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 controllers may cleanup for released devices */
51 if (spi->controller->cleanup)
52 spi->controller->cleanup(spi);
54 spi_controller_put(spi->controller);
55 kfree(spi->driver_override);
60 modalias_show(struct device *dev, struct device_attribute *a, char *buf)
62 const struct spi_device *spi = to_spi_device(dev);
65 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
69 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
71 static DEVICE_ATTR_RO(modalias);
73 static ssize_t driver_override_store(struct device *dev,
74 struct device_attribute *a,
75 const char *buf, size_t count)
77 struct spi_device *spi = to_spi_device(dev);
78 const char *end = memchr(buf, '\n', count);
79 const size_t len = end ? end - buf : count;
80 const char *driver_override, *old;
82 /* We need to keep extra room for a newline when displaying value */
83 if (len >= (PAGE_SIZE - 1))
86 driver_override = kstrndup(buf, len, GFP_KERNEL);
91 old = spi->driver_override;
93 spi->driver_override = driver_override;
95 /* Empty string, disable driver override */
96 spi->driver_override = NULL;
97 kfree(driver_override);
105 static ssize_t driver_override_show(struct device *dev,
106 struct device_attribute *a, char *buf)
108 const struct spi_device *spi = to_spi_device(dev);
112 len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
116 static DEVICE_ATTR_RW(driver_override);
118 #define SPI_STATISTICS_ATTRS(field, file) \
119 static ssize_t spi_controller_##field##_show(struct device *dev, \
120 struct device_attribute *attr, \
123 struct spi_controller *ctlr = container_of(dev, \
124 struct spi_controller, dev); \
125 return spi_statistics_##field##_show(&ctlr->statistics, buf); \
127 static struct device_attribute dev_attr_spi_controller_##field = { \
128 .attr = { .name = file, .mode = 0444 }, \
129 .show = spi_controller_##field##_show, \
131 static ssize_t spi_device_##field##_show(struct device *dev, \
132 struct device_attribute *attr, \
135 struct spi_device *spi = to_spi_device(dev); \
136 return spi_statistics_##field##_show(&spi->statistics, buf); \
138 static struct device_attribute dev_attr_spi_device_##field = { \
139 .attr = { .name = file, .mode = 0444 }, \
140 .show = spi_device_##field##_show, \
143 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
144 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
147 unsigned long flags; \
149 spin_lock_irqsave(&stat->lock, flags); \
150 len = sprintf(buf, format_string, stat->field); \
151 spin_unlock_irqrestore(&stat->lock, flags); \
154 SPI_STATISTICS_ATTRS(name, file)
156 #define SPI_STATISTICS_SHOW(field, format_string) \
157 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
158 field, format_string)
160 SPI_STATISTICS_SHOW(messages, "%lu");
161 SPI_STATISTICS_SHOW(transfers, "%lu");
162 SPI_STATISTICS_SHOW(errors, "%lu");
163 SPI_STATISTICS_SHOW(timedout, "%lu");
165 SPI_STATISTICS_SHOW(spi_sync, "%lu");
166 SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
167 SPI_STATISTICS_SHOW(spi_async, "%lu");
169 SPI_STATISTICS_SHOW(bytes, "%llu");
170 SPI_STATISTICS_SHOW(bytes_rx, "%llu");
171 SPI_STATISTICS_SHOW(bytes_tx, "%llu");
173 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
174 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
175 "transfer_bytes_histo_" number, \
176 transfer_bytes_histo[index], "%lu")
177 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
178 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
179 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
180 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
181 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
182 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
183 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
184 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
185 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
186 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
187 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
188 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
189 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
190 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
191 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
192 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
193 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
195 SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
197 static struct attribute *spi_dev_attrs[] = {
198 &dev_attr_modalias.attr,
199 &dev_attr_driver_override.attr,
203 static const struct attribute_group spi_dev_group = {
204 .attrs = spi_dev_attrs,
207 static struct attribute *spi_device_statistics_attrs[] = {
208 &dev_attr_spi_device_messages.attr,
209 &dev_attr_spi_device_transfers.attr,
210 &dev_attr_spi_device_errors.attr,
211 &dev_attr_spi_device_timedout.attr,
212 &dev_attr_spi_device_spi_sync.attr,
213 &dev_attr_spi_device_spi_sync_immediate.attr,
214 &dev_attr_spi_device_spi_async.attr,
215 &dev_attr_spi_device_bytes.attr,
216 &dev_attr_spi_device_bytes_rx.attr,
217 &dev_attr_spi_device_bytes_tx.attr,
218 &dev_attr_spi_device_transfer_bytes_histo0.attr,
219 &dev_attr_spi_device_transfer_bytes_histo1.attr,
220 &dev_attr_spi_device_transfer_bytes_histo2.attr,
221 &dev_attr_spi_device_transfer_bytes_histo3.attr,
222 &dev_attr_spi_device_transfer_bytes_histo4.attr,
223 &dev_attr_spi_device_transfer_bytes_histo5.attr,
224 &dev_attr_spi_device_transfer_bytes_histo6.attr,
225 &dev_attr_spi_device_transfer_bytes_histo7.attr,
226 &dev_attr_spi_device_transfer_bytes_histo8.attr,
227 &dev_attr_spi_device_transfer_bytes_histo9.attr,
228 &dev_attr_spi_device_transfer_bytes_histo10.attr,
229 &dev_attr_spi_device_transfer_bytes_histo11.attr,
230 &dev_attr_spi_device_transfer_bytes_histo12.attr,
231 &dev_attr_spi_device_transfer_bytes_histo13.attr,
232 &dev_attr_spi_device_transfer_bytes_histo14.attr,
233 &dev_attr_spi_device_transfer_bytes_histo15.attr,
234 &dev_attr_spi_device_transfer_bytes_histo16.attr,
235 &dev_attr_spi_device_transfers_split_maxsize.attr,
239 static const struct attribute_group spi_device_statistics_group = {
240 .name = "statistics",
241 .attrs = spi_device_statistics_attrs,
244 static const struct attribute_group *spi_dev_groups[] = {
246 &spi_device_statistics_group,
250 static struct attribute *spi_controller_statistics_attrs[] = {
251 &dev_attr_spi_controller_messages.attr,
252 &dev_attr_spi_controller_transfers.attr,
253 &dev_attr_spi_controller_errors.attr,
254 &dev_attr_spi_controller_timedout.attr,
255 &dev_attr_spi_controller_spi_sync.attr,
256 &dev_attr_spi_controller_spi_sync_immediate.attr,
257 &dev_attr_spi_controller_spi_async.attr,
258 &dev_attr_spi_controller_bytes.attr,
259 &dev_attr_spi_controller_bytes_rx.attr,
260 &dev_attr_spi_controller_bytes_tx.attr,
261 &dev_attr_spi_controller_transfer_bytes_histo0.attr,
262 &dev_attr_spi_controller_transfer_bytes_histo1.attr,
263 &dev_attr_spi_controller_transfer_bytes_histo2.attr,
264 &dev_attr_spi_controller_transfer_bytes_histo3.attr,
265 &dev_attr_spi_controller_transfer_bytes_histo4.attr,
266 &dev_attr_spi_controller_transfer_bytes_histo5.attr,
267 &dev_attr_spi_controller_transfer_bytes_histo6.attr,
268 &dev_attr_spi_controller_transfer_bytes_histo7.attr,
269 &dev_attr_spi_controller_transfer_bytes_histo8.attr,
270 &dev_attr_spi_controller_transfer_bytes_histo9.attr,
271 &dev_attr_spi_controller_transfer_bytes_histo10.attr,
272 &dev_attr_spi_controller_transfer_bytes_histo11.attr,
273 &dev_attr_spi_controller_transfer_bytes_histo12.attr,
274 &dev_attr_spi_controller_transfer_bytes_histo13.attr,
275 &dev_attr_spi_controller_transfer_bytes_histo14.attr,
276 &dev_attr_spi_controller_transfer_bytes_histo15.attr,
277 &dev_attr_spi_controller_transfer_bytes_histo16.attr,
278 &dev_attr_spi_controller_transfers_split_maxsize.attr,
282 static const struct attribute_group spi_controller_statistics_group = {
283 .name = "statistics",
284 .attrs = spi_controller_statistics_attrs,
287 static const struct attribute_group *spi_master_groups[] = {
288 &spi_controller_statistics_group,
292 void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
293 struct spi_transfer *xfer,
294 struct spi_controller *ctlr)
297 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
302 spin_lock_irqsave(&stats->lock, flags);
305 stats->transfer_bytes_histo[l2len]++;
307 stats->bytes += xfer->len;
308 if ((xfer->tx_buf) &&
309 (xfer->tx_buf != ctlr->dummy_tx))
310 stats->bytes_tx += xfer->len;
311 if ((xfer->rx_buf) &&
312 (xfer->rx_buf != ctlr->dummy_rx))
313 stats->bytes_rx += xfer->len;
315 spin_unlock_irqrestore(&stats->lock, flags);
317 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
319 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
320 * and the sysfs version makes coldplug work too.
323 static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
324 const struct spi_device *sdev)
326 while (id->name[0]) {
327 if (!strcmp(sdev->modalias, id->name))
334 const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
336 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
338 return spi_match_id(sdrv->id_table, sdev);
340 EXPORT_SYMBOL_GPL(spi_get_device_id);
342 static int spi_match_device(struct device *dev, struct device_driver *drv)
344 const struct spi_device *spi = to_spi_device(dev);
345 const struct spi_driver *sdrv = to_spi_driver(drv);
347 /* Check override first, and if set, only use the named driver */
348 if (spi->driver_override)
349 return strcmp(spi->driver_override, drv->name) == 0;
351 /* Attempt an OF style match */
352 if (of_driver_match_device(dev, drv))
356 if (acpi_driver_match_device(dev, drv))
360 return !!spi_match_id(sdrv->id_table, spi);
362 return strcmp(spi->modalias, drv->name) == 0;
365 static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
367 const struct spi_device *spi = to_spi_device(dev);
370 rc = acpi_device_uevent_modalias(dev, env);
374 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
377 struct bus_type spi_bus_type = {
379 .dev_groups = spi_dev_groups,
380 .match = spi_match_device,
381 .uevent = spi_uevent,
383 EXPORT_SYMBOL_GPL(spi_bus_type);
386 static int spi_drv_probe(struct device *dev)
388 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
389 struct spi_device *spi = to_spi_device(dev);
392 ret = of_clk_set_defaults(dev->of_node, false);
397 spi->irq = of_irq_get(dev->of_node, 0);
398 if (spi->irq == -EPROBE_DEFER)
399 return -EPROBE_DEFER;
404 ret = dev_pm_domain_attach(dev, true);
408 ret = sdrv->probe(spi);
410 dev_pm_domain_detach(dev, true);
415 static int spi_drv_remove(struct device *dev)
417 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
420 ret = sdrv->remove(to_spi_device(dev));
421 dev_pm_domain_detach(dev, true);
426 static void spi_drv_shutdown(struct device *dev)
428 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
430 sdrv->shutdown(to_spi_device(dev));
434 * __spi_register_driver - register a SPI driver
435 * @owner: owner module of the driver to register
436 * @sdrv: the driver to register
439 * Return: zero on success, else a negative error code.
441 int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
443 sdrv->driver.owner = owner;
444 sdrv->driver.bus = &spi_bus_type;
446 sdrv->driver.probe = spi_drv_probe;
448 sdrv->driver.remove = spi_drv_remove;
450 sdrv->driver.shutdown = spi_drv_shutdown;
451 return driver_register(&sdrv->driver);
453 EXPORT_SYMBOL_GPL(__spi_register_driver);
455 /*-------------------------------------------------------------------------*/
457 /* SPI devices should normally not be created by SPI device drivers; that
458 * would make them board-specific. Similarly with SPI controller drivers.
459 * Device registration normally goes into like arch/.../mach.../board-YYY.c
460 * with other readonly (flashable) information about mainboard devices.
464 struct list_head list;
465 struct spi_board_info board_info;
468 static LIST_HEAD(board_list);
469 static LIST_HEAD(spi_controller_list);
472 * Used to protect add/del operation for board_info list and
473 * spi_controller list, and their matching process
474 * also used to protect object of type struct idr
476 static DEFINE_MUTEX(board_lock);
479 * Prevents addition of devices with same chip select and
480 * addition of devices below an unregistering controller.
482 static DEFINE_MUTEX(spi_add_lock);
485 * spi_alloc_device - Allocate a new SPI device
486 * @ctlr: Controller to which device is connected
489 * Allows a driver to allocate and initialize a spi_device without
490 * registering it immediately. This allows a driver to directly
491 * fill the spi_device with device parameters before calling
492 * spi_add_device() on it.
494 * Caller is responsible to call spi_add_device() on the returned
495 * spi_device structure to add it to the SPI controller. If the caller
496 * needs to discard the spi_device without adding it, then it should
497 * call spi_dev_put() on it.
499 * Return: a pointer to the new device, or NULL.
501 struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
503 struct spi_device *spi;
505 if (!spi_controller_get(ctlr))
508 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
510 spi_controller_put(ctlr);
514 spi->master = spi->controller = ctlr;
515 spi->dev.parent = &ctlr->dev;
516 spi->dev.bus = &spi_bus_type;
517 spi->dev.release = spidev_release;
518 spi->cs_gpio = -ENOENT;
519 spi->mode = ctlr->buswidth_override_bits;
521 spin_lock_init(&spi->statistics.lock);
523 device_initialize(&spi->dev);
526 EXPORT_SYMBOL_GPL(spi_alloc_device);
528 static void spi_dev_set_name(struct spi_device *spi)
530 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
533 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
537 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
541 static int spi_dev_check(struct device *dev, void *data)
543 struct spi_device *spi = to_spi_device(dev);
544 struct spi_device *new_spi = data;
546 if (spi->controller == new_spi->controller &&
547 spi->chip_select == new_spi->chip_select)
553 * spi_add_device - Add spi_device allocated with spi_alloc_device
554 * @spi: spi_device to register
556 * Companion function to spi_alloc_device. Devices allocated with
557 * spi_alloc_device can be added onto the spi bus with this function.
559 * Return: 0 on success; negative errno on failure
561 int spi_add_device(struct spi_device *spi)
563 struct spi_controller *ctlr = spi->controller;
564 struct device *dev = ctlr->dev.parent;
567 /* Chipselects are numbered 0..max; validate. */
568 if (spi->chip_select >= ctlr->num_chipselect) {
569 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
570 ctlr->num_chipselect);
574 /* Set the bus ID string */
575 spi_dev_set_name(spi);
577 /* We need to make sure there's no other device with this
578 * chipselect **BEFORE** we call setup(), else we'll trash
579 * its configuration. Lock against concurrent add() calls.
581 mutex_lock(&spi_add_lock);
583 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
585 dev_err(dev, "chipselect %d already in use\n",
590 /* Controller may unregister concurrently */
591 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
592 !device_is_registered(&ctlr->dev)) {
597 /* Descriptors take precedence */
599 spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
600 else if (ctlr->cs_gpios)
601 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
603 /* Drivers may modify this initial i/o setup, but will
604 * normally rely on the device being setup. Devices
605 * using SPI_CS_HIGH can't coexist well otherwise...
607 status = spi_setup(spi);
609 dev_err(dev, "can't setup %s, status %d\n",
610 dev_name(&spi->dev), status);
614 /* Device may be bound to an active driver when this returns */
615 status = device_add(&spi->dev);
617 dev_err(dev, "can't add %s, status %d\n",
618 dev_name(&spi->dev), status);
620 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
623 mutex_unlock(&spi_add_lock);
626 EXPORT_SYMBOL_GPL(spi_add_device);
629 * spi_new_device - instantiate one new SPI device
630 * @ctlr: Controller to which device is connected
631 * @chip: Describes the SPI device
634 * On typical mainboards, this is purely internal; and it's not needed
635 * after board init creates the hard-wired devices. Some development
636 * platforms may not be able to use spi_register_board_info though, and
637 * this is exported so that for example a USB or parport based adapter
638 * driver could add devices (which it would learn about out-of-band).
640 * Return: the new device, or NULL.
642 struct spi_device *spi_new_device(struct spi_controller *ctlr,
643 struct spi_board_info *chip)
645 struct spi_device *proxy;
648 /* NOTE: caller did any chip->bus_num checks necessary.
650 * Also, unless we change the return value convention to use
651 * error-or-pointer (not NULL-or-pointer), troubleshootability
652 * suggests syslogged diagnostics are best here (ugh).
655 proxy = spi_alloc_device(ctlr);
659 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
661 proxy->chip_select = chip->chip_select;
662 proxy->max_speed_hz = chip->max_speed_hz;
663 proxy->mode = chip->mode;
664 proxy->irq = chip->irq;
665 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
666 proxy->dev.platform_data = (void *) chip->platform_data;
667 proxy->controller_data = chip->controller_data;
668 proxy->controller_state = NULL;
670 if (chip->properties) {
671 status = device_add_properties(&proxy->dev, chip->properties);
674 "failed to add properties to '%s': %d\n",
675 chip->modalias, status);
680 status = spi_add_device(proxy);
682 goto err_remove_props;
687 if (chip->properties)
688 device_remove_properties(&proxy->dev);
693 EXPORT_SYMBOL_GPL(spi_new_device);
696 * spi_unregister_device - unregister a single SPI device
697 * @spi: spi_device to unregister
699 * Start making the passed SPI device vanish. Normally this would be handled
700 * by spi_unregister_controller().
702 void spi_unregister_device(struct spi_device *spi)
707 if (spi->dev.of_node) {
708 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
709 of_node_put(spi->dev.of_node);
711 if (ACPI_COMPANION(&spi->dev))
712 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
713 device_unregister(&spi->dev);
715 EXPORT_SYMBOL_GPL(spi_unregister_device);
717 static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
718 struct spi_board_info *bi)
720 struct spi_device *dev;
722 if (ctlr->bus_num != bi->bus_num)
725 dev = spi_new_device(ctlr, bi);
727 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
732 * spi_register_board_info - register SPI devices for a given board
733 * @info: array of chip descriptors
734 * @n: how many descriptors are provided
737 * Board-specific early init code calls this (probably during arch_initcall)
738 * with segments of the SPI device table. Any device nodes are created later,
739 * after the relevant parent SPI controller (bus_num) is defined. We keep
740 * this table of devices forever, so that reloading a controller driver will
741 * not make Linux forget about these hard-wired devices.
743 * Other code can also call this, e.g. a particular add-on board might provide
744 * SPI devices through its expansion connector, so code initializing that board
745 * would naturally declare its SPI devices.
747 * The board info passed can safely be __initdata ... but be careful of
748 * any embedded pointers (platform_data, etc), they're copied as-is.
749 * Device properties are deep-copied though.
751 * Return: zero on success, else a negative error code.
753 int spi_register_board_info(struct spi_board_info const *info, unsigned n)
755 struct boardinfo *bi;
761 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
765 for (i = 0; i < n; i++, bi++, info++) {
766 struct spi_controller *ctlr;
768 memcpy(&bi->board_info, info, sizeof(*info));
769 if (info->properties) {
770 bi->board_info.properties =
771 property_entries_dup(info->properties);
772 if (IS_ERR(bi->board_info.properties))
773 return PTR_ERR(bi->board_info.properties);
776 mutex_lock(&board_lock);
777 list_add_tail(&bi->list, &board_list);
778 list_for_each_entry(ctlr, &spi_controller_list, list)
779 spi_match_controller_to_boardinfo(ctlr,
781 mutex_unlock(&board_lock);
787 /*-------------------------------------------------------------------------*/
789 static void spi_set_cs(struct spi_device *spi, bool enable)
791 bool enable1 = enable;
794 * Avoid calling into the driver (or doing delays) if the chip select
795 * isn't actually changing from the last time this was called.
797 if ((spi->controller->last_cs_enable == enable) &&
798 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
801 spi->controller->last_cs_enable = enable;
802 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
804 if (!spi->controller->set_cs_timing) {
806 spi_delay_exec(&spi->controller->cs_setup, NULL);
808 spi_delay_exec(&spi->controller->cs_hold, NULL);
811 if (spi->mode & SPI_CS_HIGH)
814 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
816 * Honour the SPI_NO_CS flag and invert the enable line, as
817 * active low is default for SPI. Execution paths that handle
818 * polarity inversion in gpiolib (such as device tree) will
819 * enforce active high using the SPI_CS_HIGH resulting in a
820 * double inversion through the code above.
822 if (!(spi->mode & SPI_NO_CS)) {
824 gpiod_set_value_cansleep(spi->cs_gpiod,
827 gpio_set_value_cansleep(spi->cs_gpio, !enable);
829 /* Some SPI masters need both GPIO CS & slave_select */
830 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
831 spi->controller->set_cs)
832 spi->controller->set_cs(spi, !enable);
833 } else if (spi->controller->set_cs) {
834 spi->controller->set_cs(spi, !enable);
837 if (!spi->controller->set_cs_timing) {
839 spi_delay_exec(&spi->controller->cs_inactive, NULL);
843 #ifdef CONFIG_HAS_DMA
844 int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
845 struct sg_table *sgt, void *buf, size_t len,
846 enum dma_data_direction dir)
848 const bool vmalloced_buf = is_vmalloc_addr(buf);
849 unsigned int max_seg_size = dma_get_max_seg_size(dev);
850 #ifdef CONFIG_HIGHMEM
851 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
852 (unsigned long)buf < (PKMAP_BASE +
853 (LAST_PKMAP * PAGE_SIZE)));
855 const bool kmap_buf = false;
859 struct page *vm_page;
860 struct scatterlist *sg;
865 if (vmalloced_buf || kmap_buf) {
866 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
867 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
868 } else if (virt_addr_valid(buf)) {
869 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
870 sgs = DIV_ROUND_UP(len, desc_len);
875 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
880 for (i = 0; i < sgs; i++) {
882 if (vmalloced_buf || kmap_buf) {
884 * Next scatterlist entry size is the minimum between
885 * the desc_len and the remaining buffer length that
888 min = min_t(size_t, desc_len,
890 PAGE_SIZE - offset_in_page(buf)));
892 vm_page = vmalloc_to_page(buf);
894 vm_page = kmap_to_page(buf);
899 sg_set_page(sg, vm_page,
900 min, offset_in_page(buf));
902 min = min_t(size_t, len, desc_len);
904 sg_set_buf(sg, sg_buf, min);
912 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
925 void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
926 struct sg_table *sgt, enum dma_data_direction dir)
928 if (sgt->orig_nents) {
929 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
934 static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
936 struct device *tx_dev, *rx_dev;
937 struct spi_transfer *xfer;
944 tx_dev = ctlr->dma_tx->device->dev;
946 tx_dev = ctlr->dev.parent;
949 rx_dev = ctlr->dma_rx->device->dev;
951 rx_dev = ctlr->dev.parent;
953 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
954 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
957 if (xfer->tx_buf != NULL) {
958 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
959 (void *)xfer->tx_buf, xfer->len,
965 if (xfer->rx_buf != NULL) {
966 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
967 xfer->rx_buf, xfer->len,
970 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
977 ctlr->cur_msg_mapped = true;
982 static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
984 struct spi_transfer *xfer;
985 struct device *tx_dev, *rx_dev;
987 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
991 tx_dev = ctlr->dma_tx->device->dev;
993 tx_dev = ctlr->dev.parent;
996 rx_dev = ctlr->dma_rx->device->dev;
998 rx_dev = ctlr->dev.parent;
1000 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1001 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1004 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1005 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1008 ctlr->cur_msg_mapped = false;
1012 #else /* !CONFIG_HAS_DMA */
1013 static inline int __spi_map_msg(struct spi_controller *ctlr,
1014 struct spi_message *msg)
1019 static inline int __spi_unmap_msg(struct spi_controller *ctlr,
1020 struct spi_message *msg)
1024 #endif /* !CONFIG_HAS_DMA */
1026 static inline int spi_unmap_msg(struct spi_controller *ctlr,
1027 struct spi_message *msg)
1029 struct spi_transfer *xfer;
1031 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1033 * Restore the original value of tx_buf or rx_buf if they are
1036 if (xfer->tx_buf == ctlr->dummy_tx)
1037 xfer->tx_buf = NULL;
1038 if (xfer->rx_buf == ctlr->dummy_rx)
1039 xfer->rx_buf = NULL;
1042 return __spi_unmap_msg(ctlr, msg);
1045 static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1047 struct spi_transfer *xfer;
1049 unsigned int max_tx, max_rx;
1051 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1052 && !(msg->spi->mode & SPI_3WIRE)) {
1056 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1057 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1059 max_tx = max(xfer->len, max_tx);
1060 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1062 max_rx = max(xfer->len, max_rx);
1066 tmp = krealloc(ctlr->dummy_tx, max_tx,
1067 GFP_KERNEL | GFP_DMA);
1070 ctlr->dummy_tx = tmp;
1071 memset(tmp, 0, max_tx);
1075 tmp = krealloc(ctlr->dummy_rx, max_rx,
1076 GFP_KERNEL | GFP_DMA);
1079 ctlr->dummy_rx = tmp;
1082 if (max_tx || max_rx) {
1083 list_for_each_entry(xfer, &msg->transfers,
1088 xfer->tx_buf = ctlr->dummy_tx;
1090 xfer->rx_buf = ctlr->dummy_rx;
1095 return __spi_map_msg(ctlr, msg);
1098 static int spi_transfer_wait(struct spi_controller *ctlr,
1099 struct spi_message *msg,
1100 struct spi_transfer *xfer)
1102 struct spi_statistics *statm = &ctlr->statistics;
1103 struct spi_statistics *stats = &msg->spi->statistics;
1104 unsigned long long ms;
1106 if (spi_controller_is_slave(ctlr)) {
1107 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1108 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1112 ms = 8LL * 1000LL * xfer->len;
1113 do_div(ms, xfer->speed_hz);
1114 ms += ms + 200; /* some tolerance */
1119 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1120 msecs_to_jiffies(ms));
1123 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1124 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1125 dev_err(&msg->spi->dev,
1126 "SPI transfer timed out\n");
1134 static void _spi_transfer_delay_ns(u32 ns)
1141 u32 us = DIV_ROUND_UP(ns, 1000);
1146 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1150 int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1152 u32 delay = _delay->value;
1153 u32 unit = _delay->unit;
1160 case SPI_DELAY_UNIT_USECS:
1163 case SPI_DELAY_UNIT_NSECS: /* nothing to do here */
1165 case SPI_DELAY_UNIT_SCK:
1166 /* clock cycles need to be obtained from spi_transfer */
1169 /* if there is no effective speed know, then approximate
1170 * by underestimating with half the requested hz
1172 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1175 delay *= DIV_ROUND_UP(1000000000, hz);
1183 EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1185 int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1194 delay = spi_delay_to_ns(_delay, xfer);
1198 _spi_transfer_delay_ns(delay);
1202 EXPORT_SYMBOL_GPL(spi_delay_exec);
1204 static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1205 struct spi_transfer *xfer)
1207 u32 delay = xfer->cs_change_delay.value;
1208 u32 unit = xfer->cs_change_delay.unit;
1211 /* return early on "fast" mode - for everything but USECS */
1213 if (unit == SPI_DELAY_UNIT_USECS)
1214 _spi_transfer_delay_ns(10000);
1218 ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1220 dev_err_once(&msg->spi->dev,
1221 "Use of unsupported delay unit %i, using default of 10us\n",
1223 _spi_transfer_delay_ns(10000);
1228 * spi_transfer_one_message - Default implementation of transfer_one_message()
1230 * This is a standard implementation of transfer_one_message() for
1231 * drivers which implement a transfer_one() operation. It provides
1232 * standard handling of delays and chip select management.
1234 static int spi_transfer_one_message(struct spi_controller *ctlr,
1235 struct spi_message *msg)
1237 struct spi_transfer *xfer;
1238 bool keep_cs = false;
1240 struct spi_statistics *statm = &ctlr->statistics;
1241 struct spi_statistics *stats = &msg->spi->statistics;
1243 spi_set_cs(msg->spi, true);
1245 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1246 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1248 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1249 trace_spi_transfer_start(msg, xfer);
1251 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1252 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1254 if (!ctlr->ptp_sts_supported) {
1255 xfer->ptp_sts_word_pre = 0;
1256 ptp_read_system_prets(xfer->ptp_sts);
1259 if (xfer->tx_buf || xfer->rx_buf) {
1260 reinit_completion(&ctlr->xfer_completion);
1263 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1265 if (ctlr->cur_msg_mapped &&
1266 (xfer->error & SPI_TRANS_FAIL_NO_START)) {
1267 __spi_unmap_msg(ctlr, msg);
1268 ctlr->fallback = true;
1269 xfer->error &= ~SPI_TRANS_FAIL_NO_START;
1273 SPI_STATISTICS_INCREMENT_FIELD(statm,
1275 SPI_STATISTICS_INCREMENT_FIELD(stats,
1277 dev_err(&msg->spi->dev,
1278 "SPI transfer failed: %d\n", ret);
1283 ret = spi_transfer_wait(ctlr, msg, xfer);
1289 dev_err(&msg->spi->dev,
1290 "Bufferless transfer has length %u\n",
1294 if (!ctlr->ptp_sts_supported) {
1295 ptp_read_system_postts(xfer->ptp_sts);
1296 xfer->ptp_sts_word_post = xfer->len;
1299 trace_spi_transfer_stop(msg, xfer);
1301 if (msg->status != -EINPROGRESS)
1304 spi_transfer_delay_exec(xfer);
1306 if (xfer->cs_change) {
1307 if (list_is_last(&xfer->transfer_list,
1311 spi_set_cs(msg->spi, false);
1312 _spi_transfer_cs_change_delay(msg, xfer);
1313 spi_set_cs(msg->spi, true);
1317 msg->actual_length += xfer->len;
1321 if (ret != 0 || !keep_cs)
1322 spi_set_cs(msg->spi, false);
1324 if (msg->status == -EINPROGRESS)
1327 if (msg->status && ctlr->handle_err)
1328 ctlr->handle_err(ctlr, msg);
1330 spi_res_release(ctlr, msg);
1332 spi_finalize_current_message(ctlr);
1338 * spi_finalize_current_transfer - report completion of a transfer
1339 * @ctlr: the controller reporting completion
1341 * Called by SPI drivers using the core transfer_one_message()
1342 * implementation to notify it that the current interrupt driven
1343 * transfer has finished and the next one may be scheduled.
1345 void spi_finalize_current_transfer(struct spi_controller *ctlr)
1347 complete(&ctlr->xfer_completion);
1349 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1351 static void spi_idle_runtime_pm(struct spi_controller *ctlr)
1353 if (ctlr->auto_runtime_pm) {
1354 pm_runtime_mark_last_busy(ctlr->dev.parent);
1355 pm_runtime_put_autosuspend(ctlr->dev.parent);
1360 * __spi_pump_messages - function which processes spi message queue
1361 * @ctlr: controller to process queue for
1362 * @in_kthread: true if we are in the context of the message pump thread
1364 * This function checks if there is any spi message in the queue that
1365 * needs processing and if so call out to the driver to initialize hardware
1366 * and transfer each message.
1368 * Note that it is called both from the kthread itself and also from
1369 * inside spi_sync(); the queue extraction handling at the top of the
1370 * function should deal with this safely.
1372 static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1374 struct spi_transfer *xfer;
1375 struct spi_message *msg;
1376 bool was_busy = false;
1377 unsigned long flags;
1381 spin_lock_irqsave(&ctlr->queue_lock, flags);
1383 /* Make sure we are not already running a message */
1384 if (ctlr->cur_msg) {
1385 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1389 /* If another context is idling the device then defer */
1391 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1392 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1396 /* Check if the queue is idle */
1397 if (list_empty(&ctlr->queue) || !ctlr->running) {
1399 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1403 /* Defer any non-atomic teardown to the thread */
1405 if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
1406 !ctlr->unprepare_transfer_hardware) {
1407 spi_idle_runtime_pm(ctlr);
1409 trace_spi_controller_idle(ctlr);
1411 kthread_queue_work(ctlr->kworker,
1412 &ctlr->pump_messages);
1414 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1419 ctlr->idling = true;
1420 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1422 kfree(ctlr->dummy_rx);
1423 ctlr->dummy_rx = NULL;
1424 kfree(ctlr->dummy_tx);
1425 ctlr->dummy_tx = NULL;
1426 if (ctlr->unprepare_transfer_hardware &&
1427 ctlr->unprepare_transfer_hardware(ctlr))
1429 "failed to unprepare transfer hardware\n");
1430 spi_idle_runtime_pm(ctlr);
1431 trace_spi_controller_idle(ctlr);
1433 spin_lock_irqsave(&ctlr->queue_lock, flags);
1434 ctlr->idling = false;
1435 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1439 /* Extract head of queue */
1440 msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1441 ctlr->cur_msg = msg;
1443 list_del_init(&msg->queue);
1448 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1450 mutex_lock(&ctlr->io_mutex);
1452 if (!was_busy && ctlr->auto_runtime_pm) {
1453 ret = pm_runtime_get_sync(ctlr->dev.parent);
1455 pm_runtime_put_noidle(ctlr->dev.parent);
1456 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1458 mutex_unlock(&ctlr->io_mutex);
1464 trace_spi_controller_busy(ctlr);
1466 if (!was_busy && ctlr->prepare_transfer_hardware) {
1467 ret = ctlr->prepare_transfer_hardware(ctlr);
1470 "failed to prepare transfer hardware: %d\n",
1473 if (ctlr->auto_runtime_pm)
1474 pm_runtime_put(ctlr->dev.parent);
1477 spi_finalize_current_message(ctlr);
1479 mutex_unlock(&ctlr->io_mutex);
1484 trace_spi_message_start(msg);
1486 if (ctlr->prepare_message) {
1487 ret = ctlr->prepare_message(ctlr, msg);
1489 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1492 spi_finalize_current_message(ctlr);
1495 ctlr->cur_msg_prepared = true;
1498 ret = spi_map_msg(ctlr, msg);
1501 spi_finalize_current_message(ctlr);
1505 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1506 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1507 xfer->ptp_sts_word_pre = 0;
1508 ptp_read_system_prets(xfer->ptp_sts);
1512 ret = ctlr->transfer_one_message(ctlr, msg);
1515 "failed to transfer one message from queue\n");
1520 mutex_unlock(&ctlr->io_mutex);
1522 /* Prod the scheduler in case transfer_one() was busy waiting */
1528 * spi_pump_messages - kthread work function which processes spi message queue
1529 * @work: pointer to kthread work struct contained in the controller struct
1531 static void spi_pump_messages(struct kthread_work *work)
1533 struct spi_controller *ctlr =
1534 container_of(work, struct spi_controller, pump_messages);
1536 __spi_pump_messages(ctlr, true);
1540 * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
1541 * TX timestamp for the requested byte from the SPI
1542 * transfer. The frequency with which this function
1543 * must be called (once per word, once for the whole
1544 * transfer, once per batch of words etc) is arbitrary
1545 * as long as the @tx buffer offset is greater than or
1546 * equal to the requested byte at the time of the
1547 * call. The timestamp is only taken once, at the
1548 * first such call. It is assumed that the driver
1549 * advances its @tx buffer pointer monotonically.
1550 * @ctlr: Pointer to the spi_controller structure of the driver
1551 * @xfer: Pointer to the transfer being timestamped
1552 * @progress: How many words (not bytes) have been transferred so far
1553 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1554 * transfer, for less jitter in time measurement. Only compatible
1555 * with PIO drivers. If true, must follow up with
1556 * spi_take_timestamp_post or otherwise system will crash.
1557 * WARNING: for fully predictable results, the CPU frequency must
1558 * also be under control (governor).
1560 void spi_take_timestamp_pre(struct spi_controller *ctlr,
1561 struct spi_transfer *xfer,
1562 size_t progress, bool irqs_off)
1567 if (xfer->timestamped)
1570 if (progress > xfer->ptp_sts_word_pre)
1573 /* Capture the resolution of the timestamp */
1574 xfer->ptp_sts_word_pre = progress;
1577 local_irq_save(ctlr->irq_flags);
1581 ptp_read_system_prets(xfer->ptp_sts);
1583 EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
1586 * spi_take_timestamp_post - helper for drivers to collect the end of the
1587 * TX timestamp for the requested byte from the SPI
1588 * transfer. Can be called with an arbitrary
1589 * frequency: only the first call where @tx exceeds
1590 * or is equal to the requested word will be
1592 * @ctlr: Pointer to the spi_controller structure of the driver
1593 * @xfer: Pointer to the transfer being timestamped
1594 * @progress: How many words (not bytes) have been transferred so far
1595 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1597 void spi_take_timestamp_post(struct spi_controller *ctlr,
1598 struct spi_transfer *xfer,
1599 size_t progress, bool irqs_off)
1604 if (xfer->timestamped)
1607 if (progress < xfer->ptp_sts_word_post)
1610 ptp_read_system_postts(xfer->ptp_sts);
1613 local_irq_restore(ctlr->irq_flags);
1617 /* Capture the resolution of the timestamp */
1618 xfer->ptp_sts_word_post = progress;
1620 xfer->timestamped = true;
1622 EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
1625 * spi_set_thread_rt - set the controller to pump at realtime priority
1626 * @ctlr: controller to boost priority of
1628 * This can be called because the controller requested realtime priority
1629 * (by setting the ->rt value before calling spi_register_controller()) or
1630 * because a device on the bus said that its transfers needed realtime
1633 * NOTE: at the moment if any device on a bus says it needs realtime then
1634 * the thread will be at realtime priority for all transfers on that
1635 * controller. If this eventually becomes a problem we may see if we can
1636 * find a way to boost the priority only temporarily during relevant
1639 static void spi_set_thread_rt(struct spi_controller *ctlr)
1641 dev_info(&ctlr->dev,
1642 "will run message pump with realtime priority\n");
1643 sched_set_fifo(ctlr->kworker->task);
1646 static int spi_init_queue(struct spi_controller *ctlr)
1648 ctlr->running = false;
1651 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
1652 if (IS_ERR(ctlr->kworker)) {
1653 dev_err(&ctlr->dev, "failed to create message pump kworker\n");
1654 return PTR_ERR(ctlr->kworker);
1657 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1660 * Controller config will indicate if this controller should run the
1661 * message pump with high (realtime) priority to reduce the transfer
1662 * latency on the bus by minimising the delay between a transfer
1663 * request and the scheduling of the message pump thread. Without this
1664 * setting the message pump thread will remain at default priority.
1667 spi_set_thread_rt(ctlr);
1673 * spi_get_next_queued_message() - called by driver to check for queued
1675 * @ctlr: the controller to check for queued messages
1677 * If there are more messages in the queue, the next message is returned from
1680 * Return: the next message in the queue, else NULL if the queue is empty.
1682 struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1684 struct spi_message *next;
1685 unsigned long flags;
1687 /* get a pointer to the next message, if any */
1688 spin_lock_irqsave(&ctlr->queue_lock, flags);
1689 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1691 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1695 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1698 * spi_finalize_current_message() - the current message is complete
1699 * @ctlr: the controller to return the message to
1701 * Called by the driver to notify the core that the message in the front of the
1702 * queue is complete and can be removed from the queue.
1704 void spi_finalize_current_message(struct spi_controller *ctlr)
1706 struct spi_transfer *xfer;
1707 struct spi_message *mesg;
1708 unsigned long flags;
1711 spin_lock_irqsave(&ctlr->queue_lock, flags);
1712 mesg = ctlr->cur_msg;
1713 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1715 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1716 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
1717 ptp_read_system_postts(xfer->ptp_sts);
1718 xfer->ptp_sts_word_post = xfer->len;
1722 if (unlikely(ctlr->ptp_sts_supported))
1723 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
1724 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
1726 spi_unmap_msg(ctlr, mesg);
1728 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1729 ret = ctlr->unprepare_message(ctlr, mesg);
1731 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1736 spin_lock_irqsave(&ctlr->queue_lock, flags);
1737 ctlr->cur_msg = NULL;
1738 ctlr->cur_msg_prepared = false;
1739 ctlr->fallback = false;
1740 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1741 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1743 trace_spi_message_done(mesg);
1747 mesg->complete(mesg->context);
1749 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1751 static int spi_start_queue(struct spi_controller *ctlr)
1753 unsigned long flags;
1755 spin_lock_irqsave(&ctlr->queue_lock, flags);
1757 if (ctlr->running || ctlr->busy) {
1758 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1762 ctlr->running = true;
1763 ctlr->cur_msg = NULL;
1764 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1766 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1771 static int spi_stop_queue(struct spi_controller *ctlr)
1773 unsigned long flags;
1774 unsigned limit = 500;
1777 spin_lock_irqsave(&ctlr->queue_lock, flags);
1780 * This is a bit lame, but is optimized for the common execution path.
1781 * A wait_queue on the ctlr->busy could be used, but then the common
1782 * execution path (pump_messages) would be required to call wake_up or
1783 * friends on every SPI message. Do this instead.
1785 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1786 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1787 usleep_range(10000, 11000);
1788 spin_lock_irqsave(&ctlr->queue_lock, flags);
1791 if (!list_empty(&ctlr->queue) || ctlr->busy)
1794 ctlr->running = false;
1796 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1799 dev_warn(&ctlr->dev, "could not stop message queue\n");
1805 static int spi_destroy_queue(struct spi_controller *ctlr)
1809 ret = spi_stop_queue(ctlr);
1812 * kthread_flush_worker will block until all work is done.
1813 * If the reason that stop_queue timed out is that the work will never
1814 * finish, then it does no good to call flush/stop thread, so
1818 dev_err(&ctlr->dev, "problem destroying queue\n");
1822 kthread_destroy_worker(ctlr->kworker);
1827 static int __spi_queued_transfer(struct spi_device *spi,
1828 struct spi_message *msg,
1831 struct spi_controller *ctlr = spi->controller;
1832 unsigned long flags;
1834 spin_lock_irqsave(&ctlr->queue_lock, flags);
1836 if (!ctlr->running) {
1837 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1840 msg->actual_length = 0;
1841 msg->status = -EINPROGRESS;
1843 list_add_tail(&msg->queue, &ctlr->queue);
1844 if (!ctlr->busy && need_pump)
1845 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1847 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1852 * spi_queued_transfer - transfer function for queued transfers
1853 * @spi: spi device which is requesting transfer
1854 * @msg: spi message which is to handled is queued to driver queue
1856 * Return: zero on success, else a negative error code.
1858 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1860 return __spi_queued_transfer(spi, msg, true);
1863 static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1867 ctlr->transfer = spi_queued_transfer;
1868 if (!ctlr->transfer_one_message)
1869 ctlr->transfer_one_message = spi_transfer_one_message;
1871 /* Initialize and start queue */
1872 ret = spi_init_queue(ctlr);
1874 dev_err(&ctlr->dev, "problem initializing queue\n");
1875 goto err_init_queue;
1877 ctlr->queued = true;
1878 ret = spi_start_queue(ctlr);
1880 dev_err(&ctlr->dev, "problem starting queue\n");
1881 goto err_start_queue;
1887 spi_destroy_queue(ctlr);
1893 * spi_flush_queue - Send all pending messages in the queue from the callers'
1895 * @ctlr: controller to process queue for
1897 * This should be used when one wants to ensure all pending messages have been
1898 * sent before doing something. Is used by the spi-mem code to make sure SPI
1899 * memory operations do not preempt regular SPI transfers that have been queued
1900 * before the spi-mem operation.
1902 void spi_flush_queue(struct spi_controller *ctlr)
1904 if (ctlr->transfer == spi_queued_transfer)
1905 __spi_pump_messages(ctlr, false);
1908 /*-------------------------------------------------------------------------*/
1910 #if defined(CONFIG_OF)
1911 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1912 struct device_node *nc)
1917 /* Mode (clock phase/polarity/etc.) */
1918 if (of_property_read_bool(nc, "spi-cpha"))
1919 spi->mode |= SPI_CPHA;
1920 if (of_property_read_bool(nc, "spi-cpol"))
1921 spi->mode |= SPI_CPOL;
1922 if (of_property_read_bool(nc, "spi-3wire"))
1923 spi->mode |= SPI_3WIRE;
1924 if (of_property_read_bool(nc, "spi-lsb-first"))
1925 spi->mode |= SPI_LSB_FIRST;
1926 if (of_property_read_bool(nc, "spi-cs-high"))
1927 spi->mode |= SPI_CS_HIGH;
1929 /* Device DUAL/QUAD mode */
1930 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1935 spi->mode |= SPI_TX_DUAL;
1938 spi->mode |= SPI_TX_QUAD;
1941 spi->mode |= SPI_TX_OCTAL;
1944 dev_warn(&ctlr->dev,
1945 "spi-tx-bus-width %d not supported\n",
1951 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1956 spi->mode |= SPI_RX_DUAL;
1959 spi->mode |= SPI_RX_QUAD;
1962 spi->mode |= SPI_RX_OCTAL;
1965 dev_warn(&ctlr->dev,
1966 "spi-rx-bus-width %d not supported\n",
1972 if (spi_controller_is_slave(ctlr)) {
1973 if (!of_node_name_eq(nc, "slave")) {
1974 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
1981 /* Device address */
1982 rc = of_property_read_u32(nc, "reg", &value);
1984 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
1988 spi->chip_select = value;
1991 * For descriptors associated with the device, polarity inversion is
1992 * handled in the gpiolib, so all gpio chip selects are "active high"
1993 * in the logical sense, the gpiolib will invert the line if need be.
1995 if ((ctlr->use_gpio_descriptors) && ctlr->cs_gpiods &&
1996 ctlr->cs_gpiods[spi->chip_select])
1997 spi->mode |= SPI_CS_HIGH;
2000 if (!of_property_read_u32(nc, "spi-max-frequency", &value))
2001 spi->max_speed_hz = value;
2006 static struct spi_device *
2007 of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
2009 struct spi_device *spi;
2012 /* Alloc an spi_device */
2013 spi = spi_alloc_device(ctlr);
2015 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
2020 /* Select device driver */
2021 rc = of_modalias_node(nc, spi->modalias,
2022 sizeof(spi->modalias));
2024 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
2028 rc = of_spi_parse_dt(ctlr, spi, nc);
2032 /* Store a pointer to the node in the device structure */
2034 spi->dev.of_node = nc;
2036 /* Register the new device */
2037 rc = spi_add_device(spi);
2039 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
2040 goto err_of_node_put;
2053 * of_register_spi_devices() - Register child devices onto the SPI bus
2054 * @ctlr: Pointer to spi_controller device
2056 * Registers an spi_device for each child node of controller node which
2057 * represents a valid SPI slave.
2059 static void of_register_spi_devices(struct spi_controller *ctlr)
2061 struct spi_device *spi;
2062 struct device_node *nc;
2064 if (!ctlr->dev.of_node)
2067 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2068 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2070 spi = of_register_spi_device(ctlr, nc);
2072 dev_warn(&ctlr->dev,
2073 "Failed to create SPI device for %pOF\n", nc);
2074 of_node_clear_flag(nc, OF_POPULATED);
2079 static void of_register_spi_devices(struct spi_controller *ctlr) { }
2083 struct acpi_spi_lookup {
2084 struct spi_controller *ctlr;
2092 static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2093 struct acpi_spi_lookup *lookup)
2095 const union acpi_object *obj;
2097 if (!x86_apple_machine)
2100 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2101 && obj->buffer.length >= 4)
2102 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2104 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2105 && obj->buffer.length == 8)
2106 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2108 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2109 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2110 lookup->mode |= SPI_LSB_FIRST;
2112 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2113 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2114 lookup->mode |= SPI_CPOL;
2116 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2117 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2118 lookup->mode |= SPI_CPHA;
2121 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2123 struct acpi_spi_lookup *lookup = data;
2124 struct spi_controller *ctlr = lookup->ctlr;
2126 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2127 struct acpi_resource_spi_serialbus *sb;
2128 acpi_handle parent_handle;
2131 sb = &ares->data.spi_serial_bus;
2132 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2134 status = acpi_get_handle(NULL,
2135 sb->resource_source.string_ptr,
2138 if (ACPI_FAILURE(status) ||
2139 ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
2143 * ACPI DeviceSelection numbering is handled by the
2144 * host controller driver in Windows and can vary
2145 * from driver to driver. In Linux we always expect
2146 * 0 .. max - 1 so we need to ask the driver to
2147 * translate between the two schemes.
2149 if (ctlr->fw_translate_cs) {
2150 int cs = ctlr->fw_translate_cs(ctlr,
2151 sb->device_selection);
2154 lookup->chip_select = cs;
2156 lookup->chip_select = sb->device_selection;
2159 lookup->max_speed_hz = sb->connection_speed;
2160 lookup->bits_per_word = sb->data_bit_length;
2162 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2163 lookup->mode |= SPI_CPHA;
2164 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2165 lookup->mode |= SPI_CPOL;
2166 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2167 lookup->mode |= SPI_CS_HIGH;
2169 } else if (lookup->irq < 0) {
2172 if (acpi_dev_resource_interrupt(ares, 0, &r))
2173 lookup->irq = r.start;
2176 /* Always tell the ACPI core to skip this resource */
2180 static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2181 struct acpi_device *adev)
2183 acpi_handle parent_handle = NULL;
2184 struct list_head resource_list;
2185 struct acpi_spi_lookup lookup = {};
2186 struct spi_device *spi;
2189 if (acpi_bus_get_status(adev) || !adev->status.present ||
2190 acpi_device_enumerated(adev))
2196 INIT_LIST_HEAD(&resource_list);
2197 ret = acpi_dev_get_resources(adev, &resource_list,
2198 acpi_spi_add_resource, &lookup);
2199 acpi_dev_free_resource_list(&resource_list);
2202 /* found SPI in _CRS but it points to another controller */
2205 if (!lookup.max_speed_hz &&
2206 !ACPI_FAILURE(acpi_get_parent(adev->handle, &parent_handle)) &&
2207 ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {
2208 /* Apple does not use _CRS but nested devices for SPI slaves */
2209 acpi_spi_parse_apple_properties(adev, &lookup);
2212 if (!lookup.max_speed_hz)
2215 spi = spi_alloc_device(ctlr);
2217 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
2218 dev_name(&adev->dev));
2219 return AE_NO_MEMORY;
2223 ACPI_COMPANION_SET(&spi->dev, adev);
2224 spi->max_speed_hz = lookup.max_speed_hz;
2225 spi->mode |= lookup.mode;
2226 spi->irq = lookup.irq;
2227 spi->bits_per_word = lookup.bits_per_word;
2228 spi->chip_select = lookup.chip_select;
2230 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2231 sizeof(spi->modalias));
2234 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
2236 acpi_device_set_enumerated(adev);
2238 adev->power.flags.ignore_parent = true;
2239 if (spi_add_device(spi)) {
2240 adev->power.flags.ignore_parent = false;
2241 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2242 dev_name(&adev->dev));
2249 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2250 void *data, void **return_value)
2252 struct spi_controller *ctlr = data;
2253 struct acpi_device *adev;
2255 if (acpi_bus_get_device(handle, &adev))
2258 return acpi_register_spi_device(ctlr, adev);
2261 #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2263 static void acpi_register_spi_devices(struct spi_controller *ctlr)
2268 handle = ACPI_HANDLE(ctlr->dev.parent);
2272 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2273 SPI_ACPI_ENUMERATE_MAX_DEPTH,
2274 acpi_spi_add_device, NULL, ctlr, NULL);
2275 if (ACPI_FAILURE(status))
2276 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2279 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2280 #endif /* CONFIG_ACPI */
2282 static void spi_controller_release(struct device *dev)
2284 struct spi_controller *ctlr;
2286 ctlr = container_of(dev, struct spi_controller, dev);
2290 static struct class spi_master_class = {
2291 .name = "spi_master",
2292 .owner = THIS_MODULE,
2293 .dev_release = spi_controller_release,
2294 .dev_groups = spi_master_groups,
2297 #ifdef CONFIG_SPI_SLAVE
2299 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2301 * @spi: device used for the current transfer
2303 int spi_slave_abort(struct spi_device *spi)
2305 struct spi_controller *ctlr = spi->controller;
2307 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
2308 return ctlr->slave_abort(ctlr);
2312 EXPORT_SYMBOL_GPL(spi_slave_abort);
2314 static int match_true(struct device *dev, void *data)
2319 static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2322 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2324 struct device *child;
2326 child = device_find_child(&ctlr->dev, NULL, match_true);
2327 return sprintf(buf, "%s\n",
2328 child ? to_spi_device(child)->modalias : NULL);
2331 static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
2332 const char *buf, size_t count)
2334 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2336 struct spi_device *spi;
2337 struct device *child;
2341 rc = sscanf(buf, "%31s", name);
2342 if (rc != 1 || !name[0])
2345 child = device_find_child(&ctlr->dev, NULL, match_true);
2347 /* Remove registered slave */
2348 device_unregister(child);
2352 if (strcmp(name, "(null)")) {
2353 /* Register new slave */
2354 spi = spi_alloc_device(ctlr);
2358 strlcpy(spi->modalias, name, sizeof(spi->modalias));
2360 rc = spi_add_device(spi);
2370 static DEVICE_ATTR_RW(slave);
2372 static struct attribute *spi_slave_attrs[] = {
2373 &dev_attr_slave.attr,
2377 static const struct attribute_group spi_slave_group = {
2378 .attrs = spi_slave_attrs,
2381 static const struct attribute_group *spi_slave_groups[] = {
2382 &spi_controller_statistics_group,
2387 static struct class spi_slave_class = {
2388 .name = "spi_slave",
2389 .owner = THIS_MODULE,
2390 .dev_release = spi_controller_release,
2391 .dev_groups = spi_slave_groups,
2394 extern struct class spi_slave_class; /* dummy */
2398 * __spi_alloc_controller - allocate an SPI master or slave controller
2399 * @dev: the controller, possibly using the platform_bus
2400 * @size: how much zeroed driver-private data to allocate; the pointer to this
2401 * memory is in the driver_data field of the returned device, accessible
2402 * with spi_controller_get_devdata(); the memory is cacheline aligned;
2403 * drivers granting DMA access to portions of their private data need to
2404 * round up @size using ALIGN(size, dma_get_cache_alignment()).
2405 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2406 * slave (true) controller
2407 * Context: can sleep
2409 * This call is used only by SPI controller drivers, which are the
2410 * only ones directly touching chip registers. It's how they allocate
2411 * an spi_controller structure, prior to calling spi_register_controller().
2413 * This must be called from context that can sleep.
2415 * The caller is responsible for assigning the bus number and initializing the
2416 * controller's methods before calling spi_register_controller(); and (after
2417 * errors adding the device) calling spi_controller_put() to prevent a memory
2420 * Return: the SPI controller structure on success, else NULL.
2422 struct spi_controller *__spi_alloc_controller(struct device *dev,
2423 unsigned int size, bool slave)
2425 struct spi_controller *ctlr;
2426 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
2431 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
2435 device_initialize(&ctlr->dev);
2437 ctlr->num_chipselect = 1;
2438 ctlr->slave = slave;
2439 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2440 ctlr->dev.class = &spi_slave_class;
2442 ctlr->dev.class = &spi_master_class;
2443 ctlr->dev.parent = dev;
2444 pm_suspend_ignore_children(&ctlr->dev, true);
2445 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
2449 EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2452 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2455 struct device_node *np = ctlr->dev.of_node;
2460 nb = of_gpio_named_count(np, "cs-gpios");
2461 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2463 /* Return error only for an incorrectly formed cs-gpios property */
2464 if (nb == 0 || nb == -ENOENT)
2469 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2471 ctlr->cs_gpios = cs;
2473 if (!ctlr->cs_gpios)
2476 for (i = 0; i < ctlr->num_chipselect; i++)
2479 for (i = 0; i < nb; i++)
2480 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2485 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2492 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2493 * @ctlr: The SPI master to grab GPIO descriptors for
2495 static int spi_get_gpio_descs(struct spi_controller *ctlr)
2498 struct gpio_desc **cs;
2499 struct device *dev = &ctlr->dev;
2500 unsigned long native_cs_mask = 0;
2501 unsigned int num_cs_gpios = 0;
2503 nb = gpiod_count(dev, "cs");
2504 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2506 /* No GPIOs at all is fine, else return the error */
2507 if (nb == 0 || nb == -ENOENT)
2512 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
2516 ctlr->cs_gpiods = cs;
2518 for (i = 0; i < nb; i++) {
2520 * Most chipselects are active low, the inverted
2521 * semantics are handled by special quirks in gpiolib,
2522 * so initializing them GPIOD_OUT_LOW here means
2523 * "unasserted", in most cases this will drive the physical
2526 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
2529 return PTR_ERR(cs[i]);
2533 * If we find a CS GPIO, name it after the device and
2538 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
2542 gpiod_set_consumer_name(cs[i], gpioname);
2547 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
2548 dev_err(dev, "Invalid native chip select %d\n", i);
2551 native_cs_mask |= BIT(i);
2554 ctlr->unused_native_cs = ffz(native_cs_mask);
2555 if (num_cs_gpios && ctlr->max_native_cs &&
2556 ctlr->unused_native_cs >= ctlr->max_native_cs) {
2557 dev_err(dev, "No unused native chip select available\n");
2564 static int spi_controller_check_ops(struct spi_controller *ctlr)
2567 * The controller may implement only the high-level SPI-memory like
2568 * operations if it does not support regular SPI transfers, and this is
2570 * If ->mem_ops is NULL, we request that at least one of the
2571 * ->transfer_xxx() method be implemented.
2573 if (ctlr->mem_ops) {
2574 if (!ctlr->mem_ops->exec_op)
2576 } else if (!ctlr->transfer && !ctlr->transfer_one &&
2577 !ctlr->transfer_one_message) {
2585 * spi_register_controller - register SPI master or slave controller
2586 * @ctlr: initialized master, originally from spi_alloc_master() or
2588 * Context: can sleep
2590 * SPI controllers connect to their drivers using some non-SPI bus,
2591 * such as the platform bus. The final stage of probe() in that code
2592 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2594 * SPI controllers use board specific (often SOC specific) bus numbers,
2595 * and board-specific addressing for SPI devices combines those numbers
2596 * with chip select numbers. Since SPI does not directly support dynamic
2597 * device identification, boards need configuration tables telling which
2598 * chip is at which address.
2600 * This must be called from context that can sleep. It returns zero on
2601 * success, else a negative error code (dropping the controller's refcount).
2602 * After a successful return, the caller is responsible for calling
2603 * spi_unregister_controller().
2605 * Return: zero on success, else a negative error code.
2607 int spi_register_controller(struct spi_controller *ctlr)
2609 struct device *dev = ctlr->dev.parent;
2610 struct boardinfo *bi;
2612 int id, first_dynamic;
2618 * Make sure all necessary hooks are implemented before registering
2619 * the SPI controller.
2621 status = spi_controller_check_ops(ctlr);
2625 if (ctlr->bus_num >= 0) {
2626 /* devices with a fixed bus num must check-in with the num */
2627 mutex_lock(&board_lock);
2628 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2629 ctlr->bus_num + 1, GFP_KERNEL);
2630 mutex_unlock(&board_lock);
2631 if (WARN(id < 0, "couldn't get idr"))
2632 return id == -ENOSPC ? -EBUSY : id;
2634 } else if (ctlr->dev.of_node) {
2635 /* allocate dynamic bus number using Linux idr */
2636 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2639 mutex_lock(&board_lock);
2640 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2641 ctlr->bus_num + 1, GFP_KERNEL);
2642 mutex_unlock(&board_lock);
2643 if (WARN(id < 0, "couldn't get idr"))
2644 return id == -ENOSPC ? -EBUSY : id;
2647 if (ctlr->bus_num < 0) {
2648 first_dynamic = of_alias_get_highest_id("spi");
2649 if (first_dynamic < 0)
2654 mutex_lock(&board_lock);
2655 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2657 mutex_unlock(&board_lock);
2658 if (WARN(id < 0, "couldn't get idr"))
2662 INIT_LIST_HEAD(&ctlr->queue);
2663 spin_lock_init(&ctlr->queue_lock);
2664 spin_lock_init(&ctlr->bus_lock_spinlock);
2665 mutex_init(&ctlr->bus_lock_mutex);
2666 mutex_init(&ctlr->io_mutex);
2667 ctlr->bus_lock_flag = 0;
2668 init_completion(&ctlr->xfer_completion);
2669 if (!ctlr->max_dma_len)
2670 ctlr->max_dma_len = INT_MAX;
2672 /* register the device, then userspace will see it.
2673 * registration fails if the bus ID is in use.
2675 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2677 if (!spi_controller_is_slave(ctlr)) {
2678 if (ctlr->use_gpio_descriptors) {
2679 status = spi_get_gpio_descs(ctlr);
2683 * A controller using GPIO descriptors always
2684 * supports SPI_CS_HIGH if need be.
2686 ctlr->mode_bits |= SPI_CS_HIGH;
2688 /* Legacy code path for GPIOs from DT */
2689 status = of_spi_get_gpio_numbers(ctlr);
2696 * Even if it's just one always-selected device, there must
2697 * be at least one chipselect.
2699 if (!ctlr->num_chipselect) {
2704 status = device_add(&ctlr->dev);
2707 dev_dbg(dev, "registered %s %s\n",
2708 spi_controller_is_slave(ctlr) ? "slave" : "master",
2709 dev_name(&ctlr->dev));
2712 * If we're using a queued driver, start the queue. Note that we don't
2713 * need the queueing logic if the driver is only supporting high-level
2714 * memory operations.
2716 if (ctlr->transfer) {
2717 dev_info(dev, "controller is unqueued, this is deprecated\n");
2718 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2719 status = spi_controller_initialize_queue(ctlr);
2721 device_del(&ctlr->dev);
2725 /* add statistics */
2726 spin_lock_init(&ctlr->statistics.lock);
2728 mutex_lock(&board_lock);
2729 list_add_tail(&ctlr->list, &spi_controller_list);
2730 list_for_each_entry(bi, &board_list, list)
2731 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2732 mutex_unlock(&board_lock);
2734 /* Register devices from the device tree and ACPI */
2735 of_register_spi_devices(ctlr);
2736 acpi_register_spi_devices(ctlr);
2740 mutex_lock(&board_lock);
2741 idr_remove(&spi_master_idr, ctlr->bus_num);
2742 mutex_unlock(&board_lock);
2745 EXPORT_SYMBOL_GPL(spi_register_controller);
2747 static void devm_spi_unregister(struct device *dev, void *res)
2749 spi_unregister_controller(*(struct spi_controller **)res);
2753 * devm_spi_register_controller - register managed SPI master or slave
2755 * @dev: device managing SPI controller
2756 * @ctlr: initialized controller, originally from spi_alloc_master() or
2758 * Context: can sleep
2760 * Register a SPI device as with spi_register_controller() which will
2761 * automatically be unregistered and freed.
2763 * Return: zero on success, else a negative error code.
2765 int devm_spi_register_controller(struct device *dev,
2766 struct spi_controller *ctlr)
2768 struct spi_controller **ptr;
2771 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2775 ret = spi_register_controller(ctlr);
2778 devres_add(dev, ptr);
2785 EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2787 static int __unregister(struct device *dev, void *null)
2789 spi_unregister_device(to_spi_device(dev));
2794 * spi_unregister_controller - unregister SPI master or slave controller
2795 * @ctlr: the controller being unregistered
2796 * Context: can sleep
2798 * This call is used only by SPI controller drivers, which are the
2799 * only ones directly touching chip registers.
2801 * This must be called from context that can sleep.
2803 * Note that this function also drops a reference to the controller.
2805 void spi_unregister_controller(struct spi_controller *ctlr)
2807 struct spi_controller *found;
2808 int id = ctlr->bus_num;
2810 /* Prevent addition of new devices, unregister existing ones */
2811 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2812 mutex_lock(&spi_add_lock);
2814 device_for_each_child(&ctlr->dev, NULL, __unregister);
2816 /* First make sure that this controller was ever added */
2817 mutex_lock(&board_lock);
2818 found = idr_find(&spi_master_idr, id);
2819 mutex_unlock(&board_lock);
2821 if (spi_destroy_queue(ctlr))
2822 dev_err(&ctlr->dev, "queue remove failed\n");
2824 mutex_lock(&board_lock);
2825 list_del(&ctlr->list);
2826 mutex_unlock(&board_lock);
2828 device_unregister(&ctlr->dev);
2830 mutex_lock(&board_lock);
2832 idr_remove(&spi_master_idr, id);
2833 mutex_unlock(&board_lock);
2835 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2836 mutex_unlock(&spi_add_lock);
2838 EXPORT_SYMBOL_GPL(spi_unregister_controller);
2840 int spi_controller_suspend(struct spi_controller *ctlr)
2844 /* Basically no-ops for non-queued controllers */
2848 ret = spi_stop_queue(ctlr);
2850 dev_err(&ctlr->dev, "queue stop failed\n");
2854 EXPORT_SYMBOL_GPL(spi_controller_suspend);
2856 int spi_controller_resume(struct spi_controller *ctlr)
2863 ret = spi_start_queue(ctlr);
2865 dev_err(&ctlr->dev, "queue restart failed\n");
2869 EXPORT_SYMBOL_GPL(spi_controller_resume);
2871 static int __spi_controller_match(struct device *dev, const void *data)
2873 struct spi_controller *ctlr;
2874 const u16 *bus_num = data;
2876 ctlr = container_of(dev, struct spi_controller, dev);
2877 return ctlr->bus_num == *bus_num;
2881 * spi_busnum_to_master - look up master associated with bus_num
2882 * @bus_num: the master's bus number
2883 * Context: can sleep
2885 * This call may be used with devices that are registered after
2886 * arch init time. It returns a refcounted pointer to the relevant
2887 * spi_controller (which the caller must release), or NULL if there is
2888 * no such master registered.
2890 * Return: the SPI master structure on success, else NULL.
2892 struct spi_controller *spi_busnum_to_master(u16 bus_num)
2895 struct spi_controller *ctlr = NULL;
2897 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2898 __spi_controller_match);
2900 ctlr = container_of(dev, struct spi_controller, dev);
2901 /* reference got in class_find_device */
2904 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2906 /*-------------------------------------------------------------------------*/
2908 /* Core methods for SPI resource management */
2911 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2912 * during the processing of a spi_message while using
2914 * @spi: the spi device for which we allocate memory
2915 * @release: the release code to execute for this resource
2916 * @size: size to alloc and return
2917 * @gfp: GFP allocation flags
2919 * Return: the pointer to the allocated data
2921 * This may get enhanced in the future to allocate from a memory pool
2922 * of the @spi_device or @spi_controller to avoid repeated allocations.
2924 void *spi_res_alloc(struct spi_device *spi,
2925 spi_res_release_t release,
2926 size_t size, gfp_t gfp)
2928 struct spi_res *sres;
2930 sres = kzalloc(sizeof(*sres) + size, gfp);
2934 INIT_LIST_HEAD(&sres->entry);
2935 sres->release = release;
2939 EXPORT_SYMBOL_GPL(spi_res_alloc);
2942 * spi_res_free - free an spi resource
2943 * @res: pointer to the custom data of a resource
2946 void spi_res_free(void *res)
2948 struct spi_res *sres = container_of(res, struct spi_res, data);
2953 WARN_ON(!list_empty(&sres->entry));
2956 EXPORT_SYMBOL_GPL(spi_res_free);
2959 * spi_res_add - add a spi_res to the spi_message
2960 * @message: the spi message
2961 * @res: the spi_resource
2963 void spi_res_add(struct spi_message *message, void *res)
2965 struct spi_res *sres = container_of(res, struct spi_res, data);
2967 WARN_ON(!list_empty(&sres->entry));
2968 list_add_tail(&sres->entry, &message->resources);
2970 EXPORT_SYMBOL_GPL(spi_res_add);
2973 * spi_res_release - release all spi resources for this message
2974 * @ctlr: the @spi_controller
2975 * @message: the @spi_message
2977 void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
2979 struct spi_res *res, *tmp;
2981 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
2983 res->release(ctlr, message, res->data);
2985 list_del(&res->entry);
2990 EXPORT_SYMBOL_GPL(spi_res_release);
2992 /*-------------------------------------------------------------------------*/
2994 /* Core methods for spi_message alterations */
2996 static void __spi_replace_transfers_release(struct spi_controller *ctlr,
2997 struct spi_message *msg,
3000 struct spi_replaced_transfers *rxfer = res;
3003 /* call extra callback if requested */
3005 rxfer->release(ctlr, msg, res);
3007 /* insert replaced transfers back into the message */
3008 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
3010 /* remove the formerly inserted entries */
3011 for (i = 0; i < rxfer->inserted; i++)
3012 list_del(&rxfer->inserted_transfers[i].transfer_list);
3016 * spi_replace_transfers - replace transfers with several transfers
3017 * and register change with spi_message.resources
3018 * @msg: the spi_message we work upon
3019 * @xfer_first: the first spi_transfer we want to replace
3020 * @remove: number of transfers to remove
3021 * @insert: the number of transfers we want to insert instead
3022 * @release: extra release code necessary in some circumstances
3023 * @extradatasize: extra data to allocate (with alignment guarantees
3024 * of struct @spi_transfer)
3027 * Returns: pointer to @spi_replaced_transfers,
3028 * PTR_ERR(...) in case of errors.
3030 struct spi_replaced_transfers *spi_replace_transfers(
3031 struct spi_message *msg,
3032 struct spi_transfer *xfer_first,
3035 spi_replaced_release_t release,
3036 size_t extradatasize,
3039 struct spi_replaced_transfers *rxfer;
3040 struct spi_transfer *xfer;
3043 /* allocate the structure using spi_res */
3044 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
3045 struct_size(rxfer, inserted_transfers, insert)
3049 return ERR_PTR(-ENOMEM);
3051 /* the release code to invoke before running the generic release */
3052 rxfer->release = release;
3054 /* assign extradata */
3057 &rxfer->inserted_transfers[insert];
3059 /* init the replaced_transfers list */
3060 INIT_LIST_HEAD(&rxfer->replaced_transfers);
3062 /* assign the list_entry after which we should reinsert
3063 * the @replaced_transfers - it may be spi_message.messages!
3065 rxfer->replaced_after = xfer_first->transfer_list.prev;
3067 /* remove the requested number of transfers */
3068 for (i = 0; i < remove; i++) {
3069 /* if the entry after replaced_after it is msg->transfers
3070 * then we have been requested to remove more transfers
3071 * than are in the list
3073 if (rxfer->replaced_after->next == &msg->transfers) {
3074 dev_err(&msg->spi->dev,
3075 "requested to remove more spi_transfers than are available\n");
3076 /* insert replaced transfers back into the message */
3077 list_splice(&rxfer->replaced_transfers,
3078 rxfer->replaced_after);
3080 /* free the spi_replace_transfer structure */
3081 spi_res_free(rxfer);
3083 /* and return with an error */
3084 return ERR_PTR(-EINVAL);
3087 /* remove the entry after replaced_after from list of
3088 * transfers and add it to list of replaced_transfers
3090 list_move_tail(rxfer->replaced_after->next,
3091 &rxfer->replaced_transfers);
3094 /* create copy of the given xfer with identical settings
3095 * based on the first transfer to get removed
3097 for (i = 0; i < insert; i++) {
3098 /* we need to run in reverse order */
3099 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3101 /* copy all spi_transfer data */
3102 memcpy(xfer, xfer_first, sizeof(*xfer));
3105 list_add(&xfer->transfer_list, rxfer->replaced_after);
3107 /* clear cs_change and delay for all but the last */
3109 xfer->cs_change = false;
3110 xfer->delay_usecs = 0;
3111 xfer->delay.value = 0;
3115 /* set up inserted */
3116 rxfer->inserted = insert;
3118 /* and register it with spi_res/spi_message */
3119 spi_res_add(msg, rxfer);
3123 EXPORT_SYMBOL_GPL(spi_replace_transfers);
3125 static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3126 struct spi_message *msg,
3127 struct spi_transfer **xferp,
3131 struct spi_transfer *xfer = *xferp, *xfers;
3132 struct spi_replaced_transfers *srt;
3136 /* calculate how many we have to replace */
3137 count = DIV_ROUND_UP(xfer->len, maxsize);
3139 /* create replacement */
3140 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
3142 return PTR_ERR(srt);
3143 xfers = srt->inserted_transfers;
3145 /* now handle each of those newly inserted spi_transfers
3146 * note that the replacements spi_transfers all are preset
3147 * to the same values as *xferp, so tx_buf, rx_buf and len
3148 * are all identical (as well as most others)
3149 * so we just have to fix up len and the pointers.
3151 * this also includes support for the depreciated
3152 * spi_message.is_dma_mapped interface
3155 /* the first transfer just needs the length modified, so we
3156 * run it outside the loop
3158 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3160 /* all the others need rx_buf/tx_buf also set */
3161 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3162 /* update rx_buf, tx_buf and dma */
3163 if (xfers[i].rx_buf)
3164 xfers[i].rx_buf += offset;
3165 if (xfers[i].rx_dma)
3166 xfers[i].rx_dma += offset;
3167 if (xfers[i].tx_buf)
3168 xfers[i].tx_buf += offset;
3169 if (xfers[i].tx_dma)
3170 xfers[i].tx_dma += offset;
3173 xfers[i].len = min(maxsize, xfers[i].len - offset);
3176 /* we set up xferp to the last entry we have inserted,
3177 * so that we skip those already split transfers
3179 *xferp = &xfers[count - 1];
3181 /* increment statistics counters */
3182 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3183 transfers_split_maxsize);
3184 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
3185 transfers_split_maxsize);
3191 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
3192 * when an individual transfer exceeds a
3194 * @ctlr: the @spi_controller for this transfer
3195 * @msg: the @spi_message to transform
3196 * @maxsize: the maximum when to apply this
3197 * @gfp: GFP allocation flags
3199 * Return: status of transformation
3201 int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3202 struct spi_message *msg,
3206 struct spi_transfer *xfer;
3209 /* iterate over the transfer_list,
3210 * but note that xfer is advanced to the last transfer inserted
3211 * to avoid checking sizes again unnecessarily (also xfer does
3212 * potentiall belong to a different list by the time the
3213 * replacement has happened
3215 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3216 if (xfer->len > maxsize) {
3217 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3226 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3228 /*-------------------------------------------------------------------------*/
3230 /* Core methods for SPI controller protocol drivers. Some of the
3231 * other core methods are currently defined as inline functions.
3234 static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3237 if (ctlr->bits_per_word_mask) {
3238 /* Only 32 bits fit in the mask */
3239 if (bits_per_word > 32)
3241 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3249 * spi_setup - setup SPI mode and clock rate
3250 * @spi: the device whose settings are being modified
3251 * Context: can sleep, and no requests are queued to the device
3253 * SPI protocol drivers may need to update the transfer mode if the
3254 * device doesn't work with its default. They may likewise need
3255 * to update clock rates or word sizes from initial values. This function
3256 * changes those settings, and must be called from a context that can sleep.
3257 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3258 * effect the next time the device is selected and data is transferred to
3259 * or from it. When this function returns, the spi device is deselected.
3261 * Note that this call will fail if the protocol driver specifies an option
3262 * that the underlying controller or its driver does not support. For
3263 * example, not all hardware supports wire transfers using nine bit words,
3264 * LSB-first wire encoding, or active-high chipselects.
3266 * Return: zero on success, else a negative error code.
3268 int spi_setup(struct spi_device *spi)
3270 unsigned bad_bits, ugly_bits;
3273 /* check mode to prevent that DUAL and QUAD set at the same time
3275 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
3276 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
3278 "setup: can not select dual and quad at the same time\n");
3281 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
3283 if ((spi->mode & SPI_3WIRE) && (spi->mode &
3284 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3285 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3287 /* help drivers fail *cleanly* when they need options
3288 * that aren't supported with their current controller
3289 * SPI_CS_WORD has a fallback software implementation,
3290 * so it is ignored here.
3292 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
3293 /* nothing prevents from working with active-high CS in case if it
3294 * is driven by GPIO.
3296 if (gpio_is_valid(spi->cs_gpio))
3297 bad_bits &= ~SPI_CS_HIGH;
3298 ugly_bits = bad_bits &
3299 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3300 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3303 "setup: ignoring unsupported mode bits %x\n",
3305 spi->mode &= ~ugly_bits;
3306 bad_bits &= ~ugly_bits;
3309 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3314 if (!spi->bits_per_word)
3315 spi->bits_per_word = 8;
3317 status = __spi_validate_bits_per_word(spi->controller,
3318 spi->bits_per_word);
3322 if (!spi->max_speed_hz)
3323 spi->max_speed_hz = spi->controller->max_speed_hz;
3325 if (spi->controller->setup)
3326 status = spi->controller->setup(spi);
3328 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
3329 status = pm_runtime_get_sync(spi->controller->dev.parent);
3331 pm_runtime_put_noidle(spi->controller->dev.parent);
3332 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3338 * We do not want to return positive value from pm_runtime_get,
3339 * there are many instances of devices calling spi_setup() and
3340 * checking for a non-zero return value instead of a negative
3345 spi_set_cs(spi, false);
3346 pm_runtime_mark_last_busy(spi->controller->dev.parent);
3347 pm_runtime_put_autosuspend(spi->controller->dev.parent);
3349 spi_set_cs(spi, false);
3352 if (spi->rt && !spi->controller->rt) {
3353 spi->controller->rt = true;
3354 spi_set_thread_rt(spi->controller);
3357 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3358 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
3359 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
3360 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
3361 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
3362 (spi->mode & SPI_LOOP) ? "loopback, " : "",
3363 spi->bits_per_word, spi->max_speed_hz,
3368 EXPORT_SYMBOL_GPL(spi_setup);
3371 * spi_set_cs_timing - configure CS setup, hold, and inactive delays
3372 * @spi: the device that requires specific CS timing configuration
3373 * @setup: CS setup time specified via @spi_delay
3374 * @hold: CS hold time specified via @spi_delay
3375 * @inactive: CS inactive delay between transfers specified via @spi_delay
3377 * Return: zero on success, else a negative error code.
3379 int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup,
3380 struct spi_delay *hold, struct spi_delay *inactive)
3384 if (spi->controller->set_cs_timing)
3385 return spi->controller->set_cs_timing(spi, setup, hold,
3388 if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) ||
3389 (hold && hold->unit == SPI_DELAY_UNIT_SCK) ||
3390 (inactive && inactive->unit == SPI_DELAY_UNIT_SCK)) {
3392 "Clock-cycle delays for CS not supported in SW mode\n");
3396 len = sizeof(struct spi_delay);
3398 /* copy delays to controller */
3400 memcpy(&spi->controller->cs_setup, setup, len);
3402 memset(&spi->controller->cs_setup, 0, len);
3405 memcpy(&spi->controller->cs_hold, hold, len);
3407 memset(&spi->controller->cs_hold, 0, len);
3410 memcpy(&spi->controller->cs_inactive, inactive, len);
3412 memset(&spi->controller->cs_inactive, 0, len);
3416 EXPORT_SYMBOL_GPL(spi_set_cs_timing);
3418 static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
3419 struct spi_device *spi)
3423 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
3427 delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
3431 if (delay1 < delay2)
3432 memcpy(&xfer->word_delay, &spi->word_delay,
3433 sizeof(xfer->word_delay));
3438 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
3440 struct spi_controller *ctlr = spi->controller;
3441 struct spi_transfer *xfer;
3444 if (list_empty(&message->transfers))
3447 /* If an SPI controller does not support toggling the CS line on each
3448 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3449 * for the CS line, we can emulate the CS-per-word hardware function by
3450 * splitting transfers into one-word transfers and ensuring that
3451 * cs_change is set for each transfer.
3453 if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
3455 gpio_is_valid(spi->cs_gpio))) {
3459 maxsize = (spi->bits_per_word + 7) / 8;
3461 /* spi_split_transfers_maxsize() requires message->spi */
3464 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
3469 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3470 /* don't change cs_change on the last entry in the list */
3471 if (list_is_last(&xfer->transfer_list, &message->transfers))
3473 xfer->cs_change = 1;
3477 /* Half-duplex links include original MicroWire, and ones with
3478 * only one data pin like SPI_3WIRE (switches direction) or where
3479 * either MOSI or MISO is missing. They can also be caused by
3480 * software limitations.
3482 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
3483 (spi->mode & SPI_3WIRE)) {
3484 unsigned flags = ctlr->flags;
3486 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3487 if (xfer->rx_buf && xfer->tx_buf)
3489 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
3491 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
3497 * Set transfer bits_per_word and max speed as spi device default if
3498 * it is not set for this transfer.
3499 * Set transfer tx_nbits and rx_nbits as single transfer default
3500 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3501 * Ensure transfer word_delay is at least as long as that required by
3504 message->frame_length = 0;
3505 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3506 xfer->effective_speed_hz = 0;
3507 message->frame_length += xfer->len;
3508 if (!xfer->bits_per_word)
3509 xfer->bits_per_word = spi->bits_per_word;
3511 if (!xfer->speed_hz)
3512 xfer->speed_hz = spi->max_speed_hz;
3514 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
3515 xfer->speed_hz = ctlr->max_speed_hz;
3517 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
3521 * SPI transfer length should be multiple of SPI word size
3522 * where SPI word size should be power-of-two multiple
3524 if (xfer->bits_per_word <= 8)
3526 else if (xfer->bits_per_word <= 16)
3531 /* No partial transfers accepted */
3532 if (xfer->len % w_size)
3535 if (xfer->speed_hz && ctlr->min_speed_hz &&
3536 xfer->speed_hz < ctlr->min_speed_hz)
3539 if (xfer->tx_buf && !xfer->tx_nbits)
3540 xfer->tx_nbits = SPI_NBITS_SINGLE;
3541 if (xfer->rx_buf && !xfer->rx_nbits)
3542 xfer->rx_nbits = SPI_NBITS_SINGLE;
3543 /* check transfer tx/rx_nbits:
3544 * 1. check the value matches one of single, dual and quad
3545 * 2. check tx/rx_nbits match the mode in spi_device
3548 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3549 xfer->tx_nbits != SPI_NBITS_DUAL &&
3550 xfer->tx_nbits != SPI_NBITS_QUAD)
3552 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3553 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3555 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3556 !(spi->mode & SPI_TX_QUAD))
3559 /* check transfer rx_nbits */
3561 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3562 xfer->rx_nbits != SPI_NBITS_DUAL &&
3563 xfer->rx_nbits != SPI_NBITS_QUAD)
3565 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3566 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3568 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3569 !(spi->mode & SPI_RX_QUAD))
3573 if (_spi_xfer_word_delay_update(xfer, spi))
3577 message->status = -EINPROGRESS;
3582 static int __spi_async(struct spi_device *spi, struct spi_message *message)
3584 struct spi_controller *ctlr = spi->controller;
3585 struct spi_transfer *xfer;
3588 * Some controllers do not support doing regular SPI transfers. Return
3589 * ENOTSUPP when this is the case.
3591 if (!ctlr->transfer)
3596 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
3597 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3599 trace_spi_message_submit(message);
3601 if (!ctlr->ptp_sts_supported) {
3602 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3603 xfer->ptp_sts_word_pre = 0;
3604 ptp_read_system_prets(xfer->ptp_sts);
3608 return ctlr->transfer(spi, message);
3612 * spi_async - asynchronous SPI transfer
3613 * @spi: device with which data will be exchanged
3614 * @message: describes the data transfers, including completion callback
3615 * Context: any (irqs may be blocked, etc)
3617 * This call may be used in_irq and other contexts which can't sleep,
3618 * as well as from task contexts which can sleep.
3620 * The completion callback is invoked in a context which can't sleep.
3621 * Before that invocation, the value of message->status is undefined.
3622 * When the callback is issued, message->status holds either zero (to
3623 * indicate complete success) or a negative error code. After that
3624 * callback returns, the driver which issued the transfer request may
3625 * deallocate the associated memory; it's no longer in use by any SPI
3626 * core or controller driver code.
3628 * Note that although all messages to a spi_device are handled in
3629 * FIFO order, messages may go to different devices in other orders.
3630 * Some device might be higher priority, or have various "hard" access
3631 * time requirements, for example.
3633 * On detection of any fault during the transfer, processing of
3634 * the entire message is aborted, and the device is deselected.
3635 * Until returning from the associated message completion callback,
3636 * no other spi_message queued to that device will be processed.
3637 * (This rule applies equally to all the synchronous transfer calls,
3638 * which are wrappers around this core asynchronous primitive.)
3640 * Return: zero on success, else a negative error code.
3642 int spi_async(struct spi_device *spi, struct spi_message *message)
3644 struct spi_controller *ctlr = spi->controller;
3646 unsigned long flags;
3648 ret = __spi_validate(spi, message);
3652 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3654 if (ctlr->bus_lock_flag)
3657 ret = __spi_async(spi, message);
3659 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3663 EXPORT_SYMBOL_GPL(spi_async);
3666 * spi_async_locked - version of spi_async with exclusive bus usage
3667 * @spi: device with which data will be exchanged
3668 * @message: describes the data transfers, including completion callback
3669 * Context: any (irqs may be blocked, etc)
3671 * This call may be used in_irq and other contexts which can't sleep,
3672 * as well as from task contexts which can sleep.
3674 * The completion callback is invoked in a context which can't sleep.
3675 * Before that invocation, the value of message->status is undefined.
3676 * When the callback is issued, message->status holds either zero (to
3677 * indicate complete success) or a negative error code. After that
3678 * callback returns, the driver which issued the transfer request may
3679 * deallocate the associated memory; it's no longer in use by any SPI
3680 * core or controller driver code.
3682 * Note that although all messages to a spi_device are handled in
3683 * FIFO order, messages may go to different devices in other orders.
3684 * Some device might be higher priority, or have various "hard" access
3685 * time requirements, for example.
3687 * On detection of any fault during the transfer, processing of
3688 * the entire message is aborted, and the device is deselected.
3689 * Until returning from the associated message completion callback,
3690 * no other spi_message queued to that device will be processed.
3691 * (This rule applies equally to all the synchronous transfer calls,
3692 * which are wrappers around this core asynchronous primitive.)
3694 * Return: zero on success, else a negative error code.
3696 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3698 struct spi_controller *ctlr = spi->controller;
3700 unsigned long flags;
3702 ret = __spi_validate(spi, message);
3706 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3708 ret = __spi_async(spi, message);
3710 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3715 EXPORT_SYMBOL_GPL(spi_async_locked);
3717 /*-------------------------------------------------------------------------*/
3719 /* Utility methods for SPI protocol drivers, layered on
3720 * top of the core. Some other utility methods are defined as
3724 static void spi_complete(void *arg)
3729 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3731 DECLARE_COMPLETION_ONSTACK(done);
3733 struct spi_controller *ctlr = spi->controller;
3734 unsigned long flags;
3736 status = __spi_validate(spi, message);
3740 message->complete = spi_complete;
3741 message->context = &done;
3744 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3745 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3747 /* If we're not using the legacy transfer method then we will
3748 * try to transfer in the calling context so special case.
3749 * This code would be less tricky if we could remove the
3750 * support for driver implemented message queues.
3752 if (ctlr->transfer == spi_queued_transfer) {
3753 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3755 trace_spi_message_submit(message);
3757 status = __spi_queued_transfer(spi, message, false);
3759 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3761 status = spi_async_locked(spi, message);
3765 /* Push out the messages in the calling context if we
3768 if (ctlr->transfer == spi_queued_transfer) {
3769 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3770 spi_sync_immediate);
3771 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3772 spi_sync_immediate);
3773 __spi_pump_messages(ctlr, false);
3776 wait_for_completion(&done);
3777 status = message->status;
3779 message->context = NULL;
3784 * spi_sync - blocking/synchronous SPI data transfers
3785 * @spi: device with which data will be exchanged
3786 * @message: describes the data transfers
3787 * Context: can sleep
3789 * This call may only be used from a context that may sleep. The sleep
3790 * is non-interruptible, and has no timeout. Low-overhead controller
3791 * drivers may DMA directly into and out of the message buffers.
3793 * Note that the SPI device's chip select is active during the message,
3794 * and then is normally disabled between messages. Drivers for some
3795 * frequently-used devices may want to minimize costs of selecting a chip,
3796 * by leaving it selected in anticipation that the next message will go
3797 * to the same chip. (That may increase power usage.)
3799 * Also, the caller is guaranteeing that the memory associated with the
3800 * message will not be freed before this call returns.
3802 * Return: zero on success, else a negative error code.
3804 int spi_sync(struct spi_device *spi, struct spi_message *message)
3808 mutex_lock(&spi->controller->bus_lock_mutex);
3809 ret = __spi_sync(spi, message);
3810 mutex_unlock(&spi->controller->bus_lock_mutex);
3814 EXPORT_SYMBOL_GPL(spi_sync);
3817 * spi_sync_locked - version of spi_sync with exclusive bus usage
3818 * @spi: device with which data will be exchanged
3819 * @message: describes the data transfers
3820 * Context: can sleep
3822 * This call may only be used from a context that may sleep. The sleep
3823 * is non-interruptible, and has no timeout. Low-overhead controller
3824 * drivers may DMA directly into and out of the message buffers.
3826 * This call should be used by drivers that require exclusive access to the
3827 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3828 * be released by a spi_bus_unlock call when the exclusive access is over.
3830 * Return: zero on success, else a negative error code.
3832 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3834 return __spi_sync(spi, message);
3836 EXPORT_SYMBOL_GPL(spi_sync_locked);
3839 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3840 * @ctlr: SPI bus master that should be locked for exclusive bus access
3841 * Context: can sleep
3843 * This call may only be used from a context that may sleep. The sleep
3844 * is non-interruptible, and has no timeout.
3846 * This call should be used by drivers that require exclusive access to the
3847 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3848 * exclusive access is over. Data transfer must be done by spi_sync_locked
3849 * and spi_async_locked calls when the SPI bus lock is held.
3851 * Return: always zero.
3853 int spi_bus_lock(struct spi_controller *ctlr)
3855 unsigned long flags;
3857 mutex_lock(&ctlr->bus_lock_mutex);
3859 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3860 ctlr->bus_lock_flag = 1;
3861 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3863 /* mutex remains locked until spi_bus_unlock is called */
3867 EXPORT_SYMBOL_GPL(spi_bus_lock);
3870 * spi_bus_unlock - release the lock for exclusive SPI bus usage
3871 * @ctlr: SPI bus master that was locked for exclusive bus access
3872 * Context: can sleep
3874 * This call may only be used from a context that may sleep. The sleep
3875 * is non-interruptible, and has no timeout.
3877 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3880 * Return: always zero.
3882 int spi_bus_unlock(struct spi_controller *ctlr)
3884 ctlr->bus_lock_flag = 0;
3886 mutex_unlock(&ctlr->bus_lock_mutex);
3890 EXPORT_SYMBOL_GPL(spi_bus_unlock);
3892 /* portable code must never pass more than 32 bytes */
3893 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3898 * spi_write_then_read - SPI synchronous write followed by read
3899 * @spi: device with which data will be exchanged
3900 * @txbuf: data to be written (need not be dma-safe)
3901 * @n_tx: size of txbuf, in bytes
3902 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3903 * @n_rx: size of rxbuf, in bytes
3904 * Context: can sleep
3906 * This performs a half duplex MicroWire style transaction with the
3907 * device, sending txbuf and then reading rxbuf. The return value
3908 * is zero for success, else a negative errno status code.
3909 * This call may only be used from a context that may sleep.
3911 * Parameters to this routine are always copied using a small buffer.
3912 * Performance-sensitive or bulk transfer code should instead use
3913 * spi_{async,sync}() calls with dma-safe buffers.
3915 * Return: zero on success, else a negative error code.
3917 int spi_write_then_read(struct spi_device *spi,
3918 const void *txbuf, unsigned n_tx,
3919 void *rxbuf, unsigned n_rx)
3921 static DEFINE_MUTEX(lock);
3924 struct spi_message message;
3925 struct spi_transfer x[2];
3928 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3929 * copying here, (as a pure convenience thing), but we can
3930 * keep heap costs out of the hot path unless someone else is
3931 * using the pre-allocated buffer or the transfer is too large.
3933 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
3934 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3935 GFP_KERNEL | GFP_DMA);
3942 spi_message_init(&message);
3943 memset(x, 0, sizeof(x));
3946 spi_message_add_tail(&x[0], &message);
3950 spi_message_add_tail(&x[1], &message);
3953 memcpy(local_buf, txbuf, n_tx);
3954 x[0].tx_buf = local_buf;
3955 x[1].rx_buf = local_buf + n_tx;
3958 status = spi_sync(spi, &message);
3960 memcpy(rxbuf, x[1].rx_buf, n_rx);
3962 if (x[0].tx_buf == buf)
3963 mutex_unlock(&lock);
3969 EXPORT_SYMBOL_GPL(spi_write_then_read);
3971 /*-------------------------------------------------------------------------*/
3973 #if IS_ENABLED(CONFIG_OF)
3974 /* must call put_device() when done with returned spi_device device */
3975 struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3977 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
3979 return dev ? to_spi_device(dev) : NULL;
3981 EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
3982 #endif /* IS_ENABLED(CONFIG_OF) */
3984 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
3985 /* the spi controllers are not using spi_bus, so we find it with another way */
3986 static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
3990 dev = class_find_device_by_of_node(&spi_master_class, node);
3991 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3992 dev = class_find_device_by_of_node(&spi_slave_class, node);
3996 /* reference got in class_find_device */
3997 return container_of(dev, struct spi_controller, dev);
4000 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
4003 struct of_reconfig_data *rd = arg;
4004 struct spi_controller *ctlr;
4005 struct spi_device *spi;
4007 switch (of_reconfig_get_state_change(action, arg)) {
4008 case OF_RECONFIG_CHANGE_ADD:
4009 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
4011 return NOTIFY_OK; /* not for us */
4013 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
4014 put_device(&ctlr->dev);
4018 spi = of_register_spi_device(ctlr, rd->dn);
4019 put_device(&ctlr->dev);
4022 pr_err("%s: failed to create for '%pOF'\n",
4024 of_node_clear_flag(rd->dn, OF_POPULATED);
4025 return notifier_from_errno(PTR_ERR(spi));
4029 case OF_RECONFIG_CHANGE_REMOVE:
4030 /* already depopulated? */
4031 if (!of_node_check_flag(rd->dn, OF_POPULATED))
4034 /* find our device by node */
4035 spi = of_find_spi_device_by_node(rd->dn);
4037 return NOTIFY_OK; /* no? not meant for us */
4039 /* unregister takes one ref away */
4040 spi_unregister_device(spi);
4042 /* and put the reference of the find */
4043 put_device(&spi->dev);
4050 static struct notifier_block spi_of_notifier = {
4051 .notifier_call = of_spi_notify,
4053 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4054 extern struct notifier_block spi_of_notifier;
4055 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4057 #if IS_ENABLED(CONFIG_ACPI)
4058 static int spi_acpi_controller_match(struct device *dev, const void *data)
4060 return ACPI_COMPANION(dev->parent) == data;
4063 static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4067 dev = class_find_device(&spi_master_class, NULL, adev,
4068 spi_acpi_controller_match);
4069 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4070 dev = class_find_device(&spi_slave_class, NULL, adev,
4071 spi_acpi_controller_match);
4075 return container_of(dev, struct spi_controller, dev);
4078 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4082 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4083 return to_spi_device(dev);
4086 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4089 struct acpi_device *adev = arg;
4090 struct spi_controller *ctlr;
4091 struct spi_device *spi;
4094 case ACPI_RECONFIG_DEVICE_ADD:
4095 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
4099 acpi_register_spi_device(ctlr, adev);
4100 put_device(&ctlr->dev);
4102 case ACPI_RECONFIG_DEVICE_REMOVE:
4103 if (!acpi_device_enumerated(adev))
4106 spi = acpi_spi_find_device_by_adev(adev);
4110 spi_unregister_device(spi);
4111 put_device(&spi->dev);
4118 static struct notifier_block spi_acpi_notifier = {
4119 .notifier_call = acpi_spi_notify,
4122 extern struct notifier_block spi_acpi_notifier;
4125 static int __init spi_init(void)
4129 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4135 status = bus_register(&spi_bus_type);
4139 status = class_register(&spi_master_class);
4143 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4144 status = class_register(&spi_slave_class);
4149 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4150 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4151 if (IS_ENABLED(CONFIG_ACPI))
4152 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4157 class_unregister(&spi_master_class);
4159 bus_unregister(&spi_bus_type);
4167 /* board_info is normally registered in arch_initcall(),
4168 * but even essential drivers wait till later
4170 * REVISIT only boardinfo really needs static linking. the rest (device and
4171 * driver registration) _could_ be dynamically linked (modular) ... costs
4172 * include needing to have boardinfo data structures be much more public.
4174 postcore_initcall(spi_init);