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;
454 return driver_register(&sdrv->driver);
456 EXPORT_SYMBOL_GPL(__spi_register_driver);
458 /*-------------------------------------------------------------------------*/
460 /* SPI devices should normally not be created by SPI device drivers; that
461 * would make them board-specific. Similarly with SPI controller drivers.
462 * Device registration normally goes into like arch/.../mach.../board-YYY.c
463 * with other readonly (flashable) information about mainboard devices.
467 struct list_head list;
468 struct spi_board_info board_info;
471 static LIST_HEAD(board_list);
472 static LIST_HEAD(spi_controller_list);
475 * Used to protect add/del operation for board_info list and
476 * spi_controller list, and their matching process
477 * also used to protect object of type struct idr
479 static DEFINE_MUTEX(board_lock);
482 * Prevents addition of devices with same chip select and
483 * addition of devices below an unregistering controller.
485 static DEFINE_MUTEX(spi_add_lock);
488 * spi_alloc_device - Allocate a new SPI device
489 * @ctlr: Controller to which device is connected
492 * Allows a driver to allocate and initialize a spi_device without
493 * registering it immediately. This allows a driver to directly
494 * fill the spi_device with device parameters before calling
495 * spi_add_device() on it.
497 * Caller is responsible to call spi_add_device() on the returned
498 * spi_device structure to add it to the SPI controller. If the caller
499 * needs to discard the spi_device without adding it, then it should
500 * call spi_dev_put() on it.
502 * Return: a pointer to the new device, or NULL.
504 struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
506 struct spi_device *spi;
508 if (!spi_controller_get(ctlr))
511 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
513 spi_controller_put(ctlr);
517 spi->master = spi->controller = ctlr;
518 spi->dev.parent = &ctlr->dev;
519 spi->dev.bus = &spi_bus_type;
520 spi->dev.release = spidev_release;
521 spi->cs_gpio = -ENOENT;
522 spi->mode = ctlr->buswidth_override_bits;
524 spin_lock_init(&spi->statistics.lock);
526 device_initialize(&spi->dev);
529 EXPORT_SYMBOL_GPL(spi_alloc_device);
531 static void spi_dev_set_name(struct spi_device *spi)
533 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
536 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
540 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
544 static int spi_dev_check(struct device *dev, void *data)
546 struct spi_device *spi = to_spi_device(dev);
547 struct spi_device *new_spi = data;
549 if (spi->controller == new_spi->controller &&
550 spi->chip_select == new_spi->chip_select)
555 static void spi_cleanup(struct spi_device *spi)
557 if (spi->controller->cleanup)
558 spi->controller->cleanup(spi);
561 static int __spi_add_device(struct spi_device *spi)
563 struct spi_controller *ctlr = spi->controller;
564 struct device *dev = ctlr->dev.parent;
567 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
569 dev_err(dev, "chipselect %d already in use\n",
574 /* Controller may unregister concurrently */
575 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
576 !device_is_registered(&ctlr->dev)) {
580 /* Descriptors take precedence */
582 spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
583 else if (ctlr->cs_gpios)
584 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
586 /* Drivers may modify this initial i/o setup, but will
587 * normally rely on the device being setup. Devices
588 * using SPI_CS_HIGH can't coexist well otherwise...
590 status = spi_setup(spi);
592 dev_err(dev, "can't setup %s, status %d\n",
593 dev_name(&spi->dev), status);
597 /* Device may be bound to an active driver when this returns */
598 status = device_add(&spi->dev);
600 dev_err(dev, "can't add %s, status %d\n",
601 dev_name(&spi->dev), status);
604 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
611 * spi_add_device - Add spi_device allocated with spi_alloc_device
612 * @spi: spi_device to register
614 * Companion function to spi_alloc_device. Devices allocated with
615 * spi_alloc_device can be added onto the spi bus with this function.
617 * Return: 0 on success; negative errno on failure
619 int spi_add_device(struct spi_device *spi)
621 struct spi_controller *ctlr = spi->controller;
622 struct device *dev = ctlr->dev.parent;
625 /* Chipselects are numbered 0..max; validate. */
626 if (spi->chip_select >= ctlr->num_chipselect) {
627 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
628 ctlr->num_chipselect);
632 /* Set the bus ID string */
633 spi_dev_set_name(spi);
635 /* We need to make sure there's no other device with this
636 * chipselect **BEFORE** we call setup(), else we'll trash
637 * its configuration. Lock against concurrent add() calls.
639 mutex_lock(&spi_add_lock);
640 status = __spi_add_device(spi);
641 mutex_unlock(&spi_add_lock);
644 EXPORT_SYMBOL_GPL(spi_add_device);
646 static int spi_add_device_locked(struct spi_device *spi)
648 struct spi_controller *ctlr = spi->controller;
649 struct device *dev = ctlr->dev.parent;
651 /* Chipselects are numbered 0..max; validate. */
652 if (spi->chip_select >= ctlr->num_chipselect) {
653 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
654 ctlr->num_chipselect);
658 /* Set the bus ID string */
659 spi_dev_set_name(spi);
661 WARN_ON(!mutex_is_locked(&spi_add_lock));
662 return __spi_add_device(spi);
666 * spi_new_device - instantiate one new SPI device
667 * @ctlr: Controller to which device is connected
668 * @chip: Describes the SPI device
671 * On typical mainboards, this is purely internal; and it's not needed
672 * after board init creates the hard-wired devices. Some development
673 * platforms may not be able to use spi_register_board_info though, and
674 * this is exported so that for example a USB or parport based adapter
675 * driver could add devices (which it would learn about out-of-band).
677 * Return: the new device, or NULL.
679 struct spi_device *spi_new_device(struct spi_controller *ctlr,
680 struct spi_board_info *chip)
682 struct spi_device *proxy;
685 /* NOTE: caller did any chip->bus_num checks necessary.
687 * Also, unless we change the return value convention to use
688 * error-or-pointer (not NULL-or-pointer), troubleshootability
689 * suggests syslogged diagnostics are best here (ugh).
692 proxy = spi_alloc_device(ctlr);
696 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
698 proxy->chip_select = chip->chip_select;
699 proxy->max_speed_hz = chip->max_speed_hz;
700 proxy->mode = chip->mode;
701 proxy->irq = chip->irq;
702 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
703 proxy->dev.platform_data = (void *) chip->platform_data;
704 proxy->controller_data = chip->controller_data;
705 proxy->controller_state = NULL;
708 status = device_add_software_node(&proxy->dev, chip->swnode);
710 dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n",
711 chip->modalias, status);
716 status = spi_add_device(proxy);
723 device_remove_software_node(&proxy->dev);
727 EXPORT_SYMBOL_GPL(spi_new_device);
730 * spi_unregister_device - unregister a single SPI device
731 * @spi: spi_device to unregister
733 * Start making the passed SPI device vanish. Normally this would be handled
734 * by spi_unregister_controller().
736 void spi_unregister_device(struct spi_device *spi)
741 if (spi->dev.of_node) {
742 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
743 of_node_put(spi->dev.of_node);
745 if (ACPI_COMPANION(&spi->dev))
746 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
747 device_remove_software_node(&spi->dev);
748 device_del(&spi->dev);
750 put_device(&spi->dev);
752 EXPORT_SYMBOL_GPL(spi_unregister_device);
754 static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
755 struct spi_board_info *bi)
757 struct spi_device *dev;
759 if (ctlr->bus_num != bi->bus_num)
762 dev = spi_new_device(ctlr, bi);
764 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
769 * spi_register_board_info - register SPI devices for a given board
770 * @info: array of chip descriptors
771 * @n: how many descriptors are provided
774 * Board-specific early init code calls this (probably during arch_initcall)
775 * with segments of the SPI device table. Any device nodes are created later,
776 * after the relevant parent SPI controller (bus_num) is defined. We keep
777 * this table of devices forever, so that reloading a controller driver will
778 * not make Linux forget about these hard-wired devices.
780 * Other code can also call this, e.g. a particular add-on board might provide
781 * SPI devices through its expansion connector, so code initializing that board
782 * would naturally declare its SPI devices.
784 * The board info passed can safely be __initdata ... but be careful of
785 * any embedded pointers (platform_data, etc), they're copied as-is.
787 * Return: zero on success, else a negative error code.
789 int spi_register_board_info(struct spi_board_info const *info, unsigned n)
791 struct boardinfo *bi;
797 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
801 for (i = 0; i < n; i++, bi++, info++) {
802 struct spi_controller *ctlr;
804 memcpy(&bi->board_info, info, sizeof(*info));
806 mutex_lock(&board_lock);
807 list_add_tail(&bi->list, &board_list);
808 list_for_each_entry(ctlr, &spi_controller_list, list)
809 spi_match_controller_to_boardinfo(ctlr,
811 mutex_unlock(&board_lock);
817 /*-------------------------------------------------------------------------*/
819 static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
821 bool activate = enable;
824 * Avoid calling into the driver (or doing delays) if the chip select
825 * isn't actually changing from the last time this was called.
827 if (!force && (spi->controller->last_cs_enable == enable) &&
828 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
831 trace_spi_set_cs(spi, activate);
833 spi->controller->last_cs_enable = enable;
834 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
836 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
837 !spi->controller->set_cs_timing) {
839 spi_delay_exec(&spi->cs_setup, NULL);
841 spi_delay_exec(&spi->cs_hold, NULL);
844 if (spi->mode & SPI_CS_HIGH)
847 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
848 if (!(spi->mode & SPI_NO_CS)) {
851 * Historically ACPI has no means of the GPIO polarity and
852 * thus the SPISerialBus() resource defines it on the per-chip
853 * basis. In order to avoid a chain of negations, the GPIO
854 * polarity is considered being Active High. Even for the cases
855 * when _DSD() is involved (in the updated versions of ACPI)
856 * the GPIO CS polarity must be defined Active High to avoid
857 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
860 if (has_acpi_companion(&spi->dev))
861 gpiod_set_value_cansleep(spi->cs_gpiod, !enable);
863 /* Polarity handled by GPIO library */
864 gpiod_set_value_cansleep(spi->cs_gpiod, activate);
867 * invert the enable line, as active low is
870 gpio_set_value_cansleep(spi->cs_gpio, !enable);
873 /* Some SPI masters need both GPIO CS & slave_select */
874 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
875 spi->controller->set_cs)
876 spi->controller->set_cs(spi, !enable);
877 } else if (spi->controller->set_cs) {
878 spi->controller->set_cs(spi, !enable);
881 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
882 !spi->controller->set_cs_timing) {
884 spi_delay_exec(&spi->cs_inactive, NULL);
888 #ifdef CONFIG_HAS_DMA
889 int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
890 struct sg_table *sgt, void *buf, size_t len,
891 enum dma_data_direction dir)
893 const bool vmalloced_buf = is_vmalloc_addr(buf);
894 unsigned int max_seg_size = dma_get_max_seg_size(dev);
895 #ifdef CONFIG_HIGHMEM
896 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
897 (unsigned long)buf < (PKMAP_BASE +
898 (LAST_PKMAP * PAGE_SIZE)));
900 const bool kmap_buf = false;
904 struct page *vm_page;
905 struct scatterlist *sg;
910 if (vmalloced_buf || kmap_buf) {
911 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
912 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
913 } else if (virt_addr_valid(buf)) {
914 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
915 sgs = DIV_ROUND_UP(len, desc_len);
920 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
925 for (i = 0; i < sgs; i++) {
927 if (vmalloced_buf || kmap_buf) {
929 * Next scatterlist entry size is the minimum between
930 * the desc_len and the remaining buffer length that
933 min = min_t(size_t, desc_len,
935 PAGE_SIZE - offset_in_page(buf)));
937 vm_page = vmalloc_to_page(buf);
939 vm_page = kmap_to_page(buf);
944 sg_set_page(sg, vm_page,
945 min, offset_in_page(buf));
947 min = min_t(size_t, len, desc_len);
949 sg_set_buf(sg, sg_buf, min);
957 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
970 void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
971 struct sg_table *sgt, enum dma_data_direction dir)
973 if (sgt->orig_nents) {
974 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
979 static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
981 struct device *tx_dev, *rx_dev;
982 struct spi_transfer *xfer;
989 tx_dev = ctlr->dma_tx->device->dev;
990 else if (ctlr->dma_map_dev)
991 tx_dev = ctlr->dma_map_dev;
993 tx_dev = ctlr->dev.parent;
996 rx_dev = ctlr->dma_rx->device->dev;
997 else if (ctlr->dma_map_dev)
998 rx_dev = ctlr->dma_map_dev;
1000 rx_dev = ctlr->dev.parent;
1002 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1003 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1006 if (xfer->tx_buf != NULL) {
1007 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
1008 (void *)xfer->tx_buf, xfer->len,
1014 if (xfer->rx_buf != NULL) {
1015 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
1016 xfer->rx_buf, xfer->len,
1019 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
1026 ctlr->cur_msg_mapped = true;
1031 static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
1033 struct spi_transfer *xfer;
1034 struct device *tx_dev, *rx_dev;
1036 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
1040 tx_dev = ctlr->dma_tx->device->dev;
1042 tx_dev = ctlr->dev.parent;
1045 rx_dev = ctlr->dma_rx->device->dev;
1047 rx_dev = ctlr->dev.parent;
1049 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1050 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1053 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1054 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1057 ctlr->cur_msg_mapped = false;
1061 #else /* !CONFIG_HAS_DMA */
1062 static inline int __spi_map_msg(struct spi_controller *ctlr,
1063 struct spi_message *msg)
1068 static inline int __spi_unmap_msg(struct spi_controller *ctlr,
1069 struct spi_message *msg)
1073 #endif /* !CONFIG_HAS_DMA */
1075 static inline int spi_unmap_msg(struct spi_controller *ctlr,
1076 struct spi_message *msg)
1078 struct spi_transfer *xfer;
1080 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1082 * Restore the original value of tx_buf or rx_buf if they are
1085 if (xfer->tx_buf == ctlr->dummy_tx)
1086 xfer->tx_buf = NULL;
1087 if (xfer->rx_buf == ctlr->dummy_rx)
1088 xfer->rx_buf = NULL;
1091 return __spi_unmap_msg(ctlr, msg);
1094 static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1096 struct spi_transfer *xfer;
1098 unsigned int max_tx, max_rx;
1100 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1101 && !(msg->spi->mode & SPI_3WIRE)) {
1105 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1106 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1108 max_tx = max(xfer->len, max_tx);
1109 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1111 max_rx = max(xfer->len, max_rx);
1115 tmp = krealloc(ctlr->dummy_tx, max_tx,
1116 GFP_KERNEL | GFP_DMA);
1119 ctlr->dummy_tx = tmp;
1120 memset(tmp, 0, max_tx);
1124 tmp = krealloc(ctlr->dummy_rx, max_rx,
1125 GFP_KERNEL | GFP_DMA);
1128 ctlr->dummy_rx = tmp;
1131 if (max_tx || max_rx) {
1132 list_for_each_entry(xfer, &msg->transfers,
1137 xfer->tx_buf = ctlr->dummy_tx;
1139 xfer->rx_buf = ctlr->dummy_rx;
1144 return __spi_map_msg(ctlr, msg);
1147 static int spi_transfer_wait(struct spi_controller *ctlr,
1148 struct spi_message *msg,
1149 struct spi_transfer *xfer)
1151 struct spi_statistics *statm = &ctlr->statistics;
1152 struct spi_statistics *stats = &msg->spi->statistics;
1153 u32 speed_hz = xfer->speed_hz;
1154 unsigned long long ms;
1156 if (spi_controller_is_slave(ctlr)) {
1157 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1158 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1166 * For each byte we wait for 8 cycles of the SPI clock.
1167 * Since speed is defined in Hz and we want milliseconds,
1168 * use respective multiplier, but before the division,
1169 * otherwise we may get 0 for short transfers.
1171 ms = 8LL * MSEC_PER_SEC * xfer->len;
1172 do_div(ms, speed_hz);
1175 * Increase it twice and add 200 ms tolerance, use
1176 * predefined maximum in case of overflow.
1182 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1183 msecs_to_jiffies(ms));
1186 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1187 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1188 dev_err(&msg->spi->dev,
1189 "SPI transfer timed out\n");
1197 static void _spi_transfer_delay_ns(u32 ns)
1201 if (ns <= NSEC_PER_USEC) {
1204 u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC);
1209 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1213 int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1215 u32 delay = _delay->value;
1216 u32 unit = _delay->unit;
1223 case SPI_DELAY_UNIT_USECS:
1224 delay *= NSEC_PER_USEC;
1226 case SPI_DELAY_UNIT_NSECS:
1227 /* Nothing to do here */
1229 case SPI_DELAY_UNIT_SCK:
1230 /* clock cycles need to be obtained from spi_transfer */
1234 * If there is unknown effective speed, approximate it
1235 * by underestimating with half of the requested hz.
1237 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1241 /* Convert delay to nanoseconds */
1242 delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz);
1250 EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1252 int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1261 delay = spi_delay_to_ns(_delay, xfer);
1265 _spi_transfer_delay_ns(delay);
1269 EXPORT_SYMBOL_GPL(spi_delay_exec);
1271 static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1272 struct spi_transfer *xfer)
1274 u32 default_delay_ns = 10 * NSEC_PER_USEC;
1275 u32 delay = xfer->cs_change_delay.value;
1276 u32 unit = xfer->cs_change_delay.unit;
1279 /* return early on "fast" mode - for everything but USECS */
1281 if (unit == SPI_DELAY_UNIT_USECS)
1282 _spi_transfer_delay_ns(default_delay_ns);
1286 ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1288 dev_err_once(&msg->spi->dev,
1289 "Use of unsupported delay unit %i, using default of %luus\n",
1290 unit, default_delay_ns / NSEC_PER_USEC);
1291 _spi_transfer_delay_ns(default_delay_ns);
1296 * spi_transfer_one_message - Default implementation of transfer_one_message()
1298 * This is a standard implementation of transfer_one_message() for
1299 * drivers which implement a transfer_one() operation. It provides
1300 * standard handling of delays and chip select management.
1302 static int spi_transfer_one_message(struct spi_controller *ctlr,
1303 struct spi_message *msg)
1305 struct spi_transfer *xfer;
1306 bool keep_cs = false;
1308 struct spi_statistics *statm = &ctlr->statistics;
1309 struct spi_statistics *stats = &msg->spi->statistics;
1311 spi_set_cs(msg->spi, true, false);
1313 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1314 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1316 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1317 trace_spi_transfer_start(msg, xfer);
1319 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1320 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1322 if (!ctlr->ptp_sts_supported) {
1323 xfer->ptp_sts_word_pre = 0;
1324 ptp_read_system_prets(xfer->ptp_sts);
1327 if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) {
1328 reinit_completion(&ctlr->xfer_completion);
1331 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1333 if (ctlr->cur_msg_mapped &&
1334 (xfer->error & SPI_TRANS_FAIL_NO_START)) {
1335 __spi_unmap_msg(ctlr, msg);
1336 ctlr->fallback = true;
1337 xfer->error &= ~SPI_TRANS_FAIL_NO_START;
1341 SPI_STATISTICS_INCREMENT_FIELD(statm,
1343 SPI_STATISTICS_INCREMENT_FIELD(stats,
1345 dev_err(&msg->spi->dev,
1346 "SPI transfer failed: %d\n", ret);
1351 ret = spi_transfer_wait(ctlr, msg, xfer);
1357 dev_err(&msg->spi->dev,
1358 "Bufferless transfer has length %u\n",
1362 if (!ctlr->ptp_sts_supported) {
1363 ptp_read_system_postts(xfer->ptp_sts);
1364 xfer->ptp_sts_word_post = xfer->len;
1367 trace_spi_transfer_stop(msg, xfer);
1369 if (msg->status != -EINPROGRESS)
1372 spi_transfer_delay_exec(xfer);
1374 if (xfer->cs_change) {
1375 if (list_is_last(&xfer->transfer_list,
1379 spi_set_cs(msg->spi, false, false);
1380 _spi_transfer_cs_change_delay(msg, xfer);
1381 spi_set_cs(msg->spi, true, false);
1385 msg->actual_length += xfer->len;
1389 if (ret != 0 || !keep_cs)
1390 spi_set_cs(msg->spi, false, false);
1392 if (msg->status == -EINPROGRESS)
1395 if (msg->status && ctlr->handle_err)
1396 ctlr->handle_err(ctlr, msg);
1398 spi_finalize_current_message(ctlr);
1404 * spi_finalize_current_transfer - report completion of a transfer
1405 * @ctlr: the controller reporting completion
1407 * Called by SPI drivers using the core transfer_one_message()
1408 * implementation to notify it that the current interrupt driven
1409 * transfer has finished and the next one may be scheduled.
1411 void spi_finalize_current_transfer(struct spi_controller *ctlr)
1413 complete(&ctlr->xfer_completion);
1415 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1417 static void spi_idle_runtime_pm(struct spi_controller *ctlr)
1419 if (ctlr->auto_runtime_pm) {
1420 pm_runtime_mark_last_busy(ctlr->dev.parent);
1421 pm_runtime_put_autosuspend(ctlr->dev.parent);
1426 * __spi_pump_messages - function which processes spi message queue
1427 * @ctlr: controller to process queue for
1428 * @in_kthread: true if we are in the context of the message pump thread
1430 * This function checks if there is any spi message in the queue that
1431 * needs processing and if so call out to the driver to initialize hardware
1432 * and transfer each message.
1434 * Note that it is called both from the kthread itself and also from
1435 * inside spi_sync(); the queue extraction handling at the top of the
1436 * function should deal with this safely.
1438 static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1440 struct spi_transfer *xfer;
1441 struct spi_message *msg;
1442 bool was_busy = false;
1443 unsigned long flags;
1447 spin_lock_irqsave(&ctlr->queue_lock, flags);
1449 /* Make sure we are not already running a message */
1450 if (ctlr->cur_msg) {
1451 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1455 /* If another context is idling the device then defer */
1457 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1458 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1462 /* Check if the queue is idle */
1463 if (list_empty(&ctlr->queue) || !ctlr->running) {
1465 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1469 /* Defer any non-atomic teardown to the thread */
1471 if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
1472 !ctlr->unprepare_transfer_hardware) {
1473 spi_idle_runtime_pm(ctlr);
1475 trace_spi_controller_idle(ctlr);
1477 kthread_queue_work(ctlr->kworker,
1478 &ctlr->pump_messages);
1480 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1485 ctlr->idling = true;
1486 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1488 kfree(ctlr->dummy_rx);
1489 ctlr->dummy_rx = NULL;
1490 kfree(ctlr->dummy_tx);
1491 ctlr->dummy_tx = NULL;
1492 if (ctlr->unprepare_transfer_hardware &&
1493 ctlr->unprepare_transfer_hardware(ctlr))
1495 "failed to unprepare transfer hardware\n");
1496 spi_idle_runtime_pm(ctlr);
1497 trace_spi_controller_idle(ctlr);
1499 spin_lock_irqsave(&ctlr->queue_lock, flags);
1500 ctlr->idling = false;
1501 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1505 /* Extract head of queue */
1506 msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1507 ctlr->cur_msg = msg;
1509 list_del_init(&msg->queue);
1514 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1516 mutex_lock(&ctlr->io_mutex);
1518 if (!was_busy && ctlr->auto_runtime_pm) {
1519 ret = pm_runtime_get_sync(ctlr->dev.parent);
1521 pm_runtime_put_noidle(ctlr->dev.parent);
1522 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1524 mutex_unlock(&ctlr->io_mutex);
1530 trace_spi_controller_busy(ctlr);
1532 if (!was_busy && ctlr->prepare_transfer_hardware) {
1533 ret = ctlr->prepare_transfer_hardware(ctlr);
1536 "failed to prepare transfer hardware: %d\n",
1539 if (ctlr->auto_runtime_pm)
1540 pm_runtime_put(ctlr->dev.parent);
1543 spi_finalize_current_message(ctlr);
1545 mutex_unlock(&ctlr->io_mutex);
1550 trace_spi_message_start(msg);
1552 if (ctlr->prepare_message) {
1553 ret = ctlr->prepare_message(ctlr, msg);
1555 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1558 spi_finalize_current_message(ctlr);
1561 ctlr->cur_msg_prepared = true;
1564 ret = spi_map_msg(ctlr, msg);
1567 spi_finalize_current_message(ctlr);
1571 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1572 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1573 xfer->ptp_sts_word_pre = 0;
1574 ptp_read_system_prets(xfer->ptp_sts);
1578 ret = ctlr->transfer_one_message(ctlr, msg);
1581 "failed to transfer one message from queue\n");
1586 mutex_unlock(&ctlr->io_mutex);
1588 /* Prod the scheduler in case transfer_one() was busy waiting */
1594 * spi_pump_messages - kthread work function which processes spi message queue
1595 * @work: pointer to kthread work struct contained in the controller struct
1597 static void spi_pump_messages(struct kthread_work *work)
1599 struct spi_controller *ctlr =
1600 container_of(work, struct spi_controller, pump_messages);
1602 __spi_pump_messages(ctlr, true);
1606 * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
1607 * TX timestamp for the requested byte from the SPI
1608 * transfer. The frequency with which this function
1609 * must be called (once per word, once for the whole
1610 * transfer, once per batch of words etc) is arbitrary
1611 * as long as the @tx buffer offset is greater than or
1612 * equal to the requested byte at the time of the
1613 * call. The timestamp is only taken once, at the
1614 * first such call. It is assumed that the driver
1615 * advances its @tx buffer pointer monotonically.
1616 * @ctlr: Pointer to the spi_controller structure of the driver
1617 * @xfer: Pointer to the transfer being timestamped
1618 * @progress: How many words (not bytes) have been transferred so far
1619 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1620 * transfer, for less jitter in time measurement. Only compatible
1621 * with PIO drivers. If true, must follow up with
1622 * spi_take_timestamp_post or otherwise system will crash.
1623 * WARNING: for fully predictable results, the CPU frequency must
1624 * also be under control (governor).
1626 void spi_take_timestamp_pre(struct spi_controller *ctlr,
1627 struct spi_transfer *xfer,
1628 size_t progress, bool irqs_off)
1633 if (xfer->timestamped)
1636 if (progress > xfer->ptp_sts_word_pre)
1639 /* Capture the resolution of the timestamp */
1640 xfer->ptp_sts_word_pre = progress;
1643 local_irq_save(ctlr->irq_flags);
1647 ptp_read_system_prets(xfer->ptp_sts);
1649 EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
1652 * spi_take_timestamp_post - helper for drivers to collect the end of the
1653 * TX timestamp for the requested byte from the SPI
1654 * transfer. Can be called with an arbitrary
1655 * frequency: only the first call where @tx exceeds
1656 * or is equal to the requested word will be
1658 * @ctlr: Pointer to the spi_controller structure of the driver
1659 * @xfer: Pointer to the transfer being timestamped
1660 * @progress: How many words (not bytes) have been transferred so far
1661 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1663 void spi_take_timestamp_post(struct spi_controller *ctlr,
1664 struct spi_transfer *xfer,
1665 size_t progress, bool irqs_off)
1670 if (xfer->timestamped)
1673 if (progress < xfer->ptp_sts_word_post)
1676 ptp_read_system_postts(xfer->ptp_sts);
1679 local_irq_restore(ctlr->irq_flags);
1683 /* Capture the resolution of the timestamp */
1684 xfer->ptp_sts_word_post = progress;
1686 xfer->timestamped = true;
1688 EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
1691 * spi_set_thread_rt - set the controller to pump at realtime priority
1692 * @ctlr: controller to boost priority of
1694 * This can be called because the controller requested realtime priority
1695 * (by setting the ->rt value before calling spi_register_controller()) or
1696 * because a device on the bus said that its transfers needed realtime
1699 * NOTE: at the moment if any device on a bus says it needs realtime then
1700 * the thread will be at realtime priority for all transfers on that
1701 * controller. If this eventually becomes a problem we may see if we can
1702 * find a way to boost the priority only temporarily during relevant
1705 static void spi_set_thread_rt(struct spi_controller *ctlr)
1707 dev_info(&ctlr->dev,
1708 "will run message pump with realtime priority\n");
1709 sched_set_fifo(ctlr->kworker->task);
1712 static int spi_init_queue(struct spi_controller *ctlr)
1714 ctlr->running = false;
1717 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
1718 if (IS_ERR(ctlr->kworker)) {
1719 dev_err(&ctlr->dev, "failed to create message pump kworker\n");
1720 return PTR_ERR(ctlr->kworker);
1723 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1726 * Controller config will indicate if this controller should run the
1727 * message pump with high (realtime) priority to reduce the transfer
1728 * latency on the bus by minimising the delay between a transfer
1729 * request and the scheduling of the message pump thread. Without this
1730 * setting the message pump thread will remain at default priority.
1733 spi_set_thread_rt(ctlr);
1739 * spi_get_next_queued_message() - called by driver to check for queued
1741 * @ctlr: the controller to check for queued messages
1743 * If there are more messages in the queue, the next message is returned from
1746 * Return: the next message in the queue, else NULL if the queue is empty.
1748 struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1750 struct spi_message *next;
1751 unsigned long flags;
1753 /* get a pointer to the next message, if any */
1754 spin_lock_irqsave(&ctlr->queue_lock, flags);
1755 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1757 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1761 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1764 * spi_finalize_current_message() - the current message is complete
1765 * @ctlr: the controller to return the message to
1767 * Called by the driver to notify the core that the message in the front of the
1768 * queue is complete and can be removed from the queue.
1770 void spi_finalize_current_message(struct spi_controller *ctlr)
1772 struct spi_transfer *xfer;
1773 struct spi_message *mesg;
1774 unsigned long flags;
1777 spin_lock_irqsave(&ctlr->queue_lock, flags);
1778 mesg = ctlr->cur_msg;
1779 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1781 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1782 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
1783 ptp_read_system_postts(xfer->ptp_sts);
1784 xfer->ptp_sts_word_post = xfer->len;
1788 if (unlikely(ctlr->ptp_sts_supported))
1789 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
1790 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
1792 spi_unmap_msg(ctlr, mesg);
1794 /* In the prepare_messages callback the spi bus has the opportunity to
1795 * split a transfer to smaller chunks.
1796 * Release splited transfers here since spi_map_msg is done on the
1797 * splited transfers.
1799 spi_res_release(ctlr, mesg);
1801 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1802 ret = ctlr->unprepare_message(ctlr, mesg);
1804 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1809 spin_lock_irqsave(&ctlr->queue_lock, flags);
1810 ctlr->cur_msg = NULL;
1811 ctlr->cur_msg_prepared = false;
1812 ctlr->fallback = false;
1813 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1814 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1816 trace_spi_message_done(mesg);
1820 mesg->complete(mesg->context);
1822 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1824 static int spi_start_queue(struct spi_controller *ctlr)
1826 unsigned long flags;
1828 spin_lock_irqsave(&ctlr->queue_lock, flags);
1830 if (ctlr->running || ctlr->busy) {
1831 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1835 ctlr->running = true;
1836 ctlr->cur_msg = NULL;
1837 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1839 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1844 static int spi_stop_queue(struct spi_controller *ctlr)
1846 unsigned long flags;
1847 unsigned limit = 500;
1850 spin_lock_irqsave(&ctlr->queue_lock, flags);
1853 * This is a bit lame, but is optimized for the common execution path.
1854 * A wait_queue on the ctlr->busy could be used, but then the common
1855 * execution path (pump_messages) would be required to call wake_up or
1856 * friends on every SPI message. Do this instead.
1858 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1859 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1860 usleep_range(10000, 11000);
1861 spin_lock_irqsave(&ctlr->queue_lock, flags);
1864 if (!list_empty(&ctlr->queue) || ctlr->busy)
1867 ctlr->running = false;
1869 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1872 dev_warn(&ctlr->dev, "could not stop message queue\n");
1878 static int spi_destroy_queue(struct spi_controller *ctlr)
1882 ret = spi_stop_queue(ctlr);
1885 * kthread_flush_worker will block until all work is done.
1886 * If the reason that stop_queue timed out is that the work will never
1887 * finish, then it does no good to call flush/stop thread, so
1891 dev_err(&ctlr->dev, "problem destroying queue\n");
1895 kthread_destroy_worker(ctlr->kworker);
1900 static int __spi_queued_transfer(struct spi_device *spi,
1901 struct spi_message *msg,
1904 struct spi_controller *ctlr = spi->controller;
1905 unsigned long flags;
1907 spin_lock_irqsave(&ctlr->queue_lock, flags);
1909 if (!ctlr->running) {
1910 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1913 msg->actual_length = 0;
1914 msg->status = -EINPROGRESS;
1916 list_add_tail(&msg->queue, &ctlr->queue);
1917 if (!ctlr->busy && need_pump)
1918 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1920 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1925 * spi_queued_transfer - transfer function for queued transfers
1926 * @spi: spi device which is requesting transfer
1927 * @msg: spi message which is to handled is queued to driver queue
1929 * Return: zero on success, else a negative error code.
1931 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1933 return __spi_queued_transfer(spi, msg, true);
1936 static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1940 ctlr->transfer = spi_queued_transfer;
1941 if (!ctlr->transfer_one_message)
1942 ctlr->transfer_one_message = spi_transfer_one_message;
1944 /* Initialize and start queue */
1945 ret = spi_init_queue(ctlr);
1947 dev_err(&ctlr->dev, "problem initializing queue\n");
1948 goto err_init_queue;
1950 ctlr->queued = true;
1951 ret = spi_start_queue(ctlr);
1953 dev_err(&ctlr->dev, "problem starting queue\n");
1954 goto err_start_queue;
1960 spi_destroy_queue(ctlr);
1966 * spi_flush_queue - Send all pending messages in the queue from the callers'
1968 * @ctlr: controller to process queue for
1970 * This should be used when one wants to ensure all pending messages have been
1971 * sent before doing something. Is used by the spi-mem code to make sure SPI
1972 * memory operations do not preempt regular SPI transfers that have been queued
1973 * before the spi-mem operation.
1975 void spi_flush_queue(struct spi_controller *ctlr)
1977 if (ctlr->transfer == spi_queued_transfer)
1978 __spi_pump_messages(ctlr, false);
1981 /*-------------------------------------------------------------------------*/
1983 #if defined(CONFIG_OF)
1984 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1985 struct device_node *nc)
1990 /* Mode (clock phase/polarity/etc.) */
1991 if (of_property_read_bool(nc, "spi-cpha"))
1992 spi->mode |= SPI_CPHA;
1993 if (of_property_read_bool(nc, "spi-cpol"))
1994 spi->mode |= SPI_CPOL;
1995 if (of_property_read_bool(nc, "spi-3wire"))
1996 spi->mode |= SPI_3WIRE;
1997 if (of_property_read_bool(nc, "spi-lsb-first"))
1998 spi->mode |= SPI_LSB_FIRST;
1999 if (of_property_read_bool(nc, "spi-cs-high"))
2000 spi->mode |= SPI_CS_HIGH;
2002 /* Device DUAL/QUAD mode */
2003 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
2006 spi->mode |= SPI_NO_TX;
2011 spi->mode |= SPI_TX_DUAL;
2014 spi->mode |= SPI_TX_QUAD;
2017 spi->mode |= SPI_TX_OCTAL;
2020 dev_warn(&ctlr->dev,
2021 "spi-tx-bus-width %d not supported\n",
2027 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
2030 spi->mode |= SPI_NO_RX;
2035 spi->mode |= SPI_RX_DUAL;
2038 spi->mode |= SPI_RX_QUAD;
2041 spi->mode |= SPI_RX_OCTAL;
2044 dev_warn(&ctlr->dev,
2045 "spi-rx-bus-width %d not supported\n",
2051 if (spi_controller_is_slave(ctlr)) {
2052 if (!of_node_name_eq(nc, "slave")) {
2053 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
2060 /* Device address */
2061 rc = of_property_read_u32(nc, "reg", &value);
2063 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
2067 spi->chip_select = value;
2070 if (!of_property_read_u32(nc, "spi-max-frequency", &value))
2071 spi->max_speed_hz = value;
2076 static struct spi_device *
2077 of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
2079 struct spi_device *spi;
2082 /* Alloc an spi_device */
2083 spi = spi_alloc_device(ctlr);
2085 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
2090 /* Select device driver */
2091 rc = of_modalias_node(nc, spi->modalias,
2092 sizeof(spi->modalias));
2094 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
2098 rc = of_spi_parse_dt(ctlr, spi, nc);
2102 /* Store a pointer to the node in the device structure */
2104 spi->dev.of_node = nc;
2105 spi->dev.fwnode = of_fwnode_handle(nc);
2107 /* Register the new device */
2108 rc = spi_add_device(spi);
2110 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
2111 goto err_of_node_put;
2124 * of_register_spi_devices() - Register child devices onto the SPI bus
2125 * @ctlr: Pointer to spi_controller device
2127 * Registers an spi_device for each child node of controller node which
2128 * represents a valid SPI slave.
2130 static void of_register_spi_devices(struct spi_controller *ctlr)
2132 struct spi_device *spi;
2133 struct device_node *nc;
2135 if (!ctlr->dev.of_node)
2138 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2139 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2141 spi = of_register_spi_device(ctlr, nc);
2143 dev_warn(&ctlr->dev,
2144 "Failed to create SPI device for %pOF\n", nc);
2145 of_node_clear_flag(nc, OF_POPULATED);
2150 static void of_register_spi_devices(struct spi_controller *ctlr) { }
2154 * spi_new_ancillary_device() - Register ancillary SPI device
2155 * @spi: Pointer to the main SPI device registering the ancillary device
2156 * @chip_select: Chip Select of the ancillary device
2158 * Register an ancillary SPI device; for example some chips have a chip-select
2159 * for normal device usage and another one for setup/firmware upload.
2161 * This may only be called from main SPI device's probe routine.
2163 * Return: 0 on success; negative errno on failure
2165 struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
2168 struct spi_device *ancillary;
2171 /* Alloc an spi_device */
2172 ancillary = spi_alloc_device(spi->controller);
2178 strlcpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));
2180 /* Use provided chip-select for ancillary device */
2181 ancillary->chip_select = chip_select;
2183 /* Take over SPI mode/speed from SPI main device */
2184 ancillary->max_speed_hz = spi->max_speed_hz;
2185 ancillary->mode = spi->mode;
2187 /* Register the new device */
2188 rc = spi_add_device_locked(ancillary);
2190 dev_err(&spi->dev, "failed to register ancillary device\n");
2197 spi_dev_put(ancillary);
2200 EXPORT_SYMBOL_GPL(spi_new_ancillary_device);
2203 struct acpi_spi_lookup {
2204 struct spi_controller *ctlr;
2212 static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2213 struct acpi_spi_lookup *lookup)
2215 const union acpi_object *obj;
2217 if (!x86_apple_machine)
2220 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2221 && obj->buffer.length >= 4)
2222 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2224 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2225 && obj->buffer.length == 8)
2226 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2228 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2229 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2230 lookup->mode |= SPI_LSB_FIRST;
2232 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2233 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2234 lookup->mode |= SPI_CPOL;
2236 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2237 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2238 lookup->mode |= SPI_CPHA;
2241 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2243 struct acpi_spi_lookup *lookup = data;
2244 struct spi_controller *ctlr = lookup->ctlr;
2246 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2247 struct acpi_resource_spi_serialbus *sb;
2248 acpi_handle parent_handle;
2251 sb = &ares->data.spi_serial_bus;
2252 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2254 status = acpi_get_handle(NULL,
2255 sb->resource_source.string_ptr,
2258 if (ACPI_FAILURE(status) ||
2259 ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
2263 * ACPI DeviceSelection numbering is handled by the
2264 * host controller driver in Windows and can vary
2265 * from driver to driver. In Linux we always expect
2266 * 0 .. max - 1 so we need to ask the driver to
2267 * translate between the two schemes.
2269 if (ctlr->fw_translate_cs) {
2270 int cs = ctlr->fw_translate_cs(ctlr,
2271 sb->device_selection);
2274 lookup->chip_select = cs;
2276 lookup->chip_select = sb->device_selection;
2279 lookup->max_speed_hz = sb->connection_speed;
2280 lookup->bits_per_word = sb->data_bit_length;
2282 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2283 lookup->mode |= SPI_CPHA;
2284 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2285 lookup->mode |= SPI_CPOL;
2286 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2287 lookup->mode |= SPI_CS_HIGH;
2289 } else if (lookup->irq < 0) {
2292 if (acpi_dev_resource_interrupt(ares, 0, &r))
2293 lookup->irq = r.start;
2296 /* Always tell the ACPI core to skip this resource */
2300 static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2301 struct acpi_device *adev)
2303 acpi_handle parent_handle = NULL;
2304 struct list_head resource_list;
2305 struct acpi_spi_lookup lookup = {};
2306 struct spi_device *spi;
2309 if (acpi_bus_get_status(adev) || !adev->status.present ||
2310 acpi_device_enumerated(adev))
2316 INIT_LIST_HEAD(&resource_list);
2317 ret = acpi_dev_get_resources(adev, &resource_list,
2318 acpi_spi_add_resource, &lookup);
2319 acpi_dev_free_resource_list(&resource_list);
2322 /* found SPI in _CRS but it points to another controller */
2325 if (!lookup.max_speed_hz &&
2326 ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
2327 ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {
2328 /* Apple does not use _CRS but nested devices for SPI slaves */
2329 acpi_spi_parse_apple_properties(adev, &lookup);
2332 if (!lookup.max_speed_hz)
2335 spi = spi_alloc_device(ctlr);
2337 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
2338 dev_name(&adev->dev));
2339 return AE_NO_MEMORY;
2343 ACPI_COMPANION_SET(&spi->dev, adev);
2344 spi->max_speed_hz = lookup.max_speed_hz;
2345 spi->mode |= lookup.mode;
2346 spi->irq = lookup.irq;
2347 spi->bits_per_word = lookup.bits_per_word;
2348 spi->chip_select = lookup.chip_select;
2350 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2351 sizeof(spi->modalias));
2354 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
2356 acpi_device_set_enumerated(adev);
2358 adev->power.flags.ignore_parent = true;
2359 if (spi_add_device(spi)) {
2360 adev->power.flags.ignore_parent = false;
2361 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2362 dev_name(&adev->dev));
2369 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2370 void *data, void **return_value)
2372 struct spi_controller *ctlr = data;
2373 struct acpi_device *adev;
2375 if (acpi_bus_get_device(handle, &adev))
2378 return acpi_register_spi_device(ctlr, adev);
2381 #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2383 static void acpi_register_spi_devices(struct spi_controller *ctlr)
2388 handle = ACPI_HANDLE(ctlr->dev.parent);
2392 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2393 SPI_ACPI_ENUMERATE_MAX_DEPTH,
2394 acpi_spi_add_device, NULL, ctlr, NULL);
2395 if (ACPI_FAILURE(status))
2396 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2399 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2400 #endif /* CONFIG_ACPI */
2402 static void spi_controller_release(struct device *dev)
2404 struct spi_controller *ctlr;
2406 ctlr = container_of(dev, struct spi_controller, dev);
2410 static struct class spi_master_class = {
2411 .name = "spi_master",
2412 .owner = THIS_MODULE,
2413 .dev_release = spi_controller_release,
2414 .dev_groups = spi_master_groups,
2417 #ifdef CONFIG_SPI_SLAVE
2419 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2421 * @spi: device used for the current transfer
2423 int spi_slave_abort(struct spi_device *spi)
2425 struct spi_controller *ctlr = spi->controller;
2427 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
2428 return ctlr->slave_abort(ctlr);
2432 EXPORT_SYMBOL_GPL(spi_slave_abort);
2434 static int match_true(struct device *dev, void *data)
2439 static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2442 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2444 struct device *child;
2446 child = device_find_child(&ctlr->dev, NULL, match_true);
2447 return sprintf(buf, "%s\n",
2448 child ? to_spi_device(child)->modalias : NULL);
2451 static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
2452 const char *buf, size_t count)
2454 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2456 struct spi_device *spi;
2457 struct device *child;
2461 rc = sscanf(buf, "%31s", name);
2462 if (rc != 1 || !name[0])
2465 child = device_find_child(&ctlr->dev, NULL, match_true);
2467 /* Remove registered slave */
2468 device_unregister(child);
2472 if (strcmp(name, "(null)")) {
2473 /* Register new slave */
2474 spi = spi_alloc_device(ctlr);
2478 strlcpy(spi->modalias, name, sizeof(spi->modalias));
2480 rc = spi_add_device(spi);
2490 static DEVICE_ATTR_RW(slave);
2492 static struct attribute *spi_slave_attrs[] = {
2493 &dev_attr_slave.attr,
2497 static const struct attribute_group spi_slave_group = {
2498 .attrs = spi_slave_attrs,
2501 static const struct attribute_group *spi_slave_groups[] = {
2502 &spi_controller_statistics_group,
2507 static struct class spi_slave_class = {
2508 .name = "spi_slave",
2509 .owner = THIS_MODULE,
2510 .dev_release = spi_controller_release,
2511 .dev_groups = spi_slave_groups,
2514 extern struct class spi_slave_class; /* dummy */
2518 * __spi_alloc_controller - allocate an SPI master or slave controller
2519 * @dev: the controller, possibly using the platform_bus
2520 * @size: how much zeroed driver-private data to allocate; the pointer to this
2521 * memory is in the driver_data field of the returned device, accessible
2522 * with spi_controller_get_devdata(); the memory is cacheline aligned;
2523 * drivers granting DMA access to portions of their private data need to
2524 * round up @size using ALIGN(size, dma_get_cache_alignment()).
2525 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2526 * slave (true) controller
2527 * Context: can sleep
2529 * This call is used only by SPI controller drivers, which are the
2530 * only ones directly touching chip registers. It's how they allocate
2531 * an spi_controller structure, prior to calling spi_register_controller().
2533 * This must be called from context that can sleep.
2535 * The caller is responsible for assigning the bus number and initializing the
2536 * controller's methods before calling spi_register_controller(); and (after
2537 * errors adding the device) calling spi_controller_put() to prevent a memory
2540 * Return: the SPI controller structure on success, else NULL.
2542 struct spi_controller *__spi_alloc_controller(struct device *dev,
2543 unsigned int size, bool slave)
2545 struct spi_controller *ctlr;
2546 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
2551 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
2555 device_initialize(&ctlr->dev);
2557 ctlr->num_chipselect = 1;
2558 ctlr->slave = slave;
2559 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2560 ctlr->dev.class = &spi_slave_class;
2562 ctlr->dev.class = &spi_master_class;
2563 ctlr->dev.parent = dev;
2564 pm_suspend_ignore_children(&ctlr->dev, true);
2565 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
2569 EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2571 static void devm_spi_release_controller(struct device *dev, void *ctlr)
2573 spi_controller_put(*(struct spi_controller **)ctlr);
2577 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
2578 * @dev: physical device of SPI controller
2579 * @size: how much zeroed driver-private data to allocate
2580 * @slave: whether to allocate an SPI master (false) or SPI slave (true)
2581 * Context: can sleep
2583 * Allocate an SPI controller and automatically release a reference on it
2584 * when @dev is unbound from its driver. Drivers are thus relieved from
2585 * having to call spi_controller_put().
2587 * The arguments to this function are identical to __spi_alloc_controller().
2589 * Return: the SPI controller structure on success, else NULL.
2591 struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
2595 struct spi_controller **ptr, *ctlr;
2597 ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),
2602 ctlr = __spi_alloc_controller(dev, size, slave);
2604 ctlr->devm_allocated = true;
2606 devres_add(dev, ptr);
2613 EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);
2616 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2619 struct device_node *np = ctlr->dev.of_node;
2624 nb = of_gpio_named_count(np, "cs-gpios");
2625 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2627 /* Return error only for an incorrectly formed cs-gpios property */
2628 if (nb == 0 || nb == -ENOENT)
2633 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2635 ctlr->cs_gpios = cs;
2637 if (!ctlr->cs_gpios)
2640 for (i = 0; i < ctlr->num_chipselect; i++)
2643 for (i = 0; i < nb; i++)
2644 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2649 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2656 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2657 * @ctlr: The SPI master to grab GPIO descriptors for
2659 static int spi_get_gpio_descs(struct spi_controller *ctlr)
2662 struct gpio_desc **cs;
2663 struct device *dev = &ctlr->dev;
2664 unsigned long native_cs_mask = 0;
2665 unsigned int num_cs_gpios = 0;
2667 nb = gpiod_count(dev, "cs");
2669 /* No GPIOs at all is fine, else return the error */
2675 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2677 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
2681 ctlr->cs_gpiods = cs;
2683 for (i = 0; i < nb; i++) {
2685 * Most chipselects are active low, the inverted
2686 * semantics are handled by special quirks in gpiolib,
2687 * so initializing them GPIOD_OUT_LOW here means
2688 * "unasserted", in most cases this will drive the physical
2691 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
2694 return PTR_ERR(cs[i]);
2698 * If we find a CS GPIO, name it after the device and
2703 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
2707 gpiod_set_consumer_name(cs[i], gpioname);
2712 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
2713 dev_err(dev, "Invalid native chip select %d\n", i);
2716 native_cs_mask |= BIT(i);
2719 ctlr->unused_native_cs = ffs(~native_cs_mask) - 1;
2721 if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios &&
2722 ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {
2723 dev_err(dev, "No unused native chip select available\n");
2730 static int spi_controller_check_ops(struct spi_controller *ctlr)
2733 * The controller may implement only the high-level SPI-memory like
2734 * operations if it does not support regular SPI transfers, and this is
2736 * If ->mem_ops is NULL, we request that at least one of the
2737 * ->transfer_xxx() method be implemented.
2739 if (ctlr->mem_ops) {
2740 if (!ctlr->mem_ops->exec_op)
2742 } else if (!ctlr->transfer && !ctlr->transfer_one &&
2743 !ctlr->transfer_one_message) {
2751 * spi_register_controller - register SPI master or slave controller
2752 * @ctlr: initialized master, originally from spi_alloc_master() or
2754 * Context: can sleep
2756 * SPI controllers connect to their drivers using some non-SPI bus,
2757 * such as the platform bus. The final stage of probe() in that code
2758 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2760 * SPI controllers use board specific (often SOC specific) bus numbers,
2761 * and board-specific addressing for SPI devices combines those numbers
2762 * with chip select numbers. Since SPI does not directly support dynamic
2763 * device identification, boards need configuration tables telling which
2764 * chip is at which address.
2766 * This must be called from context that can sleep. It returns zero on
2767 * success, else a negative error code (dropping the controller's refcount).
2768 * After a successful return, the caller is responsible for calling
2769 * spi_unregister_controller().
2771 * Return: zero on success, else a negative error code.
2773 int spi_register_controller(struct spi_controller *ctlr)
2775 struct device *dev = ctlr->dev.parent;
2776 struct boardinfo *bi;
2778 int id, first_dynamic;
2784 * Make sure all necessary hooks are implemented before registering
2785 * the SPI controller.
2787 status = spi_controller_check_ops(ctlr);
2791 if (ctlr->bus_num >= 0) {
2792 /* devices with a fixed bus num must check-in with the num */
2793 mutex_lock(&board_lock);
2794 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2795 ctlr->bus_num + 1, GFP_KERNEL);
2796 mutex_unlock(&board_lock);
2797 if (WARN(id < 0, "couldn't get idr"))
2798 return id == -ENOSPC ? -EBUSY : id;
2800 } else if (ctlr->dev.of_node) {
2801 /* allocate dynamic bus number using Linux idr */
2802 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2805 mutex_lock(&board_lock);
2806 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2807 ctlr->bus_num + 1, GFP_KERNEL);
2808 mutex_unlock(&board_lock);
2809 if (WARN(id < 0, "couldn't get idr"))
2810 return id == -ENOSPC ? -EBUSY : id;
2813 if (ctlr->bus_num < 0) {
2814 first_dynamic = of_alias_get_highest_id("spi");
2815 if (first_dynamic < 0)
2820 mutex_lock(&board_lock);
2821 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2823 mutex_unlock(&board_lock);
2824 if (WARN(id < 0, "couldn't get idr"))
2828 INIT_LIST_HEAD(&ctlr->queue);
2829 spin_lock_init(&ctlr->queue_lock);
2830 spin_lock_init(&ctlr->bus_lock_spinlock);
2831 mutex_init(&ctlr->bus_lock_mutex);
2832 mutex_init(&ctlr->io_mutex);
2833 ctlr->bus_lock_flag = 0;
2834 init_completion(&ctlr->xfer_completion);
2835 if (!ctlr->max_dma_len)
2836 ctlr->max_dma_len = INT_MAX;
2838 /* register the device, then userspace will see it.
2839 * registration fails if the bus ID is in use.
2841 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2843 if (!spi_controller_is_slave(ctlr)) {
2844 if (ctlr->use_gpio_descriptors) {
2845 status = spi_get_gpio_descs(ctlr);
2849 * A controller using GPIO descriptors always
2850 * supports SPI_CS_HIGH if need be.
2852 ctlr->mode_bits |= SPI_CS_HIGH;
2854 /* Legacy code path for GPIOs from DT */
2855 status = of_spi_get_gpio_numbers(ctlr);
2862 * Even if it's just one always-selected device, there must
2863 * be at least one chipselect.
2865 if (!ctlr->num_chipselect) {
2870 status = device_add(&ctlr->dev);
2873 dev_dbg(dev, "registered %s %s\n",
2874 spi_controller_is_slave(ctlr) ? "slave" : "master",
2875 dev_name(&ctlr->dev));
2878 * If we're using a queued driver, start the queue. Note that we don't
2879 * need the queueing logic if the driver is only supporting high-level
2880 * memory operations.
2882 if (ctlr->transfer) {
2883 dev_info(dev, "controller is unqueued, this is deprecated\n");
2884 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2885 status = spi_controller_initialize_queue(ctlr);
2887 device_del(&ctlr->dev);
2891 /* add statistics */
2892 spin_lock_init(&ctlr->statistics.lock);
2894 mutex_lock(&board_lock);
2895 list_add_tail(&ctlr->list, &spi_controller_list);
2896 list_for_each_entry(bi, &board_list, list)
2897 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2898 mutex_unlock(&board_lock);
2900 /* Register devices from the device tree and ACPI */
2901 of_register_spi_devices(ctlr);
2902 acpi_register_spi_devices(ctlr);
2906 mutex_lock(&board_lock);
2907 idr_remove(&spi_master_idr, ctlr->bus_num);
2908 mutex_unlock(&board_lock);
2911 EXPORT_SYMBOL_GPL(spi_register_controller);
2913 static void devm_spi_unregister(void *ctlr)
2915 spi_unregister_controller(ctlr);
2919 * devm_spi_register_controller - register managed SPI master or slave
2921 * @dev: device managing SPI controller
2922 * @ctlr: initialized controller, originally from spi_alloc_master() or
2924 * Context: can sleep
2926 * Register a SPI device as with spi_register_controller() which will
2927 * automatically be unregistered and freed.
2929 * Return: zero on success, else a negative error code.
2931 int devm_spi_register_controller(struct device *dev,
2932 struct spi_controller *ctlr)
2936 ret = spi_register_controller(ctlr);
2940 return devm_add_action_or_reset(dev, devm_spi_unregister, ctlr);
2942 EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2944 static int __unregister(struct device *dev, void *null)
2946 spi_unregister_device(to_spi_device(dev));
2951 * spi_unregister_controller - unregister SPI master or slave controller
2952 * @ctlr: the controller being unregistered
2953 * Context: can sleep
2955 * This call is used only by SPI controller drivers, which are the
2956 * only ones directly touching chip registers.
2958 * This must be called from context that can sleep.
2960 * Note that this function also drops a reference to the controller.
2962 void spi_unregister_controller(struct spi_controller *ctlr)
2964 struct spi_controller *found;
2965 int id = ctlr->bus_num;
2967 /* Prevent addition of new devices, unregister existing ones */
2968 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2969 mutex_lock(&spi_add_lock);
2971 device_for_each_child(&ctlr->dev, NULL, __unregister);
2973 /* First make sure that this controller was ever added */
2974 mutex_lock(&board_lock);
2975 found = idr_find(&spi_master_idr, id);
2976 mutex_unlock(&board_lock);
2978 if (spi_destroy_queue(ctlr))
2979 dev_err(&ctlr->dev, "queue remove failed\n");
2981 mutex_lock(&board_lock);
2982 list_del(&ctlr->list);
2983 mutex_unlock(&board_lock);
2985 device_del(&ctlr->dev);
2987 /* Release the last reference on the controller if its driver
2988 * has not yet been converted to devm_spi_alloc_master/slave().
2990 if (!ctlr->devm_allocated)
2991 put_device(&ctlr->dev);
2994 mutex_lock(&board_lock);
2996 idr_remove(&spi_master_idr, id);
2997 mutex_unlock(&board_lock);
2999 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
3000 mutex_unlock(&spi_add_lock);
3002 EXPORT_SYMBOL_GPL(spi_unregister_controller);
3004 int spi_controller_suspend(struct spi_controller *ctlr)
3008 /* Basically no-ops for non-queued controllers */
3012 ret = spi_stop_queue(ctlr);
3014 dev_err(&ctlr->dev, "queue stop failed\n");
3018 EXPORT_SYMBOL_GPL(spi_controller_suspend);
3020 int spi_controller_resume(struct spi_controller *ctlr)
3027 ret = spi_start_queue(ctlr);
3029 dev_err(&ctlr->dev, "queue restart failed\n");
3033 EXPORT_SYMBOL_GPL(spi_controller_resume);
3035 static int __spi_controller_match(struct device *dev, const void *data)
3037 struct spi_controller *ctlr;
3038 const u16 *bus_num = data;
3040 ctlr = container_of(dev, struct spi_controller, dev);
3041 return ctlr->bus_num == *bus_num;
3045 * spi_busnum_to_master - look up master associated with bus_num
3046 * @bus_num: the master's bus number
3047 * Context: can sleep
3049 * This call may be used with devices that are registered after
3050 * arch init time. It returns a refcounted pointer to the relevant
3051 * spi_controller (which the caller must release), or NULL if there is
3052 * no such master registered.
3054 * Return: the SPI master structure on success, else NULL.
3056 struct spi_controller *spi_busnum_to_master(u16 bus_num)
3059 struct spi_controller *ctlr = NULL;
3061 dev = class_find_device(&spi_master_class, NULL, &bus_num,
3062 __spi_controller_match);
3064 ctlr = container_of(dev, struct spi_controller, dev);
3065 /* reference got in class_find_device */
3068 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
3070 /*-------------------------------------------------------------------------*/
3072 /* Core methods for SPI resource management */
3075 * spi_res_alloc - allocate a spi resource that is life-cycle managed
3076 * during the processing of a spi_message while using
3078 * @spi: the spi device for which we allocate memory
3079 * @release: the release code to execute for this resource
3080 * @size: size to alloc and return
3081 * @gfp: GFP allocation flags
3083 * Return: the pointer to the allocated data
3085 * This may get enhanced in the future to allocate from a memory pool
3086 * of the @spi_device or @spi_controller to avoid repeated allocations.
3088 void *spi_res_alloc(struct spi_device *spi,
3089 spi_res_release_t release,
3090 size_t size, gfp_t gfp)
3092 struct spi_res *sres;
3094 sres = kzalloc(sizeof(*sres) + size, gfp);
3098 INIT_LIST_HEAD(&sres->entry);
3099 sres->release = release;
3103 EXPORT_SYMBOL_GPL(spi_res_alloc);
3106 * spi_res_free - free an spi resource
3107 * @res: pointer to the custom data of a resource
3110 void spi_res_free(void *res)
3112 struct spi_res *sres = container_of(res, struct spi_res, data);
3117 WARN_ON(!list_empty(&sres->entry));
3120 EXPORT_SYMBOL_GPL(spi_res_free);
3123 * spi_res_add - add a spi_res to the spi_message
3124 * @message: the spi message
3125 * @res: the spi_resource
3127 void spi_res_add(struct spi_message *message, void *res)
3129 struct spi_res *sres = container_of(res, struct spi_res, data);
3131 WARN_ON(!list_empty(&sres->entry));
3132 list_add_tail(&sres->entry, &message->resources);
3134 EXPORT_SYMBOL_GPL(spi_res_add);
3137 * spi_res_release - release all spi resources for this message
3138 * @ctlr: the @spi_controller
3139 * @message: the @spi_message
3141 void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
3143 struct spi_res *res, *tmp;
3145 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
3147 res->release(ctlr, message, res->data);
3149 list_del(&res->entry);
3154 EXPORT_SYMBOL_GPL(spi_res_release);
3156 /*-------------------------------------------------------------------------*/
3158 /* Core methods for spi_message alterations */
3160 static void __spi_replace_transfers_release(struct spi_controller *ctlr,
3161 struct spi_message *msg,
3164 struct spi_replaced_transfers *rxfer = res;
3167 /* call extra callback if requested */
3169 rxfer->release(ctlr, msg, res);
3171 /* insert replaced transfers back into the message */
3172 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
3174 /* remove the formerly inserted entries */
3175 for (i = 0; i < rxfer->inserted; i++)
3176 list_del(&rxfer->inserted_transfers[i].transfer_list);
3180 * spi_replace_transfers - replace transfers with several transfers
3181 * and register change with spi_message.resources
3182 * @msg: the spi_message we work upon
3183 * @xfer_first: the first spi_transfer we want to replace
3184 * @remove: number of transfers to remove
3185 * @insert: the number of transfers we want to insert instead
3186 * @release: extra release code necessary in some circumstances
3187 * @extradatasize: extra data to allocate (with alignment guarantees
3188 * of struct @spi_transfer)
3191 * Returns: pointer to @spi_replaced_transfers,
3192 * PTR_ERR(...) in case of errors.
3194 struct spi_replaced_transfers *spi_replace_transfers(
3195 struct spi_message *msg,
3196 struct spi_transfer *xfer_first,
3199 spi_replaced_release_t release,
3200 size_t extradatasize,
3203 struct spi_replaced_transfers *rxfer;
3204 struct spi_transfer *xfer;
3207 /* allocate the structure using spi_res */
3208 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
3209 struct_size(rxfer, inserted_transfers, insert)
3213 return ERR_PTR(-ENOMEM);
3215 /* the release code to invoke before running the generic release */
3216 rxfer->release = release;
3218 /* assign extradata */
3221 &rxfer->inserted_transfers[insert];
3223 /* init the replaced_transfers list */
3224 INIT_LIST_HEAD(&rxfer->replaced_transfers);
3226 /* assign the list_entry after which we should reinsert
3227 * the @replaced_transfers - it may be spi_message.messages!
3229 rxfer->replaced_after = xfer_first->transfer_list.prev;
3231 /* remove the requested number of transfers */
3232 for (i = 0; i < remove; i++) {
3233 /* if the entry after replaced_after it is msg->transfers
3234 * then we have been requested to remove more transfers
3235 * than are in the list
3237 if (rxfer->replaced_after->next == &msg->transfers) {
3238 dev_err(&msg->spi->dev,
3239 "requested to remove more spi_transfers than are available\n");
3240 /* insert replaced transfers back into the message */
3241 list_splice(&rxfer->replaced_transfers,
3242 rxfer->replaced_after);
3244 /* free the spi_replace_transfer structure */
3245 spi_res_free(rxfer);
3247 /* and return with an error */
3248 return ERR_PTR(-EINVAL);
3251 /* remove the entry after replaced_after from list of
3252 * transfers and add it to list of replaced_transfers
3254 list_move_tail(rxfer->replaced_after->next,
3255 &rxfer->replaced_transfers);
3258 /* create copy of the given xfer with identical settings
3259 * based on the first transfer to get removed
3261 for (i = 0; i < insert; i++) {
3262 /* we need to run in reverse order */
3263 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3265 /* copy all spi_transfer data */
3266 memcpy(xfer, xfer_first, sizeof(*xfer));
3269 list_add(&xfer->transfer_list, rxfer->replaced_after);
3271 /* clear cs_change and delay for all but the last */
3273 xfer->cs_change = false;
3274 xfer->delay.value = 0;
3278 /* set up inserted */
3279 rxfer->inserted = insert;
3281 /* and register it with spi_res/spi_message */
3282 spi_res_add(msg, rxfer);
3286 EXPORT_SYMBOL_GPL(spi_replace_transfers);
3288 static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3289 struct spi_message *msg,
3290 struct spi_transfer **xferp,
3294 struct spi_transfer *xfer = *xferp, *xfers;
3295 struct spi_replaced_transfers *srt;
3299 /* calculate how many we have to replace */
3300 count = DIV_ROUND_UP(xfer->len, maxsize);
3302 /* create replacement */
3303 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
3305 return PTR_ERR(srt);
3306 xfers = srt->inserted_transfers;
3308 /* now handle each of those newly inserted spi_transfers
3309 * note that the replacements spi_transfers all are preset
3310 * to the same values as *xferp, so tx_buf, rx_buf and len
3311 * are all identical (as well as most others)
3312 * so we just have to fix up len and the pointers.
3314 * this also includes support for the depreciated
3315 * spi_message.is_dma_mapped interface
3318 /* the first transfer just needs the length modified, so we
3319 * run it outside the loop
3321 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3323 /* all the others need rx_buf/tx_buf also set */
3324 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3325 /* update rx_buf, tx_buf and dma */
3326 if (xfers[i].rx_buf)
3327 xfers[i].rx_buf += offset;
3328 if (xfers[i].rx_dma)
3329 xfers[i].rx_dma += offset;
3330 if (xfers[i].tx_buf)
3331 xfers[i].tx_buf += offset;
3332 if (xfers[i].tx_dma)
3333 xfers[i].tx_dma += offset;
3336 xfers[i].len = min(maxsize, xfers[i].len - offset);
3339 /* we set up xferp to the last entry we have inserted,
3340 * so that we skip those already split transfers
3342 *xferp = &xfers[count - 1];
3344 /* increment statistics counters */
3345 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3346 transfers_split_maxsize);
3347 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
3348 transfers_split_maxsize);
3354 * spi_split_transfers_maxsize - split spi transfers into multiple transfers
3355 * when an individual transfer exceeds a
3357 * @ctlr: the @spi_controller for this transfer
3358 * @msg: the @spi_message to transform
3359 * @maxsize: the maximum when to apply this
3360 * @gfp: GFP allocation flags
3362 * Return: status of transformation
3364 int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3365 struct spi_message *msg,
3369 struct spi_transfer *xfer;
3372 /* iterate over the transfer_list,
3373 * but note that xfer is advanced to the last transfer inserted
3374 * to avoid checking sizes again unnecessarily (also xfer does
3375 * potentiall belong to a different list by the time the
3376 * replacement has happened
3378 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3379 if (xfer->len > maxsize) {
3380 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3389 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3391 /*-------------------------------------------------------------------------*/
3393 /* Core methods for SPI controller protocol drivers. Some of the
3394 * other core methods are currently defined as inline functions.
3397 static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3400 if (ctlr->bits_per_word_mask) {
3401 /* Only 32 bits fit in the mask */
3402 if (bits_per_word > 32)
3404 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3412 * spi_setup - setup SPI mode and clock rate
3413 * @spi: the device whose settings are being modified
3414 * Context: can sleep, and no requests are queued to the device
3416 * SPI protocol drivers may need to update the transfer mode if the
3417 * device doesn't work with its default. They may likewise need
3418 * to update clock rates or word sizes from initial values. This function
3419 * changes those settings, and must be called from a context that can sleep.
3420 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3421 * effect the next time the device is selected and data is transferred to
3422 * or from it. When this function returns, the spi device is deselected.
3424 * Note that this call will fail if the protocol driver specifies an option
3425 * that the underlying controller or its driver does not support. For
3426 * example, not all hardware supports wire transfers using nine bit words,
3427 * LSB-first wire encoding, or active-high chipselects.
3429 * Return: zero on success, else a negative error code.
3431 int spi_setup(struct spi_device *spi)
3433 unsigned bad_bits, ugly_bits;
3437 * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
3438 * are set at the same time
3440 if ((hweight_long(spi->mode &
3441 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
3442 (hweight_long(spi->mode &
3443 (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
3445 "setup: can not select any two of dual, quad and no-rx/tx at the same time\n");
3448 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
3450 if ((spi->mode & SPI_3WIRE) && (spi->mode &
3451 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3452 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3454 /* help drivers fail *cleanly* when they need options
3455 * that aren't supported with their current controller
3456 * SPI_CS_WORD has a fallback software implementation,
3457 * so it is ignored here.
3459 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
3460 SPI_NO_TX | SPI_NO_RX);
3461 /* nothing prevents from working with active-high CS in case if it
3462 * is driven by GPIO.
3464 if (gpio_is_valid(spi->cs_gpio))
3465 bad_bits &= ~SPI_CS_HIGH;
3466 ugly_bits = bad_bits &
3467 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3468 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3471 "setup: ignoring unsupported mode bits %x\n",
3473 spi->mode &= ~ugly_bits;
3474 bad_bits &= ~ugly_bits;
3477 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3482 if (!spi->bits_per_word)
3483 spi->bits_per_word = 8;
3485 status = __spi_validate_bits_per_word(spi->controller,
3486 spi->bits_per_word);
3490 if (spi->controller->max_speed_hz &&
3491 (!spi->max_speed_hz ||
3492 spi->max_speed_hz > spi->controller->max_speed_hz))
3493 spi->max_speed_hz = spi->controller->max_speed_hz;
3495 mutex_lock(&spi->controller->io_mutex);
3497 if (spi->controller->setup) {
3498 status = spi->controller->setup(spi);
3500 mutex_unlock(&spi->controller->io_mutex);
3501 dev_err(&spi->controller->dev, "Failed to setup device: %d\n",
3507 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
3508 status = pm_runtime_get_sync(spi->controller->dev.parent);
3510 mutex_unlock(&spi->controller->io_mutex);
3511 pm_runtime_put_noidle(spi->controller->dev.parent);
3512 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3518 * We do not want to return positive value from pm_runtime_get,
3519 * there are many instances of devices calling spi_setup() and
3520 * checking for a non-zero return value instead of a negative
3525 spi_set_cs(spi, false, true);
3526 pm_runtime_mark_last_busy(spi->controller->dev.parent);
3527 pm_runtime_put_autosuspend(spi->controller->dev.parent);
3529 spi_set_cs(spi, false, true);
3532 mutex_unlock(&spi->controller->io_mutex);
3534 if (spi->rt && !spi->controller->rt) {
3535 spi->controller->rt = true;
3536 spi_set_thread_rt(spi->controller);
3539 trace_spi_setup(spi, status);
3541 dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3542 spi->mode & SPI_MODE_X_MASK,
3543 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
3544 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
3545 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
3546 (spi->mode & SPI_LOOP) ? "loopback, " : "",
3547 spi->bits_per_word, spi->max_speed_hz,
3552 EXPORT_SYMBOL_GPL(spi_setup);
3554 static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
3555 struct spi_device *spi)
3559 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
3563 delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
3567 if (delay1 < delay2)
3568 memcpy(&xfer->word_delay, &spi->word_delay,
3569 sizeof(xfer->word_delay));
3574 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
3576 struct spi_controller *ctlr = spi->controller;
3577 struct spi_transfer *xfer;
3580 if (list_empty(&message->transfers))
3583 /* If an SPI controller does not support toggling the CS line on each
3584 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3585 * for the CS line, we can emulate the CS-per-word hardware function by
3586 * splitting transfers into one-word transfers and ensuring that
3587 * cs_change is set for each transfer.
3589 if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
3591 gpio_is_valid(spi->cs_gpio))) {
3595 maxsize = (spi->bits_per_word + 7) / 8;
3597 /* spi_split_transfers_maxsize() requires message->spi */
3600 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
3605 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3606 /* don't change cs_change on the last entry in the list */
3607 if (list_is_last(&xfer->transfer_list, &message->transfers))
3609 xfer->cs_change = 1;
3613 /* Half-duplex links include original MicroWire, and ones with
3614 * only one data pin like SPI_3WIRE (switches direction) or where
3615 * either MOSI or MISO is missing. They can also be caused by
3616 * software limitations.
3618 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
3619 (spi->mode & SPI_3WIRE)) {
3620 unsigned flags = ctlr->flags;
3622 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3623 if (xfer->rx_buf && xfer->tx_buf)
3625 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
3627 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
3633 * Set transfer bits_per_word and max speed as spi device default if
3634 * it is not set for this transfer.
3635 * Set transfer tx_nbits and rx_nbits as single transfer default
3636 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3637 * Ensure transfer word_delay is at least as long as that required by
3640 message->frame_length = 0;
3641 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3642 xfer->effective_speed_hz = 0;
3643 message->frame_length += xfer->len;
3644 if (!xfer->bits_per_word)
3645 xfer->bits_per_word = spi->bits_per_word;
3647 if (!xfer->speed_hz)
3648 xfer->speed_hz = spi->max_speed_hz;
3650 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
3651 xfer->speed_hz = ctlr->max_speed_hz;
3653 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
3657 * SPI transfer length should be multiple of SPI word size
3658 * where SPI word size should be power-of-two multiple
3660 if (xfer->bits_per_word <= 8)
3662 else if (xfer->bits_per_word <= 16)
3667 /* No partial transfers accepted */
3668 if (xfer->len % w_size)
3671 if (xfer->speed_hz && ctlr->min_speed_hz &&
3672 xfer->speed_hz < ctlr->min_speed_hz)
3675 if (xfer->tx_buf && !xfer->tx_nbits)
3676 xfer->tx_nbits = SPI_NBITS_SINGLE;
3677 if (xfer->rx_buf && !xfer->rx_nbits)
3678 xfer->rx_nbits = SPI_NBITS_SINGLE;
3679 /* check transfer tx/rx_nbits:
3680 * 1. check the value matches one of single, dual and quad
3681 * 2. check tx/rx_nbits match the mode in spi_device
3684 if (spi->mode & SPI_NO_TX)
3686 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3687 xfer->tx_nbits != SPI_NBITS_DUAL &&
3688 xfer->tx_nbits != SPI_NBITS_QUAD)
3690 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3691 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3693 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3694 !(spi->mode & SPI_TX_QUAD))
3697 /* check transfer rx_nbits */
3699 if (spi->mode & SPI_NO_RX)
3701 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3702 xfer->rx_nbits != SPI_NBITS_DUAL &&
3703 xfer->rx_nbits != SPI_NBITS_QUAD)
3705 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3706 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3708 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3709 !(spi->mode & SPI_RX_QUAD))
3713 if (_spi_xfer_word_delay_update(xfer, spi))
3717 message->status = -EINPROGRESS;
3722 static int __spi_async(struct spi_device *spi, struct spi_message *message)
3724 struct spi_controller *ctlr = spi->controller;
3725 struct spi_transfer *xfer;
3728 * Some controllers do not support doing regular SPI transfers. Return
3729 * ENOTSUPP when this is the case.
3731 if (!ctlr->transfer)
3736 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
3737 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3739 trace_spi_message_submit(message);
3741 if (!ctlr->ptp_sts_supported) {
3742 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3743 xfer->ptp_sts_word_pre = 0;
3744 ptp_read_system_prets(xfer->ptp_sts);
3748 return ctlr->transfer(spi, message);
3752 * spi_async - asynchronous SPI transfer
3753 * @spi: device with which data will be exchanged
3754 * @message: describes the data transfers, including completion callback
3755 * Context: any (irqs may be blocked, etc)
3757 * This call may be used in_irq and other contexts which can't sleep,
3758 * as well as from task contexts which can sleep.
3760 * The completion callback is invoked in a context which can't sleep.
3761 * Before that invocation, the value of message->status is undefined.
3762 * When the callback is issued, message->status holds either zero (to
3763 * indicate complete success) or a negative error code. After that
3764 * callback returns, the driver which issued the transfer request may
3765 * deallocate the associated memory; it's no longer in use by any SPI
3766 * core or controller driver code.
3768 * Note that although all messages to a spi_device are handled in
3769 * FIFO order, messages may go to different devices in other orders.
3770 * Some device might be higher priority, or have various "hard" access
3771 * time requirements, for example.
3773 * On detection of any fault during the transfer, processing of
3774 * the entire message is aborted, and the device is deselected.
3775 * Until returning from the associated message completion callback,
3776 * no other spi_message queued to that device will be processed.
3777 * (This rule applies equally to all the synchronous transfer calls,
3778 * which are wrappers around this core asynchronous primitive.)
3780 * Return: zero on success, else a negative error code.
3782 int spi_async(struct spi_device *spi, struct spi_message *message)
3784 struct spi_controller *ctlr = spi->controller;
3786 unsigned long flags;
3788 ret = __spi_validate(spi, message);
3792 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3794 if (ctlr->bus_lock_flag)
3797 ret = __spi_async(spi, message);
3799 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3803 EXPORT_SYMBOL_GPL(spi_async);
3806 * spi_async_locked - version of spi_async with exclusive bus usage
3807 * @spi: device with which data will be exchanged
3808 * @message: describes the data transfers, including completion callback
3809 * Context: any (irqs may be blocked, etc)
3811 * This call may be used in_irq and other contexts which can't sleep,
3812 * as well as from task contexts which can sleep.
3814 * The completion callback is invoked in a context which can't sleep.
3815 * Before that invocation, the value of message->status is undefined.
3816 * When the callback is issued, message->status holds either zero (to
3817 * indicate complete success) or a negative error code. After that
3818 * callback returns, the driver which issued the transfer request may
3819 * deallocate the associated memory; it's no longer in use by any SPI
3820 * core or controller driver code.
3822 * Note that although all messages to a spi_device are handled in
3823 * FIFO order, messages may go to different devices in other orders.
3824 * Some device might be higher priority, or have various "hard" access
3825 * time requirements, for example.
3827 * On detection of any fault during the transfer, processing of
3828 * the entire message is aborted, and the device is deselected.
3829 * Until returning from the associated message completion callback,
3830 * no other spi_message queued to that device will be processed.
3831 * (This rule applies equally to all the synchronous transfer calls,
3832 * which are wrappers around this core asynchronous primitive.)
3834 * Return: zero on success, else a negative error code.
3836 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3838 struct spi_controller *ctlr = spi->controller;
3840 unsigned long flags;
3842 ret = __spi_validate(spi, message);
3846 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3848 ret = __spi_async(spi, message);
3850 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3855 EXPORT_SYMBOL_GPL(spi_async_locked);
3857 /*-------------------------------------------------------------------------*/
3859 /* Utility methods for SPI protocol drivers, layered on
3860 * top of the core. Some other utility methods are defined as
3864 static void spi_complete(void *arg)
3869 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3871 DECLARE_COMPLETION_ONSTACK(done);
3873 struct spi_controller *ctlr = spi->controller;
3874 unsigned long flags;
3876 status = __spi_validate(spi, message);
3880 message->complete = spi_complete;
3881 message->context = &done;
3884 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3885 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3887 /* If we're not using the legacy transfer method then we will
3888 * try to transfer in the calling context so special case.
3889 * This code would be less tricky if we could remove the
3890 * support for driver implemented message queues.
3892 if (ctlr->transfer == spi_queued_transfer) {
3893 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3895 trace_spi_message_submit(message);
3897 status = __spi_queued_transfer(spi, message, false);
3899 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3901 status = spi_async_locked(spi, message);
3905 /* Push out the messages in the calling context if we
3908 if (ctlr->transfer == spi_queued_transfer) {
3909 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3910 spi_sync_immediate);
3911 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3912 spi_sync_immediate);
3913 __spi_pump_messages(ctlr, false);
3916 wait_for_completion(&done);
3917 status = message->status;
3919 message->context = NULL;
3924 * spi_sync - blocking/synchronous SPI data transfers
3925 * @spi: device with which data will be exchanged
3926 * @message: describes the data transfers
3927 * Context: can sleep
3929 * This call may only be used from a context that may sleep. The sleep
3930 * is non-interruptible, and has no timeout. Low-overhead controller
3931 * drivers may DMA directly into and out of the message buffers.
3933 * Note that the SPI device's chip select is active during the message,
3934 * and then is normally disabled between messages. Drivers for some
3935 * frequently-used devices may want to minimize costs of selecting a chip,
3936 * by leaving it selected in anticipation that the next message will go
3937 * to the same chip. (That may increase power usage.)
3939 * Also, the caller is guaranteeing that the memory associated with the
3940 * message will not be freed before this call returns.
3942 * Return: zero on success, else a negative error code.
3944 int spi_sync(struct spi_device *spi, struct spi_message *message)
3948 mutex_lock(&spi->controller->bus_lock_mutex);
3949 ret = __spi_sync(spi, message);
3950 mutex_unlock(&spi->controller->bus_lock_mutex);
3954 EXPORT_SYMBOL_GPL(spi_sync);
3957 * spi_sync_locked - version of spi_sync with exclusive bus usage
3958 * @spi: device with which data will be exchanged
3959 * @message: describes the data transfers
3960 * Context: can sleep
3962 * This call may only be used from a context that may sleep. The sleep
3963 * is non-interruptible, and has no timeout. Low-overhead controller
3964 * drivers may DMA directly into and out of the message buffers.
3966 * This call should be used by drivers that require exclusive access to the
3967 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3968 * be released by a spi_bus_unlock call when the exclusive access is over.
3970 * Return: zero on success, else a negative error code.
3972 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3974 return __spi_sync(spi, message);
3976 EXPORT_SYMBOL_GPL(spi_sync_locked);
3979 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3980 * @ctlr: SPI bus master that should be locked for exclusive bus access
3981 * Context: can sleep
3983 * This call may only be used from a context that may sleep. The sleep
3984 * is non-interruptible, and has no timeout.
3986 * This call should be used by drivers that require exclusive access to the
3987 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3988 * exclusive access is over. Data transfer must be done by spi_sync_locked
3989 * and spi_async_locked calls when the SPI bus lock is held.
3991 * Return: always zero.
3993 int spi_bus_lock(struct spi_controller *ctlr)
3995 unsigned long flags;
3997 mutex_lock(&ctlr->bus_lock_mutex);
3999 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
4000 ctlr->bus_lock_flag = 1;
4001 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
4003 /* mutex remains locked until spi_bus_unlock is called */
4007 EXPORT_SYMBOL_GPL(spi_bus_lock);
4010 * spi_bus_unlock - release the lock for exclusive SPI bus usage
4011 * @ctlr: SPI bus master that was locked for exclusive bus access
4012 * Context: can sleep
4014 * This call may only be used from a context that may sleep. The sleep
4015 * is non-interruptible, and has no timeout.
4017 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
4020 * Return: always zero.
4022 int spi_bus_unlock(struct spi_controller *ctlr)
4024 ctlr->bus_lock_flag = 0;
4026 mutex_unlock(&ctlr->bus_lock_mutex);
4030 EXPORT_SYMBOL_GPL(spi_bus_unlock);
4032 /* portable code must never pass more than 32 bytes */
4033 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
4038 * spi_write_then_read - SPI synchronous write followed by read
4039 * @spi: device with which data will be exchanged
4040 * @txbuf: data to be written (need not be dma-safe)
4041 * @n_tx: size of txbuf, in bytes
4042 * @rxbuf: buffer into which data will be read (need not be dma-safe)
4043 * @n_rx: size of rxbuf, in bytes
4044 * Context: can sleep
4046 * This performs a half duplex MicroWire style transaction with the
4047 * device, sending txbuf and then reading rxbuf. The return value
4048 * is zero for success, else a negative errno status code.
4049 * This call may only be used from a context that may sleep.
4051 * Parameters to this routine are always copied using a small buffer.
4052 * Performance-sensitive or bulk transfer code should instead use
4053 * spi_{async,sync}() calls with dma-safe buffers.
4055 * Return: zero on success, else a negative error code.
4057 int spi_write_then_read(struct spi_device *spi,
4058 const void *txbuf, unsigned n_tx,
4059 void *rxbuf, unsigned n_rx)
4061 static DEFINE_MUTEX(lock);
4064 struct spi_message message;
4065 struct spi_transfer x[2];
4068 /* Use preallocated DMA-safe buffer if we can. We can't avoid
4069 * copying here, (as a pure convenience thing), but we can
4070 * keep heap costs out of the hot path unless someone else is
4071 * using the pre-allocated buffer or the transfer is too large.
4073 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
4074 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
4075 GFP_KERNEL | GFP_DMA);
4082 spi_message_init(&message);
4083 memset(x, 0, sizeof(x));
4086 spi_message_add_tail(&x[0], &message);
4090 spi_message_add_tail(&x[1], &message);
4093 memcpy(local_buf, txbuf, n_tx);
4094 x[0].tx_buf = local_buf;
4095 x[1].rx_buf = local_buf + n_tx;
4098 status = spi_sync(spi, &message);
4100 memcpy(rxbuf, x[1].rx_buf, n_rx);
4102 if (x[0].tx_buf == buf)
4103 mutex_unlock(&lock);
4109 EXPORT_SYMBOL_GPL(spi_write_then_read);
4111 /*-------------------------------------------------------------------------*/
4113 #if IS_ENABLED(CONFIG_OF)
4114 /* must call put_device() when done with returned spi_device device */
4115 struct spi_device *of_find_spi_device_by_node(struct device_node *node)
4117 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
4119 return dev ? to_spi_device(dev) : NULL;
4121 EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
4122 #endif /* IS_ENABLED(CONFIG_OF) */
4124 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
4125 /* the spi controllers are not using spi_bus, so we find it with another way */
4126 static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
4130 dev = class_find_device_by_of_node(&spi_master_class, node);
4131 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4132 dev = class_find_device_by_of_node(&spi_slave_class, node);
4136 /* reference got in class_find_device */
4137 return container_of(dev, struct spi_controller, dev);
4140 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
4143 struct of_reconfig_data *rd = arg;
4144 struct spi_controller *ctlr;
4145 struct spi_device *spi;
4147 switch (of_reconfig_get_state_change(action, arg)) {
4148 case OF_RECONFIG_CHANGE_ADD:
4149 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
4151 return NOTIFY_OK; /* not for us */
4153 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
4154 put_device(&ctlr->dev);
4158 spi = of_register_spi_device(ctlr, rd->dn);
4159 put_device(&ctlr->dev);
4162 pr_err("%s: failed to create for '%pOF'\n",
4164 of_node_clear_flag(rd->dn, OF_POPULATED);
4165 return notifier_from_errno(PTR_ERR(spi));
4169 case OF_RECONFIG_CHANGE_REMOVE:
4170 /* already depopulated? */
4171 if (!of_node_check_flag(rd->dn, OF_POPULATED))
4174 /* find our device by node */
4175 spi = of_find_spi_device_by_node(rd->dn);
4177 return NOTIFY_OK; /* no? not meant for us */
4179 /* unregister takes one ref away */
4180 spi_unregister_device(spi);
4182 /* and put the reference of the find */
4183 put_device(&spi->dev);
4190 static struct notifier_block spi_of_notifier = {
4191 .notifier_call = of_spi_notify,
4193 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4194 extern struct notifier_block spi_of_notifier;
4195 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4197 #if IS_ENABLED(CONFIG_ACPI)
4198 static int spi_acpi_controller_match(struct device *dev, const void *data)
4200 return ACPI_COMPANION(dev->parent) == data;
4203 static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4207 dev = class_find_device(&spi_master_class, NULL, adev,
4208 spi_acpi_controller_match);
4209 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4210 dev = class_find_device(&spi_slave_class, NULL, adev,
4211 spi_acpi_controller_match);
4215 return container_of(dev, struct spi_controller, dev);
4218 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4222 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4223 return to_spi_device(dev);
4226 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4229 struct acpi_device *adev = arg;
4230 struct spi_controller *ctlr;
4231 struct spi_device *spi;
4234 case ACPI_RECONFIG_DEVICE_ADD:
4235 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
4239 acpi_register_spi_device(ctlr, adev);
4240 put_device(&ctlr->dev);
4242 case ACPI_RECONFIG_DEVICE_REMOVE:
4243 if (!acpi_device_enumerated(adev))
4246 spi = acpi_spi_find_device_by_adev(adev);
4250 spi_unregister_device(spi);
4251 put_device(&spi->dev);
4258 static struct notifier_block spi_acpi_notifier = {
4259 .notifier_call = acpi_spi_notify,
4262 extern struct notifier_block spi_acpi_notifier;
4265 static int __init spi_init(void)
4269 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4275 status = bus_register(&spi_bus_type);
4279 status = class_register(&spi_master_class);
4283 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4284 status = class_register(&spi_slave_class);
4289 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4290 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4291 if (IS_ENABLED(CONFIG_ACPI))
4292 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4297 class_unregister(&spi_master_class);
4299 bus_unregister(&spi_bus_type);
4307 /* board_info is normally registered in arch_initcall(),
4308 * but even essential drivers wait till later
4310 * REVISIT only boardinfo really needs static linking. the rest (device and
4311 * driver registration) _could_ be dynamically linked (modular) ... costs
4312 * include needing to have boardinfo data structures be much more public.
4314 postcore_initcall(spi_init);