4 * Copyright (C) 2005 David Brownell
5 * Copyright (C) 2008 Secret Lab Technologies Ltd.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
18 #include <linux/kernel.h>
19 #include <linux/device.h>
20 #include <linux/init.h>
21 #include <linux/cache.h>
22 #include <linux/dma-mapping.h>
23 #include <linux/dmaengine.h>
24 #include <linux/mutex.h>
25 #include <linux/of_device.h>
26 #include <linux/of_irq.h>
27 #include <linux/clk/clk-conf.h>
28 #include <linux/slab.h>
29 #include <linux/mod_devicetable.h>
30 #include <linux/spi/spi.h>
31 #include <linux/spi/spi-mem.h>
32 #include <linux/of_gpio.h>
33 #include <linux/pm_runtime.h>
34 #include <linux/pm_domain.h>
35 #include <linux/property.h>
36 #include <linux/export.h>
37 #include <linux/sched/rt.h>
38 #include <uapi/linux/sched/types.h>
39 #include <linux/delay.h>
40 #include <linux/kthread.h>
41 #include <linux/ioport.h>
42 #include <linux/acpi.h>
43 #include <linux/highmem.h>
44 #include <linux/idr.h>
45 #include <linux/platform_data/x86/apple.h>
47 #define CREATE_TRACE_POINTS
48 #include <trace/events/spi.h>
50 #include "internals.h"
52 static DEFINE_IDR(spi_master_idr);
54 static void spidev_release(struct device *dev)
56 struct spi_device *spi = to_spi_device(dev);
58 /* spi controllers may cleanup for released devices */
59 if (spi->controller->cleanup)
60 spi->controller->cleanup(spi);
62 spi_controller_put(spi->controller);
67 modalias_show(struct device *dev, struct device_attribute *a, char *buf)
69 const struct spi_device *spi = to_spi_device(dev);
72 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
76 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
78 static DEVICE_ATTR_RO(modalias);
80 #define SPI_STATISTICS_ATTRS(field, file) \
81 static ssize_t spi_controller_##field##_show(struct device *dev, \
82 struct device_attribute *attr, \
85 struct spi_controller *ctlr = container_of(dev, \
86 struct spi_controller, dev); \
87 return spi_statistics_##field##_show(&ctlr->statistics, buf); \
89 static struct device_attribute dev_attr_spi_controller_##field = { \
90 .attr = { .name = file, .mode = 0444 }, \
91 .show = spi_controller_##field##_show, \
93 static ssize_t spi_device_##field##_show(struct device *dev, \
94 struct device_attribute *attr, \
97 struct spi_device *spi = to_spi_device(dev); \
98 return spi_statistics_##field##_show(&spi->statistics, buf); \
100 static struct device_attribute dev_attr_spi_device_##field = { \
101 .attr = { .name = file, .mode = 0444 }, \
102 .show = spi_device_##field##_show, \
105 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
106 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
109 unsigned long flags; \
111 spin_lock_irqsave(&stat->lock, flags); \
112 len = sprintf(buf, format_string, stat->field); \
113 spin_unlock_irqrestore(&stat->lock, flags); \
116 SPI_STATISTICS_ATTRS(name, file)
118 #define SPI_STATISTICS_SHOW(field, format_string) \
119 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
120 field, format_string)
122 SPI_STATISTICS_SHOW(messages, "%lu");
123 SPI_STATISTICS_SHOW(transfers, "%lu");
124 SPI_STATISTICS_SHOW(errors, "%lu");
125 SPI_STATISTICS_SHOW(timedout, "%lu");
127 SPI_STATISTICS_SHOW(spi_sync, "%lu");
128 SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
129 SPI_STATISTICS_SHOW(spi_async, "%lu");
131 SPI_STATISTICS_SHOW(bytes, "%llu");
132 SPI_STATISTICS_SHOW(bytes_rx, "%llu");
133 SPI_STATISTICS_SHOW(bytes_tx, "%llu");
135 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
136 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
137 "transfer_bytes_histo_" number, \
138 transfer_bytes_histo[index], "%lu")
139 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
140 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
141 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
142 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
143 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
144 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
145 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
146 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
147 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
148 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
149 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
150 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
151 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
152 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
153 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
154 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
155 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
157 SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
159 static struct attribute *spi_dev_attrs[] = {
160 &dev_attr_modalias.attr,
164 static const struct attribute_group spi_dev_group = {
165 .attrs = spi_dev_attrs,
168 static struct attribute *spi_device_statistics_attrs[] = {
169 &dev_attr_spi_device_messages.attr,
170 &dev_attr_spi_device_transfers.attr,
171 &dev_attr_spi_device_errors.attr,
172 &dev_attr_spi_device_timedout.attr,
173 &dev_attr_spi_device_spi_sync.attr,
174 &dev_attr_spi_device_spi_sync_immediate.attr,
175 &dev_attr_spi_device_spi_async.attr,
176 &dev_attr_spi_device_bytes.attr,
177 &dev_attr_spi_device_bytes_rx.attr,
178 &dev_attr_spi_device_bytes_tx.attr,
179 &dev_attr_spi_device_transfer_bytes_histo0.attr,
180 &dev_attr_spi_device_transfer_bytes_histo1.attr,
181 &dev_attr_spi_device_transfer_bytes_histo2.attr,
182 &dev_attr_spi_device_transfer_bytes_histo3.attr,
183 &dev_attr_spi_device_transfer_bytes_histo4.attr,
184 &dev_attr_spi_device_transfer_bytes_histo5.attr,
185 &dev_attr_spi_device_transfer_bytes_histo6.attr,
186 &dev_attr_spi_device_transfer_bytes_histo7.attr,
187 &dev_attr_spi_device_transfer_bytes_histo8.attr,
188 &dev_attr_spi_device_transfer_bytes_histo9.attr,
189 &dev_attr_spi_device_transfer_bytes_histo10.attr,
190 &dev_attr_spi_device_transfer_bytes_histo11.attr,
191 &dev_attr_spi_device_transfer_bytes_histo12.attr,
192 &dev_attr_spi_device_transfer_bytes_histo13.attr,
193 &dev_attr_spi_device_transfer_bytes_histo14.attr,
194 &dev_attr_spi_device_transfer_bytes_histo15.attr,
195 &dev_attr_spi_device_transfer_bytes_histo16.attr,
196 &dev_attr_spi_device_transfers_split_maxsize.attr,
200 static const struct attribute_group spi_device_statistics_group = {
201 .name = "statistics",
202 .attrs = spi_device_statistics_attrs,
205 static const struct attribute_group *spi_dev_groups[] = {
207 &spi_device_statistics_group,
211 static struct attribute *spi_controller_statistics_attrs[] = {
212 &dev_attr_spi_controller_messages.attr,
213 &dev_attr_spi_controller_transfers.attr,
214 &dev_attr_spi_controller_errors.attr,
215 &dev_attr_spi_controller_timedout.attr,
216 &dev_attr_spi_controller_spi_sync.attr,
217 &dev_attr_spi_controller_spi_sync_immediate.attr,
218 &dev_attr_spi_controller_spi_async.attr,
219 &dev_attr_spi_controller_bytes.attr,
220 &dev_attr_spi_controller_bytes_rx.attr,
221 &dev_attr_spi_controller_bytes_tx.attr,
222 &dev_attr_spi_controller_transfer_bytes_histo0.attr,
223 &dev_attr_spi_controller_transfer_bytes_histo1.attr,
224 &dev_attr_spi_controller_transfer_bytes_histo2.attr,
225 &dev_attr_spi_controller_transfer_bytes_histo3.attr,
226 &dev_attr_spi_controller_transfer_bytes_histo4.attr,
227 &dev_attr_spi_controller_transfer_bytes_histo5.attr,
228 &dev_attr_spi_controller_transfer_bytes_histo6.attr,
229 &dev_attr_spi_controller_transfer_bytes_histo7.attr,
230 &dev_attr_spi_controller_transfer_bytes_histo8.attr,
231 &dev_attr_spi_controller_transfer_bytes_histo9.attr,
232 &dev_attr_spi_controller_transfer_bytes_histo10.attr,
233 &dev_attr_spi_controller_transfer_bytes_histo11.attr,
234 &dev_attr_spi_controller_transfer_bytes_histo12.attr,
235 &dev_attr_spi_controller_transfer_bytes_histo13.attr,
236 &dev_attr_spi_controller_transfer_bytes_histo14.attr,
237 &dev_attr_spi_controller_transfer_bytes_histo15.attr,
238 &dev_attr_spi_controller_transfer_bytes_histo16.attr,
239 &dev_attr_spi_controller_transfers_split_maxsize.attr,
243 static const struct attribute_group spi_controller_statistics_group = {
244 .name = "statistics",
245 .attrs = spi_controller_statistics_attrs,
248 static const struct attribute_group *spi_master_groups[] = {
249 &spi_controller_statistics_group,
253 void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
254 struct spi_transfer *xfer,
255 struct spi_controller *ctlr)
258 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
263 spin_lock_irqsave(&stats->lock, flags);
266 stats->transfer_bytes_histo[l2len]++;
268 stats->bytes += xfer->len;
269 if ((xfer->tx_buf) &&
270 (xfer->tx_buf != ctlr->dummy_tx))
271 stats->bytes_tx += xfer->len;
272 if ((xfer->rx_buf) &&
273 (xfer->rx_buf != ctlr->dummy_rx))
274 stats->bytes_rx += xfer->len;
276 spin_unlock_irqrestore(&stats->lock, flags);
278 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
280 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
281 * and the sysfs version makes coldplug work too.
284 static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
285 const struct spi_device *sdev)
287 while (id->name[0]) {
288 if (!strcmp(sdev->modalias, id->name))
295 const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
297 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
299 return spi_match_id(sdrv->id_table, sdev);
301 EXPORT_SYMBOL_GPL(spi_get_device_id);
303 static int spi_match_device(struct device *dev, struct device_driver *drv)
305 const struct spi_device *spi = to_spi_device(dev);
306 const struct spi_driver *sdrv = to_spi_driver(drv);
308 /* Attempt an OF style match */
309 if (of_driver_match_device(dev, drv))
313 if (acpi_driver_match_device(dev, drv))
317 return !!spi_match_id(sdrv->id_table, spi);
319 return strcmp(spi->modalias, drv->name) == 0;
322 static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
324 const struct spi_device *spi = to_spi_device(dev);
327 rc = acpi_device_uevent_modalias(dev, env);
331 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
334 struct bus_type spi_bus_type = {
336 .dev_groups = spi_dev_groups,
337 .match = spi_match_device,
338 .uevent = spi_uevent,
340 EXPORT_SYMBOL_GPL(spi_bus_type);
343 static int spi_drv_probe(struct device *dev)
345 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
346 struct spi_device *spi = to_spi_device(dev);
349 ret = of_clk_set_defaults(dev->of_node, false);
354 spi->irq = of_irq_get(dev->of_node, 0);
355 if (spi->irq == -EPROBE_DEFER)
356 return -EPROBE_DEFER;
361 ret = dev_pm_domain_attach(dev, true);
366 ret = sdrv->probe(spi);
368 dev_pm_domain_detach(dev, true);
374 static int spi_drv_remove(struct device *dev)
376 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
380 ret = sdrv->remove(to_spi_device(dev));
381 dev_pm_domain_detach(dev, true);
386 static void spi_drv_shutdown(struct device *dev)
388 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
390 sdrv->shutdown(to_spi_device(dev));
394 * __spi_register_driver - register a SPI driver
395 * @owner: owner module of the driver to register
396 * @sdrv: the driver to register
399 * Return: zero on success, else a negative error code.
401 int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
403 sdrv->driver.owner = owner;
404 sdrv->driver.bus = &spi_bus_type;
405 sdrv->driver.probe = spi_drv_probe;
406 sdrv->driver.remove = spi_drv_remove;
408 sdrv->driver.shutdown = spi_drv_shutdown;
409 return driver_register(&sdrv->driver);
411 EXPORT_SYMBOL_GPL(__spi_register_driver);
413 /*-------------------------------------------------------------------------*/
415 /* SPI devices should normally not be created by SPI device drivers; that
416 * would make them board-specific. Similarly with SPI controller drivers.
417 * Device registration normally goes into like arch/.../mach.../board-YYY.c
418 * with other readonly (flashable) information about mainboard devices.
422 struct list_head list;
423 struct spi_board_info board_info;
426 static LIST_HEAD(board_list);
427 static LIST_HEAD(spi_controller_list);
430 * Used to protect add/del opertion for board_info list and
431 * spi_controller list, and their matching process
432 * also used to protect object of type struct idr
434 static DEFINE_MUTEX(board_lock);
437 * Prevents addition of devices with same chip select and
438 * addition of devices below an unregistering controller.
440 static DEFINE_MUTEX(spi_add_lock);
443 * spi_alloc_device - Allocate a new SPI device
444 * @ctlr: Controller to which device is connected
447 * Allows a driver to allocate and initialize a spi_device without
448 * registering it immediately. This allows a driver to directly
449 * fill the spi_device with device parameters before calling
450 * spi_add_device() on it.
452 * Caller is responsible to call spi_add_device() on the returned
453 * spi_device structure to add it to the SPI controller. If the caller
454 * needs to discard the spi_device without adding it, then it should
455 * call spi_dev_put() on it.
457 * Return: a pointer to the new device, or NULL.
459 struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
461 struct spi_device *spi;
463 if (!spi_controller_get(ctlr))
466 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
468 spi_controller_put(ctlr);
472 spi->master = spi->controller = ctlr;
473 spi->dev.parent = &ctlr->dev;
474 spi->dev.bus = &spi_bus_type;
475 spi->dev.release = spidev_release;
476 spi->cs_gpio = -ENOENT;
478 spin_lock_init(&spi->statistics.lock);
480 device_initialize(&spi->dev);
483 EXPORT_SYMBOL_GPL(spi_alloc_device);
485 static void spi_dev_set_name(struct spi_device *spi)
487 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
490 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
494 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
498 static int spi_dev_check(struct device *dev, void *data)
500 struct spi_device *spi = to_spi_device(dev);
501 struct spi_device *new_spi = data;
503 if (spi->controller == new_spi->controller &&
504 spi->chip_select == new_spi->chip_select)
510 * spi_add_device - Add spi_device allocated with spi_alloc_device
511 * @spi: spi_device to register
513 * Companion function to spi_alloc_device. Devices allocated with
514 * spi_alloc_device can be added onto the spi bus with this function.
516 * Return: 0 on success; negative errno on failure
518 int spi_add_device(struct spi_device *spi)
520 struct spi_controller *ctlr = spi->controller;
521 struct device *dev = ctlr->dev.parent;
524 /* Chipselects are numbered 0..max; validate. */
525 if (spi->chip_select >= ctlr->num_chipselect) {
526 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
527 ctlr->num_chipselect);
531 /* Set the bus ID string */
532 spi_dev_set_name(spi);
534 /* We need to make sure there's no other device with this
535 * chipselect **BEFORE** we call setup(), else we'll trash
536 * its configuration. Lock against concurrent add() calls.
538 mutex_lock(&spi_add_lock);
540 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
542 dev_err(dev, "chipselect %d already in use\n",
547 /* Controller may unregister concurrently */
548 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
549 !device_is_registered(&ctlr->dev)) {
555 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
557 /* Drivers may modify this initial i/o setup, but will
558 * normally rely on the device being setup. Devices
559 * using SPI_CS_HIGH can't coexist well otherwise...
561 status = spi_setup(spi);
563 dev_err(dev, "can't setup %s, status %d\n",
564 dev_name(&spi->dev), status);
568 /* Device may be bound to an active driver when this returns */
569 status = device_add(&spi->dev);
571 dev_err(dev, "can't add %s, status %d\n",
572 dev_name(&spi->dev), status);
574 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
577 mutex_unlock(&spi_add_lock);
580 EXPORT_SYMBOL_GPL(spi_add_device);
583 * spi_new_device - instantiate one new SPI device
584 * @ctlr: Controller to which device is connected
585 * @chip: Describes the SPI device
588 * On typical mainboards, this is purely internal; and it's not needed
589 * after board init creates the hard-wired devices. Some development
590 * platforms may not be able to use spi_register_board_info though, and
591 * this is exported so that for example a USB or parport based adapter
592 * driver could add devices (which it would learn about out-of-band).
594 * Return: the new device, or NULL.
596 struct spi_device *spi_new_device(struct spi_controller *ctlr,
597 struct spi_board_info *chip)
599 struct spi_device *proxy;
602 /* NOTE: caller did any chip->bus_num checks necessary.
604 * Also, unless we change the return value convention to use
605 * error-or-pointer (not NULL-or-pointer), troubleshootability
606 * suggests syslogged diagnostics are best here (ugh).
609 proxy = spi_alloc_device(ctlr);
613 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
615 proxy->chip_select = chip->chip_select;
616 proxy->max_speed_hz = chip->max_speed_hz;
617 proxy->mode = chip->mode;
618 proxy->irq = chip->irq;
619 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
620 proxy->dev.platform_data = (void *) chip->platform_data;
621 proxy->controller_data = chip->controller_data;
622 proxy->controller_state = NULL;
624 if (chip->properties) {
625 status = device_add_properties(&proxy->dev, chip->properties);
628 "failed to add properties to '%s': %d\n",
629 chip->modalias, status);
634 status = spi_add_device(proxy);
636 goto err_remove_props;
641 if (chip->properties)
642 device_remove_properties(&proxy->dev);
647 EXPORT_SYMBOL_GPL(spi_new_device);
650 * spi_unregister_device - unregister a single SPI device
651 * @spi: spi_device to unregister
653 * Start making the passed SPI device vanish. Normally this would be handled
654 * by spi_unregister_controller().
656 void spi_unregister_device(struct spi_device *spi)
661 if (spi->dev.of_node) {
662 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
663 of_node_put(spi->dev.of_node);
665 if (ACPI_COMPANION(&spi->dev))
666 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
667 device_unregister(&spi->dev);
669 EXPORT_SYMBOL_GPL(spi_unregister_device);
671 static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
672 struct spi_board_info *bi)
674 struct spi_device *dev;
676 if (ctlr->bus_num != bi->bus_num)
679 dev = spi_new_device(ctlr, bi);
681 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
686 * spi_register_board_info - register SPI devices for a given board
687 * @info: array of chip descriptors
688 * @n: how many descriptors are provided
691 * Board-specific early init code calls this (probably during arch_initcall)
692 * with segments of the SPI device table. Any device nodes are created later,
693 * after the relevant parent SPI controller (bus_num) is defined. We keep
694 * this table of devices forever, so that reloading a controller driver will
695 * not make Linux forget about these hard-wired devices.
697 * Other code can also call this, e.g. a particular add-on board might provide
698 * SPI devices through its expansion connector, so code initializing that board
699 * would naturally declare its SPI devices.
701 * The board info passed can safely be __initdata ... but be careful of
702 * any embedded pointers (platform_data, etc), they're copied as-is.
703 * Device properties are deep-copied though.
705 * Return: zero on success, else a negative error code.
707 int spi_register_board_info(struct spi_board_info const *info, unsigned n)
709 struct boardinfo *bi;
715 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
719 for (i = 0; i < n; i++, bi++, info++) {
720 struct spi_controller *ctlr;
722 memcpy(&bi->board_info, info, sizeof(*info));
723 if (info->properties) {
724 bi->board_info.properties =
725 property_entries_dup(info->properties);
726 if (IS_ERR(bi->board_info.properties))
727 return PTR_ERR(bi->board_info.properties);
730 mutex_lock(&board_lock);
731 list_add_tail(&bi->list, &board_list);
732 list_for_each_entry(ctlr, &spi_controller_list, list)
733 spi_match_controller_to_boardinfo(ctlr,
735 mutex_unlock(&board_lock);
741 /*-------------------------------------------------------------------------*/
743 static void spi_set_cs(struct spi_device *spi, bool enable)
745 if (spi->mode & SPI_CS_HIGH)
748 if (gpio_is_valid(spi->cs_gpio)) {
749 gpio_set_value(spi->cs_gpio, !enable);
750 /* Some SPI masters need both GPIO CS & slave_select */
751 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
752 spi->controller->set_cs)
753 spi->controller->set_cs(spi, !enable);
754 } else if (spi->controller->set_cs) {
755 spi->controller->set_cs(spi, !enable);
759 #ifdef CONFIG_HAS_DMA
760 int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
761 struct sg_table *sgt, void *buf, size_t len,
762 enum dma_data_direction dir)
764 const bool vmalloced_buf = is_vmalloc_addr(buf);
765 unsigned int max_seg_size = dma_get_max_seg_size(dev);
766 #ifdef CONFIG_HIGHMEM
767 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
768 (unsigned long)buf < (PKMAP_BASE +
769 (LAST_PKMAP * PAGE_SIZE)));
771 const bool kmap_buf = false;
775 struct page *vm_page;
776 struct scatterlist *sg;
781 if (vmalloced_buf || kmap_buf) {
782 desc_len = min_t(unsigned long, max_seg_size, PAGE_SIZE);
783 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
784 } else if (virt_addr_valid(buf)) {
785 desc_len = min_t(size_t, max_seg_size, ctlr->max_dma_len);
786 sgs = DIV_ROUND_UP(len, desc_len);
791 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
796 for (i = 0; i < sgs; i++) {
798 if (vmalloced_buf || kmap_buf) {
800 * Next scatterlist entry size is the minimum between
801 * the desc_len and the remaining buffer length that
804 min = min_t(size_t, desc_len,
806 PAGE_SIZE - offset_in_page(buf)));
808 vm_page = vmalloc_to_page(buf);
810 vm_page = kmap_to_page(buf);
815 sg_set_page(sg, vm_page,
816 min, offset_in_page(buf));
818 min = min_t(size_t, len, desc_len);
820 sg_set_buf(sg, sg_buf, min);
828 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
841 void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
842 struct sg_table *sgt, enum dma_data_direction dir)
844 if (sgt->orig_nents) {
845 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
850 static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
852 struct device *tx_dev, *rx_dev;
853 struct spi_transfer *xfer;
860 tx_dev = ctlr->dma_tx->device->dev;
862 tx_dev = ctlr->dev.parent;
865 rx_dev = ctlr->dma_rx->device->dev;
867 rx_dev = ctlr->dev.parent;
869 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
870 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
873 if (xfer->tx_buf != NULL) {
874 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
875 (void *)xfer->tx_buf, xfer->len,
881 if (xfer->rx_buf != NULL) {
882 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
883 xfer->rx_buf, xfer->len,
886 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
893 ctlr->cur_msg_mapped = true;
898 static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
900 struct spi_transfer *xfer;
901 struct device *tx_dev, *rx_dev;
903 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
907 tx_dev = ctlr->dma_tx->device->dev;
909 tx_dev = ctlr->dev.parent;
912 rx_dev = ctlr->dma_rx->device->dev;
914 rx_dev = ctlr->dev.parent;
916 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
917 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
920 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
921 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
926 #else /* !CONFIG_HAS_DMA */
927 static inline int __spi_map_msg(struct spi_controller *ctlr,
928 struct spi_message *msg)
933 static inline int __spi_unmap_msg(struct spi_controller *ctlr,
934 struct spi_message *msg)
938 #endif /* !CONFIG_HAS_DMA */
940 static inline int spi_unmap_msg(struct spi_controller *ctlr,
941 struct spi_message *msg)
943 struct spi_transfer *xfer;
945 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
947 * Restore the original value of tx_buf or rx_buf if they are
950 if (xfer->tx_buf == ctlr->dummy_tx)
952 if (xfer->rx_buf == ctlr->dummy_rx)
956 return __spi_unmap_msg(ctlr, msg);
959 static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
961 struct spi_transfer *xfer;
963 unsigned int max_tx, max_rx;
965 if (ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) {
969 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
970 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
972 max_tx = max(xfer->len, max_tx);
973 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
975 max_rx = max(xfer->len, max_rx);
979 tmp = krealloc(ctlr->dummy_tx, max_tx,
980 GFP_KERNEL | GFP_DMA);
983 ctlr->dummy_tx = tmp;
984 memset(tmp, 0, max_tx);
988 tmp = krealloc(ctlr->dummy_rx, max_rx,
989 GFP_KERNEL | GFP_DMA);
992 ctlr->dummy_rx = tmp;
995 if (max_tx || max_rx) {
996 list_for_each_entry(xfer, &msg->transfers,
1001 xfer->tx_buf = ctlr->dummy_tx;
1003 xfer->rx_buf = ctlr->dummy_rx;
1008 return __spi_map_msg(ctlr, msg);
1012 * spi_transfer_one_message - Default implementation of transfer_one_message()
1014 * This is a standard implementation of transfer_one_message() for
1015 * drivers which implement a transfer_one() operation. It provides
1016 * standard handling of delays and chip select management.
1018 static int spi_transfer_one_message(struct spi_controller *ctlr,
1019 struct spi_message *msg)
1021 struct spi_transfer *xfer;
1022 bool keep_cs = false;
1024 unsigned long long ms = 1;
1025 struct spi_statistics *statm = &ctlr->statistics;
1026 struct spi_statistics *stats = &msg->spi->statistics;
1028 spi_set_cs(msg->spi, true);
1030 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1031 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1033 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1034 trace_spi_transfer_start(msg, xfer);
1036 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1037 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1039 if (xfer->tx_buf || xfer->rx_buf) {
1040 reinit_completion(&ctlr->xfer_completion);
1042 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1044 SPI_STATISTICS_INCREMENT_FIELD(statm,
1046 SPI_STATISTICS_INCREMENT_FIELD(stats,
1048 dev_err(&msg->spi->dev,
1049 "SPI transfer failed: %d\n", ret);
1055 ms = 8LL * 1000LL * xfer->len;
1056 do_div(ms, xfer->speed_hz);
1057 ms += ms + 200; /* some tolerance */
1062 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1063 msecs_to_jiffies(ms));
1067 SPI_STATISTICS_INCREMENT_FIELD(statm,
1069 SPI_STATISTICS_INCREMENT_FIELD(stats,
1071 dev_err(&msg->spi->dev,
1072 "SPI transfer timed out\n");
1073 msg->status = -ETIMEDOUT;
1077 dev_err(&msg->spi->dev,
1078 "Bufferless transfer has length %u\n",
1082 trace_spi_transfer_stop(msg, xfer);
1084 if (msg->status != -EINPROGRESS)
1087 if (xfer->delay_usecs) {
1088 u16 us = xfer->delay_usecs;
1093 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1096 if (xfer->cs_change) {
1097 if (list_is_last(&xfer->transfer_list,
1101 spi_set_cs(msg->spi, false);
1103 spi_set_cs(msg->spi, true);
1107 msg->actual_length += xfer->len;
1111 if (ret != 0 || !keep_cs)
1112 spi_set_cs(msg->spi, false);
1114 if (msg->status == -EINPROGRESS)
1117 if (msg->status && ctlr->handle_err)
1118 ctlr->handle_err(ctlr, msg);
1120 spi_finalize_current_message(ctlr);
1126 * spi_finalize_current_transfer - report completion of a transfer
1127 * @ctlr: the controller reporting completion
1129 * Called by SPI drivers using the core transfer_one_message()
1130 * implementation to notify it that the current interrupt driven
1131 * transfer has finished and the next one may be scheduled.
1133 void spi_finalize_current_transfer(struct spi_controller *ctlr)
1135 complete(&ctlr->xfer_completion);
1137 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1140 * __spi_pump_messages - function which processes spi message queue
1141 * @ctlr: controller to process queue for
1142 * @in_kthread: true if we are in the context of the message pump thread
1144 * This function checks if there is any spi message in the queue that
1145 * needs processing and if so call out to the driver to initialize hardware
1146 * and transfer each message.
1148 * Note that it is called both from the kthread itself and also from
1149 * inside spi_sync(); the queue extraction handling at the top of the
1150 * function should deal with this safely.
1152 static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1154 unsigned long flags;
1155 bool was_busy = false;
1159 spin_lock_irqsave(&ctlr->queue_lock, flags);
1161 /* Make sure we are not already running a message */
1162 if (ctlr->cur_msg) {
1163 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1167 /* If another context is idling the device then defer */
1169 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1170 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1174 /* Check if the queue is idle */
1175 if (list_empty(&ctlr->queue) || !ctlr->running) {
1177 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1181 /* Only do teardown in the thread */
1183 kthread_queue_work(&ctlr->kworker,
1184 &ctlr->pump_messages);
1185 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1190 ctlr->idling = true;
1191 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1193 kfree(ctlr->dummy_rx);
1194 ctlr->dummy_rx = NULL;
1195 kfree(ctlr->dummy_tx);
1196 ctlr->dummy_tx = NULL;
1197 if (ctlr->unprepare_transfer_hardware &&
1198 ctlr->unprepare_transfer_hardware(ctlr))
1200 "failed to unprepare transfer hardware\n");
1201 if (ctlr->auto_runtime_pm) {
1202 pm_runtime_mark_last_busy(ctlr->dev.parent);
1203 pm_runtime_put_autosuspend(ctlr->dev.parent);
1205 trace_spi_controller_idle(ctlr);
1207 spin_lock_irqsave(&ctlr->queue_lock, flags);
1208 ctlr->idling = false;
1209 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1213 /* Extract head of queue */
1215 list_first_entry(&ctlr->queue, struct spi_message, queue);
1217 list_del_init(&ctlr->cur_msg->queue);
1222 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1224 mutex_lock(&ctlr->io_mutex);
1226 if (!was_busy && ctlr->auto_runtime_pm) {
1227 ret = pm_runtime_get_sync(ctlr->dev.parent);
1229 pm_runtime_put_noidle(ctlr->dev.parent);
1230 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1232 mutex_unlock(&ctlr->io_mutex);
1238 trace_spi_controller_busy(ctlr);
1240 if (!was_busy && ctlr->prepare_transfer_hardware) {
1241 ret = ctlr->prepare_transfer_hardware(ctlr);
1244 "failed to prepare transfer hardware\n");
1246 if (ctlr->auto_runtime_pm)
1247 pm_runtime_put(ctlr->dev.parent);
1248 mutex_unlock(&ctlr->io_mutex);
1253 trace_spi_message_start(ctlr->cur_msg);
1255 if (ctlr->prepare_message) {
1256 ret = ctlr->prepare_message(ctlr, ctlr->cur_msg);
1258 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1260 ctlr->cur_msg->status = ret;
1261 spi_finalize_current_message(ctlr);
1264 ctlr->cur_msg_prepared = true;
1267 ret = spi_map_msg(ctlr, ctlr->cur_msg);
1269 ctlr->cur_msg->status = ret;
1270 spi_finalize_current_message(ctlr);
1274 ret = ctlr->transfer_one_message(ctlr, ctlr->cur_msg);
1277 "failed to transfer one message from queue\n");
1282 mutex_unlock(&ctlr->io_mutex);
1284 /* Prod the scheduler in case transfer_one() was busy waiting */
1290 * spi_pump_messages - kthread work function which processes spi message queue
1291 * @work: pointer to kthread work struct contained in the controller struct
1293 static void spi_pump_messages(struct kthread_work *work)
1295 struct spi_controller *ctlr =
1296 container_of(work, struct spi_controller, pump_messages);
1298 __spi_pump_messages(ctlr, true);
1301 static int spi_init_queue(struct spi_controller *ctlr)
1303 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1305 ctlr->running = false;
1308 kthread_init_worker(&ctlr->kworker);
1309 ctlr->kworker_task = kthread_run(kthread_worker_fn, &ctlr->kworker,
1310 "%s", dev_name(&ctlr->dev));
1311 if (IS_ERR(ctlr->kworker_task)) {
1312 dev_err(&ctlr->dev, "failed to create message pump task\n");
1313 return PTR_ERR(ctlr->kworker_task);
1315 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1318 * Controller config will indicate if this controller should run the
1319 * message pump with high (realtime) priority to reduce the transfer
1320 * latency on the bus by minimising the delay between a transfer
1321 * request and the scheduling of the message pump thread. Without this
1322 * setting the message pump thread will remain at default priority.
1325 dev_info(&ctlr->dev,
1326 "will run message pump with realtime priority\n");
1327 sched_setscheduler(ctlr->kworker_task, SCHED_FIFO, ¶m);
1334 * spi_get_next_queued_message() - called by driver to check for queued
1336 * @ctlr: the controller to check for queued messages
1338 * If there are more messages in the queue, the next message is returned from
1341 * Return: the next message in the queue, else NULL if the queue is empty.
1343 struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1345 struct spi_message *next;
1346 unsigned long flags;
1348 /* get a pointer to the next message, if any */
1349 spin_lock_irqsave(&ctlr->queue_lock, flags);
1350 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1352 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1356 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1359 * spi_finalize_current_message() - the current message is complete
1360 * @ctlr: the controller to return the message to
1362 * Called by the driver to notify the core that the message in the front of the
1363 * queue is complete and can be removed from the queue.
1365 void spi_finalize_current_message(struct spi_controller *ctlr)
1367 struct spi_message *mesg;
1368 unsigned long flags;
1371 spin_lock_irqsave(&ctlr->queue_lock, flags);
1372 mesg = ctlr->cur_msg;
1373 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1375 spi_unmap_msg(ctlr, mesg);
1377 /* In the prepare_messages callback the spi bus has the opportunity to
1378 * split a transfer to smaller chunks.
1379 * Release splited transfers here since spi_map_msg is done on the
1380 * splited transfers.
1382 spi_res_release(ctlr, mesg);
1384 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1385 ret = ctlr->unprepare_message(ctlr, mesg);
1387 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1392 spin_lock_irqsave(&ctlr->queue_lock, flags);
1393 ctlr->cur_msg = NULL;
1394 ctlr->cur_msg_prepared = false;
1395 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1396 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1398 trace_spi_message_done(mesg);
1402 mesg->complete(mesg->context);
1404 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1406 static int spi_start_queue(struct spi_controller *ctlr)
1408 unsigned long flags;
1410 spin_lock_irqsave(&ctlr->queue_lock, flags);
1412 if (ctlr->running || ctlr->busy) {
1413 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1417 ctlr->running = true;
1418 ctlr->cur_msg = NULL;
1419 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1421 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1426 static int spi_stop_queue(struct spi_controller *ctlr)
1428 unsigned long flags;
1429 unsigned limit = 500;
1432 spin_lock_irqsave(&ctlr->queue_lock, flags);
1435 * This is a bit lame, but is optimized for the common execution path.
1436 * A wait_queue on the ctlr->busy could be used, but then the common
1437 * execution path (pump_messages) would be required to call wake_up or
1438 * friends on every SPI message. Do this instead.
1440 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1441 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1442 usleep_range(10000, 11000);
1443 spin_lock_irqsave(&ctlr->queue_lock, flags);
1446 if (!list_empty(&ctlr->queue) || ctlr->busy)
1449 ctlr->running = false;
1451 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1454 dev_warn(&ctlr->dev, "could not stop message queue\n");
1460 static int spi_destroy_queue(struct spi_controller *ctlr)
1464 ret = spi_stop_queue(ctlr);
1467 * kthread_flush_worker will block until all work is done.
1468 * If the reason that stop_queue timed out is that the work will never
1469 * finish, then it does no good to call flush/stop thread, so
1473 dev_err(&ctlr->dev, "problem destroying queue\n");
1477 kthread_flush_worker(&ctlr->kworker);
1478 kthread_stop(ctlr->kworker_task);
1483 static int __spi_queued_transfer(struct spi_device *spi,
1484 struct spi_message *msg,
1487 struct spi_controller *ctlr = spi->controller;
1488 unsigned long flags;
1490 spin_lock_irqsave(&ctlr->queue_lock, flags);
1492 if (!ctlr->running) {
1493 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1496 msg->actual_length = 0;
1497 msg->status = -EINPROGRESS;
1499 list_add_tail(&msg->queue, &ctlr->queue);
1500 if (!ctlr->busy && need_pump)
1501 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1503 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1508 * spi_queued_transfer - transfer function for queued transfers
1509 * @spi: spi device which is requesting transfer
1510 * @msg: spi message which is to handled is queued to driver queue
1512 * Return: zero on success, else a negative error code.
1514 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1516 return __spi_queued_transfer(spi, msg, true);
1519 static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1523 ctlr->transfer = spi_queued_transfer;
1524 if (!ctlr->transfer_one_message)
1525 ctlr->transfer_one_message = spi_transfer_one_message;
1527 /* Initialize and start queue */
1528 ret = spi_init_queue(ctlr);
1530 dev_err(&ctlr->dev, "problem initializing queue\n");
1531 goto err_init_queue;
1533 ctlr->queued = true;
1534 ret = spi_start_queue(ctlr);
1536 dev_err(&ctlr->dev, "problem starting queue\n");
1537 goto err_start_queue;
1543 spi_destroy_queue(ctlr);
1549 * spi_flush_queue - Send all pending messages in the queue from the callers'
1551 * @ctlr: controller to process queue for
1553 * This should be used when one wants to ensure all pending messages have been
1554 * sent before doing something. Is used by the spi-mem code to make sure SPI
1555 * memory operations do not preempt regular SPI transfers that have been queued
1556 * before the spi-mem operation.
1558 void spi_flush_queue(struct spi_controller *ctlr)
1560 if (ctlr->transfer == spi_queued_transfer)
1561 __spi_pump_messages(ctlr, false);
1564 /*-------------------------------------------------------------------------*/
1566 #if defined(CONFIG_OF)
1567 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1568 struct device_node *nc)
1573 /* Mode (clock phase/polarity/etc.) */
1574 if (of_property_read_bool(nc, "spi-cpha"))
1575 spi->mode |= SPI_CPHA;
1576 if (of_property_read_bool(nc, "spi-cpol"))
1577 spi->mode |= SPI_CPOL;
1578 if (of_property_read_bool(nc, "spi-cs-high"))
1579 spi->mode |= SPI_CS_HIGH;
1580 if (of_property_read_bool(nc, "spi-3wire"))
1581 spi->mode |= SPI_3WIRE;
1582 if (of_property_read_bool(nc, "spi-lsb-first"))
1583 spi->mode |= SPI_LSB_FIRST;
1585 /* Device DUAL/QUAD mode */
1586 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1591 spi->mode |= SPI_TX_DUAL;
1594 spi->mode |= SPI_TX_QUAD;
1597 dev_warn(&ctlr->dev,
1598 "spi-tx-bus-width %d not supported\n",
1604 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1609 spi->mode |= SPI_RX_DUAL;
1612 spi->mode |= SPI_RX_QUAD;
1615 dev_warn(&ctlr->dev,
1616 "spi-rx-bus-width %d not supported\n",
1622 if (spi_controller_is_slave(ctlr)) {
1623 if (strcmp(nc->name, "slave")) {
1624 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
1631 /* Device address */
1632 rc = of_property_read_u32(nc, "reg", &value);
1634 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
1638 spi->chip_select = value;
1641 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1644 "%pOF has no valid 'spi-max-frequency' property (%d)\n", nc, rc);
1647 spi->max_speed_hz = value;
1652 static struct spi_device *
1653 of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
1655 struct spi_device *spi;
1658 /* Alloc an spi_device */
1659 spi = spi_alloc_device(ctlr);
1661 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
1666 /* Select device driver */
1667 rc = of_modalias_node(nc, spi->modalias,
1668 sizeof(spi->modalias));
1670 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
1674 rc = of_spi_parse_dt(ctlr, spi, nc);
1678 /* Store a pointer to the node in the device structure */
1680 spi->dev.of_node = nc;
1681 spi->dev.fwnode = of_fwnode_handle(nc);
1683 /* Register the new device */
1684 rc = spi_add_device(spi);
1686 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
1687 goto err_of_node_put;
1700 * of_register_spi_devices() - Register child devices onto the SPI bus
1701 * @ctlr: Pointer to spi_controller device
1703 * Registers an spi_device for each child node of controller node which
1704 * represents a valid SPI slave.
1706 static void of_register_spi_devices(struct spi_controller *ctlr)
1708 struct spi_device *spi;
1709 struct device_node *nc;
1711 if (!ctlr->dev.of_node)
1714 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
1715 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1717 spi = of_register_spi_device(ctlr, nc);
1719 dev_warn(&ctlr->dev,
1720 "Failed to create SPI device for %pOF\n", nc);
1721 of_node_clear_flag(nc, OF_POPULATED);
1726 static void of_register_spi_devices(struct spi_controller *ctlr) { }
1730 static void acpi_spi_parse_apple_properties(struct spi_device *spi)
1732 struct acpi_device *dev = ACPI_COMPANION(&spi->dev);
1733 const union acpi_object *obj;
1735 if (!x86_apple_machine)
1738 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
1739 && obj->buffer.length >= 4)
1740 spi->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
1742 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
1743 && obj->buffer.length == 8)
1744 spi->bits_per_word = *(u64 *)obj->buffer.pointer;
1746 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
1747 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
1748 spi->mode |= SPI_LSB_FIRST;
1750 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
1751 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
1752 spi->mode |= SPI_CPOL;
1754 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
1755 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
1756 spi->mode |= SPI_CPHA;
1759 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1761 struct spi_device *spi = data;
1762 struct spi_controller *ctlr = spi->controller;
1764 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1765 struct acpi_resource_spi_serialbus *sb;
1767 sb = &ares->data.spi_serial_bus;
1768 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1770 * ACPI DeviceSelection numbering is handled by the
1771 * host controller driver in Windows and can vary
1772 * from driver to driver. In Linux we always expect
1773 * 0 .. max - 1 so we need to ask the driver to
1774 * translate between the two schemes.
1776 if (ctlr->fw_translate_cs) {
1777 int cs = ctlr->fw_translate_cs(ctlr,
1778 sb->device_selection);
1781 spi->chip_select = cs;
1783 spi->chip_select = sb->device_selection;
1786 spi->max_speed_hz = sb->connection_speed;
1788 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1789 spi->mode |= SPI_CPHA;
1790 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1791 spi->mode |= SPI_CPOL;
1792 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1793 spi->mode |= SPI_CS_HIGH;
1795 } else if (spi->irq < 0) {
1798 if (acpi_dev_resource_interrupt(ares, 0, &r))
1802 /* Always tell the ACPI core to skip this resource */
1806 static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
1807 struct acpi_device *adev)
1809 struct list_head resource_list;
1810 struct spi_device *spi;
1813 if (acpi_bus_get_status(adev) || !adev->status.present ||
1814 acpi_device_enumerated(adev))
1817 spi = spi_alloc_device(ctlr);
1819 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
1820 dev_name(&adev->dev));
1821 return AE_NO_MEMORY;
1824 ACPI_COMPANION_SET(&spi->dev, adev);
1827 INIT_LIST_HEAD(&resource_list);
1828 ret = acpi_dev_get_resources(adev, &resource_list,
1829 acpi_spi_add_resource, spi);
1830 acpi_dev_free_resource_list(&resource_list);
1832 acpi_spi_parse_apple_properties(spi);
1834 if (ret < 0 || !spi->max_speed_hz) {
1839 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
1840 sizeof(spi->modalias));
1843 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1845 acpi_device_set_enumerated(adev);
1847 adev->power.flags.ignore_parent = true;
1848 if (spi_add_device(spi)) {
1849 adev->power.flags.ignore_parent = false;
1850 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
1851 dev_name(&adev->dev));
1858 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1859 void *data, void **return_value)
1861 struct spi_controller *ctlr = data;
1862 struct acpi_device *adev;
1864 if (acpi_bus_get_device(handle, &adev))
1867 return acpi_register_spi_device(ctlr, adev);
1870 static void acpi_register_spi_devices(struct spi_controller *ctlr)
1875 handle = ACPI_HANDLE(ctlr->dev.parent);
1879 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1880 acpi_spi_add_device, NULL, ctlr, NULL);
1881 if (ACPI_FAILURE(status))
1882 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
1885 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
1886 #endif /* CONFIG_ACPI */
1888 static void spi_controller_release(struct device *dev)
1890 struct spi_controller *ctlr;
1892 ctlr = container_of(dev, struct spi_controller, dev);
1896 static struct class spi_master_class = {
1897 .name = "spi_master",
1898 .owner = THIS_MODULE,
1899 .dev_release = spi_controller_release,
1900 .dev_groups = spi_master_groups,
1903 #ifdef CONFIG_SPI_SLAVE
1905 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
1907 * @spi: device used for the current transfer
1909 int spi_slave_abort(struct spi_device *spi)
1911 struct spi_controller *ctlr = spi->controller;
1913 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
1914 return ctlr->slave_abort(ctlr);
1918 EXPORT_SYMBOL_GPL(spi_slave_abort);
1920 static int match_true(struct device *dev, void *data)
1925 static ssize_t spi_slave_show(struct device *dev,
1926 struct device_attribute *attr, char *buf)
1928 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
1930 struct device *child;
1932 child = device_find_child(&ctlr->dev, NULL, match_true);
1933 return sprintf(buf, "%s\n",
1934 child ? to_spi_device(child)->modalias : NULL);
1937 static ssize_t spi_slave_store(struct device *dev,
1938 struct device_attribute *attr, const char *buf,
1941 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
1943 struct spi_device *spi;
1944 struct device *child;
1948 rc = sscanf(buf, "%31s", name);
1949 if (rc != 1 || !name[0])
1952 child = device_find_child(&ctlr->dev, NULL, match_true);
1954 /* Remove registered slave */
1955 device_unregister(child);
1959 if (strcmp(name, "(null)")) {
1960 /* Register new slave */
1961 spi = spi_alloc_device(ctlr);
1965 strlcpy(spi->modalias, name, sizeof(spi->modalias));
1967 rc = spi_add_device(spi);
1977 static DEVICE_ATTR(slave, 0644, spi_slave_show, spi_slave_store);
1979 static struct attribute *spi_slave_attrs[] = {
1980 &dev_attr_slave.attr,
1984 static const struct attribute_group spi_slave_group = {
1985 .attrs = spi_slave_attrs,
1988 static const struct attribute_group *spi_slave_groups[] = {
1989 &spi_controller_statistics_group,
1994 static struct class spi_slave_class = {
1995 .name = "spi_slave",
1996 .owner = THIS_MODULE,
1997 .dev_release = spi_controller_release,
1998 .dev_groups = spi_slave_groups,
2001 extern struct class spi_slave_class; /* dummy */
2005 * __spi_alloc_controller - allocate an SPI master or slave controller
2006 * @dev: the controller, possibly using the platform_bus
2007 * @size: how much zeroed driver-private data to allocate; the pointer to this
2008 * memory is in the driver_data field of the returned device,
2009 * accessible with spi_controller_get_devdata().
2010 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2011 * slave (true) controller
2012 * Context: can sleep
2014 * This call is used only by SPI controller drivers, which are the
2015 * only ones directly touching chip registers. It's how they allocate
2016 * an spi_controller structure, prior to calling spi_register_controller().
2018 * This must be called from context that can sleep.
2020 * The caller is responsible for assigning the bus number and initializing the
2021 * controller's methods before calling spi_register_controller(); and (after
2022 * errors adding the device) calling spi_controller_put() to prevent a memory
2025 * Return: the SPI controller structure on success, else NULL.
2027 struct spi_controller *__spi_alloc_controller(struct device *dev,
2028 unsigned int size, bool slave)
2030 struct spi_controller *ctlr;
2035 ctlr = kzalloc(size + sizeof(*ctlr), GFP_KERNEL);
2039 device_initialize(&ctlr->dev);
2041 ctlr->num_chipselect = 1;
2042 ctlr->slave = slave;
2043 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2044 ctlr->dev.class = &spi_slave_class;
2046 ctlr->dev.class = &spi_master_class;
2047 ctlr->dev.parent = dev;
2048 pm_suspend_ignore_children(&ctlr->dev, true);
2049 spi_controller_set_devdata(ctlr, &ctlr[1]);
2053 EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2055 static void devm_spi_release_controller(struct device *dev, void *ctlr)
2057 spi_controller_put(*(struct spi_controller **)ctlr);
2061 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
2062 * @dev: physical device of SPI controller
2063 * @size: how much zeroed driver-private data to allocate
2064 * @slave: whether to allocate an SPI master (false) or SPI slave (true)
2065 * Context: can sleep
2067 * Allocate an SPI controller and automatically release a reference on it
2068 * when @dev is unbound from its driver. Drivers are thus relieved from
2069 * having to call spi_controller_put().
2071 * The arguments to this function are identical to __spi_alloc_controller().
2073 * Return: the SPI controller structure on success, else NULL.
2075 struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
2079 struct spi_controller **ptr, *ctlr;
2081 ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),
2086 ctlr = __spi_alloc_controller(dev, size, slave);
2088 ctlr->devm_allocated = true;
2090 devres_add(dev, ptr);
2097 EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);
2100 static int of_spi_register_master(struct spi_controller *ctlr)
2103 struct device_node *np = ctlr->dev.of_node;
2108 nb = of_gpio_named_count(np, "cs-gpios");
2109 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2111 /* Return error only for an incorrectly formed cs-gpios property */
2112 if (nb == 0 || nb == -ENOENT)
2117 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2119 ctlr->cs_gpios = cs;
2121 if (!ctlr->cs_gpios)
2124 for (i = 0; i < ctlr->num_chipselect; i++)
2127 for (i = 0; i < nb; i++)
2128 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2133 static int of_spi_register_master(struct spi_controller *ctlr)
2139 static int spi_controller_check_ops(struct spi_controller *ctlr)
2142 * The controller may implement only the high-level SPI-memory like
2143 * operations if it does not support regular SPI transfers, and this is
2145 * If ->mem_ops is NULL, we request that at least one of the
2146 * ->transfer_xxx() method be implemented.
2148 if (ctlr->mem_ops) {
2149 if (!ctlr->mem_ops->exec_op)
2151 } else if (!ctlr->transfer && !ctlr->transfer_one &&
2152 !ctlr->transfer_one_message) {
2160 * spi_register_controller - register SPI master or slave controller
2161 * @ctlr: initialized master, originally from spi_alloc_master() or
2163 * Context: can sleep
2165 * SPI controllers connect to their drivers using some non-SPI bus,
2166 * such as the platform bus. The final stage of probe() in that code
2167 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2169 * SPI controllers use board specific (often SOC specific) bus numbers,
2170 * and board-specific addressing for SPI devices combines those numbers
2171 * with chip select numbers. Since SPI does not directly support dynamic
2172 * device identification, boards need configuration tables telling which
2173 * chip is at which address.
2175 * This must be called from context that can sleep. It returns zero on
2176 * success, else a negative error code (dropping the controller's refcount).
2177 * After a successful return, the caller is responsible for calling
2178 * spi_unregister_controller().
2180 * Return: zero on success, else a negative error code.
2182 int spi_register_controller(struct spi_controller *ctlr)
2184 struct device *dev = ctlr->dev.parent;
2185 struct boardinfo *bi;
2186 int status = -ENODEV;
2187 int id, first_dynamic;
2193 * Make sure all necessary hooks are implemented before registering
2194 * the SPI controller.
2196 status = spi_controller_check_ops(ctlr);
2200 if (!spi_controller_is_slave(ctlr)) {
2201 status = of_spi_register_master(ctlr);
2206 /* even if it's just one always-selected device, there must
2207 * be at least one chipselect
2209 if (ctlr->num_chipselect == 0)
2211 if (ctlr->bus_num >= 0) {
2212 /* devices with a fixed bus num must check-in with the num */
2213 mutex_lock(&board_lock);
2214 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2215 ctlr->bus_num + 1, GFP_KERNEL);
2216 mutex_unlock(&board_lock);
2217 if (WARN(id < 0, "couldn't get idr"))
2218 return id == -ENOSPC ? -EBUSY : id;
2220 } else if (ctlr->dev.of_node) {
2221 /* allocate dynamic bus number using Linux idr */
2222 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2225 mutex_lock(&board_lock);
2226 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2227 ctlr->bus_num + 1, GFP_KERNEL);
2228 mutex_unlock(&board_lock);
2229 if (WARN(id < 0, "couldn't get idr"))
2230 return id == -ENOSPC ? -EBUSY : id;
2233 if (ctlr->bus_num < 0) {
2234 first_dynamic = of_alias_get_highest_id("spi");
2235 if (first_dynamic < 0)
2240 mutex_lock(&board_lock);
2241 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2243 mutex_unlock(&board_lock);
2244 if (WARN(id < 0, "couldn't get idr"))
2248 INIT_LIST_HEAD(&ctlr->queue);
2249 spin_lock_init(&ctlr->queue_lock);
2250 spin_lock_init(&ctlr->bus_lock_spinlock);
2251 mutex_init(&ctlr->bus_lock_mutex);
2252 mutex_init(&ctlr->io_mutex);
2253 ctlr->bus_lock_flag = 0;
2254 init_completion(&ctlr->xfer_completion);
2255 if (!ctlr->max_dma_len)
2256 ctlr->max_dma_len = INT_MAX;
2258 /* register the device, then userspace will see it.
2259 * registration fails if the bus ID is in use.
2261 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2262 status = device_add(&ctlr->dev);
2265 mutex_lock(&board_lock);
2266 idr_remove(&spi_master_idr, ctlr->bus_num);
2267 mutex_unlock(&board_lock);
2270 dev_dbg(dev, "registered %s %s\n",
2271 spi_controller_is_slave(ctlr) ? "slave" : "master",
2272 dev_name(&ctlr->dev));
2275 * If we're using a queued driver, start the queue. Note that we don't
2276 * need the queueing logic if the driver is only supporting high-level
2277 * memory operations.
2279 if (ctlr->transfer) {
2280 dev_info(dev, "controller is unqueued, this is deprecated\n");
2281 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2282 status = spi_controller_initialize_queue(ctlr);
2284 device_del(&ctlr->dev);
2286 mutex_lock(&board_lock);
2287 idr_remove(&spi_master_idr, ctlr->bus_num);
2288 mutex_unlock(&board_lock);
2292 /* add statistics */
2293 spin_lock_init(&ctlr->statistics.lock);
2295 mutex_lock(&board_lock);
2296 list_add_tail(&ctlr->list, &spi_controller_list);
2297 list_for_each_entry(bi, &board_list, list)
2298 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2299 mutex_unlock(&board_lock);
2301 /* Register devices from the device tree and ACPI */
2302 of_register_spi_devices(ctlr);
2303 acpi_register_spi_devices(ctlr);
2307 EXPORT_SYMBOL_GPL(spi_register_controller);
2309 static void devm_spi_unregister(struct device *dev, void *res)
2311 spi_unregister_controller(*(struct spi_controller **)res);
2315 * devm_spi_register_controller - register managed SPI master or slave
2317 * @dev: device managing SPI controller
2318 * @ctlr: initialized controller, originally from spi_alloc_master() or
2320 * Context: can sleep
2322 * Register a SPI device as with spi_register_controller() which will
2323 * automatically be unregistered and freed.
2325 * Return: zero on success, else a negative error code.
2327 int devm_spi_register_controller(struct device *dev,
2328 struct spi_controller *ctlr)
2330 struct spi_controller **ptr;
2333 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2337 ret = spi_register_controller(ctlr);
2340 devres_add(dev, ptr);
2347 EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2349 static int __unregister(struct device *dev, void *null)
2351 spi_unregister_device(to_spi_device(dev));
2356 * spi_unregister_controller - unregister SPI master or slave controller
2357 * @ctlr: the controller being unregistered
2358 * Context: can sleep
2360 * This call is used only by SPI controller drivers, which are the
2361 * only ones directly touching chip registers.
2363 * This must be called from context that can sleep.
2365 * Note that this function also drops a reference to the controller.
2367 void spi_unregister_controller(struct spi_controller *ctlr)
2369 struct spi_controller *found;
2370 int id = ctlr->bus_num;
2372 /* Prevent addition of new devices, unregister existing ones */
2373 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2374 mutex_lock(&spi_add_lock);
2376 device_for_each_child(&ctlr->dev, NULL, __unregister);
2378 /* First make sure that this controller was ever added */
2379 mutex_lock(&board_lock);
2380 found = idr_find(&spi_master_idr, id);
2381 mutex_unlock(&board_lock);
2383 if (spi_destroy_queue(ctlr))
2384 dev_err(&ctlr->dev, "queue remove failed\n");
2386 mutex_lock(&board_lock);
2387 list_del(&ctlr->list);
2388 mutex_unlock(&board_lock);
2390 device_del(&ctlr->dev);
2392 /* Release the last reference on the controller if its driver
2393 * has not yet been converted to devm_spi_alloc_master/slave().
2395 if (!ctlr->devm_allocated)
2396 put_device(&ctlr->dev);
2399 mutex_lock(&board_lock);
2401 idr_remove(&spi_master_idr, id);
2402 mutex_unlock(&board_lock);
2404 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2405 mutex_unlock(&spi_add_lock);
2407 EXPORT_SYMBOL_GPL(spi_unregister_controller);
2409 int spi_controller_suspend(struct spi_controller *ctlr)
2413 /* Basically no-ops for non-queued controllers */
2417 ret = spi_stop_queue(ctlr);
2419 dev_err(&ctlr->dev, "queue stop failed\n");
2423 EXPORT_SYMBOL_GPL(spi_controller_suspend);
2425 int spi_controller_resume(struct spi_controller *ctlr)
2432 ret = spi_start_queue(ctlr);
2434 dev_err(&ctlr->dev, "queue restart failed\n");
2438 EXPORT_SYMBOL_GPL(spi_controller_resume);
2440 static int __spi_controller_match(struct device *dev, const void *data)
2442 struct spi_controller *ctlr;
2443 const u16 *bus_num = data;
2445 ctlr = container_of(dev, struct spi_controller, dev);
2446 return ctlr->bus_num == *bus_num;
2450 * spi_busnum_to_master - look up master associated with bus_num
2451 * @bus_num: the master's bus number
2452 * Context: can sleep
2454 * This call may be used with devices that are registered after
2455 * arch init time. It returns a refcounted pointer to the relevant
2456 * spi_controller (which the caller must release), or NULL if there is
2457 * no such master registered.
2459 * Return: the SPI master structure on success, else NULL.
2461 struct spi_controller *spi_busnum_to_master(u16 bus_num)
2464 struct spi_controller *ctlr = NULL;
2466 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2467 __spi_controller_match);
2469 ctlr = container_of(dev, struct spi_controller, dev);
2470 /* reference got in class_find_device */
2473 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2475 /*-------------------------------------------------------------------------*/
2477 /* Core methods for SPI resource management */
2480 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2481 * during the processing of a spi_message while using
2483 * @spi: the spi device for which we allocate memory
2484 * @release: the release code to execute for this resource
2485 * @size: size to alloc and return
2486 * @gfp: GFP allocation flags
2488 * Return: the pointer to the allocated data
2490 * This may get enhanced in the future to allocate from a memory pool
2491 * of the @spi_device or @spi_controller to avoid repeated allocations.
2493 void *spi_res_alloc(struct spi_device *spi,
2494 spi_res_release_t release,
2495 size_t size, gfp_t gfp)
2497 struct spi_res *sres;
2499 sres = kzalloc(sizeof(*sres) + size, gfp);
2503 INIT_LIST_HEAD(&sres->entry);
2504 sres->release = release;
2508 EXPORT_SYMBOL_GPL(spi_res_alloc);
2511 * spi_res_free - free an spi resource
2512 * @res: pointer to the custom data of a resource
2515 void spi_res_free(void *res)
2517 struct spi_res *sres = container_of(res, struct spi_res, data);
2522 WARN_ON(!list_empty(&sres->entry));
2525 EXPORT_SYMBOL_GPL(spi_res_free);
2528 * spi_res_add - add a spi_res to the spi_message
2529 * @message: the spi message
2530 * @res: the spi_resource
2532 void spi_res_add(struct spi_message *message, void *res)
2534 struct spi_res *sres = container_of(res, struct spi_res, data);
2536 WARN_ON(!list_empty(&sres->entry));
2537 list_add_tail(&sres->entry, &message->resources);
2539 EXPORT_SYMBOL_GPL(spi_res_add);
2542 * spi_res_release - release all spi resources for this message
2543 * @ctlr: the @spi_controller
2544 * @message: the @spi_message
2546 void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
2548 struct spi_res *res;
2550 while (!list_empty(&message->resources)) {
2551 res = list_last_entry(&message->resources,
2552 struct spi_res, entry);
2555 res->release(ctlr, message, res->data);
2557 list_del(&res->entry);
2562 EXPORT_SYMBOL_GPL(spi_res_release);
2564 /*-------------------------------------------------------------------------*/
2566 /* Core methods for spi_message alterations */
2568 static void __spi_replace_transfers_release(struct spi_controller *ctlr,
2569 struct spi_message *msg,
2572 struct spi_replaced_transfers *rxfer = res;
2575 /* call extra callback if requested */
2577 rxfer->release(ctlr, msg, res);
2579 /* insert replaced transfers back into the message */
2580 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2582 /* remove the formerly inserted entries */
2583 for (i = 0; i < rxfer->inserted; i++)
2584 list_del(&rxfer->inserted_transfers[i].transfer_list);
2588 * spi_replace_transfers - replace transfers with several transfers
2589 * and register change with spi_message.resources
2590 * @msg: the spi_message we work upon
2591 * @xfer_first: the first spi_transfer we want to replace
2592 * @remove: number of transfers to remove
2593 * @insert: the number of transfers we want to insert instead
2594 * @release: extra release code necessary in some circumstances
2595 * @extradatasize: extra data to allocate (with alignment guarantees
2596 * of struct @spi_transfer)
2599 * Returns: pointer to @spi_replaced_transfers,
2600 * PTR_ERR(...) in case of errors.
2602 struct spi_replaced_transfers *spi_replace_transfers(
2603 struct spi_message *msg,
2604 struct spi_transfer *xfer_first,
2607 spi_replaced_release_t release,
2608 size_t extradatasize,
2611 struct spi_replaced_transfers *rxfer;
2612 struct spi_transfer *xfer;
2615 /* allocate the structure using spi_res */
2616 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2617 insert * sizeof(struct spi_transfer)
2618 + sizeof(struct spi_replaced_transfers)
2622 return ERR_PTR(-ENOMEM);
2624 /* the release code to invoke before running the generic release */
2625 rxfer->release = release;
2627 /* assign extradata */
2630 &rxfer->inserted_transfers[insert];
2632 /* init the replaced_transfers list */
2633 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2635 /* assign the list_entry after which we should reinsert
2636 * the @replaced_transfers - it may be spi_message.messages!
2638 rxfer->replaced_after = xfer_first->transfer_list.prev;
2640 /* remove the requested number of transfers */
2641 for (i = 0; i < remove; i++) {
2642 /* if the entry after replaced_after it is msg->transfers
2643 * then we have been requested to remove more transfers
2644 * than are in the list
2646 if (rxfer->replaced_after->next == &msg->transfers) {
2647 dev_err(&msg->spi->dev,
2648 "requested to remove more spi_transfers than are available\n");
2649 /* insert replaced transfers back into the message */
2650 list_splice(&rxfer->replaced_transfers,
2651 rxfer->replaced_after);
2653 /* free the spi_replace_transfer structure */
2654 spi_res_free(rxfer);
2656 /* and return with an error */
2657 return ERR_PTR(-EINVAL);
2660 /* remove the entry after replaced_after from list of
2661 * transfers and add it to list of replaced_transfers
2663 list_move_tail(rxfer->replaced_after->next,
2664 &rxfer->replaced_transfers);
2667 /* create copy of the given xfer with identical settings
2668 * based on the first transfer to get removed
2670 for (i = 0; i < insert; i++) {
2671 /* we need to run in reverse order */
2672 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2674 /* copy all spi_transfer data */
2675 memcpy(xfer, xfer_first, sizeof(*xfer));
2678 list_add(&xfer->transfer_list, rxfer->replaced_after);
2680 /* clear cs_change and delay_usecs for all but the last */
2682 xfer->cs_change = false;
2683 xfer->delay_usecs = 0;
2687 /* set up inserted */
2688 rxfer->inserted = insert;
2690 /* and register it with spi_res/spi_message */
2691 spi_res_add(msg, rxfer);
2695 EXPORT_SYMBOL_GPL(spi_replace_transfers);
2697 static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
2698 struct spi_message *msg,
2699 struct spi_transfer **xferp,
2703 struct spi_transfer *xfer = *xferp, *xfers;
2704 struct spi_replaced_transfers *srt;
2708 /* warn once about this fact that we are splitting a transfer */
2709 dev_warn_once(&msg->spi->dev,
2710 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2711 xfer->len, maxsize);
2713 /* calculate how many we have to replace */
2714 count = DIV_ROUND_UP(xfer->len, maxsize);
2716 /* create replacement */
2717 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
2719 return PTR_ERR(srt);
2720 xfers = srt->inserted_transfers;
2722 /* now handle each of those newly inserted spi_transfers
2723 * note that the replacements spi_transfers all are preset
2724 * to the same values as *xferp, so tx_buf, rx_buf and len
2725 * are all identical (as well as most others)
2726 * so we just have to fix up len and the pointers.
2728 * this also includes support for the depreciated
2729 * spi_message.is_dma_mapped interface
2732 /* the first transfer just needs the length modified, so we
2733 * run it outside the loop
2735 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
2737 /* all the others need rx_buf/tx_buf also set */
2738 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2739 /* update rx_buf, tx_buf and dma */
2740 if (xfers[i].rx_buf)
2741 xfers[i].rx_buf += offset;
2742 if (xfers[i].rx_dma)
2743 xfers[i].rx_dma += offset;
2744 if (xfers[i].tx_buf)
2745 xfers[i].tx_buf += offset;
2746 if (xfers[i].tx_dma)
2747 xfers[i].tx_dma += offset;
2750 xfers[i].len = min(maxsize, xfers[i].len - offset);
2753 /* we set up xferp to the last entry we have inserted,
2754 * so that we skip those already split transfers
2756 *xferp = &xfers[count - 1];
2758 /* increment statistics counters */
2759 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
2760 transfers_split_maxsize);
2761 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2762 transfers_split_maxsize);
2768 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2769 * when an individual transfer exceeds a
2771 * @ctlr: the @spi_controller for this transfer
2772 * @msg: the @spi_message to transform
2773 * @maxsize: the maximum when to apply this
2774 * @gfp: GFP allocation flags
2776 * Return: status of transformation
2778 int spi_split_transfers_maxsize(struct spi_controller *ctlr,
2779 struct spi_message *msg,
2783 struct spi_transfer *xfer;
2786 /* iterate over the transfer_list,
2787 * but note that xfer is advanced to the last transfer inserted
2788 * to avoid checking sizes again unnecessarily (also xfer does
2789 * potentiall belong to a different list by the time the
2790 * replacement has happened
2792 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2793 if (xfer->len > maxsize) {
2794 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
2803 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2805 /*-------------------------------------------------------------------------*/
2807 /* Core methods for SPI controller protocol drivers. Some of the
2808 * other core methods are currently defined as inline functions.
2811 static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
2814 if (ctlr->bits_per_word_mask) {
2815 /* Only 32 bits fit in the mask */
2816 if (bits_per_word > 32)
2818 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
2826 * spi_setup - setup SPI mode and clock rate
2827 * @spi: the device whose settings are being modified
2828 * Context: can sleep, and no requests are queued to the device
2830 * SPI protocol drivers may need to update the transfer mode if the
2831 * device doesn't work with its default. They may likewise need
2832 * to update clock rates or word sizes from initial values. This function
2833 * changes those settings, and must be called from a context that can sleep.
2834 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2835 * effect the next time the device is selected and data is transferred to
2836 * or from it. When this function returns, the spi device is deselected.
2838 * Note that this call will fail if the protocol driver specifies an option
2839 * that the underlying controller or its driver does not support. For
2840 * example, not all hardware supports wire transfers using nine bit words,
2841 * LSB-first wire encoding, or active-high chipselects.
2843 * Return: zero on success, else a negative error code.
2845 int spi_setup(struct spi_device *spi)
2847 unsigned bad_bits, ugly_bits;
2850 /* check mode to prevent that DUAL and QUAD set at the same time
2852 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2853 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2855 "setup: can not select dual and quad at the same time\n");
2858 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2860 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2861 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2863 /* help drivers fail *cleanly* when they need options
2864 * that aren't supported with their current controller
2866 bad_bits = spi->mode & ~spi->controller->mode_bits;
2867 ugly_bits = bad_bits &
2868 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2871 "setup: ignoring unsupported mode bits %x\n",
2873 spi->mode &= ~ugly_bits;
2874 bad_bits &= ~ugly_bits;
2877 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
2882 if (!spi->bits_per_word)
2883 spi->bits_per_word = 8;
2885 status = __spi_validate_bits_per_word(spi->controller,
2886 spi->bits_per_word);
2890 if (!spi->max_speed_hz)
2891 spi->max_speed_hz = spi->controller->max_speed_hz;
2893 if (spi->controller->setup)
2894 status = spi->controller->setup(spi);
2896 spi_set_cs(spi, false);
2898 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2899 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2900 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2901 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2902 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2903 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2904 spi->bits_per_word, spi->max_speed_hz,
2909 EXPORT_SYMBOL_GPL(spi_setup);
2911 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
2913 struct spi_controller *ctlr = spi->controller;
2914 struct spi_transfer *xfer;
2917 if (list_empty(&message->transfers))
2920 /* Half-duplex links include original MicroWire, and ones with
2921 * only one data pin like SPI_3WIRE (switches direction) or where
2922 * either MOSI or MISO is missing. They can also be caused by
2923 * software limitations.
2925 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
2926 (spi->mode & SPI_3WIRE)) {
2927 unsigned flags = ctlr->flags;
2929 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2930 if (xfer->rx_buf && xfer->tx_buf)
2932 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
2934 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
2940 * Set transfer bits_per_word and max speed as spi device default if
2941 * it is not set for this transfer.
2942 * Set transfer tx_nbits and rx_nbits as single transfer default
2943 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2945 message->frame_length = 0;
2946 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2947 message->frame_length += xfer->len;
2948 if (!xfer->bits_per_word)
2949 xfer->bits_per_word = spi->bits_per_word;
2951 if (!xfer->speed_hz)
2952 xfer->speed_hz = spi->max_speed_hz;
2953 if (!xfer->speed_hz)
2954 xfer->speed_hz = ctlr->max_speed_hz;
2956 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
2957 xfer->speed_hz = ctlr->max_speed_hz;
2959 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
2963 * SPI transfer length should be multiple of SPI word size
2964 * where SPI word size should be power-of-two multiple
2966 if (xfer->bits_per_word <= 8)
2968 else if (xfer->bits_per_word <= 16)
2973 /* No partial transfers accepted */
2974 if (xfer->len % w_size)
2977 if (xfer->speed_hz && ctlr->min_speed_hz &&
2978 xfer->speed_hz < ctlr->min_speed_hz)
2981 if (xfer->tx_buf && !xfer->tx_nbits)
2982 xfer->tx_nbits = SPI_NBITS_SINGLE;
2983 if (xfer->rx_buf && !xfer->rx_nbits)
2984 xfer->rx_nbits = SPI_NBITS_SINGLE;
2985 /* check transfer tx/rx_nbits:
2986 * 1. check the value matches one of single, dual and quad
2987 * 2. check tx/rx_nbits match the mode in spi_device
2990 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2991 xfer->tx_nbits != SPI_NBITS_DUAL &&
2992 xfer->tx_nbits != SPI_NBITS_QUAD)
2994 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2995 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2997 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2998 !(spi->mode & SPI_TX_QUAD))
3001 /* check transfer rx_nbits */
3003 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3004 xfer->rx_nbits != SPI_NBITS_DUAL &&
3005 xfer->rx_nbits != SPI_NBITS_QUAD)
3007 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3008 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3010 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3011 !(spi->mode & SPI_RX_QUAD))
3016 message->status = -EINPROGRESS;
3021 static int __spi_async(struct spi_device *spi, struct spi_message *message)
3023 struct spi_controller *ctlr = spi->controller;
3026 * Some controllers do not support doing regular SPI transfers. Return
3027 * ENOTSUPP when this is the case.
3029 if (!ctlr->transfer)
3034 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
3035 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3037 trace_spi_message_submit(message);
3039 return ctlr->transfer(spi, message);
3043 * spi_async - asynchronous SPI transfer
3044 * @spi: device with which data will be exchanged
3045 * @message: describes the data transfers, including completion callback
3046 * Context: any (irqs may be blocked, etc)
3048 * This call may be used in_irq and other contexts which can't sleep,
3049 * as well as from task contexts which can sleep.
3051 * The completion callback is invoked in a context which can't sleep.
3052 * Before that invocation, the value of message->status is undefined.
3053 * When the callback is issued, message->status holds either zero (to
3054 * indicate complete success) or a negative error code. After that
3055 * callback returns, the driver which issued the transfer request may
3056 * deallocate the associated memory; it's no longer in use by any SPI
3057 * core or controller driver code.
3059 * Note that although all messages to a spi_device are handled in
3060 * FIFO order, messages may go to different devices in other orders.
3061 * Some device might be higher priority, or have various "hard" access
3062 * time requirements, for example.
3064 * On detection of any fault during the transfer, processing of
3065 * the entire message is aborted, and the device is deselected.
3066 * Until returning from the associated message completion callback,
3067 * no other spi_message queued to that device will be processed.
3068 * (This rule applies equally to all the synchronous transfer calls,
3069 * which are wrappers around this core asynchronous primitive.)
3071 * Return: zero on success, else a negative error code.
3073 int spi_async(struct spi_device *spi, struct spi_message *message)
3075 struct spi_controller *ctlr = spi->controller;
3077 unsigned long flags;
3079 ret = __spi_validate(spi, message);
3083 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3085 if (ctlr->bus_lock_flag)
3088 ret = __spi_async(spi, message);
3090 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3094 EXPORT_SYMBOL_GPL(spi_async);
3097 * spi_async_locked - version of spi_async with exclusive bus usage
3098 * @spi: device with which data will be exchanged
3099 * @message: describes the data transfers, including completion callback
3100 * Context: any (irqs may be blocked, etc)
3102 * This call may be used in_irq and other contexts which can't sleep,
3103 * as well as from task contexts which can sleep.
3105 * The completion callback is invoked in a context which can't sleep.
3106 * Before that invocation, the value of message->status is undefined.
3107 * When the callback is issued, message->status holds either zero (to
3108 * indicate complete success) or a negative error code. After that
3109 * callback returns, the driver which issued the transfer request may
3110 * deallocate the associated memory; it's no longer in use by any SPI
3111 * core or controller driver code.
3113 * Note that although all messages to a spi_device are handled in
3114 * FIFO order, messages may go to different devices in other orders.
3115 * Some device might be higher priority, or have various "hard" access
3116 * time requirements, for example.
3118 * On detection of any fault during the transfer, processing of
3119 * the entire message is aborted, and the device is deselected.
3120 * Until returning from the associated message completion callback,
3121 * no other spi_message queued to that device will be processed.
3122 * (This rule applies equally to all the synchronous transfer calls,
3123 * which are wrappers around this core asynchronous primitive.)
3125 * Return: zero on success, else a negative error code.
3127 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3129 struct spi_controller *ctlr = spi->controller;
3131 unsigned long flags;
3133 ret = __spi_validate(spi, message);
3137 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3139 ret = __spi_async(spi, message);
3141 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3146 EXPORT_SYMBOL_GPL(spi_async_locked);
3148 /*-------------------------------------------------------------------------*/
3150 /* Utility methods for SPI protocol drivers, layered on
3151 * top of the core. Some other utility methods are defined as
3155 static void spi_complete(void *arg)
3160 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3162 DECLARE_COMPLETION_ONSTACK(done);
3164 struct spi_controller *ctlr = spi->controller;
3165 unsigned long flags;
3167 status = __spi_validate(spi, message);
3171 message->complete = spi_complete;
3172 message->context = &done;
3175 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3176 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3178 /* If we're not using the legacy transfer method then we will
3179 * try to transfer in the calling context so special case.
3180 * This code would be less tricky if we could remove the
3181 * support for driver implemented message queues.
3183 if (ctlr->transfer == spi_queued_transfer) {
3184 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3186 trace_spi_message_submit(message);
3188 status = __spi_queued_transfer(spi, message, false);
3190 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3192 status = spi_async_locked(spi, message);
3196 /* Push out the messages in the calling context if we
3199 if (ctlr->transfer == spi_queued_transfer) {
3200 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3201 spi_sync_immediate);
3202 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3203 spi_sync_immediate);
3204 __spi_pump_messages(ctlr, false);
3207 wait_for_completion(&done);
3208 status = message->status;
3210 message->context = NULL;
3215 * spi_sync - blocking/synchronous SPI data transfers
3216 * @spi: device with which data will be exchanged
3217 * @message: describes the data transfers
3218 * Context: can sleep
3220 * This call may only be used from a context that may sleep. The sleep
3221 * is non-interruptible, and has no timeout. Low-overhead controller
3222 * drivers may DMA directly into and out of the message buffers.
3224 * Note that the SPI device's chip select is active during the message,
3225 * and then is normally disabled between messages. Drivers for some
3226 * frequently-used devices may want to minimize costs of selecting a chip,
3227 * by leaving it selected in anticipation that the next message will go
3228 * to the same chip. (That may increase power usage.)
3230 * Also, the caller is guaranteeing that the memory associated with the
3231 * message will not be freed before this call returns.
3233 * Return: zero on success, else a negative error code.
3235 int spi_sync(struct spi_device *spi, struct spi_message *message)
3239 mutex_lock(&spi->controller->bus_lock_mutex);
3240 ret = __spi_sync(spi, message);
3241 mutex_unlock(&spi->controller->bus_lock_mutex);
3245 EXPORT_SYMBOL_GPL(spi_sync);
3248 * spi_sync_locked - version of spi_sync with exclusive bus usage
3249 * @spi: device with which data will be exchanged
3250 * @message: describes the data transfers
3251 * Context: can sleep
3253 * This call may only be used from a context that may sleep. The sleep
3254 * is non-interruptible, and has no timeout. Low-overhead controller
3255 * drivers may DMA directly into and out of the message buffers.
3257 * This call should be used by drivers that require exclusive access to the
3258 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3259 * be released by a spi_bus_unlock call when the exclusive access is over.
3261 * Return: zero on success, else a negative error code.
3263 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3265 return __spi_sync(spi, message);
3267 EXPORT_SYMBOL_GPL(spi_sync_locked);
3270 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3271 * @ctlr: SPI bus master that should be locked for exclusive bus access
3272 * Context: can sleep
3274 * This call may only be used from a context that may sleep. The sleep
3275 * is non-interruptible, and has no timeout.
3277 * This call should be used by drivers that require exclusive access to the
3278 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3279 * exclusive access is over. Data transfer must be done by spi_sync_locked
3280 * and spi_async_locked calls when the SPI bus lock is held.
3282 * Return: always zero.
3284 int spi_bus_lock(struct spi_controller *ctlr)
3286 unsigned long flags;
3288 mutex_lock(&ctlr->bus_lock_mutex);
3290 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3291 ctlr->bus_lock_flag = 1;
3292 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3294 /* mutex remains locked until spi_bus_unlock is called */
3298 EXPORT_SYMBOL_GPL(spi_bus_lock);
3301 * spi_bus_unlock - release the lock for exclusive SPI bus usage
3302 * @ctlr: SPI bus master that was locked for exclusive bus access
3303 * Context: can sleep
3305 * This call may only be used from a context that may sleep. The sleep
3306 * is non-interruptible, and has no timeout.
3308 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3311 * Return: always zero.
3313 int spi_bus_unlock(struct spi_controller *ctlr)
3315 ctlr->bus_lock_flag = 0;
3317 mutex_unlock(&ctlr->bus_lock_mutex);
3321 EXPORT_SYMBOL_GPL(spi_bus_unlock);
3323 /* portable code must never pass more than 32 bytes */
3324 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3329 * spi_write_then_read - SPI synchronous write followed by read
3330 * @spi: device with which data will be exchanged
3331 * @txbuf: data to be written (need not be dma-safe)
3332 * @n_tx: size of txbuf, in bytes
3333 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3334 * @n_rx: size of rxbuf, in bytes
3335 * Context: can sleep
3337 * This performs a half duplex MicroWire style transaction with the
3338 * device, sending txbuf and then reading rxbuf. The return value
3339 * is zero for success, else a negative errno status code.
3340 * This call may only be used from a context that may sleep.
3342 * Parameters to this routine are always copied using a small buffer;
3343 * portable code should never use this for more than 32 bytes.
3344 * Performance-sensitive or bulk transfer code should instead use
3345 * spi_{async,sync}() calls with dma-safe buffers.
3347 * Return: zero on success, else a negative error code.
3349 int spi_write_then_read(struct spi_device *spi,
3350 const void *txbuf, unsigned n_tx,
3351 void *rxbuf, unsigned n_rx)
3353 static DEFINE_MUTEX(lock);
3356 struct spi_message message;
3357 struct spi_transfer x[2];
3360 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3361 * copying here, (as a pure convenience thing), but we can
3362 * keep heap costs out of the hot path unless someone else is
3363 * using the pre-allocated buffer or the transfer is too large.
3365 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
3366 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3367 GFP_KERNEL | GFP_DMA);
3374 spi_message_init(&message);
3375 memset(x, 0, sizeof(x));
3378 spi_message_add_tail(&x[0], &message);
3382 spi_message_add_tail(&x[1], &message);
3385 memcpy(local_buf, txbuf, n_tx);
3386 x[0].tx_buf = local_buf;
3387 x[1].rx_buf = local_buf + n_tx;
3390 status = spi_sync(spi, &message);
3392 memcpy(rxbuf, x[1].rx_buf, n_rx);
3394 if (x[0].tx_buf == buf)
3395 mutex_unlock(&lock);
3401 EXPORT_SYMBOL_GPL(spi_write_then_read);
3403 /*-------------------------------------------------------------------------*/
3405 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
3406 static int __spi_of_device_match(struct device *dev, void *data)
3408 return dev->of_node == data;
3411 /* must call put_device() when done with returned spi_device device */
3412 static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3414 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3415 __spi_of_device_match);
3416 return dev ? to_spi_device(dev) : NULL;
3419 static int __spi_of_controller_match(struct device *dev, const void *data)
3421 return dev->of_node == data;
3424 /* the spi controllers are not using spi_bus, so we find it with another way */
3425 static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
3429 dev = class_find_device(&spi_master_class, NULL, node,
3430 __spi_of_controller_match);
3431 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3432 dev = class_find_device(&spi_slave_class, NULL, node,
3433 __spi_of_controller_match);
3437 /* reference got in class_find_device */
3438 return container_of(dev, struct spi_controller, dev);
3441 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3444 struct of_reconfig_data *rd = arg;
3445 struct spi_controller *ctlr;
3446 struct spi_device *spi;
3448 switch (of_reconfig_get_state_change(action, arg)) {
3449 case OF_RECONFIG_CHANGE_ADD:
3450 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
3452 return NOTIFY_OK; /* not for us */
3454 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3455 put_device(&ctlr->dev);
3459 spi = of_register_spi_device(ctlr, rd->dn);
3460 put_device(&ctlr->dev);
3463 pr_err("%s: failed to create for '%pOF'\n",
3465 of_node_clear_flag(rd->dn, OF_POPULATED);
3466 return notifier_from_errno(PTR_ERR(spi));
3470 case OF_RECONFIG_CHANGE_REMOVE:
3471 /* already depopulated? */
3472 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3475 /* find our device by node */
3476 spi = of_find_spi_device_by_node(rd->dn);
3478 return NOTIFY_OK; /* no? not meant for us */
3480 /* unregister takes one ref away */
3481 spi_unregister_device(spi);
3483 /* and put the reference of the find */
3484 put_device(&spi->dev);
3491 static struct notifier_block spi_of_notifier = {
3492 .notifier_call = of_spi_notify,
3494 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3495 extern struct notifier_block spi_of_notifier;
3496 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3498 #if IS_ENABLED(CONFIG_ACPI)
3499 static int spi_acpi_controller_match(struct device *dev, const void *data)
3501 return ACPI_COMPANION(dev->parent) == data;
3504 static int spi_acpi_device_match(struct device *dev, void *data)
3506 return ACPI_COMPANION(dev) == data;
3509 static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
3513 dev = class_find_device(&spi_master_class, NULL, adev,
3514 spi_acpi_controller_match);
3515 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3516 dev = class_find_device(&spi_slave_class, NULL, adev,
3517 spi_acpi_controller_match);
3521 return container_of(dev, struct spi_controller, dev);
3524 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3528 dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3530 return dev ? to_spi_device(dev) : NULL;
3533 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3536 struct acpi_device *adev = arg;
3537 struct spi_controller *ctlr;
3538 struct spi_device *spi;
3541 case ACPI_RECONFIG_DEVICE_ADD:
3542 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
3546 acpi_register_spi_device(ctlr, adev);
3547 put_device(&ctlr->dev);
3549 case ACPI_RECONFIG_DEVICE_REMOVE:
3550 if (!acpi_device_enumerated(adev))
3553 spi = acpi_spi_find_device_by_adev(adev);
3557 spi_unregister_device(spi);
3558 put_device(&spi->dev);
3565 static struct notifier_block spi_acpi_notifier = {
3566 .notifier_call = acpi_spi_notify,
3569 extern struct notifier_block spi_acpi_notifier;
3572 static int __init spi_init(void)
3576 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
3582 status = bus_register(&spi_bus_type);
3586 status = class_register(&spi_master_class);
3590 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
3591 status = class_register(&spi_slave_class);
3596 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
3597 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3598 if (IS_ENABLED(CONFIG_ACPI))
3599 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
3604 class_unregister(&spi_master_class);
3606 bus_unregister(&spi_bus_type);
3614 /* board_info is normally registered in arch_initcall(),
3615 * but even essential drivers wait till later
3617 * REVISIT only boardinfo really needs static linking. the rest (device and
3618 * driver registration) _could_ be dynamically linked (modular) ... costs
3619 * include needing to have boardinfo data structures be much more public.
3621 postcore_initcall(spi_init);