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 * spi_alloc_device - Allocate a new SPI device
480 * @ctlr: Controller to which device is connected
483 * Allows a driver to allocate and initialize a spi_device without
484 * registering it immediately. This allows a driver to directly
485 * fill the spi_device with device parameters before calling
486 * spi_add_device() on it.
488 * Caller is responsible to call spi_add_device() on the returned
489 * spi_device structure to add it to the SPI controller. If the caller
490 * needs to discard the spi_device without adding it, then it should
491 * call spi_dev_put() on it.
493 * Return: a pointer to the new device, or NULL.
495 struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
497 struct spi_device *spi;
499 if (!spi_controller_get(ctlr))
502 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
504 spi_controller_put(ctlr);
508 spi->master = spi->controller = ctlr;
509 spi->dev.parent = &ctlr->dev;
510 spi->dev.bus = &spi_bus_type;
511 spi->dev.release = spidev_release;
512 spi->cs_gpio = -ENOENT;
513 spi->mode = ctlr->buswidth_override_bits;
515 spin_lock_init(&spi->statistics.lock);
517 device_initialize(&spi->dev);
520 EXPORT_SYMBOL_GPL(spi_alloc_device);
522 static void spi_dev_set_name(struct spi_device *spi)
524 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
527 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
531 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
535 static int spi_dev_check(struct device *dev, void *data)
537 struct spi_device *spi = to_spi_device(dev);
538 struct spi_device *new_spi = data;
540 if (spi->controller == new_spi->controller &&
541 spi->chip_select == new_spi->chip_select)
547 * spi_add_device - Add spi_device allocated with spi_alloc_device
548 * @spi: spi_device to register
550 * Companion function to spi_alloc_device. Devices allocated with
551 * spi_alloc_device can be added onto the spi bus with this function.
553 * Return: 0 on success; negative errno on failure
555 int spi_add_device(struct spi_device *spi)
557 static DEFINE_MUTEX(spi_add_lock);
558 struct spi_controller *ctlr = spi->controller;
559 struct device *dev = ctlr->dev.parent;
562 /* Chipselects are numbered 0..max; validate. */
563 if (spi->chip_select >= ctlr->num_chipselect) {
564 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
565 ctlr->num_chipselect);
569 /* Set the bus ID string */
570 spi_dev_set_name(spi);
572 /* We need to make sure there's no other device with this
573 * chipselect **BEFORE** we call setup(), else we'll trash
574 * its configuration. Lock against concurrent add() calls.
576 mutex_lock(&spi_add_lock);
578 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
580 dev_err(dev, "chipselect %d already in use\n",
585 /* Descriptors take precedence */
587 spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
588 else if (ctlr->cs_gpios)
589 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
591 /* Drivers may modify this initial i/o setup, but will
592 * normally rely on the device being setup. Devices
593 * using SPI_CS_HIGH can't coexist well otherwise...
595 status = spi_setup(spi);
597 dev_err(dev, "can't setup %s, status %d\n",
598 dev_name(&spi->dev), status);
602 /* Device may be bound to an active driver when this returns */
603 status = device_add(&spi->dev);
605 dev_err(dev, "can't add %s, status %d\n",
606 dev_name(&spi->dev), status);
608 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
611 mutex_unlock(&spi_add_lock);
614 EXPORT_SYMBOL_GPL(spi_add_device);
617 * spi_new_device - instantiate one new SPI device
618 * @ctlr: Controller to which device is connected
619 * @chip: Describes the SPI device
622 * On typical mainboards, this is purely internal; and it's not needed
623 * after board init creates the hard-wired devices. Some development
624 * platforms may not be able to use spi_register_board_info though, and
625 * this is exported so that for example a USB or parport based adapter
626 * driver could add devices (which it would learn about out-of-band).
628 * Return: the new device, or NULL.
630 struct spi_device *spi_new_device(struct spi_controller *ctlr,
631 struct spi_board_info *chip)
633 struct spi_device *proxy;
636 /* NOTE: caller did any chip->bus_num checks necessary.
638 * Also, unless we change the return value convention to use
639 * error-or-pointer (not NULL-or-pointer), troubleshootability
640 * suggests syslogged diagnostics are best here (ugh).
643 proxy = spi_alloc_device(ctlr);
647 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
649 proxy->chip_select = chip->chip_select;
650 proxy->max_speed_hz = chip->max_speed_hz;
651 proxy->mode = chip->mode;
652 proxy->irq = chip->irq;
653 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
654 proxy->dev.platform_data = (void *) chip->platform_data;
655 proxy->controller_data = chip->controller_data;
656 proxy->controller_state = NULL;
658 if (chip->properties) {
659 status = device_add_properties(&proxy->dev, chip->properties);
662 "failed to add properties to '%s': %d\n",
663 chip->modalias, status);
668 status = spi_add_device(proxy);
670 goto err_remove_props;
675 if (chip->properties)
676 device_remove_properties(&proxy->dev);
681 EXPORT_SYMBOL_GPL(spi_new_device);
684 * spi_unregister_device - unregister a single SPI device
685 * @spi: spi_device to unregister
687 * Start making the passed SPI device vanish. Normally this would be handled
688 * by spi_unregister_controller().
690 void spi_unregister_device(struct spi_device *spi)
695 if (spi->dev.of_node) {
696 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
697 of_node_put(spi->dev.of_node);
699 if (ACPI_COMPANION(&spi->dev))
700 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
701 device_unregister(&spi->dev);
703 EXPORT_SYMBOL_GPL(spi_unregister_device);
705 static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
706 struct spi_board_info *bi)
708 struct spi_device *dev;
710 if (ctlr->bus_num != bi->bus_num)
713 dev = spi_new_device(ctlr, bi);
715 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
720 * spi_register_board_info - register SPI devices for a given board
721 * @info: array of chip descriptors
722 * @n: how many descriptors are provided
725 * Board-specific early init code calls this (probably during arch_initcall)
726 * with segments of the SPI device table. Any device nodes are created later,
727 * after the relevant parent SPI controller (bus_num) is defined. We keep
728 * this table of devices forever, so that reloading a controller driver will
729 * not make Linux forget about these hard-wired devices.
731 * Other code can also call this, e.g. a particular add-on board might provide
732 * SPI devices through its expansion connector, so code initializing that board
733 * would naturally declare its SPI devices.
735 * The board info passed can safely be __initdata ... but be careful of
736 * any embedded pointers (platform_data, etc), they're copied as-is.
737 * Device properties are deep-copied though.
739 * Return: zero on success, else a negative error code.
741 int spi_register_board_info(struct spi_board_info const *info, unsigned n)
743 struct boardinfo *bi;
749 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
753 for (i = 0; i < n; i++, bi++, info++) {
754 struct spi_controller *ctlr;
756 memcpy(&bi->board_info, info, sizeof(*info));
757 if (info->properties) {
758 bi->board_info.properties =
759 property_entries_dup(info->properties);
760 if (IS_ERR(bi->board_info.properties))
761 return PTR_ERR(bi->board_info.properties);
764 mutex_lock(&board_lock);
765 list_add_tail(&bi->list, &board_list);
766 list_for_each_entry(ctlr, &spi_controller_list, list)
767 spi_match_controller_to_boardinfo(ctlr,
769 mutex_unlock(&board_lock);
775 /*-------------------------------------------------------------------------*/
777 static void spi_set_cs(struct spi_device *spi, bool enable)
779 bool enable1 = enable;
782 * Avoid calling into the driver (or doing delays) if the chip select
783 * isn't actually changing from the last time this was called.
785 if ((spi->controller->last_cs_enable == enable) &&
786 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
789 spi->controller->last_cs_enable = enable;
790 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
792 if (!spi->controller->set_cs_timing) {
794 spi_delay_exec(&spi->controller->cs_setup, NULL);
796 spi_delay_exec(&spi->controller->cs_hold, NULL);
799 if (spi->mode & SPI_CS_HIGH)
802 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
804 * Honour the SPI_NO_CS flag and invert the enable line, as
805 * active low is default for SPI. Execution paths that handle
806 * polarity inversion in gpiolib (such as device tree) will
807 * enforce active high using the SPI_CS_HIGH resulting in a
808 * double inversion through the code above.
810 if (!(spi->mode & SPI_NO_CS)) {
812 gpiod_set_value_cansleep(spi->cs_gpiod,
815 gpio_set_value_cansleep(spi->cs_gpio, !enable);
817 /* Some SPI masters need both GPIO CS & slave_select */
818 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
819 spi->controller->set_cs)
820 spi->controller->set_cs(spi, !enable);
821 } else if (spi->controller->set_cs) {
822 spi->controller->set_cs(spi, !enable);
825 if (!spi->controller->set_cs_timing) {
827 spi_delay_exec(&spi->controller->cs_inactive, NULL);
831 #ifdef CONFIG_HAS_DMA
832 int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
833 struct sg_table *sgt, void *buf, size_t len,
834 enum dma_data_direction dir)
836 const bool vmalloced_buf = is_vmalloc_addr(buf);
837 unsigned int max_seg_size = dma_get_max_seg_size(dev);
838 #ifdef CONFIG_HIGHMEM
839 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
840 (unsigned long)buf < (PKMAP_BASE +
841 (LAST_PKMAP * PAGE_SIZE)));
843 const bool kmap_buf = false;
847 struct page *vm_page;
848 struct scatterlist *sg;
853 if (vmalloced_buf || kmap_buf) {
854 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
855 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
856 } else if (virt_addr_valid(buf)) {
857 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
858 sgs = DIV_ROUND_UP(len, desc_len);
863 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
868 for (i = 0; i < sgs; i++) {
870 if (vmalloced_buf || kmap_buf) {
872 * Next scatterlist entry size is the minimum between
873 * the desc_len and the remaining buffer length that
876 min = min_t(size_t, desc_len,
878 PAGE_SIZE - offset_in_page(buf)));
880 vm_page = vmalloc_to_page(buf);
882 vm_page = kmap_to_page(buf);
887 sg_set_page(sg, vm_page,
888 min, offset_in_page(buf));
890 min = min_t(size_t, len, desc_len);
892 sg_set_buf(sg, sg_buf, min);
900 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
913 void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
914 struct sg_table *sgt, enum dma_data_direction dir)
916 if (sgt->orig_nents) {
917 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
922 static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
924 struct device *tx_dev, *rx_dev;
925 struct spi_transfer *xfer;
932 tx_dev = ctlr->dma_tx->device->dev;
934 tx_dev = ctlr->dev.parent;
937 rx_dev = ctlr->dma_rx->device->dev;
939 rx_dev = ctlr->dev.parent;
941 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
942 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
945 if (xfer->tx_buf != NULL) {
946 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
947 (void *)xfer->tx_buf, xfer->len,
953 if (xfer->rx_buf != NULL) {
954 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
955 xfer->rx_buf, xfer->len,
958 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
965 ctlr->cur_msg_mapped = true;
970 static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
972 struct spi_transfer *xfer;
973 struct device *tx_dev, *rx_dev;
975 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
979 tx_dev = ctlr->dma_tx->device->dev;
981 tx_dev = ctlr->dev.parent;
984 rx_dev = ctlr->dma_rx->device->dev;
986 rx_dev = ctlr->dev.parent;
988 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
989 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
992 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
993 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
996 ctlr->cur_msg_mapped = false;
1000 #else /* !CONFIG_HAS_DMA */
1001 static inline int __spi_map_msg(struct spi_controller *ctlr,
1002 struct spi_message *msg)
1007 static inline int __spi_unmap_msg(struct spi_controller *ctlr,
1008 struct spi_message *msg)
1012 #endif /* !CONFIG_HAS_DMA */
1014 static inline int spi_unmap_msg(struct spi_controller *ctlr,
1015 struct spi_message *msg)
1017 struct spi_transfer *xfer;
1019 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1021 * Restore the original value of tx_buf or rx_buf if they are
1024 if (xfer->tx_buf == ctlr->dummy_tx)
1025 xfer->tx_buf = NULL;
1026 if (xfer->rx_buf == ctlr->dummy_rx)
1027 xfer->rx_buf = NULL;
1030 return __spi_unmap_msg(ctlr, msg);
1033 static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1035 struct spi_transfer *xfer;
1037 unsigned int max_tx, max_rx;
1039 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1040 && !(msg->spi->mode & SPI_3WIRE)) {
1044 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1045 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1047 max_tx = max(xfer->len, max_tx);
1048 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1050 max_rx = max(xfer->len, max_rx);
1054 tmp = krealloc(ctlr->dummy_tx, max_tx,
1055 GFP_KERNEL | GFP_DMA);
1058 ctlr->dummy_tx = tmp;
1059 memset(tmp, 0, max_tx);
1063 tmp = krealloc(ctlr->dummy_rx, max_rx,
1064 GFP_KERNEL | GFP_DMA);
1067 ctlr->dummy_rx = tmp;
1070 if (max_tx || max_rx) {
1071 list_for_each_entry(xfer, &msg->transfers,
1076 xfer->tx_buf = ctlr->dummy_tx;
1078 xfer->rx_buf = ctlr->dummy_rx;
1083 return __spi_map_msg(ctlr, msg);
1086 static int spi_transfer_wait(struct spi_controller *ctlr,
1087 struct spi_message *msg,
1088 struct spi_transfer *xfer)
1090 struct spi_statistics *statm = &ctlr->statistics;
1091 struct spi_statistics *stats = &msg->spi->statistics;
1092 unsigned long long ms;
1094 if (spi_controller_is_slave(ctlr)) {
1095 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1096 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1100 ms = 8LL * 1000LL * xfer->len;
1101 do_div(ms, xfer->speed_hz);
1102 ms += ms + 200; /* some tolerance */
1107 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1108 msecs_to_jiffies(ms));
1111 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1112 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1113 dev_err(&msg->spi->dev,
1114 "SPI transfer timed out\n");
1122 static void _spi_transfer_delay_ns(u32 ns)
1129 u32 us = DIV_ROUND_UP(ns, 1000);
1134 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1138 int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1140 u32 delay = _delay->value;
1141 u32 unit = _delay->unit;
1148 case SPI_DELAY_UNIT_USECS:
1151 case SPI_DELAY_UNIT_NSECS: /* nothing to do here */
1153 case SPI_DELAY_UNIT_SCK:
1154 /* clock cycles need to be obtained from spi_transfer */
1157 /* if there is no effective speed know, then approximate
1158 * by underestimating with half the requested hz
1160 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1163 delay *= DIV_ROUND_UP(1000000000, hz);
1171 EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1173 int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1182 delay = spi_delay_to_ns(_delay, xfer);
1186 _spi_transfer_delay_ns(delay);
1190 EXPORT_SYMBOL_GPL(spi_delay_exec);
1192 static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1193 struct spi_transfer *xfer)
1195 u32 delay = xfer->cs_change_delay.value;
1196 u32 unit = xfer->cs_change_delay.unit;
1199 /* return early on "fast" mode - for everything but USECS */
1201 if (unit == SPI_DELAY_UNIT_USECS)
1202 _spi_transfer_delay_ns(10000);
1206 ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1208 dev_err_once(&msg->spi->dev,
1209 "Use of unsupported delay unit %i, using default of 10us\n",
1211 _spi_transfer_delay_ns(10000);
1216 * spi_transfer_one_message - Default implementation of transfer_one_message()
1218 * This is a standard implementation of transfer_one_message() for
1219 * drivers which implement a transfer_one() operation. It provides
1220 * standard handling of delays and chip select management.
1222 static int spi_transfer_one_message(struct spi_controller *ctlr,
1223 struct spi_message *msg)
1225 struct spi_transfer *xfer;
1226 bool keep_cs = false;
1228 struct spi_statistics *statm = &ctlr->statistics;
1229 struct spi_statistics *stats = &msg->spi->statistics;
1231 spi_set_cs(msg->spi, true);
1233 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1234 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1236 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1237 trace_spi_transfer_start(msg, xfer);
1239 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1240 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1242 if (!ctlr->ptp_sts_supported) {
1243 xfer->ptp_sts_word_pre = 0;
1244 ptp_read_system_prets(xfer->ptp_sts);
1247 if (xfer->tx_buf || xfer->rx_buf) {
1248 reinit_completion(&ctlr->xfer_completion);
1251 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1253 if (ctlr->cur_msg_mapped &&
1254 (xfer->error & SPI_TRANS_FAIL_NO_START)) {
1255 __spi_unmap_msg(ctlr, msg);
1256 ctlr->fallback = true;
1257 xfer->error &= ~SPI_TRANS_FAIL_NO_START;
1261 SPI_STATISTICS_INCREMENT_FIELD(statm,
1263 SPI_STATISTICS_INCREMENT_FIELD(stats,
1265 dev_err(&msg->spi->dev,
1266 "SPI transfer failed: %d\n", ret);
1271 ret = spi_transfer_wait(ctlr, msg, xfer);
1277 dev_err(&msg->spi->dev,
1278 "Bufferless transfer has length %u\n",
1282 if (!ctlr->ptp_sts_supported) {
1283 ptp_read_system_postts(xfer->ptp_sts);
1284 xfer->ptp_sts_word_post = xfer->len;
1287 trace_spi_transfer_stop(msg, xfer);
1289 if (msg->status != -EINPROGRESS)
1292 spi_transfer_delay_exec(xfer);
1294 if (xfer->cs_change) {
1295 if (list_is_last(&xfer->transfer_list,
1299 spi_set_cs(msg->spi, false);
1300 _spi_transfer_cs_change_delay(msg, xfer);
1301 spi_set_cs(msg->spi, true);
1305 msg->actual_length += xfer->len;
1309 if (ret != 0 || !keep_cs)
1310 spi_set_cs(msg->spi, false);
1312 if (msg->status == -EINPROGRESS)
1315 if (msg->status && ctlr->handle_err)
1316 ctlr->handle_err(ctlr, msg);
1318 spi_res_release(ctlr, msg);
1320 spi_finalize_current_message(ctlr);
1326 * spi_finalize_current_transfer - report completion of a transfer
1327 * @ctlr: the controller reporting completion
1329 * Called by SPI drivers using the core transfer_one_message()
1330 * implementation to notify it that the current interrupt driven
1331 * transfer has finished and the next one may be scheduled.
1333 void spi_finalize_current_transfer(struct spi_controller *ctlr)
1335 complete(&ctlr->xfer_completion);
1337 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1339 static void spi_idle_runtime_pm(struct spi_controller *ctlr)
1341 if (ctlr->auto_runtime_pm) {
1342 pm_runtime_mark_last_busy(ctlr->dev.parent);
1343 pm_runtime_put_autosuspend(ctlr->dev.parent);
1348 * __spi_pump_messages - function which processes spi message queue
1349 * @ctlr: controller to process queue for
1350 * @in_kthread: true if we are in the context of the message pump thread
1352 * This function checks if there is any spi message in the queue that
1353 * needs processing and if so call out to the driver to initialize hardware
1354 * and transfer each message.
1356 * Note that it is called both from the kthread itself and also from
1357 * inside spi_sync(); the queue extraction handling at the top of the
1358 * function should deal with this safely.
1360 static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1362 struct spi_transfer *xfer;
1363 struct spi_message *msg;
1364 bool was_busy = false;
1365 unsigned long flags;
1369 spin_lock_irqsave(&ctlr->queue_lock, flags);
1371 /* Make sure we are not already running a message */
1372 if (ctlr->cur_msg) {
1373 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1377 /* If another context is idling the device then defer */
1379 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1380 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1384 /* Check if the queue is idle */
1385 if (list_empty(&ctlr->queue) || !ctlr->running) {
1387 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1391 /* Defer any non-atomic teardown to the thread */
1393 if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
1394 !ctlr->unprepare_transfer_hardware) {
1395 spi_idle_runtime_pm(ctlr);
1397 trace_spi_controller_idle(ctlr);
1399 kthread_queue_work(ctlr->kworker,
1400 &ctlr->pump_messages);
1402 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1407 ctlr->idling = true;
1408 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1410 kfree(ctlr->dummy_rx);
1411 ctlr->dummy_rx = NULL;
1412 kfree(ctlr->dummy_tx);
1413 ctlr->dummy_tx = NULL;
1414 if (ctlr->unprepare_transfer_hardware &&
1415 ctlr->unprepare_transfer_hardware(ctlr))
1417 "failed to unprepare transfer hardware\n");
1418 spi_idle_runtime_pm(ctlr);
1419 trace_spi_controller_idle(ctlr);
1421 spin_lock_irqsave(&ctlr->queue_lock, flags);
1422 ctlr->idling = false;
1423 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1427 /* Extract head of queue */
1428 msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1429 ctlr->cur_msg = msg;
1431 list_del_init(&msg->queue);
1436 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1438 mutex_lock(&ctlr->io_mutex);
1440 if (!was_busy && ctlr->auto_runtime_pm) {
1441 ret = pm_runtime_get_sync(ctlr->dev.parent);
1443 pm_runtime_put_noidle(ctlr->dev.parent);
1444 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1446 mutex_unlock(&ctlr->io_mutex);
1452 trace_spi_controller_busy(ctlr);
1454 if (!was_busy && ctlr->prepare_transfer_hardware) {
1455 ret = ctlr->prepare_transfer_hardware(ctlr);
1458 "failed to prepare transfer hardware: %d\n",
1461 if (ctlr->auto_runtime_pm)
1462 pm_runtime_put(ctlr->dev.parent);
1465 spi_finalize_current_message(ctlr);
1467 mutex_unlock(&ctlr->io_mutex);
1472 trace_spi_message_start(msg);
1474 if (ctlr->prepare_message) {
1475 ret = ctlr->prepare_message(ctlr, msg);
1477 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1480 spi_finalize_current_message(ctlr);
1483 ctlr->cur_msg_prepared = true;
1486 ret = spi_map_msg(ctlr, msg);
1489 spi_finalize_current_message(ctlr);
1493 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1494 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1495 xfer->ptp_sts_word_pre = 0;
1496 ptp_read_system_prets(xfer->ptp_sts);
1500 ret = ctlr->transfer_one_message(ctlr, msg);
1503 "failed to transfer one message from queue\n");
1508 mutex_unlock(&ctlr->io_mutex);
1510 /* Prod the scheduler in case transfer_one() was busy waiting */
1516 * spi_pump_messages - kthread work function which processes spi message queue
1517 * @work: pointer to kthread work struct contained in the controller struct
1519 static void spi_pump_messages(struct kthread_work *work)
1521 struct spi_controller *ctlr =
1522 container_of(work, struct spi_controller, pump_messages);
1524 __spi_pump_messages(ctlr, true);
1528 * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
1529 * TX timestamp for the requested byte from the SPI
1530 * transfer. The frequency with which this function
1531 * must be called (once per word, once for the whole
1532 * transfer, once per batch of words etc) is arbitrary
1533 * as long as the @tx buffer offset is greater than or
1534 * equal to the requested byte at the time of the
1535 * call. The timestamp is only taken once, at the
1536 * first such call. It is assumed that the driver
1537 * advances its @tx buffer pointer monotonically.
1538 * @ctlr: Pointer to the spi_controller structure of the driver
1539 * @xfer: Pointer to the transfer being timestamped
1540 * @progress: How many words (not bytes) have been transferred so far
1541 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1542 * transfer, for less jitter in time measurement. Only compatible
1543 * with PIO drivers. If true, must follow up with
1544 * spi_take_timestamp_post or otherwise system will crash.
1545 * WARNING: for fully predictable results, the CPU frequency must
1546 * also be under control (governor).
1548 void spi_take_timestamp_pre(struct spi_controller *ctlr,
1549 struct spi_transfer *xfer,
1550 size_t progress, bool irqs_off)
1555 if (xfer->timestamped)
1558 if (progress > xfer->ptp_sts_word_pre)
1561 /* Capture the resolution of the timestamp */
1562 xfer->ptp_sts_word_pre = progress;
1565 local_irq_save(ctlr->irq_flags);
1569 ptp_read_system_prets(xfer->ptp_sts);
1571 EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
1574 * spi_take_timestamp_post - helper for drivers to collect the end of the
1575 * TX timestamp for the requested byte from the SPI
1576 * transfer. Can be called with an arbitrary
1577 * frequency: only the first call where @tx exceeds
1578 * or is equal to the requested word will be
1580 * @ctlr: Pointer to the spi_controller structure of the driver
1581 * @xfer: Pointer to the transfer being timestamped
1582 * @progress: How many words (not bytes) have been transferred so far
1583 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1585 void spi_take_timestamp_post(struct spi_controller *ctlr,
1586 struct spi_transfer *xfer,
1587 size_t progress, bool irqs_off)
1592 if (xfer->timestamped)
1595 if (progress < xfer->ptp_sts_word_post)
1598 ptp_read_system_postts(xfer->ptp_sts);
1601 local_irq_restore(ctlr->irq_flags);
1605 /* Capture the resolution of the timestamp */
1606 xfer->ptp_sts_word_post = progress;
1608 xfer->timestamped = true;
1610 EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
1613 * spi_set_thread_rt - set the controller to pump at realtime priority
1614 * @ctlr: controller to boost priority of
1616 * This can be called because the controller requested realtime priority
1617 * (by setting the ->rt value before calling spi_register_controller()) or
1618 * because a device on the bus said that its transfers needed realtime
1621 * NOTE: at the moment if any device on a bus says it needs realtime then
1622 * the thread will be at realtime priority for all transfers on that
1623 * controller. If this eventually becomes a problem we may see if we can
1624 * find a way to boost the priority only temporarily during relevant
1627 static void spi_set_thread_rt(struct spi_controller *ctlr)
1629 dev_info(&ctlr->dev,
1630 "will run message pump with realtime priority\n");
1631 sched_set_fifo(ctlr->kworker->task);
1634 static int spi_init_queue(struct spi_controller *ctlr)
1636 ctlr->running = false;
1639 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
1640 if (IS_ERR(ctlr->kworker)) {
1641 dev_err(&ctlr->dev, "failed to create message pump kworker\n");
1642 return PTR_ERR(ctlr->kworker);
1645 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1648 * Controller config will indicate if this controller should run the
1649 * message pump with high (realtime) priority to reduce the transfer
1650 * latency on the bus by minimising the delay between a transfer
1651 * request and the scheduling of the message pump thread. Without this
1652 * setting the message pump thread will remain at default priority.
1655 spi_set_thread_rt(ctlr);
1661 * spi_get_next_queued_message() - called by driver to check for queued
1663 * @ctlr: the controller to check for queued messages
1665 * If there are more messages in the queue, the next message is returned from
1668 * Return: the next message in the queue, else NULL if the queue is empty.
1670 struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1672 struct spi_message *next;
1673 unsigned long flags;
1675 /* get a pointer to the next message, if any */
1676 spin_lock_irqsave(&ctlr->queue_lock, flags);
1677 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1679 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1683 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1686 * spi_finalize_current_message() - the current message is complete
1687 * @ctlr: the controller to return the message to
1689 * Called by the driver to notify the core that the message in the front of the
1690 * queue is complete and can be removed from the queue.
1692 void spi_finalize_current_message(struct spi_controller *ctlr)
1694 struct spi_transfer *xfer;
1695 struct spi_message *mesg;
1696 unsigned long flags;
1699 spin_lock_irqsave(&ctlr->queue_lock, flags);
1700 mesg = ctlr->cur_msg;
1701 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1703 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1704 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
1705 ptp_read_system_postts(xfer->ptp_sts);
1706 xfer->ptp_sts_word_post = xfer->len;
1710 if (unlikely(ctlr->ptp_sts_supported))
1711 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
1712 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
1714 spi_unmap_msg(ctlr, mesg);
1716 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1717 ret = ctlr->unprepare_message(ctlr, mesg);
1719 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1724 spin_lock_irqsave(&ctlr->queue_lock, flags);
1725 ctlr->cur_msg = NULL;
1726 ctlr->cur_msg_prepared = false;
1727 ctlr->fallback = false;
1728 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1729 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1731 trace_spi_message_done(mesg);
1735 mesg->complete(mesg->context);
1737 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1739 static int spi_start_queue(struct spi_controller *ctlr)
1741 unsigned long flags;
1743 spin_lock_irqsave(&ctlr->queue_lock, flags);
1745 if (ctlr->running || ctlr->busy) {
1746 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1750 ctlr->running = true;
1751 ctlr->cur_msg = NULL;
1752 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1754 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1759 static int spi_stop_queue(struct spi_controller *ctlr)
1761 unsigned long flags;
1762 unsigned limit = 500;
1765 spin_lock_irqsave(&ctlr->queue_lock, flags);
1768 * This is a bit lame, but is optimized for the common execution path.
1769 * A wait_queue on the ctlr->busy could be used, but then the common
1770 * execution path (pump_messages) would be required to call wake_up or
1771 * friends on every SPI message. Do this instead.
1773 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1774 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1775 usleep_range(10000, 11000);
1776 spin_lock_irqsave(&ctlr->queue_lock, flags);
1779 if (!list_empty(&ctlr->queue) || ctlr->busy)
1782 ctlr->running = false;
1784 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1787 dev_warn(&ctlr->dev, "could not stop message queue\n");
1793 static int spi_destroy_queue(struct spi_controller *ctlr)
1797 ret = spi_stop_queue(ctlr);
1800 * kthread_flush_worker will block until all work is done.
1801 * If the reason that stop_queue timed out is that the work will never
1802 * finish, then it does no good to call flush/stop thread, so
1806 dev_err(&ctlr->dev, "problem destroying queue\n");
1810 kthread_destroy_worker(ctlr->kworker);
1815 static int __spi_queued_transfer(struct spi_device *spi,
1816 struct spi_message *msg,
1819 struct spi_controller *ctlr = spi->controller;
1820 unsigned long flags;
1822 spin_lock_irqsave(&ctlr->queue_lock, flags);
1824 if (!ctlr->running) {
1825 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1828 msg->actual_length = 0;
1829 msg->status = -EINPROGRESS;
1831 list_add_tail(&msg->queue, &ctlr->queue);
1832 if (!ctlr->busy && need_pump)
1833 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1835 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1840 * spi_queued_transfer - transfer function for queued transfers
1841 * @spi: spi device which is requesting transfer
1842 * @msg: spi message which is to handled is queued to driver queue
1844 * Return: zero on success, else a negative error code.
1846 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1848 return __spi_queued_transfer(spi, msg, true);
1851 static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1855 ctlr->transfer = spi_queued_transfer;
1856 if (!ctlr->transfer_one_message)
1857 ctlr->transfer_one_message = spi_transfer_one_message;
1859 /* Initialize and start queue */
1860 ret = spi_init_queue(ctlr);
1862 dev_err(&ctlr->dev, "problem initializing queue\n");
1863 goto err_init_queue;
1865 ctlr->queued = true;
1866 ret = spi_start_queue(ctlr);
1868 dev_err(&ctlr->dev, "problem starting queue\n");
1869 goto err_start_queue;
1875 spi_destroy_queue(ctlr);
1881 * spi_flush_queue - Send all pending messages in the queue from the callers'
1883 * @ctlr: controller to process queue for
1885 * This should be used when one wants to ensure all pending messages have been
1886 * sent before doing something. Is used by the spi-mem code to make sure SPI
1887 * memory operations do not preempt regular SPI transfers that have been queued
1888 * before the spi-mem operation.
1890 void spi_flush_queue(struct spi_controller *ctlr)
1892 if (ctlr->transfer == spi_queued_transfer)
1893 __spi_pump_messages(ctlr, false);
1896 /*-------------------------------------------------------------------------*/
1898 #if defined(CONFIG_OF)
1899 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1900 struct device_node *nc)
1905 /* Mode (clock phase/polarity/etc.) */
1906 if (of_property_read_bool(nc, "spi-cpha"))
1907 spi->mode |= SPI_CPHA;
1908 if (of_property_read_bool(nc, "spi-cpol"))
1909 spi->mode |= SPI_CPOL;
1910 if (of_property_read_bool(nc, "spi-3wire"))
1911 spi->mode |= SPI_3WIRE;
1912 if (of_property_read_bool(nc, "spi-lsb-first"))
1913 spi->mode |= SPI_LSB_FIRST;
1914 if (of_property_read_bool(nc, "spi-cs-high"))
1915 spi->mode |= SPI_CS_HIGH;
1917 /* Device DUAL/QUAD mode */
1918 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1923 spi->mode |= SPI_TX_DUAL;
1926 spi->mode |= SPI_TX_QUAD;
1929 spi->mode |= SPI_TX_OCTAL;
1932 dev_warn(&ctlr->dev,
1933 "spi-tx-bus-width %d not supported\n",
1939 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1944 spi->mode |= SPI_RX_DUAL;
1947 spi->mode |= SPI_RX_QUAD;
1950 spi->mode |= SPI_RX_OCTAL;
1953 dev_warn(&ctlr->dev,
1954 "spi-rx-bus-width %d not supported\n",
1960 if (spi_controller_is_slave(ctlr)) {
1961 if (!of_node_name_eq(nc, "slave")) {
1962 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
1969 /* Device address */
1970 rc = of_property_read_u32(nc, "reg", &value);
1972 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
1976 spi->chip_select = value;
1979 * For descriptors associated with the device, polarity inversion is
1980 * handled in the gpiolib, so all gpio chip selects are "active high"
1981 * in the logical sense, the gpiolib will invert the line if need be.
1983 if ((ctlr->use_gpio_descriptors) && ctlr->cs_gpiods &&
1984 ctlr->cs_gpiods[spi->chip_select])
1985 spi->mode |= SPI_CS_HIGH;
1988 if (!of_property_read_u32(nc, "spi-max-frequency", &value))
1989 spi->max_speed_hz = value;
1994 static struct spi_device *
1995 of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
1997 struct spi_device *spi;
2000 /* Alloc an spi_device */
2001 spi = spi_alloc_device(ctlr);
2003 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
2008 /* Select device driver */
2009 rc = of_modalias_node(nc, spi->modalias,
2010 sizeof(spi->modalias));
2012 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
2016 rc = of_spi_parse_dt(ctlr, spi, nc);
2020 /* Store a pointer to the node in the device structure */
2022 spi->dev.of_node = nc;
2024 /* Register the new device */
2025 rc = spi_add_device(spi);
2027 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
2028 goto err_of_node_put;
2041 * of_register_spi_devices() - Register child devices onto the SPI bus
2042 * @ctlr: Pointer to spi_controller device
2044 * Registers an spi_device for each child node of controller node which
2045 * represents a valid SPI slave.
2047 static void of_register_spi_devices(struct spi_controller *ctlr)
2049 struct spi_device *spi;
2050 struct device_node *nc;
2052 if (!ctlr->dev.of_node)
2055 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2056 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2058 spi = of_register_spi_device(ctlr, nc);
2060 dev_warn(&ctlr->dev,
2061 "Failed to create SPI device for %pOF\n", nc);
2062 of_node_clear_flag(nc, OF_POPULATED);
2067 static void of_register_spi_devices(struct spi_controller *ctlr) { }
2071 struct acpi_spi_lookup {
2072 struct spi_controller *ctlr;
2080 static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2081 struct acpi_spi_lookup *lookup)
2083 const union acpi_object *obj;
2085 if (!x86_apple_machine)
2088 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2089 && obj->buffer.length >= 4)
2090 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2092 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2093 && obj->buffer.length == 8)
2094 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2096 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2097 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2098 lookup->mode |= SPI_LSB_FIRST;
2100 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2101 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2102 lookup->mode |= SPI_CPOL;
2104 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2105 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2106 lookup->mode |= SPI_CPHA;
2109 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2111 struct acpi_spi_lookup *lookup = data;
2112 struct spi_controller *ctlr = lookup->ctlr;
2114 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2115 struct acpi_resource_spi_serialbus *sb;
2116 acpi_handle parent_handle;
2119 sb = &ares->data.spi_serial_bus;
2120 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2122 status = acpi_get_handle(NULL,
2123 sb->resource_source.string_ptr,
2126 if (ACPI_FAILURE(status) ||
2127 ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
2131 * ACPI DeviceSelection numbering is handled by the
2132 * host controller driver in Windows and can vary
2133 * from driver to driver. In Linux we always expect
2134 * 0 .. max - 1 so we need to ask the driver to
2135 * translate between the two schemes.
2137 if (ctlr->fw_translate_cs) {
2138 int cs = ctlr->fw_translate_cs(ctlr,
2139 sb->device_selection);
2142 lookup->chip_select = cs;
2144 lookup->chip_select = sb->device_selection;
2147 lookup->max_speed_hz = sb->connection_speed;
2148 lookup->bits_per_word = sb->data_bit_length;
2150 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2151 lookup->mode |= SPI_CPHA;
2152 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2153 lookup->mode |= SPI_CPOL;
2154 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2155 lookup->mode |= SPI_CS_HIGH;
2157 } else if (lookup->irq < 0) {
2160 if (acpi_dev_resource_interrupt(ares, 0, &r))
2161 lookup->irq = r.start;
2164 /* Always tell the ACPI core to skip this resource */
2168 static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2169 struct acpi_device *adev)
2171 acpi_handle parent_handle = NULL;
2172 struct list_head resource_list;
2173 struct acpi_spi_lookup lookup = {};
2174 struct spi_device *spi;
2177 if (acpi_bus_get_status(adev) || !adev->status.present ||
2178 acpi_device_enumerated(adev))
2184 INIT_LIST_HEAD(&resource_list);
2185 ret = acpi_dev_get_resources(adev, &resource_list,
2186 acpi_spi_add_resource, &lookup);
2187 acpi_dev_free_resource_list(&resource_list);
2190 /* found SPI in _CRS but it points to another controller */
2193 if (!lookup.max_speed_hz &&
2194 !ACPI_FAILURE(acpi_get_parent(adev->handle, &parent_handle)) &&
2195 ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {
2196 /* Apple does not use _CRS but nested devices for SPI slaves */
2197 acpi_spi_parse_apple_properties(adev, &lookup);
2200 if (!lookup.max_speed_hz)
2203 spi = spi_alloc_device(ctlr);
2205 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
2206 dev_name(&adev->dev));
2207 return AE_NO_MEMORY;
2211 ACPI_COMPANION_SET(&spi->dev, adev);
2212 spi->max_speed_hz = lookup.max_speed_hz;
2213 spi->mode |= lookup.mode;
2214 spi->irq = lookup.irq;
2215 spi->bits_per_word = lookup.bits_per_word;
2216 spi->chip_select = lookup.chip_select;
2218 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2219 sizeof(spi->modalias));
2222 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
2224 acpi_device_set_enumerated(adev);
2226 adev->power.flags.ignore_parent = true;
2227 if (spi_add_device(spi)) {
2228 adev->power.flags.ignore_parent = false;
2229 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2230 dev_name(&adev->dev));
2237 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2238 void *data, void **return_value)
2240 struct spi_controller *ctlr = data;
2241 struct acpi_device *adev;
2243 if (acpi_bus_get_device(handle, &adev))
2246 return acpi_register_spi_device(ctlr, adev);
2249 #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2251 static void acpi_register_spi_devices(struct spi_controller *ctlr)
2256 handle = ACPI_HANDLE(ctlr->dev.parent);
2260 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2261 SPI_ACPI_ENUMERATE_MAX_DEPTH,
2262 acpi_spi_add_device, NULL, ctlr, NULL);
2263 if (ACPI_FAILURE(status))
2264 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2267 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2268 #endif /* CONFIG_ACPI */
2270 static void spi_controller_release(struct device *dev)
2272 struct spi_controller *ctlr;
2274 ctlr = container_of(dev, struct spi_controller, dev);
2278 static struct class spi_master_class = {
2279 .name = "spi_master",
2280 .owner = THIS_MODULE,
2281 .dev_release = spi_controller_release,
2282 .dev_groups = spi_master_groups,
2285 #ifdef CONFIG_SPI_SLAVE
2287 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2289 * @spi: device used for the current transfer
2291 int spi_slave_abort(struct spi_device *spi)
2293 struct spi_controller *ctlr = spi->controller;
2295 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
2296 return ctlr->slave_abort(ctlr);
2300 EXPORT_SYMBOL_GPL(spi_slave_abort);
2302 static int match_true(struct device *dev, void *data)
2307 static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2310 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2312 struct device *child;
2314 child = device_find_child(&ctlr->dev, NULL, match_true);
2315 return sprintf(buf, "%s\n",
2316 child ? to_spi_device(child)->modalias : NULL);
2319 static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
2320 const char *buf, size_t count)
2322 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2324 struct spi_device *spi;
2325 struct device *child;
2329 rc = sscanf(buf, "%31s", name);
2330 if (rc != 1 || !name[0])
2333 child = device_find_child(&ctlr->dev, NULL, match_true);
2335 /* Remove registered slave */
2336 device_unregister(child);
2340 if (strcmp(name, "(null)")) {
2341 /* Register new slave */
2342 spi = spi_alloc_device(ctlr);
2346 strlcpy(spi->modalias, name, sizeof(spi->modalias));
2348 rc = spi_add_device(spi);
2358 static DEVICE_ATTR_RW(slave);
2360 static struct attribute *spi_slave_attrs[] = {
2361 &dev_attr_slave.attr,
2365 static const struct attribute_group spi_slave_group = {
2366 .attrs = spi_slave_attrs,
2369 static const struct attribute_group *spi_slave_groups[] = {
2370 &spi_controller_statistics_group,
2375 static struct class spi_slave_class = {
2376 .name = "spi_slave",
2377 .owner = THIS_MODULE,
2378 .dev_release = spi_controller_release,
2379 .dev_groups = spi_slave_groups,
2382 extern struct class spi_slave_class; /* dummy */
2386 * __spi_alloc_controller - allocate an SPI master or slave controller
2387 * @dev: the controller, possibly using the platform_bus
2388 * @size: how much zeroed driver-private data to allocate; the pointer to this
2389 * memory is in the driver_data field of the returned device, accessible
2390 * with spi_controller_get_devdata(); the memory is cacheline aligned;
2391 * drivers granting DMA access to portions of their private data need to
2392 * round up @size using ALIGN(size, dma_get_cache_alignment()).
2393 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2394 * slave (true) controller
2395 * Context: can sleep
2397 * This call is used only by SPI controller drivers, which are the
2398 * only ones directly touching chip registers. It's how they allocate
2399 * an spi_controller structure, prior to calling spi_register_controller().
2401 * This must be called from context that can sleep.
2403 * The caller is responsible for assigning the bus number and initializing the
2404 * controller's methods before calling spi_register_controller(); and (after
2405 * errors adding the device) calling spi_controller_put() to prevent a memory
2408 * Return: the SPI controller structure on success, else NULL.
2410 struct spi_controller *__spi_alloc_controller(struct device *dev,
2411 unsigned int size, bool slave)
2413 struct spi_controller *ctlr;
2414 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
2419 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
2423 device_initialize(&ctlr->dev);
2425 ctlr->num_chipselect = 1;
2426 ctlr->slave = slave;
2427 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2428 ctlr->dev.class = &spi_slave_class;
2430 ctlr->dev.class = &spi_master_class;
2431 ctlr->dev.parent = dev;
2432 pm_suspend_ignore_children(&ctlr->dev, true);
2433 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
2437 EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2440 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2443 struct device_node *np = ctlr->dev.of_node;
2448 nb = of_gpio_named_count(np, "cs-gpios");
2449 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2451 /* Return error only for an incorrectly formed cs-gpios property */
2452 if (nb == 0 || nb == -ENOENT)
2457 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2459 ctlr->cs_gpios = cs;
2461 if (!ctlr->cs_gpios)
2464 for (i = 0; i < ctlr->num_chipselect; i++)
2467 for (i = 0; i < nb; i++)
2468 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2473 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2480 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2481 * @ctlr: The SPI master to grab GPIO descriptors for
2483 static int spi_get_gpio_descs(struct spi_controller *ctlr)
2486 struct gpio_desc **cs;
2487 struct device *dev = &ctlr->dev;
2488 unsigned long native_cs_mask = 0;
2489 unsigned int num_cs_gpios = 0;
2491 nb = gpiod_count(dev, "cs");
2492 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2494 /* No GPIOs at all is fine, else return the error */
2495 if (nb == 0 || nb == -ENOENT)
2500 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
2504 ctlr->cs_gpiods = cs;
2506 for (i = 0; i < nb; i++) {
2508 * Most chipselects are active low, the inverted
2509 * semantics are handled by special quirks in gpiolib,
2510 * so initializing them GPIOD_OUT_LOW here means
2511 * "unasserted", in most cases this will drive the physical
2514 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
2517 return PTR_ERR(cs[i]);
2521 * If we find a CS GPIO, name it after the device and
2526 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
2530 gpiod_set_consumer_name(cs[i], gpioname);
2535 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
2536 dev_err(dev, "Invalid native chip select %d\n", i);
2539 native_cs_mask |= BIT(i);
2542 ctlr->unused_native_cs = ffz(native_cs_mask);
2543 if (num_cs_gpios && ctlr->max_native_cs &&
2544 ctlr->unused_native_cs >= ctlr->max_native_cs) {
2545 dev_err(dev, "No unused native chip select available\n");
2552 static int spi_controller_check_ops(struct spi_controller *ctlr)
2555 * The controller may implement only the high-level SPI-memory like
2556 * operations if it does not support regular SPI transfers, and this is
2558 * If ->mem_ops is NULL, we request that at least one of the
2559 * ->transfer_xxx() method be implemented.
2561 if (ctlr->mem_ops) {
2562 if (!ctlr->mem_ops->exec_op)
2564 } else if (!ctlr->transfer && !ctlr->transfer_one &&
2565 !ctlr->transfer_one_message) {
2573 * spi_register_controller - register SPI master or slave controller
2574 * @ctlr: initialized master, originally from spi_alloc_master() or
2576 * Context: can sleep
2578 * SPI controllers connect to their drivers using some non-SPI bus,
2579 * such as the platform bus. The final stage of probe() in that code
2580 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2582 * SPI controllers use board specific (often SOC specific) bus numbers,
2583 * and board-specific addressing for SPI devices combines those numbers
2584 * with chip select numbers. Since SPI does not directly support dynamic
2585 * device identification, boards need configuration tables telling which
2586 * chip is at which address.
2588 * This must be called from context that can sleep. It returns zero on
2589 * success, else a negative error code (dropping the controller's refcount).
2590 * After a successful return, the caller is responsible for calling
2591 * spi_unregister_controller().
2593 * Return: zero on success, else a negative error code.
2595 int spi_register_controller(struct spi_controller *ctlr)
2597 struct device *dev = ctlr->dev.parent;
2598 struct boardinfo *bi;
2600 int id, first_dynamic;
2606 * Make sure all necessary hooks are implemented before registering
2607 * the SPI controller.
2609 status = spi_controller_check_ops(ctlr);
2613 if (ctlr->bus_num >= 0) {
2614 /* devices with a fixed bus num must check-in with the num */
2615 mutex_lock(&board_lock);
2616 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2617 ctlr->bus_num + 1, GFP_KERNEL);
2618 mutex_unlock(&board_lock);
2619 if (WARN(id < 0, "couldn't get idr"))
2620 return id == -ENOSPC ? -EBUSY : id;
2622 } else if (ctlr->dev.of_node) {
2623 /* allocate dynamic bus number using Linux idr */
2624 id = of_alias_get_id(ctlr->dev.of_node, "spi");
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;
2635 if (ctlr->bus_num < 0) {
2636 first_dynamic = of_alias_get_highest_id("spi");
2637 if (first_dynamic < 0)
2642 mutex_lock(&board_lock);
2643 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2645 mutex_unlock(&board_lock);
2646 if (WARN(id < 0, "couldn't get idr"))
2650 INIT_LIST_HEAD(&ctlr->queue);
2651 spin_lock_init(&ctlr->queue_lock);
2652 spin_lock_init(&ctlr->bus_lock_spinlock);
2653 mutex_init(&ctlr->bus_lock_mutex);
2654 mutex_init(&ctlr->io_mutex);
2655 ctlr->bus_lock_flag = 0;
2656 init_completion(&ctlr->xfer_completion);
2657 if (!ctlr->max_dma_len)
2658 ctlr->max_dma_len = INT_MAX;
2660 /* register the device, then userspace will see it.
2661 * registration fails if the bus ID is in use.
2663 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2665 if (!spi_controller_is_slave(ctlr)) {
2666 if (ctlr->use_gpio_descriptors) {
2667 status = spi_get_gpio_descs(ctlr);
2671 * A controller using GPIO descriptors always
2672 * supports SPI_CS_HIGH if need be.
2674 ctlr->mode_bits |= SPI_CS_HIGH;
2676 /* Legacy code path for GPIOs from DT */
2677 status = of_spi_get_gpio_numbers(ctlr);
2684 * Even if it's just one always-selected device, there must
2685 * be at least one chipselect.
2687 if (!ctlr->num_chipselect) {
2692 status = device_add(&ctlr->dev);
2695 dev_dbg(dev, "registered %s %s\n",
2696 spi_controller_is_slave(ctlr) ? "slave" : "master",
2697 dev_name(&ctlr->dev));
2700 * If we're using a queued driver, start the queue. Note that we don't
2701 * need the queueing logic if the driver is only supporting high-level
2702 * memory operations.
2704 if (ctlr->transfer) {
2705 dev_info(dev, "controller is unqueued, this is deprecated\n");
2706 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2707 status = spi_controller_initialize_queue(ctlr);
2709 device_del(&ctlr->dev);
2713 /* add statistics */
2714 spin_lock_init(&ctlr->statistics.lock);
2716 mutex_lock(&board_lock);
2717 list_add_tail(&ctlr->list, &spi_controller_list);
2718 list_for_each_entry(bi, &board_list, list)
2719 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2720 mutex_unlock(&board_lock);
2722 /* Register devices from the device tree and ACPI */
2723 of_register_spi_devices(ctlr);
2724 acpi_register_spi_devices(ctlr);
2728 mutex_lock(&board_lock);
2729 idr_remove(&spi_master_idr, ctlr->bus_num);
2730 mutex_unlock(&board_lock);
2733 EXPORT_SYMBOL_GPL(spi_register_controller);
2735 static void devm_spi_unregister(struct device *dev, void *res)
2737 spi_unregister_controller(*(struct spi_controller **)res);
2741 * devm_spi_register_controller - register managed SPI master or slave
2743 * @dev: device managing SPI controller
2744 * @ctlr: initialized controller, originally from spi_alloc_master() or
2746 * Context: can sleep
2748 * Register a SPI device as with spi_register_controller() which will
2749 * automatically be unregistered and freed.
2751 * Return: zero on success, else a negative error code.
2753 int devm_spi_register_controller(struct device *dev,
2754 struct spi_controller *ctlr)
2756 struct spi_controller **ptr;
2759 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2763 ret = spi_register_controller(ctlr);
2766 devres_add(dev, ptr);
2773 EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2775 static int __unregister(struct device *dev, void *null)
2777 spi_unregister_device(to_spi_device(dev));
2782 * spi_unregister_controller - unregister SPI master or slave controller
2783 * @ctlr: the controller being unregistered
2784 * Context: can sleep
2786 * This call is used only by SPI controller drivers, which are the
2787 * only ones directly touching chip registers.
2789 * This must be called from context that can sleep.
2791 * Note that this function also drops a reference to the controller.
2793 void spi_unregister_controller(struct spi_controller *ctlr)
2795 struct spi_controller *found;
2796 int id = ctlr->bus_num;
2798 device_for_each_child(&ctlr->dev, NULL, __unregister);
2800 /* First make sure that this controller was ever added */
2801 mutex_lock(&board_lock);
2802 found = idr_find(&spi_master_idr, id);
2803 mutex_unlock(&board_lock);
2805 if (spi_destroy_queue(ctlr))
2806 dev_err(&ctlr->dev, "queue remove failed\n");
2808 mutex_lock(&board_lock);
2809 list_del(&ctlr->list);
2810 mutex_unlock(&board_lock);
2812 device_unregister(&ctlr->dev);
2814 mutex_lock(&board_lock);
2816 idr_remove(&spi_master_idr, id);
2817 mutex_unlock(&board_lock);
2819 EXPORT_SYMBOL_GPL(spi_unregister_controller);
2821 int spi_controller_suspend(struct spi_controller *ctlr)
2825 /* Basically no-ops for non-queued controllers */
2829 ret = spi_stop_queue(ctlr);
2831 dev_err(&ctlr->dev, "queue stop failed\n");
2835 EXPORT_SYMBOL_GPL(spi_controller_suspend);
2837 int spi_controller_resume(struct spi_controller *ctlr)
2844 ret = spi_start_queue(ctlr);
2846 dev_err(&ctlr->dev, "queue restart failed\n");
2850 EXPORT_SYMBOL_GPL(spi_controller_resume);
2852 static int __spi_controller_match(struct device *dev, const void *data)
2854 struct spi_controller *ctlr;
2855 const u16 *bus_num = data;
2857 ctlr = container_of(dev, struct spi_controller, dev);
2858 return ctlr->bus_num == *bus_num;
2862 * spi_busnum_to_master - look up master associated with bus_num
2863 * @bus_num: the master's bus number
2864 * Context: can sleep
2866 * This call may be used with devices that are registered after
2867 * arch init time. It returns a refcounted pointer to the relevant
2868 * spi_controller (which the caller must release), or NULL if there is
2869 * no such master registered.
2871 * Return: the SPI master structure on success, else NULL.
2873 struct spi_controller *spi_busnum_to_master(u16 bus_num)
2876 struct spi_controller *ctlr = NULL;
2878 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2879 __spi_controller_match);
2881 ctlr = container_of(dev, struct spi_controller, dev);
2882 /* reference got in class_find_device */
2885 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2887 /*-------------------------------------------------------------------------*/
2889 /* Core methods for SPI resource management */
2892 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2893 * during the processing of a spi_message while using
2895 * @spi: the spi device for which we allocate memory
2896 * @release: the release code to execute for this resource
2897 * @size: size to alloc and return
2898 * @gfp: GFP allocation flags
2900 * Return: the pointer to the allocated data
2902 * This may get enhanced in the future to allocate from a memory pool
2903 * of the @spi_device or @spi_controller to avoid repeated allocations.
2905 void *spi_res_alloc(struct spi_device *spi,
2906 spi_res_release_t release,
2907 size_t size, gfp_t gfp)
2909 struct spi_res *sres;
2911 sres = kzalloc(sizeof(*sres) + size, gfp);
2915 INIT_LIST_HEAD(&sres->entry);
2916 sres->release = release;
2920 EXPORT_SYMBOL_GPL(spi_res_alloc);
2923 * spi_res_free - free an spi resource
2924 * @res: pointer to the custom data of a resource
2927 void spi_res_free(void *res)
2929 struct spi_res *sres = container_of(res, struct spi_res, data);
2934 WARN_ON(!list_empty(&sres->entry));
2937 EXPORT_SYMBOL_GPL(spi_res_free);
2940 * spi_res_add - add a spi_res to the spi_message
2941 * @message: the spi message
2942 * @res: the spi_resource
2944 void spi_res_add(struct spi_message *message, void *res)
2946 struct spi_res *sres = container_of(res, struct spi_res, data);
2948 WARN_ON(!list_empty(&sres->entry));
2949 list_add_tail(&sres->entry, &message->resources);
2951 EXPORT_SYMBOL_GPL(spi_res_add);
2954 * spi_res_release - release all spi resources for this message
2955 * @ctlr: the @spi_controller
2956 * @message: the @spi_message
2958 void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
2960 struct spi_res *res, *tmp;
2962 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
2964 res->release(ctlr, message, res->data);
2966 list_del(&res->entry);
2971 EXPORT_SYMBOL_GPL(spi_res_release);
2973 /*-------------------------------------------------------------------------*/
2975 /* Core methods for spi_message alterations */
2977 static void __spi_replace_transfers_release(struct spi_controller *ctlr,
2978 struct spi_message *msg,
2981 struct spi_replaced_transfers *rxfer = res;
2984 /* call extra callback if requested */
2986 rxfer->release(ctlr, msg, res);
2988 /* insert replaced transfers back into the message */
2989 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2991 /* remove the formerly inserted entries */
2992 for (i = 0; i < rxfer->inserted; i++)
2993 list_del(&rxfer->inserted_transfers[i].transfer_list);
2997 * spi_replace_transfers - replace transfers with several transfers
2998 * and register change with spi_message.resources
2999 * @msg: the spi_message we work upon
3000 * @xfer_first: the first spi_transfer we want to replace
3001 * @remove: number of transfers to remove
3002 * @insert: the number of transfers we want to insert instead
3003 * @release: extra release code necessary in some circumstances
3004 * @extradatasize: extra data to allocate (with alignment guarantees
3005 * of struct @spi_transfer)
3008 * Returns: pointer to @spi_replaced_transfers,
3009 * PTR_ERR(...) in case of errors.
3011 struct spi_replaced_transfers *spi_replace_transfers(
3012 struct spi_message *msg,
3013 struct spi_transfer *xfer_first,
3016 spi_replaced_release_t release,
3017 size_t extradatasize,
3020 struct spi_replaced_transfers *rxfer;
3021 struct spi_transfer *xfer;
3024 /* allocate the structure using spi_res */
3025 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
3026 struct_size(rxfer, inserted_transfers, insert)
3030 return ERR_PTR(-ENOMEM);
3032 /* the release code to invoke before running the generic release */
3033 rxfer->release = release;
3035 /* assign extradata */
3038 &rxfer->inserted_transfers[insert];
3040 /* init the replaced_transfers list */
3041 INIT_LIST_HEAD(&rxfer->replaced_transfers);
3043 /* assign the list_entry after which we should reinsert
3044 * the @replaced_transfers - it may be spi_message.messages!
3046 rxfer->replaced_after = xfer_first->transfer_list.prev;
3048 /* remove the requested number of transfers */
3049 for (i = 0; i < remove; i++) {
3050 /* if the entry after replaced_after it is msg->transfers
3051 * then we have been requested to remove more transfers
3052 * than are in the list
3054 if (rxfer->replaced_after->next == &msg->transfers) {
3055 dev_err(&msg->spi->dev,
3056 "requested to remove more spi_transfers than are available\n");
3057 /* insert replaced transfers back into the message */
3058 list_splice(&rxfer->replaced_transfers,
3059 rxfer->replaced_after);
3061 /* free the spi_replace_transfer structure */
3062 spi_res_free(rxfer);
3064 /* and return with an error */
3065 return ERR_PTR(-EINVAL);
3068 /* remove the entry after replaced_after from list of
3069 * transfers and add it to list of replaced_transfers
3071 list_move_tail(rxfer->replaced_after->next,
3072 &rxfer->replaced_transfers);
3075 /* create copy of the given xfer with identical settings
3076 * based on the first transfer to get removed
3078 for (i = 0; i < insert; i++) {
3079 /* we need to run in reverse order */
3080 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3082 /* copy all spi_transfer data */
3083 memcpy(xfer, xfer_first, sizeof(*xfer));
3086 list_add(&xfer->transfer_list, rxfer->replaced_after);
3088 /* clear cs_change and delay for all but the last */
3090 xfer->cs_change = false;
3091 xfer->delay_usecs = 0;
3092 xfer->delay.value = 0;
3096 /* set up inserted */
3097 rxfer->inserted = insert;
3099 /* and register it with spi_res/spi_message */
3100 spi_res_add(msg, rxfer);
3104 EXPORT_SYMBOL_GPL(spi_replace_transfers);
3106 static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3107 struct spi_message *msg,
3108 struct spi_transfer **xferp,
3112 struct spi_transfer *xfer = *xferp, *xfers;
3113 struct spi_replaced_transfers *srt;
3117 /* calculate how many we have to replace */
3118 count = DIV_ROUND_UP(xfer->len, maxsize);
3120 /* create replacement */
3121 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
3123 return PTR_ERR(srt);
3124 xfers = srt->inserted_transfers;
3126 /* now handle each of those newly inserted spi_transfers
3127 * note that the replacements spi_transfers all are preset
3128 * to the same values as *xferp, so tx_buf, rx_buf and len
3129 * are all identical (as well as most others)
3130 * so we just have to fix up len and the pointers.
3132 * this also includes support for the depreciated
3133 * spi_message.is_dma_mapped interface
3136 /* the first transfer just needs the length modified, so we
3137 * run it outside the loop
3139 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3141 /* all the others need rx_buf/tx_buf also set */
3142 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3143 /* update rx_buf, tx_buf and dma */
3144 if (xfers[i].rx_buf)
3145 xfers[i].rx_buf += offset;
3146 if (xfers[i].rx_dma)
3147 xfers[i].rx_dma += offset;
3148 if (xfers[i].tx_buf)
3149 xfers[i].tx_buf += offset;
3150 if (xfers[i].tx_dma)
3151 xfers[i].tx_dma += offset;
3154 xfers[i].len = min(maxsize, xfers[i].len - offset);
3157 /* we set up xferp to the last entry we have inserted,
3158 * so that we skip those already split transfers
3160 *xferp = &xfers[count - 1];
3162 /* increment statistics counters */
3163 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3164 transfers_split_maxsize);
3165 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
3166 transfers_split_maxsize);
3172 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
3173 * when an individual transfer exceeds a
3175 * @ctlr: the @spi_controller for this transfer
3176 * @msg: the @spi_message to transform
3177 * @maxsize: the maximum when to apply this
3178 * @gfp: GFP allocation flags
3180 * Return: status of transformation
3182 int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3183 struct spi_message *msg,
3187 struct spi_transfer *xfer;
3190 /* iterate over the transfer_list,
3191 * but note that xfer is advanced to the last transfer inserted
3192 * to avoid checking sizes again unnecessarily (also xfer does
3193 * potentiall belong to a different list by the time the
3194 * replacement has happened
3196 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3197 if (xfer->len > maxsize) {
3198 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3207 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3209 /*-------------------------------------------------------------------------*/
3211 /* Core methods for SPI controller protocol drivers. Some of the
3212 * other core methods are currently defined as inline functions.
3215 static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3218 if (ctlr->bits_per_word_mask) {
3219 /* Only 32 bits fit in the mask */
3220 if (bits_per_word > 32)
3222 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3230 * spi_setup - setup SPI mode and clock rate
3231 * @spi: the device whose settings are being modified
3232 * Context: can sleep, and no requests are queued to the device
3234 * SPI protocol drivers may need to update the transfer mode if the
3235 * device doesn't work with its default. They may likewise need
3236 * to update clock rates or word sizes from initial values. This function
3237 * changes those settings, and must be called from a context that can sleep.
3238 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3239 * effect the next time the device is selected and data is transferred to
3240 * or from it. When this function returns, the spi device is deselected.
3242 * Note that this call will fail if the protocol driver specifies an option
3243 * that the underlying controller or its driver does not support. For
3244 * example, not all hardware supports wire transfers using nine bit words,
3245 * LSB-first wire encoding, or active-high chipselects.
3247 * Return: zero on success, else a negative error code.
3249 int spi_setup(struct spi_device *spi)
3251 unsigned bad_bits, ugly_bits;
3254 /* check mode to prevent that DUAL and QUAD set at the same time
3256 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
3257 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
3259 "setup: can not select dual and quad at the same time\n");
3262 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
3264 if ((spi->mode & SPI_3WIRE) && (spi->mode &
3265 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3266 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3268 /* help drivers fail *cleanly* when they need options
3269 * that aren't supported with their current controller
3270 * SPI_CS_WORD has a fallback software implementation,
3271 * so it is ignored here.
3273 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
3274 /* nothing prevents from working with active-high CS in case if it
3275 * is driven by GPIO.
3277 if (gpio_is_valid(spi->cs_gpio))
3278 bad_bits &= ~SPI_CS_HIGH;
3279 ugly_bits = bad_bits &
3280 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3281 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3284 "setup: ignoring unsupported mode bits %x\n",
3286 spi->mode &= ~ugly_bits;
3287 bad_bits &= ~ugly_bits;
3290 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3295 if (!spi->bits_per_word)
3296 spi->bits_per_word = 8;
3298 status = __spi_validate_bits_per_word(spi->controller,
3299 spi->bits_per_word);
3303 if (!spi->max_speed_hz)
3304 spi->max_speed_hz = spi->controller->max_speed_hz;
3306 if (spi->controller->setup)
3307 status = spi->controller->setup(spi);
3309 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
3310 status = pm_runtime_get_sync(spi->controller->dev.parent);
3312 pm_runtime_put_noidle(spi->controller->dev.parent);
3313 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3319 * We do not want to return positive value from pm_runtime_get,
3320 * there are many instances of devices calling spi_setup() and
3321 * checking for a non-zero return value instead of a negative
3326 spi_set_cs(spi, false);
3327 pm_runtime_mark_last_busy(spi->controller->dev.parent);
3328 pm_runtime_put_autosuspend(spi->controller->dev.parent);
3330 spi_set_cs(spi, false);
3333 if (spi->rt && !spi->controller->rt) {
3334 spi->controller->rt = true;
3335 spi_set_thread_rt(spi->controller);
3338 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3339 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
3340 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
3341 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
3342 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
3343 (spi->mode & SPI_LOOP) ? "loopback, " : "",
3344 spi->bits_per_word, spi->max_speed_hz,
3349 EXPORT_SYMBOL_GPL(spi_setup);
3352 * spi_set_cs_timing - configure CS setup, hold, and inactive delays
3353 * @spi: the device that requires specific CS timing configuration
3354 * @setup: CS setup time specified via @spi_delay
3355 * @hold: CS hold time specified via @spi_delay
3356 * @inactive: CS inactive delay between transfers specified via @spi_delay
3358 * Return: zero on success, else a negative error code.
3360 int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup,
3361 struct spi_delay *hold, struct spi_delay *inactive)
3365 if (spi->controller->set_cs_timing)
3366 return spi->controller->set_cs_timing(spi, setup, hold,
3369 if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) ||
3370 (hold && hold->unit == SPI_DELAY_UNIT_SCK) ||
3371 (inactive && inactive->unit == SPI_DELAY_UNIT_SCK)) {
3373 "Clock-cycle delays for CS not supported in SW mode\n");
3377 len = sizeof(struct spi_delay);
3379 /* copy delays to controller */
3381 memcpy(&spi->controller->cs_setup, setup, len);
3383 memset(&spi->controller->cs_setup, 0, len);
3386 memcpy(&spi->controller->cs_hold, hold, len);
3388 memset(&spi->controller->cs_hold, 0, len);
3391 memcpy(&spi->controller->cs_inactive, inactive, len);
3393 memset(&spi->controller->cs_inactive, 0, len);
3397 EXPORT_SYMBOL_GPL(spi_set_cs_timing);
3399 static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
3400 struct spi_device *spi)
3404 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
3408 delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
3412 if (delay1 < delay2)
3413 memcpy(&xfer->word_delay, &spi->word_delay,
3414 sizeof(xfer->word_delay));
3419 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
3421 struct spi_controller *ctlr = spi->controller;
3422 struct spi_transfer *xfer;
3425 if (list_empty(&message->transfers))
3428 /* If an SPI controller does not support toggling the CS line on each
3429 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3430 * for the CS line, we can emulate the CS-per-word hardware function by
3431 * splitting transfers into one-word transfers and ensuring that
3432 * cs_change is set for each transfer.
3434 if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
3436 gpio_is_valid(spi->cs_gpio))) {
3440 maxsize = (spi->bits_per_word + 7) / 8;
3442 /* spi_split_transfers_maxsize() requires message->spi */
3445 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
3450 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3451 /* don't change cs_change on the last entry in the list */
3452 if (list_is_last(&xfer->transfer_list, &message->transfers))
3454 xfer->cs_change = 1;
3458 /* Half-duplex links include original MicroWire, and ones with
3459 * only one data pin like SPI_3WIRE (switches direction) or where
3460 * either MOSI or MISO is missing. They can also be caused by
3461 * software limitations.
3463 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
3464 (spi->mode & SPI_3WIRE)) {
3465 unsigned flags = ctlr->flags;
3467 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3468 if (xfer->rx_buf && xfer->tx_buf)
3470 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
3472 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
3478 * Set transfer bits_per_word and max speed as spi device default if
3479 * it is not set for this transfer.
3480 * Set transfer tx_nbits and rx_nbits as single transfer default
3481 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3482 * Ensure transfer word_delay is at least as long as that required by
3485 message->frame_length = 0;
3486 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3487 xfer->effective_speed_hz = 0;
3488 message->frame_length += xfer->len;
3489 if (!xfer->bits_per_word)
3490 xfer->bits_per_word = spi->bits_per_word;
3492 if (!xfer->speed_hz)
3493 xfer->speed_hz = spi->max_speed_hz;
3495 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
3496 xfer->speed_hz = ctlr->max_speed_hz;
3498 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
3502 * SPI transfer length should be multiple of SPI word size
3503 * where SPI word size should be power-of-two multiple
3505 if (xfer->bits_per_word <= 8)
3507 else if (xfer->bits_per_word <= 16)
3512 /* No partial transfers accepted */
3513 if (xfer->len % w_size)
3516 if (xfer->speed_hz && ctlr->min_speed_hz &&
3517 xfer->speed_hz < ctlr->min_speed_hz)
3520 if (xfer->tx_buf && !xfer->tx_nbits)
3521 xfer->tx_nbits = SPI_NBITS_SINGLE;
3522 if (xfer->rx_buf && !xfer->rx_nbits)
3523 xfer->rx_nbits = SPI_NBITS_SINGLE;
3524 /* check transfer tx/rx_nbits:
3525 * 1. check the value matches one of single, dual and quad
3526 * 2. check tx/rx_nbits match the mode in spi_device
3529 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3530 xfer->tx_nbits != SPI_NBITS_DUAL &&
3531 xfer->tx_nbits != SPI_NBITS_QUAD)
3533 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3534 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3536 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3537 !(spi->mode & SPI_TX_QUAD))
3540 /* check transfer rx_nbits */
3542 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3543 xfer->rx_nbits != SPI_NBITS_DUAL &&
3544 xfer->rx_nbits != SPI_NBITS_QUAD)
3546 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3547 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3549 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3550 !(spi->mode & SPI_RX_QUAD))
3554 if (_spi_xfer_word_delay_update(xfer, spi))
3558 message->status = -EINPROGRESS;
3563 static int __spi_async(struct spi_device *spi, struct spi_message *message)
3565 struct spi_controller *ctlr = spi->controller;
3566 struct spi_transfer *xfer;
3569 * Some controllers do not support doing regular SPI transfers. Return
3570 * ENOTSUPP when this is the case.
3572 if (!ctlr->transfer)
3577 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
3578 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3580 trace_spi_message_submit(message);
3582 if (!ctlr->ptp_sts_supported) {
3583 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3584 xfer->ptp_sts_word_pre = 0;
3585 ptp_read_system_prets(xfer->ptp_sts);
3589 return ctlr->transfer(spi, message);
3593 * spi_async - asynchronous SPI transfer
3594 * @spi: device with which data will be exchanged
3595 * @message: describes the data transfers, including completion callback
3596 * Context: any (irqs may be blocked, etc)
3598 * This call may be used in_irq and other contexts which can't sleep,
3599 * as well as from task contexts which can sleep.
3601 * The completion callback is invoked in a context which can't sleep.
3602 * Before that invocation, the value of message->status is undefined.
3603 * When the callback is issued, message->status holds either zero (to
3604 * indicate complete success) or a negative error code. After that
3605 * callback returns, the driver which issued the transfer request may
3606 * deallocate the associated memory; it's no longer in use by any SPI
3607 * core or controller driver code.
3609 * Note that although all messages to a spi_device are handled in
3610 * FIFO order, messages may go to different devices in other orders.
3611 * Some device might be higher priority, or have various "hard" access
3612 * time requirements, for example.
3614 * On detection of any fault during the transfer, processing of
3615 * the entire message is aborted, and the device is deselected.
3616 * Until returning from the associated message completion callback,
3617 * no other spi_message queued to that device will be processed.
3618 * (This rule applies equally to all the synchronous transfer calls,
3619 * which are wrappers around this core asynchronous primitive.)
3621 * Return: zero on success, else a negative error code.
3623 int spi_async(struct spi_device *spi, struct spi_message *message)
3625 struct spi_controller *ctlr = spi->controller;
3627 unsigned long flags;
3629 ret = __spi_validate(spi, message);
3633 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3635 if (ctlr->bus_lock_flag)
3638 ret = __spi_async(spi, message);
3640 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3644 EXPORT_SYMBOL_GPL(spi_async);
3647 * spi_async_locked - version of spi_async with exclusive bus usage
3648 * @spi: device with which data will be exchanged
3649 * @message: describes the data transfers, including completion callback
3650 * Context: any (irqs may be blocked, etc)
3652 * This call may be used in_irq and other contexts which can't sleep,
3653 * as well as from task contexts which can sleep.
3655 * The completion callback is invoked in a context which can't sleep.
3656 * Before that invocation, the value of message->status is undefined.
3657 * When the callback is issued, message->status holds either zero (to
3658 * indicate complete success) or a negative error code. After that
3659 * callback returns, the driver which issued the transfer request may
3660 * deallocate the associated memory; it's no longer in use by any SPI
3661 * core or controller driver code.
3663 * Note that although all messages to a spi_device are handled in
3664 * FIFO order, messages may go to different devices in other orders.
3665 * Some device might be higher priority, or have various "hard" access
3666 * time requirements, for example.
3668 * On detection of any fault during the transfer, processing of
3669 * the entire message is aborted, and the device is deselected.
3670 * Until returning from the associated message completion callback,
3671 * no other spi_message queued to that device will be processed.
3672 * (This rule applies equally to all the synchronous transfer calls,
3673 * which are wrappers around this core asynchronous primitive.)
3675 * Return: zero on success, else a negative error code.
3677 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3679 struct spi_controller *ctlr = spi->controller;
3681 unsigned long flags;
3683 ret = __spi_validate(spi, message);
3687 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3689 ret = __spi_async(spi, message);
3691 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3696 EXPORT_SYMBOL_GPL(spi_async_locked);
3698 /*-------------------------------------------------------------------------*/
3700 /* Utility methods for SPI protocol drivers, layered on
3701 * top of the core. Some other utility methods are defined as
3705 static void spi_complete(void *arg)
3710 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3712 DECLARE_COMPLETION_ONSTACK(done);
3714 struct spi_controller *ctlr = spi->controller;
3715 unsigned long flags;
3717 status = __spi_validate(spi, message);
3721 message->complete = spi_complete;
3722 message->context = &done;
3725 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3726 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3728 /* If we're not using the legacy transfer method then we will
3729 * try to transfer in the calling context so special case.
3730 * This code would be less tricky if we could remove the
3731 * support for driver implemented message queues.
3733 if (ctlr->transfer == spi_queued_transfer) {
3734 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3736 trace_spi_message_submit(message);
3738 status = __spi_queued_transfer(spi, message, false);
3740 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3742 status = spi_async_locked(spi, message);
3746 /* Push out the messages in the calling context if we
3749 if (ctlr->transfer == spi_queued_transfer) {
3750 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3751 spi_sync_immediate);
3752 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3753 spi_sync_immediate);
3754 __spi_pump_messages(ctlr, false);
3757 wait_for_completion(&done);
3758 status = message->status;
3760 message->context = NULL;
3765 * spi_sync - blocking/synchronous SPI data transfers
3766 * @spi: device with which data will be exchanged
3767 * @message: describes the data transfers
3768 * Context: can sleep
3770 * This call may only be used from a context that may sleep. The sleep
3771 * is non-interruptible, and has no timeout. Low-overhead controller
3772 * drivers may DMA directly into and out of the message buffers.
3774 * Note that the SPI device's chip select is active during the message,
3775 * and then is normally disabled between messages. Drivers for some
3776 * frequently-used devices may want to minimize costs of selecting a chip,
3777 * by leaving it selected in anticipation that the next message will go
3778 * to the same chip. (That may increase power usage.)
3780 * Also, the caller is guaranteeing that the memory associated with the
3781 * message will not be freed before this call returns.
3783 * Return: zero on success, else a negative error code.
3785 int spi_sync(struct spi_device *spi, struct spi_message *message)
3789 mutex_lock(&spi->controller->bus_lock_mutex);
3790 ret = __spi_sync(spi, message);
3791 mutex_unlock(&spi->controller->bus_lock_mutex);
3795 EXPORT_SYMBOL_GPL(spi_sync);
3798 * spi_sync_locked - version of spi_sync with exclusive bus usage
3799 * @spi: device with which data will be exchanged
3800 * @message: describes the data transfers
3801 * Context: can sleep
3803 * This call may only be used from a context that may sleep. The sleep
3804 * is non-interruptible, and has no timeout. Low-overhead controller
3805 * drivers may DMA directly into and out of the message buffers.
3807 * This call should be used by drivers that require exclusive access to the
3808 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3809 * be released by a spi_bus_unlock call when the exclusive access is over.
3811 * Return: zero on success, else a negative error code.
3813 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3815 return __spi_sync(spi, message);
3817 EXPORT_SYMBOL_GPL(spi_sync_locked);
3820 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3821 * @ctlr: SPI bus master that should be locked for exclusive bus access
3822 * Context: can sleep
3824 * This call may only be used from a context that may sleep. The sleep
3825 * is non-interruptible, and has no timeout.
3827 * This call should be used by drivers that require exclusive access to the
3828 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3829 * exclusive access is over. Data transfer must be done by spi_sync_locked
3830 * and spi_async_locked calls when the SPI bus lock is held.
3832 * Return: always zero.
3834 int spi_bus_lock(struct spi_controller *ctlr)
3836 unsigned long flags;
3838 mutex_lock(&ctlr->bus_lock_mutex);
3840 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3841 ctlr->bus_lock_flag = 1;
3842 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3844 /* mutex remains locked until spi_bus_unlock is called */
3848 EXPORT_SYMBOL_GPL(spi_bus_lock);
3851 * spi_bus_unlock - release the lock for exclusive SPI bus usage
3852 * @ctlr: SPI bus master that was locked for exclusive bus access
3853 * Context: can sleep
3855 * This call may only be used from a context that may sleep. The sleep
3856 * is non-interruptible, and has no timeout.
3858 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3861 * Return: always zero.
3863 int spi_bus_unlock(struct spi_controller *ctlr)
3865 ctlr->bus_lock_flag = 0;
3867 mutex_unlock(&ctlr->bus_lock_mutex);
3871 EXPORT_SYMBOL_GPL(spi_bus_unlock);
3873 /* portable code must never pass more than 32 bytes */
3874 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3879 * spi_write_then_read - SPI synchronous write followed by read
3880 * @spi: device with which data will be exchanged
3881 * @txbuf: data to be written (need not be dma-safe)
3882 * @n_tx: size of txbuf, in bytes
3883 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3884 * @n_rx: size of rxbuf, in bytes
3885 * Context: can sleep
3887 * This performs a half duplex MicroWire style transaction with the
3888 * device, sending txbuf and then reading rxbuf. The return value
3889 * is zero for success, else a negative errno status code.
3890 * This call may only be used from a context that may sleep.
3892 * Parameters to this routine are always copied using a small buffer.
3893 * Performance-sensitive or bulk transfer code should instead use
3894 * spi_{async,sync}() calls with dma-safe buffers.
3896 * Return: zero on success, else a negative error code.
3898 int spi_write_then_read(struct spi_device *spi,
3899 const void *txbuf, unsigned n_tx,
3900 void *rxbuf, unsigned n_rx)
3902 static DEFINE_MUTEX(lock);
3905 struct spi_message message;
3906 struct spi_transfer x[2];
3909 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3910 * copying here, (as a pure convenience thing), but we can
3911 * keep heap costs out of the hot path unless someone else is
3912 * using the pre-allocated buffer or the transfer is too large.
3914 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
3915 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3916 GFP_KERNEL | GFP_DMA);
3923 spi_message_init(&message);
3924 memset(x, 0, sizeof(x));
3927 spi_message_add_tail(&x[0], &message);
3931 spi_message_add_tail(&x[1], &message);
3934 memcpy(local_buf, txbuf, n_tx);
3935 x[0].tx_buf = local_buf;
3936 x[1].rx_buf = local_buf + n_tx;
3939 status = spi_sync(spi, &message);
3941 memcpy(rxbuf, x[1].rx_buf, n_rx);
3943 if (x[0].tx_buf == buf)
3944 mutex_unlock(&lock);
3950 EXPORT_SYMBOL_GPL(spi_write_then_read);
3952 /*-------------------------------------------------------------------------*/
3954 #if IS_ENABLED(CONFIG_OF)
3955 /* must call put_device() when done with returned spi_device device */
3956 struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3958 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
3960 return dev ? to_spi_device(dev) : NULL;
3962 EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
3963 #endif /* IS_ENABLED(CONFIG_OF) */
3965 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
3966 /* the spi controllers are not using spi_bus, so we find it with another way */
3967 static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
3971 dev = class_find_device_by_of_node(&spi_master_class, node);
3972 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3973 dev = class_find_device_by_of_node(&spi_slave_class, node);
3977 /* reference got in class_find_device */
3978 return container_of(dev, struct spi_controller, dev);
3981 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3984 struct of_reconfig_data *rd = arg;
3985 struct spi_controller *ctlr;
3986 struct spi_device *spi;
3988 switch (of_reconfig_get_state_change(action, arg)) {
3989 case OF_RECONFIG_CHANGE_ADD:
3990 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
3992 return NOTIFY_OK; /* not for us */
3994 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3995 put_device(&ctlr->dev);
3999 spi = of_register_spi_device(ctlr, rd->dn);
4000 put_device(&ctlr->dev);
4003 pr_err("%s: failed to create for '%pOF'\n",
4005 of_node_clear_flag(rd->dn, OF_POPULATED);
4006 return notifier_from_errno(PTR_ERR(spi));
4010 case OF_RECONFIG_CHANGE_REMOVE:
4011 /* already depopulated? */
4012 if (!of_node_check_flag(rd->dn, OF_POPULATED))
4015 /* find our device by node */
4016 spi = of_find_spi_device_by_node(rd->dn);
4018 return NOTIFY_OK; /* no? not meant for us */
4020 /* unregister takes one ref away */
4021 spi_unregister_device(spi);
4023 /* and put the reference of the find */
4024 put_device(&spi->dev);
4031 static struct notifier_block spi_of_notifier = {
4032 .notifier_call = of_spi_notify,
4034 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4035 extern struct notifier_block spi_of_notifier;
4036 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4038 #if IS_ENABLED(CONFIG_ACPI)
4039 static int spi_acpi_controller_match(struct device *dev, const void *data)
4041 return ACPI_COMPANION(dev->parent) == data;
4044 static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4048 dev = class_find_device(&spi_master_class, NULL, adev,
4049 spi_acpi_controller_match);
4050 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4051 dev = class_find_device(&spi_slave_class, NULL, adev,
4052 spi_acpi_controller_match);
4056 return container_of(dev, struct spi_controller, dev);
4059 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4063 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4064 return to_spi_device(dev);
4067 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4070 struct acpi_device *adev = arg;
4071 struct spi_controller *ctlr;
4072 struct spi_device *spi;
4075 case ACPI_RECONFIG_DEVICE_ADD:
4076 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
4080 acpi_register_spi_device(ctlr, adev);
4081 put_device(&ctlr->dev);
4083 case ACPI_RECONFIG_DEVICE_REMOVE:
4084 if (!acpi_device_enumerated(adev))
4087 spi = acpi_spi_find_device_by_adev(adev);
4091 spi_unregister_device(spi);
4092 put_device(&spi->dev);
4099 static struct notifier_block spi_acpi_notifier = {
4100 .notifier_call = acpi_spi_notify,
4103 extern struct notifier_block spi_acpi_notifier;
4106 static int __init spi_init(void)
4110 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4116 status = bus_register(&spi_bus_type);
4120 status = class_register(&spi_master_class);
4124 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4125 status = class_register(&spi_slave_class);
4130 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4131 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4132 if (IS_ENABLED(CONFIG_ACPI))
4133 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4138 class_unregister(&spi_master_class);
4140 bus_unregister(&spi_bus_type);
4148 /* board_info is normally registered in arch_initcall(),
4149 * but even essential drivers wait till later
4151 * REVISIT only boardinfo really needs static linking. the rest (device and
4152 * driver registration) _could_ be dynamically linked (modular) ... costs
4153 * include needing to have boardinfo data structures be much more public.
4155 postcore_initcall(spi_init);