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/of_gpio.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/pm_domain.h>
34 #include <linux/export.h>
35 #include <linux/sched/rt.h>
36 #include <linux/delay.h>
37 #include <linux/kthread.h>
38 #include <linux/ioport.h>
39 #include <linux/acpi.h>
40 #include <linux/highmem.h>
42 #define CREATE_TRACE_POINTS
43 #include <trace/events/spi.h>
45 static void spidev_release(struct device *dev)
47 struct spi_device *spi = to_spi_device(dev);
49 /* spi masters may cleanup for released devices */
50 if (spi->master->cleanup)
51 spi->master->cleanup(spi);
53 spi_master_put(spi->master);
58 modalias_show(struct device *dev, struct device_attribute *a, char *buf)
60 const struct spi_device *spi = to_spi_device(dev);
63 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
67 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
69 static DEVICE_ATTR_RO(modalias);
71 #define SPI_STATISTICS_ATTRS(field, file) \
72 static ssize_t spi_master_##field##_show(struct device *dev, \
73 struct device_attribute *attr, \
76 struct spi_master *master = container_of(dev, \
77 struct spi_master, dev); \
78 return spi_statistics_##field##_show(&master->statistics, buf); \
80 static struct device_attribute dev_attr_spi_master_##field = { \
81 .attr = { .name = file, .mode = S_IRUGO }, \
82 .show = spi_master_##field##_show, \
84 static ssize_t spi_device_##field##_show(struct device *dev, \
85 struct device_attribute *attr, \
88 struct spi_device *spi = to_spi_device(dev); \
89 return spi_statistics_##field##_show(&spi->statistics, buf); \
91 static struct device_attribute dev_attr_spi_device_##field = { \
92 .attr = { .name = file, .mode = S_IRUGO }, \
93 .show = spi_device_##field##_show, \
96 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
97 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
100 unsigned long flags; \
102 spin_lock_irqsave(&stat->lock, flags); \
103 len = sprintf(buf, format_string, stat->field); \
104 spin_unlock_irqrestore(&stat->lock, flags); \
107 SPI_STATISTICS_ATTRS(name, file)
109 #define SPI_STATISTICS_SHOW(field, format_string) \
110 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
111 field, format_string)
113 SPI_STATISTICS_SHOW(messages, "%lu");
114 SPI_STATISTICS_SHOW(transfers, "%lu");
115 SPI_STATISTICS_SHOW(errors, "%lu");
116 SPI_STATISTICS_SHOW(timedout, "%lu");
118 SPI_STATISTICS_SHOW(spi_sync, "%lu");
119 SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
120 SPI_STATISTICS_SHOW(spi_async, "%lu");
122 SPI_STATISTICS_SHOW(bytes, "%llu");
123 SPI_STATISTICS_SHOW(bytes_rx, "%llu");
124 SPI_STATISTICS_SHOW(bytes_tx, "%llu");
126 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
127 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
128 "transfer_bytes_histo_" number, \
129 transfer_bytes_histo[index], "%lu")
130 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
131 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
132 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
133 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
134 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
135 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
136 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
137 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
138 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
139 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
140 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
141 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
142 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
143 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
144 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
145 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
146 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
148 SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
150 static struct attribute *spi_dev_attrs[] = {
151 &dev_attr_modalias.attr,
155 static const struct attribute_group spi_dev_group = {
156 .attrs = spi_dev_attrs,
159 static struct attribute *spi_device_statistics_attrs[] = {
160 &dev_attr_spi_device_messages.attr,
161 &dev_attr_spi_device_transfers.attr,
162 &dev_attr_spi_device_errors.attr,
163 &dev_attr_spi_device_timedout.attr,
164 &dev_attr_spi_device_spi_sync.attr,
165 &dev_attr_spi_device_spi_sync_immediate.attr,
166 &dev_attr_spi_device_spi_async.attr,
167 &dev_attr_spi_device_bytes.attr,
168 &dev_attr_spi_device_bytes_rx.attr,
169 &dev_attr_spi_device_bytes_tx.attr,
170 &dev_attr_spi_device_transfer_bytes_histo0.attr,
171 &dev_attr_spi_device_transfer_bytes_histo1.attr,
172 &dev_attr_spi_device_transfer_bytes_histo2.attr,
173 &dev_attr_spi_device_transfer_bytes_histo3.attr,
174 &dev_attr_spi_device_transfer_bytes_histo4.attr,
175 &dev_attr_spi_device_transfer_bytes_histo5.attr,
176 &dev_attr_spi_device_transfer_bytes_histo6.attr,
177 &dev_attr_spi_device_transfer_bytes_histo7.attr,
178 &dev_attr_spi_device_transfer_bytes_histo8.attr,
179 &dev_attr_spi_device_transfer_bytes_histo9.attr,
180 &dev_attr_spi_device_transfer_bytes_histo10.attr,
181 &dev_attr_spi_device_transfer_bytes_histo11.attr,
182 &dev_attr_spi_device_transfer_bytes_histo12.attr,
183 &dev_attr_spi_device_transfer_bytes_histo13.attr,
184 &dev_attr_spi_device_transfer_bytes_histo14.attr,
185 &dev_attr_spi_device_transfer_bytes_histo15.attr,
186 &dev_attr_spi_device_transfer_bytes_histo16.attr,
187 &dev_attr_spi_device_transfers_split_maxsize.attr,
191 static const struct attribute_group spi_device_statistics_group = {
192 .name = "statistics",
193 .attrs = spi_device_statistics_attrs,
196 static const struct attribute_group *spi_dev_groups[] = {
198 &spi_device_statistics_group,
202 static struct attribute *spi_master_statistics_attrs[] = {
203 &dev_attr_spi_master_messages.attr,
204 &dev_attr_spi_master_transfers.attr,
205 &dev_attr_spi_master_errors.attr,
206 &dev_attr_spi_master_timedout.attr,
207 &dev_attr_spi_master_spi_sync.attr,
208 &dev_attr_spi_master_spi_sync_immediate.attr,
209 &dev_attr_spi_master_spi_async.attr,
210 &dev_attr_spi_master_bytes.attr,
211 &dev_attr_spi_master_bytes_rx.attr,
212 &dev_attr_spi_master_bytes_tx.attr,
213 &dev_attr_spi_master_transfer_bytes_histo0.attr,
214 &dev_attr_spi_master_transfer_bytes_histo1.attr,
215 &dev_attr_spi_master_transfer_bytes_histo2.attr,
216 &dev_attr_spi_master_transfer_bytes_histo3.attr,
217 &dev_attr_spi_master_transfer_bytes_histo4.attr,
218 &dev_attr_spi_master_transfer_bytes_histo5.attr,
219 &dev_attr_spi_master_transfer_bytes_histo6.attr,
220 &dev_attr_spi_master_transfer_bytes_histo7.attr,
221 &dev_attr_spi_master_transfer_bytes_histo8.attr,
222 &dev_attr_spi_master_transfer_bytes_histo9.attr,
223 &dev_attr_spi_master_transfer_bytes_histo10.attr,
224 &dev_attr_spi_master_transfer_bytes_histo11.attr,
225 &dev_attr_spi_master_transfer_bytes_histo12.attr,
226 &dev_attr_spi_master_transfer_bytes_histo13.attr,
227 &dev_attr_spi_master_transfer_bytes_histo14.attr,
228 &dev_attr_spi_master_transfer_bytes_histo15.attr,
229 &dev_attr_spi_master_transfer_bytes_histo16.attr,
230 &dev_attr_spi_master_transfers_split_maxsize.attr,
234 static const struct attribute_group spi_master_statistics_group = {
235 .name = "statistics",
236 .attrs = spi_master_statistics_attrs,
239 static const struct attribute_group *spi_master_groups[] = {
240 &spi_master_statistics_group,
244 void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
245 struct spi_transfer *xfer,
246 struct spi_master *master)
249 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
254 spin_lock_irqsave(&stats->lock, flags);
257 stats->transfer_bytes_histo[l2len]++;
259 stats->bytes += xfer->len;
260 if ((xfer->tx_buf) &&
261 (xfer->tx_buf != master->dummy_tx))
262 stats->bytes_tx += xfer->len;
263 if ((xfer->rx_buf) &&
264 (xfer->rx_buf != master->dummy_rx))
265 stats->bytes_rx += xfer->len;
267 spin_unlock_irqrestore(&stats->lock, flags);
269 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
271 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
272 * and the sysfs version makes coldplug work too.
275 static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
276 const struct spi_device *sdev)
278 while (id->name[0]) {
279 if (!strcmp(sdev->modalias, id->name))
286 const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
288 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
290 return spi_match_id(sdrv->id_table, sdev);
292 EXPORT_SYMBOL_GPL(spi_get_device_id);
294 static int spi_match_device(struct device *dev, struct device_driver *drv)
296 const struct spi_device *spi = to_spi_device(dev);
297 const struct spi_driver *sdrv = to_spi_driver(drv);
299 /* Attempt an OF style match */
300 if (of_driver_match_device(dev, drv))
304 if (acpi_driver_match_device(dev, drv))
308 return !!spi_match_id(sdrv->id_table, spi);
310 return strcmp(spi->modalias, drv->name) == 0;
313 static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
315 const struct spi_device *spi = to_spi_device(dev);
318 rc = acpi_device_uevent_modalias(dev, env);
322 add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
326 struct bus_type spi_bus_type = {
328 .dev_groups = spi_dev_groups,
329 .match = spi_match_device,
330 .uevent = spi_uevent,
332 EXPORT_SYMBOL_GPL(spi_bus_type);
335 static int spi_drv_probe(struct device *dev)
337 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
338 struct spi_device *spi = to_spi_device(dev);
341 ret = of_clk_set_defaults(dev->of_node, false);
346 spi->irq = of_irq_get(dev->of_node, 0);
347 if (spi->irq == -EPROBE_DEFER)
348 return -EPROBE_DEFER;
353 ret = dev_pm_domain_attach(dev, true);
354 if (ret != -EPROBE_DEFER) {
355 ret = sdrv->probe(spi);
357 dev_pm_domain_detach(dev, true);
363 static int spi_drv_remove(struct device *dev)
365 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
368 ret = sdrv->remove(to_spi_device(dev));
369 dev_pm_domain_detach(dev, true);
374 static void spi_drv_shutdown(struct device *dev)
376 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
378 sdrv->shutdown(to_spi_device(dev));
382 * __spi_register_driver - register a SPI driver
383 * @owner: owner module of the driver to register
384 * @sdrv: the driver to register
387 * Return: zero on success, else a negative error code.
389 int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
391 sdrv->driver.owner = owner;
392 sdrv->driver.bus = &spi_bus_type;
394 sdrv->driver.probe = spi_drv_probe;
396 sdrv->driver.remove = spi_drv_remove;
398 sdrv->driver.shutdown = spi_drv_shutdown;
399 return driver_register(&sdrv->driver);
401 EXPORT_SYMBOL_GPL(__spi_register_driver);
403 /*-------------------------------------------------------------------------*/
405 /* SPI devices should normally not be created by SPI device drivers; that
406 * would make them board-specific. Similarly with SPI master drivers.
407 * Device registration normally goes into like arch/.../mach.../board-YYY.c
408 * with other readonly (flashable) information about mainboard devices.
412 struct list_head list;
413 struct spi_board_info board_info;
416 static LIST_HEAD(board_list);
417 static LIST_HEAD(spi_master_list);
420 * Used to protect add/del opertion for board_info list and
421 * spi_master list, and their matching process
423 static DEFINE_MUTEX(board_lock);
426 * spi_alloc_device - Allocate a new SPI device
427 * @master: Controller to which device is connected
430 * Allows a driver to allocate and initialize a spi_device without
431 * registering it immediately. This allows a driver to directly
432 * fill the spi_device with device parameters before calling
433 * spi_add_device() on it.
435 * Caller is responsible to call spi_add_device() on the returned
436 * spi_device structure to add it to the SPI master. If the caller
437 * needs to discard the spi_device without adding it, then it should
438 * call spi_dev_put() on it.
440 * Return: a pointer to the new device, or NULL.
442 struct spi_device *spi_alloc_device(struct spi_master *master)
444 struct spi_device *spi;
446 if (!spi_master_get(master))
449 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
451 spi_master_put(master);
455 spi->master = master;
456 spi->dev.parent = &master->dev;
457 spi->dev.bus = &spi_bus_type;
458 spi->dev.release = spidev_release;
459 spi->cs_gpio = -ENOENT;
461 spin_lock_init(&spi->statistics.lock);
463 device_initialize(&spi->dev);
466 EXPORT_SYMBOL_GPL(spi_alloc_device);
468 static void spi_dev_set_name(struct spi_device *spi)
470 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
473 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
477 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
481 static int spi_dev_check(struct device *dev, void *data)
483 struct spi_device *spi = to_spi_device(dev);
484 struct spi_device *new_spi = data;
486 if (spi->master == new_spi->master &&
487 spi->chip_select == new_spi->chip_select)
493 * spi_add_device - Add spi_device allocated with spi_alloc_device
494 * @spi: spi_device to register
496 * Companion function to spi_alloc_device. Devices allocated with
497 * spi_alloc_device can be added onto the spi bus with this function.
499 * Return: 0 on success; negative errno on failure
501 int spi_add_device(struct spi_device *spi)
503 static DEFINE_MUTEX(spi_add_lock);
504 struct spi_master *master = spi->master;
505 struct device *dev = master->dev.parent;
508 /* Chipselects are numbered 0..max; validate. */
509 if (spi->chip_select >= master->num_chipselect) {
510 dev_err(dev, "cs%d >= max %d\n",
512 master->num_chipselect);
516 /* Set the bus ID string */
517 spi_dev_set_name(spi);
519 /* We need to make sure there's no other device with this
520 * chipselect **BEFORE** we call setup(), else we'll trash
521 * its configuration. Lock against concurrent add() calls.
523 mutex_lock(&spi_add_lock);
525 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
527 dev_err(dev, "chipselect %d already in use\n",
532 if (master->cs_gpios)
533 spi->cs_gpio = master->cs_gpios[spi->chip_select];
535 /* Drivers may modify this initial i/o setup, but will
536 * normally rely on the device being setup. Devices
537 * using SPI_CS_HIGH can't coexist well otherwise...
539 status = spi_setup(spi);
541 dev_err(dev, "can't setup %s, status %d\n",
542 dev_name(&spi->dev), status);
546 /* Device may be bound to an active driver when this returns */
547 status = device_add(&spi->dev);
549 dev_err(dev, "can't add %s, status %d\n",
550 dev_name(&spi->dev), status);
552 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
555 mutex_unlock(&spi_add_lock);
558 EXPORT_SYMBOL_GPL(spi_add_device);
561 * spi_new_device - instantiate one new SPI device
562 * @master: Controller to which device is connected
563 * @chip: Describes the SPI device
566 * On typical mainboards, this is purely internal; and it's not needed
567 * after board init creates the hard-wired devices. Some development
568 * platforms may not be able to use spi_register_board_info though, and
569 * this is exported so that for example a USB or parport based adapter
570 * driver could add devices (which it would learn about out-of-band).
572 * Return: the new device, or NULL.
574 struct spi_device *spi_new_device(struct spi_master *master,
575 struct spi_board_info *chip)
577 struct spi_device *proxy;
580 /* NOTE: caller did any chip->bus_num checks necessary.
582 * Also, unless we change the return value convention to use
583 * error-or-pointer (not NULL-or-pointer), troubleshootability
584 * suggests syslogged diagnostics are best here (ugh).
587 proxy = spi_alloc_device(master);
591 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
593 proxy->chip_select = chip->chip_select;
594 proxy->max_speed_hz = chip->max_speed_hz;
595 proxy->mode = chip->mode;
596 proxy->irq = chip->irq;
597 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
598 proxy->dev.platform_data = (void *) chip->platform_data;
599 proxy->controller_data = chip->controller_data;
600 proxy->controller_state = NULL;
602 status = spi_add_device(proxy);
610 EXPORT_SYMBOL_GPL(spi_new_device);
613 * spi_unregister_device - unregister a single SPI device
614 * @spi: spi_device to unregister
616 * Start making the passed SPI device vanish. Normally this would be handled
617 * by spi_unregister_master().
619 void spi_unregister_device(struct spi_device *spi)
624 if (spi->dev.of_node)
625 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
626 if (ACPI_COMPANION(&spi->dev))
627 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
628 device_unregister(&spi->dev);
630 EXPORT_SYMBOL_GPL(spi_unregister_device);
632 static void spi_match_master_to_boardinfo(struct spi_master *master,
633 struct spi_board_info *bi)
635 struct spi_device *dev;
637 if (master->bus_num != bi->bus_num)
640 dev = spi_new_device(master, bi);
642 dev_err(master->dev.parent, "can't create new device for %s\n",
647 * spi_register_board_info - register SPI devices for a given board
648 * @info: array of chip descriptors
649 * @n: how many descriptors are provided
652 * Board-specific early init code calls this (probably during arch_initcall)
653 * with segments of the SPI device table. Any device nodes are created later,
654 * after the relevant parent SPI controller (bus_num) is defined. We keep
655 * this table of devices forever, so that reloading a controller driver will
656 * not make Linux forget about these hard-wired devices.
658 * Other code can also call this, e.g. a particular add-on board might provide
659 * SPI devices through its expansion connector, so code initializing that board
660 * would naturally declare its SPI devices.
662 * The board info passed can safely be __initdata ... but be careful of
663 * any embedded pointers (platform_data, etc), they're copied as-is.
665 * Return: zero on success, else a negative error code.
667 int spi_register_board_info(struct spi_board_info const *info, unsigned n)
669 struct boardinfo *bi;
675 bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
679 for (i = 0; i < n; i++, bi++, info++) {
680 struct spi_master *master;
682 memcpy(&bi->board_info, info, sizeof(*info));
683 mutex_lock(&board_lock);
684 list_add_tail(&bi->list, &board_list);
685 list_for_each_entry(master, &spi_master_list, list)
686 spi_match_master_to_boardinfo(master, &bi->board_info);
687 mutex_unlock(&board_lock);
693 /*-------------------------------------------------------------------------*/
695 static void spi_set_cs(struct spi_device *spi, bool enable)
697 if (spi->mode & SPI_CS_HIGH)
700 if (gpio_is_valid(spi->cs_gpio)) {
701 gpio_set_value(spi->cs_gpio, !enable);
702 /* Some SPI masters need both GPIO CS & slave_select */
703 if ((spi->master->flags & SPI_MASTER_GPIO_SS) &&
705 spi->master->set_cs(spi, !enable);
706 } else if (spi->master->set_cs) {
707 spi->master->set_cs(spi, !enable);
711 #ifdef CONFIG_HAS_DMA
712 static int spi_map_buf(struct spi_master *master, struct device *dev,
713 struct sg_table *sgt, void *buf, size_t len,
714 enum dma_data_direction dir)
716 const bool vmalloced_buf = is_vmalloc_addr(buf);
717 unsigned int max_seg_size = dma_get_max_seg_size(dev);
718 #ifdef CONFIG_HIGHMEM
719 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
720 (unsigned long)buf < (PKMAP_BASE +
721 (LAST_PKMAP * PAGE_SIZE)));
723 const bool kmap_buf = false;
727 struct page *vm_page;
728 struct scatterlist *sg;
733 if (vmalloced_buf || kmap_buf) {
734 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
735 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
736 } else if (virt_addr_valid(buf)) {
737 desc_len = min_t(int, max_seg_size, master->max_dma_len);
738 sgs = DIV_ROUND_UP(len, desc_len);
743 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
748 for (i = 0; i < sgs; i++) {
750 if (vmalloced_buf || kmap_buf) {
752 len, desc_len - offset_in_page(buf));
754 vm_page = vmalloc_to_page(buf);
756 vm_page = kmap_to_page(buf);
761 sg_set_page(sg, vm_page,
762 min, offset_in_page(buf));
764 min = min_t(size_t, len, desc_len);
766 sg_set_buf(sg, sg_buf, min);
774 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
787 static void spi_unmap_buf(struct spi_master *master, struct device *dev,
788 struct sg_table *sgt, enum dma_data_direction dir)
790 if (sgt->orig_nents) {
791 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
796 static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
798 struct device *tx_dev, *rx_dev;
799 struct spi_transfer *xfer;
802 if (!master->can_dma)
806 tx_dev = master->dma_tx->device->dev;
808 tx_dev = &master->dev;
811 rx_dev = master->dma_rx->device->dev;
813 rx_dev = &master->dev;
815 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
816 if (!master->can_dma(master, msg->spi, xfer))
819 if (xfer->tx_buf != NULL) {
820 ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
821 (void *)xfer->tx_buf, xfer->len,
827 if (xfer->rx_buf != NULL) {
828 ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
829 xfer->rx_buf, xfer->len,
832 spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
839 master->cur_msg_mapped = true;
844 static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
846 struct spi_transfer *xfer;
847 struct device *tx_dev, *rx_dev;
849 if (!master->cur_msg_mapped || !master->can_dma)
853 tx_dev = master->dma_tx->device->dev;
855 tx_dev = &master->dev;
858 rx_dev = master->dma_rx->device->dev;
860 rx_dev = &master->dev;
862 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
863 if (!master->can_dma(master, msg->spi, xfer))
866 spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
867 spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
872 #else /* !CONFIG_HAS_DMA */
873 static inline int spi_map_buf(struct spi_master *master,
874 struct device *dev, struct sg_table *sgt,
875 void *buf, size_t len,
876 enum dma_data_direction dir)
881 static inline void spi_unmap_buf(struct spi_master *master,
882 struct device *dev, struct sg_table *sgt,
883 enum dma_data_direction dir)
887 static inline int __spi_map_msg(struct spi_master *master,
888 struct spi_message *msg)
893 static inline int __spi_unmap_msg(struct spi_master *master,
894 struct spi_message *msg)
898 #endif /* !CONFIG_HAS_DMA */
900 static inline int spi_unmap_msg(struct spi_master *master,
901 struct spi_message *msg)
903 struct spi_transfer *xfer;
905 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
907 * Restore the original value of tx_buf or rx_buf if they are
910 if (xfer->tx_buf == master->dummy_tx)
912 if (xfer->rx_buf == master->dummy_rx)
916 return __spi_unmap_msg(master, msg);
919 static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
921 struct spi_transfer *xfer;
923 unsigned int max_tx, max_rx;
925 if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
929 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
930 if ((master->flags & SPI_MASTER_MUST_TX) &&
932 max_tx = max(xfer->len, max_tx);
933 if ((master->flags & SPI_MASTER_MUST_RX) &&
935 max_rx = max(xfer->len, max_rx);
939 tmp = krealloc(master->dummy_tx, max_tx,
940 GFP_KERNEL | GFP_DMA);
943 master->dummy_tx = tmp;
944 memset(tmp, 0, max_tx);
948 tmp = krealloc(master->dummy_rx, max_rx,
949 GFP_KERNEL | GFP_DMA);
952 master->dummy_rx = tmp;
955 if (max_tx || max_rx) {
956 list_for_each_entry(xfer, &msg->transfers,
959 xfer->tx_buf = master->dummy_tx;
961 xfer->rx_buf = master->dummy_rx;
966 return __spi_map_msg(master, msg);
970 * spi_transfer_one_message - Default implementation of transfer_one_message()
972 * This is a standard implementation of transfer_one_message() for
973 * drivers which implement a transfer_one() operation. It provides
974 * standard handling of delays and chip select management.
976 static int spi_transfer_one_message(struct spi_master *master,
977 struct spi_message *msg)
979 struct spi_transfer *xfer;
980 bool keep_cs = false;
982 unsigned long long ms = 1;
983 struct spi_statistics *statm = &master->statistics;
984 struct spi_statistics *stats = &msg->spi->statistics;
986 spi_set_cs(msg->spi, true);
988 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
989 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
991 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
992 trace_spi_transfer_start(msg, xfer);
994 spi_statistics_add_transfer_stats(statm, xfer, master);
995 spi_statistics_add_transfer_stats(stats, xfer, master);
997 if (xfer->tx_buf || xfer->rx_buf) {
998 reinit_completion(&master->xfer_completion);
1000 ret = master->transfer_one(master, msg->spi, xfer);
1002 SPI_STATISTICS_INCREMENT_FIELD(statm,
1004 SPI_STATISTICS_INCREMENT_FIELD(stats,
1006 dev_err(&msg->spi->dev,
1007 "SPI transfer failed: %d\n", ret);
1013 ms = 8LL * 1000LL * xfer->len;
1014 do_div(ms, xfer->speed_hz);
1015 ms += ms + 100; /* some tolerance */
1020 ms = wait_for_completion_timeout(&master->xfer_completion,
1021 msecs_to_jiffies(ms));
1025 SPI_STATISTICS_INCREMENT_FIELD(statm,
1027 SPI_STATISTICS_INCREMENT_FIELD(stats,
1029 dev_err(&msg->spi->dev,
1030 "SPI transfer timed out\n");
1031 msg->status = -ETIMEDOUT;
1035 dev_err(&msg->spi->dev,
1036 "Bufferless transfer has length %u\n",
1040 trace_spi_transfer_stop(msg, xfer);
1042 if (msg->status != -EINPROGRESS)
1045 if (xfer->delay_usecs) {
1046 u16 us = xfer->delay_usecs;
1051 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1054 if (xfer->cs_change) {
1055 if (list_is_last(&xfer->transfer_list,
1059 spi_set_cs(msg->spi, false);
1061 spi_set_cs(msg->spi, true);
1065 msg->actual_length += xfer->len;
1069 if (ret != 0 || !keep_cs)
1070 spi_set_cs(msg->spi, false);
1072 if (msg->status == -EINPROGRESS)
1075 if (msg->status && master->handle_err)
1076 master->handle_err(master, msg);
1078 spi_res_release(master, msg);
1080 spi_finalize_current_message(master);
1086 * spi_finalize_current_transfer - report completion of a transfer
1087 * @master: the master reporting completion
1089 * Called by SPI drivers using the core transfer_one_message()
1090 * implementation to notify it that the current interrupt driven
1091 * transfer has finished and the next one may be scheduled.
1093 void spi_finalize_current_transfer(struct spi_master *master)
1095 complete(&master->xfer_completion);
1097 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1100 * __spi_pump_messages - function which processes spi message queue
1101 * @master: master to process queue for
1102 * @in_kthread: true if we are in the context of the message pump thread
1104 * This function checks if there is any spi message in the queue that
1105 * needs processing and if so call out to the driver to initialize hardware
1106 * and transfer each message.
1108 * Note that it is called both from the kthread itself and also from
1109 * inside spi_sync(); the queue extraction handling at the top of the
1110 * function should deal with this safely.
1112 static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
1114 unsigned long flags;
1115 bool was_busy = false;
1119 spin_lock_irqsave(&master->queue_lock, flags);
1121 /* Make sure we are not already running a message */
1122 if (master->cur_msg) {
1123 spin_unlock_irqrestore(&master->queue_lock, flags);
1127 /* If another context is idling the device then defer */
1128 if (master->idling) {
1129 kthread_queue_work(&master->kworker, &master->pump_messages);
1130 spin_unlock_irqrestore(&master->queue_lock, flags);
1134 /* Check if the queue is idle */
1135 if (list_empty(&master->queue) || !master->running) {
1136 if (!master->busy) {
1137 spin_unlock_irqrestore(&master->queue_lock, flags);
1141 /* Only do teardown in the thread */
1143 kthread_queue_work(&master->kworker,
1144 &master->pump_messages);
1145 spin_unlock_irqrestore(&master->queue_lock, flags);
1149 master->busy = false;
1150 master->idling = true;
1151 spin_unlock_irqrestore(&master->queue_lock, flags);
1153 kfree(master->dummy_rx);
1154 master->dummy_rx = NULL;
1155 kfree(master->dummy_tx);
1156 master->dummy_tx = NULL;
1157 if (master->unprepare_transfer_hardware &&
1158 master->unprepare_transfer_hardware(master))
1159 dev_err(&master->dev,
1160 "failed to unprepare transfer hardware\n");
1161 if (master->auto_runtime_pm) {
1162 pm_runtime_mark_last_busy(master->dev.parent);
1163 pm_runtime_put_autosuspend(master->dev.parent);
1165 trace_spi_master_idle(master);
1167 spin_lock_irqsave(&master->queue_lock, flags);
1168 master->idling = false;
1169 spin_unlock_irqrestore(&master->queue_lock, flags);
1173 /* Extract head of queue */
1175 list_first_entry(&master->queue, struct spi_message, queue);
1177 list_del_init(&master->cur_msg->queue);
1181 master->busy = true;
1182 spin_unlock_irqrestore(&master->queue_lock, flags);
1184 mutex_lock(&master->io_mutex);
1186 if (!was_busy && master->auto_runtime_pm) {
1187 ret = pm_runtime_get_sync(master->dev.parent);
1189 dev_err(&master->dev, "Failed to power device: %d\n",
1191 mutex_unlock(&master->io_mutex);
1197 trace_spi_master_busy(master);
1199 if (!was_busy && master->prepare_transfer_hardware) {
1200 ret = master->prepare_transfer_hardware(master);
1202 dev_err(&master->dev,
1203 "failed to prepare transfer hardware\n");
1205 if (master->auto_runtime_pm)
1206 pm_runtime_put(master->dev.parent);
1207 mutex_unlock(&master->io_mutex);
1212 trace_spi_message_start(master->cur_msg);
1214 if (master->prepare_message) {
1215 ret = master->prepare_message(master, master->cur_msg);
1217 dev_err(&master->dev,
1218 "failed to prepare message: %d\n", ret);
1219 master->cur_msg->status = ret;
1220 spi_finalize_current_message(master);
1223 master->cur_msg_prepared = true;
1226 ret = spi_map_msg(master, master->cur_msg);
1228 master->cur_msg->status = ret;
1229 spi_finalize_current_message(master);
1233 ret = master->transfer_one_message(master, master->cur_msg);
1235 dev_err(&master->dev,
1236 "failed to transfer one message from queue\n");
1241 mutex_unlock(&master->io_mutex);
1243 /* Prod the scheduler in case transfer_one() was busy waiting */
1249 * spi_pump_messages - kthread work function which processes spi message queue
1250 * @work: pointer to kthread work struct contained in the master struct
1252 static void spi_pump_messages(struct kthread_work *work)
1254 struct spi_master *master =
1255 container_of(work, struct spi_master, pump_messages);
1257 __spi_pump_messages(master, true);
1260 static int spi_init_queue(struct spi_master *master)
1262 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1264 master->running = false;
1265 master->busy = false;
1267 kthread_init_worker(&master->kworker);
1268 master->kworker_task = kthread_run(kthread_worker_fn,
1269 &master->kworker, "%s",
1270 dev_name(&master->dev));
1271 if (IS_ERR(master->kworker_task)) {
1272 dev_err(&master->dev, "failed to create message pump task\n");
1273 return PTR_ERR(master->kworker_task);
1275 kthread_init_work(&master->pump_messages, spi_pump_messages);
1278 * Master config will indicate if this controller should run the
1279 * message pump with high (realtime) priority to reduce the transfer
1280 * latency on the bus by minimising the delay between a transfer
1281 * request and the scheduling of the message pump thread. Without this
1282 * setting the message pump thread will remain at default priority.
1285 dev_info(&master->dev,
1286 "will run message pump with realtime priority\n");
1287 sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m);
1294 * spi_get_next_queued_message() - called by driver to check for queued
1296 * @master: the master to check for queued messages
1298 * If there are more messages in the queue, the next message is returned from
1301 * Return: the next message in the queue, else NULL if the queue is empty.
1303 struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1305 struct spi_message *next;
1306 unsigned long flags;
1308 /* get a pointer to the next message, if any */
1309 spin_lock_irqsave(&master->queue_lock, flags);
1310 next = list_first_entry_or_null(&master->queue, struct spi_message,
1312 spin_unlock_irqrestore(&master->queue_lock, flags);
1316 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1319 * spi_finalize_current_message() - the current message is complete
1320 * @master: the master to return the message to
1322 * Called by the driver to notify the core that the message in the front of the
1323 * queue is complete and can be removed from the queue.
1325 void spi_finalize_current_message(struct spi_master *master)
1327 struct spi_message *mesg;
1328 unsigned long flags;
1331 spin_lock_irqsave(&master->queue_lock, flags);
1332 mesg = master->cur_msg;
1333 spin_unlock_irqrestore(&master->queue_lock, flags);
1335 spi_unmap_msg(master, mesg);
1337 if (master->cur_msg_prepared && master->unprepare_message) {
1338 ret = master->unprepare_message(master, mesg);
1340 dev_err(&master->dev,
1341 "failed to unprepare message: %d\n", ret);
1345 spin_lock_irqsave(&master->queue_lock, flags);
1346 master->cur_msg = NULL;
1347 master->cur_msg_prepared = false;
1348 kthread_queue_work(&master->kworker, &master->pump_messages);
1349 spin_unlock_irqrestore(&master->queue_lock, flags);
1351 trace_spi_message_done(mesg);
1355 mesg->complete(mesg->context);
1357 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1359 static int spi_start_queue(struct spi_master *master)
1361 unsigned long flags;
1363 spin_lock_irqsave(&master->queue_lock, flags);
1365 if (master->running || master->busy) {
1366 spin_unlock_irqrestore(&master->queue_lock, flags);
1370 master->running = true;
1371 master->cur_msg = NULL;
1372 spin_unlock_irqrestore(&master->queue_lock, flags);
1374 kthread_queue_work(&master->kworker, &master->pump_messages);
1379 static int spi_stop_queue(struct spi_master *master)
1381 unsigned long flags;
1382 unsigned limit = 500;
1385 spin_lock_irqsave(&master->queue_lock, flags);
1388 * This is a bit lame, but is optimized for the common execution path.
1389 * A wait_queue on the master->busy could be used, but then the common
1390 * execution path (pump_messages) would be required to call wake_up or
1391 * friends on every SPI message. Do this instead.
1393 while ((!list_empty(&master->queue) || master->busy) && limit--) {
1394 spin_unlock_irqrestore(&master->queue_lock, flags);
1395 usleep_range(10000, 11000);
1396 spin_lock_irqsave(&master->queue_lock, flags);
1399 if (!list_empty(&master->queue) || master->busy)
1402 master->running = false;
1404 spin_unlock_irqrestore(&master->queue_lock, flags);
1407 dev_warn(&master->dev,
1408 "could not stop message queue\n");
1414 static int spi_destroy_queue(struct spi_master *master)
1418 ret = spi_stop_queue(master);
1421 * kthread_flush_worker will block until all work is done.
1422 * If the reason that stop_queue timed out is that the work will never
1423 * finish, then it does no good to call flush/stop thread, so
1427 dev_err(&master->dev, "problem destroying queue\n");
1431 kthread_flush_worker(&master->kworker);
1432 kthread_stop(master->kworker_task);
1437 static int __spi_queued_transfer(struct spi_device *spi,
1438 struct spi_message *msg,
1441 struct spi_master *master = spi->master;
1442 unsigned long flags;
1444 spin_lock_irqsave(&master->queue_lock, flags);
1446 if (!master->running) {
1447 spin_unlock_irqrestore(&master->queue_lock, flags);
1450 msg->actual_length = 0;
1451 msg->status = -EINPROGRESS;
1453 list_add_tail(&msg->queue, &master->queue);
1454 if (!master->busy && need_pump)
1455 kthread_queue_work(&master->kworker, &master->pump_messages);
1457 spin_unlock_irqrestore(&master->queue_lock, flags);
1462 * spi_queued_transfer - transfer function for queued transfers
1463 * @spi: spi device which is requesting transfer
1464 * @msg: spi message which is to handled is queued to driver queue
1466 * Return: zero on success, else a negative error code.
1468 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1470 return __spi_queued_transfer(spi, msg, true);
1473 static int spi_master_initialize_queue(struct spi_master *master)
1477 master->transfer = spi_queued_transfer;
1478 if (!master->transfer_one_message)
1479 master->transfer_one_message = spi_transfer_one_message;
1481 /* Initialize and start queue */
1482 ret = spi_init_queue(master);
1484 dev_err(&master->dev, "problem initializing queue\n");
1485 goto err_init_queue;
1487 master->queued = true;
1488 ret = spi_start_queue(master);
1490 dev_err(&master->dev, "problem starting queue\n");
1491 goto err_start_queue;
1497 spi_destroy_queue(master);
1502 /*-------------------------------------------------------------------------*/
1504 #if defined(CONFIG_OF)
1505 static struct spi_device *
1506 of_register_spi_device(struct spi_master *master, struct device_node *nc)
1508 struct spi_device *spi;
1512 /* Alloc an spi_device */
1513 spi = spi_alloc_device(master);
1515 dev_err(&master->dev, "spi_device alloc error for %s\n",
1521 /* Select device driver */
1522 rc = of_modalias_node(nc, spi->modalias,
1523 sizeof(spi->modalias));
1525 dev_err(&master->dev, "cannot find modalias for %s\n",
1530 /* Device address */
1531 rc = of_property_read_u32(nc, "reg", &value);
1533 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1537 spi->chip_select = value;
1539 /* Mode (clock phase/polarity/etc.) */
1540 if (of_find_property(nc, "spi-cpha", NULL))
1541 spi->mode |= SPI_CPHA;
1542 if (of_find_property(nc, "spi-cpol", NULL))
1543 spi->mode |= SPI_CPOL;
1544 if (of_find_property(nc, "spi-cs-high", NULL))
1545 spi->mode |= SPI_CS_HIGH;
1546 if (of_find_property(nc, "spi-3wire", NULL))
1547 spi->mode |= SPI_3WIRE;
1548 if (of_find_property(nc, "spi-lsb-first", NULL))
1549 spi->mode |= SPI_LSB_FIRST;
1551 /* Device DUAL/QUAD mode */
1552 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1557 spi->mode |= SPI_TX_DUAL;
1560 spi->mode |= SPI_TX_QUAD;
1563 dev_warn(&master->dev,
1564 "spi-tx-bus-width %d not supported\n",
1570 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1575 spi->mode |= SPI_RX_DUAL;
1578 spi->mode |= SPI_RX_QUAD;
1581 dev_warn(&master->dev,
1582 "spi-rx-bus-width %d not supported\n",
1589 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1591 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1595 spi->max_speed_hz = value;
1597 /* Store a pointer to the node in the device structure */
1599 spi->dev.of_node = nc;
1601 /* Register the new device */
1602 rc = spi_add_device(spi);
1604 dev_err(&master->dev, "spi_device register error %s\n",
1617 * of_register_spi_devices() - Register child devices onto the SPI bus
1618 * @master: Pointer to spi_master device
1620 * Registers an spi_device for each child node of master node which has a 'reg'
1623 static void of_register_spi_devices(struct spi_master *master)
1625 struct spi_device *spi;
1626 struct device_node *nc;
1628 if (!master->dev.of_node)
1631 for_each_available_child_of_node(master->dev.of_node, nc) {
1632 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1634 spi = of_register_spi_device(master, nc);
1636 dev_warn(&master->dev, "Failed to create SPI device for %s\n",
1638 of_node_clear_flag(nc, OF_POPULATED);
1643 static void of_register_spi_devices(struct spi_master *master) { }
1647 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1649 struct spi_device *spi = data;
1650 struct spi_master *master = spi->master;
1652 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1653 struct acpi_resource_spi_serialbus *sb;
1655 sb = &ares->data.spi_serial_bus;
1656 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1658 * ACPI DeviceSelection numbering is handled by the
1659 * host controller driver in Windows and can vary
1660 * from driver to driver. In Linux we always expect
1661 * 0 .. max - 1 so we need to ask the driver to
1662 * translate between the two schemes.
1664 if (master->fw_translate_cs) {
1665 int cs = master->fw_translate_cs(master,
1666 sb->device_selection);
1669 spi->chip_select = cs;
1671 spi->chip_select = sb->device_selection;
1674 spi->max_speed_hz = sb->connection_speed;
1676 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1677 spi->mode |= SPI_CPHA;
1678 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1679 spi->mode |= SPI_CPOL;
1680 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1681 spi->mode |= SPI_CS_HIGH;
1683 } else if (spi->irq < 0) {
1686 if (acpi_dev_resource_interrupt(ares, 0, &r))
1690 /* Always tell the ACPI core to skip this resource */
1694 static acpi_status acpi_register_spi_device(struct spi_master *master,
1695 struct acpi_device *adev)
1697 struct list_head resource_list;
1698 struct spi_device *spi;
1701 if (acpi_bus_get_status(adev) || !adev->status.present ||
1702 acpi_device_enumerated(adev))
1705 spi = spi_alloc_device(master);
1707 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1708 dev_name(&adev->dev));
1709 return AE_NO_MEMORY;
1712 ACPI_COMPANION_SET(&spi->dev, adev);
1715 INIT_LIST_HEAD(&resource_list);
1716 ret = acpi_dev_get_resources(adev, &resource_list,
1717 acpi_spi_add_resource, spi);
1718 acpi_dev_free_resource_list(&resource_list);
1720 if (ret < 0 || !spi->max_speed_hz) {
1726 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1728 acpi_device_set_enumerated(adev);
1730 adev->power.flags.ignore_parent = true;
1731 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
1732 if (spi_add_device(spi)) {
1733 adev->power.flags.ignore_parent = false;
1734 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1735 dev_name(&adev->dev));
1742 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1743 void *data, void **return_value)
1745 struct spi_master *master = data;
1746 struct acpi_device *adev;
1748 if (acpi_bus_get_device(handle, &adev))
1751 return acpi_register_spi_device(master, adev);
1754 static void acpi_register_spi_devices(struct spi_master *master)
1759 handle = ACPI_HANDLE(master->dev.parent);
1763 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1764 acpi_spi_add_device, NULL,
1766 if (ACPI_FAILURE(status))
1767 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1770 static inline void acpi_register_spi_devices(struct spi_master *master) {}
1771 #endif /* CONFIG_ACPI */
1773 static void spi_master_release(struct device *dev)
1775 struct spi_master *master;
1777 master = container_of(dev, struct spi_master, dev);
1781 static struct class spi_master_class = {
1782 .name = "spi_master",
1783 .owner = THIS_MODULE,
1784 .dev_release = spi_master_release,
1785 .dev_groups = spi_master_groups,
1790 * spi_alloc_master - allocate SPI master controller
1791 * @dev: the controller, possibly using the platform_bus
1792 * @size: how much zeroed driver-private data to allocate; the pointer to this
1793 * memory is in the driver_data field of the returned device,
1794 * accessible with spi_master_get_devdata().
1795 * Context: can sleep
1797 * This call is used only by SPI master controller drivers, which are the
1798 * only ones directly touching chip registers. It's how they allocate
1799 * an spi_master structure, prior to calling spi_register_master().
1801 * This must be called from context that can sleep.
1803 * The caller is responsible for assigning the bus number and initializing
1804 * the master's methods before calling spi_register_master(); and (after errors
1805 * adding the device) calling spi_master_put() to prevent a memory leak.
1807 * Return: the SPI master structure on success, else NULL.
1809 struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
1811 struct spi_master *master;
1816 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
1820 device_initialize(&master->dev);
1821 master->bus_num = -1;
1822 master->num_chipselect = 1;
1823 master->dev.class = &spi_master_class;
1824 master->dev.parent = dev;
1825 pm_suspend_ignore_children(&master->dev, true);
1826 spi_master_set_devdata(master, &master[1]);
1830 EXPORT_SYMBOL_GPL(spi_alloc_master);
1833 static int of_spi_register_master(struct spi_master *master)
1836 struct device_node *np = master->dev.of_node;
1841 nb = of_gpio_named_count(np, "cs-gpios");
1842 master->num_chipselect = max_t(int, nb, master->num_chipselect);
1844 /* Return error only for an incorrectly formed cs-gpios property */
1845 if (nb == 0 || nb == -ENOENT)
1850 cs = devm_kzalloc(&master->dev,
1851 sizeof(int) * master->num_chipselect,
1853 master->cs_gpios = cs;
1855 if (!master->cs_gpios)
1858 for (i = 0; i < master->num_chipselect; i++)
1861 for (i = 0; i < nb; i++)
1862 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1867 static int of_spi_register_master(struct spi_master *master)
1874 * spi_register_master - register SPI master controller
1875 * @master: initialized master, originally from spi_alloc_master()
1876 * Context: can sleep
1878 * SPI master controllers connect to their drivers using some non-SPI bus,
1879 * such as the platform bus. The final stage of probe() in that code
1880 * includes calling spi_register_master() to hook up to this SPI bus glue.
1882 * SPI controllers use board specific (often SOC specific) bus numbers,
1883 * and board-specific addressing for SPI devices combines those numbers
1884 * with chip select numbers. Since SPI does not directly support dynamic
1885 * device identification, boards need configuration tables telling which
1886 * chip is at which address.
1888 * This must be called from context that can sleep. It returns zero on
1889 * success, else a negative error code (dropping the master's refcount).
1890 * After a successful return, the caller is responsible for calling
1891 * spi_unregister_master().
1893 * Return: zero on success, else a negative error code.
1895 int spi_register_master(struct spi_master *master)
1897 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
1898 struct device *dev = master->dev.parent;
1899 struct boardinfo *bi;
1900 int status = -ENODEV;
1906 status = of_spi_register_master(master);
1910 /* even if it's just one always-selected device, there must
1911 * be at least one chipselect
1913 if (master->num_chipselect == 0)
1916 if ((master->bus_num < 0) && master->dev.of_node)
1917 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1919 /* convention: dynamically assigned bus IDs count down from the max */
1920 if (master->bus_num < 0) {
1921 /* FIXME switch to an IDR based scheme, something like
1922 * I2C now uses, so we can't run out of "dynamic" IDs
1924 master->bus_num = atomic_dec_return(&dyn_bus_id);
1928 INIT_LIST_HEAD(&master->queue);
1929 spin_lock_init(&master->queue_lock);
1930 spin_lock_init(&master->bus_lock_spinlock);
1931 mutex_init(&master->bus_lock_mutex);
1932 mutex_init(&master->io_mutex);
1933 master->bus_lock_flag = 0;
1934 init_completion(&master->xfer_completion);
1935 if (!master->max_dma_len)
1936 master->max_dma_len = INT_MAX;
1938 /* register the device, then userspace will see it.
1939 * registration fails if the bus ID is in use.
1941 dev_set_name(&master->dev, "spi%u", master->bus_num);
1942 status = device_add(&master->dev);
1945 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
1946 dynamic ? " (dynamic)" : "");
1948 /* If we're using a queued driver, start the queue */
1949 if (master->transfer)
1950 dev_info(dev, "master is unqueued, this is deprecated\n");
1952 status = spi_master_initialize_queue(master);
1954 device_del(&master->dev);
1958 /* add statistics */
1959 spin_lock_init(&master->statistics.lock);
1961 mutex_lock(&board_lock);
1962 list_add_tail(&master->list, &spi_master_list);
1963 list_for_each_entry(bi, &board_list, list)
1964 spi_match_master_to_boardinfo(master, &bi->board_info);
1965 mutex_unlock(&board_lock);
1967 /* Register devices from the device tree and ACPI */
1968 of_register_spi_devices(master);
1969 acpi_register_spi_devices(master);
1973 EXPORT_SYMBOL_GPL(spi_register_master);
1975 static void devm_spi_unregister(struct device *dev, void *res)
1977 spi_unregister_master(*(struct spi_master **)res);
1981 * dev_spi_register_master - register managed SPI master controller
1982 * @dev: device managing SPI master
1983 * @master: initialized master, originally from spi_alloc_master()
1984 * Context: can sleep
1986 * Register a SPI device as with spi_register_master() which will
1987 * automatically be unregister
1989 * Return: zero on success, else a negative error code.
1991 int devm_spi_register_master(struct device *dev, struct spi_master *master)
1993 struct spi_master **ptr;
1996 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2000 ret = spi_register_master(master);
2003 devres_add(dev, ptr);
2010 EXPORT_SYMBOL_GPL(devm_spi_register_master);
2012 static int __unregister(struct device *dev, void *null)
2014 spi_unregister_device(to_spi_device(dev));
2019 * spi_unregister_master - unregister SPI master controller
2020 * @master: the master being unregistered
2021 * Context: can sleep
2023 * This call is used only by SPI master controller drivers, which are the
2024 * only ones directly touching chip registers.
2026 * This must be called from context that can sleep.
2028 void spi_unregister_master(struct spi_master *master)
2032 if (master->queued) {
2033 if (spi_destroy_queue(master))
2034 dev_err(&master->dev, "queue remove failed\n");
2037 mutex_lock(&board_lock);
2038 list_del(&master->list);
2039 mutex_unlock(&board_lock);
2041 dummy = device_for_each_child(&master->dev, NULL, __unregister);
2042 device_unregister(&master->dev);
2044 EXPORT_SYMBOL_GPL(spi_unregister_master);
2046 int spi_master_suspend(struct spi_master *master)
2050 /* Basically no-ops for non-queued masters */
2051 if (!master->queued)
2054 ret = spi_stop_queue(master);
2056 dev_err(&master->dev, "queue stop failed\n");
2060 EXPORT_SYMBOL_GPL(spi_master_suspend);
2062 int spi_master_resume(struct spi_master *master)
2066 if (!master->queued)
2069 ret = spi_start_queue(master);
2071 dev_err(&master->dev, "queue restart failed\n");
2075 EXPORT_SYMBOL_GPL(spi_master_resume);
2077 static int __spi_master_match(struct device *dev, const void *data)
2079 struct spi_master *m;
2080 const u16 *bus_num = data;
2082 m = container_of(dev, struct spi_master, dev);
2083 return m->bus_num == *bus_num;
2087 * spi_busnum_to_master - look up master associated with bus_num
2088 * @bus_num: the master's bus number
2089 * Context: can sleep
2091 * This call may be used with devices that are registered after
2092 * arch init time. It returns a refcounted pointer to the relevant
2093 * spi_master (which the caller must release), or NULL if there is
2094 * no such master registered.
2096 * Return: the SPI master structure on success, else NULL.
2098 struct spi_master *spi_busnum_to_master(u16 bus_num)
2101 struct spi_master *master = NULL;
2103 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2104 __spi_master_match);
2106 master = container_of(dev, struct spi_master, dev);
2107 /* reference got in class_find_device */
2110 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2112 /*-------------------------------------------------------------------------*/
2114 /* Core methods for SPI resource management */
2117 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2118 * during the processing of a spi_message while using
2120 * @spi: the spi device for which we allocate memory
2121 * @release: the release code to execute for this resource
2122 * @size: size to alloc and return
2123 * @gfp: GFP allocation flags
2125 * Return: the pointer to the allocated data
2127 * This may get enhanced in the future to allocate from a memory pool
2128 * of the @spi_device or @spi_master to avoid repeated allocations.
2130 void *spi_res_alloc(struct spi_device *spi,
2131 spi_res_release_t release,
2132 size_t size, gfp_t gfp)
2134 struct spi_res *sres;
2136 sres = kzalloc(sizeof(*sres) + size, gfp);
2140 INIT_LIST_HEAD(&sres->entry);
2141 sres->release = release;
2145 EXPORT_SYMBOL_GPL(spi_res_alloc);
2148 * spi_res_free - free an spi resource
2149 * @res: pointer to the custom data of a resource
2152 void spi_res_free(void *res)
2154 struct spi_res *sres = container_of(res, struct spi_res, data);
2159 WARN_ON(!list_empty(&sres->entry));
2162 EXPORT_SYMBOL_GPL(spi_res_free);
2165 * spi_res_add - add a spi_res to the spi_message
2166 * @message: the spi message
2167 * @res: the spi_resource
2169 void spi_res_add(struct spi_message *message, void *res)
2171 struct spi_res *sres = container_of(res, struct spi_res, data);
2173 WARN_ON(!list_empty(&sres->entry));
2174 list_add_tail(&sres->entry, &message->resources);
2176 EXPORT_SYMBOL_GPL(spi_res_add);
2179 * spi_res_release - release all spi resources for this message
2180 * @master: the @spi_master
2181 * @message: the @spi_message
2183 void spi_res_release(struct spi_master *master,
2184 struct spi_message *message)
2186 struct spi_res *res;
2188 while (!list_empty(&message->resources)) {
2189 res = list_last_entry(&message->resources,
2190 struct spi_res, entry);
2193 res->release(master, message, res->data);
2195 list_del(&res->entry);
2200 EXPORT_SYMBOL_GPL(spi_res_release);
2202 /*-------------------------------------------------------------------------*/
2204 /* Core methods for spi_message alterations */
2206 static void __spi_replace_transfers_release(struct spi_master *master,
2207 struct spi_message *msg,
2210 struct spi_replaced_transfers *rxfer = res;
2213 /* call extra callback if requested */
2215 rxfer->release(master, msg, res);
2217 /* insert replaced transfers back into the message */
2218 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2220 /* remove the formerly inserted entries */
2221 for (i = 0; i < rxfer->inserted; i++)
2222 list_del(&rxfer->inserted_transfers[i].transfer_list);
2226 * spi_replace_transfers - replace transfers with several transfers
2227 * and register change with spi_message.resources
2228 * @msg: the spi_message we work upon
2229 * @xfer_first: the first spi_transfer we want to replace
2230 * @remove: number of transfers to remove
2231 * @insert: the number of transfers we want to insert instead
2232 * @release: extra release code necessary in some circumstances
2233 * @extradatasize: extra data to allocate (with alignment guarantees
2234 * of struct @spi_transfer)
2237 * Returns: pointer to @spi_replaced_transfers,
2238 * PTR_ERR(...) in case of errors.
2240 struct spi_replaced_transfers *spi_replace_transfers(
2241 struct spi_message *msg,
2242 struct spi_transfer *xfer_first,
2245 spi_replaced_release_t release,
2246 size_t extradatasize,
2249 struct spi_replaced_transfers *rxfer;
2250 struct spi_transfer *xfer;
2253 /* allocate the structure using spi_res */
2254 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2255 insert * sizeof(struct spi_transfer)
2256 + sizeof(struct spi_replaced_transfers)
2260 return ERR_PTR(-ENOMEM);
2262 /* the release code to invoke before running the generic release */
2263 rxfer->release = release;
2265 /* assign extradata */
2268 &rxfer->inserted_transfers[insert];
2270 /* init the replaced_transfers list */
2271 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2273 /* assign the list_entry after which we should reinsert
2274 * the @replaced_transfers - it may be spi_message.messages!
2276 rxfer->replaced_after = xfer_first->transfer_list.prev;
2278 /* remove the requested number of transfers */
2279 for (i = 0; i < remove; i++) {
2280 /* if the entry after replaced_after it is msg->transfers
2281 * then we have been requested to remove more transfers
2282 * than are in the list
2284 if (rxfer->replaced_after->next == &msg->transfers) {
2285 dev_err(&msg->spi->dev,
2286 "requested to remove more spi_transfers than are available\n");
2287 /* insert replaced transfers back into the message */
2288 list_splice(&rxfer->replaced_transfers,
2289 rxfer->replaced_after);
2291 /* free the spi_replace_transfer structure */
2292 spi_res_free(rxfer);
2294 /* and return with an error */
2295 return ERR_PTR(-EINVAL);
2298 /* remove the entry after replaced_after from list of
2299 * transfers and add it to list of replaced_transfers
2301 list_move_tail(rxfer->replaced_after->next,
2302 &rxfer->replaced_transfers);
2305 /* create copy of the given xfer with identical settings
2306 * based on the first transfer to get removed
2308 for (i = 0; i < insert; i++) {
2309 /* we need to run in reverse order */
2310 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2312 /* copy all spi_transfer data */
2313 memcpy(xfer, xfer_first, sizeof(*xfer));
2316 list_add(&xfer->transfer_list, rxfer->replaced_after);
2318 /* clear cs_change and delay_usecs for all but the last */
2320 xfer->cs_change = false;
2321 xfer->delay_usecs = 0;
2325 /* set up inserted */
2326 rxfer->inserted = insert;
2328 /* and register it with spi_res/spi_message */
2329 spi_res_add(msg, rxfer);
2333 EXPORT_SYMBOL_GPL(spi_replace_transfers);
2335 static int __spi_split_transfer_maxsize(struct spi_master *master,
2336 struct spi_message *msg,
2337 struct spi_transfer **xferp,
2341 struct spi_transfer *xfer = *xferp, *xfers;
2342 struct spi_replaced_transfers *srt;
2346 /* warn once about this fact that we are splitting a transfer */
2347 dev_warn_once(&msg->spi->dev,
2348 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2349 xfer->len, maxsize);
2351 /* calculate how many we have to replace */
2352 count = DIV_ROUND_UP(xfer->len, maxsize);
2354 /* create replacement */
2355 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
2357 return PTR_ERR(srt);
2358 xfers = srt->inserted_transfers;
2360 /* now handle each of those newly inserted spi_transfers
2361 * note that the replacements spi_transfers all are preset
2362 * to the same values as *xferp, so tx_buf, rx_buf and len
2363 * are all identical (as well as most others)
2364 * so we just have to fix up len and the pointers.
2366 * this also includes support for the depreciated
2367 * spi_message.is_dma_mapped interface
2370 /* the first transfer just needs the length modified, so we
2371 * run it outside the loop
2373 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
2375 /* all the others need rx_buf/tx_buf also set */
2376 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2377 /* update rx_buf, tx_buf and dma */
2378 if (xfers[i].rx_buf)
2379 xfers[i].rx_buf += offset;
2380 if (xfers[i].rx_dma)
2381 xfers[i].rx_dma += offset;
2382 if (xfers[i].tx_buf)
2383 xfers[i].tx_buf += offset;
2384 if (xfers[i].tx_dma)
2385 xfers[i].tx_dma += offset;
2388 xfers[i].len = min(maxsize, xfers[i].len - offset);
2391 /* we set up xferp to the last entry we have inserted,
2392 * so that we skip those already split transfers
2394 *xferp = &xfers[count - 1];
2396 /* increment statistics counters */
2397 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2398 transfers_split_maxsize);
2399 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2400 transfers_split_maxsize);
2406 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2407 * when an individual transfer exceeds a
2409 * @master: the @spi_master for this transfer
2410 * @msg: the @spi_message to transform
2411 * @maxsize: the maximum when to apply this
2412 * @gfp: GFP allocation flags
2414 * Return: status of transformation
2416 int spi_split_transfers_maxsize(struct spi_master *master,
2417 struct spi_message *msg,
2421 struct spi_transfer *xfer;
2424 /* iterate over the transfer_list,
2425 * but note that xfer is advanced to the last transfer inserted
2426 * to avoid checking sizes again unnecessarily (also xfer does
2427 * potentiall belong to a different list by the time the
2428 * replacement has happened
2430 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2431 if (xfer->len > maxsize) {
2432 ret = __spi_split_transfer_maxsize(
2433 master, msg, &xfer, maxsize, gfp);
2441 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2443 /*-------------------------------------------------------------------------*/
2445 /* Core methods for SPI master protocol drivers. Some of the
2446 * other core methods are currently defined as inline functions.
2449 static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2451 if (master->bits_per_word_mask) {
2452 /* Only 32 bits fit in the mask */
2453 if (bits_per_word > 32)
2455 if (!(master->bits_per_word_mask &
2456 SPI_BPW_MASK(bits_per_word)))
2464 * spi_setup - setup SPI mode and clock rate
2465 * @spi: the device whose settings are being modified
2466 * Context: can sleep, and no requests are queued to the device
2468 * SPI protocol drivers may need to update the transfer mode if the
2469 * device doesn't work with its default. They may likewise need
2470 * to update clock rates or word sizes from initial values. This function
2471 * changes those settings, and must be called from a context that can sleep.
2472 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2473 * effect the next time the device is selected and data is transferred to
2474 * or from it. When this function returns, the spi device is deselected.
2476 * Note that this call will fail if the protocol driver specifies an option
2477 * that the underlying controller or its driver does not support. For
2478 * example, not all hardware supports wire transfers using nine bit words,
2479 * LSB-first wire encoding, or active-high chipselects.
2481 * Return: zero on success, else a negative error code.
2483 int spi_setup(struct spi_device *spi)
2485 unsigned bad_bits, ugly_bits;
2488 /* check mode to prevent that DUAL and QUAD set at the same time
2490 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2491 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2493 "setup: can not select dual and quad at the same time\n");
2496 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2498 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2499 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2501 /* help drivers fail *cleanly* when they need options
2502 * that aren't supported with their current master
2504 bad_bits = spi->mode & ~spi->master->mode_bits;
2505 ugly_bits = bad_bits &
2506 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2509 "setup: ignoring unsupported mode bits %x\n",
2511 spi->mode &= ~ugly_bits;
2512 bad_bits &= ~ugly_bits;
2515 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
2520 if (!spi->bits_per_word)
2521 spi->bits_per_word = 8;
2523 status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2527 if (!spi->max_speed_hz)
2528 spi->max_speed_hz = spi->master->max_speed_hz;
2530 if (spi->master->setup)
2531 status = spi->master->setup(spi);
2533 spi_set_cs(spi, false);
2535 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2536 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2537 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2538 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2539 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2540 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2541 spi->bits_per_word, spi->max_speed_hz,
2546 EXPORT_SYMBOL_GPL(spi_setup);
2548 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
2550 struct spi_master *master = spi->master;
2551 struct spi_transfer *xfer;
2554 if (list_empty(&message->transfers))
2557 /* Half-duplex links include original MicroWire, and ones with
2558 * only one data pin like SPI_3WIRE (switches direction) or where
2559 * either MOSI or MISO is missing. They can also be caused by
2560 * software limitations.
2562 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2563 || (spi->mode & SPI_3WIRE)) {
2564 unsigned flags = master->flags;
2566 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2567 if (xfer->rx_buf && xfer->tx_buf)
2569 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2571 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2577 * Set transfer bits_per_word and max speed as spi device default if
2578 * it is not set for this transfer.
2579 * Set transfer tx_nbits and rx_nbits as single transfer default
2580 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2582 message->frame_length = 0;
2583 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2584 message->frame_length += xfer->len;
2585 if (!xfer->bits_per_word)
2586 xfer->bits_per_word = spi->bits_per_word;
2588 if (!xfer->speed_hz)
2589 xfer->speed_hz = spi->max_speed_hz;
2590 if (!xfer->speed_hz)
2591 xfer->speed_hz = master->max_speed_hz;
2593 if (master->max_speed_hz &&
2594 xfer->speed_hz > master->max_speed_hz)
2595 xfer->speed_hz = master->max_speed_hz;
2597 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2601 * SPI transfer length should be multiple of SPI word size
2602 * where SPI word size should be power-of-two multiple
2604 if (xfer->bits_per_word <= 8)
2606 else if (xfer->bits_per_word <= 16)
2611 /* No partial transfers accepted */
2612 if (xfer->len % w_size)
2615 if (xfer->speed_hz && master->min_speed_hz &&
2616 xfer->speed_hz < master->min_speed_hz)
2619 if (xfer->tx_buf && !xfer->tx_nbits)
2620 xfer->tx_nbits = SPI_NBITS_SINGLE;
2621 if (xfer->rx_buf && !xfer->rx_nbits)
2622 xfer->rx_nbits = SPI_NBITS_SINGLE;
2623 /* check transfer tx/rx_nbits:
2624 * 1. check the value matches one of single, dual and quad
2625 * 2. check tx/rx_nbits match the mode in spi_device
2628 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2629 xfer->tx_nbits != SPI_NBITS_DUAL &&
2630 xfer->tx_nbits != SPI_NBITS_QUAD)
2632 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2633 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2635 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2636 !(spi->mode & SPI_TX_QUAD))
2639 /* check transfer rx_nbits */
2641 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2642 xfer->rx_nbits != SPI_NBITS_DUAL &&
2643 xfer->rx_nbits != SPI_NBITS_QUAD)
2645 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2646 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2648 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2649 !(spi->mode & SPI_RX_QUAD))
2654 message->status = -EINPROGRESS;
2659 static int __spi_async(struct spi_device *spi, struct spi_message *message)
2661 struct spi_master *master = spi->master;
2665 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2666 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2668 trace_spi_message_submit(message);
2670 return master->transfer(spi, message);
2674 * spi_async - asynchronous SPI transfer
2675 * @spi: device with which data will be exchanged
2676 * @message: describes the data transfers, including completion callback
2677 * Context: any (irqs may be blocked, etc)
2679 * This call may be used in_irq and other contexts which can't sleep,
2680 * as well as from task contexts which can sleep.
2682 * The completion callback is invoked in a context which can't sleep.
2683 * Before that invocation, the value of message->status is undefined.
2684 * When the callback is issued, message->status holds either zero (to
2685 * indicate complete success) or a negative error code. After that
2686 * callback returns, the driver which issued the transfer request may
2687 * deallocate the associated memory; it's no longer in use by any SPI
2688 * core or controller driver code.
2690 * Note that although all messages to a spi_device are handled in
2691 * FIFO order, messages may go to different devices in other orders.
2692 * Some device might be higher priority, or have various "hard" access
2693 * time requirements, for example.
2695 * On detection of any fault during the transfer, processing of
2696 * the entire message is aborted, and the device is deselected.
2697 * Until returning from the associated message completion callback,
2698 * no other spi_message queued to that device will be processed.
2699 * (This rule applies equally to all the synchronous transfer calls,
2700 * which are wrappers around this core asynchronous primitive.)
2702 * Return: zero on success, else a negative error code.
2704 int spi_async(struct spi_device *spi, struct spi_message *message)
2706 struct spi_master *master = spi->master;
2708 unsigned long flags;
2710 ret = __spi_validate(spi, message);
2714 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2716 if (master->bus_lock_flag)
2719 ret = __spi_async(spi, message);
2721 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2725 EXPORT_SYMBOL_GPL(spi_async);
2728 * spi_async_locked - version of spi_async with exclusive bus usage
2729 * @spi: device with which data will be exchanged
2730 * @message: describes the data transfers, including completion callback
2731 * Context: any (irqs may be blocked, etc)
2733 * This call may be used in_irq and other contexts which can't sleep,
2734 * as well as from task contexts which can sleep.
2736 * The completion callback is invoked in a context which can't sleep.
2737 * Before that invocation, the value of message->status is undefined.
2738 * When the callback is issued, message->status holds either zero (to
2739 * indicate complete success) or a negative error code. After that
2740 * callback returns, the driver which issued the transfer request may
2741 * deallocate the associated memory; it's no longer in use by any SPI
2742 * core or controller driver code.
2744 * Note that although all messages to a spi_device are handled in
2745 * FIFO order, messages may go to different devices in other orders.
2746 * Some device might be higher priority, or have various "hard" access
2747 * time requirements, for example.
2749 * On detection of any fault during the transfer, processing of
2750 * the entire message is aborted, and the device is deselected.
2751 * Until returning from the associated message completion callback,
2752 * no other spi_message queued to that device will be processed.
2753 * (This rule applies equally to all the synchronous transfer calls,
2754 * which are wrappers around this core asynchronous primitive.)
2756 * Return: zero on success, else a negative error code.
2758 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2760 struct spi_master *master = spi->master;
2762 unsigned long flags;
2764 ret = __spi_validate(spi, message);
2768 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2770 ret = __spi_async(spi, message);
2772 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2777 EXPORT_SYMBOL_GPL(spi_async_locked);
2780 int spi_flash_read(struct spi_device *spi,
2781 struct spi_flash_read_message *msg)
2784 struct spi_master *master = spi->master;
2785 struct device *rx_dev = NULL;
2788 if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2789 msg->addr_nbits == SPI_NBITS_DUAL) &&
2790 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2792 if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2793 msg->addr_nbits == SPI_NBITS_QUAD) &&
2794 !(spi->mode & SPI_TX_QUAD))
2796 if (msg->data_nbits == SPI_NBITS_DUAL &&
2797 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2799 if (msg->data_nbits == SPI_NBITS_QUAD &&
2800 !(spi->mode & SPI_RX_QUAD))
2803 if (master->auto_runtime_pm) {
2804 ret = pm_runtime_get_sync(master->dev.parent);
2806 dev_err(&master->dev, "Failed to power device: %d\n",
2812 mutex_lock(&master->bus_lock_mutex);
2813 mutex_lock(&master->io_mutex);
2814 if (master->dma_rx) {
2815 rx_dev = master->dma_rx->device->dev;
2816 ret = spi_map_buf(master, rx_dev, &msg->rx_sg,
2820 msg->cur_msg_mapped = true;
2822 ret = master->spi_flash_read(spi, msg);
2823 if (msg->cur_msg_mapped)
2824 spi_unmap_buf(master, rx_dev, &msg->rx_sg,
2826 mutex_unlock(&master->io_mutex);
2827 mutex_unlock(&master->bus_lock_mutex);
2829 if (master->auto_runtime_pm)
2830 pm_runtime_put(master->dev.parent);
2834 EXPORT_SYMBOL_GPL(spi_flash_read);
2836 /*-------------------------------------------------------------------------*/
2838 /* Utility methods for SPI master protocol drivers, layered on
2839 * top of the core. Some other utility methods are defined as
2843 static void spi_complete(void *arg)
2848 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
2850 DECLARE_COMPLETION_ONSTACK(done);
2852 struct spi_master *master = spi->master;
2853 unsigned long flags;
2855 status = __spi_validate(spi, message);
2859 message->complete = spi_complete;
2860 message->context = &done;
2863 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2864 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2866 /* If we're not using the legacy transfer method then we will
2867 * try to transfer in the calling context so special case.
2868 * This code would be less tricky if we could remove the
2869 * support for driver implemented message queues.
2871 if (master->transfer == spi_queued_transfer) {
2872 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2874 trace_spi_message_submit(message);
2876 status = __spi_queued_transfer(spi, message, false);
2878 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2880 status = spi_async_locked(spi, message);
2884 /* Push out the messages in the calling context if we
2887 if (master->transfer == spi_queued_transfer) {
2888 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2889 spi_sync_immediate);
2890 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
2891 spi_sync_immediate);
2892 __spi_pump_messages(master, false);
2895 wait_for_completion(&done);
2896 status = message->status;
2898 message->context = NULL;
2903 * spi_sync - blocking/synchronous SPI data transfers
2904 * @spi: device with which data will be exchanged
2905 * @message: describes the data transfers
2906 * Context: can sleep
2908 * This call may only be used from a context that may sleep. The sleep
2909 * is non-interruptible, and has no timeout. Low-overhead controller
2910 * drivers may DMA directly into and out of the message buffers.
2912 * Note that the SPI device's chip select is active during the message,
2913 * and then is normally disabled between messages. Drivers for some
2914 * frequently-used devices may want to minimize costs of selecting a chip,
2915 * by leaving it selected in anticipation that the next message will go
2916 * to the same chip. (That may increase power usage.)
2918 * Also, the caller is guaranteeing that the memory associated with the
2919 * message will not be freed before this call returns.
2921 * Return: zero on success, else a negative error code.
2923 int spi_sync(struct spi_device *spi, struct spi_message *message)
2927 mutex_lock(&spi->master->bus_lock_mutex);
2928 ret = __spi_sync(spi, message);
2929 mutex_unlock(&spi->master->bus_lock_mutex);
2933 EXPORT_SYMBOL_GPL(spi_sync);
2936 * spi_sync_locked - version of spi_sync with exclusive bus usage
2937 * @spi: device with which data will be exchanged
2938 * @message: describes the data transfers
2939 * Context: can sleep
2941 * This call may only be used from a context that may sleep. The sleep
2942 * is non-interruptible, and has no timeout. Low-overhead controller
2943 * drivers may DMA directly into and out of the message buffers.
2945 * This call should be used by drivers that require exclusive access to the
2946 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
2947 * be released by a spi_bus_unlock call when the exclusive access is over.
2949 * Return: zero on success, else a negative error code.
2951 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2953 return __spi_sync(spi, message);
2955 EXPORT_SYMBOL_GPL(spi_sync_locked);
2958 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2959 * @master: SPI bus master that should be locked for exclusive bus access
2960 * Context: can sleep
2962 * This call may only be used from a context that may sleep. The sleep
2963 * is non-interruptible, and has no timeout.
2965 * This call should be used by drivers that require exclusive access to the
2966 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2967 * exclusive access is over. Data transfer must be done by spi_sync_locked
2968 * and spi_async_locked calls when the SPI bus lock is held.
2970 * Return: always zero.
2972 int spi_bus_lock(struct spi_master *master)
2974 unsigned long flags;
2976 mutex_lock(&master->bus_lock_mutex);
2978 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2979 master->bus_lock_flag = 1;
2980 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2982 /* mutex remains locked until spi_bus_unlock is called */
2986 EXPORT_SYMBOL_GPL(spi_bus_lock);
2989 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2990 * @master: SPI bus master that was locked for exclusive bus access
2991 * Context: can sleep
2993 * This call may only be used from a context that may sleep. The sleep
2994 * is non-interruptible, and has no timeout.
2996 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2999 * Return: always zero.
3001 int spi_bus_unlock(struct spi_master *master)
3003 master->bus_lock_flag = 0;
3005 mutex_unlock(&master->bus_lock_mutex);
3009 EXPORT_SYMBOL_GPL(spi_bus_unlock);
3011 /* portable code must never pass more than 32 bytes */
3012 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3017 * spi_write_then_read - SPI synchronous write followed by read
3018 * @spi: device with which data will be exchanged
3019 * @txbuf: data to be written (need not be dma-safe)
3020 * @n_tx: size of txbuf, in bytes
3021 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3022 * @n_rx: size of rxbuf, in bytes
3023 * Context: can sleep
3025 * This performs a half duplex MicroWire style transaction with the
3026 * device, sending txbuf and then reading rxbuf. The return value
3027 * is zero for success, else a negative errno status code.
3028 * This call may only be used from a context that may sleep.
3030 * Parameters to this routine are always copied using a small buffer;
3031 * portable code should never use this for more than 32 bytes.
3032 * Performance-sensitive or bulk transfer code should instead use
3033 * spi_{async,sync}() calls with dma-safe buffers.
3035 * Return: zero on success, else a negative error code.
3037 int spi_write_then_read(struct spi_device *spi,
3038 const void *txbuf, unsigned n_tx,
3039 void *rxbuf, unsigned n_rx)
3041 static DEFINE_MUTEX(lock);
3044 struct spi_message message;
3045 struct spi_transfer x[2];
3048 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3049 * copying here, (as a pure convenience thing), but we can
3050 * keep heap costs out of the hot path unless someone else is
3051 * using the pre-allocated buffer or the transfer is too large.
3053 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
3054 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3055 GFP_KERNEL | GFP_DMA);
3062 spi_message_init(&message);
3063 memset(x, 0, sizeof(x));
3066 spi_message_add_tail(&x[0], &message);
3070 spi_message_add_tail(&x[1], &message);
3073 memcpy(local_buf, txbuf, n_tx);
3074 x[0].tx_buf = local_buf;
3075 x[1].rx_buf = local_buf + n_tx;
3078 status = spi_sync(spi, &message);
3080 memcpy(rxbuf, x[1].rx_buf, n_rx);
3082 if (x[0].tx_buf == buf)
3083 mutex_unlock(&lock);
3089 EXPORT_SYMBOL_GPL(spi_write_then_read);
3091 /*-------------------------------------------------------------------------*/
3093 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
3094 static int __spi_of_device_match(struct device *dev, void *data)
3096 return dev->of_node == data;
3099 /* must call put_device() when done with returned spi_device device */
3100 static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3102 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3103 __spi_of_device_match);
3104 return dev ? to_spi_device(dev) : NULL;
3107 static int __spi_of_master_match(struct device *dev, const void *data)
3109 return dev->of_node == data;
3112 /* the spi masters are not using spi_bus, so we find it with another way */
3113 static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3117 dev = class_find_device(&spi_master_class, NULL, node,
3118 __spi_of_master_match);
3122 /* reference got in class_find_device */
3123 return container_of(dev, struct spi_master, dev);
3126 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3129 struct of_reconfig_data *rd = arg;
3130 struct spi_master *master;
3131 struct spi_device *spi;
3133 switch (of_reconfig_get_state_change(action, arg)) {
3134 case OF_RECONFIG_CHANGE_ADD:
3135 master = of_find_spi_master_by_node(rd->dn->parent);
3137 return NOTIFY_OK; /* not for us */
3139 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3140 put_device(&master->dev);
3144 spi = of_register_spi_device(master, rd->dn);
3145 put_device(&master->dev);
3148 pr_err("%s: failed to create for '%s'\n",
3149 __func__, rd->dn->full_name);
3150 of_node_clear_flag(rd->dn, OF_POPULATED);
3151 return notifier_from_errno(PTR_ERR(spi));
3155 case OF_RECONFIG_CHANGE_REMOVE:
3156 /* already depopulated? */
3157 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3160 /* find our device by node */
3161 spi = of_find_spi_device_by_node(rd->dn);
3163 return NOTIFY_OK; /* no? not meant for us */
3165 /* unregister takes one ref away */
3166 spi_unregister_device(spi);
3168 /* and put the reference of the find */
3169 put_device(&spi->dev);
3176 static struct notifier_block spi_of_notifier = {
3177 .notifier_call = of_spi_notify,
3179 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3180 extern struct notifier_block spi_of_notifier;
3181 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3183 #if IS_ENABLED(CONFIG_ACPI)
3184 static int spi_acpi_master_match(struct device *dev, const void *data)
3186 return ACPI_COMPANION(dev->parent) == data;
3189 static int spi_acpi_device_match(struct device *dev, void *data)
3191 return ACPI_COMPANION(dev) == data;
3194 static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device *adev)
3198 dev = class_find_device(&spi_master_class, NULL, adev,
3199 spi_acpi_master_match);
3203 return container_of(dev, struct spi_master, dev);
3206 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3210 dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3212 return dev ? to_spi_device(dev) : NULL;
3215 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3218 struct acpi_device *adev = arg;
3219 struct spi_master *master;
3220 struct spi_device *spi;
3223 case ACPI_RECONFIG_DEVICE_ADD:
3224 master = acpi_spi_find_master_by_adev(adev->parent);
3228 acpi_register_spi_device(master, adev);
3229 put_device(&master->dev);
3231 case ACPI_RECONFIG_DEVICE_REMOVE:
3232 if (!acpi_device_enumerated(adev))
3235 spi = acpi_spi_find_device_by_adev(adev);
3239 spi_unregister_device(spi);
3240 put_device(&spi->dev);
3247 static struct notifier_block spi_acpi_notifier = {
3248 .notifier_call = acpi_spi_notify,
3251 extern struct notifier_block spi_acpi_notifier;
3254 static int __init spi_init(void)
3258 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
3264 status = bus_register(&spi_bus_type);
3268 status = class_register(&spi_master_class);
3272 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
3273 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3274 if (IS_ENABLED(CONFIG_ACPI))
3275 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
3280 bus_unregister(&spi_bus_type);
3288 /* board_info is normally registered in arch_initcall(),
3289 * but even essential drivers wait till later
3291 * REVISIT only boardinfo really needs static linking. the rest (device and
3292 * driver registration) _could_ be dynamically linked (modular) ... costs
3293 * include needing to have boardinfo data structures be much more public.
3295 postcore_initcall(spi_init);