1 // SPDX-License-Identifier: GPL-2.0-or-later
4 // Copyright (C) 2005 David Brownell
5 // Copyright (C) 2008 Secret Lab Technologies Ltd.
7 #include <linux/kernel.h>
8 #include <linux/device.h>
9 #include <linux/init.h>
10 #include <linux/cache.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/dmaengine.h>
13 #include <linux/mutex.h>
14 #include <linux/of_device.h>
15 #include <linux/of_irq.h>
16 #include <linux/clk/clk-conf.h>
17 #include <linux/slab.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/spi/spi.h>
20 #include <linux/spi/spi-mem.h>
21 #include <linux/of_gpio.h>
22 #include <linux/gpio/consumer.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/pm_domain.h>
25 #include <linux/property.h>
26 #include <linux/export.h>
27 #include <linux/sched/rt.h>
28 #include <uapi/linux/sched/types.h>
29 #include <linux/delay.h>
30 #include <linux/kthread.h>
31 #include <linux/ioport.h>
32 #include <linux/acpi.h>
33 #include <linux/highmem.h>
34 #include <linux/idr.h>
35 #include <linux/platform_data/x86/apple.h>
37 #define CREATE_TRACE_POINTS
38 #include <trace/events/spi.h>
39 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start);
40 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop);
42 #include "internals.h"
44 static DEFINE_IDR(spi_master_idr);
46 static void spidev_release(struct device *dev)
48 struct spi_device *spi = to_spi_device(dev);
50 spi_controller_put(spi->controller);
51 kfree(spi->driver_override);
56 modalias_show(struct device *dev, struct device_attribute *a, char *buf)
58 const struct spi_device *spi = to_spi_device(dev);
61 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
65 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
67 static DEVICE_ATTR_RO(modalias);
69 static ssize_t driver_override_store(struct device *dev,
70 struct device_attribute *a,
71 const char *buf, size_t count)
73 struct spi_device *spi = to_spi_device(dev);
74 const char *end = memchr(buf, '\n', count);
75 const size_t len = end ? end - buf : count;
76 const char *driver_override, *old;
78 /* We need to keep extra room for a newline when displaying value */
79 if (len >= (PAGE_SIZE - 1))
82 driver_override = kstrndup(buf, len, GFP_KERNEL);
87 old = spi->driver_override;
89 spi->driver_override = driver_override;
91 /* Empty string, disable driver override */
92 spi->driver_override = NULL;
93 kfree(driver_override);
101 static ssize_t driver_override_show(struct device *dev,
102 struct device_attribute *a, char *buf)
104 const struct spi_device *spi = to_spi_device(dev);
108 len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
112 static DEVICE_ATTR_RW(driver_override);
114 #define SPI_STATISTICS_ATTRS(field, file) \
115 static ssize_t spi_controller_##field##_show(struct device *dev, \
116 struct device_attribute *attr, \
119 struct spi_controller *ctlr = container_of(dev, \
120 struct spi_controller, dev); \
121 return spi_statistics_##field##_show(&ctlr->statistics, buf); \
123 static struct device_attribute dev_attr_spi_controller_##field = { \
124 .attr = { .name = file, .mode = 0444 }, \
125 .show = spi_controller_##field##_show, \
127 static ssize_t spi_device_##field##_show(struct device *dev, \
128 struct device_attribute *attr, \
131 struct spi_device *spi = to_spi_device(dev); \
132 return spi_statistics_##field##_show(&spi->statistics, buf); \
134 static struct device_attribute dev_attr_spi_device_##field = { \
135 .attr = { .name = file, .mode = 0444 }, \
136 .show = spi_device_##field##_show, \
139 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
140 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
143 unsigned long flags; \
145 spin_lock_irqsave(&stat->lock, flags); \
146 len = sprintf(buf, format_string, stat->field); \
147 spin_unlock_irqrestore(&stat->lock, flags); \
150 SPI_STATISTICS_ATTRS(name, file)
152 #define SPI_STATISTICS_SHOW(field, format_string) \
153 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
154 field, format_string)
156 SPI_STATISTICS_SHOW(messages, "%lu");
157 SPI_STATISTICS_SHOW(transfers, "%lu");
158 SPI_STATISTICS_SHOW(errors, "%lu");
159 SPI_STATISTICS_SHOW(timedout, "%lu");
161 SPI_STATISTICS_SHOW(spi_sync, "%lu");
162 SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
163 SPI_STATISTICS_SHOW(spi_async, "%lu");
165 SPI_STATISTICS_SHOW(bytes, "%llu");
166 SPI_STATISTICS_SHOW(bytes_rx, "%llu");
167 SPI_STATISTICS_SHOW(bytes_tx, "%llu");
169 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
170 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
171 "transfer_bytes_histo_" number, \
172 transfer_bytes_histo[index], "%lu")
173 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
174 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
175 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
176 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
177 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
178 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
179 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
180 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
181 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
182 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
183 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
184 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
185 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
186 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
187 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
188 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
189 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
191 SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
193 static struct attribute *spi_dev_attrs[] = {
194 &dev_attr_modalias.attr,
195 &dev_attr_driver_override.attr,
199 static const struct attribute_group spi_dev_group = {
200 .attrs = spi_dev_attrs,
203 static struct attribute *spi_device_statistics_attrs[] = {
204 &dev_attr_spi_device_messages.attr,
205 &dev_attr_spi_device_transfers.attr,
206 &dev_attr_spi_device_errors.attr,
207 &dev_attr_spi_device_timedout.attr,
208 &dev_attr_spi_device_spi_sync.attr,
209 &dev_attr_spi_device_spi_sync_immediate.attr,
210 &dev_attr_spi_device_spi_async.attr,
211 &dev_attr_spi_device_bytes.attr,
212 &dev_attr_spi_device_bytes_rx.attr,
213 &dev_attr_spi_device_bytes_tx.attr,
214 &dev_attr_spi_device_transfer_bytes_histo0.attr,
215 &dev_attr_spi_device_transfer_bytes_histo1.attr,
216 &dev_attr_spi_device_transfer_bytes_histo2.attr,
217 &dev_attr_spi_device_transfer_bytes_histo3.attr,
218 &dev_attr_spi_device_transfer_bytes_histo4.attr,
219 &dev_attr_spi_device_transfer_bytes_histo5.attr,
220 &dev_attr_spi_device_transfer_bytes_histo6.attr,
221 &dev_attr_spi_device_transfer_bytes_histo7.attr,
222 &dev_attr_spi_device_transfer_bytes_histo8.attr,
223 &dev_attr_spi_device_transfer_bytes_histo9.attr,
224 &dev_attr_spi_device_transfer_bytes_histo10.attr,
225 &dev_attr_spi_device_transfer_bytes_histo11.attr,
226 &dev_attr_spi_device_transfer_bytes_histo12.attr,
227 &dev_attr_spi_device_transfer_bytes_histo13.attr,
228 &dev_attr_spi_device_transfer_bytes_histo14.attr,
229 &dev_attr_spi_device_transfer_bytes_histo15.attr,
230 &dev_attr_spi_device_transfer_bytes_histo16.attr,
231 &dev_attr_spi_device_transfers_split_maxsize.attr,
235 static const struct attribute_group spi_device_statistics_group = {
236 .name = "statistics",
237 .attrs = spi_device_statistics_attrs,
240 static const struct attribute_group *spi_dev_groups[] = {
242 &spi_device_statistics_group,
246 static struct attribute *spi_controller_statistics_attrs[] = {
247 &dev_attr_spi_controller_messages.attr,
248 &dev_attr_spi_controller_transfers.attr,
249 &dev_attr_spi_controller_errors.attr,
250 &dev_attr_spi_controller_timedout.attr,
251 &dev_attr_spi_controller_spi_sync.attr,
252 &dev_attr_spi_controller_spi_sync_immediate.attr,
253 &dev_attr_spi_controller_spi_async.attr,
254 &dev_attr_spi_controller_bytes.attr,
255 &dev_attr_spi_controller_bytes_rx.attr,
256 &dev_attr_spi_controller_bytes_tx.attr,
257 &dev_attr_spi_controller_transfer_bytes_histo0.attr,
258 &dev_attr_spi_controller_transfer_bytes_histo1.attr,
259 &dev_attr_spi_controller_transfer_bytes_histo2.attr,
260 &dev_attr_spi_controller_transfer_bytes_histo3.attr,
261 &dev_attr_spi_controller_transfer_bytes_histo4.attr,
262 &dev_attr_spi_controller_transfer_bytes_histo5.attr,
263 &dev_attr_spi_controller_transfer_bytes_histo6.attr,
264 &dev_attr_spi_controller_transfer_bytes_histo7.attr,
265 &dev_attr_spi_controller_transfer_bytes_histo8.attr,
266 &dev_attr_spi_controller_transfer_bytes_histo9.attr,
267 &dev_attr_spi_controller_transfer_bytes_histo10.attr,
268 &dev_attr_spi_controller_transfer_bytes_histo11.attr,
269 &dev_attr_spi_controller_transfer_bytes_histo12.attr,
270 &dev_attr_spi_controller_transfer_bytes_histo13.attr,
271 &dev_attr_spi_controller_transfer_bytes_histo14.attr,
272 &dev_attr_spi_controller_transfer_bytes_histo15.attr,
273 &dev_attr_spi_controller_transfer_bytes_histo16.attr,
274 &dev_attr_spi_controller_transfers_split_maxsize.attr,
278 static const struct attribute_group spi_controller_statistics_group = {
279 .name = "statistics",
280 .attrs = spi_controller_statistics_attrs,
283 static const struct attribute_group *spi_master_groups[] = {
284 &spi_controller_statistics_group,
288 void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
289 struct spi_transfer *xfer,
290 struct spi_controller *ctlr)
293 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
298 spin_lock_irqsave(&stats->lock, flags);
301 stats->transfer_bytes_histo[l2len]++;
303 stats->bytes += xfer->len;
304 if ((xfer->tx_buf) &&
305 (xfer->tx_buf != ctlr->dummy_tx))
306 stats->bytes_tx += xfer->len;
307 if ((xfer->rx_buf) &&
308 (xfer->rx_buf != ctlr->dummy_rx))
309 stats->bytes_rx += xfer->len;
311 spin_unlock_irqrestore(&stats->lock, flags);
313 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
315 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
316 * and the sysfs version makes coldplug work too.
319 static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
320 const struct spi_device *sdev)
322 while (id->name[0]) {
323 if (!strcmp(sdev->modalias, id->name))
330 const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
332 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
334 return spi_match_id(sdrv->id_table, sdev);
336 EXPORT_SYMBOL_GPL(spi_get_device_id);
338 static int spi_match_device(struct device *dev, struct device_driver *drv)
340 const struct spi_device *spi = to_spi_device(dev);
341 const struct spi_driver *sdrv = to_spi_driver(drv);
343 /* Check override first, and if set, only use the named driver */
344 if (spi->driver_override)
345 return strcmp(spi->driver_override, drv->name) == 0;
347 /* Attempt an OF style match */
348 if (of_driver_match_device(dev, drv))
352 if (acpi_driver_match_device(dev, drv))
356 return !!spi_match_id(sdrv->id_table, spi);
358 return strcmp(spi->modalias, drv->name) == 0;
361 static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
363 const struct spi_device *spi = to_spi_device(dev);
366 rc = acpi_device_uevent_modalias(dev, env);
370 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
373 static int spi_probe(struct device *dev)
375 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
376 struct spi_device *spi = to_spi_device(dev);
379 ret = of_clk_set_defaults(dev->of_node, false);
384 spi->irq = of_irq_get(dev->of_node, 0);
385 if (spi->irq == -EPROBE_DEFER)
386 return -EPROBE_DEFER;
391 ret = dev_pm_domain_attach(dev, true);
396 ret = sdrv->probe(spi);
398 dev_pm_domain_detach(dev, true);
404 static int spi_remove(struct device *dev)
406 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
411 ret = sdrv->remove(to_spi_device(dev));
414 "Failed to unbind driver (%pe), ignoring\n",
418 dev_pm_domain_detach(dev, true);
423 static void spi_shutdown(struct device *dev)
426 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
429 sdrv->shutdown(to_spi_device(dev));
433 struct bus_type spi_bus_type = {
435 .dev_groups = spi_dev_groups,
436 .match = spi_match_device,
437 .uevent = spi_uevent,
439 .remove = spi_remove,
440 .shutdown = spi_shutdown,
442 EXPORT_SYMBOL_GPL(spi_bus_type);
445 * __spi_register_driver - register a SPI driver
446 * @owner: owner module of the driver to register
447 * @sdrv: the driver to register
450 * Return: zero on success, else a negative error code.
452 int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
454 sdrv->driver.owner = owner;
455 sdrv->driver.bus = &spi_bus_type;
456 return driver_register(&sdrv->driver);
458 EXPORT_SYMBOL_GPL(__spi_register_driver);
460 /*-------------------------------------------------------------------------*/
462 /* SPI devices should normally not be created by SPI device drivers; that
463 * would make them board-specific. Similarly with SPI controller drivers.
464 * Device registration normally goes into like arch/.../mach.../board-YYY.c
465 * with other readonly (flashable) information about mainboard devices.
469 struct list_head list;
470 struct spi_board_info board_info;
473 static LIST_HEAD(board_list);
474 static LIST_HEAD(spi_controller_list);
477 * Used to protect add/del operation for board_info list and
478 * spi_controller list, and their matching process
479 * also used to protect object of type struct idr
481 static DEFINE_MUTEX(board_lock);
484 * Prevents addition of devices with same chip select and
485 * addition of devices below an unregistering controller.
487 static DEFINE_MUTEX(spi_add_lock);
490 * spi_alloc_device - Allocate a new SPI device
491 * @ctlr: Controller to which device is connected
494 * Allows a driver to allocate and initialize a spi_device without
495 * registering it immediately. This allows a driver to directly
496 * fill the spi_device with device parameters before calling
497 * spi_add_device() on it.
499 * Caller is responsible to call spi_add_device() on the returned
500 * spi_device structure to add it to the SPI controller. If the caller
501 * needs to discard the spi_device without adding it, then it should
502 * call spi_dev_put() on it.
504 * Return: a pointer to the new device, or NULL.
506 struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
508 struct spi_device *spi;
510 if (!spi_controller_get(ctlr))
513 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
515 spi_controller_put(ctlr);
519 spi->master = spi->controller = ctlr;
520 spi->dev.parent = &ctlr->dev;
521 spi->dev.bus = &spi_bus_type;
522 spi->dev.release = spidev_release;
523 spi->cs_gpio = -ENOENT;
524 spi->mode = ctlr->buswidth_override_bits;
526 spin_lock_init(&spi->statistics.lock);
528 device_initialize(&spi->dev);
531 EXPORT_SYMBOL_GPL(spi_alloc_device);
533 static void spi_dev_set_name(struct spi_device *spi)
535 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
538 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
542 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
546 static int spi_dev_check(struct device *dev, void *data)
548 struct spi_device *spi = to_spi_device(dev);
549 struct spi_device *new_spi = data;
551 if (spi->controller == new_spi->controller &&
552 spi->chip_select == new_spi->chip_select)
557 static void spi_cleanup(struct spi_device *spi)
559 if (spi->controller->cleanup)
560 spi->controller->cleanup(spi);
564 * spi_add_device - Add spi_device allocated with spi_alloc_device
565 * @spi: spi_device to register
567 * Companion function to spi_alloc_device. Devices allocated with
568 * spi_alloc_device can be added onto the spi bus with this function.
570 * Return: 0 on success; negative errno on failure
572 int spi_add_device(struct spi_device *spi)
574 struct spi_controller *ctlr = spi->controller;
575 struct device *dev = ctlr->dev.parent;
578 /* Chipselects are numbered 0..max; validate. */
579 if (spi->chip_select >= ctlr->num_chipselect) {
580 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
581 ctlr->num_chipselect);
585 /* Set the bus ID string */
586 spi_dev_set_name(spi);
588 /* We need to make sure there's no other device with this
589 * chipselect **BEFORE** we call setup(), else we'll trash
590 * its configuration. Lock against concurrent add() calls.
592 mutex_lock(&spi_add_lock);
594 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
596 dev_err(dev, "chipselect %d already in use\n",
601 /* Controller may unregister concurrently */
602 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
603 !device_is_registered(&ctlr->dev)) {
608 /* Descriptors take precedence */
610 spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
611 else if (ctlr->cs_gpios)
612 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
614 /* Drivers may modify this initial i/o setup, but will
615 * normally rely on the device being setup. Devices
616 * using SPI_CS_HIGH can't coexist well otherwise...
618 status = spi_setup(spi);
620 dev_err(dev, "can't setup %s, status %d\n",
621 dev_name(&spi->dev), status);
625 /* Device may be bound to an active driver when this returns */
626 status = device_add(&spi->dev);
628 dev_err(dev, "can't add %s, status %d\n",
629 dev_name(&spi->dev), status);
632 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
636 mutex_unlock(&spi_add_lock);
639 EXPORT_SYMBOL_GPL(spi_add_device);
642 * spi_new_device - instantiate one new SPI device
643 * @ctlr: Controller to which device is connected
644 * @chip: Describes the SPI device
647 * On typical mainboards, this is purely internal; and it's not needed
648 * after board init creates the hard-wired devices. Some development
649 * platforms may not be able to use spi_register_board_info though, and
650 * this is exported so that for example a USB or parport based adapter
651 * driver could add devices (which it would learn about out-of-band).
653 * Return: the new device, or NULL.
655 struct spi_device *spi_new_device(struct spi_controller *ctlr,
656 struct spi_board_info *chip)
658 struct spi_device *proxy;
661 /* NOTE: caller did any chip->bus_num checks necessary.
663 * Also, unless we change the return value convention to use
664 * error-or-pointer (not NULL-or-pointer), troubleshootability
665 * suggests syslogged diagnostics are best here (ugh).
668 proxy = spi_alloc_device(ctlr);
672 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
674 proxy->chip_select = chip->chip_select;
675 proxy->max_speed_hz = chip->max_speed_hz;
676 proxy->mode = chip->mode;
677 proxy->irq = chip->irq;
678 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
679 proxy->dev.platform_data = (void *) chip->platform_data;
680 proxy->controller_data = chip->controller_data;
681 proxy->controller_state = NULL;
684 status = device_add_software_node(&proxy->dev, chip->swnode);
686 dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n",
687 chip->modalias, status);
692 status = spi_add_device(proxy);
699 device_remove_software_node(&proxy->dev);
703 EXPORT_SYMBOL_GPL(spi_new_device);
706 * spi_unregister_device - unregister a single SPI device
707 * @spi: spi_device to unregister
709 * Start making the passed SPI device vanish. Normally this would be handled
710 * by spi_unregister_controller().
712 void spi_unregister_device(struct spi_device *spi)
717 if (spi->dev.of_node) {
718 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
719 of_node_put(spi->dev.of_node);
721 if (ACPI_COMPANION(&spi->dev))
722 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
723 device_remove_software_node(&spi->dev);
724 device_del(&spi->dev);
726 put_device(&spi->dev);
728 EXPORT_SYMBOL_GPL(spi_unregister_device);
730 static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
731 struct spi_board_info *bi)
733 struct spi_device *dev;
735 if (ctlr->bus_num != bi->bus_num)
738 dev = spi_new_device(ctlr, bi);
740 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
745 * spi_register_board_info - register SPI devices for a given board
746 * @info: array of chip descriptors
747 * @n: how many descriptors are provided
750 * Board-specific early init code calls this (probably during arch_initcall)
751 * with segments of the SPI device table. Any device nodes are created later,
752 * after the relevant parent SPI controller (bus_num) is defined. We keep
753 * this table of devices forever, so that reloading a controller driver will
754 * not make Linux forget about these hard-wired devices.
756 * Other code can also call this, e.g. a particular add-on board might provide
757 * SPI devices through its expansion connector, so code initializing that board
758 * would naturally declare its SPI devices.
760 * The board info passed can safely be __initdata ... but be careful of
761 * any embedded pointers (platform_data, etc), they're copied as-is.
763 * Return: zero on success, else a negative error code.
765 int spi_register_board_info(struct spi_board_info const *info, unsigned n)
767 struct boardinfo *bi;
773 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
777 for (i = 0; i < n; i++, bi++, info++) {
778 struct spi_controller *ctlr;
780 memcpy(&bi->board_info, info, sizeof(*info));
782 mutex_lock(&board_lock);
783 list_add_tail(&bi->list, &board_list);
784 list_for_each_entry(ctlr, &spi_controller_list, list)
785 spi_match_controller_to_boardinfo(ctlr,
787 mutex_unlock(&board_lock);
793 /*-------------------------------------------------------------------------*/
795 static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
797 bool activate = enable;
800 * Avoid calling into the driver (or doing delays) if the chip select
801 * isn't actually changing from the last time this was called.
803 if (!force && (spi->controller->last_cs_enable == enable) &&
804 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
807 spi->controller->last_cs_enable = enable;
808 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
810 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
811 !spi->controller->set_cs_timing) {
813 spi_delay_exec(&spi->controller->cs_setup, NULL);
815 spi_delay_exec(&spi->controller->cs_hold, NULL);
818 if (spi->mode & SPI_CS_HIGH)
821 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
822 if (!(spi->mode & SPI_NO_CS)) {
825 * Historically ACPI has no means of the GPIO polarity and
826 * thus the SPISerialBus() resource defines it on the per-chip
827 * basis. In order to avoid a chain of negations, the GPIO
828 * polarity is considered being Active High. Even for the cases
829 * when _DSD() is involved (in the updated versions of ACPI)
830 * the GPIO CS polarity must be defined Active High to avoid
831 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
834 if (has_acpi_companion(&spi->dev))
835 gpiod_set_value_cansleep(spi->cs_gpiod, !enable);
837 /* Polarity handled by GPIO library */
838 gpiod_set_value_cansleep(spi->cs_gpiod, activate);
841 * invert the enable line, as active low is
844 gpio_set_value_cansleep(spi->cs_gpio, !enable);
847 /* Some SPI masters need both GPIO CS & slave_select */
848 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
849 spi->controller->set_cs)
850 spi->controller->set_cs(spi, !enable);
851 } else if (spi->controller->set_cs) {
852 spi->controller->set_cs(spi, !enable);
855 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
856 !spi->controller->set_cs_timing) {
858 spi_delay_exec(&spi->controller->cs_inactive, NULL);
862 #ifdef CONFIG_HAS_DMA
863 int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
864 struct sg_table *sgt, void *buf, size_t len,
865 enum dma_data_direction dir)
867 const bool vmalloced_buf = is_vmalloc_addr(buf);
868 unsigned int max_seg_size = dma_get_max_seg_size(dev);
869 #ifdef CONFIG_HIGHMEM
870 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
871 (unsigned long)buf < (PKMAP_BASE +
872 (LAST_PKMAP * PAGE_SIZE)));
874 const bool kmap_buf = false;
878 struct page *vm_page;
879 struct scatterlist *sg;
884 if (vmalloced_buf || kmap_buf) {
885 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
886 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
887 } else if (virt_addr_valid(buf)) {
888 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
889 sgs = DIV_ROUND_UP(len, desc_len);
894 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
899 for (i = 0; i < sgs; i++) {
901 if (vmalloced_buf || kmap_buf) {
903 * Next scatterlist entry size is the minimum between
904 * the desc_len and the remaining buffer length that
907 min = min_t(size_t, desc_len,
909 PAGE_SIZE - offset_in_page(buf)));
911 vm_page = vmalloc_to_page(buf);
913 vm_page = kmap_to_page(buf);
918 sg_set_page(sg, vm_page,
919 min, offset_in_page(buf));
921 min = min_t(size_t, len, desc_len);
923 sg_set_buf(sg, sg_buf, min);
931 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
944 void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
945 struct sg_table *sgt, enum dma_data_direction dir)
947 if (sgt->orig_nents) {
948 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
953 static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
955 struct device *tx_dev, *rx_dev;
956 struct spi_transfer *xfer;
963 tx_dev = ctlr->dma_tx->device->dev;
965 tx_dev = ctlr->dev.parent;
968 rx_dev = ctlr->dma_rx->device->dev;
970 rx_dev = ctlr->dev.parent;
972 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
973 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
976 if (xfer->tx_buf != NULL) {
977 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
978 (void *)xfer->tx_buf, xfer->len,
984 if (xfer->rx_buf != NULL) {
985 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
986 xfer->rx_buf, xfer->len,
989 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
996 ctlr->cur_msg_mapped = true;
1001 static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
1003 struct spi_transfer *xfer;
1004 struct device *tx_dev, *rx_dev;
1006 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
1010 tx_dev = ctlr->dma_tx->device->dev;
1012 tx_dev = ctlr->dev.parent;
1015 rx_dev = ctlr->dma_rx->device->dev;
1017 rx_dev = ctlr->dev.parent;
1019 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1020 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1023 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1024 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1027 ctlr->cur_msg_mapped = false;
1031 #else /* !CONFIG_HAS_DMA */
1032 static inline int __spi_map_msg(struct spi_controller *ctlr,
1033 struct spi_message *msg)
1038 static inline int __spi_unmap_msg(struct spi_controller *ctlr,
1039 struct spi_message *msg)
1043 #endif /* !CONFIG_HAS_DMA */
1045 static inline int spi_unmap_msg(struct spi_controller *ctlr,
1046 struct spi_message *msg)
1048 struct spi_transfer *xfer;
1050 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1052 * Restore the original value of tx_buf or rx_buf if they are
1055 if (xfer->tx_buf == ctlr->dummy_tx)
1056 xfer->tx_buf = NULL;
1057 if (xfer->rx_buf == ctlr->dummy_rx)
1058 xfer->rx_buf = NULL;
1061 return __spi_unmap_msg(ctlr, msg);
1064 static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1066 struct spi_transfer *xfer;
1068 unsigned int max_tx, max_rx;
1070 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1071 && !(msg->spi->mode & SPI_3WIRE)) {
1075 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1076 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1078 max_tx = max(xfer->len, max_tx);
1079 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1081 max_rx = max(xfer->len, max_rx);
1085 tmp = krealloc(ctlr->dummy_tx, max_tx,
1086 GFP_KERNEL | GFP_DMA);
1089 ctlr->dummy_tx = tmp;
1090 memset(tmp, 0, max_tx);
1094 tmp = krealloc(ctlr->dummy_rx, max_rx,
1095 GFP_KERNEL | GFP_DMA);
1098 ctlr->dummy_rx = tmp;
1101 if (max_tx || max_rx) {
1102 list_for_each_entry(xfer, &msg->transfers,
1107 xfer->tx_buf = ctlr->dummy_tx;
1109 xfer->rx_buf = ctlr->dummy_rx;
1114 return __spi_map_msg(ctlr, msg);
1117 static int spi_transfer_wait(struct spi_controller *ctlr,
1118 struct spi_message *msg,
1119 struct spi_transfer *xfer)
1121 struct spi_statistics *statm = &ctlr->statistics;
1122 struct spi_statistics *stats = &msg->spi->statistics;
1123 u32 speed_hz = xfer->speed_hz;
1124 unsigned long long ms;
1126 if (spi_controller_is_slave(ctlr)) {
1127 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1128 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1135 ms = 8LL * 1000LL * xfer->len;
1136 do_div(ms, speed_hz);
1137 ms += ms + 200; /* some tolerance */
1142 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1143 msecs_to_jiffies(ms));
1146 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1147 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1148 dev_err(&msg->spi->dev,
1149 "SPI transfer timed out\n");
1157 static void _spi_transfer_delay_ns(u32 ns)
1164 u32 us = DIV_ROUND_UP(ns, 1000);
1169 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1173 int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1175 u32 delay = _delay->value;
1176 u32 unit = _delay->unit;
1183 case SPI_DELAY_UNIT_USECS:
1186 case SPI_DELAY_UNIT_NSECS: /* nothing to do here */
1188 case SPI_DELAY_UNIT_SCK:
1189 /* clock cycles need to be obtained from spi_transfer */
1192 /* if there is no effective speed know, then approximate
1193 * by underestimating with half the requested hz
1195 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1198 delay *= DIV_ROUND_UP(1000000000, hz);
1206 EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1208 int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1217 delay = spi_delay_to_ns(_delay, xfer);
1221 _spi_transfer_delay_ns(delay);
1225 EXPORT_SYMBOL_GPL(spi_delay_exec);
1227 static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1228 struct spi_transfer *xfer)
1230 u32 delay = xfer->cs_change_delay.value;
1231 u32 unit = xfer->cs_change_delay.unit;
1234 /* return early on "fast" mode - for everything but USECS */
1236 if (unit == SPI_DELAY_UNIT_USECS)
1237 _spi_transfer_delay_ns(10000);
1241 ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1243 dev_err_once(&msg->spi->dev,
1244 "Use of unsupported delay unit %i, using default of 10us\n",
1246 _spi_transfer_delay_ns(10000);
1251 * spi_transfer_one_message - Default implementation of transfer_one_message()
1253 * This is a standard implementation of transfer_one_message() for
1254 * drivers which implement a transfer_one() operation. It provides
1255 * standard handling of delays and chip select management.
1257 static int spi_transfer_one_message(struct spi_controller *ctlr,
1258 struct spi_message *msg)
1260 struct spi_transfer *xfer;
1261 bool keep_cs = false;
1263 struct spi_statistics *statm = &ctlr->statistics;
1264 struct spi_statistics *stats = &msg->spi->statistics;
1266 spi_set_cs(msg->spi, true, false);
1268 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1269 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1271 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1272 trace_spi_transfer_start(msg, xfer);
1274 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1275 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1277 if (!ctlr->ptp_sts_supported) {
1278 xfer->ptp_sts_word_pre = 0;
1279 ptp_read_system_prets(xfer->ptp_sts);
1282 if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) {
1283 reinit_completion(&ctlr->xfer_completion);
1286 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1288 if (ctlr->cur_msg_mapped &&
1289 (xfer->error & SPI_TRANS_FAIL_NO_START)) {
1290 __spi_unmap_msg(ctlr, msg);
1291 ctlr->fallback = true;
1292 xfer->error &= ~SPI_TRANS_FAIL_NO_START;
1296 SPI_STATISTICS_INCREMENT_FIELD(statm,
1298 SPI_STATISTICS_INCREMENT_FIELD(stats,
1300 dev_err(&msg->spi->dev,
1301 "SPI transfer failed: %d\n", ret);
1306 ret = spi_transfer_wait(ctlr, msg, xfer);
1312 dev_err(&msg->spi->dev,
1313 "Bufferless transfer has length %u\n",
1317 if (!ctlr->ptp_sts_supported) {
1318 ptp_read_system_postts(xfer->ptp_sts);
1319 xfer->ptp_sts_word_post = xfer->len;
1322 trace_spi_transfer_stop(msg, xfer);
1324 if (msg->status != -EINPROGRESS)
1327 spi_transfer_delay_exec(xfer);
1329 if (xfer->cs_change) {
1330 if (list_is_last(&xfer->transfer_list,
1334 spi_set_cs(msg->spi, false, false);
1335 _spi_transfer_cs_change_delay(msg, xfer);
1336 spi_set_cs(msg->spi, true, false);
1340 msg->actual_length += xfer->len;
1344 if (ret != 0 || !keep_cs)
1345 spi_set_cs(msg->spi, false, false);
1347 if (msg->status == -EINPROGRESS)
1350 if (msg->status && ctlr->handle_err)
1351 ctlr->handle_err(ctlr, msg);
1353 spi_finalize_current_message(ctlr);
1359 * spi_finalize_current_transfer - report completion of a transfer
1360 * @ctlr: the controller reporting completion
1362 * Called by SPI drivers using the core transfer_one_message()
1363 * implementation to notify it that the current interrupt driven
1364 * transfer has finished and the next one may be scheduled.
1366 void spi_finalize_current_transfer(struct spi_controller *ctlr)
1368 complete(&ctlr->xfer_completion);
1370 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1372 static void spi_idle_runtime_pm(struct spi_controller *ctlr)
1374 if (ctlr->auto_runtime_pm) {
1375 pm_runtime_mark_last_busy(ctlr->dev.parent);
1376 pm_runtime_put_autosuspend(ctlr->dev.parent);
1381 * __spi_pump_messages - function which processes spi message queue
1382 * @ctlr: controller to process queue for
1383 * @in_kthread: true if we are in the context of the message pump thread
1385 * This function checks if there is any spi message in the queue that
1386 * needs processing and if so call out to the driver to initialize hardware
1387 * and transfer each message.
1389 * Note that it is called both from the kthread itself and also from
1390 * inside spi_sync(); the queue extraction handling at the top of the
1391 * function should deal with this safely.
1393 static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1395 struct spi_transfer *xfer;
1396 struct spi_message *msg;
1397 bool was_busy = false;
1398 unsigned long flags;
1402 spin_lock_irqsave(&ctlr->queue_lock, flags);
1404 /* Make sure we are not already running a message */
1405 if (ctlr->cur_msg) {
1406 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1410 /* If another context is idling the device then defer */
1412 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1413 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1417 /* Check if the queue is idle */
1418 if (list_empty(&ctlr->queue) || !ctlr->running) {
1420 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1424 /* Defer any non-atomic teardown to the thread */
1426 if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
1427 !ctlr->unprepare_transfer_hardware) {
1428 spi_idle_runtime_pm(ctlr);
1430 trace_spi_controller_idle(ctlr);
1432 kthread_queue_work(ctlr->kworker,
1433 &ctlr->pump_messages);
1435 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1440 ctlr->idling = true;
1441 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1443 kfree(ctlr->dummy_rx);
1444 ctlr->dummy_rx = NULL;
1445 kfree(ctlr->dummy_tx);
1446 ctlr->dummy_tx = NULL;
1447 if (ctlr->unprepare_transfer_hardware &&
1448 ctlr->unprepare_transfer_hardware(ctlr))
1450 "failed to unprepare transfer hardware\n");
1451 spi_idle_runtime_pm(ctlr);
1452 trace_spi_controller_idle(ctlr);
1454 spin_lock_irqsave(&ctlr->queue_lock, flags);
1455 ctlr->idling = false;
1456 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1460 /* Extract head of queue */
1461 msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1462 ctlr->cur_msg = msg;
1464 list_del_init(&msg->queue);
1469 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1471 mutex_lock(&ctlr->io_mutex);
1473 if (!was_busy && ctlr->auto_runtime_pm) {
1474 ret = pm_runtime_get_sync(ctlr->dev.parent);
1476 pm_runtime_put_noidle(ctlr->dev.parent);
1477 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1479 mutex_unlock(&ctlr->io_mutex);
1485 trace_spi_controller_busy(ctlr);
1487 if (!was_busy && ctlr->prepare_transfer_hardware) {
1488 ret = ctlr->prepare_transfer_hardware(ctlr);
1491 "failed to prepare transfer hardware: %d\n",
1494 if (ctlr->auto_runtime_pm)
1495 pm_runtime_put(ctlr->dev.parent);
1498 spi_finalize_current_message(ctlr);
1500 mutex_unlock(&ctlr->io_mutex);
1505 trace_spi_message_start(msg);
1507 if (ctlr->prepare_message) {
1508 ret = ctlr->prepare_message(ctlr, msg);
1510 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1513 spi_finalize_current_message(ctlr);
1516 ctlr->cur_msg_prepared = true;
1519 ret = spi_map_msg(ctlr, msg);
1522 spi_finalize_current_message(ctlr);
1526 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1527 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1528 xfer->ptp_sts_word_pre = 0;
1529 ptp_read_system_prets(xfer->ptp_sts);
1533 ret = ctlr->transfer_one_message(ctlr, msg);
1536 "failed to transfer one message from queue\n");
1541 mutex_unlock(&ctlr->io_mutex);
1543 /* Prod the scheduler in case transfer_one() was busy waiting */
1549 * spi_pump_messages - kthread work function which processes spi message queue
1550 * @work: pointer to kthread work struct contained in the controller struct
1552 static void spi_pump_messages(struct kthread_work *work)
1554 struct spi_controller *ctlr =
1555 container_of(work, struct spi_controller, pump_messages);
1557 __spi_pump_messages(ctlr, true);
1561 * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
1562 * TX timestamp for the requested byte from the SPI
1563 * transfer. The frequency with which this function
1564 * must be called (once per word, once for the whole
1565 * transfer, once per batch of words etc) is arbitrary
1566 * as long as the @tx buffer offset is greater than or
1567 * equal to the requested byte at the time of the
1568 * call. The timestamp is only taken once, at the
1569 * first such call. It is assumed that the driver
1570 * advances its @tx buffer pointer monotonically.
1571 * @ctlr: Pointer to the spi_controller structure of the driver
1572 * @xfer: Pointer to the transfer being timestamped
1573 * @progress: How many words (not bytes) have been transferred so far
1574 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1575 * transfer, for less jitter in time measurement. Only compatible
1576 * with PIO drivers. If true, must follow up with
1577 * spi_take_timestamp_post or otherwise system will crash.
1578 * WARNING: for fully predictable results, the CPU frequency must
1579 * also be under control (governor).
1581 void spi_take_timestamp_pre(struct spi_controller *ctlr,
1582 struct spi_transfer *xfer,
1583 size_t progress, bool irqs_off)
1588 if (xfer->timestamped)
1591 if (progress > xfer->ptp_sts_word_pre)
1594 /* Capture the resolution of the timestamp */
1595 xfer->ptp_sts_word_pre = progress;
1598 local_irq_save(ctlr->irq_flags);
1602 ptp_read_system_prets(xfer->ptp_sts);
1604 EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
1607 * spi_take_timestamp_post - helper for drivers to collect the end of the
1608 * TX timestamp for the requested byte from the SPI
1609 * transfer. Can be called with an arbitrary
1610 * frequency: only the first call where @tx exceeds
1611 * or is equal to the requested word will be
1613 * @ctlr: Pointer to the spi_controller structure of the driver
1614 * @xfer: Pointer to the transfer being timestamped
1615 * @progress: How many words (not bytes) have been transferred so far
1616 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1618 void spi_take_timestamp_post(struct spi_controller *ctlr,
1619 struct spi_transfer *xfer,
1620 size_t progress, bool irqs_off)
1625 if (xfer->timestamped)
1628 if (progress < xfer->ptp_sts_word_post)
1631 ptp_read_system_postts(xfer->ptp_sts);
1634 local_irq_restore(ctlr->irq_flags);
1638 /* Capture the resolution of the timestamp */
1639 xfer->ptp_sts_word_post = progress;
1641 xfer->timestamped = true;
1643 EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
1646 * spi_set_thread_rt - set the controller to pump at realtime priority
1647 * @ctlr: controller to boost priority of
1649 * This can be called because the controller requested realtime priority
1650 * (by setting the ->rt value before calling spi_register_controller()) or
1651 * because a device on the bus said that its transfers needed realtime
1654 * NOTE: at the moment if any device on a bus says it needs realtime then
1655 * the thread will be at realtime priority for all transfers on that
1656 * controller. If this eventually becomes a problem we may see if we can
1657 * find a way to boost the priority only temporarily during relevant
1660 static void spi_set_thread_rt(struct spi_controller *ctlr)
1662 dev_info(&ctlr->dev,
1663 "will run message pump with realtime priority\n");
1664 sched_set_fifo(ctlr->kworker->task);
1667 static int spi_init_queue(struct spi_controller *ctlr)
1669 ctlr->running = false;
1672 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
1673 if (IS_ERR(ctlr->kworker)) {
1674 dev_err(&ctlr->dev, "failed to create message pump kworker\n");
1675 return PTR_ERR(ctlr->kworker);
1678 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1681 * Controller config will indicate if this controller should run the
1682 * message pump with high (realtime) priority to reduce the transfer
1683 * latency on the bus by minimising the delay between a transfer
1684 * request and the scheduling of the message pump thread. Without this
1685 * setting the message pump thread will remain at default priority.
1688 spi_set_thread_rt(ctlr);
1694 * spi_get_next_queued_message() - called by driver to check for queued
1696 * @ctlr: the controller to check for queued messages
1698 * If there are more messages in the queue, the next message is returned from
1701 * Return: the next message in the queue, else NULL if the queue is empty.
1703 struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1705 struct spi_message *next;
1706 unsigned long flags;
1708 /* get a pointer to the next message, if any */
1709 spin_lock_irqsave(&ctlr->queue_lock, flags);
1710 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1712 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1716 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1719 * spi_finalize_current_message() - the current message is complete
1720 * @ctlr: the controller to return the message to
1722 * Called by the driver to notify the core that the message in the front of the
1723 * queue is complete and can be removed from the queue.
1725 void spi_finalize_current_message(struct spi_controller *ctlr)
1727 struct spi_transfer *xfer;
1728 struct spi_message *mesg;
1729 unsigned long flags;
1732 spin_lock_irqsave(&ctlr->queue_lock, flags);
1733 mesg = ctlr->cur_msg;
1734 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1736 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1737 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
1738 ptp_read_system_postts(xfer->ptp_sts);
1739 xfer->ptp_sts_word_post = xfer->len;
1743 if (unlikely(ctlr->ptp_sts_supported))
1744 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
1745 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
1747 spi_unmap_msg(ctlr, mesg);
1749 /* In the prepare_messages callback the spi bus has the opportunity to
1750 * split a transfer to smaller chunks.
1751 * Release splited transfers here since spi_map_msg is done on the
1752 * splited transfers.
1754 spi_res_release(ctlr, mesg);
1756 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1757 ret = ctlr->unprepare_message(ctlr, mesg);
1759 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1764 spin_lock_irqsave(&ctlr->queue_lock, flags);
1765 ctlr->cur_msg = NULL;
1766 ctlr->cur_msg_prepared = false;
1767 ctlr->fallback = false;
1768 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1769 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1771 trace_spi_message_done(mesg);
1775 mesg->complete(mesg->context);
1777 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1779 static int spi_start_queue(struct spi_controller *ctlr)
1781 unsigned long flags;
1783 spin_lock_irqsave(&ctlr->queue_lock, flags);
1785 if (ctlr->running || ctlr->busy) {
1786 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1790 ctlr->running = true;
1791 ctlr->cur_msg = NULL;
1792 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1794 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1799 static int spi_stop_queue(struct spi_controller *ctlr)
1801 unsigned long flags;
1802 unsigned limit = 500;
1805 spin_lock_irqsave(&ctlr->queue_lock, flags);
1808 * This is a bit lame, but is optimized for the common execution path.
1809 * A wait_queue on the ctlr->busy could be used, but then the common
1810 * execution path (pump_messages) would be required to call wake_up or
1811 * friends on every SPI message. Do this instead.
1813 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1814 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1815 usleep_range(10000, 11000);
1816 spin_lock_irqsave(&ctlr->queue_lock, flags);
1819 if (!list_empty(&ctlr->queue) || ctlr->busy)
1822 ctlr->running = false;
1824 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1827 dev_warn(&ctlr->dev, "could not stop message queue\n");
1833 static int spi_destroy_queue(struct spi_controller *ctlr)
1837 ret = spi_stop_queue(ctlr);
1840 * kthread_flush_worker will block until all work is done.
1841 * If the reason that stop_queue timed out is that the work will never
1842 * finish, then it does no good to call flush/stop thread, so
1846 dev_err(&ctlr->dev, "problem destroying queue\n");
1850 kthread_destroy_worker(ctlr->kworker);
1855 static int __spi_queued_transfer(struct spi_device *spi,
1856 struct spi_message *msg,
1859 struct spi_controller *ctlr = spi->controller;
1860 unsigned long flags;
1862 spin_lock_irqsave(&ctlr->queue_lock, flags);
1864 if (!ctlr->running) {
1865 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1868 msg->actual_length = 0;
1869 msg->status = -EINPROGRESS;
1871 list_add_tail(&msg->queue, &ctlr->queue);
1872 if (!ctlr->busy && need_pump)
1873 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1875 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1880 * spi_queued_transfer - transfer function for queued transfers
1881 * @spi: spi device which is requesting transfer
1882 * @msg: spi message which is to handled is queued to driver queue
1884 * Return: zero on success, else a negative error code.
1886 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1888 return __spi_queued_transfer(spi, msg, true);
1891 static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1895 ctlr->transfer = spi_queued_transfer;
1896 if (!ctlr->transfer_one_message)
1897 ctlr->transfer_one_message = spi_transfer_one_message;
1899 /* Initialize and start queue */
1900 ret = spi_init_queue(ctlr);
1902 dev_err(&ctlr->dev, "problem initializing queue\n");
1903 goto err_init_queue;
1905 ctlr->queued = true;
1906 ret = spi_start_queue(ctlr);
1908 dev_err(&ctlr->dev, "problem starting queue\n");
1909 goto err_start_queue;
1915 spi_destroy_queue(ctlr);
1921 * spi_flush_queue - Send all pending messages in the queue from the callers'
1923 * @ctlr: controller to process queue for
1925 * This should be used when one wants to ensure all pending messages have been
1926 * sent before doing something. Is used by the spi-mem code to make sure SPI
1927 * memory operations do not preempt regular SPI transfers that have been queued
1928 * before the spi-mem operation.
1930 void spi_flush_queue(struct spi_controller *ctlr)
1932 if (ctlr->transfer == spi_queued_transfer)
1933 __spi_pump_messages(ctlr, false);
1936 /*-------------------------------------------------------------------------*/
1938 #if defined(CONFIG_OF)
1939 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1940 struct device_node *nc)
1945 /* Mode (clock phase/polarity/etc.) */
1946 if (of_property_read_bool(nc, "spi-cpha"))
1947 spi->mode |= SPI_CPHA;
1948 if (of_property_read_bool(nc, "spi-cpol"))
1949 spi->mode |= SPI_CPOL;
1950 if (of_property_read_bool(nc, "spi-3wire"))
1951 spi->mode |= SPI_3WIRE;
1952 if (of_property_read_bool(nc, "spi-lsb-first"))
1953 spi->mode |= SPI_LSB_FIRST;
1954 if (of_property_read_bool(nc, "spi-cs-high"))
1955 spi->mode |= SPI_CS_HIGH;
1957 /* Device DUAL/QUAD mode */
1958 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1961 spi->mode |= SPI_NO_TX;
1966 spi->mode |= SPI_TX_DUAL;
1969 spi->mode |= SPI_TX_QUAD;
1972 spi->mode |= SPI_TX_OCTAL;
1975 dev_warn(&ctlr->dev,
1976 "spi-tx-bus-width %d not supported\n",
1982 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1985 spi->mode |= SPI_NO_RX;
1990 spi->mode |= SPI_RX_DUAL;
1993 spi->mode |= SPI_RX_QUAD;
1996 spi->mode |= SPI_RX_OCTAL;
1999 dev_warn(&ctlr->dev,
2000 "spi-rx-bus-width %d not supported\n",
2006 if (spi_controller_is_slave(ctlr)) {
2007 if (!of_node_name_eq(nc, "slave")) {
2008 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
2015 /* Device address */
2016 rc = of_property_read_u32(nc, "reg", &value);
2018 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
2022 spi->chip_select = value;
2025 if (!of_property_read_u32(nc, "spi-max-frequency", &value))
2026 spi->max_speed_hz = value;
2031 static struct spi_device *
2032 of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
2034 struct spi_device *spi;
2037 /* Alloc an spi_device */
2038 spi = spi_alloc_device(ctlr);
2040 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
2045 /* Select device driver */
2046 rc = of_modalias_node(nc, spi->modalias,
2047 sizeof(spi->modalias));
2049 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
2053 rc = of_spi_parse_dt(ctlr, spi, nc);
2057 /* Store a pointer to the node in the device structure */
2059 spi->dev.of_node = nc;
2061 /* Register the new device */
2062 rc = spi_add_device(spi);
2064 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
2065 goto err_of_node_put;
2078 * of_register_spi_devices() - Register child devices onto the SPI bus
2079 * @ctlr: Pointer to spi_controller device
2081 * Registers an spi_device for each child node of controller node which
2082 * represents a valid SPI slave.
2084 static void of_register_spi_devices(struct spi_controller *ctlr)
2086 struct spi_device *spi;
2087 struct device_node *nc;
2089 if (!ctlr->dev.of_node)
2092 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2093 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2095 spi = of_register_spi_device(ctlr, nc);
2097 dev_warn(&ctlr->dev,
2098 "Failed to create SPI device for %pOF\n", nc);
2099 of_node_clear_flag(nc, OF_POPULATED);
2104 static void of_register_spi_devices(struct spi_controller *ctlr) { }
2108 struct acpi_spi_lookup {
2109 struct spi_controller *ctlr;
2117 static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2118 struct acpi_spi_lookup *lookup)
2120 const union acpi_object *obj;
2122 if (!x86_apple_machine)
2125 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2126 && obj->buffer.length >= 4)
2127 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2129 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2130 && obj->buffer.length == 8)
2131 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2133 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2134 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2135 lookup->mode |= SPI_LSB_FIRST;
2137 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2138 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2139 lookup->mode |= SPI_CPOL;
2141 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2142 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2143 lookup->mode |= SPI_CPHA;
2146 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2148 struct acpi_spi_lookup *lookup = data;
2149 struct spi_controller *ctlr = lookup->ctlr;
2151 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2152 struct acpi_resource_spi_serialbus *sb;
2153 acpi_handle parent_handle;
2156 sb = &ares->data.spi_serial_bus;
2157 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2159 status = acpi_get_handle(NULL,
2160 sb->resource_source.string_ptr,
2163 if (ACPI_FAILURE(status) ||
2164 ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
2168 * ACPI DeviceSelection numbering is handled by the
2169 * host controller driver in Windows and can vary
2170 * from driver to driver. In Linux we always expect
2171 * 0 .. max - 1 so we need to ask the driver to
2172 * translate between the two schemes.
2174 if (ctlr->fw_translate_cs) {
2175 int cs = ctlr->fw_translate_cs(ctlr,
2176 sb->device_selection);
2179 lookup->chip_select = cs;
2181 lookup->chip_select = sb->device_selection;
2184 lookup->max_speed_hz = sb->connection_speed;
2185 lookup->bits_per_word = sb->data_bit_length;
2187 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2188 lookup->mode |= SPI_CPHA;
2189 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2190 lookup->mode |= SPI_CPOL;
2191 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2192 lookup->mode |= SPI_CS_HIGH;
2194 } else if (lookup->irq < 0) {
2197 if (acpi_dev_resource_interrupt(ares, 0, &r))
2198 lookup->irq = r.start;
2201 /* Always tell the ACPI core to skip this resource */
2205 static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2206 struct acpi_device *adev)
2208 acpi_handle parent_handle = NULL;
2209 struct list_head resource_list;
2210 struct acpi_spi_lookup lookup = {};
2211 struct spi_device *spi;
2214 if (acpi_bus_get_status(adev) || !adev->status.present ||
2215 acpi_device_enumerated(adev))
2221 INIT_LIST_HEAD(&resource_list);
2222 ret = acpi_dev_get_resources(adev, &resource_list,
2223 acpi_spi_add_resource, &lookup);
2224 acpi_dev_free_resource_list(&resource_list);
2227 /* found SPI in _CRS but it points to another controller */
2230 if (!lookup.max_speed_hz &&
2231 ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
2232 ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {
2233 /* Apple does not use _CRS but nested devices for SPI slaves */
2234 acpi_spi_parse_apple_properties(adev, &lookup);
2237 if (!lookup.max_speed_hz)
2240 spi = spi_alloc_device(ctlr);
2242 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
2243 dev_name(&adev->dev));
2244 return AE_NO_MEMORY;
2248 ACPI_COMPANION_SET(&spi->dev, adev);
2249 spi->max_speed_hz = lookup.max_speed_hz;
2250 spi->mode |= lookup.mode;
2251 spi->irq = lookup.irq;
2252 spi->bits_per_word = lookup.bits_per_word;
2253 spi->chip_select = lookup.chip_select;
2255 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2256 sizeof(spi->modalias));
2259 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
2261 acpi_device_set_enumerated(adev);
2263 adev->power.flags.ignore_parent = true;
2264 if (spi_add_device(spi)) {
2265 adev->power.flags.ignore_parent = false;
2266 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2267 dev_name(&adev->dev));
2274 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2275 void *data, void **return_value)
2277 struct spi_controller *ctlr = data;
2278 struct acpi_device *adev;
2280 if (acpi_bus_get_device(handle, &adev))
2283 return acpi_register_spi_device(ctlr, adev);
2286 #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2288 static void acpi_register_spi_devices(struct spi_controller *ctlr)
2293 handle = ACPI_HANDLE(ctlr->dev.parent);
2297 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2298 SPI_ACPI_ENUMERATE_MAX_DEPTH,
2299 acpi_spi_add_device, NULL, ctlr, NULL);
2300 if (ACPI_FAILURE(status))
2301 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2304 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2305 #endif /* CONFIG_ACPI */
2307 static void spi_controller_release(struct device *dev)
2309 struct spi_controller *ctlr;
2311 ctlr = container_of(dev, struct spi_controller, dev);
2315 static struct class spi_master_class = {
2316 .name = "spi_master",
2317 .owner = THIS_MODULE,
2318 .dev_release = spi_controller_release,
2319 .dev_groups = spi_master_groups,
2322 #ifdef CONFIG_SPI_SLAVE
2324 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2326 * @spi: device used for the current transfer
2328 int spi_slave_abort(struct spi_device *spi)
2330 struct spi_controller *ctlr = spi->controller;
2332 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
2333 return ctlr->slave_abort(ctlr);
2337 EXPORT_SYMBOL_GPL(spi_slave_abort);
2339 static int match_true(struct device *dev, void *data)
2344 static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2347 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2349 struct device *child;
2351 child = device_find_child(&ctlr->dev, NULL, match_true);
2352 return sprintf(buf, "%s\n",
2353 child ? to_spi_device(child)->modalias : NULL);
2356 static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
2357 const char *buf, size_t count)
2359 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2361 struct spi_device *spi;
2362 struct device *child;
2366 rc = sscanf(buf, "%31s", name);
2367 if (rc != 1 || !name[0])
2370 child = device_find_child(&ctlr->dev, NULL, match_true);
2372 /* Remove registered slave */
2373 device_unregister(child);
2377 if (strcmp(name, "(null)")) {
2378 /* Register new slave */
2379 spi = spi_alloc_device(ctlr);
2383 strlcpy(spi->modalias, name, sizeof(spi->modalias));
2385 rc = spi_add_device(spi);
2395 static DEVICE_ATTR_RW(slave);
2397 static struct attribute *spi_slave_attrs[] = {
2398 &dev_attr_slave.attr,
2402 static const struct attribute_group spi_slave_group = {
2403 .attrs = spi_slave_attrs,
2406 static const struct attribute_group *spi_slave_groups[] = {
2407 &spi_controller_statistics_group,
2412 static struct class spi_slave_class = {
2413 .name = "spi_slave",
2414 .owner = THIS_MODULE,
2415 .dev_release = spi_controller_release,
2416 .dev_groups = spi_slave_groups,
2419 extern struct class spi_slave_class; /* dummy */
2423 * __spi_alloc_controller - allocate an SPI master or slave controller
2424 * @dev: the controller, possibly using the platform_bus
2425 * @size: how much zeroed driver-private data to allocate; the pointer to this
2426 * memory is in the driver_data field of the returned device, accessible
2427 * with spi_controller_get_devdata(); the memory is cacheline aligned;
2428 * drivers granting DMA access to portions of their private data need to
2429 * round up @size using ALIGN(size, dma_get_cache_alignment()).
2430 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2431 * slave (true) controller
2432 * Context: can sleep
2434 * This call is used only by SPI controller drivers, which are the
2435 * only ones directly touching chip registers. It's how they allocate
2436 * an spi_controller structure, prior to calling spi_register_controller().
2438 * This must be called from context that can sleep.
2440 * The caller is responsible for assigning the bus number and initializing the
2441 * controller's methods before calling spi_register_controller(); and (after
2442 * errors adding the device) calling spi_controller_put() to prevent a memory
2445 * Return: the SPI controller structure on success, else NULL.
2447 struct spi_controller *__spi_alloc_controller(struct device *dev,
2448 unsigned int size, bool slave)
2450 struct spi_controller *ctlr;
2451 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
2456 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
2460 device_initialize(&ctlr->dev);
2462 ctlr->num_chipselect = 1;
2463 ctlr->slave = slave;
2464 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2465 ctlr->dev.class = &spi_slave_class;
2467 ctlr->dev.class = &spi_master_class;
2468 ctlr->dev.parent = dev;
2469 pm_suspend_ignore_children(&ctlr->dev, true);
2470 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
2474 EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2476 static void devm_spi_release_controller(struct device *dev, void *ctlr)
2478 spi_controller_put(*(struct spi_controller **)ctlr);
2482 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
2483 * @dev: physical device of SPI controller
2484 * @size: how much zeroed driver-private data to allocate
2485 * @slave: whether to allocate an SPI master (false) or SPI slave (true)
2486 * Context: can sleep
2488 * Allocate an SPI controller and automatically release a reference on it
2489 * when @dev is unbound from its driver. Drivers are thus relieved from
2490 * having to call spi_controller_put().
2492 * The arguments to this function are identical to __spi_alloc_controller().
2494 * Return: the SPI controller structure on success, else NULL.
2496 struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
2500 struct spi_controller **ptr, *ctlr;
2502 ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),
2507 ctlr = __spi_alloc_controller(dev, size, slave);
2509 ctlr->devm_allocated = true;
2511 devres_add(dev, ptr);
2518 EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);
2521 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2524 struct device_node *np = ctlr->dev.of_node;
2529 nb = of_gpio_named_count(np, "cs-gpios");
2530 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2532 /* Return error only for an incorrectly formed cs-gpios property */
2533 if (nb == 0 || nb == -ENOENT)
2538 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2540 ctlr->cs_gpios = cs;
2542 if (!ctlr->cs_gpios)
2545 for (i = 0; i < ctlr->num_chipselect; i++)
2548 for (i = 0; i < nb; i++)
2549 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2554 static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2561 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2562 * @ctlr: The SPI master to grab GPIO descriptors for
2564 static int spi_get_gpio_descs(struct spi_controller *ctlr)
2567 struct gpio_desc **cs;
2568 struct device *dev = &ctlr->dev;
2569 unsigned long native_cs_mask = 0;
2570 unsigned int num_cs_gpios = 0;
2572 nb = gpiod_count(dev, "cs");
2574 /* No GPIOs at all is fine, else return the error */
2580 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2582 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
2586 ctlr->cs_gpiods = cs;
2588 for (i = 0; i < nb; i++) {
2590 * Most chipselects are active low, the inverted
2591 * semantics are handled by special quirks in gpiolib,
2592 * so initializing them GPIOD_OUT_LOW here means
2593 * "unasserted", in most cases this will drive the physical
2596 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
2599 return PTR_ERR(cs[i]);
2603 * If we find a CS GPIO, name it after the device and
2608 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
2612 gpiod_set_consumer_name(cs[i], gpioname);
2617 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
2618 dev_err(dev, "Invalid native chip select %d\n", i);
2621 native_cs_mask |= BIT(i);
2624 ctlr->unused_native_cs = ffz(native_cs_mask);
2625 if (num_cs_gpios && ctlr->max_native_cs &&
2626 ctlr->unused_native_cs >= ctlr->max_native_cs) {
2627 dev_err(dev, "No unused native chip select available\n");
2634 static int spi_controller_check_ops(struct spi_controller *ctlr)
2637 * The controller may implement only the high-level SPI-memory like
2638 * operations if it does not support regular SPI transfers, and this is
2640 * If ->mem_ops is NULL, we request that at least one of the
2641 * ->transfer_xxx() method be implemented.
2643 if (ctlr->mem_ops) {
2644 if (!ctlr->mem_ops->exec_op)
2646 } else if (!ctlr->transfer && !ctlr->transfer_one &&
2647 !ctlr->transfer_one_message) {
2655 * spi_register_controller - register SPI master or slave controller
2656 * @ctlr: initialized master, originally from spi_alloc_master() or
2658 * Context: can sleep
2660 * SPI controllers connect to their drivers using some non-SPI bus,
2661 * such as the platform bus. The final stage of probe() in that code
2662 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2664 * SPI controllers use board specific (often SOC specific) bus numbers,
2665 * and board-specific addressing for SPI devices combines those numbers
2666 * with chip select numbers. Since SPI does not directly support dynamic
2667 * device identification, boards need configuration tables telling which
2668 * chip is at which address.
2670 * This must be called from context that can sleep. It returns zero on
2671 * success, else a negative error code (dropping the controller's refcount).
2672 * After a successful return, the caller is responsible for calling
2673 * spi_unregister_controller().
2675 * Return: zero on success, else a negative error code.
2677 int spi_register_controller(struct spi_controller *ctlr)
2679 struct device *dev = ctlr->dev.parent;
2680 struct boardinfo *bi;
2682 int id, first_dynamic;
2688 * Make sure all necessary hooks are implemented before registering
2689 * the SPI controller.
2691 status = spi_controller_check_ops(ctlr);
2695 if (ctlr->bus_num >= 0) {
2696 /* devices with a fixed bus num must check-in with the num */
2697 mutex_lock(&board_lock);
2698 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2699 ctlr->bus_num + 1, GFP_KERNEL);
2700 mutex_unlock(&board_lock);
2701 if (WARN(id < 0, "couldn't get idr"))
2702 return id == -ENOSPC ? -EBUSY : id;
2704 } else if (ctlr->dev.of_node) {
2705 /* allocate dynamic bus number using Linux idr */
2706 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2709 mutex_lock(&board_lock);
2710 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2711 ctlr->bus_num + 1, GFP_KERNEL);
2712 mutex_unlock(&board_lock);
2713 if (WARN(id < 0, "couldn't get idr"))
2714 return id == -ENOSPC ? -EBUSY : id;
2717 if (ctlr->bus_num < 0) {
2718 first_dynamic = of_alias_get_highest_id("spi");
2719 if (first_dynamic < 0)
2724 mutex_lock(&board_lock);
2725 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2727 mutex_unlock(&board_lock);
2728 if (WARN(id < 0, "couldn't get idr"))
2732 INIT_LIST_HEAD(&ctlr->queue);
2733 spin_lock_init(&ctlr->queue_lock);
2734 spin_lock_init(&ctlr->bus_lock_spinlock);
2735 mutex_init(&ctlr->bus_lock_mutex);
2736 mutex_init(&ctlr->io_mutex);
2737 ctlr->bus_lock_flag = 0;
2738 init_completion(&ctlr->xfer_completion);
2739 if (!ctlr->max_dma_len)
2740 ctlr->max_dma_len = INT_MAX;
2742 /* register the device, then userspace will see it.
2743 * registration fails if the bus ID is in use.
2745 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2747 if (!spi_controller_is_slave(ctlr)) {
2748 if (ctlr->use_gpio_descriptors) {
2749 status = spi_get_gpio_descs(ctlr);
2753 * A controller using GPIO descriptors always
2754 * supports SPI_CS_HIGH if need be.
2756 ctlr->mode_bits |= SPI_CS_HIGH;
2758 /* Legacy code path for GPIOs from DT */
2759 status = of_spi_get_gpio_numbers(ctlr);
2766 * Even if it's just one always-selected device, there must
2767 * be at least one chipselect.
2769 if (!ctlr->num_chipselect) {
2774 status = device_add(&ctlr->dev);
2777 dev_dbg(dev, "registered %s %s\n",
2778 spi_controller_is_slave(ctlr) ? "slave" : "master",
2779 dev_name(&ctlr->dev));
2782 * If we're using a queued driver, start the queue. Note that we don't
2783 * need the queueing logic if the driver is only supporting high-level
2784 * memory operations.
2786 if (ctlr->transfer) {
2787 dev_info(dev, "controller is unqueued, this is deprecated\n");
2788 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2789 status = spi_controller_initialize_queue(ctlr);
2791 device_del(&ctlr->dev);
2795 /* add statistics */
2796 spin_lock_init(&ctlr->statistics.lock);
2798 mutex_lock(&board_lock);
2799 list_add_tail(&ctlr->list, &spi_controller_list);
2800 list_for_each_entry(bi, &board_list, list)
2801 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2802 mutex_unlock(&board_lock);
2804 /* Register devices from the device tree and ACPI */
2805 of_register_spi_devices(ctlr);
2806 acpi_register_spi_devices(ctlr);
2810 mutex_lock(&board_lock);
2811 idr_remove(&spi_master_idr, ctlr->bus_num);
2812 mutex_unlock(&board_lock);
2815 EXPORT_SYMBOL_GPL(spi_register_controller);
2817 static void devm_spi_unregister(void *ctlr)
2819 spi_unregister_controller(ctlr);
2823 * devm_spi_register_controller - register managed SPI master or slave
2825 * @dev: device managing SPI controller
2826 * @ctlr: initialized controller, originally from spi_alloc_master() or
2828 * Context: can sleep
2830 * Register a SPI device as with spi_register_controller() which will
2831 * automatically be unregistered and freed.
2833 * Return: zero on success, else a negative error code.
2835 int devm_spi_register_controller(struct device *dev,
2836 struct spi_controller *ctlr)
2840 ret = spi_register_controller(ctlr);
2844 return devm_add_action_or_reset(dev, devm_spi_unregister, ctlr);
2846 EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2848 static int __unregister(struct device *dev, void *null)
2850 spi_unregister_device(to_spi_device(dev));
2855 * spi_unregister_controller - unregister SPI master or slave controller
2856 * @ctlr: the controller being unregistered
2857 * Context: can sleep
2859 * This call is used only by SPI controller drivers, which are the
2860 * only ones directly touching chip registers.
2862 * This must be called from context that can sleep.
2864 * Note that this function also drops a reference to the controller.
2866 void spi_unregister_controller(struct spi_controller *ctlr)
2868 struct spi_controller *found;
2869 int id = ctlr->bus_num;
2871 /* Prevent addition of new devices, unregister existing ones */
2872 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2873 mutex_lock(&spi_add_lock);
2875 device_for_each_child(&ctlr->dev, NULL, __unregister);
2877 /* First make sure that this controller was ever added */
2878 mutex_lock(&board_lock);
2879 found = idr_find(&spi_master_idr, id);
2880 mutex_unlock(&board_lock);
2882 if (spi_destroy_queue(ctlr))
2883 dev_err(&ctlr->dev, "queue remove failed\n");
2885 mutex_lock(&board_lock);
2886 list_del(&ctlr->list);
2887 mutex_unlock(&board_lock);
2889 device_del(&ctlr->dev);
2891 /* Release the last reference on the controller if its driver
2892 * has not yet been converted to devm_spi_alloc_master/slave().
2894 if (!ctlr->devm_allocated)
2895 put_device(&ctlr->dev);
2898 mutex_lock(&board_lock);
2900 idr_remove(&spi_master_idr, id);
2901 mutex_unlock(&board_lock);
2903 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2904 mutex_unlock(&spi_add_lock);
2906 EXPORT_SYMBOL_GPL(spi_unregister_controller);
2908 int spi_controller_suspend(struct spi_controller *ctlr)
2912 /* Basically no-ops for non-queued controllers */
2916 ret = spi_stop_queue(ctlr);
2918 dev_err(&ctlr->dev, "queue stop failed\n");
2922 EXPORT_SYMBOL_GPL(spi_controller_suspend);
2924 int spi_controller_resume(struct spi_controller *ctlr)
2931 ret = spi_start_queue(ctlr);
2933 dev_err(&ctlr->dev, "queue restart failed\n");
2937 EXPORT_SYMBOL_GPL(spi_controller_resume);
2939 static int __spi_controller_match(struct device *dev, const void *data)
2941 struct spi_controller *ctlr;
2942 const u16 *bus_num = data;
2944 ctlr = container_of(dev, struct spi_controller, dev);
2945 return ctlr->bus_num == *bus_num;
2949 * spi_busnum_to_master - look up master associated with bus_num
2950 * @bus_num: the master's bus number
2951 * Context: can sleep
2953 * This call may be used with devices that are registered after
2954 * arch init time. It returns a refcounted pointer to the relevant
2955 * spi_controller (which the caller must release), or NULL if there is
2956 * no such master registered.
2958 * Return: the SPI master structure on success, else NULL.
2960 struct spi_controller *spi_busnum_to_master(u16 bus_num)
2963 struct spi_controller *ctlr = NULL;
2965 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2966 __spi_controller_match);
2968 ctlr = container_of(dev, struct spi_controller, dev);
2969 /* reference got in class_find_device */
2972 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2974 /*-------------------------------------------------------------------------*/
2976 /* Core methods for SPI resource management */
2979 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2980 * during the processing of a spi_message while using
2982 * @spi: the spi device for which we allocate memory
2983 * @release: the release code to execute for this resource
2984 * @size: size to alloc and return
2985 * @gfp: GFP allocation flags
2987 * Return: the pointer to the allocated data
2989 * This may get enhanced in the future to allocate from a memory pool
2990 * of the @spi_device or @spi_controller to avoid repeated allocations.
2992 void *spi_res_alloc(struct spi_device *spi,
2993 spi_res_release_t release,
2994 size_t size, gfp_t gfp)
2996 struct spi_res *sres;
2998 sres = kzalloc(sizeof(*sres) + size, gfp);
3002 INIT_LIST_HEAD(&sres->entry);
3003 sres->release = release;
3007 EXPORT_SYMBOL_GPL(spi_res_alloc);
3010 * spi_res_free - free an spi resource
3011 * @res: pointer to the custom data of a resource
3014 void spi_res_free(void *res)
3016 struct spi_res *sres = container_of(res, struct spi_res, data);
3021 WARN_ON(!list_empty(&sres->entry));
3024 EXPORT_SYMBOL_GPL(spi_res_free);
3027 * spi_res_add - add a spi_res to the spi_message
3028 * @message: the spi message
3029 * @res: the spi_resource
3031 void spi_res_add(struct spi_message *message, void *res)
3033 struct spi_res *sres = container_of(res, struct spi_res, data);
3035 WARN_ON(!list_empty(&sres->entry));
3036 list_add_tail(&sres->entry, &message->resources);
3038 EXPORT_SYMBOL_GPL(spi_res_add);
3041 * spi_res_release - release all spi resources for this message
3042 * @ctlr: the @spi_controller
3043 * @message: the @spi_message
3045 void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
3047 struct spi_res *res, *tmp;
3049 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
3051 res->release(ctlr, message, res->data);
3053 list_del(&res->entry);
3058 EXPORT_SYMBOL_GPL(spi_res_release);
3060 /*-------------------------------------------------------------------------*/
3062 /* Core methods for spi_message alterations */
3064 static void __spi_replace_transfers_release(struct spi_controller *ctlr,
3065 struct spi_message *msg,
3068 struct spi_replaced_transfers *rxfer = res;
3071 /* call extra callback if requested */
3073 rxfer->release(ctlr, msg, res);
3075 /* insert replaced transfers back into the message */
3076 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
3078 /* remove the formerly inserted entries */
3079 for (i = 0; i < rxfer->inserted; i++)
3080 list_del(&rxfer->inserted_transfers[i].transfer_list);
3084 * spi_replace_transfers - replace transfers with several transfers
3085 * and register change with spi_message.resources
3086 * @msg: the spi_message we work upon
3087 * @xfer_first: the first spi_transfer we want to replace
3088 * @remove: number of transfers to remove
3089 * @insert: the number of transfers we want to insert instead
3090 * @release: extra release code necessary in some circumstances
3091 * @extradatasize: extra data to allocate (with alignment guarantees
3092 * of struct @spi_transfer)
3095 * Returns: pointer to @spi_replaced_transfers,
3096 * PTR_ERR(...) in case of errors.
3098 struct spi_replaced_transfers *spi_replace_transfers(
3099 struct spi_message *msg,
3100 struct spi_transfer *xfer_first,
3103 spi_replaced_release_t release,
3104 size_t extradatasize,
3107 struct spi_replaced_transfers *rxfer;
3108 struct spi_transfer *xfer;
3111 /* allocate the structure using spi_res */
3112 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
3113 struct_size(rxfer, inserted_transfers, insert)
3117 return ERR_PTR(-ENOMEM);
3119 /* the release code to invoke before running the generic release */
3120 rxfer->release = release;
3122 /* assign extradata */
3125 &rxfer->inserted_transfers[insert];
3127 /* init the replaced_transfers list */
3128 INIT_LIST_HEAD(&rxfer->replaced_transfers);
3130 /* assign the list_entry after which we should reinsert
3131 * the @replaced_transfers - it may be spi_message.messages!
3133 rxfer->replaced_after = xfer_first->transfer_list.prev;
3135 /* remove the requested number of transfers */
3136 for (i = 0; i < remove; i++) {
3137 /* if the entry after replaced_after it is msg->transfers
3138 * then we have been requested to remove more transfers
3139 * than are in the list
3141 if (rxfer->replaced_after->next == &msg->transfers) {
3142 dev_err(&msg->spi->dev,
3143 "requested to remove more spi_transfers than are available\n");
3144 /* insert replaced transfers back into the message */
3145 list_splice(&rxfer->replaced_transfers,
3146 rxfer->replaced_after);
3148 /* free the spi_replace_transfer structure */
3149 spi_res_free(rxfer);
3151 /* and return with an error */
3152 return ERR_PTR(-EINVAL);
3155 /* remove the entry after replaced_after from list of
3156 * transfers and add it to list of replaced_transfers
3158 list_move_tail(rxfer->replaced_after->next,
3159 &rxfer->replaced_transfers);
3162 /* create copy of the given xfer with identical settings
3163 * based on the first transfer to get removed
3165 for (i = 0; i < insert; i++) {
3166 /* we need to run in reverse order */
3167 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3169 /* copy all spi_transfer data */
3170 memcpy(xfer, xfer_first, sizeof(*xfer));
3173 list_add(&xfer->transfer_list, rxfer->replaced_after);
3175 /* clear cs_change and delay for all but the last */
3177 xfer->cs_change = false;
3178 xfer->delay.value = 0;
3182 /* set up inserted */
3183 rxfer->inserted = insert;
3185 /* and register it with spi_res/spi_message */
3186 spi_res_add(msg, rxfer);
3190 EXPORT_SYMBOL_GPL(spi_replace_transfers);
3192 static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3193 struct spi_message *msg,
3194 struct spi_transfer **xferp,
3198 struct spi_transfer *xfer = *xferp, *xfers;
3199 struct spi_replaced_transfers *srt;
3203 /* calculate how many we have to replace */
3204 count = DIV_ROUND_UP(xfer->len, maxsize);
3206 /* create replacement */
3207 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
3209 return PTR_ERR(srt);
3210 xfers = srt->inserted_transfers;
3212 /* now handle each of those newly inserted spi_transfers
3213 * note that the replacements spi_transfers all are preset
3214 * to the same values as *xferp, so tx_buf, rx_buf and len
3215 * are all identical (as well as most others)
3216 * so we just have to fix up len and the pointers.
3218 * this also includes support for the depreciated
3219 * spi_message.is_dma_mapped interface
3222 /* the first transfer just needs the length modified, so we
3223 * run it outside the loop
3225 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3227 /* all the others need rx_buf/tx_buf also set */
3228 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3229 /* update rx_buf, tx_buf and dma */
3230 if (xfers[i].rx_buf)
3231 xfers[i].rx_buf += offset;
3232 if (xfers[i].rx_dma)
3233 xfers[i].rx_dma += offset;
3234 if (xfers[i].tx_buf)
3235 xfers[i].tx_buf += offset;
3236 if (xfers[i].tx_dma)
3237 xfers[i].tx_dma += offset;
3240 xfers[i].len = min(maxsize, xfers[i].len - offset);
3243 /* we set up xferp to the last entry we have inserted,
3244 * so that we skip those already split transfers
3246 *xferp = &xfers[count - 1];
3248 /* increment statistics counters */
3249 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3250 transfers_split_maxsize);
3251 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
3252 transfers_split_maxsize);
3258 * spi_split_transfers_maxsize - split spi transfers into multiple transfers
3259 * when an individual transfer exceeds a
3261 * @ctlr: the @spi_controller for this transfer
3262 * @msg: the @spi_message to transform
3263 * @maxsize: the maximum when to apply this
3264 * @gfp: GFP allocation flags
3266 * Return: status of transformation
3268 int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3269 struct spi_message *msg,
3273 struct spi_transfer *xfer;
3276 /* iterate over the transfer_list,
3277 * but note that xfer is advanced to the last transfer inserted
3278 * to avoid checking sizes again unnecessarily (also xfer does
3279 * potentiall belong to a different list by the time the
3280 * replacement has happened
3282 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3283 if (xfer->len > maxsize) {
3284 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3293 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3295 /*-------------------------------------------------------------------------*/
3297 /* Core methods for SPI controller protocol drivers. Some of the
3298 * other core methods are currently defined as inline functions.
3301 static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3304 if (ctlr->bits_per_word_mask) {
3305 /* Only 32 bits fit in the mask */
3306 if (bits_per_word > 32)
3308 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3316 * spi_setup - setup SPI mode and clock rate
3317 * @spi: the device whose settings are being modified
3318 * Context: can sleep, and no requests are queued to the device
3320 * SPI protocol drivers may need to update the transfer mode if the
3321 * device doesn't work with its default. They may likewise need
3322 * to update clock rates or word sizes from initial values. This function
3323 * changes those settings, and must be called from a context that can sleep.
3324 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3325 * effect the next time the device is selected and data is transferred to
3326 * or from it. When this function returns, the spi device is deselected.
3328 * Note that this call will fail if the protocol driver specifies an option
3329 * that the underlying controller or its driver does not support. For
3330 * example, not all hardware supports wire transfers using nine bit words,
3331 * LSB-first wire encoding, or active-high chipselects.
3333 * Return: zero on success, else a negative error code.
3335 int spi_setup(struct spi_device *spi)
3337 unsigned bad_bits, ugly_bits;
3341 * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
3342 * are set at the same time
3344 if ((hweight_long(spi->mode &
3345 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
3346 (hweight_long(spi->mode &
3347 (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
3349 "setup: can not select any two of dual, quad and no-rx/tx at the same time\n");
3352 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
3354 if ((spi->mode & SPI_3WIRE) && (spi->mode &
3355 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3356 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3358 /* help drivers fail *cleanly* when they need options
3359 * that aren't supported with their current controller
3360 * SPI_CS_WORD has a fallback software implementation,
3361 * so it is ignored here.
3363 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
3364 SPI_NO_TX | SPI_NO_RX);
3365 /* nothing prevents from working with active-high CS in case if it
3366 * is driven by GPIO.
3368 if (gpio_is_valid(spi->cs_gpio))
3369 bad_bits &= ~SPI_CS_HIGH;
3370 ugly_bits = bad_bits &
3371 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3372 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3375 "setup: ignoring unsupported mode bits %x\n",
3377 spi->mode &= ~ugly_bits;
3378 bad_bits &= ~ugly_bits;
3381 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3386 if (!spi->bits_per_word)
3387 spi->bits_per_word = 8;
3389 status = __spi_validate_bits_per_word(spi->controller,
3390 spi->bits_per_word);
3394 if (spi->controller->max_speed_hz &&
3395 (!spi->max_speed_hz ||
3396 spi->max_speed_hz > spi->controller->max_speed_hz))
3397 spi->max_speed_hz = spi->controller->max_speed_hz;
3399 mutex_lock(&spi->controller->io_mutex);
3401 if (spi->controller->setup) {
3402 status = spi->controller->setup(spi);
3404 mutex_unlock(&spi->controller->io_mutex);
3405 dev_err(&spi->controller->dev, "Failed to setup device: %d\n",
3411 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
3412 status = pm_runtime_get_sync(spi->controller->dev.parent);
3414 mutex_unlock(&spi->controller->io_mutex);
3415 pm_runtime_put_noidle(spi->controller->dev.parent);
3416 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3422 * We do not want to return positive value from pm_runtime_get,
3423 * there are many instances of devices calling spi_setup() and
3424 * checking for a non-zero return value instead of a negative
3429 spi_set_cs(spi, false, true);
3430 pm_runtime_mark_last_busy(spi->controller->dev.parent);
3431 pm_runtime_put_autosuspend(spi->controller->dev.parent);
3433 spi_set_cs(spi, false, true);
3436 mutex_unlock(&spi->controller->io_mutex);
3438 if (spi->rt && !spi->controller->rt) {
3439 spi->controller->rt = true;
3440 spi_set_thread_rt(spi->controller);
3443 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3444 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
3445 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
3446 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
3447 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
3448 (spi->mode & SPI_LOOP) ? "loopback, " : "",
3449 spi->bits_per_word, spi->max_speed_hz,
3454 EXPORT_SYMBOL_GPL(spi_setup);
3457 * spi_set_cs_timing - configure CS setup, hold, and inactive delays
3458 * @spi: the device that requires specific CS timing configuration
3459 * @setup: CS setup time specified via @spi_delay
3460 * @hold: CS hold time specified via @spi_delay
3461 * @inactive: CS inactive delay between transfers specified via @spi_delay
3463 * Return: zero on success, else a negative error code.
3465 int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup,
3466 struct spi_delay *hold, struct spi_delay *inactive)
3468 struct device *parent = spi->controller->dev.parent;
3472 if (spi->controller->set_cs_timing &&
3473 !(spi->cs_gpiod || gpio_is_valid(spi->cs_gpio))) {
3474 mutex_lock(&spi->controller->io_mutex);
3476 if (spi->controller->auto_runtime_pm) {
3477 status = pm_runtime_get_sync(parent);
3479 mutex_unlock(&spi->controller->io_mutex);
3480 pm_runtime_put_noidle(parent);
3481 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3486 status = spi->controller->set_cs_timing(spi, setup,
3488 pm_runtime_mark_last_busy(parent);
3489 pm_runtime_put_autosuspend(parent);
3491 status = spi->controller->set_cs_timing(spi, setup, hold,
3495 mutex_unlock(&spi->controller->io_mutex);
3499 if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) ||
3500 (hold && hold->unit == SPI_DELAY_UNIT_SCK) ||
3501 (inactive && inactive->unit == SPI_DELAY_UNIT_SCK)) {
3503 "Clock-cycle delays for CS not supported in SW mode\n");
3507 len = sizeof(struct spi_delay);
3509 /* copy delays to controller */
3511 memcpy(&spi->controller->cs_setup, setup, len);
3513 memset(&spi->controller->cs_setup, 0, len);
3516 memcpy(&spi->controller->cs_hold, hold, len);
3518 memset(&spi->controller->cs_hold, 0, len);
3521 memcpy(&spi->controller->cs_inactive, inactive, len);
3523 memset(&spi->controller->cs_inactive, 0, len);
3527 EXPORT_SYMBOL_GPL(spi_set_cs_timing);
3529 static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
3530 struct spi_device *spi)
3534 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
3538 delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
3542 if (delay1 < delay2)
3543 memcpy(&xfer->word_delay, &spi->word_delay,
3544 sizeof(xfer->word_delay));
3549 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
3551 struct spi_controller *ctlr = spi->controller;
3552 struct spi_transfer *xfer;
3555 if (list_empty(&message->transfers))
3558 /* If an SPI controller does not support toggling the CS line on each
3559 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3560 * for the CS line, we can emulate the CS-per-word hardware function by
3561 * splitting transfers into one-word transfers and ensuring that
3562 * cs_change is set for each transfer.
3564 if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
3566 gpio_is_valid(spi->cs_gpio))) {
3570 maxsize = (spi->bits_per_word + 7) / 8;
3572 /* spi_split_transfers_maxsize() requires message->spi */
3575 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
3580 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3581 /* don't change cs_change on the last entry in the list */
3582 if (list_is_last(&xfer->transfer_list, &message->transfers))
3584 xfer->cs_change = 1;
3588 /* Half-duplex links include original MicroWire, and ones with
3589 * only one data pin like SPI_3WIRE (switches direction) or where
3590 * either MOSI or MISO is missing. They can also be caused by
3591 * software limitations.
3593 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
3594 (spi->mode & SPI_3WIRE)) {
3595 unsigned flags = ctlr->flags;
3597 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3598 if (xfer->rx_buf && xfer->tx_buf)
3600 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
3602 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
3608 * Set transfer bits_per_word and max speed as spi device default if
3609 * it is not set for this transfer.
3610 * Set transfer tx_nbits and rx_nbits as single transfer default
3611 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3612 * Ensure transfer word_delay is at least as long as that required by
3615 message->frame_length = 0;
3616 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3617 xfer->effective_speed_hz = 0;
3618 message->frame_length += xfer->len;
3619 if (!xfer->bits_per_word)
3620 xfer->bits_per_word = spi->bits_per_word;
3622 if (!xfer->speed_hz)
3623 xfer->speed_hz = spi->max_speed_hz;
3625 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
3626 xfer->speed_hz = ctlr->max_speed_hz;
3628 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
3632 * SPI transfer length should be multiple of SPI word size
3633 * where SPI word size should be power-of-two multiple
3635 if (xfer->bits_per_word <= 8)
3637 else if (xfer->bits_per_word <= 16)
3642 /* No partial transfers accepted */
3643 if (xfer->len % w_size)
3646 if (xfer->speed_hz && ctlr->min_speed_hz &&
3647 xfer->speed_hz < ctlr->min_speed_hz)
3650 if (xfer->tx_buf && !xfer->tx_nbits)
3651 xfer->tx_nbits = SPI_NBITS_SINGLE;
3652 if (xfer->rx_buf && !xfer->rx_nbits)
3653 xfer->rx_nbits = SPI_NBITS_SINGLE;
3654 /* check transfer tx/rx_nbits:
3655 * 1. check the value matches one of single, dual and quad
3656 * 2. check tx/rx_nbits match the mode in spi_device
3659 if (spi->mode & SPI_NO_TX)
3661 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3662 xfer->tx_nbits != SPI_NBITS_DUAL &&
3663 xfer->tx_nbits != SPI_NBITS_QUAD)
3665 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3666 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3668 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3669 !(spi->mode & SPI_TX_QUAD))
3672 /* check transfer rx_nbits */
3674 if (spi->mode & SPI_NO_RX)
3676 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3677 xfer->rx_nbits != SPI_NBITS_DUAL &&
3678 xfer->rx_nbits != SPI_NBITS_QUAD)
3680 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3681 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3683 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3684 !(spi->mode & SPI_RX_QUAD))
3688 if (_spi_xfer_word_delay_update(xfer, spi))
3692 message->status = -EINPROGRESS;
3697 static int __spi_async(struct spi_device *spi, struct spi_message *message)
3699 struct spi_controller *ctlr = spi->controller;
3700 struct spi_transfer *xfer;
3703 * Some controllers do not support doing regular SPI transfers. Return
3704 * ENOTSUPP when this is the case.
3706 if (!ctlr->transfer)
3711 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
3712 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3714 trace_spi_message_submit(message);
3716 if (!ctlr->ptp_sts_supported) {
3717 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3718 xfer->ptp_sts_word_pre = 0;
3719 ptp_read_system_prets(xfer->ptp_sts);
3723 return ctlr->transfer(spi, message);
3727 * spi_async - asynchronous SPI transfer
3728 * @spi: device with which data will be exchanged
3729 * @message: describes the data transfers, including completion callback
3730 * Context: any (irqs may be blocked, etc)
3732 * This call may be used in_irq and other contexts which can't sleep,
3733 * as well as from task contexts which can sleep.
3735 * The completion callback is invoked in a context which can't sleep.
3736 * Before that invocation, the value of message->status is undefined.
3737 * When the callback is issued, message->status holds either zero (to
3738 * indicate complete success) or a negative error code. After that
3739 * callback returns, the driver which issued the transfer request may
3740 * deallocate the associated memory; it's no longer in use by any SPI
3741 * core or controller driver code.
3743 * Note that although all messages to a spi_device are handled in
3744 * FIFO order, messages may go to different devices in other orders.
3745 * Some device might be higher priority, or have various "hard" access
3746 * time requirements, for example.
3748 * On detection of any fault during the transfer, processing of
3749 * the entire message is aborted, and the device is deselected.
3750 * Until returning from the associated message completion callback,
3751 * no other spi_message queued to that device will be processed.
3752 * (This rule applies equally to all the synchronous transfer calls,
3753 * which are wrappers around this core asynchronous primitive.)
3755 * Return: zero on success, else a negative error code.
3757 int spi_async(struct spi_device *spi, struct spi_message *message)
3759 struct spi_controller *ctlr = spi->controller;
3761 unsigned long flags;
3763 ret = __spi_validate(spi, message);
3767 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3769 if (ctlr->bus_lock_flag)
3772 ret = __spi_async(spi, message);
3774 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3778 EXPORT_SYMBOL_GPL(spi_async);
3781 * spi_async_locked - version of spi_async with exclusive bus usage
3782 * @spi: device with which data will be exchanged
3783 * @message: describes the data transfers, including completion callback
3784 * Context: any (irqs may be blocked, etc)
3786 * This call may be used in_irq and other contexts which can't sleep,
3787 * as well as from task contexts which can sleep.
3789 * The completion callback is invoked in a context which can't sleep.
3790 * Before that invocation, the value of message->status is undefined.
3791 * When the callback is issued, message->status holds either zero (to
3792 * indicate complete success) or a negative error code. After that
3793 * callback returns, the driver which issued the transfer request may
3794 * deallocate the associated memory; it's no longer in use by any SPI
3795 * core or controller driver code.
3797 * Note that although all messages to a spi_device are handled in
3798 * FIFO order, messages may go to different devices in other orders.
3799 * Some device might be higher priority, or have various "hard" access
3800 * time requirements, for example.
3802 * On detection of any fault during the transfer, processing of
3803 * the entire message is aborted, and the device is deselected.
3804 * Until returning from the associated message completion callback,
3805 * no other spi_message queued to that device will be processed.
3806 * (This rule applies equally to all the synchronous transfer calls,
3807 * which are wrappers around this core asynchronous primitive.)
3809 * Return: zero on success, else a negative error code.
3811 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3813 struct spi_controller *ctlr = spi->controller;
3815 unsigned long flags;
3817 ret = __spi_validate(spi, message);
3821 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3823 ret = __spi_async(spi, message);
3825 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3830 EXPORT_SYMBOL_GPL(spi_async_locked);
3832 /*-------------------------------------------------------------------------*/
3834 /* Utility methods for SPI protocol drivers, layered on
3835 * top of the core. Some other utility methods are defined as
3839 static void spi_complete(void *arg)
3844 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3846 DECLARE_COMPLETION_ONSTACK(done);
3848 struct spi_controller *ctlr = spi->controller;
3849 unsigned long flags;
3851 status = __spi_validate(spi, message);
3855 message->complete = spi_complete;
3856 message->context = &done;
3859 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3860 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3862 /* If we're not using the legacy transfer method then we will
3863 * try to transfer in the calling context so special case.
3864 * This code would be less tricky if we could remove the
3865 * support for driver implemented message queues.
3867 if (ctlr->transfer == spi_queued_transfer) {
3868 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3870 trace_spi_message_submit(message);
3872 status = __spi_queued_transfer(spi, message, false);
3874 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3876 status = spi_async_locked(spi, message);
3880 /* Push out the messages in the calling context if we
3883 if (ctlr->transfer == spi_queued_transfer) {
3884 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3885 spi_sync_immediate);
3886 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3887 spi_sync_immediate);
3888 __spi_pump_messages(ctlr, false);
3891 wait_for_completion(&done);
3892 status = message->status;
3894 message->context = NULL;
3899 * spi_sync - blocking/synchronous SPI data transfers
3900 * @spi: device with which data will be exchanged
3901 * @message: describes the data transfers
3902 * Context: can sleep
3904 * This call may only be used from a context that may sleep. The sleep
3905 * is non-interruptible, and has no timeout. Low-overhead controller
3906 * drivers may DMA directly into and out of the message buffers.
3908 * Note that the SPI device's chip select is active during the message,
3909 * and then is normally disabled between messages. Drivers for some
3910 * frequently-used devices may want to minimize costs of selecting a chip,
3911 * by leaving it selected in anticipation that the next message will go
3912 * to the same chip. (That may increase power usage.)
3914 * Also, the caller is guaranteeing that the memory associated with the
3915 * message will not be freed before this call returns.
3917 * Return: zero on success, else a negative error code.
3919 int spi_sync(struct spi_device *spi, struct spi_message *message)
3923 mutex_lock(&spi->controller->bus_lock_mutex);
3924 ret = __spi_sync(spi, message);
3925 mutex_unlock(&spi->controller->bus_lock_mutex);
3929 EXPORT_SYMBOL_GPL(spi_sync);
3932 * spi_sync_locked - version of spi_sync with exclusive bus usage
3933 * @spi: device with which data will be exchanged
3934 * @message: describes the data transfers
3935 * Context: can sleep
3937 * This call may only be used from a context that may sleep. The sleep
3938 * is non-interruptible, and has no timeout. Low-overhead controller
3939 * drivers may DMA directly into and out of the message buffers.
3941 * This call should be used by drivers that require exclusive access to the
3942 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3943 * be released by a spi_bus_unlock call when the exclusive access is over.
3945 * Return: zero on success, else a negative error code.
3947 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3949 return __spi_sync(spi, message);
3951 EXPORT_SYMBOL_GPL(spi_sync_locked);
3954 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3955 * @ctlr: SPI bus master that should be locked for exclusive bus access
3956 * Context: can sleep
3958 * This call may only be used from a context that may sleep. The sleep
3959 * is non-interruptible, and has no timeout.
3961 * This call should be used by drivers that require exclusive access to the
3962 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3963 * exclusive access is over. Data transfer must be done by spi_sync_locked
3964 * and spi_async_locked calls when the SPI bus lock is held.
3966 * Return: always zero.
3968 int spi_bus_lock(struct spi_controller *ctlr)
3970 unsigned long flags;
3972 mutex_lock(&ctlr->bus_lock_mutex);
3974 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3975 ctlr->bus_lock_flag = 1;
3976 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3978 /* mutex remains locked until spi_bus_unlock is called */
3982 EXPORT_SYMBOL_GPL(spi_bus_lock);
3985 * spi_bus_unlock - release the lock for exclusive SPI bus usage
3986 * @ctlr: SPI bus master that was locked for exclusive bus access
3987 * Context: can sleep
3989 * This call may only be used from a context that may sleep. The sleep
3990 * is non-interruptible, and has no timeout.
3992 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3995 * Return: always zero.
3997 int spi_bus_unlock(struct spi_controller *ctlr)
3999 ctlr->bus_lock_flag = 0;
4001 mutex_unlock(&ctlr->bus_lock_mutex);
4005 EXPORT_SYMBOL_GPL(spi_bus_unlock);
4007 /* portable code must never pass more than 32 bytes */
4008 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
4013 * spi_write_then_read - SPI synchronous write followed by read
4014 * @spi: device with which data will be exchanged
4015 * @txbuf: data to be written (need not be dma-safe)
4016 * @n_tx: size of txbuf, in bytes
4017 * @rxbuf: buffer into which data will be read (need not be dma-safe)
4018 * @n_rx: size of rxbuf, in bytes
4019 * Context: can sleep
4021 * This performs a half duplex MicroWire style transaction with the
4022 * device, sending txbuf and then reading rxbuf. The return value
4023 * is zero for success, else a negative errno status code.
4024 * This call may only be used from a context that may sleep.
4026 * Parameters to this routine are always copied using a small buffer.
4027 * Performance-sensitive or bulk transfer code should instead use
4028 * spi_{async,sync}() calls with dma-safe buffers.
4030 * Return: zero on success, else a negative error code.
4032 int spi_write_then_read(struct spi_device *spi,
4033 const void *txbuf, unsigned n_tx,
4034 void *rxbuf, unsigned n_rx)
4036 static DEFINE_MUTEX(lock);
4039 struct spi_message message;
4040 struct spi_transfer x[2];
4043 /* Use preallocated DMA-safe buffer if we can. We can't avoid
4044 * copying here, (as a pure convenience thing), but we can
4045 * keep heap costs out of the hot path unless someone else is
4046 * using the pre-allocated buffer or the transfer is too large.
4048 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
4049 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
4050 GFP_KERNEL | GFP_DMA);
4057 spi_message_init(&message);
4058 memset(x, 0, sizeof(x));
4061 spi_message_add_tail(&x[0], &message);
4065 spi_message_add_tail(&x[1], &message);
4068 memcpy(local_buf, txbuf, n_tx);
4069 x[0].tx_buf = local_buf;
4070 x[1].rx_buf = local_buf + n_tx;
4073 status = spi_sync(spi, &message);
4075 memcpy(rxbuf, x[1].rx_buf, n_rx);
4077 if (x[0].tx_buf == buf)
4078 mutex_unlock(&lock);
4084 EXPORT_SYMBOL_GPL(spi_write_then_read);
4086 /*-------------------------------------------------------------------------*/
4088 #if IS_ENABLED(CONFIG_OF)
4089 /* must call put_device() when done with returned spi_device device */
4090 struct spi_device *of_find_spi_device_by_node(struct device_node *node)
4092 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
4094 return dev ? to_spi_device(dev) : NULL;
4096 EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
4097 #endif /* IS_ENABLED(CONFIG_OF) */
4099 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
4100 /* the spi controllers are not using spi_bus, so we find it with another way */
4101 static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
4105 dev = class_find_device_by_of_node(&spi_master_class, node);
4106 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4107 dev = class_find_device_by_of_node(&spi_slave_class, node);
4111 /* reference got in class_find_device */
4112 return container_of(dev, struct spi_controller, dev);
4115 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
4118 struct of_reconfig_data *rd = arg;
4119 struct spi_controller *ctlr;
4120 struct spi_device *spi;
4122 switch (of_reconfig_get_state_change(action, arg)) {
4123 case OF_RECONFIG_CHANGE_ADD:
4124 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
4126 return NOTIFY_OK; /* not for us */
4128 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
4129 put_device(&ctlr->dev);
4133 spi = of_register_spi_device(ctlr, rd->dn);
4134 put_device(&ctlr->dev);
4137 pr_err("%s: failed to create for '%pOF'\n",
4139 of_node_clear_flag(rd->dn, OF_POPULATED);
4140 return notifier_from_errno(PTR_ERR(spi));
4144 case OF_RECONFIG_CHANGE_REMOVE:
4145 /* already depopulated? */
4146 if (!of_node_check_flag(rd->dn, OF_POPULATED))
4149 /* find our device by node */
4150 spi = of_find_spi_device_by_node(rd->dn);
4152 return NOTIFY_OK; /* no? not meant for us */
4154 /* unregister takes one ref away */
4155 spi_unregister_device(spi);
4157 /* and put the reference of the find */
4158 put_device(&spi->dev);
4165 static struct notifier_block spi_of_notifier = {
4166 .notifier_call = of_spi_notify,
4168 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4169 extern struct notifier_block spi_of_notifier;
4170 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4172 #if IS_ENABLED(CONFIG_ACPI)
4173 static int spi_acpi_controller_match(struct device *dev, const void *data)
4175 return ACPI_COMPANION(dev->parent) == data;
4178 static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4182 dev = class_find_device(&spi_master_class, NULL, adev,
4183 spi_acpi_controller_match);
4184 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4185 dev = class_find_device(&spi_slave_class, NULL, adev,
4186 spi_acpi_controller_match);
4190 return container_of(dev, struct spi_controller, dev);
4193 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4197 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4198 return to_spi_device(dev);
4201 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4204 struct acpi_device *adev = arg;
4205 struct spi_controller *ctlr;
4206 struct spi_device *spi;
4209 case ACPI_RECONFIG_DEVICE_ADD:
4210 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
4214 acpi_register_spi_device(ctlr, adev);
4215 put_device(&ctlr->dev);
4217 case ACPI_RECONFIG_DEVICE_REMOVE:
4218 if (!acpi_device_enumerated(adev))
4221 spi = acpi_spi_find_device_by_adev(adev);
4225 spi_unregister_device(spi);
4226 put_device(&spi->dev);
4233 static struct notifier_block spi_acpi_notifier = {
4234 .notifier_call = acpi_spi_notify,
4237 extern struct notifier_block spi_acpi_notifier;
4240 static int __init spi_init(void)
4244 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4250 status = bus_register(&spi_bus_type);
4254 status = class_register(&spi_master_class);
4258 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4259 status = class_register(&spi_slave_class);
4264 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4265 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4266 if (IS_ENABLED(CONFIG_ACPI))
4267 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4272 class_unregister(&spi_master_class);
4274 bus_unregister(&spi_bus_type);
4282 /* board_info is normally registered in arch_initcall(),
4283 * but even essential drivers wait till later
4285 * REVISIT only boardinfo really needs static linking. the rest (device and
4286 * driver registration) _could_ be dynamically linked (modular) ... costs
4287 * include needing to have boardinfo data structures be much more public.
4289 postcore_initcall(spi_init);