is_locked(&ctlr->add_lock));
697 return __spi_add_device(spi);
701 * spi_new_device - instantiate one new SPI device
702 * @ctlr: Controller to which device is connected
703 * @chip: Describes the SPI device
706 * On typical mainboards, this is purely internal; and it's not needed
707 * after board init creates the hard-wired devices. Some development
708 * platforms may not be able to use spi_register_board_info though, and
709 * this is exported so that for example a USB or parport based adapter
710 * driver could add devices (which it would learn about out-of-band).
712 * Return: the new device, or NULL.
714 struct spi_device *spi_new_device(struct spi_controller *ctlr,
715 struct spi_board_info *chip)
717 struct spi_device *proxy;
720 /* NOTE: caller did any chip->bus_num checks necessary.
722 * Also, unless we change the return value convention to use
723 * error-or-pointer (not NULL-or-pointer), troubleshootability
724 * suggests syslogged diagnostics are best here (ugh).
727 proxy = spi_alloc_device(ctlr);
731 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
733 proxy->chip_select = chip->chip_select;
734 proxy->max_speed_hz = chip->max_speed_hz;
735 proxy->mode = chip->mode;
736 proxy->irq = chip->irq;
737 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
738 proxy->dev.platform_data = (void *) chip->platform_data;
739 proxy->controller_data = chip->controller_data;
740 proxy->controller_state = NULL;
743 status = device_add_software_node(&proxy->dev, chip->swnode);
745 dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n",
746 chip->modalias, status);
751 status = spi_add_device(proxy);
758 device_remove_software_node(&proxy->dev);
762 EXPORT_SYMBOL_GPL(spi_new_device);
765 * spi_unregister_device - unregister a single SPI device
766 * @spi: spi_device to unregister
768 * Start making the passed SPI device vanish. Normally this would be handled
769 * by spi_unregister_controller().
771 void spi_unregister_device(struct spi_device *spi)
776 if (spi->dev.of_node) {
777 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
778 of_node_put(spi->dev.of_node);
780 if (ACPI_COMPANION(&spi->dev))
781 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
782 device_remove_software_node(&spi->dev);
783 device_del(&spi->dev);
785 put_device(&spi->dev);
787 EXPORT_SYMBOL_GPL(spi_unregister_device);
789 static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
790 struct spi_board_info *bi)
792 struct spi_device *dev;
794 if (ctlr->bus_num != bi->bus_num)
797 dev = spi_new_device(ctlr, bi);
799 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
804 * spi_register_board_info - register SPI devices for a given board
805 * @info: array of chip descriptors
806 * @n: how many descriptors are provided
809 * Board-specific early init code calls this (probably during arch_initcall)
810 * with segments of the SPI device table. Any device nodes are created later,
811 * after the relevant parent SPI controller (bus_num) is defined. We keep
812 * this table of devices forever, so that reloading a controller driver will
813 * not make Linux forget about these hard-wired devices.
815 * Other code can also call this, e.g. a particular add-on board might provide
816 * SPI devices through its expansion connector, so code initializing that board
817 * would naturally declare its SPI devices.
819 * The board info passed can safely be __initdata ... but be careful of
820 * any embedded pointers (platform_data, etc), they're copied as-is.
822 * Return: zero on success, else a negative error code.
824 int spi_register_board_info(struct spi_board_info const *info, unsigned n)
826 struct boardinfo *bi;
832 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
836 for (i = 0; i < n; i++, bi++, info++) {
837 struct spi_controller *ctlr;
839 memcpy(&bi->board_info, info, sizeof(*info));
841 mutex_lock(&board_lock);
842 list_add_tail(&bi->list, &board_list);
843 list_for_each_entry(ctlr, &spi_controller_list, list)
844 spi_match_controller_to_boardinfo(ctlr,
846 mutex_unlock(&board_lock);
852 /*-------------------------------------------------------------------------*/
854 static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
856 bool activate = enable;
859 * Avoid calling into the driver (or doing delays) if the chip select
860 * isn't actually changing from the last time this was called.
862 if (!force && (spi->controller->last_cs_enable == enable) &&
863 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
866 trace_spi_set_cs(spi, activate);
868 spi->controller->last_cs_enable = enable;
869 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
871 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
872 !spi->controller->set_cs_timing) {
874 spi_delay_exec(&spi->cs_setup, NULL);
876 spi_delay_exec(&spi->cs_hold, NULL);
879 if (spi->mode & SPI_CS_HIGH)
882 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
883 if (!(spi->mode & SPI_NO_CS)) {
886 * Historically ACPI has no means of the GPIO polarity and
887 * thus the SPISerialBus() resource defines it on the per-chip
888 * basis. In order to avoid a chain of negations, the GPIO
889 * polarity is considered being Active High. Even for the cases
890 * when _DSD() is involved (in the updated versions of ACPI)
891 * the GPIO CS polarity must be defined Active High to avoid
892 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
895 if (has_acpi_companion(&spi->dev))
896 gpiod_set_value_cansleep(spi->cs_gpiod, !enable);
898 /* Polarity handled by GPIO library */
899 gpiod_set_value_cansleep(spi->cs_gpiod, activate);
902 * invert the enable line, as active low is
905 gpio_set_value_cansleep(spi->cs_gpio, !enable);
908 /* Some SPI masters need both GPIO CS & slave_select */
909 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
910 spi->controller->set_cs)
911 spi->controller->set_cs(spi, !enable);
912 } else if (spi->controller->set_cs) {
913 spi->controller->set_cs(spi, !enable);
916 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
917 !spi->controller->set_cs_timing) {
919 spi_delay_exec(&spi->cs_inactive, NULL);
923 #ifdef CONFIG_HAS_DMA
924 int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
925 struct sg_table *sgt, void *buf, size_t len,
926 enum dma_data_direction dir)
928 const bool vmalloced_buf = is_vmalloc_addr(buf);
929 unsigned int max_seg_size = dma_get_max_seg_size(dev);
930 #ifdef CONFIG_HIGHMEM
931 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
932 (unsigned long)buf < (PKMAP_BASE +
933 (LAST_PKMAP * PAGE_SIZE)));
935 const bool kmap_buf = false;
939 struct page *vm_page;
940 struct scatterlist *sg;
945 if (vmalloced_buf || kmap_buf) {
946 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
947 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
948 } else if (virt_addr_valid(buf)) {
949 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
950 sgs = DIV_ROUND_UP(len, desc_len);
955 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
960 for (i = 0; i < sgs; i++) {
962 if (vmalloced_buf || kmap_buf) {
964 * Next scatterlist entry size is the minimum between
965 * the desc_len and the remaining buffer length that
968 min = min_t(size_t, desc_len,
970 PAGE_SIZE - offset_in_page(buf)));
972 vm_page = vmalloc_to_page(buf);
974 vm_page = kmap_to_page(buf);
979 sg_set_page(sg, vm_page,
980 min, offset_in_page(buf));
982 min = min_t(size_t, len, desc_len);
984 sg_set_buf(sg, sg_buf, min);
992 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
1005 void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
1006 struct sg_table *sgt, enum dma_data_direction dir)
1008 if (sgt->orig_nents) {
1009 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
1014 static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1016 struct device *tx_dev, *rx_dev;
1017 struct spi_transfer *xfer;
1024 tx_dev = ctlr->dma_tx->device->dev;
1025 else if (ctlr->dma_map_dev)
1026 tx_dev = ctlr->dma_map_dev;
1028 tx_dev = ctlr->dev.parent;
1031 rx_dev = ctlr->dma_rx->device->dev;
1032 else if (ctlr->dma_map_dev)
1033 rx_dev = ctlr->dma_map_dev;
1035 rx_dev = ctlr->dev.parent;
1037 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1038 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1041 if (xfer->tx_buf != NULL) {
1042 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
1043 (void *)xfer->tx_buf, xfer->len,
1049 if (xfer->rx_buf != NULL) {
1050 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
1051 xfer->rx_buf, xfer->len,
1054 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
1061 ctlr->cur_msg_mapped = true;
1066 static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
1068 struct spi_transfer *xfer;
1069 struct device *tx_dev, *rx_dev;
1071 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
1075 tx_dev = ctlr->dma_tx->device->dev;
1077 tx_dev = ctlr->dev.parent;
1080 rx_dev = ctlr->dma_rx->device->dev;
1082 rx_dev = ctlr->dev.parent;
1084 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1085 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1088 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1089 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1092 ctlr->cur_msg_mapped = false;
1096 #else /* !CONFIG_HAS_DMA */
1097 static inline int __spi_map_msg(struct spi_controller *ctlr,
1098 struct spi_message *msg)
1103 static inline int __spi_unmap_msg(struct spi_controller *ctlr,
1104 struct spi_message *msg)
1108 #endif /* !CONFIG_HAS_DMA */
1110 static inline int spi_unmap_msg(struct spi_controller *ctlr,
1111 struct spi_message *msg)
1113 struct spi_transfer *xfer;
1115 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1117 * Restore the original value of tx_buf or rx_buf if they are
1120 if (xfer->tx_buf == ctlr->dummy_tx)
1121 xfer->tx_buf = NULL;
1122 if (xfer->rx_buf == ctlr->dummy_rx)
1123 xfer->rx_buf = NULL;
1126 return __spi_unmap_msg(ctlr, msg);
1129 static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1131 struct spi_transfer *xfer;
1133 unsigned int max_tx, max_rx;
1135 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1136 && !(msg->spi->mode & SPI_3WIRE)) {
1140 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1141 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1143 max_tx = max(xfer->len, max_tx);
1144 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1146 max_rx = max(xfer->len, max_rx);
1150 tmp = krealloc(ctlr->dummy_tx, max_tx,
1151 GFP_KERNEL | GFP_DMA);
1154 ctlr->dummy_tx = tmp;
1155 memset(tmp, 0, max_tx);
1159 tmp = krealloc(ctlr->dummy_rx, max_rx,
1160 GFP_KERNEL | GFP_DMA);
1163 ctlr->dummy_rx = tmp;
1166 if (max_tx || max_rx) {
1167 list_for_each_entry(xfer, &msg->transfers,
1172 xfer->tx_buf = ctlr->dummy_tx;
1174 xfer->rx_buf = ctlr->dummy_rx;
1179 return __spi_map_msg(ctlr, msg);
1182 static int spi_transfer_wait(struct spi_controller *ctlr,
1183 struct spi_message *msg,
1184 struct spi_transfer *xfer)
1186 struct spi_statistics *statm = &ctlr->statistics;
1187 struct spi_statistics *stats = &msg->spi->statistics;
1188 u32 speed_hz = xfer->speed_hz;
1189 unsigned long long ms;
1191 if (spi_controller_is_slave(ctlr)) {
1192 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1193 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1201 * For each byte we wait for 8 cycles of the SPI clock.
1202 * Since speed is defined in Hz and we want milliseconds,
1203 * use respective multiplier, but before the division,
1204 * otherwise we may get 0 for short transfers.
1206 ms = 8LL * MSEC_PER_SEC * xfer->len;
1207 do_div(ms, speed_hz);
1210 * Increase it twice and add 200 ms tolerance, use
1211 * predefined maximum in case of overflow.
1217 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1218 msecs_to_jiffies(ms));
1221 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1222 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1223 dev_err(&msg->spi->dev,
1224 "SPI transfer timed out\n");
1232 static void _spi_transfer_delay_ns(u32 ns)
1236 if (ns <= NSEC_PER_USEC) {
1239 u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC);
1244 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1248 int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1250 u32 delay = _delay->value;
1251 u32 unit = _delay->unit;
1258 case SPI_DELAY_UNIT_USECS:
1259 delay *= NSEC_PER_USEC;
1261 case SPI_DELAY_UNIT_NSECS:
1262 /* Nothing to do here */
1264 case SPI_DELAY_UNIT_SCK:
1265 /* clock cycles need to be obtained from spi_transfer */
1269 * If there is unknown effective speed, approximate it
1270 * by underestimating with half of the requested hz.
1272 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1276 /* Convert delay to nanoseconds */
1277 delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz);
1285 EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1287 int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1296 delay = spi_delay_to_ns(_delay, xfer);
1300 _spi_transfer_delay_ns(delay);
1304 EXPORT_SYMBOL_GPL(spi_delay_exec);
1306 static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1307 struct spi_transfer *xfer)
1309 u32 default_delay_ns = 10 * NSEC_PER_USEC;
1310 u32 delay = xfer->cs_change_delay.value;
1311 u32 unit = xfer->cs_change_delay.unit;
1314 /* return early on "fast" mode - for everything but USECS */
1316 if (unit == SPI_DELAY_UNIT_USECS)
1317 _spi_transfer_delay_ns(default_delay_ns);
1321 ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1323 dev_err_once(&msg->spi->dev,
1324 "Use of unsupported delay unit %i, using default of %luus\n",
1325 unit, default_delay_ns / NSEC_PER_USEC);
1326 _spi_transfer_delay_ns(default_delay_ns);
1331 * spi_transfer_one_message - Default implementation of transfer_one_message()
1333 * This is a standard implementation of transfer_one_message() for
1334 * drivers which implement a transfer_one() operation. It provides
1335 * standard handling of delays and chip select management.
1337 static int spi_transfer_one_message(struct spi_controller *ctlr,
1338 struct spi_message *msg)
1340 struct spi_transfer *xfer;
1341 bool keep_cs = false;
1343 struct spi_statistics *statm = &ctlr->statistics;
1344 struct spi_statistics *stats = &msg->spi->statistics;
1346 spi_set_cs(msg->spi, true, false);
1348 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1349 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1351 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1352 trace_spi_transfer_start(msg, xfer);
1354 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1355 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1357 if (!ctlr->ptp_sts_supported) {
1358 xfer->ptp_sts_word_pre = 0;
1359 ptp_read_system_prets(xfer->ptp_sts);
1362 if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) {
1363 reinit_completion(&ctlr->xfer_completion);
1366 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1368 if (ctlr->cur_msg_mapped &&
1369 (xfer->error & SPI_TRANS_FAIL_NO_START)) {
1370 __spi_unmap_msg(ctlr, msg);
1371 ctlr->fallback = true;
1372 xfer->error &= ~SPI_TRANS_FAIL_NO_START;
1376 SPI_STATISTICS_INCREMENT_FIELD(statm,
1378 SPI_STATISTICS_INCREMENT_FIELD(stats,
1380 dev_err(&msg->spi->dev,
1381 "SPI transfer failed: %d\n", ret);
1386 ret = spi_transfer_wait(ctlr, msg, xfer);
1392 dev_err(&msg->spi->dev,
1393 "Bufferless transfer has length %u\n",
1397 if (!ctlr->ptp_sts_supported) {
1398 ptp_read_system_postts(xfer->ptp_sts);
1399 xfer->ptp_sts_word_post = xfer->len;
1402 trace_spi_transfer_stop(msg, xfer);
1404 if (msg->status != -EINPROGRESS)
1407 spi_transfer_delay_exec(xfer);
1409 if (xfer->cs_change) {
1410 if (list_is_last(&xfer->transfer_list,
1414 spi_set_cs(msg->spi, false, false);
1415 _spi_transfer_cs_change_delay(msg, xfer);
1416 spi_set_cs(msg->spi, true, false);
1420 msg->actual_length += xfer->len;
1424 if (ret != 0 || !keep_cs)
1425 spi_set_cs(msg->spi, false, false);
1427 if (msg->status == -EINPROGRESS)
1430 if (msg->status && ctlr->handle_err)
1431 ctlr->handle_err(ctlr, msg);
1433 spi_finalize_current_message(ctlr);
1439 * spi_finalize_current_transfer - report completion of a transfer
1440 * @ctlr: the controller reporting completion
1442 * Called by SPI drivers using the core transfer_one_message()
1443 * implementation to notify it that the current interrupt driven
1444 * transfer has finished and the next one may be scheduled.
1446 void spi_finalize_current_transfer(struct spi_controller *ctlr)
1448 complete(&ctlr->xfer_completion);
1450 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1452 static void spi_idle_runtime_pm(struct spi_controller *ctlr)
1454 if (ctlr->auto_runtime_pm) {
1455 pm_runtime_mark_last_busy(ctlr->dev.parent);
1456 pm_runtime_put_autosuspend(ctlr->dev.parent);
1461 * __spi_pump_messages - function which processes spi message queue
1462 * @ctlr: controller to process queue for
1463 * @in_kthread: true if we are in the context of the message pump thread
1465 * This function checks if there is any spi message in the queue that
1466 * needs processing and if so call out to the driver to initialize hardware
1467 * and transfer each message.
1469 * Note that it is called both from the kthread itself and also from
1470 * inside spi_sync(); the queue extraction handling at the top of the
1471 * function should deal with this safely.
1473 static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1475 struct spi_transfer *xfer;
1476 struct spi_message *msg;
1477 bool was_busy = false;
1478 unsigned long flags;
1482 spin_lock_irqsave(&ctlr->queue_lock, flags);
1484 /* Make sure we are not already running a message */
1485 if (ctlr->cur_msg) {
1486 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1490 /* If another context is idling the device then defer */
1492 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1493 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1497 /* Check if the queue is idle */
1498 if (list_empty(&ctlr->queue) || !ctlr->running) {
1500 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1504 /* Defer any non-atomic teardown to the thread */
1506 if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
1507 !ctlr->unprepare_transfer_hardware) {
1508 spi_idle_runtime_pm(ctlr);
1510 trace_spi_controller_idle(ctlr);
1512 kthread_queue_work(ctlr->kworker,
1513 &ctlr->pump_messages);
1515 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1520 ctlr->idling = true;
1521 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1523 kfree(ctlr->dummy_rx);
1524 ctlr->dummy_rx = NULL;
1525 kfree(ctlr->dummy_tx);
1526 ctlr->dummy_tx = NULL;
1527 if (ctlr->unprepare_transfer_hardware &&
1528 ctlr->unprepare_transfer_hardware(ctlr))
1530 "failed to unprepare transfer hardware\n");
1531 spi_idle_runtime_pm(ctlr);
1532 trace_spi_controller_idle(ctlr);
1534 spin_lock_irqsave(&ctlr->queue_lock, flags);
1535 ctlr->idling = false;
1536 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1540 /* Extract head of queue */
1541 msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1542 ctlr->cur_msg = msg;
1544 list_del_init(&msg->queue);
1549 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1551 mutex_lock(&ctlr->io_mutex);
1553 if (!was_busy && ctlr->auto_runtime_pm) {
1554 ret = pm_runtime_get_sync(ctlr->dev.parent);
1556 pm_runtime_put_noidle(ctlr->dev.parent);
1557 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1559 mutex_unlock(&ctlr->io_mutex);
1565 trace_spi_controller_busy(ctlr);
1567 if (!was_busy && ctlr->prepare_transfer_hardware) {
1568 ret = ctlr->prepare_transfer_hardware(ctlr);
1571 "failed to prepare transfer hardware: %d\n",
1574 if (ctlr->auto_runtime_pm)
1575 pm_runtime_put(ctlr->dev.parent);
1578 spi_finalize_current_message(ctlr);
1580 mutex_unlock(&ctlr->io_mutex);
1585 trace_spi_message_start(msg);
1587 if (ctlr->prepare_message) {
1588 ret = ctlr->prepare_message(ctlr, msg);
1590 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1593 spi_finalize_current_message(ctlr);
1596 ctlr->cur_msg_prepared = true;
1599 ret = spi_map_msg(ctlr, msg);
1602 spi_finalize_current_message(ctlr);
1606 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1607 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1608 xfer->ptp_sts_word_pre = 0;
1609 ptp_read_system_prets(xfer->ptp_sts);
1613 ret = ctlr->transfer_one_message(ctlr, msg);
1616 "failed to transfer one message from queue\n");
1621 mutex_unlock(&ctlr->io_mutex);
1623 /* Prod the scheduler in case transfer_one() was busy waiting */
1629 * spi_pump_messages - kthread work function which processes spi message queue
1630 * @work: pointer to kthread work struct contained in the controller struct
1632 static void spi_pump_messages(struct kthread_work *work)
1634 struct spi_controller *ctlr =
1635 container_of(work, struct spi_controller, pump_messages);
1637 __spi_pump_messages(ctlr, true);
1641 * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
1642 * TX timestamp for the requested byte from the SPI
1643 * transfer. The frequency with which this function
1644 * must be called (once per word, once for the whole
1645 * transfer, once per batch of words etc) is arbitrary
1646 * as long as the @tx buffer offset is greater than or
1647 * equal to the requested byte at the time of the
1648 * call. The timestamp is only taken once, at the
1649 * first such call. It is assumed that the driver
1650 * advances its @tx buffer pointer monotonically.
1651 * @ctlr: Pointer to the spi_controller structure of the driver
1652 * @xfer: Pointer to the transfer being timestamped
1653 * @progress: How many words (not bytes) have been transferred so far
1654 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1655 * transfer, for less jitter in time measurement. Only compatible
1656 * with PIO drivers. If true, must follow up with
1657 * spi_take_timestamp_post or otherwise system will crash.
1658 * WARNING: for fully predictable results, the CPU frequency must
1659 * also be under control (governor).
1661 void spi_take_timestamp_pre(struct spi_controller *ctlr,
1662 struct spi_transfer *xfer,
1663 size_t progress, bool irqs_off)
1668 if (xfer->timestamped)
1671 if (progress > xfer->ptp_sts_word_pre)
1674 /* Capture the resolution of the timestamp */
1675 xfer->ptp_sts_word_pre = progress;
1678 local_irq_save(ctlr->irq_flags);
1682 ptp_read_system_prets(xfer->ptp_sts);
1684 EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
1687 * spi_take_timestamp_post - helper for drivers to collect the end of the
1688 * TX timestamp for the requested byte from the SPI
1689 * transfer. Can be called with an arbitrary
1690 * frequency: only the first call where @tx exceeds
1691 * or is equal to the requested word will be
1693 * @ctlr: Pointer to the spi_controller structure of the driver
1694 * @xfer: Pointer to the transfer being timestamped
1695 * @progress: How many words (not bytes) have been transferred so far
1696 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1698 void spi_take_timestamp_post(struct spi_controller *ctlr,
1699 struct spi_transfer *xfer,
1700 size_t progress, bool irqs_off)
1705 if (xfer->timestamped)
1708 if (progress < xfer->ptp_sts_word_post)
1711 ptp_read_system_postts(xfer->ptp_sts);
1714 local_irq_restore(ctlr->irq_flags);
1718 /* Capture the resolution of the timestamp */
1719 xfer->ptp_sts_word_post = progress;
1721 xfer->timestamped = true;
1723 EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
1726 * spi_set_thread_rt - set the controller to pump at realtime priority
1727 * @ctlr: controller to boost priority of
1729 * This can be called because the controller requested realtime priority
1730 * (by setting the ->rt value before calling spi_register_controller()) or
1731 * because a device on the bus said that its transfers needed realtime
1734 * NOTE: at the moment if any device on a bus says it needs realtime then
1735 * the thread will be at realtime priority for all transfers on that
1736 * controller. If this eventually becomes a problem we may see if we can
1737 * find a way to boost the priority only temporarily during relevant
1740 static void spi_set_thread_rt(struct spi_controller *ctlr)
1742 dev_info(&ctlr->dev,
1743 "will run message pump with realtime priority\n");
1744 sched_set_fifo(ctlr->kworker->task);
1747 static int spi_init_queue(struct spi_controller *ctlr)
1749 ctlr->running = false;
1752 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
1753 if (IS_ERR(ctlr->kworker)) {
1754 dev_err(&ctlr->dev, "failed to create message pump kworker\n");
1755 return PTR_ERR(ctlr->kworker);
1758 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1761 * Controller config will indicate if this controller should run the
1762 * message pump with high (realtime) priority to reduce the transfer
1763 * latency on the bus by minimising the delay between a transfer
1764 * request and the scheduling of the message pump thread. Without this
1765 * setting the message pump thread will remain at default priority.
1768 spi_set_thread_rt(ctlr);
1774 * spi_get_next_queued_message() - called by driver to check for queued
1776 * @ctlr: the controller to check for queued messages
1778 * If there are more messages in the queue, the next message is returned from
1781 * Return: the next message in the queue, else NULL if the queue is empty.
1783 struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1785 struct spi_message *next;
1786 unsigned long flags;
1788 /* get a pointer to the next message, if any */
1789 spin_lock_irqsave(&ctlr->queue_lock, flags);
1790 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1792 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1796 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1799 * spi_finalize_current_message() - the current message is complete
1800 * @ctlr: the controller to return the message to
1802 * Called by the driver to notify the core that the message in the front of the
1803 * queue is complete and can be removed from the queue.
1805 void spi_finalize_current_message(struct spi_controller *ctlr)
1807 struct spi_transfer *xfer;
1808 struct spi_message *mesg;
1809 unsigned long flags;
1812 spin_lock_irqsave(&ctlr->queue_lock, flags);
1813 mesg = ctlr->cur_msg;
1814 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1816 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1817 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
1818 ptp_read_system_postts(xfer->ptp_sts);
1819 xfer->ptp_sts_word_post = xfer->len;
1823 if (unlikely(ctlr->ptp_sts_supported))
1824 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
1825 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
1827 spi_unmap_msg(ctlr, mesg);
1829 /* In the prepare_messages callback the spi bus has the opportunity to
1830 * split a transfer to smaller chunks.
1831 * Release splited transfers here since spi_map_msg is done on the
1832 * splited transfers.
1834 spi_res_release(ctlr, mesg);
1836 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1837 ret = ctlr->unprepare_message(ctlr, mesg);
1839 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1844 spin_lock_irqsave(&ctlr->queue_lock, flags);
1845 ctlr->cur_msg = NULL;
1846 ctlr->cur_msg_prepared = false;
1847 ctlr->fallback = false;
1848 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1849 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1851 trace_spi_message_done(mesg);
1855 mesg->complete(mesg->context);
1857 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1859 static int spi_start_queue(struct spi_controller *ctlr)
1861 unsigned long flags;
1863 spin_lock_irqsave(&ctlr->queue_lock, flags);
1865 if (ctlr->running || ctlr->busy) {
1866 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1870 ctlr->running = true;
1871 ctlr->cur_msg = NULL;
1872 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1874 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1879 static int spi_stop_queue(struct spi_controller *ctlr)
1881 unsigned long flags;
1882 unsigned limit = 500;
1885 spin_lock_irqsave(&ctlr->queue_lock, flags);
1888 * This is a bit lame, but is optimized for the common execution path.
1889 * A wait_queue on the ctlr->busy could be used, but then the common
1890 * execution path (pump_messages) would be required to call wake_up or
1891 * friends on every SPI message. Do this instead.
1893 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1894 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1895 usleep_range(10000, 11000);
1896 spin_lock_irqsave(&ctlr->queue_lock, flags);
1899 if (!list_empty(&ctlr->queue) || ctlr->busy)
1902 ctlr->running = false;
1904 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1907 dev_warn(&ctlr->dev, "could not stop message queue\n");
1913 static int spi_destroy_queue(struct spi_controller *ctlr)
1917 ret = spi_stop_queue(ctlr);
1920 * kthread_flush_worker will block until all work is done.
1921 * If the reason that stop_queue timed out is that the work will never
1922 * finish, then it does no good to call flush/stop thread, so
1926 dev_err(&ctlr->dev, "problem destroying queue\n");
1930 kthread_destroy_worker(ctlr->kworker);
1935 static int __spi_queued_transfer(struct spi_device *spi,
1936 struct spi_message *msg,
1939 struct spi_controller *ctlr = spi->controller;
1940 unsigned long flags;
1942 spin_lock_irqsave(&ctlr->queue_lock, flags);
1944 if (!ctlr->running) {
1945 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1948 msg->actual_length = 0;
1949 msg->status = -EINPROGRESS;
1951 list_add_tail(&msg->queue, &ctlr->queue);
1952 if (!ctlr->busy && need_pump)
1953 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1955 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1960 * spi_queued_transfer - transfer function for queued transfers
1961 * @spi: spi device which is requesting transfer
1962 * @msg: spi message which is to handled is queued to driver queue
1964 * Return: zero on success, else a negative error code.
1966 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1968 return __spi_queued_transfer(spi, msg, true);
1971 static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1975 ctlr->transfer = spi_queued_transfer;
1976 if (!ctlr->transfer_one_message)
1977 ctlr->transfer_one_message = spi_transfer_one_message;
1979 /* Initialize and start queue */
1980 ret = spi_init_queue(ctlr);
1982 dev_err(&ctlr->dev, "problem initializing queue\n");
1983 goto err_init_queue;
1985 ctlr->queued = true;
1986 ret = spi_start_queue(ctlr);
1988 dev_err(&ctlr->dev, "problem starting queue\n");
1989 goto err_start_queue;
1995 spi_destroy_queue(ctlr);
2001 * spi_flush_queue - Send all pending messages in the queue from the callers'
2003 * @ctlr: controller to process queue for
2005 * This should be used when one wants to ensure all pending messages have been
2006 * sent before doing something. Is used by the spi-mem code to make sure SPI
2007 * memory operations do not preempt regular SPI transfers that have been queued
2008 * before the spi-mem operation.
2010 void spi_flush_queue(struct spi_controller *ctlr)
2012 if (ctlr->transfer == spi_queued_transfer)
2013 __spi_pump_messages(ctlr, false);
2016 /*-------------------------------------------------------------------------*/
2018 #if defined(CONFIG_OF)
2019 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
2020 struct device_node *nc)
2025 /* Mode (clock phase/polarity/etc.) */
2026 if (of_property_read_bool(nc, "spi-cpha"))
2027 spi->mode |= SPI_CPHA;
2028 if (of_property_read_bool(nc, "spi-cpol"))
2029 spi->mode |= SPI_CPOL;
2030 if (of_property_read_bool(nc, "spi-3wire"))
2031 spi->mode |= SPI_3WIRE;
2032 if (of_property_read_bool(nc, "spi-lsb-first"))
2033 spi->mode |= SPI_LSB_FIRST;
2034 if (of_property_read_bool(nc, "spi-cs-high"))
2035 spi->mode |= SPI_CS_HIGH;
2037 /* Device DUAL/QUAD mode */
2038 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
2041 spi->mode |= SPI_NO_TX;
2046 spi->mode |= SPI_TX_DUAL;
2049 spi->mode |= SPI_TX_QUAD;
2052 spi->mode |= SPI_TX_OCTAL;
2055 dev_warn(&ctlr->dev,
2056 "spi-tx-bus-width %d not supported\n",
2062 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
2065 spi->mode |= SPI_NO_RX;
2070 spi->mode |= SPI_RX_DUAL;
2073 spi->mode |= SPI_RX_QUAD;
2076 spi->mode |= SPI_RX_OCTAL;
2079 dev_warn(&ctlr->dev,
2080 "spi-rx-bus-width %d not supported\n",
2086 if (spi_controller_is_slave(ctlr)) {
2087 if (!of_node_name_eq(nc, "slave")) {
2088 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
2095 /* Device address */
2096 rc = of_property_read_u32(nc, "reg", &value);
2098 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
2102 spi->chip_select = value;
2105 if (!of_property_read_u32(nc, "spi-max-frequency", &value))
2106 spi->max_speed_hz = value;
2111 static struct spi_device *
2112 of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
2114 struct spi_device *spi;
2117 /* Alloc an spi_device */
2118 spi = spi_alloc_device(ctlr);
2120 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
2125 /* Select device driver */
2126 rc = of_modalias_node(nc, spi->modalias,
2127 sizeof(spi->modalias));
2129 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
2133 rc = of_spi_parse_dt(ctlr, spi, nc);
2137 /* Store a pointer to the node in the device structure */
2139 spi->dev.of_node = nc;
2140 spi->dev.fwnode = of_fwnode_handle(nc);
2142 /* Register the new device */
2143 rc = spi_add_device(spi);
2145 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
2146 goto err_of_node_put;
2159 * of_register_spi_devices() - Register child devices onto the SPI bus
2160 * @ctlr: Pointer to spi_controller device
2162 * Registers an spi_device for each child node of controller node which
2163 * represents a valid SPI slave.
2165 static void of_register_spi_devices(struct spi_controller *ctlr)
2167 struct spi_device *spi;
2168 struct device_node *nc;
2170 if (!ctlr->dev.of_node)
2173 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2174 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2176 spi = of_register_spi_device(ctlr, nc);
2178 dev_warn(&ctlr->dev,
2179 "Failed to create SPI device for %pOF\n", nc);
2180 of_node_clear_flag(nc, OF_POPULATED);
2185 static void of_register_spi_devices(struct spi_controller *ctlr) { }
2189 * spi_new_ancillary_device() - Register ancillary SPI device
2190 * @spi: Pointer to the main SPI device registering the ancillary device
2191 * @chip_select: Chip Select of the ancillary device
2193 * Register an ancillary SPI device; for example some chips have a chip-select
2194 * for normal device usage and another one for setup/firmware upload.
2196 * This may only be called from main SPI device's probe routine.
2198 * Return: 0 on success; negative errno on failure
2200 struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
2203 struct spi_device *ancillary;
2206 /* Alloc an spi_device */
2207 ancillary = spi_alloc_device(spi->controller);
2213 strlcpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));
2215 /* Use provided chip-select for ancillary device */
2216 ancillary->chip_select = chip_select;
2218 /* Take over SPI mode/speed from SPI main device */
2219 ancillary->max_speed_hz = spi->max_speed_hz;
2220 ancillary->mode = spi->mode;
2222 /* Register the new device */
2223 rc = spi_add_device_locked(ancillary);
2225 dev_err(&spi->dev, "failed to register ancillary device\n");
2232 spi_dev_put(ancillary);
2235 EXPORT_SYMBOL_GPL(spi_new_ancillary_device);
2238 struct acpi_spi_lookup {
2239 struct spi_controller *ctlr;
2247 static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2248 struct acpi_spi_lookup *lookup)
2250 const union acpi_object *obj;
2252 if (!x86_apple_machine)
2255 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2256 && obj->buffer.length >= 4)
2257 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2259 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2260 && obj->buffer.length == 8)
2261 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2263 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2264 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2265 lookup->mode |= SPI_LSB_FIRST;
2267 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2268 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2269 lookup->mode |= SPI_CPOL;
2271 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2272 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2273 lookup->mode |= SPI_CPHA;
2276 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2278 struct acpi_spi_lookup *lookup = data;
2279 struct spi_controller *ctlr = lookup->ctlr;
2281 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2282 struct acpi_resource_spi_serialbus *sb;
2283 acpi_handle parent_handle;
2286 sb = &ares->data.spi_serial_bus;
2287 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2289 status = acpi_get_handle(NULL,
2290 sb->resource_source.string_ptr,
2293 if (ACPI_FAILURE(status) ||
2294 ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
2298 * ACPI DeviceSelection numbering is handled by the
2299 * host controller driver in Windows and can vary
2300 * from driver to driver. In Linux we always expect
2301 * 0 .. max - 1 so we need to ask the driver to
2302 * translate between the two schemes.
2304 if (ctlr->fw_translate_cs) {
2305 int cs = ctlr->fw_translate_cs(ctlr,
2306 sb->device_selection);
2309 lookup->chip_select = cs;
2311 lookup->chip_select = sb->device_selection;
2314 lookup->max_speed_hz = sb->connection_speed;
2315 lookup->bits_per_word = sb->data_bit_length;
2317 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2318 lookup->mode |= SPI_CPHA;
2319 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2320 lookup->mode |= SPI_CPOL;
2321 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2322 lookup->mode |= SPI_CS_HIGH;
2324 } else if (lookup->irq < 0) {
2327 if (acpi_dev_resource_interrupt(ares, 0, &r))
2328 lookup->irq = r.start;
2331 /* Always tell the ACPI core to skip this resource */
2335 static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2336 struct acpi_device *adev)
2338 acpi_handle parent_handle = NULL;
2339 struct list_head resource_list;
2340 struct acpi_spi_lookup lookup = {};
2341 struct spi_device *spi;
2344 if (acpi_bus_get_status(adev) || !adev->status.present ||
2345 acpi_device_enumerated(adev))
2351 INIT_LIST_HEAD(&resource_list);
2352 ret = acpi_dev_get_resources(adev, &resource_list,
2353 acpi_spi_add_resource, &lookup);
2354 acpi_dev_free_resource_list(&resource_list);
2357 /* found SPI in _CRS but it points to another controller */
2360 if (!lookup.max_speed_hz &&
2361 ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
2362 ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {
2363 /* Apple does not use _CRS but nested devices for SPI slaves */
2364 acpi_spi_parse_apple_properties(adev, &lookup);
2367 if (!lookup.max_speed_hz)
2370 spi = spi_alloc_device(ctlr);
2372 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
2373 dev_name(&adev->dev));
2374 return AE_NO_MEMORY;
2378 ACPI_COMPANION_SET(&spi->dev, adev);
2379 spi->max_speed_hz = lookup.max_speed_hz;
2380 spi->mode |= lookup.mode;
2381 spi->irq = lookup.irq;
2382 spi->bits_per_word = lookup.bits_per_word;
2383 spi->chip_select = lookup.chip_select;
2385 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2386 sizeof(spi->modalias));
2389 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
2391 acpi_device_set_enumerated(adev);
2393 adev->power.flags.ignore_parent = true;
2394 if (spi_add_device(spi)) {
2395 adev->power.flags.ignore_parent = false;
2396 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2397 dev_name(&adev->dev));
2404 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2405 void *data, void **return_value)
2407 struct spi_controller *ctlr = data;
2408 struct acpi_device *adev;
2410 if (acpi_bus_get_device(handle, &adev))
2413 return acpi_register_spi_device(ctlr, adev);
2416 #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2418 static void acpi_register_spi_devices(struct spi_controller *ctlr)
2423 handle = ACPI_HANDLE(ctlr->dev.parent);
2427 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2428 SPI_ACPI_ENUMERATE_MAX_DEPTH,
2429 acpi_spi_add_device, NULL, ctlr, NULL);
2430 if (ACPI_FAILURE(status))
2431 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2434 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2435 #endif /* CONFIG_ACPI */
2437 static void spi_controller_release(struct device *dev)
2439 struct spi_controller *ctlr;
2441 ctlr = container_of(dev, struct spi_controller, dev);
2445 static struct class spi_master_class = {
2446 .name = "spi_master",
2447 .owner = THIS_MODULE,
2448 .dev_release = spi_controller_release,
2449 .dev_groups = spi_master_groups,
2452 #ifdef CONFIG_SPI_SLAVE
2454 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2456 * @spi: device used for the current transfer
2458 int spi_slave_abort(struct spi_device *spi)
2460 struct spi_controller *ctlr = spi->controller;
2462 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
2463 return ctlr->slave_abort(ctlr);
2467 EXPORT_SYMBOL_GPL(spi_slave_abort);
2469 static int match_true(struct device *dev, void *data)
2474 static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2477 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2479 struct device *child;
2481 child = device_find_child(&ctlr->dev, NULL, match_true);
2482 return sprintf(buf, "%s\n",
2483 child ? to_spi_device(child)->modalias : NULL);
2486 static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
2487 const char *buf, size_t count)
2489 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2491 struct spi_device *spi;
2492 struct device *child;
2496 rc = sscanf(buf, "%31s", name);
2497 if (rc != 1 || !name[0])
2500 child = device_find_child(&ctlr->dev, NULL, match_true);
2502 /* Remove registered slave */
2503 device_unregister(child);
2507 if (strcmp(name, "(null)")) {
2508 /* Register new slave */
2509 spi = spi_alloc_device(ctlr);
2513 strlcpy(spi->modalias, name, sizeof(spi->modalias));
2515 rc = spi_add_device(spi);
2525 static DEVICE_ATTR_RW(slave);
2527 static struct attribute *spi_slave_attrs[] = {
2528 &dev_attr_slave.attr,
2532 static const struct attribute_group spi_slave_group = {
2533 .attrs = spi_slave_attrs,
2536 static const struct attribute_group *spi_slave_groups[] = {
2537 &spi_controller_statistics_group,
2542 static struct class spi_slave_class = {
2543 .name = "spi_slave",
2544 .owner = THIS_MODULE,
2545 .dev_release = spi_controller_release,
2546 .dev_groups = spi_slave_groups,
2549 extern struct class spi_slave_class; /* dummy */
2553 * __spi_alloc_controller - allocate an SPI master or slave controller
2554 * @dev: the controller, possibly using the platform_bus
2555 * @size: how much zeroed driver-private data to allocate; the pointer to this
2556 * memory is in the driver_data field of the returned device, accessible
2557 * with spi_controller_get_devdata(); the memory is cacheline aligned;
2558 * drivers granting DMA access to portions of their private data need to
2559 * round up @size using ALIGN(size, dma_get_cache_alignment()).
2560 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2561 * slave (true) controller
2562 * Context: can sleep
2564 * This call is used only by SPI controller drivers, which are the
2565 * only ones directly touching chip registers. It's how they allocate
2566 * an spi_controller structure, prior to calling spi_register_controller().
2568 * This must be called from context that can sleep.
2570 * The caller is responsible for assigning the bus number and initializing the
2571 * controller's methods before calling spi_register_controller(); and (after
2572 * errors adding the device) calling spi_controller_put() to prevent a memory
2575 * Return: the SPI controller structure on success, else NULL.
2577 struct spi_controller *__spi_alloc_controller(struct device *dev,
2578 unsigned int size, bool slave)
2580 struct spi_controller *ctlr;
2581 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
2586 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
2590 device_initialize(&ctlr->dev);
2591 INIT_LIST_HEAD(&ctlr->queue);
2592 spin_lock_init(&ctlr->queue_lock);
2593 spin_lock_init(&ctlr->bus_lock_spinlock);
2594 mutex_init(&ctlr->bus_lock_mutex);
2595 mutex_init(&ctlr->io_mutex);
2596 mutex_init(&ctlr->add_lock);
2598 ctlr->num_chipselect = 1;
2599 ctlr->slave = slave;
2600 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2601 ctlr->dev.class = &spi_slave_class;
2603 ctlr->dev.class = &spi_master_class;
2604 ctlr->dev.parent = dev;
2605 pm_suspend_ignore_children(&ctlr->dev, true);
2606 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
2610 EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2612 static void devm_spi_release_controller(struct device *dev, void *ctlr)
2614 spi_controller_put(*(struct spi_controller **)ctlr);
2618 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
2619 * @dev: physical device of SPI controller
2620 * @size: how much zeroed driver-private data to allocate
2621 * @slave: whether to allocate an SPI master (false) or SPI slave (true)
2622 * Context: can sleep
2624 * Allocate an SPI controller and automatically release a reference on it
2625 * when @dev is unbound from its driver. Drivers are thus relieved from
2626 * having to call spi_controller_put().
2628 * The arguments to this function are identical to __spi_alloc_controller().
2630 * Return: the SPI controller structure on success, else NULL.
2632 struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
2636 struct spi_controller **ptr, *ctlr;
2638 ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),
2643 ctlr = __spi_alloc_controller(dev, size, slave);
2645 ctlr->devm_allocated = true;
2647 devres_add(dev, ptr);
2654 EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);
2657 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2660 struct device_node *np = ctlr->dev.of_node;
2665 nb = of_gpio_named_count(np, "cs-gpios");
2666 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2668 /* Return error only for an incorrectly formed cs-gpios property */
2669 if (nb == 0 || nb == -ENOENT)
2674 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2676 ctlr->cs_gpios = cs;
2678 if (!ctlr->cs_gpios)
2681 for (i = 0; i < ctlr->num_chipselect; i++)
2684 for (i = 0; i < nb; i++)
2685 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2690 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2697 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2698 * @ctlr: The SPI master to grab GPIO descriptors for
2700 static int spi_get_gpio_descs(struct spi_controller *ctlr)
2703 struct gpio_desc **cs;
2704 struct device *dev = &ctlr->dev;
2705 unsigned long native_cs_mask = 0;
2706 unsigned int num_cs_gpios = 0;
2708 nb = gpiod_count(dev, "cs");
2710 /* No GPIOs at all is fine, else return the error */
2716 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2718 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
2722 ctlr->cs_gpiods = cs;
2724 for (i = 0; i < nb; i++) {
2726 * Most chipselects are active low, the inverted
2727 * semantics are handled by special quirks in gpiolib,
2728 * so initializing them GPIOD_OUT_LOW here means
2729 * "unasserted", in most cases this will drive the physical
2732 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
2735 return PTR_ERR(cs[i]);
2739 * If we find a CS GPIO, name it after the device and
2744 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
2748 gpiod_set_consumer_name(cs[i], gpioname);
2753 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
2754 dev_err(dev, "Invalid native chip select %d\n", i);
2757 native_cs_mask |= BIT(i);
2760 ctlr->unused_native_cs = ffs(~native_cs_mask) - 1;
2762 if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios &&
2763 ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {
2764 dev_err(dev, "No unused native chip select available\n");
2771 static int spi_controller_check_ops(struct spi_controller *ctlr)
2774 * The controller may implement only the high-level SPI-memory like
2775 * operations if it does not support regular SPI transfers, and this is
2777 * If ->mem_ops is NULL, we request that at least one of the
2778 * ->transfer_xxx() method be implemented.
2780 if (ctlr->mem_ops) {
2781 if (!ctlr->mem_ops->exec_op)
2783 } else if (!ctlr->transfer && !ctlr->transfer_one &&
2784 !ctlr->transfer_one_message) {
2792 * spi_register_controller - register SPI master or slave controller
2793 * @ctlr: initialized master, originally from spi_alloc_master() or
2795 * Context: can sleep
2797 * SPI controllers connect to their drivers using some non-SPI bus,
2798 * such as the platform bus. The final stage of probe() in that code
2799 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2801 * SPI controllers use board specific (often SOC specific) bus numbers,
2802 * and board-specific addressing for SPI devices combines those numbers
2803 * with chip select numbers. Since SPI does not directly support dynamic
2804 * device identification, boards need configuration tables telling which
2805 * chip is at which address.
2807 * This must be called from context that can sleep. It returns zero on
2808 * success, else a negative error code (dropping the controller's refcount).
2809 * After a successful return, the caller is responsible for calling
2810 * spi_unregister_controller().
2812 * Return: zero on success, else a negative error code.
2814 int spi_register_controller(struct spi_controller *ctlr)
2816 struct device *dev = ctlr->dev.parent;
2817 struct boardinfo *bi;
2819 int id, first_dynamic;
2825 * Make sure all necessary hooks are implemented before registering
2826 * the SPI controller.
2828 status = spi_controller_check_ops(ctlr);
2832 if (ctlr->bus_num >= 0) {
2833 /* devices with a fixed bus num must check-in with the num */
2834 mutex_lock(&board_lock);
2835 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2836 ctlr->bus_num + 1, GFP_KERNEL);
2837 mutex_unlock(&board_lock);
2838 if (WARN(id < 0, "couldn't get idr"))
2839 return id == -ENOSPC ? -EBUSY : id;
2841 } else if (ctlr->dev.of_node) {
2842 /* allocate dynamic bus number using Linux idr */
2843 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2846 mutex_lock(&board_lock);
2847 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2848 ctlr->bus_num + 1, GFP_KERNEL);
2849 mutex_unlock(&board_lock);
2850 if (WARN(id < 0, "couldn't get idr"))
2851 return id == -ENOSPC ? -EBUSY : id;
2854 if (ctlr->bus_num < 0) {
2855 first_dynamic = of_alias_get_highest_id("spi");
2856 if (first_dynamic < 0)
2861 mutex_lock(&board_lock);
2862 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2864 mutex_unlock(&board_lock);
2865 if (WARN(id < 0, "couldn't get idr"))
2869 ctlr->bus_lock_flag = 0;
2870 init_completion(&ctlr->xfer_completion);
2871 if (!ctlr->max_dma_len)
2872 ctlr->max_dma_len = INT_MAX;
2874 /* register the device, then userspace will see it.
2875 * registration fails if the bus ID is in use.
2877 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2879 if (!spi_controller_is_slave(ctlr)) {
2880 if (ctlr->use_gpio_descriptors) {
2881 status = spi_get_gpio_descs(ctlr);
2885 * A controller using GPIO descriptors always
2886 * supports SPI_CS_HIGH if need be.
2888 ctlr->mode_bits |= SPI_CS_HIGH;
2890 /* Legacy code path for GPIOs from DT */
2891 status = of_spi_get_gpio_numbers(ctlr);
2898 * Even if it's just one always-selected device, there must
2899 * be at least one chipselect.
2901 if (!ctlr->num_chipselect) {
2906 status = device_add(&ctlr->dev);
2909 dev_dbg(dev, "registered %s %s\n",
2910 spi_controller_is_slave(ctlr) ? "slave" : "master",
2911 dev_name(&ctlr->dev));
2914 * If we're using a queued driver, start the queue. Note that we don't
2915 * need the queueing logic if the driver is only supporting high-level
2916 * memory operations.
2918 if (ctlr->transfer) {
2919 dev_info(dev, "controller is unqueued, this is deprecated\n");
2920 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2921 status = spi_controller_initialize_queue(ctlr);
2923 device_del(&ctlr->dev);
2927 /* add statistics */
2928 spin_lock_init(&ctlr->statistics.lock);
2930 mutex_lock(&board_lock);
2931 list_add_tail(&ctlr->list, &spi_controller_list);
2932 list_for_each_entry(bi, &board_list, list)
2933 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2934 mutex_unlock(&board_lock);
2936 /* Register devices from the device tree and ACPI */
2937 of_register_spi_devices(ctlr);
2938 acpi_register_spi_devices(ctlr);
2942 mutex_lock(&board_lock);
2943 idr_remove(&spi_master_idr, ctlr->bus_num);
2944 mutex_unlock(&board_lock);
2947 EXPORT_SYMBOL_GPL(spi_register_controller);
2949 static void devm_spi_unregister(void *ctlr)
2951 spi_unregister_controller(ctlr);
2955 * devm_spi_register_controller - register managed SPI master or slave
2957 * @dev: device managing SPI controller
2958 * @ctlr: initialized controller, originally from spi_alloc_master() or
2960 * Context: can sleep
2962 * Register a SPI device as with spi_register_controller() which will
2963 * automatically be unregistered and freed.
2965 * Return: zero on success, else a negative error code.
2967 int devm_spi_register_controller(struct device *dev,
2968 struct spi_controller *ctlr)
2972 ret = spi_register_controller(ctlr);
2976 return devm_add_action_or_reset(dev, devm_spi_unregister, ctlr);
2978 EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2980 static int __unregister(struct device *dev, void *null)
2982 spi_unregister_device(to_spi_device(dev));
2987 * spi_unregister_controller - unregister SPI master or slave controller
2988 * @ctlr: the controller being unregistered
2989 * Context: can sleep
2991 * This call is used only by SPI controller drivers, which are the
2992 * only ones directly touching chip registers.
2994 * This must be called from context that can sleep.
2996 * Note that this function also drops a reference to the controller.
2998 void spi_unregister_controller(struct spi_controller *ctlr)
3000 struct spi_controller *found;
3001 int id = ctlr->bus_num;
3003 /* Prevent addition of new devices, unregister existing ones */
3004 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
3005 mutex_lock(&ctlr->add_lock);
3007 device_for_each_child(&ctlr->dev, NULL, __unregister);
3009 /* First make sure that this controller was ever added */
3010 mutex_lock(&board_lock);
3011 found = idr_find(&spi_master_idr, id);
3012 mutex_unlock(&board_lock);
3014 if (spi_destroy_queue(ctlr))
3015 dev_err(&ctlr->dev, "queue remove failed\n");
3017 mutex_lock(&board_lock);
3018 list_del(&ctlr->list);
3019 mutex_unlock(&board_lock);
3021 device_del(&ctlr->dev);
3024 mutex_lock(&board_lock);
3026 idr_remove(&spi_master_idr, id);
3027 mutex_unlock(&board_lock);
3029 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
3030 mutex_unlock(&ctlr->add_lock);
3032 /* Release the last reference on the controller if its driver
3033 * has not yet been converted to devm_spi_alloc_master/slave().
3035 if (!ctlr->devm_allocated)
3036 put_device(&ctlr->dev);
3038 EXPORT_SYMBOL_GPL(spi_unregister_controller);
3040 int spi_controller_suspend(struct spi_controller *ctlr)
3044 /* Basically no-ops for non-queued controllers */
3048 ret = spi_stop_queue(ctlr);
3050 dev_err(&ctlr->dev, "queue stop failed\n");
3054 EXPORT_SYMBOL_GPL(spi_controller_suspend);
3056 int spi_controller_resume(struct spi_controller *ctlr)
3063 ret = spi_start_queue(ctlr);
3065 dev_err(&ctlr->dev, "queue restart failed\n");
3069 EXPORT_SYMBOL_GPL(spi_controller_resume);
3071 static int __spi_controller_match(struct device *dev, const void *data)
3073 struct spi_controller *ctlr;
3074 const u16 *bus_num = data;
3076 ctlr = container_of(dev, struct spi_controller, dev);
3077 return ctlr->bus_num == *bus_num;
3081 * spi_busnum_to_master - look up master associated with bus_num
3082 * @bus_num: the master's bus number
3083 * Context: can sleep
3085 * This call may be used with devices that are registered after
3086 * arch init time. It returns a refcounted pointer to the relevant
3087 * spi_controller (which the caller must release), or NULL if there is
3088 * no such master registered.
3090 * Return: the SPI master structure on success, else NULL.
3092 struct spi_controller *spi_busnum_to_master(u16 bus_num)
3095 struct spi_controller *ctlr = NULL;
3097 dev = class_find_device(&spi_master_class, NULL, &bus_num,
3098 __spi_controller_match);
3100 ctlr = container_of(dev, struct spi_controller, dev);
3101 /* reference got in class_find_device */
3104 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
3106 /*-------------------------------------------------------------------------*/
3108 /* Core methods for SPI resource management */
3111 * spi_res_alloc - allocate a spi resource that is life-cycle managed
3112 * during the processing of a spi_message while using
3114 * @spi: the spi device for which we allocate memory
3115 * @release: the release code to execute for this resource
3116 * @size: size to alloc and return
3117 * @gfp: GFP allocation flags
3119 * Return: the pointer to the allocated data
3121 * This may get enhanced in the future to allocate from a memory pool
3122 * of the @spi_device or @spi_controller to avoid repeated allocations.
3124 void *spi_res_alloc(struct spi_device *spi,
3125 spi_res_release_t release,
3126 size_t size, gfp_t gfp)
3128 struct spi_res *sres;
3130 sres = kzalloc(sizeof(*sres) + size, gfp);
3134 INIT_LIST_HEAD(&sres->entry);
3135 sres->release = release;
3139 EXPORT_SYMBOL_GPL(spi_res_alloc);
3142 * spi_res_free - free an spi resource
3143 * @res: pointer to the custom data of a resource
3146 void spi_res_free(void *res)
3148 struct spi_res *sres = container_of(res, struct spi_res, data);
3153 WARN_ON(!list_empty(&sres->entry));
3156 EXPORT_SYMBOL_GPL(spi_res_free);
3159 * spi_res_add - add a spi_res to the spi_message
3160 * @message: the spi message
3161 * @res: the spi_resource
3163 void spi_res_add(struct spi_message *message, void *res)
3165 struct spi_res *sres = container_of(res, struct spi_res, data);
3167 WARN_ON(!list_empty(&sres->entry));
3168 list_add_tail(&sres->entry, &message->resources);
3170 EXPORT_SYMBOL_GPL(spi_res_add);
3173 * spi_res_release - release all spi resources for this message
3174 * @ctlr: the @spi_controller
3175 * @message: the @spi_message
3177 void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
3179 struct spi_res *res, *tmp;
3181 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
3183 res->release(ctlr, message, res->data);
3185 list_del(&res->entry);
3190 EXPORT_SYMBOL_GPL(spi_res_release);
3192 /*-------------------------------------------------------------------------*/
3194 /* Core methods for spi_message alterations */
3196 static void __spi_replace_transfers_release(struct spi_controller *ctlr,
3197 struct spi_message *msg,
3200 struct spi_replaced_transfers *rxfer = res;
3203 /* call extra callback if requested */
3205 rxfer->release(ctlr, msg, res);
3207 /* insert replaced transfers back into the message */
3208 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
3210 /* remove the formerly inserted entries */
3211 for (i = 0; i < rxfer->inserted; i++)
3212 list_del(&rxfer->inserted_transfers[i].transfer_list);
3216 * spi_replace_transfers - replace transfers with several transfers
3217 * and register change with spi_message.resources
3218 * @msg: the spi_message we work upon
3219 * @xfer_first: the first spi_transfer we want to replace
3220 * @remove: number of transfers to remove
3221 * @insert: the number of transfers we want to insert instead
3222 * @release: extra release code necessary in some circumstances
3223 * @extradatasize: extra data to allocate (with alignment guarantees
3224 * of struct @spi_transfer)
3227 * Returns: pointer to @spi_replaced_transfers,
3228 * PTR_ERR(...) in case of errors.
3230 struct spi_replaced_transfers *spi_replace_transfers(
3231 struct spi_message *msg,
3232 struct spi_transfer *xfer_first,
3235 spi_replaced_release_t release,
3236 size_t extradatasize,
3239 struct spi_replaced_transfers *rxfer;
3240 struct spi_transfer *xfer;
3243 /* allocate the structure using spi_res */
3244 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
3245 struct_size(rxfer, inserted_transfers, insert)
3249 return ERR_PTR(-ENOMEM);
3251 /* the release code to invoke before running the generic release */
3252 rxfer->release = release;
3254 /* assign extradata */
3257 &rxfer->inserted_transfers[insert];
3259 /* init the replaced_transfers list */
3260 INIT_LIST_HEAD(&rxfer->replaced_transfers);
3262 /* assign the list_entry after which we should reinsert
3263 * the @replaced_transfers - it may be spi_message.messages!
3265 rxfer->replaced_after = xfer_first->transfer_list.prev;
3267 /* remove the requested number of transfers */
3268 for (i = 0; i < remove; i++) {
3269 /* if the entry after replaced_after it is msg->transfers
3270 * then we have been requested to remove more transfers
3271 * than are in the list
3273 if (rxfer->replaced_after->next == &msg->transfers) {
3274 dev_err(&msg->spi->dev,
3275 "requested to remove more spi_transfers than are available\n");
3276 /* insert replaced transfers back into the message */
3277 list_splice(&rxfer->replaced_transfers,
3278 rxfer->replaced_after);
3280 /* free the spi_replace_transfer structure */
3281 spi_res_free(rxfer);
3283 /* and return with an error */
3284 return ERR_PTR(-EINVAL);
3287 /* remove the entry after replaced_after from list of
3288 * transfers and add it to list of replaced_transfers
3290 list_move_tail(rxfer->replaced_after->next,
3291 &rxfer->replaced_transfers);
3294 /* create copy of the given xfer with identical settings
3295 * based on the first transfer to get removed
3297 for (i = 0; i < insert; i++) {
3298 /* we need to run in reverse order */
3299 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3301 /* copy all spi_transfer data */
3302 memcpy(xfer, xfer_first, sizeof(*xfer));
3305 list_add(&xfer->transfer_list, rxfer->replaced_after);
3307 /* clear cs_change and delay for all but the last */
3309 xfer->cs_change = false;
3310 xfer->delay.value = 0;
3314 /* set up inserted */
3315 rxfer->inserted = insert;
3317 /* and register it with spi_res/spi_message */
3318 spi_res_add(msg, rxfer);
3322 EXPORT_SYMBOL_GPL(spi_replace_transfers);
3324 static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3325 struct spi_message *msg,
3326 struct spi_transfer **xferp,
3330 struct spi_transfer *xfer = *xferp, *xfers;
3331 struct spi_replaced_transfers *srt;
3335 /* calculate how many we have to replace */
3336 count = DIV_ROUND_UP(xfer->len, maxsize);
3338 /* create replacement */
3339 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
3341 return PTR_ERR(srt);
3342 xfers = srt->inserted_transfers;
3344 /* now handle each of those newly inserted spi_transfers
3345 * note that the replacements spi_transfers all are preset
3346 * to the same values as *xferp, so tx_buf, rx_buf and len
3347 * are all identical (as well as most others)
3348 * so we just have to fix up len and the pointers.
3350 * this also includes support for the depreciated
3351 * spi_message.is_dma_mapped interface
3354 /* the first transfer just needs the length modified, so we
3355 * run it outside the loop
3357 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3359 /* all the others need rx_buf/tx_buf also set */
3360 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3361 /* update rx_buf, tx_buf and dma */
3362 if (xfers[i].rx_buf)
3363 xfers[i].rx_buf += offset;
3364 if (xfers[i].rx_dma)
3365 xfers[i].rx_dma += offset;
3366 if (xfers[i].tx_buf)
3367 xfers[i].tx_buf += offset;
3368 if (xfers[i].tx_dma)
3369 xfers[i].tx_dma += offset;
3372 xfers[i].len = min(maxsize, xfers[i].len - offset);
3375 /* we set up xferp to the last entry we have inserted,
3376 * so that we skip those already split transfers
3378 *xferp = &xfers[count - 1];
3380 /* increment statistics counters */
3381 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3382 transfers_split_maxsize);
3383 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
3384 transfers_split_maxsize);
3390 * spi_split_transfers_maxsize - split spi transfers into multiple transfers
3391 * when an individual transfer exceeds a
3393 * @ctlr: the @spi_controller for this transfer
3394 * @msg: the @spi_message to transform
3395 * @maxsize: the maximum when to apply this
3396 * @gfp: GFP allocation flags
3398 * Return: status of transformation
3400 int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3401 struct spi_message *msg,
3405 struct spi_transfer *xfer;
3408 /* iterate over the transfer_list,
3409 * but note that xfer is advanced to the last transfer inserted
3410 * to avoid checking sizes again unnecessarily (also xfer does
3411 * potentiall belong to a different list by the time the
3412 * replacement has happened
3414 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3415 if (xfer->len > maxsize) {
3416 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3425 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3427 /*-------------------------------------------------------------------------*/
3429 /* Core methods for SPI controller protocol drivers. Some of the
3430 * other core methods are currently defined as inline functions.
3433 static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3436 if (ctlr->bits_per_word_mask) {
3437 /* Only 32 bits fit in the mask */
3438 if (bits_per_word > 32)
3440 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3448 * spi_setup - setup SPI mode and clock rate
3449 * @spi: the device whose settings are being modified
3450 * Context: can sleep, and no requests are queued to the device
3452 * SPI protocol drivers may need to update the transfer mode if the
3453 * device doesn't work with its default. They may likewise need
3454 * to update clock rates or word sizes from initial values. This function
3455 * changes those settings, and must be called from a context that can sleep.
3456 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3457 * effect the next time the device is selected and data is transferred to
3458 * or from it. When this function returns, the spi device is deselected.
3460 * Note that this call will fail if the protocol driver specifies an option
3461 * that the underlying controller or its driver does not support. For
3462 * example, not all hardware supports wire transfers using nine bit words,
3463 * LSB-first wire encoding, or active-high chipselects.
3465 * Return: zero on success, else a negative error code.
3467 int spi_setup(struct spi_device *spi)
3469 unsigned bad_bits, ugly_bits;
3473 * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
3474 * are set at the same time
3476 if ((hweight_long(spi->mode &
3477 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
3478 (hweight_long(spi->mode &
3479 (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
3481 "setup: can not select any two of dual, quad and no-rx/tx at the same time\n");
3484 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
3486 if ((spi->mode & SPI_3WIRE) && (spi->mode &
3487 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3488 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3490 /* help drivers fail *cleanly* when they need options
3491 * that aren't supported with their current controller
3492 * SPI_CS_WORD has a fallback software implementation,
3493 * so it is ignored here.
3495 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
3496 SPI_NO_TX | SPI_NO_RX);
3497 /* nothing prevents from working with active-high CS in case if it
3498 * is driven by GPIO.
3500 if (gpio_is_valid(spi->cs_gpio))
3501 bad_bits &= ~SPI_CS_HIGH;
3502 ugly_bits = bad_bits &
3503 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3504 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3507 "setup: ignoring unsupported mode bits %x\n",
3509 spi->mode &= ~ugly_bits;
3510 bad_bits &= ~ugly_bits;
3513 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3518 if (!spi->bits_per_word)
3519 spi->bits_per_word = 8;
3521 status = __spi_validate_bits_per_word(spi->controller,
3522 spi->bits_per_word);
3526 if (spi->controller->max_speed_hz &&
3527 (!spi->max_speed_hz ||
3528 spi->max_speed_hz > spi->controller->max_speed_hz))
3529 spi->max_speed_hz = spi->controller->max_speed_hz;
3531 mutex_lock(&spi->controller->io_mutex);
3533 if (spi->controller->setup) {
3534 status = spi->controller->setup(spi);
3536 mutex_unlock(&spi->controller->io_mutex);
3537 dev_err(&spi->controller->dev, "Failed to setup device: %d\n",
3543 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
3544 status = pm_runtime_get_sync(spi->controller->dev.parent);
3546 mutex_unlock(&spi->controller->io_mutex);
3547 pm_runtime_put_noidle(spi->controller->dev.parent);
3548 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3554 * We do not want to return positive value from pm_runtime_get,
3555 * there are many instances of devices calling spi_setup() and
3556 * checking for a non-zero return value instead of a negative
3561 spi_set_cs(spi, false, true);
3562 pm_runtime_mark_last_busy(spi->controller->dev.parent);
3563 pm_runtime_put_autosuspend(spi->controller->dev.parent);
3565 spi_set_cs(spi, false, true);
3568 mutex_unlock(&spi->controller->io_mutex);
3570 if (spi->rt && !spi->controller->rt) {
3571 spi->controller->rt = true;
3572 spi_set_thread_rt(spi->controller);
3575 trace_spi_setup(spi, status);
3577 dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3578 spi->mode & SPI_MODE_X_MASK,
3579 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
3580 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
3581 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
3582 (spi->mode & SPI_LOOP) ? "loopback, " : "",
3583 spi->bits_per_word, spi->max_speed_hz,
3588 EXPORT_SYMBOL_GPL(spi_setup);
3590 static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
3591 struct spi_device *spi)
3595 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
3599 delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
3603 if (delay1 < delay2)
3604 memcpy(&xfer->word_delay, &spi->word_delay,
3605 sizeof(xfer->word_delay));
3610 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
3612 struct spi_controller *ctlr = spi->controller;
3613 struct spi_transfer *xfer;
3616 if (list_empty(&message->transfers))
3619 /* If an SPI controller does not support toggling the CS line on each
3620 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3621 * for the CS line, we can emulate the CS-per-word hardware function by
3622 * splitting transfers into one-word transfers and ensuring that
3623 * cs_change is set for each transfer.
3625 if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
3627 gpio_is_valid(spi->cs_gpio))) {
3631 maxsize = (spi->bits_per_word + 7) / 8;
3633 /* spi_split_transfers_maxsize() requires message->spi */
3636 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
3641 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3642 /* don't change cs_change on the last entry in the list */
3643 if (list_is_last(&xfer->transfer_list, &message->transfers))
3645 xfer->cs_change = 1;
3649 /* Half-duplex links include original MicroWire, and ones with
3650 * only one data pin like SPI_3WIRE (switches direction) or where
3651 * either MOSI or MISO is missing. They can also be caused by
3652 * software limitations.
3654 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
3655 (spi->mode & SPI_3WIRE)) {
3656 unsigned flags = ctlr->flags;
3658 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3659 if (xfer->rx_buf && xfer->tx_buf)
3661 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
3663 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
3669 * Set transfer bits_per_word and max speed as spi device default if
3670 * it is not set for this transfer.
3671 * Set transfer tx_nbits and rx_nbits as single transfer default
3672 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3673 * Ensure transfer word_delay is at least as long as that required by
3676 message->frame_length = 0;
3677 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3678 xfer->effective_speed_hz = 0;
3679 message->frame_length += xfer->len;
3680 if (!xfer->bits_per_word)
3681 xfer->bits_per_word = spi->bits_per_word;
3683 if (!xfer->speed_hz)
3684 xfer->speed_hz = spi->max_speed_hz;
3686 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
3687 xfer->speed_hz = ctlr->max_speed_hz;
3689 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
3693 * SPI transfer length should be multiple of SPI word size
3694 * where SPI word size should be power-of-two multiple
3696 if (xfer->bits_per_word <= 8)
3698 else if (xfer->bits_per_word <= 16)
3703 /* No partial transfers accepted */
3704 if (xfer->len % w_size)
3707 if (xfer->speed_hz && ctlr->min_speed_hz &&
3708 xfer->speed_hz < ctlr->min_speed_hz)
3711 if (xfer->tx_buf && !xfer->tx_nbits)
3712 xfer->tx_nbits = SPI_NBITS_SINGLE;
3713 if (xfer->rx_buf && !xfer->rx_nbits)
3714 xfer->rx_nbits = SPI_NBITS_SINGLE;
3715 /* check transfer tx/rx_nbits:
3716 * 1. check the value matches one of single, dual and quad
3717 * 2. check tx/rx_nbits match the mode in spi_device
3720 if (spi->mode & SPI_NO_TX)
3722 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3723 xfer->tx_nbits != SPI_NBITS_DUAL &&
3724 xfer->tx_nbits != SPI_NBITS_QUAD)
3726 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3727 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3729 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3730 !(spi->mode & SPI_TX_QUAD))
3733 /* check transfer rx_nbits */
3735 if (spi->mode & SPI_NO_RX)
3737 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3738 xfer->rx_nbits != SPI_NBITS_DUAL &&
3739 xfer->rx_nbits != SPI_NBITS_QUAD)
3741 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3742 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3744 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3745 !(spi->mode & SPI_RX_QUAD))
3749 if (_spi_xfer_word_delay_update(xfer, spi))
3753 message->status = -EINPROGRESS;
3758 static int __spi_async(struct spi_device *spi, struct spi_message *message)
3760 struct spi_controller *ctlr = spi->controller;
3761 struct spi_transfer *xfer;
3764 * Some controllers do not support doing regular SPI transfers. Return
3765 * ENOTSUPP when this is the case.
3767 if (!ctlr->transfer)
3772 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
3773 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3775 trace_spi_message_submit(message);
3777 if (!ctlr->ptp_sts_supported) {
3778 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3779 xfer->ptp_sts_word_pre = 0;
3780 ptp_read_system_prets(xfer->ptp_sts);
3784 return ctlr->transfer(spi, message);
3788 * spi_async - asynchronous SPI transfer
3789 * @spi: device with which data will be exchanged
3790 * @message: describes the data transfers, including completion callback
3791 * Context: any (irqs may be blocked, etc)
3793 * This call may be used in_irq and other contexts which can't sleep,
3794 * as well as from task contexts which can sleep.
3796 * The completion callback is invoked in a context which can't sleep.
3797 * Before that invocation, the value of message->status is undefined.
3798 * When the callback is issued, message->status holds either zero (to
3799 * indicate complete success) or a negative error code. After that
3800 * callback returns, the driver which issued the transfer request may
3801 * deallocate the associated memory; it's no longer in use by any SPI
3802 * core or controller driver code.
3804 * Note that although all messages to a spi_device are handled in
3805 * FIFO order, messages may go to different devices in other orders.
3806 * Some device might be higher priority, or have various "hard" access
3807 * time requirements, for example.
3809 * On detection of any fault during the transfer, processing of
3810 * the entire message is aborted, and the device is deselected.
3811 * Until returning from the associated message completion callback,
3812 * no other spi_message queued to that device will be processed.
3813 * (This rule applies equally to all the synchronous transfer calls,
3814 * which are wrappers around this core asynchronous primitive.)
3816 * Return: zero on success, else a negative error code.
3818 int spi_async(struct spi_device *spi, struct spi_message *message)
3820 struct spi_controller *ctlr = spi->controller;
3822 unsigned long flags;
3824 ret = __spi_validate(spi, message);
3828 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3830 if (ctlr->bus_lock_flag)
3833 ret = __spi_async(spi, message);
3835 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3839 EXPORT_SYMBOL_GPL(spi_async);
3842 * spi_async_locked - version of spi_async with exclusive bus usage
3843 * @spi: device with which data will be exchanged
3844 * @message: describes the data transfers, including completion callback
3845 * Context: any (irqs may be blocked, etc)
3847 * This call may be used in_irq and other contexts which can't sleep,
3848 * as well as from task contexts which can sleep.
3850 * The completion callback is invoked in a context which can't sleep.
3851 * Before that invocation, the value of message->status is undefined.
3852 * When the callback is issued, message->status holds either zero (to
3853 * indicate complete success) or a negative error code. After that
3854 * callback returns, the driver which issued the transfer request may
3855 * deallocate the associated memory; it's no longer in use by any SPI
3856 * core or controller driver code.
3858 * Note that although all messages to a spi_device are handled in
3859 * FIFO order, messages may go to different devices in other orders.
3860 * Some device might be higher priority, or have various "hard" access
3861 * time requirements, for example.
3863 * On detection of any fault during the transfer, processing of
3864 * the entire message is aborted, and the device is deselected.
3865 * Until returning from the associated message completion callback,
3866 * no other spi_message queued to that device will be processed.
3867 * (This rule applies equally to all the synchronous transfer calls,
3868 * which are wrappers around this core asynchronous primitive.)
3870 * Return: zero on success, else a negative error code.
3872 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3874 struct spi_controller *ctlr = spi->controller;
3876 unsigned long flags;
3878 ret = __spi_validate(spi, message);
3882 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3884 ret = __spi_async(spi, message);
3886 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3891 EXPORT_SYMBOL_GPL(spi_async_locked);
3893 /*-------------------------------------------------------------------------*/
3895 /* Utility methods for SPI protocol drivers, layered on
3896 * top of the core. Some other utility methods are defined as
3900 static void spi_complete(void *arg)
3905 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3907 DECLARE_COMPLETION_ONSTACK(done);
3909 struct spi_controller *ctlr = spi->controller;
3910 unsigned long flags;
3912 status = __spi_validate(spi, message);
3916 message->complete = spi_complete;
3917 message->context = &done;
3920 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3921 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3923 /* If we're not using the legacy transfer method then we will
3924 * try to transfer in the calling context so special case.
3925 * This code would be less tricky if we could remove the
3926 * support for driver implemented message queues.
3928 if (ctlr->transfer == spi_queued_transfer) {
3929 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3931 trace_spi_message_submit(message);
3933 status = __spi_queued_transfer(spi, message, false);
3935 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3937 status = spi_async_locked(spi, message);
3941 /* Push out the messages in the calling context if we
3944 if (ctlr->transfer == spi_queued_transfer) {
3945 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3946 spi_sync_immediate);
3947 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3948 spi_sync_immediate);
3949 __spi_pump_messages(ctlr, false);
3952 wait_for_completion(&done);
3953 status = message->status;
3955 message->context = NULL;
3960 * spi_sync - blocking/synchronous SPI data transfers
3961 * @spi: device with which data will be exchanged
3962 * @message: describes the data transfers
3963 * Context: can sleep
3965 * This call may only be used from a context that may sleep. The sleep
3966 * is non-interruptible, and has no timeout. Low-overhead controller
3967 * drivers may DMA directly into and out of the message buffers.
3969 * Note that the SPI device's chip select is active during the message,
3970 * and then is normally disabled between messages. Drivers for some
3971 * frequently-used devices may want to minimize costs of selecting a chip,
3972 * by leaving it selected in anticipation that the next message will go
3973 * to the same chip. (That may increase power usage.)
3975 * Also, the caller is guaranteeing that the memory associated with the
3976 * message will not be freed before this call returns.
3978 * Return: zero on success, else a negative error code.
3980 int spi_sync(struct spi_device *spi, struct spi_message *message)
3984 mutex_lock(&spi->controller->bus_lock_mutex);
3985 ret = __spi_sync(spi, message);
3986 mutex_unlock(&spi->controller->bus_lock_mutex);
3990 EXPORT_SYMBOL_GPL(spi_sync);
3993 * spi_sync_locked - version of spi_sync with exclusive bus usage
3994 * @spi: device with which data will be exchanged
3995 * @message: describes the data transfers
3996 * Context: can sleep
3998 * This call may only be used from a context that may sleep. The sleep
3999 * is non-interruptible, and has no timeout. Low-overhead controller
4000 * drivers may DMA directly into and out of the message buffers.
4002 * This call should be used by drivers that require exclusive access to the
4003 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
4004 * be released by a spi_bus_unlock call when the exclusive access is over.
4006 * Return: zero on success, else a negative error code.
4008 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
4010 return __spi_sync(spi, message);
4012 EXPORT_SYMBOL_GPL(spi_sync_locked);
4015 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
4016 * @ctlr: SPI bus master that should be locked for exclusive bus access
4017 * Context: can sleep
4019 * This call may only be used from a context that may sleep. The sleep
4020 * is non-interruptible, and has no timeout.
4022 * This call should be used by drivers that require exclusive access to the
4023 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
4024 * exclusive access is over. Data transfer must be done by spi_sync_locked
4025 * and spi_async_locked calls when the SPI bus lock is held.
4027 * Return: always zero.
4029 int spi_bus_lock(struct spi_controller *ctlr)
4031 unsigned long flags;
4033 mutex_lock(&ctlr->bus_lock_mutex);
4035 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
4036 ctlr->bus_lock_flag = 1;
4037 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
4039 /* mutex remains locked until spi_bus_unlock is called */
4043 EXPORT_SYMBOL_GPL(spi_bus_lock);
4046 * spi_bus_unlock - release the lock for exclusive SPI bus usage
4047 * @ctlr: SPI bus master that was locked for exclusive bus access
4048 * Context: can sleep
4050 * This call may only be used from a context that may sleep. The sleep
4051 * is non-interruptible, and has no timeout.
4053 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
4056 * Return: always zero.
4058 int spi_bus_unlock(struct spi_controller *ctlr)
4060 ctlr->bus_lock_flag = 0;
4062 mutex_unlock(&ctlr->bus_lock_mutex);
4066 EXPORT_SYMBOL_GPL(spi_bus_unlock);
4068 /* portable code must never pass more than 32 bytes */
4069 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
4074 * spi_write_then_read - SPI synchronous write followed by read
4075 * @spi: device with which data will be exchanged
4076 * @txbuf: data to be written (need not be dma-safe)
4077 * @n_tx: size of txbuf, in bytes
4078 * @rxbuf: buffer into which data will be read (need not be dma-safe)
4079 * @n_rx: size of rxbuf, in bytes
4080 * Context: can sleep
4082 * This performs a half duplex MicroWire style transaction with the
4083 * device, sending txbuf and then reading rxbuf. The return value
4084 * is zero for success, else a negative errno status code.
4085 * This call may only be used from a context that may sleep.
4087 * Parameters to this routine are always copied using a small buffer.
4088 * Performance-sensitive or bulk transfer code should instead use
4089 * spi_{async,sync}() calls with dma-safe buffers.
4091 * Return: zero on success, else a negative error code.
4093 int spi_write_then_read(struct spi_device *spi,
4094 const void *txbuf, unsigned n_tx,
4095 void *rxbuf, unsigned n_rx)
4097 static DEFINE_MUTEX(lock);
4100 struct spi_message message;
4101 struct spi_transfer x[2];
4104 /* Use preallocated DMA-safe buffer if we can. We can't avoid
4105 * copying here, (as a pure convenience thing), but we can
4106 * keep heap costs out of the hot path unless someone else is
4107 * using the pre-allocated buffer or the transfer is too large.
4109 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
4110 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
4111 GFP_KERNEL | GFP_DMA);
4118 spi_message_init(&message);
4119 memset(x, 0, sizeof(x));
4122 spi_message_add_tail(&x[0], &message);
4126 spi_message_add_tail(&x[1], &message);
4129 memcpy(local_buf, txbuf, n_tx);
4130 x[0].tx_buf = local_buf;
4131 x[1].rx_buf = local_buf + n_tx;
4134 status = spi_sync(spi, &message);
4136 memcpy(rxbuf, x[1].rx_buf, n_rx);
4138 if (x[0].tx_buf == buf)
4139 mutex_unlock(&lock);
4145 EXPORT_SYMBOL_GPL(spi_write_then_read);
4147 /*-------------------------------------------------------------------------*/
4149 #if IS_ENABLED(CONFIG_OF)
4150 /* must call put_device() when done with returned spi_device device */
4151 struct spi_device *of_find_spi_device_by_node(struct device_node *node)
4153 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
4155 return dev ? to_spi_device(dev) : NULL;
4157 EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
4158 #endif /* IS_ENABLED(CONFIG_OF) */
4160 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
4161 /* the spi controllers are not using spi_bus, so we find it with another way */
4162 static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
4166 dev = class_find_device_by_of_node(&spi_master_class, node);
4167 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4168 dev = class_find_device_by_of_node(&spi_slave_class, node);
4172 /* reference got in class_find_device */
4173 return container_of(dev, struct spi_controller, dev);
4176 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
4179 struct of_reconfig_data *rd = arg;
4180 struct spi_controller *ctlr;
4181 struct spi_device *spi;
4183 switch (of_reconfig_get_state_change(action, arg)) {
4184 case OF_RECONFIG_CHANGE_ADD:
4185 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
4187 return NOTIFY_OK; /* not for us */
4189 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
4190 put_device(&ctlr->dev);
4194 spi = of_register_spi_device(ctlr, rd->dn);
4195 put_device(&ctlr->dev);
4198 pr_err("%s: failed to create for '%pOF'\n",
4200 of_node_clear_flag(rd->dn, OF_POPULATED);
4201 return notifier_from_errno(PTR_ERR(spi));
4205 case OF_RECONFIG_CHANGE_REMOVE:
4206 /* already depopulated? */
4207 if (!of_node_check_flag(rd->dn, OF_POPULATED))
4210 /* find our device by node */
4211 spi = of_find_spi_device_by_node(rd->dn);
4213 return NOTIFY_OK; /* no? not meant for us */
4215 /* unregister takes one ref away */
4216 spi_unregister_device(spi);
4218 /* and put the reference of the find */
4219 put_device(&spi->dev);
4226 static struct notifier_block spi_of_notifier = {
4227 .notifier_call = of_spi_notify,
4229 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4230 extern struct notifier_block spi_of_notifier;
4231 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4233 #if IS_ENABLED(CONFIG_ACPI)
4234 static int spi_acpi_controller_match(struct device *dev, const void *data)
4236 return ACPI_COMPANION(dev->parent) == data;
4239 static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4243 dev = class_find_device(&spi_master_class, NULL, adev,
4244 spi_acpi_controller_match);
4245 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4246 dev = class_find_device(&spi_slave_class, NULL, adev,
4247 spi_acpi_controller_match);
4251 return container_of(dev, struct spi_controller, dev);
4254 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4258 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4259 return to_spi_device(dev);
4262 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4265 struct acpi_device *adev = arg;
4266 struct spi_controller *ctlr;
4267 struct spi_device *spi;
4270 case ACPI_RECONFIG_DEVICE_ADD:
4271 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
4275 acpi_register_spi_device(ctlr, adev);
4276 put_device(&ctlr->dev);
4278 case ACPI_RECONFIG_DEVICE_REMOVE:
4279 if (!acpi_device_enumerated(adev))
4282 spi = acpi_spi_find_device_by_adev(adev);
4286 spi_unregister_device(spi);
4287 put_device(&spi->dev);
4294 static struct notifier_block spi_acpi_notifier = {
4295 .notifier_call = acpi_spi_notify,
4298 extern struct notifier_block spi_acpi_notifier;
4301 static int __init spi_init(void)
4305 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4311 status = bus_register(&spi_bus_type);
4315 status = class_register(&spi_master_class);
4319 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4320 status = class_register(&spi_slave_class);
4325 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4326 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4327 if (IS_ENABLED(CONFIG_ACPI))
4328 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4333 class_unregister(&spi_master_class);
4335 bus_unregister(&spi_bus_type);
4343 /* board_info is normally registered in arch_initcall(),
4344 * but even essential drivers wait till later
4346 * REVISIT only boardinfo really needs static linking. the rest (device and
4347 * driver registration) _could_ be dynamically linked (modular) ... costs
4348 * include needing to have boardinfo data structures be much more public.
4350 postcore_initcall(spi_init);