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/acpi.h>
8 #include <linux/cache.h>
9 #include <linux/clk/clk-conf.h>
10 #include <linux/delay.h>
11 #include <linux/device.h>
12 #include <linux/dmaengine.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/export.h>
15 #include <linux/gpio/consumer.h>
16 #include <linux/highmem.h>
17 #include <linux/idr.h>
18 #include <linux/init.h>
19 #include <linux/ioport.h>
20 #include <linux/kernel.h>
21 #include <linux/kthread.h>
22 #include <linux/mod_devicetable.h>
23 #include <linux/mutex.h>
24 #include <linux/of_device.h>
25 #include <linux/of_irq.h>
26 #include <linux/percpu.h>
27 #include <linux/platform_data/x86/apple.h>
28 #include <linux/pm_domain.h>
29 #include <linux/pm_runtime.h>
30 #include <linux/property.h>
31 #include <linux/ptp_clock_kernel.h>
32 #include <linux/sched/rt.h>
33 #include <linux/slab.h>
34 #include <linux/spi/spi.h>
35 #include <linux/spi/spi-mem.h>
36 #include <uapi/linux/sched/types.h>
38 #define CREATE_TRACE_POINTS
39 #include <trace/events/spi.h>
40 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start);
41 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop);
43 #include "internals.h"
45 static DEFINE_IDR(spi_master_idr);
47 static void spidev_release(struct device *dev)
49 struct spi_device *spi = to_spi_device(dev);
51 spi_controller_put(spi->controller);
52 kfree(spi->driver_override);
53 free_percpu(spi->pcpu_statistics);
58 modalias_show(struct device *dev, struct device_attribute *a, char *buf)
60 const struct spi_device *spi = to_spi_device(dev);
63 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
67 return sysfs_emit(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
69 static DEVICE_ATTR_RO(modalias);
71 static ssize_t driver_override_store(struct device *dev,
72 struct device_attribute *a,
73 const char *buf, size_t count)
75 struct spi_device *spi = to_spi_device(dev);
78 ret = driver_set_override(dev, &spi->driver_override, buf, count);
85 static ssize_t driver_override_show(struct device *dev,
86 struct device_attribute *a, char *buf)
88 const struct spi_device *spi = to_spi_device(dev);
92 len = sysfs_emit(buf, "%s\n", spi->driver_override ? : "");
96 static DEVICE_ATTR_RW(driver_override);
98 static struct spi_statistics __percpu *spi_alloc_pcpu_stats(struct device *dev)
100 struct spi_statistics __percpu *pcpu_stats;
103 pcpu_stats = devm_alloc_percpu(dev, struct spi_statistics);
105 pcpu_stats = alloc_percpu_gfp(struct spi_statistics, GFP_KERNEL);
110 for_each_possible_cpu(cpu) {
111 struct spi_statistics *stat;
113 stat = per_cpu_ptr(pcpu_stats, cpu);
114 u64_stats_init(&stat->syncp);
120 static ssize_t spi_emit_pcpu_stats(struct spi_statistics __percpu *stat,
121 char *buf, size_t offset)
126 for_each_possible_cpu(i) {
127 const struct spi_statistics *pcpu_stats;
132 pcpu_stats = per_cpu_ptr(stat, i);
133 field = (void *)pcpu_stats + offset;
135 start = u64_stats_fetch_begin(&pcpu_stats->syncp);
136 inc = u64_stats_read(field);
137 } while (u64_stats_fetch_retry(&pcpu_stats->syncp, start));
140 return sysfs_emit(buf, "%llu\n", val);
143 #define SPI_STATISTICS_ATTRS(field, file) \
144 static ssize_t spi_controller_##field##_show(struct device *dev, \
145 struct device_attribute *attr, \
148 struct spi_controller *ctlr = container_of(dev, \
149 struct spi_controller, dev); \
150 return spi_statistics_##field##_show(ctlr->pcpu_statistics, buf); \
152 static struct device_attribute dev_attr_spi_controller_##field = { \
153 .attr = { .name = file, .mode = 0444 }, \
154 .show = spi_controller_##field##_show, \
156 static ssize_t spi_device_##field##_show(struct device *dev, \
157 struct device_attribute *attr, \
160 struct spi_device *spi = to_spi_device(dev); \
161 return spi_statistics_##field##_show(spi->pcpu_statistics, buf); \
163 static struct device_attribute dev_attr_spi_device_##field = { \
164 .attr = { .name = file, .mode = 0444 }, \
165 .show = spi_device_##field##_show, \
168 #define SPI_STATISTICS_SHOW_NAME(name, file, field) \
169 static ssize_t spi_statistics_##name##_show(struct spi_statistics __percpu *stat, \
172 return spi_emit_pcpu_stats(stat, buf, \
173 offsetof(struct spi_statistics, field)); \
175 SPI_STATISTICS_ATTRS(name, file)
177 #define SPI_STATISTICS_SHOW(field) \
178 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
181 SPI_STATISTICS_SHOW(messages);
182 SPI_STATISTICS_SHOW(transfers);
183 SPI_STATISTICS_SHOW(errors);
184 SPI_STATISTICS_SHOW(timedout);
186 SPI_STATISTICS_SHOW(spi_sync);
187 SPI_STATISTICS_SHOW(spi_sync_immediate);
188 SPI_STATISTICS_SHOW(spi_async);
190 SPI_STATISTICS_SHOW(bytes);
191 SPI_STATISTICS_SHOW(bytes_rx);
192 SPI_STATISTICS_SHOW(bytes_tx);
194 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
195 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
196 "transfer_bytes_histo_" number, \
197 transfer_bytes_histo[index])
198 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
199 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
200 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
201 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
202 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
203 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
204 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
205 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
206 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
207 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
208 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
209 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
210 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
211 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
212 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
213 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
214 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
216 SPI_STATISTICS_SHOW(transfers_split_maxsize);
218 static struct attribute *spi_dev_attrs[] = {
219 &dev_attr_modalias.attr,
220 &dev_attr_driver_override.attr,
224 static const struct attribute_group spi_dev_group = {
225 .attrs = spi_dev_attrs,
228 static struct attribute *spi_device_statistics_attrs[] = {
229 &dev_attr_spi_device_messages.attr,
230 &dev_attr_spi_device_transfers.attr,
231 &dev_attr_spi_device_errors.attr,
232 &dev_attr_spi_device_timedout.attr,
233 &dev_attr_spi_device_spi_sync.attr,
234 &dev_attr_spi_device_spi_sync_immediate.attr,
235 &dev_attr_spi_device_spi_async.attr,
236 &dev_attr_spi_device_bytes.attr,
237 &dev_attr_spi_device_bytes_rx.attr,
238 &dev_attr_spi_device_bytes_tx.attr,
239 &dev_attr_spi_device_transfer_bytes_histo0.attr,
240 &dev_attr_spi_device_transfer_bytes_histo1.attr,
241 &dev_attr_spi_device_transfer_bytes_histo2.attr,
242 &dev_attr_spi_device_transfer_bytes_histo3.attr,
243 &dev_attr_spi_device_transfer_bytes_histo4.attr,
244 &dev_attr_spi_device_transfer_bytes_histo5.attr,
245 &dev_attr_spi_device_transfer_bytes_histo6.attr,
246 &dev_attr_spi_device_transfer_bytes_histo7.attr,
247 &dev_attr_spi_device_transfer_bytes_histo8.attr,
248 &dev_attr_spi_device_transfer_bytes_histo9.attr,
249 &dev_attr_spi_device_transfer_bytes_histo10.attr,
250 &dev_attr_spi_device_transfer_bytes_histo11.attr,
251 &dev_attr_spi_device_transfer_bytes_histo12.attr,
252 &dev_attr_spi_device_transfer_bytes_histo13.attr,
253 &dev_attr_spi_device_transfer_bytes_histo14.attr,
254 &dev_attr_spi_device_transfer_bytes_histo15.attr,
255 &dev_attr_spi_device_transfer_bytes_histo16.attr,
256 &dev_attr_spi_device_transfers_split_maxsize.attr,
260 static const struct attribute_group spi_device_statistics_group = {
261 .name = "statistics",
262 .attrs = spi_device_statistics_attrs,
265 static const struct attribute_group *spi_dev_groups[] = {
267 &spi_device_statistics_group,
271 static struct attribute *spi_controller_statistics_attrs[] = {
272 &dev_attr_spi_controller_messages.attr,
273 &dev_attr_spi_controller_transfers.attr,
274 &dev_attr_spi_controller_errors.attr,
275 &dev_attr_spi_controller_timedout.attr,
276 &dev_attr_spi_controller_spi_sync.attr,
277 &dev_attr_spi_controller_spi_sync_immediate.attr,
278 &dev_attr_spi_controller_spi_async.attr,
279 &dev_attr_spi_controller_bytes.attr,
280 &dev_attr_spi_controller_bytes_rx.attr,
281 &dev_attr_spi_controller_bytes_tx.attr,
282 &dev_attr_spi_controller_transfer_bytes_histo0.attr,
283 &dev_attr_spi_controller_transfer_bytes_histo1.attr,
284 &dev_attr_spi_controller_transfer_bytes_histo2.attr,
285 &dev_attr_spi_controller_transfer_bytes_histo3.attr,
286 &dev_attr_spi_controller_transfer_bytes_histo4.attr,
287 &dev_attr_spi_controller_transfer_bytes_histo5.attr,
288 &dev_attr_spi_controller_transfer_bytes_histo6.attr,
289 &dev_attr_spi_controller_transfer_bytes_histo7.attr,
290 &dev_attr_spi_controller_transfer_bytes_histo8.attr,
291 &dev_attr_spi_controller_transfer_bytes_histo9.attr,
292 &dev_attr_spi_controller_transfer_bytes_histo10.attr,
293 &dev_attr_spi_controller_transfer_bytes_histo11.attr,
294 &dev_attr_spi_controller_transfer_bytes_histo12.attr,
295 &dev_attr_spi_controller_transfer_bytes_histo13.attr,
296 &dev_attr_spi_controller_transfer_bytes_histo14.attr,
297 &dev_attr_spi_controller_transfer_bytes_histo15.attr,
298 &dev_attr_spi_controller_transfer_bytes_histo16.attr,
299 &dev_attr_spi_controller_transfers_split_maxsize.attr,
303 static const struct attribute_group spi_controller_statistics_group = {
304 .name = "statistics",
305 .attrs = spi_controller_statistics_attrs,
308 static const struct attribute_group *spi_master_groups[] = {
309 &spi_controller_statistics_group,
313 static void spi_statistics_add_transfer_stats(struct spi_statistics __percpu *pcpu_stats,
314 struct spi_transfer *xfer,
315 struct spi_controller *ctlr)
317 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
318 struct spi_statistics *stats;
324 stats = this_cpu_ptr(pcpu_stats);
325 u64_stats_update_begin(&stats->syncp);
327 u64_stats_inc(&stats->transfers);
328 u64_stats_inc(&stats->transfer_bytes_histo[l2len]);
330 u64_stats_add(&stats->bytes, xfer->len);
331 if ((xfer->tx_buf) &&
332 (xfer->tx_buf != ctlr->dummy_tx))
333 u64_stats_add(&stats->bytes_tx, xfer->len);
334 if ((xfer->rx_buf) &&
335 (xfer->rx_buf != ctlr->dummy_rx))
336 u64_stats_add(&stats->bytes_rx, xfer->len);
338 u64_stats_update_end(&stats->syncp);
343 * modalias support makes "modprobe $MODALIAS" new-style hotplug work,
344 * and the sysfs version makes coldplug work too.
346 static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, const char *name)
348 while (id->name[0]) {
349 if (!strcmp(name, id->name))
356 const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
358 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
360 return spi_match_id(sdrv->id_table, sdev->modalias);
362 EXPORT_SYMBOL_GPL(spi_get_device_id);
364 const void *spi_get_device_match_data(const struct spi_device *sdev)
368 match = device_get_match_data(&sdev->dev);
372 return (const void *)spi_get_device_id(sdev)->driver_data;
374 EXPORT_SYMBOL_GPL(spi_get_device_match_data);
376 static int spi_match_device(struct device *dev, struct device_driver *drv)
378 const struct spi_device *spi = to_spi_device(dev);
379 const struct spi_driver *sdrv = to_spi_driver(drv);
381 /* Check override first, and if set, only use the named driver */
382 if (spi->driver_override)
383 return strcmp(spi->driver_override, drv->name) == 0;
385 /* Attempt an OF style match */
386 if (of_driver_match_device(dev, drv))
390 if (acpi_driver_match_device(dev, drv))
394 return !!spi_match_id(sdrv->id_table, spi->modalias);
396 return strcmp(spi->modalias, drv->name) == 0;
399 static int spi_uevent(const struct device *dev, struct kobj_uevent_env *env)
401 const struct spi_device *spi = to_spi_device(dev);
404 rc = acpi_device_uevent_modalias(dev, env);
408 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
411 static int spi_probe(struct device *dev)
413 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
414 struct spi_device *spi = to_spi_device(dev);
417 ret = of_clk_set_defaults(dev->of_node, false);
422 spi->irq = of_irq_get(dev->of_node, 0);
423 if (spi->irq == -EPROBE_DEFER)
424 return -EPROBE_DEFER;
429 ret = dev_pm_domain_attach(dev, true);
434 ret = sdrv->probe(spi);
436 dev_pm_domain_detach(dev, true);
442 static void spi_remove(struct device *dev)
444 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
447 sdrv->remove(to_spi_device(dev));
449 dev_pm_domain_detach(dev, true);
452 static void spi_shutdown(struct device *dev)
455 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
458 sdrv->shutdown(to_spi_device(dev));
462 struct bus_type spi_bus_type = {
464 .dev_groups = spi_dev_groups,
465 .match = spi_match_device,
466 .uevent = spi_uevent,
468 .remove = spi_remove,
469 .shutdown = spi_shutdown,
471 EXPORT_SYMBOL_GPL(spi_bus_type);
474 * __spi_register_driver - register a SPI driver
475 * @owner: owner module of the driver to register
476 * @sdrv: the driver to register
479 * Return: zero on success, else a negative error code.
481 int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
483 sdrv->driver.owner = owner;
484 sdrv->driver.bus = &spi_bus_type;
487 * For Really Good Reasons we use spi: modaliases not of:
488 * modaliases for DT so module autoloading won't work if we
489 * don't have a spi_device_id as well as a compatible string.
491 if (sdrv->driver.of_match_table) {
492 const struct of_device_id *of_id;
494 for (of_id = sdrv->driver.of_match_table; of_id->compatible[0];
498 /* Strip off any vendor prefix */
499 of_name = strnchr(of_id->compatible,
500 sizeof(of_id->compatible), ',');
504 of_name = of_id->compatible;
506 if (sdrv->id_table) {
507 const struct spi_device_id *spi_id;
509 spi_id = spi_match_id(sdrv->id_table, of_name);
513 if (strcmp(sdrv->driver.name, of_name) == 0)
517 pr_warn("SPI driver %s has no spi_device_id for %s\n",
518 sdrv->driver.name, of_id->compatible);
522 return driver_register(&sdrv->driver);
524 EXPORT_SYMBOL_GPL(__spi_register_driver);
526 /*-------------------------------------------------------------------------*/
529 * SPI devices should normally not be created by SPI device drivers; that
530 * would make them board-specific. Similarly with SPI controller drivers.
531 * Device registration normally goes into like arch/.../mach.../board-YYY.c
532 * with other readonly (flashable) information about mainboard devices.
536 struct list_head list;
537 struct spi_board_info board_info;
540 static LIST_HEAD(board_list);
541 static LIST_HEAD(spi_controller_list);
544 * Used to protect add/del operation for board_info list and
545 * spi_controller list, and their matching process also used
546 * to protect object of type struct idr.
548 static DEFINE_MUTEX(board_lock);
551 * spi_alloc_device - Allocate a new SPI device
552 * @ctlr: Controller to which device is connected
555 * Allows a driver to allocate and initialize a spi_device without
556 * registering it immediately. This allows a driver to directly
557 * fill the spi_device with device parameters before calling
558 * spi_add_device() on it.
560 * Caller is responsible to call spi_add_device() on the returned
561 * spi_device structure to add it to the SPI controller. If the caller
562 * needs to discard the spi_device without adding it, then it should
563 * call spi_dev_put() on it.
565 * Return: a pointer to the new device, or NULL.
567 struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
569 struct spi_device *spi;
571 if (!spi_controller_get(ctlr))
574 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
576 spi_controller_put(ctlr);
580 spi->pcpu_statistics = spi_alloc_pcpu_stats(NULL);
581 if (!spi->pcpu_statistics) {
583 spi_controller_put(ctlr);
587 spi->master = spi->controller = ctlr;
588 spi->dev.parent = &ctlr->dev;
589 spi->dev.bus = &spi_bus_type;
590 spi->dev.release = spidev_release;
591 spi->mode = ctlr->buswidth_override_bits;
593 device_initialize(&spi->dev);
596 EXPORT_SYMBOL_GPL(spi_alloc_device);
598 static void spi_dev_set_name(struct spi_device *spi)
600 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
603 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
607 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
608 spi_get_chipselect(spi, 0));
611 static int spi_dev_check(struct device *dev, void *data)
613 struct spi_device *spi = to_spi_device(dev);
614 struct spi_device *new_spi = data;
618 if (spi->controller == new_spi->controller) {
619 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
620 cs = spi_get_chipselect(spi, idx);
621 for (nw_idx = 0; nw_idx < SPI_CS_CNT_MAX; nw_idx++) {
622 cs_nw = spi_get_chipselect(new_spi, nw_idx);
623 if (cs != 0xFF && cs_nw != 0xFF && cs == cs_nw) {
624 dev_err(dev, "chipselect %d already in use\n", cs_nw);
633 static void spi_cleanup(struct spi_device *spi)
635 if (spi->controller->cleanup)
636 spi->controller->cleanup(spi);
639 static int __spi_add_device(struct spi_device *spi)
641 struct spi_controller *ctlr = spi->controller;
642 struct device *dev = ctlr->dev.parent;
643 int status, idx, nw_idx;
646 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
647 /* Chipselects are numbered 0..max; validate. */
648 cs = spi_get_chipselect(spi, idx);
649 if (cs != 0xFF && cs >= ctlr->num_chipselect) {
650 dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, idx),
651 ctlr->num_chipselect);
657 * Make sure that multiple logical CS doesn't map to the same physical CS.
658 * For example, spi->chip_select[0] != spi->chip_select[1] and so on.
660 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
661 cs = spi_get_chipselect(spi, idx);
662 for (nw_idx = idx + 1; nw_idx < SPI_CS_CNT_MAX; nw_idx++) {
663 nw_cs = spi_get_chipselect(spi, nw_idx);
664 if (cs != 0xFF && nw_cs != 0xFF && cs == nw_cs) {
665 dev_err(dev, "chipselect %d already in use\n", nw_cs);
671 /* Set the bus ID string */
672 spi_dev_set_name(spi);
675 * We need to make sure there's no other device with this
676 * chipselect **BEFORE** we call setup(), else we'll trash
679 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
683 /* Controller may unregister concurrently */
684 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
685 !device_is_registered(&ctlr->dev)) {
689 if (ctlr->cs_gpiods) {
692 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
693 cs = spi_get_chipselect(spi, idx);
695 spi_set_csgpiod(spi, idx, ctlr->cs_gpiods[cs]);
700 * Drivers may modify this initial i/o setup, but will
701 * normally rely on the device being setup. Devices
702 * using SPI_CS_HIGH can't coexist well otherwise...
704 status = spi_setup(spi);
706 dev_err(dev, "can't setup %s, status %d\n",
707 dev_name(&spi->dev), status);
711 /* Device may be bound to an active driver when this returns */
712 status = device_add(&spi->dev);
714 dev_err(dev, "can't add %s, status %d\n",
715 dev_name(&spi->dev), status);
718 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
725 * spi_add_device - Add spi_device allocated with spi_alloc_device
726 * @spi: spi_device to register
728 * Companion function to spi_alloc_device. Devices allocated with
729 * spi_alloc_device can be added onto the SPI bus with this function.
731 * Return: 0 on success; negative errno on failure
733 int spi_add_device(struct spi_device *spi)
735 struct spi_controller *ctlr = spi->controller;
738 /* Set the bus ID string */
739 spi_dev_set_name(spi);
741 mutex_lock(&ctlr->add_lock);
742 status = __spi_add_device(spi);
743 mutex_unlock(&ctlr->add_lock);
746 EXPORT_SYMBOL_GPL(spi_add_device);
749 * spi_new_device - instantiate one new SPI device
750 * @ctlr: Controller to which device is connected
751 * @chip: Describes the SPI device
754 * On typical mainboards, this is purely internal; and it's not needed
755 * after board init creates the hard-wired devices. Some development
756 * platforms may not be able to use spi_register_board_info though, and
757 * this is exported so that for example a USB or parport based adapter
758 * driver could add devices (which it would learn about out-of-band).
760 * Return: the new device, or NULL.
762 struct spi_device *spi_new_device(struct spi_controller *ctlr,
763 struct spi_board_info *chip)
765 struct spi_device *proxy;
770 * NOTE: caller did any chip->bus_num checks necessary.
772 * Also, unless we change the return value convention to use
773 * error-or-pointer (not NULL-or-pointer), troubleshootability
774 * suggests syslogged diagnostics are best here (ugh).
777 proxy = spi_alloc_device(ctlr);
781 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
784 * Zero(0) is a valid physical CS value and can be located at any
785 * logical CS in the spi->chip_select[]. If all the physical CS
786 * are initialized to 0 then It would be difficult to differentiate
787 * between a valid physical CS 0 & an unused logical CS whose physical
788 * CS can be 0. As a solution to this issue initialize all the CS to 0xFF.
789 * Now all the unused logical CS will have 0xFF physical CS value & can be
790 * ignore while performing physical CS validity checks.
792 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
793 spi_set_chipselect(proxy, idx, 0xFF);
795 spi_set_chipselect(proxy, 0, chip->chip_select);
796 proxy->max_speed_hz = chip->max_speed_hz;
797 proxy->mode = chip->mode;
798 proxy->irq = chip->irq;
799 strscpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
800 proxy->dev.platform_data = (void *) chip->platform_data;
801 proxy->controller_data = chip->controller_data;
802 proxy->controller_state = NULL;
804 * spi->chip_select[i] gives the corresponding physical CS for logical CS i
805 * logical CS number is represented by setting the ith bit in spi->cs_index_mask
806 * So, for example, if spi->cs_index_mask = 0x01 then logical CS number is 0 and
807 * spi->chip_select[0] will give the physical CS.
808 * By default spi->chip_select[0] will hold the physical CS number so, set
809 * spi->cs_index_mask as 0x01.
811 proxy->cs_index_mask = 0x01;
814 status = device_add_software_node(&proxy->dev, chip->swnode);
816 dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n",
817 chip->modalias, status);
822 status = spi_add_device(proxy);
829 device_remove_software_node(&proxy->dev);
833 EXPORT_SYMBOL_GPL(spi_new_device);
836 * spi_unregister_device - unregister a single SPI device
837 * @spi: spi_device to unregister
839 * Start making the passed SPI device vanish. Normally this would be handled
840 * by spi_unregister_controller().
842 void spi_unregister_device(struct spi_device *spi)
847 if (spi->dev.of_node) {
848 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
849 of_node_put(spi->dev.of_node);
851 if (ACPI_COMPANION(&spi->dev))
852 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
853 device_remove_software_node(&spi->dev);
854 device_del(&spi->dev);
856 put_device(&spi->dev);
858 EXPORT_SYMBOL_GPL(spi_unregister_device);
860 static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
861 struct spi_board_info *bi)
863 struct spi_device *dev;
865 if (ctlr->bus_num != bi->bus_num)
868 dev = spi_new_device(ctlr, bi);
870 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
875 * spi_register_board_info - register SPI devices for a given board
876 * @info: array of chip descriptors
877 * @n: how many descriptors are provided
880 * Board-specific early init code calls this (probably during arch_initcall)
881 * with segments of the SPI device table. Any device nodes are created later,
882 * after the relevant parent SPI controller (bus_num) is defined. We keep
883 * this table of devices forever, so that reloading a controller driver will
884 * not make Linux forget about these hard-wired devices.
886 * Other code can also call this, e.g. a particular add-on board might provide
887 * SPI devices through its expansion connector, so code initializing that board
888 * would naturally declare its SPI devices.
890 * The board info passed can safely be __initdata ... but be careful of
891 * any embedded pointers (platform_data, etc), they're copied as-is.
893 * Return: zero on success, else a negative error code.
895 int spi_register_board_info(struct spi_board_info const *info, unsigned n)
897 struct boardinfo *bi;
903 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
907 for (i = 0; i < n; i++, bi++, info++) {
908 struct spi_controller *ctlr;
910 memcpy(&bi->board_info, info, sizeof(*info));
912 mutex_lock(&board_lock);
913 list_add_tail(&bi->list, &board_list);
914 list_for_each_entry(ctlr, &spi_controller_list, list)
915 spi_match_controller_to_boardinfo(ctlr,
917 mutex_unlock(&board_lock);
923 /*-------------------------------------------------------------------------*/
925 /* Core methods for SPI resource management */
928 * spi_res_alloc - allocate a spi resource that is life-cycle managed
929 * during the processing of a spi_message while using
931 * @spi: the SPI device for which we allocate memory
932 * @release: the release code to execute for this resource
933 * @size: size to alloc and return
934 * @gfp: GFP allocation flags
936 * Return: the pointer to the allocated data
938 * This may get enhanced in the future to allocate from a memory pool
939 * of the @spi_device or @spi_controller to avoid repeated allocations.
941 static void *spi_res_alloc(struct spi_device *spi, spi_res_release_t release,
942 size_t size, gfp_t gfp)
944 struct spi_res *sres;
946 sres = kzalloc(sizeof(*sres) + size, gfp);
950 INIT_LIST_HEAD(&sres->entry);
951 sres->release = release;
957 * spi_res_free - free an SPI resource
958 * @res: pointer to the custom data of a resource
960 static void spi_res_free(void *res)
962 struct spi_res *sres = container_of(res, struct spi_res, data);
967 WARN_ON(!list_empty(&sres->entry));
972 * spi_res_add - add a spi_res to the spi_message
973 * @message: the SPI message
974 * @res: the spi_resource
976 static void spi_res_add(struct spi_message *message, void *res)
978 struct spi_res *sres = container_of(res, struct spi_res, data);
980 WARN_ON(!list_empty(&sres->entry));
981 list_add_tail(&sres->entry, &message->resources);
985 * spi_res_release - release all SPI resources for this message
986 * @ctlr: the @spi_controller
987 * @message: the @spi_message
989 static void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
991 struct spi_res *res, *tmp;
993 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
995 res->release(ctlr, message, res->data);
997 list_del(&res->entry);
1003 /*-------------------------------------------------------------------------*/
1004 static inline bool spi_is_last_cs(struct spi_device *spi)
1009 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
1010 if ((spi->cs_index_mask >> idx) & 0x01) {
1011 if (spi->controller->last_cs[idx] == spi_get_chipselect(spi, idx))
1019 static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
1021 bool activate = enable;
1025 * Avoid calling into the driver (or doing delays) if the chip select
1026 * isn't actually changing from the last time this was called.
1028 if (!force && ((enable && spi->controller->last_cs_index_mask == spi->cs_index_mask &&
1029 spi_is_last_cs(spi)) ||
1030 (!enable && spi->controller->last_cs_index_mask == spi->cs_index_mask &&
1031 !spi_is_last_cs(spi))) &&
1032 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
1035 trace_spi_set_cs(spi, activate);
1037 spi->controller->last_cs_index_mask = spi->cs_index_mask;
1038 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
1039 spi->controller->last_cs[idx] = enable ? spi_get_chipselect(spi, 0) : -1;
1040 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
1042 if (spi->mode & SPI_CS_HIGH)
1046 * Handle chip select delays for GPIO based CS or controllers without
1047 * programmable chip select timing.
1049 if ((spi_is_csgpiod(spi) || !spi->controller->set_cs_timing) && !activate)
1050 spi_delay_exec(&spi->cs_hold, NULL);
1052 if (spi_is_csgpiod(spi)) {
1053 if (!(spi->mode & SPI_NO_CS)) {
1055 * Historically ACPI has no means of the GPIO polarity and
1056 * thus the SPISerialBus() resource defines it on the per-chip
1057 * basis. In order to avoid a chain of negations, the GPIO
1058 * polarity is considered being Active High. Even for the cases
1059 * when _DSD() is involved (in the updated versions of ACPI)
1060 * the GPIO CS polarity must be defined Active High to avoid
1061 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
1064 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
1065 if (((spi->cs_index_mask >> idx) & 0x01) &&
1066 spi_get_csgpiod(spi, idx)) {
1067 if (has_acpi_companion(&spi->dev))
1068 gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx),
1071 /* Polarity handled by GPIO library */
1072 gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx),
1076 spi_delay_exec(&spi->cs_setup, NULL);
1078 spi_delay_exec(&spi->cs_inactive, NULL);
1082 /* Some SPI masters need both GPIO CS & slave_select */
1083 if ((spi->controller->flags & SPI_CONTROLLER_GPIO_SS) &&
1084 spi->controller->set_cs)
1085 spi->controller->set_cs(spi, !enable);
1086 } else if (spi->controller->set_cs) {
1087 spi->controller->set_cs(spi, !enable);
1090 if (spi_is_csgpiod(spi) || !spi->controller->set_cs_timing) {
1092 spi_delay_exec(&spi->cs_setup, NULL);
1094 spi_delay_exec(&spi->cs_inactive, NULL);
1098 #ifdef CONFIG_HAS_DMA
1099 static int spi_map_buf_attrs(struct spi_controller *ctlr, struct device *dev,
1100 struct sg_table *sgt, void *buf, size_t len,
1101 enum dma_data_direction dir, unsigned long attrs)
1103 const bool vmalloced_buf = is_vmalloc_addr(buf);
1104 unsigned int max_seg_size = dma_get_max_seg_size(dev);
1105 #ifdef CONFIG_HIGHMEM
1106 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
1107 (unsigned long)buf < (PKMAP_BASE +
1108 (LAST_PKMAP * PAGE_SIZE)));
1110 const bool kmap_buf = false;
1114 struct page *vm_page;
1115 struct scatterlist *sg;
1120 if (vmalloced_buf || kmap_buf) {
1121 desc_len = min_t(unsigned long, max_seg_size, PAGE_SIZE);
1122 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
1123 } else if (virt_addr_valid(buf)) {
1124 desc_len = min_t(size_t, max_seg_size, ctlr->max_dma_len);
1125 sgs = DIV_ROUND_UP(len, desc_len);
1130 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
1135 for (i = 0; i < sgs; i++) {
1137 if (vmalloced_buf || kmap_buf) {
1139 * Next scatterlist entry size is the minimum between
1140 * the desc_len and the remaining buffer length that
1143 min = min_t(size_t, desc_len,
1145 PAGE_SIZE - offset_in_page(buf)));
1147 vm_page = vmalloc_to_page(buf);
1149 vm_page = kmap_to_page(buf);
1154 sg_set_page(sg, vm_page,
1155 min, offset_in_page(buf));
1157 min = min_t(size_t, len, desc_len);
1159 sg_set_buf(sg, sg_buf, min);
1167 ret = dma_map_sgtable(dev, sgt, dir, attrs);
1176 int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
1177 struct sg_table *sgt, void *buf, size_t len,
1178 enum dma_data_direction dir)
1180 return spi_map_buf_attrs(ctlr, dev, sgt, buf, len, dir, 0);
1183 static void spi_unmap_buf_attrs(struct spi_controller *ctlr,
1184 struct device *dev, struct sg_table *sgt,
1185 enum dma_data_direction dir,
1186 unsigned long attrs)
1188 if (sgt->orig_nents) {
1189 dma_unmap_sgtable(dev, sgt, dir, attrs);
1191 sgt->orig_nents = 0;
1196 void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
1197 struct sg_table *sgt, enum dma_data_direction dir)
1199 spi_unmap_buf_attrs(ctlr, dev, sgt, dir, 0);
1202 static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1204 struct device *tx_dev, *rx_dev;
1205 struct spi_transfer *xfer;
1212 tx_dev = ctlr->dma_tx->device->dev;
1213 else if (ctlr->dma_map_dev)
1214 tx_dev = ctlr->dma_map_dev;
1216 tx_dev = ctlr->dev.parent;
1219 rx_dev = ctlr->dma_rx->device->dev;
1220 else if (ctlr->dma_map_dev)
1221 rx_dev = ctlr->dma_map_dev;
1223 rx_dev = ctlr->dev.parent;
1225 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1226 /* The sync is done before each transfer. */
1227 unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC;
1229 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1232 if (xfer->tx_buf != NULL) {
1233 ret = spi_map_buf_attrs(ctlr, tx_dev, &xfer->tx_sg,
1234 (void *)xfer->tx_buf,
1235 xfer->len, DMA_TO_DEVICE,
1241 if (xfer->rx_buf != NULL) {
1242 ret = spi_map_buf_attrs(ctlr, rx_dev, &xfer->rx_sg,
1243 xfer->rx_buf, xfer->len,
1244 DMA_FROM_DEVICE, attrs);
1246 spi_unmap_buf_attrs(ctlr, tx_dev,
1247 &xfer->tx_sg, DMA_TO_DEVICE,
1255 ctlr->cur_rx_dma_dev = rx_dev;
1256 ctlr->cur_tx_dma_dev = tx_dev;
1257 ctlr->cur_msg_mapped = true;
1262 static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
1264 struct device *rx_dev = ctlr->cur_rx_dma_dev;
1265 struct device *tx_dev = ctlr->cur_tx_dma_dev;
1266 struct spi_transfer *xfer;
1268 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
1271 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1272 /* The sync has already been done after each transfer. */
1273 unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC;
1275 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1278 spi_unmap_buf_attrs(ctlr, rx_dev, &xfer->rx_sg,
1279 DMA_FROM_DEVICE, attrs);
1280 spi_unmap_buf_attrs(ctlr, tx_dev, &xfer->tx_sg,
1281 DMA_TO_DEVICE, attrs);
1284 ctlr->cur_msg_mapped = false;
1289 static void spi_dma_sync_for_device(struct spi_controller *ctlr,
1290 struct spi_transfer *xfer)
1292 struct device *rx_dev = ctlr->cur_rx_dma_dev;
1293 struct device *tx_dev = ctlr->cur_tx_dma_dev;
1295 if (!ctlr->cur_msg_mapped)
1298 if (xfer->tx_sg.orig_nents)
1299 dma_sync_sgtable_for_device(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1300 if (xfer->rx_sg.orig_nents)
1301 dma_sync_sgtable_for_device(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1304 static void spi_dma_sync_for_cpu(struct spi_controller *ctlr,
1305 struct spi_transfer *xfer)
1307 struct device *rx_dev = ctlr->cur_rx_dma_dev;
1308 struct device *tx_dev = ctlr->cur_tx_dma_dev;
1310 if (!ctlr->cur_msg_mapped)
1313 if (xfer->rx_sg.orig_nents)
1314 dma_sync_sgtable_for_cpu(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1315 if (xfer->tx_sg.orig_nents)
1316 dma_sync_sgtable_for_cpu(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1318 #else /* !CONFIG_HAS_DMA */
1319 static inline int __spi_map_msg(struct spi_controller *ctlr,
1320 struct spi_message *msg)
1325 static inline int __spi_unmap_msg(struct spi_controller *ctlr,
1326 struct spi_message *msg)
1331 static void spi_dma_sync_for_device(struct spi_controller *ctrl,
1332 struct spi_transfer *xfer)
1336 static void spi_dma_sync_for_cpu(struct spi_controller *ctrl,
1337 struct spi_transfer *xfer)
1340 #endif /* !CONFIG_HAS_DMA */
1342 static inline int spi_unmap_msg(struct spi_controller *ctlr,
1343 struct spi_message *msg)
1345 struct spi_transfer *xfer;
1347 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1349 * Restore the original value of tx_buf or rx_buf if they are
1352 if (xfer->tx_buf == ctlr->dummy_tx)
1353 xfer->tx_buf = NULL;
1354 if (xfer->rx_buf == ctlr->dummy_rx)
1355 xfer->rx_buf = NULL;
1358 return __spi_unmap_msg(ctlr, msg);
1361 static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1363 struct spi_transfer *xfer;
1365 unsigned int max_tx, max_rx;
1367 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1368 && !(msg->spi->mode & SPI_3WIRE)) {
1372 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1373 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1375 max_tx = max(xfer->len, max_tx);
1376 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1378 max_rx = max(xfer->len, max_rx);
1382 tmp = krealloc(ctlr->dummy_tx, max_tx,
1383 GFP_KERNEL | GFP_DMA | __GFP_ZERO);
1386 ctlr->dummy_tx = tmp;
1390 tmp = krealloc(ctlr->dummy_rx, max_rx,
1391 GFP_KERNEL | GFP_DMA);
1394 ctlr->dummy_rx = tmp;
1397 if (max_tx || max_rx) {
1398 list_for_each_entry(xfer, &msg->transfers,
1403 xfer->tx_buf = ctlr->dummy_tx;
1405 xfer->rx_buf = ctlr->dummy_rx;
1410 return __spi_map_msg(ctlr, msg);
1413 static int spi_transfer_wait(struct spi_controller *ctlr,
1414 struct spi_message *msg,
1415 struct spi_transfer *xfer)
1417 struct spi_statistics __percpu *statm = ctlr->pcpu_statistics;
1418 struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics;
1419 u32 speed_hz = xfer->speed_hz;
1420 unsigned long long ms;
1422 if (spi_controller_is_slave(ctlr)) {
1423 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1424 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1432 * For each byte we wait for 8 cycles of the SPI clock.
1433 * Since speed is defined in Hz and we want milliseconds,
1434 * use respective multiplier, but before the division,
1435 * otherwise we may get 0 for short transfers.
1437 ms = 8LL * MSEC_PER_SEC * xfer->len;
1438 do_div(ms, speed_hz);
1441 * Increase it twice and add 200 ms tolerance, use
1442 * predefined maximum in case of overflow.
1448 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1449 msecs_to_jiffies(ms));
1452 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1453 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1454 dev_err(&msg->spi->dev,
1455 "SPI transfer timed out\n");
1459 if (xfer->error & SPI_TRANS_FAIL_IO)
1466 static void _spi_transfer_delay_ns(u32 ns)
1470 if (ns <= NSEC_PER_USEC) {
1473 u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC);
1478 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1482 int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1484 u32 delay = _delay->value;
1485 u32 unit = _delay->unit;
1492 case SPI_DELAY_UNIT_USECS:
1493 delay *= NSEC_PER_USEC;
1495 case SPI_DELAY_UNIT_NSECS:
1496 /* Nothing to do here */
1498 case SPI_DELAY_UNIT_SCK:
1499 /* Clock cycles need to be obtained from spi_transfer */
1503 * If there is unknown effective speed, approximate it
1504 * by underestimating with half of the requested Hz.
1506 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1510 /* Convert delay to nanoseconds */
1511 delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz);
1519 EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1521 int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1530 delay = spi_delay_to_ns(_delay, xfer);
1534 _spi_transfer_delay_ns(delay);
1538 EXPORT_SYMBOL_GPL(spi_delay_exec);
1540 static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1541 struct spi_transfer *xfer)
1543 u32 default_delay_ns = 10 * NSEC_PER_USEC;
1544 u32 delay = xfer->cs_change_delay.value;
1545 u32 unit = xfer->cs_change_delay.unit;
1548 /* Return early on "fast" mode - for everything but USECS */
1550 if (unit == SPI_DELAY_UNIT_USECS)
1551 _spi_transfer_delay_ns(default_delay_ns);
1555 ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1557 dev_err_once(&msg->spi->dev,
1558 "Use of unsupported delay unit %i, using default of %luus\n",
1559 unit, default_delay_ns / NSEC_PER_USEC);
1560 _spi_transfer_delay_ns(default_delay_ns);
1564 void spi_transfer_cs_change_delay_exec(struct spi_message *msg,
1565 struct spi_transfer *xfer)
1567 _spi_transfer_cs_change_delay(msg, xfer);
1569 EXPORT_SYMBOL_GPL(spi_transfer_cs_change_delay_exec);
1572 * spi_transfer_one_message - Default implementation of transfer_one_message()
1574 * This is a standard implementation of transfer_one_message() for
1575 * drivers which implement a transfer_one() operation. It provides
1576 * standard handling of delays and chip select management.
1578 static int spi_transfer_one_message(struct spi_controller *ctlr,
1579 struct spi_message *msg)
1581 struct spi_transfer *xfer;
1582 bool keep_cs = false;
1584 struct spi_statistics __percpu *statm = ctlr->pcpu_statistics;
1585 struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics;
1587 xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list);
1588 spi_set_cs(msg->spi, !xfer->cs_off, false);
1590 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1591 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1593 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1594 trace_spi_transfer_start(msg, xfer);
1596 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1597 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1599 if (!ctlr->ptp_sts_supported) {
1600 xfer->ptp_sts_word_pre = 0;
1601 ptp_read_system_prets(xfer->ptp_sts);
1604 if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) {
1605 reinit_completion(&ctlr->xfer_completion);
1608 spi_dma_sync_for_device(ctlr, xfer);
1609 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1611 spi_dma_sync_for_cpu(ctlr, xfer);
1613 if (ctlr->cur_msg_mapped &&
1614 (xfer->error & SPI_TRANS_FAIL_NO_START)) {
1615 __spi_unmap_msg(ctlr, msg);
1616 ctlr->fallback = true;
1617 xfer->error &= ~SPI_TRANS_FAIL_NO_START;
1621 SPI_STATISTICS_INCREMENT_FIELD(statm,
1623 SPI_STATISTICS_INCREMENT_FIELD(stats,
1625 dev_err(&msg->spi->dev,
1626 "SPI transfer failed: %d\n", ret);
1631 ret = spi_transfer_wait(ctlr, msg, xfer);
1636 spi_dma_sync_for_cpu(ctlr, xfer);
1639 dev_err(&msg->spi->dev,
1640 "Bufferless transfer has length %u\n",
1644 if (!ctlr->ptp_sts_supported) {
1645 ptp_read_system_postts(xfer->ptp_sts);
1646 xfer->ptp_sts_word_post = xfer->len;
1649 trace_spi_transfer_stop(msg, xfer);
1651 if (msg->status != -EINPROGRESS)
1654 spi_transfer_delay_exec(xfer);
1656 if (xfer->cs_change) {
1657 if (list_is_last(&xfer->transfer_list,
1662 spi_set_cs(msg->spi, false, false);
1663 _spi_transfer_cs_change_delay(msg, xfer);
1664 if (!list_next_entry(xfer, transfer_list)->cs_off)
1665 spi_set_cs(msg->spi, true, false);
1667 } else if (!list_is_last(&xfer->transfer_list, &msg->transfers) &&
1668 xfer->cs_off != list_next_entry(xfer, transfer_list)->cs_off) {
1669 spi_set_cs(msg->spi, xfer->cs_off, false);
1672 msg->actual_length += xfer->len;
1676 if (ret != 0 || !keep_cs)
1677 spi_set_cs(msg->spi, false, false);
1679 if (msg->status == -EINPROGRESS)
1682 if (msg->status && ctlr->handle_err)
1683 ctlr->handle_err(ctlr, msg);
1685 spi_finalize_current_message(ctlr);
1691 * spi_finalize_current_transfer - report completion of a transfer
1692 * @ctlr: the controller reporting completion
1694 * Called by SPI drivers using the core transfer_one_message()
1695 * implementation to notify it that the current interrupt driven
1696 * transfer has finished and the next one may be scheduled.
1698 void spi_finalize_current_transfer(struct spi_controller *ctlr)
1700 complete(&ctlr->xfer_completion);
1702 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1704 static void spi_idle_runtime_pm(struct spi_controller *ctlr)
1706 if (ctlr->auto_runtime_pm) {
1707 pm_runtime_mark_last_busy(ctlr->dev.parent);
1708 pm_runtime_put_autosuspend(ctlr->dev.parent);
1712 static int __spi_pump_transfer_message(struct spi_controller *ctlr,
1713 struct spi_message *msg, bool was_busy)
1715 struct spi_transfer *xfer;
1718 if (!was_busy && ctlr->auto_runtime_pm) {
1719 ret = pm_runtime_get_sync(ctlr->dev.parent);
1721 pm_runtime_put_noidle(ctlr->dev.parent);
1722 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1726 spi_finalize_current_message(ctlr);
1733 trace_spi_controller_busy(ctlr);
1735 if (!was_busy && ctlr->prepare_transfer_hardware) {
1736 ret = ctlr->prepare_transfer_hardware(ctlr);
1739 "failed to prepare transfer hardware: %d\n",
1742 if (ctlr->auto_runtime_pm)
1743 pm_runtime_put(ctlr->dev.parent);
1746 spi_finalize_current_message(ctlr);
1752 trace_spi_message_start(msg);
1755 * If an SPI controller does not support toggling the CS line on each
1756 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
1757 * for the CS line, we can emulate the CS-per-word hardware function by
1758 * splitting transfers into one-word transfers and ensuring that
1759 * cs_change is set for each transfer.
1761 if ((msg->spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
1762 spi_is_csgpiod(msg->spi))) {
1763 ret = spi_split_transfers_maxwords(ctlr, msg, 1, GFP_KERNEL);
1766 spi_finalize_current_message(ctlr);
1770 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1771 /* Don't change cs_change on the last entry in the list */
1772 if (list_is_last(&xfer->transfer_list, &msg->transfers))
1774 xfer->cs_change = 1;
1777 ret = spi_split_transfers_maxsize(ctlr, msg,
1778 spi_max_transfer_size(msg->spi),
1779 GFP_KERNEL | GFP_DMA);
1782 spi_finalize_current_message(ctlr);
1787 if (ctlr->prepare_message) {
1788 ret = ctlr->prepare_message(ctlr, msg);
1790 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1793 spi_finalize_current_message(ctlr);
1796 msg->prepared = true;
1799 ret = spi_map_msg(ctlr, msg);
1802 spi_finalize_current_message(ctlr);
1806 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1807 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1808 xfer->ptp_sts_word_pre = 0;
1809 ptp_read_system_prets(xfer->ptp_sts);
1814 * Drivers implementation of transfer_one_message() must arrange for
1815 * spi_finalize_current_message() to get called. Most drivers will do
1816 * this in the calling context, but some don't. For those cases, a
1817 * completion is used to guarantee that this function does not return
1818 * until spi_finalize_current_message() is done accessing
1820 * Use of the following two flags enable to opportunistically skip the
1821 * use of the completion since its use involves expensive spin locks.
1822 * In case of a race with the context that calls
1823 * spi_finalize_current_message() the completion will always be used,
1824 * due to strict ordering of these flags using barriers.
1826 WRITE_ONCE(ctlr->cur_msg_incomplete, true);
1827 WRITE_ONCE(ctlr->cur_msg_need_completion, false);
1828 reinit_completion(&ctlr->cur_msg_completion);
1829 smp_wmb(); /* Make these available to spi_finalize_current_message() */
1831 ret = ctlr->transfer_one_message(ctlr, msg);
1834 "failed to transfer one message from queue\n");
1838 WRITE_ONCE(ctlr->cur_msg_need_completion, true);
1839 smp_mb(); /* See spi_finalize_current_message()... */
1840 if (READ_ONCE(ctlr->cur_msg_incomplete))
1841 wait_for_completion(&ctlr->cur_msg_completion);
1847 * __spi_pump_messages - function which processes SPI message queue
1848 * @ctlr: controller to process queue for
1849 * @in_kthread: true if we are in the context of the message pump thread
1851 * This function checks if there is any SPI message in the queue that
1852 * needs processing and if so call out to the driver to initialize hardware
1853 * and transfer each message.
1855 * Note that it is called both from the kthread itself and also from
1856 * inside spi_sync(); the queue extraction handling at the top of the
1857 * function should deal with this safely.
1859 static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1861 struct spi_message *msg;
1862 bool was_busy = false;
1863 unsigned long flags;
1866 /* Take the I/O mutex */
1867 mutex_lock(&ctlr->io_mutex);
1870 spin_lock_irqsave(&ctlr->queue_lock, flags);
1872 /* Make sure we are not already running a message */
1876 /* Check if the queue is idle */
1877 if (list_empty(&ctlr->queue) || !ctlr->running) {
1881 /* Defer any non-atomic teardown to the thread */
1883 if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
1884 !ctlr->unprepare_transfer_hardware) {
1885 spi_idle_runtime_pm(ctlr);
1887 ctlr->queue_empty = true;
1888 trace_spi_controller_idle(ctlr);
1890 kthread_queue_work(ctlr->kworker,
1891 &ctlr->pump_messages);
1897 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1899 kfree(ctlr->dummy_rx);
1900 ctlr->dummy_rx = NULL;
1901 kfree(ctlr->dummy_tx);
1902 ctlr->dummy_tx = NULL;
1903 if (ctlr->unprepare_transfer_hardware &&
1904 ctlr->unprepare_transfer_hardware(ctlr))
1906 "failed to unprepare transfer hardware\n");
1907 spi_idle_runtime_pm(ctlr);
1908 trace_spi_controller_idle(ctlr);
1910 spin_lock_irqsave(&ctlr->queue_lock, flags);
1911 ctlr->queue_empty = true;
1915 /* Extract head of queue */
1916 msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1917 ctlr->cur_msg = msg;
1919 list_del_init(&msg->queue);
1924 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1926 ret = __spi_pump_transfer_message(ctlr, msg, was_busy);
1927 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1929 ctlr->cur_msg = NULL;
1930 ctlr->fallback = false;
1932 mutex_unlock(&ctlr->io_mutex);
1934 /* Prod the scheduler in case transfer_one() was busy waiting */
1940 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1941 mutex_unlock(&ctlr->io_mutex);
1945 * spi_pump_messages - kthread work function which processes spi message queue
1946 * @work: pointer to kthread work struct contained in the controller struct
1948 static void spi_pump_messages(struct kthread_work *work)
1950 struct spi_controller *ctlr =
1951 container_of(work, struct spi_controller, pump_messages);
1953 __spi_pump_messages(ctlr, true);
1957 * spi_take_timestamp_pre - helper to collect the beginning of the TX timestamp
1958 * @ctlr: Pointer to the spi_controller structure of the driver
1959 * @xfer: Pointer to the transfer being timestamped
1960 * @progress: How many words (not bytes) have been transferred so far
1961 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1962 * transfer, for less jitter in time measurement. Only compatible
1963 * with PIO drivers. If true, must follow up with
1964 * spi_take_timestamp_post or otherwise system will crash.
1965 * WARNING: for fully predictable results, the CPU frequency must
1966 * also be under control (governor).
1968 * This is a helper for drivers to collect the beginning of the TX timestamp
1969 * for the requested byte from the SPI transfer. The frequency with which this
1970 * function must be called (once per word, once for the whole transfer, once
1971 * per batch of words etc) is arbitrary as long as the @tx buffer offset is
1972 * greater than or equal to the requested byte at the time of the call. The
1973 * timestamp is only taken once, at the first such call. It is assumed that
1974 * the driver advances its @tx buffer pointer monotonically.
1976 void spi_take_timestamp_pre(struct spi_controller *ctlr,
1977 struct spi_transfer *xfer,
1978 size_t progress, bool irqs_off)
1983 if (xfer->timestamped)
1986 if (progress > xfer->ptp_sts_word_pre)
1989 /* Capture the resolution of the timestamp */
1990 xfer->ptp_sts_word_pre = progress;
1993 local_irq_save(ctlr->irq_flags);
1997 ptp_read_system_prets(xfer->ptp_sts);
1999 EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
2002 * spi_take_timestamp_post - helper to collect the end of the TX timestamp
2003 * @ctlr: Pointer to the spi_controller structure of the driver
2004 * @xfer: Pointer to the transfer being timestamped
2005 * @progress: How many words (not bytes) have been transferred so far
2006 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
2008 * This is a helper for drivers to collect the end of the TX timestamp for
2009 * the requested byte from the SPI transfer. Can be called with an arbitrary
2010 * frequency: only the first call where @tx exceeds or is equal to the
2011 * requested word will be timestamped.
2013 void spi_take_timestamp_post(struct spi_controller *ctlr,
2014 struct spi_transfer *xfer,
2015 size_t progress, bool irqs_off)
2020 if (xfer->timestamped)
2023 if (progress < xfer->ptp_sts_word_post)
2026 ptp_read_system_postts(xfer->ptp_sts);
2029 local_irq_restore(ctlr->irq_flags);
2033 /* Capture the resolution of the timestamp */
2034 xfer->ptp_sts_word_post = progress;
2036 xfer->timestamped = 1;
2038 EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
2041 * spi_set_thread_rt - set the controller to pump at realtime priority
2042 * @ctlr: controller to boost priority of
2044 * This can be called because the controller requested realtime priority
2045 * (by setting the ->rt value before calling spi_register_controller()) or
2046 * because a device on the bus said that its transfers needed realtime
2049 * NOTE: at the moment if any device on a bus says it needs realtime then
2050 * the thread will be at realtime priority for all transfers on that
2051 * controller. If this eventually becomes a problem we may see if we can
2052 * find a way to boost the priority only temporarily during relevant
2055 static void spi_set_thread_rt(struct spi_controller *ctlr)
2057 dev_info(&ctlr->dev,
2058 "will run message pump with realtime priority\n");
2059 sched_set_fifo(ctlr->kworker->task);
2062 static int spi_init_queue(struct spi_controller *ctlr)
2064 ctlr->running = false;
2066 ctlr->queue_empty = true;
2068 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
2069 if (IS_ERR(ctlr->kworker)) {
2070 dev_err(&ctlr->dev, "failed to create message pump kworker\n");
2071 return PTR_ERR(ctlr->kworker);
2074 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
2077 * Controller config will indicate if this controller should run the
2078 * message pump with high (realtime) priority to reduce the transfer
2079 * latency on the bus by minimising the delay between a transfer
2080 * request and the scheduling of the message pump thread. Without this
2081 * setting the message pump thread will remain at default priority.
2084 spi_set_thread_rt(ctlr);
2090 * spi_get_next_queued_message() - called by driver to check for queued
2092 * @ctlr: the controller to check for queued messages
2094 * If there are more messages in the queue, the next message is returned from
2097 * Return: the next message in the queue, else NULL if the queue is empty.
2099 struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
2101 struct spi_message *next;
2102 unsigned long flags;
2104 /* Get a pointer to the next message, if any */
2105 spin_lock_irqsave(&ctlr->queue_lock, flags);
2106 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
2108 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2112 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
2115 * spi_finalize_current_message() - the current message is complete
2116 * @ctlr: the controller to return the message to
2118 * Called by the driver to notify the core that the message in the front of the
2119 * queue is complete and can be removed from the queue.
2121 void spi_finalize_current_message(struct spi_controller *ctlr)
2123 struct spi_transfer *xfer;
2124 struct spi_message *mesg;
2127 mesg = ctlr->cur_msg;
2129 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
2130 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
2131 ptp_read_system_postts(xfer->ptp_sts);
2132 xfer->ptp_sts_word_post = xfer->len;
2136 if (unlikely(ctlr->ptp_sts_supported))
2137 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
2138 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
2140 spi_unmap_msg(ctlr, mesg);
2143 * In the prepare_messages callback the SPI bus has the opportunity
2144 * to split a transfer to smaller chunks.
2146 * Release the split transfers here since spi_map_msg() is done on
2147 * the split transfers.
2149 spi_res_release(ctlr, mesg);
2151 if (mesg->prepared && ctlr->unprepare_message) {
2152 ret = ctlr->unprepare_message(ctlr, mesg);
2154 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
2159 mesg->prepared = false;
2161 WRITE_ONCE(ctlr->cur_msg_incomplete, false);
2162 smp_mb(); /* See __spi_pump_transfer_message()... */
2163 if (READ_ONCE(ctlr->cur_msg_need_completion))
2164 complete(&ctlr->cur_msg_completion);
2166 trace_spi_message_done(mesg);
2170 mesg->complete(mesg->context);
2172 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
2174 static int spi_start_queue(struct spi_controller *ctlr)
2176 unsigned long flags;
2178 spin_lock_irqsave(&ctlr->queue_lock, flags);
2180 if (ctlr->running || ctlr->busy) {
2181 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2185 ctlr->running = true;
2186 ctlr->cur_msg = NULL;
2187 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2189 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
2194 static int spi_stop_queue(struct spi_controller *ctlr)
2196 unsigned long flags;
2197 unsigned limit = 500;
2200 spin_lock_irqsave(&ctlr->queue_lock, flags);
2203 * This is a bit lame, but is optimized for the common execution path.
2204 * A wait_queue on the ctlr->busy could be used, but then the common
2205 * execution path (pump_messages) would be required to call wake_up or
2206 * friends on every SPI message. Do this instead.
2208 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
2209 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2210 usleep_range(10000, 11000);
2211 spin_lock_irqsave(&ctlr->queue_lock, flags);
2214 if (!list_empty(&ctlr->queue) || ctlr->busy)
2217 ctlr->running = false;
2219 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2224 static int spi_destroy_queue(struct spi_controller *ctlr)
2228 ret = spi_stop_queue(ctlr);
2231 * kthread_flush_worker will block until all work is done.
2232 * If the reason that stop_queue timed out is that the work will never
2233 * finish, then it does no good to call flush/stop thread, so
2237 dev_err(&ctlr->dev, "problem destroying queue\n");
2241 kthread_destroy_worker(ctlr->kworker);
2246 static int __spi_queued_transfer(struct spi_device *spi,
2247 struct spi_message *msg,
2250 struct spi_controller *ctlr = spi->controller;
2251 unsigned long flags;
2253 spin_lock_irqsave(&ctlr->queue_lock, flags);
2255 if (!ctlr->running) {
2256 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2259 msg->actual_length = 0;
2260 msg->status = -EINPROGRESS;
2262 list_add_tail(&msg->queue, &ctlr->queue);
2263 ctlr->queue_empty = false;
2264 if (!ctlr->busy && need_pump)
2265 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
2267 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2272 * spi_queued_transfer - transfer function for queued transfers
2273 * @spi: SPI device which is requesting transfer
2274 * @msg: SPI message which is to handled is queued to driver queue
2276 * Return: zero on success, else a negative error code.
2278 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
2280 return __spi_queued_transfer(spi, msg, true);
2283 static int spi_controller_initialize_queue(struct spi_controller *ctlr)
2287 ctlr->transfer = spi_queued_transfer;
2288 if (!ctlr->transfer_one_message)
2289 ctlr->transfer_one_message = spi_transfer_one_message;
2291 /* Initialize and start queue */
2292 ret = spi_init_queue(ctlr);
2294 dev_err(&ctlr->dev, "problem initializing queue\n");
2295 goto err_init_queue;
2297 ctlr->queued = true;
2298 ret = spi_start_queue(ctlr);
2300 dev_err(&ctlr->dev, "problem starting queue\n");
2301 goto err_start_queue;
2307 spi_destroy_queue(ctlr);
2313 * spi_flush_queue - Send all pending messages in the queue from the callers'
2315 * @ctlr: controller to process queue for
2317 * This should be used when one wants to ensure all pending messages have been
2318 * sent before doing something. Is used by the spi-mem code to make sure SPI
2319 * memory operations do not preempt regular SPI transfers that have been queued
2320 * before the spi-mem operation.
2322 void spi_flush_queue(struct spi_controller *ctlr)
2324 if (ctlr->transfer == spi_queued_transfer)
2325 __spi_pump_messages(ctlr, false);
2328 /*-------------------------------------------------------------------------*/
2330 #if defined(CONFIG_OF)
2331 static void of_spi_parse_dt_cs_delay(struct device_node *nc,
2332 struct spi_delay *delay, const char *prop)
2336 if (!of_property_read_u32(nc, prop, &value)) {
2337 if (value > U16_MAX) {
2338 delay->value = DIV_ROUND_UP(value, 1000);
2339 delay->unit = SPI_DELAY_UNIT_USECS;
2341 delay->value = value;
2342 delay->unit = SPI_DELAY_UNIT_NSECS;
2347 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
2348 struct device_node *nc)
2350 u32 value, cs[SPI_CS_CNT_MAX];
2353 /* Mode (clock phase/polarity/etc.) */
2354 if (of_property_read_bool(nc, "spi-cpha"))
2355 spi->mode |= SPI_CPHA;
2356 if (of_property_read_bool(nc, "spi-cpol"))
2357 spi->mode |= SPI_CPOL;
2358 if (of_property_read_bool(nc, "spi-3wire"))
2359 spi->mode |= SPI_3WIRE;
2360 if (of_property_read_bool(nc, "spi-lsb-first"))
2361 spi->mode |= SPI_LSB_FIRST;
2362 if (of_property_read_bool(nc, "spi-cs-high"))
2363 spi->mode |= SPI_CS_HIGH;
2365 /* Device DUAL/QUAD mode */
2366 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
2369 spi->mode |= SPI_NO_TX;
2374 spi->mode |= SPI_TX_DUAL;
2377 spi->mode |= SPI_TX_QUAD;
2380 spi->mode |= SPI_TX_OCTAL;
2383 dev_warn(&ctlr->dev,
2384 "spi-tx-bus-width %d not supported\n",
2390 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
2393 spi->mode |= SPI_NO_RX;
2398 spi->mode |= SPI_RX_DUAL;
2401 spi->mode |= SPI_RX_QUAD;
2404 spi->mode |= SPI_RX_OCTAL;
2407 dev_warn(&ctlr->dev,
2408 "spi-rx-bus-width %d not supported\n",
2414 if (spi_controller_is_slave(ctlr)) {
2415 if (!of_node_name_eq(nc, "slave")) {
2416 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
2423 if (ctlr->num_chipselect > SPI_CS_CNT_MAX) {
2424 dev_err(&ctlr->dev, "No. of CS is more than max. no. of supported CS\n");
2429 * Zero(0) is a valid physical CS value and can be located at any
2430 * logical CS in the spi->chip_select[]. If all the physical CS
2431 * are initialized to 0 then It would be difficult to differentiate
2432 * between a valid physical CS 0 & an unused logical CS whose physical
2433 * CS can be 0. As a solution to this issue initialize all the CS to 0xFF.
2434 * Now all the unused logical CS will have 0xFF physical CS value & can be
2435 * ignore while performing physical CS validity checks.
2437 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
2438 spi_set_chipselect(spi, idx, 0xFF);
2440 /* Device address */
2441 rc = of_property_read_variable_u32_array(nc, "reg", &cs[0], 1,
2444 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
2448 if (rc > ctlr->num_chipselect) {
2449 dev_err(&ctlr->dev, "%pOF has number of CS > ctlr->num_chipselect (%d)\n",
2453 if ((of_property_read_bool(nc, "parallel-memories")) &&
2454 (!(ctlr->flags & SPI_CONTROLLER_MULTI_CS))) {
2455 dev_err(&ctlr->dev, "SPI controller doesn't support multi CS\n");
2458 for (idx = 0; idx < rc; idx++)
2459 spi_set_chipselect(spi, idx, cs[idx]);
2462 * spi->chip_select[i] gives the corresponding physical CS for logical CS i
2463 * logical CS number is represented by setting the ith bit in spi->cs_index_mask
2464 * So, for example, if spi->cs_index_mask = 0x01 then logical CS number is 0 and
2465 * spi->chip_select[0] will give the physical CS.
2466 * By default spi->chip_select[0] will hold the physical CS number so, set
2467 * spi->cs_index_mask as 0x01.
2469 spi->cs_index_mask = 0x01;
2472 if (!of_property_read_u32(nc, "spi-max-frequency", &value))
2473 spi->max_speed_hz = value;
2475 /* Device CS delays */
2476 of_spi_parse_dt_cs_delay(nc, &spi->cs_setup, "spi-cs-setup-delay-ns");
2477 of_spi_parse_dt_cs_delay(nc, &spi->cs_hold, "spi-cs-hold-delay-ns");
2478 of_spi_parse_dt_cs_delay(nc, &spi->cs_inactive, "spi-cs-inactive-delay-ns");
2483 static struct spi_device *
2484 of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
2486 struct spi_device *spi;
2489 /* Alloc an spi_device */
2490 spi = spi_alloc_device(ctlr);
2492 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
2497 /* Select device driver */
2498 rc = of_alias_from_compatible(nc, spi->modalias,
2499 sizeof(spi->modalias));
2501 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
2505 rc = of_spi_parse_dt(ctlr, spi, nc);
2509 /* Store a pointer to the node in the device structure */
2512 device_set_node(&spi->dev, of_fwnode_handle(nc));
2514 /* Register the new device */
2515 rc = spi_add_device(spi);
2517 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
2518 goto err_of_node_put;
2531 * of_register_spi_devices() - Register child devices onto the SPI bus
2532 * @ctlr: Pointer to spi_controller device
2534 * Registers an spi_device for each child node of controller node which
2535 * represents a valid SPI slave.
2537 static void of_register_spi_devices(struct spi_controller *ctlr)
2539 struct spi_device *spi;
2540 struct device_node *nc;
2542 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2543 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2545 spi = of_register_spi_device(ctlr, nc);
2547 dev_warn(&ctlr->dev,
2548 "Failed to create SPI device for %pOF\n", nc);
2549 of_node_clear_flag(nc, OF_POPULATED);
2554 static void of_register_spi_devices(struct spi_controller *ctlr) { }
2558 * spi_new_ancillary_device() - Register ancillary SPI device
2559 * @spi: Pointer to the main SPI device registering the ancillary device
2560 * @chip_select: Chip Select of the ancillary device
2562 * Register an ancillary SPI device; for example some chips have a chip-select
2563 * for normal device usage and another one for setup/firmware upload.
2565 * This may only be called from main SPI device's probe routine.
2567 * Return: 0 on success; negative errno on failure
2569 struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
2572 struct spi_controller *ctlr = spi->controller;
2573 struct spi_device *ancillary;
2577 /* Alloc an spi_device */
2578 ancillary = spi_alloc_device(ctlr);
2584 strscpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));
2587 * Zero(0) is a valid physical CS value and can be located at any
2588 * logical CS in the spi->chip_select[]. If all the physical CS
2589 * are initialized to 0 then It would be difficult to differentiate
2590 * between a valid physical CS 0 & an unused logical CS whose physical
2591 * CS can be 0. As a solution to this issue initialize all the CS to 0xFF.
2592 * Now all the unused logical CS will have 0xFF physical CS value & can be
2593 * ignore while performing physical CS validity checks.
2595 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
2596 spi_set_chipselect(ancillary, idx, 0xFF);
2598 /* Use provided chip-select for ancillary device */
2599 spi_set_chipselect(ancillary, 0, chip_select);
2601 /* Take over SPI mode/speed from SPI main device */
2602 ancillary->max_speed_hz = spi->max_speed_hz;
2603 ancillary->mode = spi->mode;
2605 * spi->chip_select[i] gives the corresponding physical CS for logical CS i
2606 * logical CS number is represented by setting the ith bit in spi->cs_index_mask
2607 * So, for example, if spi->cs_index_mask = 0x01 then logical CS number is 0 and
2608 * spi->chip_select[0] will give the physical CS.
2609 * By default spi->chip_select[0] will hold the physical CS number so, set
2610 * spi->cs_index_mask as 0x01.
2612 ancillary->cs_index_mask = 0x01;
2614 WARN_ON(!mutex_is_locked(&ctlr->add_lock));
2616 /* Register the new device */
2617 rc = __spi_add_device(ancillary);
2619 dev_err(&spi->dev, "failed to register ancillary device\n");
2626 spi_dev_put(ancillary);
2629 EXPORT_SYMBOL_GPL(spi_new_ancillary_device);
2632 struct acpi_spi_lookup {
2633 struct spi_controller *ctlr;
2643 static int acpi_spi_count(struct acpi_resource *ares, void *data)
2645 struct acpi_resource_spi_serialbus *sb;
2648 if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
2651 sb = &ares->data.spi_serial_bus;
2652 if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_SPI)
2655 *count = *count + 1;
2661 * acpi_spi_count_resources - Count the number of SpiSerialBus resources
2662 * @adev: ACPI device
2664 * Return: the number of SpiSerialBus resources in the ACPI-device's
2665 * resource-list; or a negative error code.
2667 int acpi_spi_count_resources(struct acpi_device *adev)
2673 ret = acpi_dev_get_resources(adev, &r, acpi_spi_count, &count);
2677 acpi_dev_free_resource_list(&r);
2681 EXPORT_SYMBOL_GPL(acpi_spi_count_resources);
2683 static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2684 struct acpi_spi_lookup *lookup)
2686 const union acpi_object *obj;
2688 if (!x86_apple_machine)
2691 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2692 && obj->buffer.length >= 4)
2693 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2695 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2696 && obj->buffer.length == 8)
2697 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2699 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2700 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2701 lookup->mode |= SPI_LSB_FIRST;
2703 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2704 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2705 lookup->mode |= SPI_CPOL;
2707 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2708 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2709 lookup->mode |= SPI_CPHA;
2712 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2714 struct acpi_spi_lookup *lookup = data;
2715 struct spi_controller *ctlr = lookup->ctlr;
2717 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2718 struct acpi_resource_spi_serialbus *sb;
2719 acpi_handle parent_handle;
2722 sb = &ares->data.spi_serial_bus;
2723 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2725 if (lookup->index != -1 && lookup->n++ != lookup->index)
2728 status = acpi_get_handle(NULL,
2729 sb->resource_source.string_ptr,
2732 if (ACPI_FAILURE(status))
2736 if (ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
2739 struct acpi_device *adev;
2741 adev = acpi_fetch_acpi_dev(parent_handle);
2745 ctlr = acpi_spi_find_controller_by_adev(adev);
2747 return -EPROBE_DEFER;
2749 lookup->ctlr = ctlr;
2753 * ACPI DeviceSelection numbering is handled by the
2754 * host controller driver in Windows and can vary
2755 * from driver to driver. In Linux we always expect
2756 * 0 .. max - 1 so we need to ask the driver to
2757 * translate between the two schemes.
2759 if (ctlr->fw_translate_cs) {
2760 int cs = ctlr->fw_translate_cs(ctlr,
2761 sb->device_selection);
2764 lookup->chip_select = cs;
2766 lookup->chip_select = sb->device_selection;
2769 lookup->max_speed_hz = sb->connection_speed;
2770 lookup->bits_per_word = sb->data_bit_length;
2772 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2773 lookup->mode |= SPI_CPHA;
2774 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2775 lookup->mode |= SPI_CPOL;
2776 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2777 lookup->mode |= SPI_CS_HIGH;
2779 } else if (lookup->irq < 0) {
2782 if (acpi_dev_resource_interrupt(ares, 0, &r))
2783 lookup->irq = r.start;
2786 /* Always tell the ACPI core to skip this resource */
2791 * acpi_spi_device_alloc - Allocate a spi device, and fill it in with ACPI information
2792 * @ctlr: controller to which the spi device belongs
2793 * @adev: ACPI Device for the spi device
2794 * @index: Index of the spi resource inside the ACPI Node
2796 * This should be used to allocate a new SPI device from and ACPI Device node.
2797 * The caller is responsible for calling spi_add_device to register the SPI device.
2799 * If ctlr is set to NULL, the Controller for the SPI device will be looked up
2800 * using the resource.
2801 * If index is set to -1, index is not used.
2802 * Note: If index is -1, ctlr must be set.
2804 * Return: a pointer to the new device, or ERR_PTR on error.
2806 struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
2807 struct acpi_device *adev,
2810 acpi_handle parent_handle = NULL;
2811 struct list_head resource_list;
2812 struct acpi_spi_lookup lookup = {};
2813 struct spi_device *spi;
2817 if (!ctlr && index == -1)
2818 return ERR_PTR(-EINVAL);
2822 lookup.index = index;
2825 INIT_LIST_HEAD(&resource_list);
2826 ret = acpi_dev_get_resources(adev, &resource_list,
2827 acpi_spi_add_resource, &lookup);
2828 acpi_dev_free_resource_list(&resource_list);
2831 /* Found SPI in _CRS but it points to another controller */
2832 return ERR_PTR(ret);
2834 if (!lookup.max_speed_hz &&
2835 ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
2836 ACPI_HANDLE(lookup.ctlr->dev.parent) == parent_handle) {
2837 /* Apple does not use _CRS but nested devices for SPI slaves */
2838 acpi_spi_parse_apple_properties(adev, &lookup);
2841 if (!lookup.max_speed_hz)
2842 return ERR_PTR(-ENODEV);
2844 spi = spi_alloc_device(lookup.ctlr);
2846 dev_err(&lookup.ctlr->dev, "failed to allocate SPI device for %s\n",
2847 dev_name(&adev->dev));
2848 return ERR_PTR(-ENOMEM);
2852 * Zero(0) is a valid physical CS value and can be located at any
2853 * logical CS in the spi->chip_select[]. If all the physical CS
2854 * are initialized to 0 then It would be difficult to differentiate
2855 * between a valid physical CS 0 & an unused logical CS whose physical
2856 * CS can be 0. As a solution to this issue initialize all the CS to 0xFF.
2857 * Now all the unused logical CS will have 0xFF physical CS value & can be
2858 * ignore while performing physical CS validity checks.
2860 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
2861 spi_set_chipselect(spi, idx, 0xFF);
2863 ACPI_COMPANION_SET(&spi->dev, adev);
2864 spi->max_speed_hz = lookup.max_speed_hz;
2865 spi->mode |= lookup.mode;
2866 spi->irq = lookup.irq;
2867 spi->bits_per_word = lookup.bits_per_word;
2868 spi_set_chipselect(spi, 0, lookup.chip_select);
2870 * spi->chip_select[i] gives the corresponding physical CS for logical CS i
2871 * logical CS number is represented by setting the ith bit in spi->cs_index_mask
2872 * So, for example, if spi->cs_index_mask = 0x01 then logical CS number is 0 and
2873 * spi->chip_select[0] will give the physical CS.
2874 * By default spi->chip_select[0] will hold the physical CS number so, set
2875 * spi->cs_index_mask as 0x01.
2877 spi->cs_index_mask = 0x01;
2881 EXPORT_SYMBOL_GPL(acpi_spi_device_alloc);
2883 static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2884 struct acpi_device *adev)
2886 struct spi_device *spi;
2888 if (acpi_bus_get_status(adev) || !adev->status.present ||
2889 acpi_device_enumerated(adev))
2892 spi = acpi_spi_device_alloc(ctlr, adev, -1);
2894 if (PTR_ERR(spi) == -ENOMEM)
2895 return AE_NO_MEMORY;
2900 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2901 sizeof(spi->modalias));
2904 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
2906 acpi_device_set_enumerated(adev);
2908 adev->power.flags.ignore_parent = true;
2909 if (spi_add_device(spi)) {
2910 adev->power.flags.ignore_parent = false;
2911 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2912 dev_name(&adev->dev));
2919 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2920 void *data, void **return_value)
2922 struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
2923 struct spi_controller *ctlr = data;
2928 return acpi_register_spi_device(ctlr, adev);
2931 #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2933 static void acpi_register_spi_devices(struct spi_controller *ctlr)
2938 handle = ACPI_HANDLE(ctlr->dev.parent);
2942 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2943 SPI_ACPI_ENUMERATE_MAX_DEPTH,
2944 acpi_spi_add_device, NULL, ctlr, NULL);
2945 if (ACPI_FAILURE(status))
2946 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2949 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2950 #endif /* CONFIG_ACPI */
2952 static void spi_controller_release(struct device *dev)
2954 struct spi_controller *ctlr;
2956 ctlr = container_of(dev, struct spi_controller, dev);
2960 static struct class spi_master_class = {
2961 .name = "spi_master",
2962 .dev_release = spi_controller_release,
2963 .dev_groups = spi_master_groups,
2966 #ifdef CONFIG_SPI_SLAVE
2968 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2970 * @spi: device used for the current transfer
2972 int spi_slave_abort(struct spi_device *spi)
2974 struct spi_controller *ctlr = spi->controller;
2976 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
2977 return ctlr->slave_abort(ctlr);
2981 EXPORT_SYMBOL_GPL(spi_slave_abort);
2983 int spi_target_abort(struct spi_device *spi)
2985 struct spi_controller *ctlr = spi->controller;
2987 if (spi_controller_is_target(ctlr) && ctlr->target_abort)
2988 return ctlr->target_abort(ctlr);
2992 EXPORT_SYMBOL_GPL(spi_target_abort);
2994 static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2997 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2999 struct device *child;
3001 child = device_find_any_child(&ctlr->dev);
3002 return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL);
3005 static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
3006 const char *buf, size_t count)
3008 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
3010 struct spi_device *spi;
3011 struct device *child;
3015 rc = sscanf(buf, "%31s", name);
3016 if (rc != 1 || !name[0])
3019 child = device_find_any_child(&ctlr->dev);
3021 /* Remove registered slave */
3022 device_unregister(child);
3026 if (strcmp(name, "(null)")) {
3027 /* Register new slave */
3028 spi = spi_alloc_device(ctlr);
3032 strscpy(spi->modalias, name, sizeof(spi->modalias));
3034 rc = spi_add_device(spi);
3044 static DEVICE_ATTR_RW(slave);
3046 static struct attribute *spi_slave_attrs[] = {
3047 &dev_attr_slave.attr,
3051 static const struct attribute_group spi_slave_group = {
3052 .attrs = spi_slave_attrs,
3055 static const struct attribute_group *spi_slave_groups[] = {
3056 &spi_controller_statistics_group,
3061 static struct class spi_slave_class = {
3062 .name = "spi_slave",
3063 .dev_release = spi_controller_release,
3064 .dev_groups = spi_slave_groups,
3067 extern struct class spi_slave_class; /* dummy */
3071 * __spi_alloc_controller - allocate an SPI master or slave controller
3072 * @dev: the controller, possibly using the platform_bus
3073 * @size: how much zeroed driver-private data to allocate; the pointer to this
3074 * memory is in the driver_data field of the returned device, accessible
3075 * with spi_controller_get_devdata(); the memory is cacheline aligned;
3076 * drivers granting DMA access to portions of their private data need to
3077 * round up @size using ALIGN(size, dma_get_cache_alignment()).
3078 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
3079 * slave (true) controller
3080 * Context: can sleep
3082 * This call is used only by SPI controller drivers, which are the
3083 * only ones directly touching chip registers. It's how they allocate
3084 * an spi_controller structure, prior to calling spi_register_controller().
3086 * This must be called from context that can sleep.
3088 * The caller is responsible for assigning the bus number and initializing the
3089 * controller's methods before calling spi_register_controller(); and (after
3090 * errors adding the device) calling spi_controller_put() to prevent a memory
3093 * Return: the SPI controller structure on success, else NULL.
3095 struct spi_controller *__spi_alloc_controller(struct device *dev,
3096 unsigned int size, bool slave)
3098 struct spi_controller *ctlr;
3099 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
3104 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
3108 device_initialize(&ctlr->dev);
3109 INIT_LIST_HEAD(&ctlr->queue);
3110 spin_lock_init(&ctlr->queue_lock);
3111 spin_lock_init(&ctlr->bus_lock_spinlock);
3112 mutex_init(&ctlr->bus_lock_mutex);
3113 mutex_init(&ctlr->io_mutex);
3114 mutex_init(&ctlr->add_lock);
3116 ctlr->num_chipselect = 1;
3117 ctlr->slave = slave;
3118 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
3119 ctlr->dev.class = &spi_slave_class;
3121 ctlr->dev.class = &spi_master_class;
3122 ctlr->dev.parent = dev;
3123 pm_suspend_ignore_children(&ctlr->dev, true);
3124 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
3128 EXPORT_SYMBOL_GPL(__spi_alloc_controller);
3130 static void devm_spi_release_controller(struct device *dev, void *ctlr)
3132 spi_controller_put(*(struct spi_controller **)ctlr);
3136 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
3137 * @dev: physical device of SPI controller
3138 * @size: how much zeroed driver-private data to allocate
3139 * @slave: whether to allocate an SPI master (false) or SPI slave (true)
3140 * Context: can sleep
3142 * Allocate an SPI controller and automatically release a reference on it
3143 * when @dev is unbound from its driver. Drivers are thus relieved from
3144 * having to call spi_controller_put().
3146 * The arguments to this function are identical to __spi_alloc_controller().
3148 * Return: the SPI controller structure on success, else NULL.
3150 struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
3154 struct spi_controller **ptr, *ctlr;
3156 ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),
3161 ctlr = __spi_alloc_controller(dev, size, slave);
3163 ctlr->devm_allocated = true;
3165 devres_add(dev, ptr);
3172 EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);
3175 * spi_get_gpio_descs() - grab chip select GPIOs for the master
3176 * @ctlr: The SPI master to grab GPIO descriptors for
3178 static int spi_get_gpio_descs(struct spi_controller *ctlr)
3181 struct gpio_desc **cs;
3182 struct device *dev = &ctlr->dev;
3183 unsigned long native_cs_mask = 0;
3184 unsigned int num_cs_gpios = 0;
3186 nb = gpiod_count(dev, "cs");
3188 /* No GPIOs at all is fine, else return the error */
3194 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
3196 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
3200 ctlr->cs_gpiods = cs;
3202 for (i = 0; i < nb; i++) {
3204 * Most chipselects are active low, the inverted
3205 * semantics are handled by special quirks in gpiolib,
3206 * so initializing them GPIOD_OUT_LOW here means
3207 * "unasserted", in most cases this will drive the physical
3210 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
3213 return PTR_ERR(cs[i]);
3217 * If we find a CS GPIO, name it after the device and
3222 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
3226 gpiod_set_consumer_name(cs[i], gpioname);
3231 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
3232 dev_err(dev, "Invalid native chip select %d\n", i);
3235 native_cs_mask |= BIT(i);
3238 ctlr->unused_native_cs = ffs(~native_cs_mask) - 1;
3240 if ((ctlr->flags & SPI_CONTROLLER_GPIO_SS) && num_cs_gpios &&
3241 ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {
3242 dev_err(dev, "No unused native chip select available\n");
3249 static int spi_controller_check_ops(struct spi_controller *ctlr)
3252 * The controller may implement only the high-level SPI-memory like
3253 * operations if it does not support regular SPI transfers, and this is
3255 * If ->mem_ops or ->mem_ops->exec_op is NULL, we request that at least
3256 * one of the ->transfer_xxx() method be implemented.
3258 if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
3259 if (!ctlr->transfer && !ctlr->transfer_one &&
3260 !ctlr->transfer_one_message) {
3268 /* Allocate dynamic bus number using Linux idr */
3269 static int spi_controller_id_alloc(struct spi_controller *ctlr, int start, int end)
3273 mutex_lock(&board_lock);
3274 id = idr_alloc(&spi_master_idr, ctlr, start, end, GFP_KERNEL);
3275 mutex_unlock(&board_lock);
3276 if (WARN(id < 0, "couldn't get idr"))
3277 return id == -ENOSPC ? -EBUSY : id;
3283 * spi_register_controller - register SPI master or slave controller
3284 * @ctlr: initialized master, originally from spi_alloc_master() or
3286 * Context: can sleep
3288 * SPI controllers connect to their drivers using some non-SPI bus,
3289 * such as the platform bus. The final stage of probe() in that code
3290 * includes calling spi_register_controller() to hook up to this SPI bus glue.
3292 * SPI controllers use board specific (often SOC specific) bus numbers,
3293 * and board-specific addressing for SPI devices combines those numbers
3294 * with chip select numbers. Since SPI does not directly support dynamic
3295 * device identification, boards need configuration tables telling which
3296 * chip is at which address.
3298 * This must be called from context that can sleep. It returns zero on
3299 * success, else a negative error code (dropping the controller's refcount).
3300 * After a successful return, the caller is responsible for calling
3301 * spi_unregister_controller().
3303 * Return: zero on success, else a negative error code.
3305 int spi_register_controller(struct spi_controller *ctlr)
3307 struct device *dev = ctlr->dev.parent;
3308 struct boardinfo *bi;
3317 * Make sure all necessary hooks are implemented before registering
3318 * the SPI controller.
3320 status = spi_controller_check_ops(ctlr);
3324 if (ctlr->bus_num < 0)
3325 ctlr->bus_num = of_alias_get_id(ctlr->dev.of_node, "spi");
3326 if (ctlr->bus_num >= 0) {
3327 /* Devices with a fixed bus num must check-in with the num */
3328 status = spi_controller_id_alloc(ctlr, ctlr->bus_num, ctlr->bus_num + 1);
3332 if (ctlr->bus_num < 0) {
3333 first_dynamic = of_alias_get_highest_id("spi");
3334 if (first_dynamic < 0)
3339 status = spi_controller_id_alloc(ctlr, first_dynamic, 0);
3343 ctlr->bus_lock_flag = 0;
3344 init_completion(&ctlr->xfer_completion);
3345 init_completion(&ctlr->cur_msg_completion);
3346 if (!ctlr->max_dma_len)
3347 ctlr->max_dma_len = INT_MAX;
3350 * Register the device, then userspace will see it.
3351 * Registration fails if the bus ID is in use.
3353 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
3355 if (!spi_controller_is_slave(ctlr) && ctlr->use_gpio_descriptors) {
3356 status = spi_get_gpio_descs(ctlr);
3360 * A controller using GPIO descriptors always
3361 * supports SPI_CS_HIGH if need be.
3363 ctlr->mode_bits |= SPI_CS_HIGH;
3367 * Even if it's just one always-selected device, there must
3368 * be at least one chipselect.
3370 if (!ctlr->num_chipselect) {
3375 /* Setting last_cs to -1 means no chip selected */
3376 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
3377 ctlr->last_cs[idx] = -1;
3379 status = device_add(&ctlr->dev);
3382 dev_dbg(dev, "registered %s %s\n",
3383 spi_controller_is_slave(ctlr) ? "slave" : "master",
3384 dev_name(&ctlr->dev));
3387 * If we're using a queued driver, start the queue. Note that we don't
3388 * need the queueing logic if the driver is only supporting high-level
3389 * memory operations.
3391 if (ctlr->transfer) {
3392 dev_info(dev, "controller is unqueued, this is deprecated\n");
3393 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
3394 status = spi_controller_initialize_queue(ctlr);
3396 device_del(&ctlr->dev);
3400 /* Add statistics */
3401 ctlr->pcpu_statistics = spi_alloc_pcpu_stats(dev);
3402 if (!ctlr->pcpu_statistics) {
3403 dev_err(dev, "Error allocating per-cpu statistics\n");
3408 mutex_lock(&board_lock);
3409 list_add_tail(&ctlr->list, &spi_controller_list);
3410 list_for_each_entry(bi, &board_list, list)
3411 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
3412 mutex_unlock(&board_lock);
3414 /* Register devices from the device tree and ACPI */
3415 of_register_spi_devices(ctlr);
3416 acpi_register_spi_devices(ctlr);
3420 spi_destroy_queue(ctlr);
3422 mutex_lock(&board_lock);
3423 idr_remove(&spi_master_idr, ctlr->bus_num);
3424 mutex_unlock(&board_lock);
3427 EXPORT_SYMBOL_GPL(spi_register_controller);
3429 static void devm_spi_unregister(struct device *dev, void *res)
3431 spi_unregister_controller(*(struct spi_controller **)res);
3435 * devm_spi_register_controller - register managed SPI master or slave
3437 * @dev: device managing SPI controller
3438 * @ctlr: initialized controller, originally from spi_alloc_master() or
3440 * Context: can sleep
3442 * Register a SPI device as with spi_register_controller() which will
3443 * automatically be unregistered and freed.
3445 * Return: zero on success, else a negative error code.
3447 int devm_spi_register_controller(struct device *dev,
3448 struct spi_controller *ctlr)
3450 struct spi_controller **ptr;
3453 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
3457 ret = spi_register_controller(ctlr);
3460 devres_add(dev, ptr);
3467 EXPORT_SYMBOL_GPL(devm_spi_register_controller);
3469 static int __unregister(struct device *dev, void *null)
3471 spi_unregister_device(to_spi_device(dev));
3476 * spi_unregister_controller - unregister SPI master or slave controller
3477 * @ctlr: the controller being unregistered
3478 * Context: can sleep
3480 * This call is used only by SPI controller drivers, which are the
3481 * only ones directly touching chip registers.
3483 * This must be called from context that can sleep.
3485 * Note that this function also drops a reference to the controller.
3487 void spi_unregister_controller(struct spi_controller *ctlr)
3489 struct spi_controller *found;
3490 int id = ctlr->bus_num;
3492 /* Prevent addition of new devices, unregister existing ones */
3493 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
3494 mutex_lock(&ctlr->add_lock);
3496 device_for_each_child(&ctlr->dev, NULL, __unregister);
3498 /* First make sure that this controller was ever added */
3499 mutex_lock(&board_lock);
3500 found = idr_find(&spi_master_idr, id);
3501 mutex_unlock(&board_lock);
3503 if (spi_destroy_queue(ctlr))
3504 dev_err(&ctlr->dev, "queue remove failed\n");
3506 mutex_lock(&board_lock);
3507 list_del(&ctlr->list);
3508 mutex_unlock(&board_lock);
3510 device_del(&ctlr->dev);
3513 mutex_lock(&board_lock);
3515 idr_remove(&spi_master_idr, id);
3516 mutex_unlock(&board_lock);
3518 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
3519 mutex_unlock(&ctlr->add_lock);
3522 * Release the last reference on the controller if its driver
3523 * has not yet been converted to devm_spi_alloc_master/slave().
3525 if (!ctlr->devm_allocated)
3526 put_device(&ctlr->dev);
3528 EXPORT_SYMBOL_GPL(spi_unregister_controller);
3530 static inline int __spi_check_suspended(const struct spi_controller *ctlr)
3532 return ctlr->flags & SPI_CONTROLLER_SUSPENDED ? -ESHUTDOWN : 0;
3535 static inline void __spi_mark_suspended(struct spi_controller *ctlr)
3537 mutex_lock(&ctlr->bus_lock_mutex);
3538 ctlr->flags |= SPI_CONTROLLER_SUSPENDED;
3539 mutex_unlock(&ctlr->bus_lock_mutex);
3542 static inline void __spi_mark_resumed(struct spi_controller *ctlr)
3544 mutex_lock(&ctlr->bus_lock_mutex);
3545 ctlr->flags &= ~SPI_CONTROLLER_SUSPENDED;
3546 mutex_unlock(&ctlr->bus_lock_mutex);
3549 int spi_controller_suspend(struct spi_controller *ctlr)
3553 /* Basically no-ops for non-queued controllers */
3555 ret = spi_stop_queue(ctlr);
3557 dev_err(&ctlr->dev, "queue stop failed\n");
3560 __spi_mark_suspended(ctlr);
3563 EXPORT_SYMBOL_GPL(spi_controller_suspend);
3565 int spi_controller_resume(struct spi_controller *ctlr)
3569 __spi_mark_resumed(ctlr);
3572 ret = spi_start_queue(ctlr);
3574 dev_err(&ctlr->dev, "queue restart failed\n");
3578 EXPORT_SYMBOL_GPL(spi_controller_resume);
3580 /*-------------------------------------------------------------------------*/
3582 /* Core methods for spi_message alterations */
3584 static void __spi_replace_transfers_release(struct spi_controller *ctlr,
3585 struct spi_message *msg,
3588 struct spi_replaced_transfers *rxfer = res;
3591 /* Call extra callback if requested */
3593 rxfer->release(ctlr, msg, res);
3595 /* Insert replaced transfers back into the message */
3596 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
3598 /* Remove the formerly inserted entries */
3599 for (i = 0; i < rxfer->inserted; i++)
3600 list_del(&rxfer->inserted_transfers[i].transfer_list);
3604 * spi_replace_transfers - replace transfers with several transfers
3605 * and register change with spi_message.resources
3606 * @msg: the spi_message we work upon
3607 * @xfer_first: the first spi_transfer we want to replace
3608 * @remove: number of transfers to remove
3609 * @insert: the number of transfers we want to insert instead
3610 * @release: extra release code necessary in some circumstances
3611 * @extradatasize: extra data to allocate (with alignment guarantees
3612 * of struct @spi_transfer)
3615 * Returns: pointer to @spi_replaced_transfers,
3616 * PTR_ERR(...) in case of errors.
3618 static struct spi_replaced_transfers *spi_replace_transfers(
3619 struct spi_message *msg,
3620 struct spi_transfer *xfer_first,
3623 spi_replaced_release_t release,
3624 size_t extradatasize,
3627 struct spi_replaced_transfers *rxfer;
3628 struct spi_transfer *xfer;
3631 /* Allocate the structure using spi_res */
3632 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
3633 struct_size(rxfer, inserted_transfers, insert)
3637 return ERR_PTR(-ENOMEM);
3639 /* The release code to invoke before running the generic release */
3640 rxfer->release = release;
3642 /* Assign extradata */
3645 &rxfer->inserted_transfers[insert];
3647 /* Init the replaced_transfers list */
3648 INIT_LIST_HEAD(&rxfer->replaced_transfers);
3651 * Assign the list_entry after which we should reinsert
3652 * the @replaced_transfers - it may be spi_message.messages!
3654 rxfer->replaced_after = xfer_first->transfer_list.prev;
3656 /* Remove the requested number of transfers */
3657 for (i = 0; i < remove; i++) {
3659 * If the entry after replaced_after it is msg->transfers
3660 * then we have been requested to remove more transfers
3661 * than are in the list.
3663 if (rxfer->replaced_after->next == &msg->transfers) {
3664 dev_err(&msg->spi->dev,
3665 "requested to remove more spi_transfers than are available\n");
3666 /* Insert replaced transfers back into the message */
3667 list_splice(&rxfer->replaced_transfers,
3668 rxfer->replaced_after);
3670 /* Free the spi_replace_transfer structure... */
3671 spi_res_free(rxfer);
3673 /* ...and return with an error */
3674 return ERR_PTR(-EINVAL);
3678 * Remove the entry after replaced_after from list of
3679 * transfers and add it to list of replaced_transfers.
3681 list_move_tail(rxfer->replaced_after->next,
3682 &rxfer->replaced_transfers);
3686 * Create copy of the given xfer with identical settings
3687 * based on the first transfer to get removed.
3689 for (i = 0; i < insert; i++) {
3690 /* We need to run in reverse order */
3691 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3693 /* Copy all spi_transfer data */
3694 memcpy(xfer, xfer_first, sizeof(*xfer));
3697 list_add(&xfer->transfer_list, rxfer->replaced_after);
3699 /* Clear cs_change and delay for all but the last */
3701 xfer->cs_change = false;
3702 xfer->delay.value = 0;
3706 /* Set up inserted... */
3707 rxfer->inserted = insert;
3709 /* ...and register it with spi_res/spi_message */
3710 spi_res_add(msg, rxfer);
3715 static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3716 struct spi_message *msg,
3717 struct spi_transfer **xferp,
3721 struct spi_transfer *xfer = *xferp, *xfers;
3722 struct spi_replaced_transfers *srt;
3726 /* Calculate how many we have to replace */
3727 count = DIV_ROUND_UP(xfer->len, maxsize);
3729 /* Create replacement */
3730 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
3732 return PTR_ERR(srt);
3733 xfers = srt->inserted_transfers;
3736 * Now handle each of those newly inserted spi_transfers.
3737 * Note that the replacements spi_transfers all are preset
3738 * to the same values as *xferp, so tx_buf, rx_buf and len
3739 * are all identical (as well as most others)
3740 * so we just have to fix up len and the pointers.
3742 * This also includes support for the depreciated
3743 * spi_message.is_dma_mapped interface.
3747 * The first transfer just needs the length modified, so we
3748 * run it outside the loop.
3750 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3752 /* All the others need rx_buf/tx_buf also set */
3753 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3754 /* Update rx_buf, tx_buf and DMA */
3755 if (xfers[i].rx_buf)
3756 xfers[i].rx_buf += offset;
3757 if (xfers[i].rx_dma)
3758 xfers[i].rx_dma += offset;
3759 if (xfers[i].tx_buf)
3760 xfers[i].tx_buf += offset;
3761 if (xfers[i].tx_dma)
3762 xfers[i].tx_dma += offset;
3765 xfers[i].len = min(maxsize, xfers[i].len - offset);
3769 * We set up xferp to the last entry we have inserted,
3770 * so that we skip those already split transfers.
3772 *xferp = &xfers[count - 1];
3774 /* Increment statistics counters */
3775 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics,
3776 transfers_split_maxsize);
3777 SPI_STATISTICS_INCREMENT_FIELD(msg->spi->pcpu_statistics,
3778 transfers_split_maxsize);
3784 * spi_split_transfers_maxsize - split spi transfers into multiple transfers
3785 * when an individual transfer exceeds a
3787 * @ctlr: the @spi_controller for this transfer
3788 * @msg: the @spi_message to transform
3789 * @maxsize: the maximum when to apply this
3790 * @gfp: GFP allocation flags
3792 * Return: status of transformation
3794 int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3795 struct spi_message *msg,
3799 struct spi_transfer *xfer;
3803 * Iterate over the transfer_list,
3804 * but note that xfer is advanced to the last transfer inserted
3805 * to avoid checking sizes again unnecessarily (also xfer does
3806 * potentially belong to a different list by the time the
3807 * replacement has happened).
3809 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3810 if (xfer->len > maxsize) {
3811 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3820 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3824 * spi_split_transfers_maxwords - split SPI transfers into multiple transfers
3825 * when an individual transfer exceeds a
3826 * certain number of SPI words
3827 * @ctlr: the @spi_controller for this transfer
3828 * @msg: the @spi_message to transform
3829 * @maxwords: the number of words to limit each transfer to
3830 * @gfp: GFP allocation flags
3832 * Return: status of transformation
3834 int spi_split_transfers_maxwords(struct spi_controller *ctlr,
3835 struct spi_message *msg,
3839 struct spi_transfer *xfer;
3842 * Iterate over the transfer_list,
3843 * but note that xfer is advanced to the last transfer inserted
3844 * to avoid checking sizes again unnecessarily (also xfer does
3845 * potentially belong to a different list by the time the
3846 * replacement has happened).
3848 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3852 maxsize = maxwords * roundup_pow_of_two(BITS_TO_BYTES(xfer->bits_per_word));
3853 if (xfer->len > maxsize) {
3854 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3863 EXPORT_SYMBOL_GPL(spi_split_transfers_maxwords);
3865 /*-------------------------------------------------------------------------*/
3868 * Core methods for SPI controller protocol drivers. Some of the
3869 * other core methods are currently defined as inline functions.
3872 static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3875 if (ctlr->bits_per_word_mask) {
3876 /* Only 32 bits fit in the mask */
3877 if (bits_per_word > 32)
3879 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3887 * spi_set_cs_timing - configure CS setup, hold, and inactive delays
3888 * @spi: the device that requires specific CS timing configuration
3890 * Return: zero on success, else a negative error code.
3892 static int spi_set_cs_timing(struct spi_device *spi)
3894 struct device *parent = spi->controller->dev.parent;
3897 if (spi->controller->set_cs_timing && !spi_get_csgpiod(spi, 0)) {
3898 if (spi->controller->auto_runtime_pm) {
3899 status = pm_runtime_get_sync(parent);
3901 pm_runtime_put_noidle(parent);
3902 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3907 status = spi->controller->set_cs_timing(spi);
3908 pm_runtime_mark_last_busy(parent);
3909 pm_runtime_put_autosuspend(parent);
3911 status = spi->controller->set_cs_timing(spi);
3918 * spi_setup - setup SPI mode and clock rate
3919 * @spi: the device whose settings are being modified
3920 * Context: can sleep, and no requests are queued to the device
3922 * SPI protocol drivers may need to update the transfer mode if the
3923 * device doesn't work with its default. They may likewise need
3924 * to update clock rates or word sizes from initial values. This function
3925 * changes those settings, and must be called from a context that can sleep.
3926 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3927 * effect the next time the device is selected and data is transferred to
3928 * or from it. When this function returns, the SPI device is deselected.
3930 * Note that this call will fail if the protocol driver specifies an option
3931 * that the underlying controller or its driver does not support. For
3932 * example, not all hardware supports wire transfers using nine bit words,
3933 * LSB-first wire encoding, or active-high chipselects.
3935 * Return: zero on success, else a negative error code.
3937 int spi_setup(struct spi_device *spi)
3939 unsigned bad_bits, ugly_bits;
3943 * Check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
3944 * are set at the same time.
3946 if ((hweight_long(spi->mode &
3947 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
3948 (hweight_long(spi->mode &
3949 (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
3951 "setup: can not select any two of dual, quad and no-rx/tx at the same time\n");
3954 /* If it is SPI_3WIRE mode, DUAL and QUAD should be forbidden */
3955 if ((spi->mode & SPI_3WIRE) && (spi->mode &
3956 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3957 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3960 * Help drivers fail *cleanly* when they need options
3961 * that aren't supported with their current controller.
3962 * SPI_CS_WORD has a fallback software implementation,
3963 * so it is ignored here.
3965 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
3966 SPI_NO_TX | SPI_NO_RX);
3967 ugly_bits = bad_bits &
3968 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3969 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3972 "setup: ignoring unsupported mode bits %x\n",
3974 spi->mode &= ~ugly_bits;
3975 bad_bits &= ~ugly_bits;
3978 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3983 if (!spi->bits_per_word) {
3984 spi->bits_per_word = 8;
3987 * Some controllers may not support the default 8 bits-per-word
3988 * so only perform the check when this is explicitly provided.
3990 status = __spi_validate_bits_per_word(spi->controller,
3991 spi->bits_per_word);
3996 if (spi->controller->max_speed_hz &&
3997 (!spi->max_speed_hz ||
3998 spi->max_speed_hz > spi->controller->max_speed_hz))
3999 spi->max_speed_hz = spi->controller->max_speed_hz;
4001 mutex_lock(&spi->controller->io_mutex);
4003 if (spi->controller->setup) {
4004 status = spi->controller->setup(spi);
4006 mutex_unlock(&spi->controller->io_mutex);
4007 dev_err(&spi->controller->dev, "Failed to setup device: %d\n",
4013 status = spi_set_cs_timing(spi);
4015 mutex_unlock(&spi->controller->io_mutex);
4019 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
4020 status = pm_runtime_resume_and_get(spi->controller->dev.parent);
4022 mutex_unlock(&spi->controller->io_mutex);
4023 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
4029 * We do not want to return positive value from pm_runtime_get,
4030 * there are many instances of devices calling spi_setup() and
4031 * checking for a non-zero return value instead of a negative
4036 spi_set_cs(spi, false, true);
4037 pm_runtime_mark_last_busy(spi->controller->dev.parent);
4038 pm_runtime_put_autosuspend(spi->controller->dev.parent);
4040 spi_set_cs(spi, false, true);
4043 mutex_unlock(&spi->controller->io_mutex);
4045 if (spi->rt && !spi->controller->rt) {
4046 spi->controller->rt = true;
4047 spi_set_thread_rt(spi->controller);
4050 trace_spi_setup(spi, status);
4052 dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
4053 spi->mode & SPI_MODE_X_MASK,
4054 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
4055 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
4056 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
4057 (spi->mode & SPI_LOOP) ? "loopback, " : "",
4058 spi->bits_per_word, spi->max_speed_hz,
4063 EXPORT_SYMBOL_GPL(spi_setup);
4065 static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
4066 struct spi_device *spi)
4070 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
4074 delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
4078 if (delay1 < delay2)
4079 memcpy(&xfer->word_delay, &spi->word_delay,
4080 sizeof(xfer->word_delay));
4085 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
4087 struct spi_controller *ctlr = spi->controller;
4088 struct spi_transfer *xfer;
4091 if (list_empty(&message->transfers))
4097 * Half-duplex links include original MicroWire, and ones with
4098 * only one data pin like SPI_3WIRE (switches direction) or where
4099 * either MOSI or MISO is missing. They can also be caused by
4100 * software limitations.
4102 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
4103 (spi->mode & SPI_3WIRE)) {
4104 unsigned flags = ctlr->flags;
4106 list_for_each_entry(xfer, &message->transfers, transfer_list) {
4107 if (xfer->rx_buf && xfer->tx_buf)
4109 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
4111 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
4117 * Set transfer bits_per_word and max speed as spi device default if
4118 * it is not set for this transfer.
4119 * Set transfer tx_nbits and rx_nbits as single transfer default
4120 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
4121 * Ensure transfer word_delay is at least as long as that required by
4124 message->frame_length = 0;
4125 list_for_each_entry(xfer, &message->transfers, transfer_list) {
4126 xfer->effective_speed_hz = 0;
4127 message->frame_length += xfer->len;
4128 if (!xfer->bits_per_word)
4129 xfer->bits_per_word = spi->bits_per_word;
4131 if (!xfer->speed_hz)
4132 xfer->speed_hz = spi->max_speed_hz;
4134 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
4135 xfer->speed_hz = ctlr->max_speed_hz;
4137 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
4141 * SPI transfer length should be multiple of SPI word size
4142 * where SPI word size should be power-of-two multiple.
4144 if (xfer->bits_per_word <= 8)
4146 else if (xfer->bits_per_word <= 16)
4151 /* No partial transfers accepted */
4152 if (xfer->len % w_size)
4155 if (xfer->speed_hz && ctlr->min_speed_hz &&
4156 xfer->speed_hz < ctlr->min_speed_hz)
4159 if (xfer->tx_buf && !xfer->tx_nbits)
4160 xfer->tx_nbits = SPI_NBITS_SINGLE;
4161 if (xfer->rx_buf && !xfer->rx_nbits)
4162 xfer->rx_nbits = SPI_NBITS_SINGLE;
4164 * Check transfer tx/rx_nbits:
4165 * 1. check the value matches one of single, dual and quad
4166 * 2. check tx/rx_nbits match the mode in spi_device
4169 if (spi->mode & SPI_NO_TX)
4171 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
4172 xfer->tx_nbits != SPI_NBITS_DUAL &&
4173 xfer->tx_nbits != SPI_NBITS_QUAD)
4175 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
4176 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
4178 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
4179 !(spi->mode & SPI_TX_QUAD))
4182 /* Check transfer rx_nbits */
4184 if (spi->mode & SPI_NO_RX)
4186 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
4187 xfer->rx_nbits != SPI_NBITS_DUAL &&
4188 xfer->rx_nbits != SPI_NBITS_QUAD)
4190 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
4191 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
4193 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
4194 !(spi->mode & SPI_RX_QUAD))
4198 if (_spi_xfer_word_delay_update(xfer, spi))
4202 message->status = -EINPROGRESS;
4207 static int __spi_async(struct spi_device *spi, struct spi_message *message)
4209 struct spi_controller *ctlr = spi->controller;
4210 struct spi_transfer *xfer;
4213 * Some controllers do not support doing regular SPI transfers. Return
4214 * ENOTSUPP when this is the case.
4216 if (!ctlr->transfer)
4219 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_async);
4220 SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_async);
4222 trace_spi_message_submit(message);
4224 if (!ctlr->ptp_sts_supported) {
4225 list_for_each_entry(xfer, &message->transfers, transfer_list) {
4226 xfer->ptp_sts_word_pre = 0;
4227 ptp_read_system_prets(xfer->ptp_sts);
4231 return ctlr->transfer(spi, message);
4235 * spi_async - asynchronous SPI transfer
4236 * @spi: device with which data will be exchanged
4237 * @message: describes the data transfers, including completion callback
4238 * Context: any (IRQs may be blocked, etc)
4240 * This call may be used in_irq and other contexts which can't sleep,
4241 * as well as from task contexts which can sleep.
4243 * The completion callback is invoked in a context which can't sleep.
4244 * Before that invocation, the value of message->status is undefined.
4245 * When the callback is issued, message->status holds either zero (to
4246 * indicate complete success) or a negative error code. After that
4247 * callback returns, the driver which issued the transfer request may
4248 * deallocate the associated memory; it's no longer in use by any SPI
4249 * core or controller driver code.
4251 * Note that although all messages to a spi_device are handled in
4252 * FIFO order, messages may go to different devices in other orders.
4253 * Some device might be higher priority, or have various "hard" access
4254 * time requirements, for example.
4256 * On detection of any fault during the transfer, processing of
4257 * the entire message is aborted, and the device is deselected.
4258 * Until returning from the associated message completion callback,
4259 * no other spi_message queued to that device will be processed.
4260 * (This rule applies equally to all the synchronous transfer calls,
4261 * which are wrappers around this core asynchronous primitive.)
4263 * Return: zero on success, else a negative error code.
4265 int spi_async(struct spi_device *spi, struct spi_message *message)
4267 struct spi_controller *ctlr = spi->controller;
4269 unsigned long flags;
4271 ret = __spi_validate(spi, message);
4275 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
4277 if (ctlr->bus_lock_flag)
4280 ret = __spi_async(spi, message);
4282 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
4286 EXPORT_SYMBOL_GPL(spi_async);
4289 * spi_async_locked - version of spi_async with exclusive bus usage
4290 * @spi: device with which data will be exchanged
4291 * @message: describes the data transfers, including completion callback
4292 * Context: any (IRQs may be blocked, etc)
4294 * This call may be used in_irq and other contexts which can't sleep,
4295 * as well as from task contexts which can sleep.
4297 * The completion callback is invoked in a context which can't sleep.
4298 * Before that invocation, the value of message->status is undefined.
4299 * When the callback is issued, message->status holds either zero (to
4300 * indicate complete success) or a negative error code. After that
4301 * callback returns, the driver which issued the transfer request may
4302 * deallocate the associated memory; it's no longer in use by any SPI
4303 * core or controller driver code.
4305 * Note that although all messages to a spi_device are handled in
4306 * FIFO order, messages may go to different devices in other orders.
4307 * Some device might be higher priority, or have various "hard" access
4308 * time requirements, for example.
4310 * On detection of any fault during the transfer, processing of
4311 * the entire message is aborted, and the device is deselected.
4312 * Until returning from the associated message completion callback,
4313 * no other spi_message queued to that device will be processed.
4314 * (This rule applies equally to all the synchronous transfer calls,
4315 * which are wrappers around this core asynchronous primitive.)
4317 * Return: zero on success, else a negative error code.
4319 static int spi_async_locked(struct spi_device *spi, struct spi_message *message)
4321 struct spi_controller *ctlr = spi->controller;
4323 unsigned long flags;
4325 ret = __spi_validate(spi, message);
4329 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
4331 ret = __spi_async(spi, message);
4333 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
4339 static void __spi_transfer_message_noqueue(struct spi_controller *ctlr, struct spi_message *msg)
4344 mutex_lock(&ctlr->io_mutex);
4346 was_busy = ctlr->busy;
4348 ctlr->cur_msg = msg;
4349 ret = __spi_pump_transfer_message(ctlr, msg, was_busy);
4351 dev_err(&ctlr->dev, "noqueue transfer failed\n");
4352 ctlr->cur_msg = NULL;
4353 ctlr->fallback = false;
4356 kfree(ctlr->dummy_rx);
4357 ctlr->dummy_rx = NULL;
4358 kfree(ctlr->dummy_tx);
4359 ctlr->dummy_tx = NULL;
4360 if (ctlr->unprepare_transfer_hardware &&
4361 ctlr->unprepare_transfer_hardware(ctlr))
4363 "failed to unprepare transfer hardware\n");
4364 spi_idle_runtime_pm(ctlr);
4367 mutex_unlock(&ctlr->io_mutex);
4370 /*-------------------------------------------------------------------------*/
4373 * Utility methods for SPI protocol drivers, layered on
4374 * top of the core. Some other utility methods are defined as
4378 static void spi_complete(void *arg)
4383 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
4385 DECLARE_COMPLETION_ONSTACK(done);
4387 struct spi_controller *ctlr = spi->controller;
4389 if (__spi_check_suspended(ctlr)) {
4390 dev_warn_once(&spi->dev, "Attempted to sync while suspend\n");
4394 status = __spi_validate(spi, message);
4398 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync);
4399 SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync);
4402 * Checking queue_empty here only guarantees async/sync message
4403 * ordering when coming from the same context. It does not need to
4404 * guard against reentrancy from a different context. The io_mutex
4405 * will catch those cases.
4407 if (READ_ONCE(ctlr->queue_empty) && !ctlr->must_async) {
4408 message->actual_length = 0;
4409 message->status = -EINPROGRESS;
4411 trace_spi_message_submit(message);
4413 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync_immediate);
4414 SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync_immediate);
4416 __spi_transfer_message_noqueue(ctlr, message);
4418 return message->status;
4422 * There are messages in the async queue that could have originated
4423 * from the same context, so we need to preserve ordering.
4424 * Therefor we send the message to the async queue and wait until they
4427 message->complete = spi_complete;
4428 message->context = &done;
4429 status = spi_async_locked(spi, message);
4431 wait_for_completion(&done);
4432 status = message->status;
4434 message->context = NULL;
4440 * spi_sync - blocking/synchronous SPI data transfers
4441 * @spi: device with which data will be exchanged
4442 * @message: describes the data transfers
4443 * Context: can sleep
4445 * This call may only be used from a context that may sleep. The sleep
4446 * is non-interruptible, and has no timeout. Low-overhead controller
4447 * drivers may DMA directly into and out of the message buffers.
4449 * Note that the SPI device's chip select is active during the message,
4450 * and then is normally disabled between messages. Drivers for some
4451 * frequently-used devices may want to minimize costs of selecting a chip,
4452 * by leaving it selected in anticipation that the next message will go
4453 * to the same chip. (That may increase power usage.)
4455 * Also, the caller is guaranteeing that the memory associated with the
4456 * message will not be freed before this call returns.
4458 * Return: zero on success, else a negative error code.
4460 int spi_sync(struct spi_device *spi, struct spi_message *message)
4464 mutex_lock(&spi->controller->bus_lock_mutex);
4465 ret = __spi_sync(spi, message);
4466 mutex_unlock(&spi->controller->bus_lock_mutex);
4470 EXPORT_SYMBOL_GPL(spi_sync);
4473 * spi_sync_locked - version of spi_sync with exclusive bus usage
4474 * @spi: device with which data will be exchanged
4475 * @message: describes the data transfers
4476 * Context: can sleep
4478 * This call may only be used from a context that may sleep. The sleep
4479 * is non-interruptible, and has no timeout. Low-overhead controller
4480 * drivers may DMA directly into and out of the message buffers.
4482 * This call should be used by drivers that require exclusive access to the
4483 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
4484 * be released by a spi_bus_unlock call when the exclusive access is over.
4486 * Return: zero on success, else a negative error code.
4488 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
4490 return __spi_sync(spi, message);
4492 EXPORT_SYMBOL_GPL(spi_sync_locked);
4495 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
4496 * @ctlr: SPI bus master that should be locked for exclusive bus access
4497 * Context: can sleep
4499 * This call may only be used from a context that may sleep. The sleep
4500 * is non-interruptible, and has no timeout.
4502 * This call should be used by drivers that require exclusive access to the
4503 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
4504 * exclusive access is over. Data transfer must be done by spi_sync_locked
4505 * and spi_async_locked calls when the SPI bus lock is held.
4507 * Return: always zero.
4509 int spi_bus_lock(struct spi_controller *ctlr)
4511 unsigned long flags;
4513 mutex_lock(&ctlr->bus_lock_mutex);
4515 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
4516 ctlr->bus_lock_flag = 1;
4517 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
4519 /* Mutex remains locked until spi_bus_unlock() is called */
4523 EXPORT_SYMBOL_GPL(spi_bus_lock);
4526 * spi_bus_unlock - release the lock for exclusive SPI bus usage
4527 * @ctlr: SPI bus master that was locked for exclusive bus access
4528 * Context: can sleep
4530 * This call may only be used from a context that may sleep. The sleep
4531 * is non-interruptible, and has no timeout.
4533 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
4536 * Return: always zero.
4538 int spi_bus_unlock(struct spi_controller *ctlr)
4540 ctlr->bus_lock_flag = 0;
4542 mutex_unlock(&ctlr->bus_lock_mutex);
4546 EXPORT_SYMBOL_GPL(spi_bus_unlock);
4548 /* Portable code must never pass more than 32 bytes */
4549 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
4554 * spi_write_then_read - SPI synchronous write followed by read
4555 * @spi: device with which data will be exchanged
4556 * @txbuf: data to be written (need not be DMA-safe)
4557 * @n_tx: size of txbuf, in bytes
4558 * @rxbuf: buffer into which data will be read (need not be DMA-safe)
4559 * @n_rx: size of rxbuf, in bytes
4560 * Context: can sleep
4562 * This performs a half duplex MicroWire style transaction with the
4563 * device, sending txbuf and then reading rxbuf. The return value
4564 * is zero for success, else a negative errno status code.
4565 * This call may only be used from a context that may sleep.
4567 * Parameters to this routine are always copied using a small buffer.
4568 * Performance-sensitive or bulk transfer code should instead use
4569 * spi_{async,sync}() calls with DMA-safe buffers.
4571 * Return: zero on success, else a negative error code.
4573 int spi_write_then_read(struct spi_device *spi,
4574 const void *txbuf, unsigned n_tx,
4575 void *rxbuf, unsigned n_rx)
4577 static DEFINE_MUTEX(lock);
4580 struct spi_message message;
4581 struct spi_transfer x[2];
4585 * Use preallocated DMA-safe buffer if we can. We can't avoid
4586 * copying here, (as a pure convenience thing), but we can
4587 * keep heap costs out of the hot path unless someone else is
4588 * using the pre-allocated buffer or the transfer is too large.
4590 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
4591 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
4592 GFP_KERNEL | GFP_DMA);
4599 spi_message_init(&message);
4600 memset(x, 0, sizeof(x));
4603 spi_message_add_tail(&x[0], &message);
4607 spi_message_add_tail(&x[1], &message);
4610 memcpy(local_buf, txbuf, n_tx);
4611 x[0].tx_buf = local_buf;
4612 x[1].rx_buf = local_buf + n_tx;
4615 status = spi_sync(spi, &message);
4617 memcpy(rxbuf, x[1].rx_buf, n_rx);
4619 if (x[0].tx_buf == buf)
4620 mutex_unlock(&lock);
4626 EXPORT_SYMBOL_GPL(spi_write_then_read);
4628 /*-------------------------------------------------------------------------*/
4630 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
4631 /* Must call put_device() when done with returned spi_device device */
4632 static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
4634 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
4636 return dev ? to_spi_device(dev) : NULL;
4639 /* The spi controllers are not using spi_bus, so we find it with another way */
4640 static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
4644 dev = class_find_device_by_of_node(&spi_master_class, node);
4645 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4646 dev = class_find_device_by_of_node(&spi_slave_class, node);
4650 /* Reference got in class_find_device */
4651 return container_of(dev, struct spi_controller, dev);
4654 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
4657 struct of_reconfig_data *rd = arg;
4658 struct spi_controller *ctlr;
4659 struct spi_device *spi;
4661 switch (of_reconfig_get_state_change(action, arg)) {
4662 case OF_RECONFIG_CHANGE_ADD:
4663 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
4665 return NOTIFY_OK; /* Not for us */
4667 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
4668 put_device(&ctlr->dev);
4673 * Clear the flag before adding the device so that fw_devlink
4674 * doesn't skip adding consumers to this device.
4676 rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
4677 spi = of_register_spi_device(ctlr, rd->dn);
4678 put_device(&ctlr->dev);
4681 pr_err("%s: failed to create for '%pOF'\n",
4683 of_node_clear_flag(rd->dn, OF_POPULATED);
4684 return notifier_from_errno(PTR_ERR(spi));
4688 case OF_RECONFIG_CHANGE_REMOVE:
4689 /* Already depopulated? */
4690 if (!of_node_check_flag(rd->dn, OF_POPULATED))
4693 /* Find our device by node */
4694 spi = of_find_spi_device_by_node(rd->dn);
4696 return NOTIFY_OK; /* No? not meant for us */
4698 /* Unregister takes one ref away */
4699 spi_unregister_device(spi);
4701 /* And put the reference of the find */
4702 put_device(&spi->dev);
4709 static struct notifier_block spi_of_notifier = {
4710 .notifier_call = of_spi_notify,
4712 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4713 extern struct notifier_block spi_of_notifier;
4714 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4716 #if IS_ENABLED(CONFIG_ACPI)
4717 static int spi_acpi_controller_match(struct device *dev, const void *data)
4719 return ACPI_COMPANION(dev->parent) == data;
4722 struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4726 dev = class_find_device(&spi_master_class, NULL, adev,
4727 spi_acpi_controller_match);
4728 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4729 dev = class_find_device(&spi_slave_class, NULL, adev,
4730 spi_acpi_controller_match);
4734 return container_of(dev, struct spi_controller, dev);
4736 EXPORT_SYMBOL_GPL(acpi_spi_find_controller_by_adev);
4738 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4742 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4743 return to_spi_device(dev);
4746 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4749 struct acpi_device *adev = arg;
4750 struct spi_controller *ctlr;
4751 struct spi_device *spi;
4754 case ACPI_RECONFIG_DEVICE_ADD:
4755 ctlr = acpi_spi_find_controller_by_adev(acpi_dev_parent(adev));
4759 acpi_register_spi_device(ctlr, adev);
4760 put_device(&ctlr->dev);
4762 case ACPI_RECONFIG_DEVICE_REMOVE:
4763 if (!acpi_device_enumerated(adev))
4766 spi = acpi_spi_find_device_by_adev(adev);
4770 spi_unregister_device(spi);
4771 put_device(&spi->dev);
4778 static struct notifier_block spi_acpi_notifier = {
4779 .notifier_call = acpi_spi_notify,
4782 extern struct notifier_block spi_acpi_notifier;
4785 static int __init spi_init(void)
4789 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4795 status = bus_register(&spi_bus_type);
4799 status = class_register(&spi_master_class);
4803 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4804 status = class_register(&spi_slave_class);
4809 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4810 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4811 if (IS_ENABLED(CONFIG_ACPI))
4812 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4817 class_unregister(&spi_master_class);
4819 bus_unregister(&spi_bus_type);
4828 * A board_info is normally registered in arch_initcall(),
4829 * but even essential drivers wait till later.
4831 * REVISIT only boardinfo really needs static linking. The rest (device and
4832 * driver registration) _could_ be dynamically linked (modular) ... Costs
4833 * include needing to have boardinfo data structures be much more public.
4835 postcore_initcall(spi_init);