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;
781 if (!spi->controller->set_cs_timing) {
783 spi_delay_exec(&spi->controller->cs_setup, NULL);
785 spi_delay_exec(&spi->controller->cs_hold, NULL);
788 if (spi->mode & SPI_CS_HIGH)
791 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
793 * Honour the SPI_NO_CS flag and invert the enable line, as
794 * active low is default for SPI. Execution paths that handle
795 * polarity inversion in gpiolib (such as device tree) will
796 * enforce active high using the SPI_CS_HIGH resulting in a
797 * double inversion through the code above.
799 if (!(spi->mode & SPI_NO_CS)) {
801 gpiod_set_value_cansleep(spi->cs_gpiod,
804 gpio_set_value_cansleep(spi->cs_gpio, !enable);
806 /* Some SPI masters need both GPIO CS & slave_select */
807 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
808 spi->controller->set_cs)
809 spi->controller->set_cs(spi, !enable);
810 } else if (spi->controller->set_cs) {
811 spi->controller->set_cs(spi, !enable);
814 if (!spi->controller->set_cs_timing) {
816 spi_delay_exec(&spi->controller->cs_inactive, NULL);
820 #ifdef CONFIG_HAS_DMA
821 int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
822 struct sg_table *sgt, void *buf, size_t len,
823 enum dma_data_direction dir)
825 const bool vmalloced_buf = is_vmalloc_addr(buf);
826 unsigned int max_seg_size = dma_get_max_seg_size(dev);
827 #ifdef CONFIG_HIGHMEM
828 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
829 (unsigned long)buf < (PKMAP_BASE +
830 (LAST_PKMAP * PAGE_SIZE)));
832 const bool kmap_buf = false;
836 struct page *vm_page;
837 struct scatterlist *sg;
842 if (vmalloced_buf || kmap_buf) {
843 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
844 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
845 } else if (virt_addr_valid(buf)) {
846 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
847 sgs = DIV_ROUND_UP(len, desc_len);
852 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
857 for (i = 0; i < sgs; i++) {
859 if (vmalloced_buf || kmap_buf) {
861 * Next scatterlist entry size is the minimum between
862 * the desc_len and the remaining buffer length that
865 min = min_t(size_t, desc_len,
867 PAGE_SIZE - offset_in_page(buf)));
869 vm_page = vmalloc_to_page(buf);
871 vm_page = kmap_to_page(buf);
876 sg_set_page(sg, vm_page,
877 min, offset_in_page(buf));
879 min = min_t(size_t, len, desc_len);
881 sg_set_buf(sg, sg_buf, min);
889 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
902 void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
903 struct sg_table *sgt, enum dma_data_direction dir)
905 if (sgt->orig_nents) {
906 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
911 static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
913 struct device *tx_dev, *rx_dev;
914 struct spi_transfer *xfer;
921 tx_dev = ctlr->dma_tx->device->dev;
923 tx_dev = ctlr->dev.parent;
926 rx_dev = ctlr->dma_rx->device->dev;
928 rx_dev = ctlr->dev.parent;
930 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
931 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
934 if (xfer->tx_buf != NULL) {
935 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
936 (void *)xfer->tx_buf, xfer->len,
942 if (xfer->rx_buf != NULL) {
943 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
944 xfer->rx_buf, xfer->len,
947 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
954 ctlr->cur_msg_mapped = true;
959 static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
961 struct spi_transfer *xfer;
962 struct device *tx_dev, *rx_dev;
964 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
968 tx_dev = ctlr->dma_tx->device->dev;
970 tx_dev = ctlr->dev.parent;
973 rx_dev = ctlr->dma_rx->device->dev;
975 rx_dev = ctlr->dev.parent;
977 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
978 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
981 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
982 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
987 #else /* !CONFIG_HAS_DMA */
988 static inline int __spi_map_msg(struct spi_controller *ctlr,
989 struct spi_message *msg)
994 static inline int __spi_unmap_msg(struct spi_controller *ctlr,
995 struct spi_message *msg)
999 #endif /* !CONFIG_HAS_DMA */
1001 static inline int spi_unmap_msg(struct spi_controller *ctlr,
1002 struct spi_message *msg)
1004 struct spi_transfer *xfer;
1006 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1008 * Restore the original value of tx_buf or rx_buf if they are
1011 if (xfer->tx_buf == ctlr->dummy_tx)
1012 xfer->tx_buf = NULL;
1013 if (xfer->rx_buf == ctlr->dummy_rx)
1014 xfer->rx_buf = NULL;
1017 return __spi_unmap_msg(ctlr, msg);
1020 static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1022 struct spi_transfer *xfer;
1024 unsigned int max_tx, max_rx;
1026 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1027 && !(msg->spi->mode & SPI_3WIRE)) {
1031 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1032 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1034 max_tx = max(xfer->len, max_tx);
1035 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1037 max_rx = max(xfer->len, max_rx);
1041 tmp = krealloc(ctlr->dummy_tx, max_tx,
1042 GFP_KERNEL | GFP_DMA);
1045 ctlr->dummy_tx = tmp;
1046 memset(tmp, 0, max_tx);
1050 tmp = krealloc(ctlr->dummy_rx, max_rx,
1051 GFP_KERNEL | GFP_DMA);
1054 ctlr->dummy_rx = tmp;
1057 if (max_tx || max_rx) {
1058 list_for_each_entry(xfer, &msg->transfers,
1063 xfer->tx_buf = ctlr->dummy_tx;
1065 xfer->rx_buf = ctlr->dummy_rx;
1070 return __spi_map_msg(ctlr, msg);
1073 static int spi_transfer_wait(struct spi_controller *ctlr,
1074 struct spi_message *msg,
1075 struct spi_transfer *xfer)
1077 struct spi_statistics *statm = &ctlr->statistics;
1078 struct spi_statistics *stats = &msg->spi->statistics;
1079 unsigned long long ms;
1081 if (spi_controller_is_slave(ctlr)) {
1082 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1083 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1087 ms = 8LL * 1000LL * xfer->len;
1088 do_div(ms, xfer->speed_hz);
1089 ms += ms + 200; /* some tolerance */
1094 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1095 msecs_to_jiffies(ms));
1098 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1099 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1100 dev_err(&msg->spi->dev,
1101 "SPI transfer timed out\n");
1109 static void _spi_transfer_delay_ns(u32 ns)
1116 u32 us = DIV_ROUND_UP(ns, 1000);
1121 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1125 int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1127 u32 delay = _delay->value;
1128 u32 unit = _delay->unit;
1135 case SPI_DELAY_UNIT_USECS:
1138 case SPI_DELAY_UNIT_NSECS: /* nothing to do here */
1140 case SPI_DELAY_UNIT_SCK:
1141 /* clock cycles need to be obtained from spi_transfer */
1144 /* if there is no effective speed know, then approximate
1145 * by underestimating with half the requested hz
1147 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1150 delay *= DIV_ROUND_UP(1000000000, hz);
1158 EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1160 int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1169 delay = spi_delay_to_ns(_delay, xfer);
1173 _spi_transfer_delay_ns(delay);
1177 EXPORT_SYMBOL_GPL(spi_delay_exec);
1179 static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1180 struct spi_transfer *xfer)
1182 u32 delay = xfer->cs_change_delay.value;
1183 u32 unit = xfer->cs_change_delay.unit;
1186 /* return early on "fast" mode - for everything but USECS */
1188 if (unit == SPI_DELAY_UNIT_USECS)
1189 _spi_transfer_delay_ns(10000);
1193 ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1195 dev_err_once(&msg->spi->dev,
1196 "Use of unsupported delay unit %i, using default of 10us\n",
1198 _spi_transfer_delay_ns(10000);
1203 * spi_transfer_one_message - Default implementation of transfer_one_message()
1205 * This is a standard implementation of transfer_one_message() for
1206 * drivers which implement a transfer_one() operation. It provides
1207 * standard handling of delays and chip select management.
1209 static int spi_transfer_one_message(struct spi_controller *ctlr,
1210 struct spi_message *msg)
1212 struct spi_transfer *xfer;
1213 bool keep_cs = false;
1215 struct spi_statistics *statm = &ctlr->statistics;
1216 struct spi_statistics *stats = &msg->spi->statistics;
1218 spi_set_cs(msg->spi, true);
1220 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1221 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1223 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1224 trace_spi_transfer_start(msg, xfer);
1226 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1227 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1229 if (!ctlr->ptp_sts_supported) {
1230 xfer->ptp_sts_word_pre = 0;
1231 ptp_read_system_prets(xfer->ptp_sts);
1234 if (xfer->tx_buf || xfer->rx_buf) {
1235 reinit_completion(&ctlr->xfer_completion);
1237 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1239 SPI_STATISTICS_INCREMENT_FIELD(statm,
1241 SPI_STATISTICS_INCREMENT_FIELD(stats,
1243 dev_err(&msg->spi->dev,
1244 "SPI transfer failed: %d\n", ret);
1249 ret = spi_transfer_wait(ctlr, msg, xfer);
1255 dev_err(&msg->spi->dev,
1256 "Bufferless transfer has length %u\n",
1260 if (!ctlr->ptp_sts_supported) {
1261 ptp_read_system_postts(xfer->ptp_sts);
1262 xfer->ptp_sts_word_post = xfer->len;
1265 trace_spi_transfer_stop(msg, xfer);
1267 if (msg->status != -EINPROGRESS)
1270 spi_transfer_delay_exec(xfer);
1272 if (xfer->cs_change) {
1273 if (list_is_last(&xfer->transfer_list,
1277 spi_set_cs(msg->spi, false);
1278 _spi_transfer_cs_change_delay(msg, xfer);
1279 spi_set_cs(msg->spi, true);
1283 msg->actual_length += xfer->len;
1287 if (ret != 0 || !keep_cs)
1288 spi_set_cs(msg->spi, false);
1290 if (msg->status == -EINPROGRESS)
1293 if (msg->status && ctlr->handle_err)
1294 ctlr->handle_err(ctlr, msg);
1296 spi_res_release(ctlr, msg);
1298 spi_finalize_current_message(ctlr);
1304 * spi_finalize_current_transfer - report completion of a transfer
1305 * @ctlr: the controller reporting completion
1307 * Called by SPI drivers using the core transfer_one_message()
1308 * implementation to notify it that the current interrupt driven
1309 * transfer has finished and the next one may be scheduled.
1311 void spi_finalize_current_transfer(struct spi_controller *ctlr)
1313 complete(&ctlr->xfer_completion);
1315 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1318 * __spi_pump_messages - function which processes spi message queue
1319 * @ctlr: controller to process queue for
1320 * @in_kthread: true if we are in the context of the message pump thread
1322 * This function checks if there is any spi message in the queue that
1323 * needs processing and if so call out to the driver to initialize hardware
1324 * and transfer each message.
1326 * Note that it is called both from the kthread itself and also from
1327 * inside spi_sync(); the queue extraction handling at the top of the
1328 * function should deal with this safely.
1330 static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1332 struct spi_transfer *xfer;
1333 struct spi_message *msg;
1334 bool was_busy = false;
1335 unsigned long flags;
1339 spin_lock_irqsave(&ctlr->queue_lock, flags);
1341 /* Make sure we are not already running a message */
1342 if (ctlr->cur_msg) {
1343 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1347 /* If another context is idling the device then defer */
1349 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1350 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1354 /* Check if the queue is idle */
1355 if (list_empty(&ctlr->queue) || !ctlr->running) {
1357 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1361 /* Only do teardown in the thread */
1363 kthread_queue_work(&ctlr->kworker,
1364 &ctlr->pump_messages);
1365 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1370 ctlr->idling = true;
1371 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1373 kfree(ctlr->dummy_rx);
1374 ctlr->dummy_rx = NULL;
1375 kfree(ctlr->dummy_tx);
1376 ctlr->dummy_tx = NULL;
1377 if (ctlr->unprepare_transfer_hardware &&
1378 ctlr->unprepare_transfer_hardware(ctlr))
1380 "failed to unprepare transfer hardware\n");
1381 if (ctlr->auto_runtime_pm) {
1382 pm_runtime_mark_last_busy(ctlr->dev.parent);
1383 pm_runtime_put_autosuspend(ctlr->dev.parent);
1385 trace_spi_controller_idle(ctlr);
1387 spin_lock_irqsave(&ctlr->queue_lock, flags);
1388 ctlr->idling = false;
1389 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1393 /* Extract head of queue */
1394 msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1395 ctlr->cur_msg = msg;
1397 list_del_init(&msg->queue);
1402 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1404 mutex_lock(&ctlr->io_mutex);
1406 if (!was_busy && ctlr->auto_runtime_pm) {
1407 ret = pm_runtime_get_sync(ctlr->dev.parent);
1409 pm_runtime_put_noidle(ctlr->dev.parent);
1410 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1412 mutex_unlock(&ctlr->io_mutex);
1418 trace_spi_controller_busy(ctlr);
1420 if (!was_busy && ctlr->prepare_transfer_hardware) {
1421 ret = ctlr->prepare_transfer_hardware(ctlr);
1424 "failed to prepare transfer hardware: %d\n",
1427 if (ctlr->auto_runtime_pm)
1428 pm_runtime_put(ctlr->dev.parent);
1431 spi_finalize_current_message(ctlr);
1433 mutex_unlock(&ctlr->io_mutex);
1438 trace_spi_message_start(msg);
1440 if (ctlr->prepare_message) {
1441 ret = ctlr->prepare_message(ctlr, msg);
1443 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1446 spi_finalize_current_message(ctlr);
1449 ctlr->cur_msg_prepared = true;
1452 ret = spi_map_msg(ctlr, msg);
1455 spi_finalize_current_message(ctlr);
1459 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1460 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1461 xfer->ptp_sts_word_pre = 0;
1462 ptp_read_system_prets(xfer->ptp_sts);
1466 ret = ctlr->transfer_one_message(ctlr, msg);
1469 "failed to transfer one message from queue\n");
1474 mutex_unlock(&ctlr->io_mutex);
1476 /* Prod the scheduler in case transfer_one() was busy waiting */
1482 * spi_pump_messages - kthread work function which processes spi message queue
1483 * @work: pointer to kthread work struct contained in the controller struct
1485 static void spi_pump_messages(struct kthread_work *work)
1487 struct spi_controller *ctlr =
1488 container_of(work, struct spi_controller, pump_messages);
1490 __spi_pump_messages(ctlr, true);
1494 * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
1495 * TX timestamp for the requested byte from the SPI
1496 * transfer. The frequency with which this function
1497 * must be called (once per word, once for the whole
1498 * transfer, once per batch of words etc) is arbitrary
1499 * as long as the @tx buffer offset is greater than or
1500 * equal to the requested byte at the time of the
1501 * call. The timestamp is only taken once, at the
1502 * first such call. It is assumed that the driver
1503 * advances its @tx buffer pointer monotonically.
1504 * @ctlr: Pointer to the spi_controller structure of the driver
1505 * @xfer: Pointer to the transfer being timestamped
1506 * @progress: How many words (not bytes) have been transferred so far
1507 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1508 * transfer, for less jitter in time measurement. Only compatible
1509 * with PIO drivers. If true, must follow up with
1510 * spi_take_timestamp_post or otherwise system will crash.
1511 * WARNING: for fully predictable results, the CPU frequency must
1512 * also be under control (governor).
1514 void spi_take_timestamp_pre(struct spi_controller *ctlr,
1515 struct spi_transfer *xfer,
1516 size_t progress, bool irqs_off)
1521 if (xfer->timestamped)
1524 if (progress > xfer->ptp_sts_word_pre)
1527 /* Capture the resolution of the timestamp */
1528 xfer->ptp_sts_word_pre = progress;
1531 local_irq_save(ctlr->irq_flags);
1535 ptp_read_system_prets(xfer->ptp_sts);
1537 EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
1540 * spi_take_timestamp_post - helper for drivers to collect the end of the
1541 * TX timestamp for the requested byte from the SPI
1542 * transfer. Can be called with an arbitrary
1543 * frequency: only the first call where @tx exceeds
1544 * or is equal to the requested word will be
1546 * @ctlr: Pointer to the spi_controller structure of the driver
1547 * @xfer: Pointer to the transfer being timestamped
1548 * @progress: How many words (not bytes) have been transferred so far
1549 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1551 void spi_take_timestamp_post(struct spi_controller *ctlr,
1552 struct spi_transfer *xfer,
1553 size_t progress, bool irqs_off)
1558 if (xfer->timestamped)
1561 if (progress < xfer->ptp_sts_word_post)
1564 ptp_read_system_postts(xfer->ptp_sts);
1567 local_irq_restore(ctlr->irq_flags);
1571 /* Capture the resolution of the timestamp */
1572 xfer->ptp_sts_word_post = progress;
1574 xfer->timestamped = true;
1576 EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
1579 * spi_set_thread_rt - set the controller to pump at realtime priority
1580 * @ctlr: controller to boost priority of
1582 * This can be called because the controller requested realtime priority
1583 * (by setting the ->rt value before calling spi_register_controller()) or
1584 * because a device on the bus said that its transfers needed realtime
1587 * NOTE: at the moment if any device on a bus says it needs realtime then
1588 * the thread will be at realtime priority for all transfers on that
1589 * controller. If this eventually becomes a problem we may see if we can
1590 * find a way to boost the priority only temporarily during relevant
1593 static void spi_set_thread_rt(struct spi_controller *ctlr)
1595 struct sched_param param = { .sched_priority = MAX_RT_PRIO / 2 };
1597 dev_info(&ctlr->dev,
1598 "will run message pump with realtime priority\n");
1599 sched_setscheduler(ctlr->kworker_task, SCHED_FIFO, ¶m);
1602 static int spi_init_queue(struct spi_controller *ctlr)
1604 ctlr->running = false;
1607 kthread_init_worker(&ctlr->kworker);
1608 ctlr->kworker_task = kthread_run(kthread_worker_fn, &ctlr->kworker,
1609 "%s", dev_name(&ctlr->dev));
1610 if (IS_ERR(ctlr->kworker_task)) {
1611 dev_err(&ctlr->dev, "failed to create message pump task\n");
1612 return PTR_ERR(ctlr->kworker_task);
1614 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1617 * Controller config will indicate if this controller should run the
1618 * message pump with high (realtime) priority to reduce the transfer
1619 * latency on the bus by minimising the delay between a transfer
1620 * request and the scheduling of the message pump thread. Without this
1621 * setting the message pump thread will remain at default priority.
1624 spi_set_thread_rt(ctlr);
1630 * spi_get_next_queued_message() - called by driver to check for queued
1632 * @ctlr: the controller to check for queued messages
1634 * If there are more messages in the queue, the next message is returned from
1637 * Return: the next message in the queue, else NULL if the queue is empty.
1639 struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1641 struct spi_message *next;
1642 unsigned long flags;
1644 /* get a pointer to the next message, if any */
1645 spin_lock_irqsave(&ctlr->queue_lock, flags);
1646 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1648 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1652 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1655 * spi_finalize_current_message() - the current message is complete
1656 * @ctlr: the controller to return the message to
1658 * Called by the driver to notify the core that the message in the front of the
1659 * queue is complete and can be removed from the queue.
1661 void spi_finalize_current_message(struct spi_controller *ctlr)
1663 struct spi_transfer *xfer;
1664 struct spi_message *mesg;
1665 unsigned long flags;
1668 spin_lock_irqsave(&ctlr->queue_lock, flags);
1669 mesg = ctlr->cur_msg;
1670 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1672 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1673 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
1674 ptp_read_system_postts(xfer->ptp_sts);
1675 xfer->ptp_sts_word_post = xfer->len;
1679 if (unlikely(ctlr->ptp_sts_supported))
1680 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
1681 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
1683 spi_unmap_msg(ctlr, mesg);
1685 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1686 ret = ctlr->unprepare_message(ctlr, mesg);
1688 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1693 spin_lock_irqsave(&ctlr->queue_lock, flags);
1694 ctlr->cur_msg = NULL;
1695 ctlr->cur_msg_prepared = false;
1696 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1697 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1699 trace_spi_message_done(mesg);
1703 mesg->complete(mesg->context);
1705 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1707 static int spi_start_queue(struct spi_controller *ctlr)
1709 unsigned long flags;
1711 spin_lock_irqsave(&ctlr->queue_lock, flags);
1713 if (ctlr->running || ctlr->busy) {
1714 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1718 ctlr->running = true;
1719 ctlr->cur_msg = NULL;
1720 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1722 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1727 static int spi_stop_queue(struct spi_controller *ctlr)
1729 unsigned long flags;
1730 unsigned limit = 500;
1733 spin_lock_irqsave(&ctlr->queue_lock, flags);
1736 * This is a bit lame, but is optimized for the common execution path.
1737 * A wait_queue on the ctlr->busy could be used, but then the common
1738 * execution path (pump_messages) would be required to call wake_up or
1739 * friends on every SPI message. Do this instead.
1741 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1742 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1743 usleep_range(10000, 11000);
1744 spin_lock_irqsave(&ctlr->queue_lock, flags);
1747 if (!list_empty(&ctlr->queue) || ctlr->busy)
1750 ctlr->running = false;
1752 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1755 dev_warn(&ctlr->dev, "could not stop message queue\n");
1761 static int spi_destroy_queue(struct spi_controller *ctlr)
1765 ret = spi_stop_queue(ctlr);
1768 * kthread_flush_worker will block until all work is done.
1769 * If the reason that stop_queue timed out is that the work will never
1770 * finish, then it does no good to call flush/stop thread, so
1774 dev_err(&ctlr->dev, "problem destroying queue\n");
1778 kthread_flush_worker(&ctlr->kworker);
1779 kthread_stop(ctlr->kworker_task);
1784 static int __spi_queued_transfer(struct spi_device *spi,
1785 struct spi_message *msg,
1788 struct spi_controller *ctlr = spi->controller;
1789 unsigned long flags;
1791 spin_lock_irqsave(&ctlr->queue_lock, flags);
1793 if (!ctlr->running) {
1794 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1797 msg->actual_length = 0;
1798 msg->status = -EINPROGRESS;
1800 list_add_tail(&msg->queue, &ctlr->queue);
1801 if (!ctlr->busy && need_pump)
1802 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1804 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1809 * spi_queued_transfer - transfer function for queued transfers
1810 * @spi: spi device which is requesting transfer
1811 * @msg: spi message which is to handled is queued to driver queue
1813 * Return: zero on success, else a negative error code.
1815 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1817 return __spi_queued_transfer(spi, msg, true);
1820 static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1824 ctlr->transfer = spi_queued_transfer;
1825 if (!ctlr->transfer_one_message)
1826 ctlr->transfer_one_message = spi_transfer_one_message;
1828 /* Initialize and start queue */
1829 ret = spi_init_queue(ctlr);
1831 dev_err(&ctlr->dev, "problem initializing queue\n");
1832 goto err_init_queue;
1834 ctlr->queued = true;
1835 ret = spi_start_queue(ctlr);
1837 dev_err(&ctlr->dev, "problem starting queue\n");
1838 goto err_start_queue;
1844 spi_destroy_queue(ctlr);
1850 * spi_flush_queue - Send all pending messages in the queue from the callers'
1852 * @ctlr: controller to process queue for
1854 * This should be used when one wants to ensure all pending messages have been
1855 * sent before doing something. Is used by the spi-mem code to make sure SPI
1856 * memory operations do not preempt regular SPI transfers that have been queued
1857 * before the spi-mem operation.
1859 void spi_flush_queue(struct spi_controller *ctlr)
1861 if (ctlr->transfer == spi_queued_transfer)
1862 __spi_pump_messages(ctlr, false);
1865 /*-------------------------------------------------------------------------*/
1867 #if defined(CONFIG_OF)
1868 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1869 struct device_node *nc)
1874 /* Mode (clock phase/polarity/etc.) */
1875 if (of_property_read_bool(nc, "spi-cpha"))
1876 spi->mode |= SPI_CPHA;
1877 if (of_property_read_bool(nc, "spi-cpol"))
1878 spi->mode |= SPI_CPOL;
1879 if (of_property_read_bool(nc, "spi-3wire"))
1880 spi->mode |= SPI_3WIRE;
1881 if (of_property_read_bool(nc, "spi-lsb-first"))
1882 spi->mode |= SPI_LSB_FIRST;
1883 if (of_property_read_bool(nc, "spi-cs-high"))
1884 spi->mode |= SPI_CS_HIGH;
1886 /* Device DUAL/QUAD mode */
1887 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1892 spi->mode |= SPI_TX_DUAL;
1895 spi->mode |= SPI_TX_QUAD;
1898 spi->mode |= SPI_TX_OCTAL;
1901 dev_warn(&ctlr->dev,
1902 "spi-tx-bus-width %d not supported\n",
1908 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1913 spi->mode |= SPI_RX_DUAL;
1916 spi->mode |= SPI_RX_QUAD;
1919 spi->mode |= SPI_RX_OCTAL;
1922 dev_warn(&ctlr->dev,
1923 "spi-rx-bus-width %d not supported\n",
1929 if (spi_controller_is_slave(ctlr)) {
1930 if (!of_node_name_eq(nc, "slave")) {
1931 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
1938 /* Device address */
1939 rc = of_property_read_u32(nc, "reg", &value);
1941 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
1945 spi->chip_select = value;
1948 * For descriptors associated with the device, polarity inversion is
1949 * handled in the gpiolib, so all gpio chip selects are "active high"
1950 * in the logical sense, the gpiolib will invert the line if need be.
1952 if ((ctlr->use_gpio_descriptors) && ctlr->cs_gpiods &&
1953 ctlr->cs_gpiods[spi->chip_select])
1954 spi->mode |= SPI_CS_HIGH;
1957 if (!of_property_read_u32(nc, "spi-max-frequency", &value))
1958 spi->max_speed_hz = value;
1963 static struct spi_device *
1964 of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
1966 struct spi_device *spi;
1969 /* Alloc an spi_device */
1970 spi = spi_alloc_device(ctlr);
1972 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
1977 /* Select device driver */
1978 rc = of_modalias_node(nc, spi->modalias,
1979 sizeof(spi->modalias));
1981 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
1985 rc = of_spi_parse_dt(ctlr, spi, nc);
1989 /* Store a pointer to the node in the device structure */
1991 spi->dev.of_node = nc;
1993 /* Register the new device */
1994 rc = spi_add_device(spi);
1996 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
1997 goto err_of_node_put;
2010 * of_register_spi_devices() - Register child devices onto the SPI bus
2011 * @ctlr: Pointer to spi_controller device
2013 * Registers an spi_device for each child node of controller node which
2014 * represents a valid SPI slave.
2016 static void of_register_spi_devices(struct spi_controller *ctlr)
2018 struct spi_device *spi;
2019 struct device_node *nc;
2021 if (!ctlr->dev.of_node)
2024 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2025 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2027 spi = of_register_spi_device(ctlr, nc);
2029 dev_warn(&ctlr->dev,
2030 "Failed to create SPI device for %pOF\n", nc);
2031 of_node_clear_flag(nc, OF_POPULATED);
2036 static void of_register_spi_devices(struct spi_controller *ctlr) { }
2040 struct acpi_spi_lookup {
2041 struct spi_controller *ctlr;
2049 static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2050 struct acpi_spi_lookup *lookup)
2052 const union acpi_object *obj;
2054 if (!x86_apple_machine)
2057 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2058 && obj->buffer.length >= 4)
2059 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2061 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2062 && obj->buffer.length == 8)
2063 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2065 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2066 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2067 lookup->mode |= SPI_LSB_FIRST;
2069 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2070 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2071 lookup->mode |= SPI_CPOL;
2073 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2074 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2075 lookup->mode |= SPI_CPHA;
2078 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2080 struct acpi_spi_lookup *lookup = data;
2081 struct spi_controller *ctlr = lookup->ctlr;
2083 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2084 struct acpi_resource_spi_serialbus *sb;
2085 acpi_handle parent_handle;
2088 sb = &ares->data.spi_serial_bus;
2089 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2091 status = acpi_get_handle(NULL,
2092 sb->resource_source.string_ptr,
2095 if (ACPI_FAILURE(status) ||
2096 ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
2100 * ACPI DeviceSelection numbering is handled by the
2101 * host controller driver in Windows and can vary
2102 * from driver to driver. In Linux we always expect
2103 * 0 .. max - 1 so we need to ask the driver to
2104 * translate between the two schemes.
2106 if (ctlr->fw_translate_cs) {
2107 int cs = ctlr->fw_translate_cs(ctlr,
2108 sb->device_selection);
2111 lookup->chip_select = cs;
2113 lookup->chip_select = sb->device_selection;
2116 lookup->max_speed_hz = sb->connection_speed;
2117 lookup->bits_per_word = sb->data_bit_length;
2119 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2120 lookup->mode |= SPI_CPHA;
2121 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2122 lookup->mode |= SPI_CPOL;
2123 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2124 lookup->mode |= SPI_CS_HIGH;
2126 } else if (lookup->irq < 0) {
2129 if (acpi_dev_resource_interrupt(ares, 0, &r))
2130 lookup->irq = r.start;
2133 /* Always tell the ACPI core to skip this resource */
2137 static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2138 struct acpi_device *adev)
2140 acpi_handle parent_handle = NULL;
2141 struct list_head resource_list;
2142 struct acpi_spi_lookup lookup = {};
2143 struct spi_device *spi;
2146 if (acpi_bus_get_status(adev) || !adev->status.present ||
2147 acpi_device_enumerated(adev))
2153 INIT_LIST_HEAD(&resource_list);
2154 ret = acpi_dev_get_resources(adev, &resource_list,
2155 acpi_spi_add_resource, &lookup);
2156 acpi_dev_free_resource_list(&resource_list);
2159 /* found SPI in _CRS but it points to another controller */
2162 if (!lookup.max_speed_hz &&
2163 !ACPI_FAILURE(acpi_get_parent(adev->handle, &parent_handle)) &&
2164 ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {
2165 /* Apple does not use _CRS but nested devices for SPI slaves */
2166 acpi_spi_parse_apple_properties(adev, &lookup);
2169 if (!lookup.max_speed_hz)
2172 spi = spi_alloc_device(ctlr);
2174 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
2175 dev_name(&adev->dev));
2176 return AE_NO_MEMORY;
2180 ACPI_COMPANION_SET(&spi->dev, adev);
2181 spi->max_speed_hz = lookup.max_speed_hz;
2182 spi->mode |= lookup.mode;
2183 spi->irq = lookup.irq;
2184 spi->bits_per_word = lookup.bits_per_word;
2185 spi->chip_select = lookup.chip_select;
2187 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2188 sizeof(spi->modalias));
2191 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
2193 acpi_device_set_enumerated(adev);
2195 adev->power.flags.ignore_parent = true;
2196 if (spi_add_device(spi)) {
2197 adev->power.flags.ignore_parent = false;
2198 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2199 dev_name(&adev->dev));
2206 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2207 void *data, void **return_value)
2209 struct spi_controller *ctlr = data;
2210 struct acpi_device *adev;
2212 if (acpi_bus_get_device(handle, &adev))
2215 return acpi_register_spi_device(ctlr, adev);
2218 #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2220 static void acpi_register_spi_devices(struct spi_controller *ctlr)
2225 handle = ACPI_HANDLE(ctlr->dev.parent);
2229 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2230 SPI_ACPI_ENUMERATE_MAX_DEPTH,
2231 acpi_spi_add_device, NULL, ctlr, NULL);
2232 if (ACPI_FAILURE(status))
2233 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2236 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2237 #endif /* CONFIG_ACPI */
2239 static void spi_controller_release(struct device *dev)
2241 struct spi_controller *ctlr;
2243 ctlr = container_of(dev, struct spi_controller, dev);
2247 static struct class spi_master_class = {
2248 .name = "spi_master",
2249 .owner = THIS_MODULE,
2250 .dev_release = spi_controller_release,
2251 .dev_groups = spi_master_groups,
2254 #ifdef CONFIG_SPI_SLAVE
2256 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2258 * @spi: device used for the current transfer
2260 int spi_slave_abort(struct spi_device *spi)
2262 struct spi_controller *ctlr = spi->controller;
2264 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
2265 return ctlr->slave_abort(ctlr);
2269 EXPORT_SYMBOL_GPL(spi_slave_abort);
2271 static int match_true(struct device *dev, void *data)
2276 static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2279 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2281 struct device *child;
2283 child = device_find_child(&ctlr->dev, NULL, match_true);
2284 return sprintf(buf, "%s\n",
2285 child ? to_spi_device(child)->modalias : NULL);
2288 static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
2289 const char *buf, size_t count)
2291 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2293 struct spi_device *spi;
2294 struct device *child;
2298 rc = sscanf(buf, "%31s", name);
2299 if (rc != 1 || !name[0])
2302 child = device_find_child(&ctlr->dev, NULL, match_true);
2304 /* Remove registered slave */
2305 device_unregister(child);
2309 if (strcmp(name, "(null)")) {
2310 /* Register new slave */
2311 spi = spi_alloc_device(ctlr);
2315 strlcpy(spi->modalias, name, sizeof(spi->modalias));
2317 rc = spi_add_device(spi);
2327 static DEVICE_ATTR_RW(slave);
2329 static struct attribute *spi_slave_attrs[] = {
2330 &dev_attr_slave.attr,
2334 static const struct attribute_group spi_slave_group = {
2335 .attrs = spi_slave_attrs,
2338 static const struct attribute_group *spi_slave_groups[] = {
2339 &spi_controller_statistics_group,
2344 static struct class spi_slave_class = {
2345 .name = "spi_slave",
2346 .owner = THIS_MODULE,
2347 .dev_release = spi_controller_release,
2348 .dev_groups = spi_slave_groups,
2351 extern struct class spi_slave_class; /* dummy */
2355 * __spi_alloc_controller - allocate an SPI master or slave controller
2356 * @dev: the controller, possibly using the platform_bus
2357 * @size: how much zeroed driver-private data to allocate; the pointer to this
2358 * memory is in the driver_data field of the returned device, accessible
2359 * with spi_controller_get_devdata(); the memory is cacheline aligned;
2360 * drivers granting DMA access to portions of their private data need to
2361 * round up @size using ALIGN(size, dma_get_cache_alignment()).
2362 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2363 * slave (true) controller
2364 * Context: can sleep
2366 * This call is used only by SPI controller drivers, which are the
2367 * only ones directly touching chip registers. It's how they allocate
2368 * an spi_controller structure, prior to calling spi_register_controller().
2370 * This must be called from context that can sleep.
2372 * The caller is responsible for assigning the bus number and initializing the
2373 * controller's methods before calling spi_register_controller(); and (after
2374 * errors adding the device) calling spi_controller_put() to prevent a memory
2377 * Return: the SPI controller structure on success, else NULL.
2379 struct spi_controller *__spi_alloc_controller(struct device *dev,
2380 unsigned int size, bool slave)
2382 struct spi_controller *ctlr;
2383 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
2388 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
2392 device_initialize(&ctlr->dev);
2394 ctlr->num_chipselect = 1;
2395 ctlr->slave = slave;
2396 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2397 ctlr->dev.class = &spi_slave_class;
2399 ctlr->dev.class = &spi_master_class;
2400 ctlr->dev.parent = dev;
2401 pm_suspend_ignore_children(&ctlr->dev, true);
2402 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
2406 EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2409 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2412 struct device_node *np = ctlr->dev.of_node;
2417 nb = of_gpio_named_count(np, "cs-gpios");
2418 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2420 /* Return error only for an incorrectly formed cs-gpios property */
2421 if (nb == 0 || nb == -ENOENT)
2426 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2428 ctlr->cs_gpios = cs;
2430 if (!ctlr->cs_gpios)
2433 for (i = 0; i < ctlr->num_chipselect; i++)
2436 for (i = 0; i < nb; i++)
2437 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2442 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2449 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2450 * @ctlr: The SPI master to grab GPIO descriptors for
2452 static int spi_get_gpio_descs(struct spi_controller *ctlr)
2455 struct gpio_desc **cs;
2456 struct device *dev = &ctlr->dev;
2457 unsigned long native_cs_mask = 0;
2458 unsigned int num_cs_gpios = 0;
2460 nb = gpiod_count(dev, "cs");
2461 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2463 /* No GPIOs at all is fine, else return the error */
2464 if (nb == 0 || nb == -ENOENT)
2469 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
2473 ctlr->cs_gpiods = cs;
2475 for (i = 0; i < nb; i++) {
2477 * Most chipselects are active low, the inverted
2478 * semantics are handled by special quirks in gpiolib,
2479 * so initializing them GPIOD_OUT_LOW here means
2480 * "unasserted", in most cases this will drive the physical
2483 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
2486 return PTR_ERR(cs[i]);
2490 * If we find a CS GPIO, name it after the device and
2495 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
2499 gpiod_set_consumer_name(cs[i], gpioname);
2504 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
2505 dev_err(dev, "Invalid native chip select %d\n", i);
2508 native_cs_mask |= BIT(i);
2511 ctlr->unused_native_cs = ffz(native_cs_mask);
2512 if (num_cs_gpios && ctlr->max_native_cs &&
2513 ctlr->unused_native_cs >= ctlr->max_native_cs) {
2514 dev_err(dev, "No unused native chip select available\n");
2521 static int spi_controller_check_ops(struct spi_controller *ctlr)
2524 * The controller may implement only the high-level SPI-memory like
2525 * operations if it does not support regular SPI transfers, and this is
2527 * If ->mem_ops is NULL, we request that at least one of the
2528 * ->transfer_xxx() method be implemented.
2530 if (ctlr->mem_ops) {
2531 if (!ctlr->mem_ops->exec_op)
2533 } else if (!ctlr->transfer && !ctlr->transfer_one &&
2534 !ctlr->transfer_one_message) {
2542 * spi_register_controller - register SPI master or slave controller
2543 * @ctlr: initialized master, originally from spi_alloc_master() or
2545 * Context: can sleep
2547 * SPI controllers connect to their drivers using some non-SPI bus,
2548 * such as the platform bus. The final stage of probe() in that code
2549 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2551 * SPI controllers use board specific (often SOC specific) bus numbers,
2552 * and board-specific addressing for SPI devices combines those numbers
2553 * with chip select numbers. Since SPI does not directly support dynamic
2554 * device identification, boards need configuration tables telling which
2555 * chip is at which address.
2557 * This must be called from context that can sleep. It returns zero on
2558 * success, else a negative error code (dropping the controller's refcount).
2559 * After a successful return, the caller is responsible for calling
2560 * spi_unregister_controller().
2562 * Return: zero on success, else a negative error code.
2564 int spi_register_controller(struct spi_controller *ctlr)
2566 struct device *dev = ctlr->dev.parent;
2567 struct boardinfo *bi;
2569 int id, first_dynamic;
2575 * Make sure all necessary hooks are implemented before registering
2576 * the SPI controller.
2578 status = spi_controller_check_ops(ctlr);
2582 if (ctlr->bus_num >= 0) {
2583 /* devices with a fixed bus num must check-in with the num */
2584 mutex_lock(&board_lock);
2585 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2586 ctlr->bus_num + 1, GFP_KERNEL);
2587 mutex_unlock(&board_lock);
2588 if (WARN(id < 0, "couldn't get idr"))
2589 return id == -ENOSPC ? -EBUSY : id;
2591 } else if (ctlr->dev.of_node) {
2592 /* allocate dynamic bus number using Linux idr */
2593 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2596 mutex_lock(&board_lock);
2597 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2598 ctlr->bus_num + 1, GFP_KERNEL);
2599 mutex_unlock(&board_lock);
2600 if (WARN(id < 0, "couldn't get idr"))
2601 return id == -ENOSPC ? -EBUSY : id;
2604 if (ctlr->bus_num < 0) {
2605 first_dynamic = of_alias_get_highest_id("spi");
2606 if (first_dynamic < 0)
2611 mutex_lock(&board_lock);
2612 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2614 mutex_unlock(&board_lock);
2615 if (WARN(id < 0, "couldn't get idr"))
2619 INIT_LIST_HEAD(&ctlr->queue);
2620 spin_lock_init(&ctlr->queue_lock);
2621 spin_lock_init(&ctlr->bus_lock_spinlock);
2622 mutex_init(&ctlr->bus_lock_mutex);
2623 mutex_init(&ctlr->io_mutex);
2624 ctlr->bus_lock_flag = 0;
2625 init_completion(&ctlr->xfer_completion);
2626 if (!ctlr->max_dma_len)
2627 ctlr->max_dma_len = INT_MAX;
2629 /* register the device, then userspace will see it.
2630 * registration fails if the bus ID is in use.
2632 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2634 if (!spi_controller_is_slave(ctlr)) {
2635 if (ctlr->use_gpio_descriptors) {
2636 status = spi_get_gpio_descs(ctlr);
2640 * A controller using GPIO descriptors always
2641 * supports SPI_CS_HIGH if need be.
2643 ctlr->mode_bits |= SPI_CS_HIGH;
2645 /* Legacy code path for GPIOs from DT */
2646 status = of_spi_get_gpio_numbers(ctlr);
2653 * Even if it's just one always-selected device, there must
2654 * be at least one chipselect.
2656 if (!ctlr->num_chipselect) {
2661 status = device_add(&ctlr->dev);
2664 dev_dbg(dev, "registered %s %s\n",
2665 spi_controller_is_slave(ctlr) ? "slave" : "master",
2666 dev_name(&ctlr->dev));
2669 * If we're using a queued driver, start the queue. Note that we don't
2670 * need the queueing logic if the driver is only supporting high-level
2671 * memory operations.
2673 if (ctlr->transfer) {
2674 dev_info(dev, "controller is unqueued, this is deprecated\n");
2675 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2676 status = spi_controller_initialize_queue(ctlr);
2678 device_del(&ctlr->dev);
2682 /* add statistics */
2683 spin_lock_init(&ctlr->statistics.lock);
2685 mutex_lock(&board_lock);
2686 list_add_tail(&ctlr->list, &spi_controller_list);
2687 list_for_each_entry(bi, &board_list, list)
2688 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2689 mutex_unlock(&board_lock);
2691 /* Register devices from the device tree and ACPI */
2692 of_register_spi_devices(ctlr);
2693 acpi_register_spi_devices(ctlr);
2697 mutex_lock(&board_lock);
2698 idr_remove(&spi_master_idr, ctlr->bus_num);
2699 mutex_unlock(&board_lock);
2702 EXPORT_SYMBOL_GPL(spi_register_controller);
2704 static void devm_spi_unregister(struct device *dev, void *res)
2706 spi_unregister_controller(*(struct spi_controller **)res);
2710 * devm_spi_register_controller - register managed SPI master or slave
2712 * @dev: device managing SPI controller
2713 * @ctlr: initialized controller, originally from spi_alloc_master() or
2715 * Context: can sleep
2717 * Register a SPI device as with spi_register_controller() which will
2718 * automatically be unregistered and freed.
2720 * Return: zero on success, else a negative error code.
2722 int devm_spi_register_controller(struct device *dev,
2723 struct spi_controller *ctlr)
2725 struct spi_controller **ptr;
2728 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2732 ret = spi_register_controller(ctlr);
2735 devres_add(dev, ptr);
2742 EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2744 static int __unregister(struct device *dev, void *null)
2746 spi_unregister_device(to_spi_device(dev));
2751 * spi_unregister_controller - unregister SPI master or slave controller
2752 * @ctlr: the controller being unregistered
2753 * Context: can sleep
2755 * This call is used only by SPI controller drivers, which are the
2756 * only ones directly touching chip registers.
2758 * This must be called from context that can sleep.
2760 * Note that this function also drops a reference to the controller.
2762 void spi_unregister_controller(struct spi_controller *ctlr)
2764 struct spi_controller *found;
2765 int id = ctlr->bus_num;
2767 device_for_each_child(&ctlr->dev, NULL, __unregister);
2769 /* First make sure that this controller was ever added */
2770 mutex_lock(&board_lock);
2771 found = idr_find(&spi_master_idr, id);
2772 mutex_unlock(&board_lock);
2774 if (spi_destroy_queue(ctlr))
2775 dev_err(&ctlr->dev, "queue remove failed\n");
2777 mutex_lock(&board_lock);
2778 list_del(&ctlr->list);
2779 mutex_unlock(&board_lock);
2781 device_unregister(&ctlr->dev);
2783 mutex_lock(&board_lock);
2785 idr_remove(&spi_master_idr, id);
2786 mutex_unlock(&board_lock);
2788 EXPORT_SYMBOL_GPL(spi_unregister_controller);
2790 int spi_controller_suspend(struct spi_controller *ctlr)
2794 /* Basically no-ops for non-queued controllers */
2798 ret = spi_stop_queue(ctlr);
2800 dev_err(&ctlr->dev, "queue stop failed\n");
2804 EXPORT_SYMBOL_GPL(spi_controller_suspend);
2806 int spi_controller_resume(struct spi_controller *ctlr)
2813 ret = spi_start_queue(ctlr);
2815 dev_err(&ctlr->dev, "queue restart failed\n");
2819 EXPORT_SYMBOL_GPL(spi_controller_resume);
2821 static int __spi_controller_match(struct device *dev, const void *data)
2823 struct spi_controller *ctlr;
2824 const u16 *bus_num = data;
2826 ctlr = container_of(dev, struct spi_controller, dev);
2827 return ctlr->bus_num == *bus_num;
2831 * spi_busnum_to_master - look up master associated with bus_num
2832 * @bus_num: the master's bus number
2833 * Context: can sleep
2835 * This call may be used with devices that are registered after
2836 * arch init time. It returns a refcounted pointer to the relevant
2837 * spi_controller (which the caller must release), or NULL if there is
2838 * no such master registered.
2840 * Return: the SPI master structure on success, else NULL.
2842 struct spi_controller *spi_busnum_to_master(u16 bus_num)
2845 struct spi_controller *ctlr = NULL;
2847 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2848 __spi_controller_match);
2850 ctlr = container_of(dev, struct spi_controller, dev);
2851 /* reference got in class_find_device */
2854 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2856 /*-------------------------------------------------------------------------*/
2858 /* Core methods for SPI resource management */
2861 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2862 * during the processing of a spi_message while using
2864 * @spi: the spi device for which we allocate memory
2865 * @release: the release code to execute for this resource
2866 * @size: size to alloc and return
2867 * @gfp: GFP allocation flags
2869 * Return: the pointer to the allocated data
2871 * This may get enhanced in the future to allocate from a memory pool
2872 * of the @spi_device or @spi_controller to avoid repeated allocations.
2874 void *spi_res_alloc(struct spi_device *spi,
2875 spi_res_release_t release,
2876 size_t size, gfp_t gfp)
2878 struct spi_res *sres;
2880 sres = kzalloc(sizeof(*sres) + size, gfp);
2884 INIT_LIST_HEAD(&sres->entry);
2885 sres->release = release;
2889 EXPORT_SYMBOL_GPL(spi_res_alloc);
2892 * spi_res_free - free an spi resource
2893 * @res: pointer to the custom data of a resource
2896 void spi_res_free(void *res)
2898 struct spi_res *sres = container_of(res, struct spi_res, data);
2903 WARN_ON(!list_empty(&sres->entry));
2906 EXPORT_SYMBOL_GPL(spi_res_free);
2909 * spi_res_add - add a spi_res to the spi_message
2910 * @message: the spi message
2911 * @res: the spi_resource
2913 void spi_res_add(struct spi_message *message, void *res)
2915 struct spi_res *sres = container_of(res, struct spi_res, data);
2917 WARN_ON(!list_empty(&sres->entry));
2918 list_add_tail(&sres->entry, &message->resources);
2920 EXPORT_SYMBOL_GPL(spi_res_add);
2923 * spi_res_release - release all spi resources for this message
2924 * @ctlr: the @spi_controller
2925 * @message: the @spi_message
2927 void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
2929 struct spi_res *res, *tmp;
2931 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
2933 res->release(ctlr, message, res->data);
2935 list_del(&res->entry);
2940 EXPORT_SYMBOL_GPL(spi_res_release);
2942 /*-------------------------------------------------------------------------*/
2944 /* Core methods for spi_message alterations */
2946 static void __spi_replace_transfers_release(struct spi_controller *ctlr,
2947 struct spi_message *msg,
2950 struct spi_replaced_transfers *rxfer = res;
2953 /* call extra callback if requested */
2955 rxfer->release(ctlr, msg, res);
2957 /* insert replaced transfers back into the message */
2958 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2960 /* remove the formerly inserted entries */
2961 for (i = 0; i < rxfer->inserted; i++)
2962 list_del(&rxfer->inserted_transfers[i].transfer_list);
2966 * spi_replace_transfers - replace transfers with several transfers
2967 * and register change with spi_message.resources
2968 * @msg: the spi_message we work upon
2969 * @xfer_first: the first spi_transfer we want to replace
2970 * @remove: number of transfers to remove
2971 * @insert: the number of transfers we want to insert instead
2972 * @release: extra release code necessary in some circumstances
2973 * @extradatasize: extra data to allocate (with alignment guarantees
2974 * of struct @spi_transfer)
2977 * Returns: pointer to @spi_replaced_transfers,
2978 * PTR_ERR(...) in case of errors.
2980 struct spi_replaced_transfers *spi_replace_transfers(
2981 struct spi_message *msg,
2982 struct spi_transfer *xfer_first,
2985 spi_replaced_release_t release,
2986 size_t extradatasize,
2989 struct spi_replaced_transfers *rxfer;
2990 struct spi_transfer *xfer;
2993 /* allocate the structure using spi_res */
2994 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2995 struct_size(rxfer, inserted_transfers, insert)
2999 return ERR_PTR(-ENOMEM);
3001 /* the release code to invoke before running the generic release */
3002 rxfer->release = release;
3004 /* assign extradata */
3007 &rxfer->inserted_transfers[insert];
3009 /* init the replaced_transfers list */
3010 INIT_LIST_HEAD(&rxfer->replaced_transfers);
3012 /* assign the list_entry after which we should reinsert
3013 * the @replaced_transfers - it may be spi_message.messages!
3015 rxfer->replaced_after = xfer_first->transfer_list.prev;
3017 /* remove the requested number of transfers */
3018 for (i = 0; i < remove; i++) {
3019 /* if the entry after replaced_after it is msg->transfers
3020 * then we have been requested to remove more transfers
3021 * than are in the list
3023 if (rxfer->replaced_after->next == &msg->transfers) {
3024 dev_err(&msg->spi->dev,
3025 "requested to remove more spi_transfers than are available\n");
3026 /* insert replaced transfers back into the message */
3027 list_splice(&rxfer->replaced_transfers,
3028 rxfer->replaced_after);
3030 /* free the spi_replace_transfer structure */
3031 spi_res_free(rxfer);
3033 /* and return with an error */
3034 return ERR_PTR(-EINVAL);
3037 /* remove the entry after replaced_after from list of
3038 * transfers and add it to list of replaced_transfers
3040 list_move_tail(rxfer->replaced_after->next,
3041 &rxfer->replaced_transfers);
3044 /* create copy of the given xfer with identical settings
3045 * based on the first transfer to get removed
3047 for (i = 0; i < insert; i++) {
3048 /* we need to run in reverse order */
3049 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3051 /* copy all spi_transfer data */
3052 memcpy(xfer, xfer_first, sizeof(*xfer));
3055 list_add(&xfer->transfer_list, rxfer->replaced_after);
3057 /* clear cs_change and delay for all but the last */
3059 xfer->cs_change = false;
3060 xfer->delay_usecs = 0;
3061 xfer->delay.value = 0;
3065 /* set up inserted */
3066 rxfer->inserted = insert;
3068 /* and register it with spi_res/spi_message */
3069 spi_res_add(msg, rxfer);
3073 EXPORT_SYMBOL_GPL(spi_replace_transfers);
3075 static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3076 struct spi_message *msg,
3077 struct spi_transfer **xferp,
3081 struct spi_transfer *xfer = *xferp, *xfers;
3082 struct spi_replaced_transfers *srt;
3086 /* calculate how many we have to replace */
3087 count = DIV_ROUND_UP(xfer->len, maxsize);
3089 /* create replacement */
3090 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
3092 return PTR_ERR(srt);
3093 xfers = srt->inserted_transfers;
3095 /* now handle each of those newly inserted spi_transfers
3096 * note that the replacements spi_transfers all are preset
3097 * to the same values as *xferp, so tx_buf, rx_buf and len
3098 * are all identical (as well as most others)
3099 * so we just have to fix up len and the pointers.
3101 * this also includes support for the depreciated
3102 * spi_message.is_dma_mapped interface
3105 /* the first transfer just needs the length modified, so we
3106 * run it outside the loop
3108 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3110 /* all the others need rx_buf/tx_buf also set */
3111 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3112 /* update rx_buf, tx_buf and dma */
3113 if (xfers[i].rx_buf)
3114 xfers[i].rx_buf += offset;
3115 if (xfers[i].rx_dma)
3116 xfers[i].rx_dma += offset;
3117 if (xfers[i].tx_buf)
3118 xfers[i].tx_buf += offset;
3119 if (xfers[i].tx_dma)
3120 xfers[i].tx_dma += offset;
3123 xfers[i].len = min(maxsize, xfers[i].len - offset);
3126 /* we set up xferp to the last entry we have inserted,
3127 * so that we skip those already split transfers
3129 *xferp = &xfers[count - 1];
3131 /* increment statistics counters */
3132 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3133 transfers_split_maxsize);
3134 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
3135 transfers_split_maxsize);
3141 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
3142 * when an individual transfer exceeds a
3144 * @ctlr: the @spi_controller for this transfer
3145 * @msg: the @spi_message to transform
3146 * @maxsize: the maximum when to apply this
3147 * @gfp: GFP allocation flags
3149 * Return: status of transformation
3151 int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3152 struct spi_message *msg,
3156 struct spi_transfer *xfer;
3159 /* iterate over the transfer_list,
3160 * but note that xfer is advanced to the last transfer inserted
3161 * to avoid checking sizes again unnecessarily (also xfer does
3162 * potentiall belong to a different list by the time the
3163 * replacement has happened
3165 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3166 if (xfer->len > maxsize) {
3167 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3176 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3178 /*-------------------------------------------------------------------------*/
3180 /* Core methods for SPI controller protocol drivers. Some of the
3181 * other core methods are currently defined as inline functions.
3184 static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3187 if (ctlr->bits_per_word_mask) {
3188 /* Only 32 bits fit in the mask */
3189 if (bits_per_word > 32)
3191 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3199 * spi_setup - setup SPI mode and clock rate
3200 * @spi: the device whose settings are being modified
3201 * Context: can sleep, and no requests are queued to the device
3203 * SPI protocol drivers may need to update the transfer mode if the
3204 * device doesn't work with its default. They may likewise need
3205 * to update clock rates or word sizes from initial values. This function
3206 * changes those settings, and must be called from a context that can sleep.
3207 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3208 * effect the next time the device is selected and data is transferred to
3209 * or from it. When this function returns, the spi device is deselected.
3211 * Note that this call will fail if the protocol driver specifies an option
3212 * that the underlying controller or its driver does not support. For
3213 * example, not all hardware supports wire transfers using nine bit words,
3214 * LSB-first wire encoding, or active-high chipselects.
3216 * Return: zero on success, else a negative error code.
3218 int spi_setup(struct spi_device *spi)
3220 unsigned bad_bits, ugly_bits;
3223 /* check mode to prevent that DUAL and QUAD set at the same time
3225 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
3226 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
3228 "setup: can not select dual and quad at the same time\n");
3231 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
3233 if ((spi->mode & SPI_3WIRE) && (spi->mode &
3234 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3235 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3237 /* help drivers fail *cleanly* when they need options
3238 * that aren't supported with their current controller
3239 * SPI_CS_WORD has a fallback software implementation,
3240 * so it is ignored here.
3242 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
3243 /* nothing prevents from working with active-high CS in case if it
3244 * is driven by GPIO.
3246 if (gpio_is_valid(spi->cs_gpio))
3247 bad_bits &= ~SPI_CS_HIGH;
3248 ugly_bits = bad_bits &
3249 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3250 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3253 "setup: ignoring unsupported mode bits %x\n",
3255 spi->mode &= ~ugly_bits;
3256 bad_bits &= ~ugly_bits;
3259 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3264 if (!spi->bits_per_word)
3265 spi->bits_per_word = 8;
3267 status = __spi_validate_bits_per_word(spi->controller,
3268 spi->bits_per_word);
3272 if (!spi->max_speed_hz)
3273 spi->max_speed_hz = spi->controller->max_speed_hz;
3275 if (spi->controller->setup)
3276 status = spi->controller->setup(spi);
3278 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
3279 status = pm_runtime_get_sync(spi->controller->dev.parent);
3281 pm_runtime_put_noidle(spi->controller->dev.parent);
3282 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3288 * We do not want to return positive value from pm_runtime_get,
3289 * there are many instances of devices calling spi_setup() and
3290 * checking for a non-zero return value instead of a negative
3295 spi_set_cs(spi, false);
3296 pm_runtime_mark_last_busy(spi->controller->dev.parent);
3297 pm_runtime_put_autosuspend(spi->controller->dev.parent);
3299 spi_set_cs(spi, false);
3302 if (spi->rt && !spi->controller->rt) {
3303 spi->controller->rt = true;
3304 spi_set_thread_rt(spi->controller);
3307 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3308 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
3309 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
3310 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
3311 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
3312 (spi->mode & SPI_LOOP) ? "loopback, " : "",
3313 spi->bits_per_word, spi->max_speed_hz,
3318 EXPORT_SYMBOL_GPL(spi_setup);
3321 * spi_set_cs_timing - configure CS setup, hold, and inactive delays
3322 * @spi: the device that requires specific CS timing configuration
3323 * @setup: CS setup time specified via @spi_delay
3324 * @hold: CS hold time specified via @spi_delay
3325 * @inactive: CS inactive delay between transfers specified via @spi_delay
3327 * Return: zero on success, else a negative error code.
3329 int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup,
3330 struct spi_delay *hold, struct spi_delay *inactive)
3334 if (spi->controller->set_cs_timing)
3335 return spi->controller->set_cs_timing(spi, setup, hold,
3338 if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) ||
3339 (hold && hold->unit == SPI_DELAY_UNIT_SCK) ||
3340 (inactive && inactive->unit == SPI_DELAY_UNIT_SCK)) {
3342 "Clock-cycle delays for CS not supported in SW mode\n");
3346 len = sizeof(struct spi_delay);
3348 /* copy delays to controller */
3350 memcpy(&spi->controller->cs_setup, setup, len);
3352 memset(&spi->controller->cs_setup, 0, len);
3355 memcpy(&spi->controller->cs_hold, hold, len);
3357 memset(&spi->controller->cs_hold, 0, len);
3360 memcpy(&spi->controller->cs_inactive, inactive, len);
3362 memset(&spi->controller->cs_inactive, 0, len);
3366 EXPORT_SYMBOL_GPL(spi_set_cs_timing);
3368 static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
3369 struct spi_device *spi)
3373 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
3377 delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
3381 if (delay1 < delay2)
3382 memcpy(&xfer->word_delay, &spi->word_delay,
3383 sizeof(xfer->word_delay));
3388 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
3390 struct spi_controller *ctlr = spi->controller;
3391 struct spi_transfer *xfer;
3394 if (list_empty(&message->transfers))
3397 /* If an SPI controller does not support toggling the CS line on each
3398 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3399 * for the CS line, we can emulate the CS-per-word hardware function by
3400 * splitting transfers into one-word transfers and ensuring that
3401 * cs_change is set for each transfer.
3403 if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
3405 gpio_is_valid(spi->cs_gpio))) {
3409 maxsize = (spi->bits_per_word + 7) / 8;
3411 /* spi_split_transfers_maxsize() requires message->spi */
3414 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
3419 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3420 /* don't change cs_change on the last entry in the list */
3421 if (list_is_last(&xfer->transfer_list, &message->transfers))
3423 xfer->cs_change = 1;
3427 /* Half-duplex links include original MicroWire, and ones with
3428 * only one data pin like SPI_3WIRE (switches direction) or where
3429 * either MOSI or MISO is missing. They can also be caused by
3430 * software limitations.
3432 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
3433 (spi->mode & SPI_3WIRE)) {
3434 unsigned flags = ctlr->flags;
3436 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3437 if (xfer->rx_buf && xfer->tx_buf)
3439 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
3441 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
3447 * Set transfer bits_per_word and max speed as spi device default if
3448 * it is not set for this transfer.
3449 * Set transfer tx_nbits and rx_nbits as single transfer default
3450 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3451 * Ensure transfer word_delay is at least as long as that required by
3454 message->frame_length = 0;
3455 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3456 xfer->effective_speed_hz = 0;
3457 message->frame_length += xfer->len;
3458 if (!xfer->bits_per_word)
3459 xfer->bits_per_word = spi->bits_per_word;
3461 if (!xfer->speed_hz)
3462 xfer->speed_hz = spi->max_speed_hz;
3464 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
3465 xfer->speed_hz = ctlr->max_speed_hz;
3467 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
3471 * SPI transfer length should be multiple of SPI word size
3472 * where SPI word size should be power-of-two multiple
3474 if (xfer->bits_per_word <= 8)
3476 else if (xfer->bits_per_word <= 16)
3481 /* No partial transfers accepted */
3482 if (xfer->len % w_size)
3485 if (xfer->speed_hz && ctlr->min_speed_hz &&
3486 xfer->speed_hz < ctlr->min_speed_hz)
3489 if (xfer->tx_buf && !xfer->tx_nbits)
3490 xfer->tx_nbits = SPI_NBITS_SINGLE;
3491 if (xfer->rx_buf && !xfer->rx_nbits)
3492 xfer->rx_nbits = SPI_NBITS_SINGLE;
3493 /* check transfer tx/rx_nbits:
3494 * 1. check the value matches one of single, dual and quad
3495 * 2. check tx/rx_nbits match the mode in spi_device
3498 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3499 xfer->tx_nbits != SPI_NBITS_DUAL &&
3500 xfer->tx_nbits != SPI_NBITS_QUAD)
3502 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3503 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3505 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3506 !(spi->mode & SPI_TX_QUAD))
3509 /* check transfer rx_nbits */
3511 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3512 xfer->rx_nbits != SPI_NBITS_DUAL &&
3513 xfer->rx_nbits != SPI_NBITS_QUAD)
3515 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3516 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3518 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3519 !(spi->mode & SPI_RX_QUAD))
3523 if (_spi_xfer_word_delay_update(xfer, spi))
3527 message->status = -EINPROGRESS;
3532 static int __spi_async(struct spi_device *spi, struct spi_message *message)
3534 struct spi_controller *ctlr = spi->controller;
3535 struct spi_transfer *xfer;
3538 * Some controllers do not support doing regular SPI transfers. Return
3539 * ENOTSUPP when this is the case.
3541 if (!ctlr->transfer)
3546 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
3547 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3549 trace_spi_message_submit(message);
3551 if (!ctlr->ptp_sts_supported) {
3552 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3553 xfer->ptp_sts_word_pre = 0;
3554 ptp_read_system_prets(xfer->ptp_sts);
3558 return ctlr->transfer(spi, message);
3562 * spi_async - asynchronous SPI transfer
3563 * @spi: device with which data will be exchanged
3564 * @message: describes the data transfers, including completion callback
3565 * Context: any (irqs may be blocked, etc)
3567 * This call may be used in_irq and other contexts which can't sleep,
3568 * as well as from task contexts which can sleep.
3570 * The completion callback is invoked in a context which can't sleep.
3571 * Before that invocation, the value of message->status is undefined.
3572 * When the callback is issued, message->status holds either zero (to
3573 * indicate complete success) or a negative error code. After that
3574 * callback returns, the driver which issued the transfer request may
3575 * deallocate the associated memory; it's no longer in use by any SPI
3576 * core or controller driver code.
3578 * Note that although all messages to a spi_device are handled in
3579 * FIFO order, messages may go to different devices in other orders.
3580 * Some device might be higher priority, or have various "hard" access
3581 * time requirements, for example.
3583 * On detection of any fault during the transfer, processing of
3584 * the entire message is aborted, and the device is deselected.
3585 * Until returning from the associated message completion callback,
3586 * no other spi_message queued to that device will be processed.
3587 * (This rule applies equally to all the synchronous transfer calls,
3588 * which are wrappers around this core asynchronous primitive.)
3590 * Return: zero on success, else a negative error code.
3592 int spi_async(struct spi_device *spi, struct spi_message *message)
3594 struct spi_controller *ctlr = spi->controller;
3596 unsigned long flags;
3598 ret = __spi_validate(spi, message);
3602 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3604 if (ctlr->bus_lock_flag)
3607 ret = __spi_async(spi, message);
3609 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3613 EXPORT_SYMBOL_GPL(spi_async);
3616 * spi_async_locked - version of spi_async with exclusive bus usage
3617 * @spi: device with which data will be exchanged
3618 * @message: describes the data transfers, including completion callback
3619 * Context: any (irqs may be blocked, etc)
3621 * This call may be used in_irq and other contexts which can't sleep,
3622 * as well as from task contexts which can sleep.
3624 * The completion callback is invoked in a context which can't sleep.
3625 * Before that invocation, the value of message->status is undefined.
3626 * When the callback is issued, message->status holds either zero (to
3627 * indicate complete success) or a negative error code. After that
3628 * callback returns, the driver which issued the transfer request may
3629 * deallocate the associated memory; it's no longer in use by any SPI
3630 * core or controller driver code.
3632 * Note that although all messages to a spi_device are handled in
3633 * FIFO order, messages may go to different devices in other orders.
3634 * Some device might be higher priority, or have various "hard" access
3635 * time requirements, for example.
3637 * On detection of any fault during the transfer, processing of
3638 * the entire message is aborted, and the device is deselected.
3639 * Until returning from the associated message completion callback,
3640 * no other spi_message queued to that device will be processed.
3641 * (This rule applies equally to all the synchronous transfer calls,
3642 * which are wrappers around this core asynchronous primitive.)
3644 * Return: zero on success, else a negative error code.
3646 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3648 struct spi_controller *ctlr = spi->controller;
3650 unsigned long flags;
3652 ret = __spi_validate(spi, message);
3656 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3658 ret = __spi_async(spi, message);
3660 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3665 EXPORT_SYMBOL_GPL(spi_async_locked);
3667 /*-------------------------------------------------------------------------*/
3669 /* Utility methods for SPI protocol drivers, layered on
3670 * top of the core. Some other utility methods are defined as
3674 static void spi_complete(void *arg)
3679 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3681 DECLARE_COMPLETION_ONSTACK(done);
3683 struct spi_controller *ctlr = spi->controller;
3684 unsigned long flags;
3686 status = __spi_validate(spi, message);
3690 message->complete = spi_complete;
3691 message->context = &done;
3694 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3695 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3697 /* If we're not using the legacy transfer method then we will
3698 * try to transfer in the calling context so special case.
3699 * This code would be less tricky if we could remove the
3700 * support for driver implemented message queues.
3702 if (ctlr->transfer == spi_queued_transfer) {
3703 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3705 trace_spi_message_submit(message);
3707 status = __spi_queued_transfer(spi, message, false);
3709 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3711 status = spi_async_locked(spi, message);
3715 /* Push out the messages in the calling context if we
3718 if (ctlr->transfer == spi_queued_transfer) {
3719 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3720 spi_sync_immediate);
3721 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3722 spi_sync_immediate);
3723 __spi_pump_messages(ctlr, false);
3726 wait_for_completion(&done);
3727 status = message->status;
3729 message->context = NULL;
3734 * spi_sync - blocking/synchronous SPI data transfers
3735 * @spi: device with which data will be exchanged
3736 * @message: describes the data transfers
3737 * Context: can sleep
3739 * This call may only be used from a context that may sleep. The sleep
3740 * is non-interruptible, and has no timeout. Low-overhead controller
3741 * drivers may DMA directly into and out of the message buffers.
3743 * Note that the SPI device's chip select is active during the message,
3744 * and then is normally disabled between messages. Drivers for some
3745 * frequently-used devices may want to minimize costs of selecting a chip,
3746 * by leaving it selected in anticipation that the next message will go
3747 * to the same chip. (That may increase power usage.)
3749 * Also, the caller is guaranteeing that the memory associated with the
3750 * message will not be freed before this call returns.
3752 * Return: zero on success, else a negative error code.
3754 int spi_sync(struct spi_device *spi, struct spi_message *message)
3758 mutex_lock(&spi->controller->bus_lock_mutex);
3759 ret = __spi_sync(spi, message);
3760 mutex_unlock(&spi->controller->bus_lock_mutex);
3764 EXPORT_SYMBOL_GPL(spi_sync);
3767 * spi_sync_locked - version of spi_sync with exclusive bus usage
3768 * @spi: device with which data will be exchanged
3769 * @message: describes the data transfers
3770 * Context: can sleep
3772 * This call may only be used from a context that may sleep. The sleep
3773 * is non-interruptible, and has no timeout. Low-overhead controller
3774 * drivers may DMA directly into and out of the message buffers.
3776 * This call should be used by drivers that require exclusive access to the
3777 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3778 * be released by a spi_bus_unlock call when the exclusive access is over.
3780 * Return: zero on success, else a negative error code.
3782 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3784 return __spi_sync(spi, message);
3786 EXPORT_SYMBOL_GPL(spi_sync_locked);
3789 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3790 * @ctlr: SPI bus master that should be locked for exclusive bus access
3791 * Context: can sleep
3793 * This call may only be used from a context that may sleep. The sleep
3794 * is non-interruptible, and has no timeout.
3796 * This call should be used by drivers that require exclusive access to the
3797 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3798 * exclusive access is over. Data transfer must be done by spi_sync_locked
3799 * and spi_async_locked calls when the SPI bus lock is held.
3801 * Return: always zero.
3803 int spi_bus_lock(struct spi_controller *ctlr)
3805 unsigned long flags;
3807 mutex_lock(&ctlr->bus_lock_mutex);
3809 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3810 ctlr->bus_lock_flag = 1;
3811 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3813 /* mutex remains locked until spi_bus_unlock is called */
3817 EXPORT_SYMBOL_GPL(spi_bus_lock);
3820 * spi_bus_unlock - release the lock for exclusive SPI bus usage
3821 * @ctlr: SPI bus master that was 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 releases an SPI bus lock previously obtained by an spi_bus_lock
3830 * Return: always zero.
3832 int spi_bus_unlock(struct spi_controller *ctlr)
3834 ctlr->bus_lock_flag = 0;
3836 mutex_unlock(&ctlr->bus_lock_mutex);
3840 EXPORT_SYMBOL_GPL(spi_bus_unlock);
3842 /* portable code must never pass more than 32 bytes */
3843 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3848 * spi_write_then_read - SPI synchronous write followed by read
3849 * @spi: device with which data will be exchanged
3850 * @txbuf: data to be written (need not be dma-safe)
3851 * @n_tx: size of txbuf, in bytes
3852 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3853 * @n_rx: size of rxbuf, in bytes
3854 * Context: can sleep
3856 * This performs a half duplex MicroWire style transaction with the
3857 * device, sending txbuf and then reading rxbuf. The return value
3858 * is zero for success, else a negative errno status code.
3859 * This call may only be used from a context that may sleep.
3861 * Parameters to this routine are always copied using a small buffer.
3862 * Performance-sensitive or bulk transfer code should instead use
3863 * spi_{async,sync}() calls with dma-safe buffers.
3865 * Return: zero on success, else a negative error code.
3867 int spi_write_then_read(struct spi_device *spi,
3868 const void *txbuf, unsigned n_tx,
3869 void *rxbuf, unsigned n_rx)
3871 static DEFINE_MUTEX(lock);
3874 struct spi_message message;
3875 struct spi_transfer x[2];
3878 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3879 * copying here, (as a pure convenience thing), but we can
3880 * keep heap costs out of the hot path unless someone else is
3881 * using the pre-allocated buffer or the transfer is too large.
3883 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
3884 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3885 GFP_KERNEL | GFP_DMA);
3892 spi_message_init(&message);
3893 memset(x, 0, sizeof(x));
3896 spi_message_add_tail(&x[0], &message);
3900 spi_message_add_tail(&x[1], &message);
3903 memcpy(local_buf, txbuf, n_tx);
3904 x[0].tx_buf = local_buf;
3905 x[1].rx_buf = local_buf + n_tx;
3908 status = spi_sync(spi, &message);
3910 memcpy(rxbuf, x[1].rx_buf, n_rx);
3912 if (x[0].tx_buf == buf)
3913 mutex_unlock(&lock);
3919 EXPORT_SYMBOL_GPL(spi_write_then_read);
3921 /*-------------------------------------------------------------------------*/
3923 #if IS_ENABLED(CONFIG_OF)
3924 /* must call put_device() when done with returned spi_device device */
3925 struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3927 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
3929 return dev ? to_spi_device(dev) : NULL;
3931 EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
3932 #endif /* IS_ENABLED(CONFIG_OF) */
3934 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
3935 /* the spi controllers are not using spi_bus, so we find it with another way */
3936 static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
3940 dev = class_find_device_by_of_node(&spi_master_class, node);
3941 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3942 dev = class_find_device_by_of_node(&spi_slave_class, node);
3946 /* reference got in class_find_device */
3947 return container_of(dev, struct spi_controller, dev);
3950 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3953 struct of_reconfig_data *rd = arg;
3954 struct spi_controller *ctlr;
3955 struct spi_device *spi;
3957 switch (of_reconfig_get_state_change(action, arg)) {
3958 case OF_RECONFIG_CHANGE_ADD:
3959 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
3961 return NOTIFY_OK; /* not for us */
3963 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3964 put_device(&ctlr->dev);
3968 spi = of_register_spi_device(ctlr, rd->dn);
3969 put_device(&ctlr->dev);
3972 pr_err("%s: failed to create for '%pOF'\n",
3974 of_node_clear_flag(rd->dn, OF_POPULATED);
3975 return notifier_from_errno(PTR_ERR(spi));
3979 case OF_RECONFIG_CHANGE_REMOVE:
3980 /* already depopulated? */
3981 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3984 /* find our device by node */
3985 spi = of_find_spi_device_by_node(rd->dn);
3987 return NOTIFY_OK; /* no? not meant for us */
3989 /* unregister takes one ref away */
3990 spi_unregister_device(spi);
3992 /* and put the reference of the find */
3993 put_device(&spi->dev);
4000 static struct notifier_block spi_of_notifier = {
4001 .notifier_call = of_spi_notify,
4003 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4004 extern struct notifier_block spi_of_notifier;
4005 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4007 #if IS_ENABLED(CONFIG_ACPI)
4008 static int spi_acpi_controller_match(struct device *dev, const void *data)
4010 return ACPI_COMPANION(dev->parent) == data;
4013 static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4017 dev = class_find_device(&spi_master_class, NULL, adev,
4018 spi_acpi_controller_match);
4019 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4020 dev = class_find_device(&spi_slave_class, NULL, adev,
4021 spi_acpi_controller_match);
4025 return container_of(dev, struct spi_controller, dev);
4028 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4032 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4033 return to_spi_device(dev);
4036 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4039 struct acpi_device *adev = arg;
4040 struct spi_controller *ctlr;
4041 struct spi_device *spi;
4044 case ACPI_RECONFIG_DEVICE_ADD:
4045 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
4049 acpi_register_spi_device(ctlr, adev);
4050 put_device(&ctlr->dev);
4052 case ACPI_RECONFIG_DEVICE_REMOVE:
4053 if (!acpi_device_enumerated(adev))
4056 spi = acpi_spi_find_device_by_adev(adev);
4060 spi_unregister_device(spi);
4061 put_device(&spi->dev);
4068 static struct notifier_block spi_acpi_notifier = {
4069 .notifier_call = acpi_spi_notify,
4072 extern struct notifier_block spi_acpi_notifier;
4075 static int __init spi_init(void)
4079 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4085 status = bus_register(&spi_bus_type);
4089 status = class_register(&spi_master_class);
4093 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4094 status = class_register(&spi_slave_class);
4099 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4100 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4101 if (IS_ENABLED(CONFIG_ACPI))
4102 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4107 class_unregister(&spi_master_class);
4109 bus_unregister(&spi_bus_type);
4117 /* board_info is normally registered in arch_initcall(),
4118 * but even essential drivers wait till later
4120 * REVISIT only boardinfo really needs static linking. the rest (device and
4121 * driver registration) _could_ be dynamically linked (modular) ... costs
4122 * include needing to have boardinfo data structures be much more public.
4124 postcore_initcall(spi_init);