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 of_node_put(spi->dev.of_node);
628 if (ACPI_COMPANION(&spi->dev))
629 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
630 device_unregister(&spi->dev);
632 EXPORT_SYMBOL_GPL(spi_unregister_device);
634 static void spi_match_master_to_boardinfo(struct spi_master *master,
635 struct spi_board_info *bi)
637 struct spi_device *dev;
639 if (master->bus_num != bi->bus_num)
642 dev = spi_new_device(master, bi);
644 dev_err(master->dev.parent, "can't create new device for %s\n",
649 * spi_register_board_info - register SPI devices for a given board
650 * @info: array of chip descriptors
651 * @n: how many descriptors are provided
654 * Board-specific early init code calls this (probably during arch_initcall)
655 * with segments of the SPI device table. Any device nodes are created later,
656 * after the relevant parent SPI controller (bus_num) is defined. We keep
657 * this table of devices forever, so that reloading a controller driver will
658 * not make Linux forget about these hard-wired devices.
660 * Other code can also call this, e.g. a particular add-on board might provide
661 * SPI devices through its expansion connector, so code initializing that board
662 * would naturally declare its SPI devices.
664 * The board info passed can safely be __initdata ... but be careful of
665 * any embedded pointers (platform_data, etc), they're copied as-is.
667 * Return: zero on success, else a negative error code.
669 int spi_register_board_info(struct spi_board_info const *info, unsigned n)
671 struct boardinfo *bi;
677 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
681 for (i = 0; i < n; i++, bi++, info++) {
682 struct spi_master *master;
684 memcpy(&bi->board_info, info, sizeof(*info));
685 mutex_lock(&board_lock);
686 list_add_tail(&bi->list, &board_list);
687 list_for_each_entry(master, &spi_master_list, list)
688 spi_match_master_to_boardinfo(master, &bi->board_info);
689 mutex_unlock(&board_lock);
695 /*-------------------------------------------------------------------------*/
697 static void spi_set_cs(struct spi_device *spi, bool enable)
699 if (spi->mode & SPI_CS_HIGH)
702 if (gpio_is_valid(spi->cs_gpio)) {
703 gpio_set_value(spi->cs_gpio, !enable);
704 /* Some SPI masters need both GPIO CS & slave_select */
705 if ((spi->master->flags & SPI_MASTER_GPIO_SS) &&
707 spi->master->set_cs(spi, !enable);
708 } else if (spi->master->set_cs) {
709 spi->master->set_cs(spi, !enable);
713 #ifdef CONFIG_HAS_DMA
714 static int spi_map_buf(struct spi_master *master, struct device *dev,
715 struct sg_table *sgt, void *buf, size_t len,
716 enum dma_data_direction dir)
718 const bool vmalloced_buf = is_vmalloc_addr(buf);
719 unsigned int max_seg_size = dma_get_max_seg_size(dev);
720 #ifdef CONFIG_HIGHMEM
721 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
722 (unsigned long)buf < (PKMAP_BASE +
723 (LAST_PKMAP * PAGE_SIZE)));
725 const bool kmap_buf = false;
729 struct page *vm_page;
730 struct scatterlist *sg;
735 if (vmalloced_buf || kmap_buf) {
736 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
737 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
738 } else if (virt_addr_valid(buf)) {
739 desc_len = min_t(int, max_seg_size, master->max_dma_len);
740 sgs = DIV_ROUND_UP(len, desc_len);
745 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
750 for (i = 0; i < sgs; i++) {
752 if (vmalloced_buf || kmap_buf) {
754 len, desc_len - offset_in_page(buf));
756 vm_page = vmalloc_to_page(buf);
758 vm_page = kmap_to_page(buf);
763 sg_set_page(sg, vm_page,
764 min, offset_in_page(buf));
766 min = min_t(size_t, len, desc_len);
768 sg_set_buf(sg, sg_buf, min);
776 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
789 static void spi_unmap_buf(struct spi_master *master, struct device *dev,
790 struct sg_table *sgt, enum dma_data_direction dir)
792 if (sgt->orig_nents) {
793 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
798 static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
800 struct device *tx_dev, *rx_dev;
801 struct spi_transfer *xfer;
804 if (!master->can_dma)
808 tx_dev = master->dma_tx->device->dev;
810 tx_dev = &master->dev;
813 rx_dev = master->dma_rx->device->dev;
815 rx_dev = &master->dev;
817 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
818 if (!master->can_dma(master, msg->spi, xfer))
821 if (xfer->tx_buf != NULL) {
822 ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
823 (void *)xfer->tx_buf, xfer->len,
829 if (xfer->rx_buf != NULL) {
830 ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
831 xfer->rx_buf, xfer->len,
834 spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
841 master->cur_msg_mapped = true;
846 static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
848 struct spi_transfer *xfer;
849 struct device *tx_dev, *rx_dev;
851 if (!master->cur_msg_mapped || !master->can_dma)
855 tx_dev = master->dma_tx->device->dev;
857 tx_dev = &master->dev;
860 rx_dev = master->dma_rx->device->dev;
862 rx_dev = &master->dev;
864 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
865 if (!master->can_dma(master, msg->spi, xfer))
868 spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
869 spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
874 #else /* !CONFIG_HAS_DMA */
875 static inline int spi_map_buf(struct spi_master *master,
876 struct device *dev, struct sg_table *sgt,
877 void *buf, size_t len,
878 enum dma_data_direction dir)
883 static inline void spi_unmap_buf(struct spi_master *master,
884 struct device *dev, struct sg_table *sgt,
885 enum dma_data_direction dir)
889 static inline int __spi_map_msg(struct spi_master *master,
890 struct spi_message *msg)
895 static inline int __spi_unmap_msg(struct spi_master *master,
896 struct spi_message *msg)
900 #endif /* !CONFIG_HAS_DMA */
902 static inline int spi_unmap_msg(struct spi_master *master,
903 struct spi_message *msg)
905 struct spi_transfer *xfer;
907 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
909 * Restore the original value of tx_buf or rx_buf if they are
912 if (xfer->tx_buf == master->dummy_tx)
914 if (xfer->rx_buf == master->dummy_rx)
918 return __spi_unmap_msg(master, msg);
921 static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
923 struct spi_transfer *xfer;
925 unsigned int max_tx, max_rx;
927 if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
931 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
932 if ((master->flags & SPI_MASTER_MUST_TX) &&
934 max_tx = max(xfer->len, max_tx);
935 if ((master->flags & SPI_MASTER_MUST_RX) &&
937 max_rx = max(xfer->len, max_rx);
941 tmp = krealloc(master->dummy_tx, max_tx,
942 GFP_KERNEL | GFP_DMA);
945 master->dummy_tx = tmp;
946 memset(tmp, 0, max_tx);
950 tmp = krealloc(master->dummy_rx, max_rx,
951 GFP_KERNEL | GFP_DMA);
954 master->dummy_rx = tmp;
957 if (max_tx || max_rx) {
958 list_for_each_entry(xfer, &msg->transfers,
961 xfer->tx_buf = master->dummy_tx;
963 xfer->rx_buf = master->dummy_rx;
968 return __spi_map_msg(master, msg);
972 * spi_transfer_one_message - Default implementation of transfer_one_message()
974 * This is a standard implementation of transfer_one_message() for
975 * drivers which implement a transfer_one() operation. It provides
976 * standard handling of delays and chip select management.
978 static int spi_transfer_one_message(struct spi_master *master,
979 struct spi_message *msg)
981 struct spi_transfer *xfer;
982 bool keep_cs = false;
984 unsigned long long ms = 1;
985 struct spi_statistics *statm = &master->statistics;
986 struct spi_statistics *stats = &msg->spi->statistics;
988 spi_set_cs(msg->spi, true);
990 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
991 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
993 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
994 trace_spi_transfer_start(msg, xfer);
996 spi_statistics_add_transfer_stats(statm, xfer, master);
997 spi_statistics_add_transfer_stats(stats, xfer, master);
999 if (xfer->tx_buf || xfer->rx_buf) {
1000 reinit_completion(&master->xfer_completion);
1002 ret = master->transfer_one(master, msg->spi, xfer);
1004 SPI_STATISTICS_INCREMENT_FIELD(statm,
1006 SPI_STATISTICS_INCREMENT_FIELD(stats,
1008 dev_err(&msg->spi->dev,
1009 "SPI transfer failed: %d\n", ret);
1015 ms = 8LL * 1000LL * xfer->len;
1016 do_div(ms, xfer->speed_hz);
1017 ms += ms + 100; /* some tolerance */
1022 ms = wait_for_completion_timeout(&master->xfer_completion,
1023 msecs_to_jiffies(ms));
1027 SPI_STATISTICS_INCREMENT_FIELD(statm,
1029 SPI_STATISTICS_INCREMENT_FIELD(stats,
1031 dev_err(&msg->spi->dev,
1032 "SPI transfer timed out\n");
1033 msg->status = -ETIMEDOUT;
1037 dev_err(&msg->spi->dev,
1038 "Bufferless transfer has length %u\n",
1042 trace_spi_transfer_stop(msg, xfer);
1044 if (msg->status != -EINPROGRESS)
1047 if (xfer->delay_usecs) {
1048 u16 us = xfer->delay_usecs;
1053 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1056 if (xfer->cs_change) {
1057 if (list_is_last(&xfer->transfer_list,
1061 spi_set_cs(msg->spi, false);
1063 spi_set_cs(msg->spi, true);
1067 msg->actual_length += xfer->len;
1071 if (ret != 0 || !keep_cs)
1072 spi_set_cs(msg->spi, false);
1074 if (msg->status == -EINPROGRESS)
1077 if (msg->status && master->handle_err)
1078 master->handle_err(master, msg);
1080 spi_res_release(master, msg);
1082 spi_finalize_current_message(master);
1088 * spi_finalize_current_transfer - report completion of a transfer
1089 * @master: the master reporting completion
1091 * Called by SPI drivers using the core transfer_one_message()
1092 * implementation to notify it that the current interrupt driven
1093 * transfer has finished and the next one may be scheduled.
1095 void spi_finalize_current_transfer(struct spi_master *master)
1097 complete(&master->xfer_completion);
1099 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1102 * __spi_pump_messages - function which processes spi message queue
1103 * @master: master to process queue for
1104 * @in_kthread: true if we are in the context of the message pump thread
1106 * This function checks if there is any spi message in the queue that
1107 * needs processing and if so call out to the driver to initialize hardware
1108 * and transfer each message.
1110 * Note that it is called both from the kthread itself and also from
1111 * inside spi_sync(); the queue extraction handling at the top of the
1112 * function should deal with this safely.
1114 static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
1116 unsigned long flags;
1117 bool was_busy = false;
1121 spin_lock_irqsave(&master->queue_lock, flags);
1123 /* Make sure we are not already running a message */
1124 if (master->cur_msg) {
1125 spin_unlock_irqrestore(&master->queue_lock, flags);
1129 /* If another context is idling the device then defer */
1130 if (master->idling) {
1131 kthread_queue_work(&master->kworker, &master->pump_messages);
1132 spin_unlock_irqrestore(&master->queue_lock, flags);
1136 /* Check if the queue is idle */
1137 if (list_empty(&master->queue) || !master->running) {
1138 if (!master->busy) {
1139 spin_unlock_irqrestore(&master->queue_lock, flags);
1143 /* Only do teardown in the thread */
1145 kthread_queue_work(&master->kworker,
1146 &master->pump_messages);
1147 spin_unlock_irqrestore(&master->queue_lock, flags);
1151 master->busy = false;
1152 master->idling = true;
1153 spin_unlock_irqrestore(&master->queue_lock, flags);
1155 kfree(master->dummy_rx);
1156 master->dummy_rx = NULL;
1157 kfree(master->dummy_tx);
1158 master->dummy_tx = NULL;
1159 if (master->unprepare_transfer_hardware &&
1160 master->unprepare_transfer_hardware(master))
1161 dev_err(&master->dev,
1162 "failed to unprepare transfer hardware\n");
1163 if (master->auto_runtime_pm) {
1164 pm_runtime_mark_last_busy(master->dev.parent);
1165 pm_runtime_put_autosuspend(master->dev.parent);
1167 trace_spi_master_idle(master);
1169 spin_lock_irqsave(&master->queue_lock, flags);
1170 master->idling = false;
1171 spin_unlock_irqrestore(&master->queue_lock, flags);
1175 /* Extract head of queue */
1177 list_first_entry(&master->queue, struct spi_message, queue);
1179 list_del_init(&master->cur_msg->queue);
1183 master->busy = true;
1184 spin_unlock_irqrestore(&master->queue_lock, flags);
1186 mutex_lock(&master->io_mutex);
1188 if (!was_busy && master->auto_runtime_pm) {
1189 ret = pm_runtime_get_sync(master->dev.parent);
1191 dev_err(&master->dev, "Failed to power device: %d\n",
1193 mutex_unlock(&master->io_mutex);
1199 trace_spi_master_busy(master);
1201 if (!was_busy && master->prepare_transfer_hardware) {
1202 ret = master->prepare_transfer_hardware(master);
1204 dev_err(&master->dev,
1205 "failed to prepare transfer hardware\n");
1207 if (master->auto_runtime_pm)
1208 pm_runtime_put(master->dev.parent);
1209 mutex_unlock(&master->io_mutex);
1214 trace_spi_message_start(master->cur_msg);
1216 if (master->prepare_message) {
1217 ret = master->prepare_message(master, master->cur_msg);
1219 dev_err(&master->dev,
1220 "failed to prepare message: %d\n", ret);
1221 master->cur_msg->status = ret;
1222 spi_finalize_current_message(master);
1225 master->cur_msg_prepared = true;
1228 ret = spi_map_msg(master, master->cur_msg);
1230 master->cur_msg->status = ret;
1231 spi_finalize_current_message(master);
1235 ret = master->transfer_one_message(master, master->cur_msg);
1237 dev_err(&master->dev,
1238 "failed to transfer one message from queue\n");
1243 mutex_unlock(&master->io_mutex);
1245 /* Prod the scheduler in case transfer_one() was busy waiting */
1251 * spi_pump_messages - kthread work function which processes spi message queue
1252 * @work: pointer to kthread work struct contained in the master struct
1254 static void spi_pump_messages(struct kthread_work *work)
1256 struct spi_master *master =
1257 container_of(work, struct spi_master, pump_messages);
1259 __spi_pump_messages(master, true);
1262 static int spi_init_queue(struct spi_master *master)
1264 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1266 master->running = false;
1267 master->busy = false;
1269 kthread_init_worker(&master->kworker);
1270 master->kworker_task = kthread_run(kthread_worker_fn,
1271 &master->kworker, "%s",
1272 dev_name(&master->dev));
1273 if (IS_ERR(master->kworker_task)) {
1274 dev_err(&master->dev, "failed to create message pump task\n");
1275 return PTR_ERR(master->kworker_task);
1277 kthread_init_work(&master->pump_messages, spi_pump_messages);
1280 * Master config will indicate if this controller should run the
1281 * message pump with high (realtime) priority to reduce the transfer
1282 * latency on the bus by minimising the delay between a transfer
1283 * request and the scheduling of the message pump thread. Without this
1284 * setting the message pump thread will remain at default priority.
1287 dev_info(&master->dev,
1288 "will run message pump with realtime priority\n");
1289 sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m);
1296 * spi_get_next_queued_message() - called by driver to check for queued
1298 * @master: the master to check for queued messages
1300 * If there are more messages in the queue, the next message is returned from
1303 * Return: the next message in the queue, else NULL if the queue is empty.
1305 struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1307 struct spi_message *next;
1308 unsigned long flags;
1310 /* get a pointer to the next message, if any */
1311 spin_lock_irqsave(&master->queue_lock, flags);
1312 next = list_first_entry_or_null(&master->queue, struct spi_message,
1314 spin_unlock_irqrestore(&master->queue_lock, flags);
1318 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1321 * spi_finalize_current_message() - the current message is complete
1322 * @master: the master to return the message to
1324 * Called by the driver to notify the core that the message in the front of the
1325 * queue is complete and can be removed from the queue.
1327 void spi_finalize_current_message(struct spi_master *master)
1329 struct spi_message *mesg;
1330 unsigned long flags;
1333 spin_lock_irqsave(&master->queue_lock, flags);
1334 mesg = master->cur_msg;
1335 spin_unlock_irqrestore(&master->queue_lock, flags);
1337 spi_unmap_msg(master, mesg);
1339 if (master->cur_msg_prepared && master->unprepare_message) {
1340 ret = master->unprepare_message(master, mesg);
1342 dev_err(&master->dev,
1343 "failed to unprepare message: %d\n", ret);
1347 spin_lock_irqsave(&master->queue_lock, flags);
1348 master->cur_msg = NULL;
1349 master->cur_msg_prepared = false;
1350 kthread_queue_work(&master->kworker, &master->pump_messages);
1351 spin_unlock_irqrestore(&master->queue_lock, flags);
1353 trace_spi_message_done(mesg);
1357 mesg->complete(mesg->context);
1359 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1361 static int spi_start_queue(struct spi_master *master)
1363 unsigned long flags;
1365 spin_lock_irqsave(&master->queue_lock, flags);
1367 if (master->running || master->busy) {
1368 spin_unlock_irqrestore(&master->queue_lock, flags);
1372 master->running = true;
1373 master->cur_msg = NULL;
1374 spin_unlock_irqrestore(&master->queue_lock, flags);
1376 kthread_queue_work(&master->kworker, &master->pump_messages);
1381 static int spi_stop_queue(struct spi_master *master)
1383 unsigned long flags;
1384 unsigned limit = 500;
1387 spin_lock_irqsave(&master->queue_lock, flags);
1390 * This is a bit lame, but is optimized for the common execution path.
1391 * A wait_queue on the master->busy could be used, but then the common
1392 * execution path (pump_messages) would be required to call wake_up or
1393 * friends on every SPI message. Do this instead.
1395 while ((!list_empty(&master->queue) || master->busy) && limit--) {
1396 spin_unlock_irqrestore(&master->queue_lock, flags);
1397 usleep_range(10000, 11000);
1398 spin_lock_irqsave(&master->queue_lock, flags);
1401 if (!list_empty(&master->queue) || master->busy)
1404 master->running = false;
1406 spin_unlock_irqrestore(&master->queue_lock, flags);
1409 dev_warn(&master->dev,
1410 "could not stop message queue\n");
1416 static int spi_destroy_queue(struct spi_master *master)
1420 ret = spi_stop_queue(master);
1423 * kthread_flush_worker will block until all work is done.
1424 * If the reason that stop_queue timed out is that the work will never
1425 * finish, then it does no good to call flush/stop thread, so
1429 dev_err(&master->dev, "problem destroying queue\n");
1433 kthread_flush_worker(&master->kworker);
1434 kthread_stop(master->kworker_task);
1439 static int __spi_queued_transfer(struct spi_device *spi,
1440 struct spi_message *msg,
1443 struct spi_master *master = spi->master;
1444 unsigned long flags;
1446 spin_lock_irqsave(&master->queue_lock, flags);
1448 if (!master->running) {
1449 spin_unlock_irqrestore(&master->queue_lock, flags);
1452 msg->actual_length = 0;
1453 msg->status = -EINPROGRESS;
1455 list_add_tail(&msg->queue, &master->queue);
1456 if (!master->busy && need_pump)
1457 kthread_queue_work(&master->kworker, &master->pump_messages);
1459 spin_unlock_irqrestore(&master->queue_lock, flags);
1464 * spi_queued_transfer - transfer function for queued transfers
1465 * @spi: spi device which is requesting transfer
1466 * @msg: spi message which is to handled is queued to driver queue
1468 * Return: zero on success, else a negative error code.
1470 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1472 return __spi_queued_transfer(spi, msg, true);
1475 static int spi_master_initialize_queue(struct spi_master *master)
1479 master->transfer = spi_queued_transfer;
1480 if (!master->transfer_one_message)
1481 master->transfer_one_message = spi_transfer_one_message;
1483 /* Initialize and start queue */
1484 ret = spi_init_queue(master);
1486 dev_err(&master->dev, "problem initializing queue\n");
1487 goto err_init_queue;
1489 master->queued = true;
1490 ret = spi_start_queue(master);
1492 dev_err(&master->dev, "problem starting queue\n");
1493 goto err_start_queue;
1499 spi_destroy_queue(master);
1504 /*-------------------------------------------------------------------------*/
1506 #if defined(CONFIG_OF)
1507 static struct spi_device *
1508 of_register_spi_device(struct spi_master *master, struct device_node *nc)
1510 struct spi_device *spi;
1514 /* Alloc an spi_device */
1515 spi = spi_alloc_device(master);
1517 dev_err(&master->dev, "spi_device alloc error for %s\n",
1523 /* Select device driver */
1524 rc = of_modalias_node(nc, spi->modalias,
1525 sizeof(spi->modalias));
1527 dev_err(&master->dev, "cannot find modalias for %s\n",
1532 /* Device address */
1533 rc = of_property_read_u32(nc, "reg", &value);
1535 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1539 spi->chip_select = value;
1541 /* Mode (clock phase/polarity/etc.) */
1542 if (of_find_property(nc, "spi-cpha", NULL))
1543 spi->mode |= SPI_CPHA;
1544 if (of_find_property(nc, "spi-cpol", NULL))
1545 spi->mode |= SPI_CPOL;
1546 if (of_find_property(nc, "spi-cs-high", NULL))
1547 spi->mode |= SPI_CS_HIGH;
1548 if (of_find_property(nc, "spi-3wire", NULL))
1549 spi->mode |= SPI_3WIRE;
1550 if (of_find_property(nc, "spi-lsb-first", NULL))
1551 spi->mode |= SPI_LSB_FIRST;
1553 /* Device DUAL/QUAD mode */
1554 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1559 spi->mode |= SPI_TX_DUAL;
1562 spi->mode |= SPI_TX_QUAD;
1565 dev_warn(&master->dev,
1566 "spi-tx-bus-width %d not supported\n",
1572 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1577 spi->mode |= SPI_RX_DUAL;
1580 spi->mode |= SPI_RX_QUAD;
1583 dev_warn(&master->dev,
1584 "spi-rx-bus-width %d not supported\n",
1591 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1593 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1597 spi->max_speed_hz = value;
1599 /* Store a pointer to the node in the device structure */
1601 spi->dev.of_node = nc;
1603 /* Register the new device */
1604 rc = spi_add_device(spi);
1606 dev_err(&master->dev, "spi_device register error %s\n",
1608 goto err_of_node_put;
1621 * of_register_spi_devices() - Register child devices onto the SPI bus
1622 * @master: Pointer to spi_master device
1624 * Registers an spi_device for each child node of master node which has a 'reg'
1627 static void of_register_spi_devices(struct spi_master *master)
1629 struct spi_device *spi;
1630 struct device_node *nc;
1632 if (!master->dev.of_node)
1635 for_each_available_child_of_node(master->dev.of_node, nc) {
1636 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1638 spi = of_register_spi_device(master, nc);
1640 dev_warn(&master->dev, "Failed to create SPI device for %s\n",
1642 of_node_clear_flag(nc, OF_POPULATED);
1647 static void of_register_spi_devices(struct spi_master *master) { }
1651 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1653 struct spi_device *spi = data;
1654 struct spi_master *master = spi->master;
1656 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1657 struct acpi_resource_spi_serialbus *sb;
1659 sb = &ares->data.spi_serial_bus;
1660 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1662 * ACPI DeviceSelection numbering is handled by the
1663 * host controller driver in Windows and can vary
1664 * from driver to driver. In Linux we always expect
1665 * 0 .. max - 1 so we need to ask the driver to
1666 * translate between the two schemes.
1668 if (master->fw_translate_cs) {
1669 int cs = master->fw_translate_cs(master,
1670 sb->device_selection);
1673 spi->chip_select = cs;
1675 spi->chip_select = sb->device_selection;
1678 spi->max_speed_hz = sb->connection_speed;
1680 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1681 spi->mode |= SPI_CPHA;
1682 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1683 spi->mode |= SPI_CPOL;
1684 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1685 spi->mode |= SPI_CS_HIGH;
1687 } else if (spi->irq < 0) {
1690 if (acpi_dev_resource_interrupt(ares, 0, &r))
1694 /* Always tell the ACPI core to skip this resource */
1698 static acpi_status acpi_register_spi_device(struct spi_master *master,
1699 struct acpi_device *adev)
1701 struct list_head resource_list;
1702 struct spi_device *spi;
1705 if (acpi_bus_get_status(adev) || !adev->status.present ||
1706 acpi_device_enumerated(adev))
1709 spi = spi_alloc_device(master);
1711 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1712 dev_name(&adev->dev));
1713 return AE_NO_MEMORY;
1716 ACPI_COMPANION_SET(&spi->dev, adev);
1719 INIT_LIST_HEAD(&resource_list);
1720 ret = acpi_dev_get_resources(adev, &resource_list,
1721 acpi_spi_add_resource, spi);
1722 acpi_dev_free_resource_list(&resource_list);
1724 if (ret < 0 || !spi->max_speed_hz) {
1730 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1732 acpi_device_set_enumerated(adev);
1734 adev->power.flags.ignore_parent = true;
1735 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
1736 if (spi_add_device(spi)) {
1737 adev->power.flags.ignore_parent = false;
1738 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1739 dev_name(&adev->dev));
1746 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1747 void *data, void **return_value)
1749 struct spi_master *master = data;
1750 struct acpi_device *adev;
1752 if (acpi_bus_get_device(handle, &adev))
1755 return acpi_register_spi_device(master, adev);
1758 static void acpi_register_spi_devices(struct spi_master *master)
1763 handle = ACPI_HANDLE(master->dev.parent);
1767 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1768 acpi_spi_add_device, NULL,
1770 if (ACPI_FAILURE(status))
1771 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1774 static inline void acpi_register_spi_devices(struct spi_master *master) {}
1775 #endif /* CONFIG_ACPI */
1777 static void spi_master_release(struct device *dev)
1779 struct spi_master *master;
1781 master = container_of(dev, struct spi_master, dev);
1785 static struct class spi_master_class = {
1786 .name = "spi_master",
1787 .owner = THIS_MODULE,
1788 .dev_release = spi_master_release,
1789 .dev_groups = spi_master_groups,
1794 * spi_alloc_master - allocate SPI master controller
1795 * @dev: the controller, possibly using the platform_bus
1796 * @size: how much zeroed driver-private data to allocate; the pointer to this
1797 * memory is in the driver_data field of the returned device,
1798 * accessible with spi_master_get_devdata().
1799 * Context: can sleep
1801 * This call is used only by SPI master controller drivers, which are the
1802 * only ones directly touching chip registers. It's how they allocate
1803 * an spi_master structure, prior to calling spi_register_master().
1805 * This must be called from context that can sleep.
1807 * The caller is responsible for assigning the bus number and initializing
1808 * the master's methods before calling spi_register_master(); and (after errors
1809 * adding the device) calling spi_master_put() to prevent a memory leak.
1811 * Return: the SPI master structure on success, else NULL.
1813 struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
1815 struct spi_master *master;
1820 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
1824 device_initialize(&master->dev);
1825 master->bus_num = -1;
1826 master->num_chipselect = 1;
1827 master->dev.class = &spi_master_class;
1828 master->dev.parent = dev;
1829 pm_suspend_ignore_children(&master->dev, true);
1830 spi_master_set_devdata(master, &master[1]);
1834 EXPORT_SYMBOL_GPL(spi_alloc_master);
1837 static int of_spi_register_master(struct spi_master *master)
1840 struct device_node *np = master->dev.of_node;
1845 nb = of_gpio_named_count(np, "cs-gpios");
1846 master->num_chipselect = max_t(int, nb, master->num_chipselect);
1848 /* Return error only for an incorrectly formed cs-gpios property */
1849 if (nb == 0 || nb == -ENOENT)
1854 cs = devm_kzalloc(&master->dev,
1855 sizeof(int) * master->num_chipselect,
1857 master->cs_gpios = cs;
1859 if (!master->cs_gpios)
1862 for (i = 0; i < master->num_chipselect; i++)
1865 for (i = 0; i < nb; i++)
1866 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1871 static int of_spi_register_master(struct spi_master *master)
1878 * spi_register_master - register SPI master controller
1879 * @master: initialized master, originally from spi_alloc_master()
1880 * Context: can sleep
1882 * SPI master controllers connect to their drivers using some non-SPI bus,
1883 * such as the platform bus. The final stage of probe() in that code
1884 * includes calling spi_register_master() to hook up to this SPI bus glue.
1886 * SPI controllers use board specific (often SOC specific) bus numbers,
1887 * and board-specific addressing for SPI devices combines those numbers
1888 * with chip select numbers. Since SPI does not directly support dynamic
1889 * device identification, boards need configuration tables telling which
1890 * chip is at which address.
1892 * This must be called from context that can sleep. It returns zero on
1893 * success, else a negative error code (dropping the master's refcount).
1894 * After a successful return, the caller is responsible for calling
1895 * spi_unregister_master().
1897 * Return: zero on success, else a negative error code.
1899 int spi_register_master(struct spi_master *master)
1901 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
1902 struct device *dev = master->dev.parent;
1903 struct boardinfo *bi;
1904 int status = -ENODEV;
1910 status = of_spi_register_master(master);
1914 /* even if it's just one always-selected device, there must
1915 * be at least one chipselect
1917 if (master->num_chipselect == 0)
1920 if ((master->bus_num < 0) && master->dev.of_node)
1921 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1923 /* convention: dynamically assigned bus IDs count down from the max */
1924 if (master->bus_num < 0) {
1925 /* FIXME switch to an IDR based scheme, something like
1926 * I2C now uses, so we can't run out of "dynamic" IDs
1928 master->bus_num = atomic_dec_return(&dyn_bus_id);
1932 INIT_LIST_HEAD(&master->queue);
1933 spin_lock_init(&master->queue_lock);
1934 spin_lock_init(&master->bus_lock_spinlock);
1935 mutex_init(&master->bus_lock_mutex);
1936 mutex_init(&master->io_mutex);
1937 master->bus_lock_flag = 0;
1938 init_completion(&master->xfer_completion);
1939 if (!master->max_dma_len)
1940 master->max_dma_len = INT_MAX;
1942 /* register the device, then userspace will see it.
1943 * registration fails if the bus ID is in use.
1945 dev_set_name(&master->dev, "spi%u", master->bus_num);
1946 status = device_add(&master->dev);
1949 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
1950 dynamic ? " (dynamic)" : "");
1952 /* If we're using a queued driver, start the queue */
1953 if (master->transfer)
1954 dev_info(dev, "master is unqueued, this is deprecated\n");
1956 status = spi_master_initialize_queue(master);
1958 device_del(&master->dev);
1962 /* add statistics */
1963 spin_lock_init(&master->statistics.lock);
1965 mutex_lock(&board_lock);
1966 list_add_tail(&master->list, &spi_master_list);
1967 list_for_each_entry(bi, &board_list, list)
1968 spi_match_master_to_boardinfo(master, &bi->board_info);
1969 mutex_unlock(&board_lock);
1971 /* Register devices from the device tree and ACPI */
1972 of_register_spi_devices(master);
1973 acpi_register_spi_devices(master);
1977 EXPORT_SYMBOL_GPL(spi_register_master);
1979 static void devm_spi_unregister(struct device *dev, void *res)
1981 spi_unregister_master(*(struct spi_master **)res);
1985 * dev_spi_register_master - register managed SPI master controller
1986 * @dev: device managing SPI master
1987 * @master: initialized master, originally from spi_alloc_master()
1988 * Context: can sleep
1990 * Register a SPI device as with spi_register_master() which will
1991 * automatically be unregister
1993 * Return: zero on success, else a negative error code.
1995 int devm_spi_register_master(struct device *dev, struct spi_master *master)
1997 struct spi_master **ptr;
2000 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2004 ret = spi_register_master(master);
2007 devres_add(dev, ptr);
2014 EXPORT_SYMBOL_GPL(devm_spi_register_master);
2016 static int __unregister(struct device *dev, void *null)
2018 spi_unregister_device(to_spi_device(dev));
2023 * spi_unregister_master - unregister SPI master controller
2024 * @master: the master being unregistered
2025 * Context: can sleep
2027 * This call is used only by SPI master controller drivers, which are the
2028 * only ones directly touching chip registers.
2030 * This must be called from context that can sleep.
2032 void spi_unregister_master(struct spi_master *master)
2036 if (master->queued) {
2037 if (spi_destroy_queue(master))
2038 dev_err(&master->dev, "queue remove failed\n");
2041 mutex_lock(&board_lock);
2042 list_del(&master->list);
2043 mutex_unlock(&board_lock);
2045 dummy = device_for_each_child(&master->dev, NULL, __unregister);
2046 device_unregister(&master->dev);
2048 EXPORT_SYMBOL_GPL(spi_unregister_master);
2050 int spi_master_suspend(struct spi_master *master)
2054 /* Basically no-ops for non-queued masters */
2055 if (!master->queued)
2058 ret = spi_stop_queue(master);
2060 dev_err(&master->dev, "queue stop failed\n");
2064 EXPORT_SYMBOL_GPL(spi_master_suspend);
2066 int spi_master_resume(struct spi_master *master)
2070 if (!master->queued)
2073 ret = spi_start_queue(master);
2075 dev_err(&master->dev, "queue restart failed\n");
2079 EXPORT_SYMBOL_GPL(spi_master_resume);
2081 static int __spi_master_match(struct device *dev, const void *data)
2083 struct spi_master *m;
2084 const u16 *bus_num = data;
2086 m = container_of(dev, struct spi_master, dev);
2087 return m->bus_num == *bus_num;
2091 * spi_busnum_to_master - look up master associated with bus_num
2092 * @bus_num: the master's bus number
2093 * Context: can sleep
2095 * This call may be used with devices that are registered after
2096 * arch init time. It returns a refcounted pointer to the relevant
2097 * spi_master (which the caller must release), or NULL if there is
2098 * no such master registered.
2100 * Return: the SPI master structure on success, else NULL.
2102 struct spi_master *spi_busnum_to_master(u16 bus_num)
2105 struct spi_master *master = NULL;
2107 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2108 __spi_master_match);
2110 master = container_of(dev, struct spi_master, dev);
2111 /* reference got in class_find_device */
2114 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2116 /*-------------------------------------------------------------------------*/
2118 /* Core methods for SPI resource management */
2121 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2122 * during the processing of a spi_message while using
2124 * @spi: the spi device for which we allocate memory
2125 * @release: the release code to execute for this resource
2126 * @size: size to alloc and return
2127 * @gfp: GFP allocation flags
2129 * Return: the pointer to the allocated data
2131 * This may get enhanced in the future to allocate from a memory pool
2132 * of the @spi_device or @spi_master to avoid repeated allocations.
2134 void *spi_res_alloc(struct spi_device *spi,
2135 spi_res_release_t release,
2136 size_t size, gfp_t gfp)
2138 struct spi_res *sres;
2140 sres = kzalloc(sizeof(*sres) + size, gfp);
2144 INIT_LIST_HEAD(&sres->entry);
2145 sres->release = release;
2149 EXPORT_SYMBOL_GPL(spi_res_alloc);
2152 * spi_res_free - free an spi resource
2153 * @res: pointer to the custom data of a resource
2156 void spi_res_free(void *res)
2158 struct spi_res *sres = container_of(res, struct spi_res, data);
2163 WARN_ON(!list_empty(&sres->entry));
2166 EXPORT_SYMBOL_GPL(spi_res_free);
2169 * spi_res_add - add a spi_res to the spi_message
2170 * @message: the spi message
2171 * @res: the spi_resource
2173 void spi_res_add(struct spi_message *message, void *res)
2175 struct spi_res *sres = container_of(res, struct spi_res, data);
2177 WARN_ON(!list_empty(&sres->entry));
2178 list_add_tail(&sres->entry, &message->resources);
2180 EXPORT_SYMBOL_GPL(spi_res_add);
2183 * spi_res_release - release all spi resources for this message
2184 * @master: the @spi_master
2185 * @message: the @spi_message
2187 void spi_res_release(struct spi_master *master,
2188 struct spi_message *message)
2190 struct spi_res *res;
2192 while (!list_empty(&message->resources)) {
2193 res = list_last_entry(&message->resources,
2194 struct spi_res, entry);
2197 res->release(master, message, res->data);
2199 list_del(&res->entry);
2204 EXPORT_SYMBOL_GPL(spi_res_release);
2206 /*-------------------------------------------------------------------------*/
2208 /* Core methods for spi_message alterations */
2210 static void __spi_replace_transfers_release(struct spi_master *master,
2211 struct spi_message *msg,
2214 struct spi_replaced_transfers *rxfer = res;
2217 /* call extra callback if requested */
2219 rxfer->release(master, msg, res);
2221 /* insert replaced transfers back into the message */
2222 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2224 /* remove the formerly inserted entries */
2225 for (i = 0; i < rxfer->inserted; i++)
2226 list_del(&rxfer->inserted_transfers[i].transfer_list);
2230 * spi_replace_transfers - replace transfers with several transfers
2231 * and register change with spi_message.resources
2232 * @msg: the spi_message we work upon
2233 * @xfer_first: the first spi_transfer we want to replace
2234 * @remove: number of transfers to remove
2235 * @insert: the number of transfers we want to insert instead
2236 * @release: extra release code necessary in some circumstances
2237 * @extradatasize: extra data to allocate (with alignment guarantees
2238 * of struct @spi_transfer)
2241 * Returns: pointer to @spi_replaced_transfers,
2242 * PTR_ERR(...) in case of errors.
2244 struct spi_replaced_transfers *spi_replace_transfers(
2245 struct spi_message *msg,
2246 struct spi_transfer *xfer_first,
2249 spi_replaced_release_t release,
2250 size_t extradatasize,
2253 struct spi_replaced_transfers *rxfer;
2254 struct spi_transfer *xfer;
2257 /* allocate the structure using spi_res */
2258 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2259 insert * sizeof(struct spi_transfer)
2260 + sizeof(struct spi_replaced_transfers)
2264 return ERR_PTR(-ENOMEM);
2266 /* the release code to invoke before running the generic release */
2267 rxfer->release = release;
2269 /* assign extradata */
2272 &rxfer->inserted_transfers[insert];
2274 /* init the replaced_transfers list */
2275 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2277 /* assign the list_entry after which we should reinsert
2278 * the @replaced_transfers - it may be spi_message.messages!
2280 rxfer->replaced_after = xfer_first->transfer_list.prev;
2282 /* remove the requested number of transfers */
2283 for (i = 0; i < remove; i++) {
2284 /* if the entry after replaced_after it is msg->transfers
2285 * then we have been requested to remove more transfers
2286 * than are in the list
2288 if (rxfer->replaced_after->next == &msg->transfers) {
2289 dev_err(&msg->spi->dev,
2290 "requested to remove more spi_transfers than are available\n");
2291 /* insert replaced transfers back into the message */
2292 list_splice(&rxfer->replaced_transfers,
2293 rxfer->replaced_after);
2295 /* free the spi_replace_transfer structure */
2296 spi_res_free(rxfer);
2298 /* and return with an error */
2299 return ERR_PTR(-EINVAL);
2302 /* remove the entry after replaced_after from list of
2303 * transfers and add it to list of replaced_transfers
2305 list_move_tail(rxfer->replaced_after->next,
2306 &rxfer->replaced_transfers);
2309 /* create copy of the given xfer with identical settings
2310 * based on the first transfer to get removed
2312 for (i = 0; i < insert; i++) {
2313 /* we need to run in reverse order */
2314 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2316 /* copy all spi_transfer data */
2317 memcpy(xfer, xfer_first, sizeof(*xfer));
2320 list_add(&xfer->transfer_list, rxfer->replaced_after);
2322 /* clear cs_change and delay_usecs for all but the last */
2324 xfer->cs_change = false;
2325 xfer->delay_usecs = 0;
2329 /* set up inserted */
2330 rxfer->inserted = insert;
2332 /* and register it with spi_res/spi_message */
2333 spi_res_add(msg, rxfer);
2337 EXPORT_SYMBOL_GPL(spi_replace_transfers);
2339 static int __spi_split_transfer_maxsize(struct spi_master *master,
2340 struct spi_message *msg,
2341 struct spi_transfer **xferp,
2345 struct spi_transfer *xfer = *xferp, *xfers;
2346 struct spi_replaced_transfers *srt;
2350 /* warn once about this fact that we are splitting a transfer */
2351 dev_warn_once(&msg->spi->dev,
2352 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2353 xfer->len, maxsize);
2355 /* calculate how many we have to replace */
2356 count = DIV_ROUND_UP(xfer->len, maxsize);
2358 /* create replacement */
2359 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
2361 return PTR_ERR(srt);
2362 xfers = srt->inserted_transfers;
2364 /* now handle each of those newly inserted spi_transfers
2365 * note that the replacements spi_transfers all are preset
2366 * to the same values as *xferp, so tx_buf, rx_buf and len
2367 * are all identical (as well as most others)
2368 * so we just have to fix up len and the pointers.
2370 * this also includes support for the depreciated
2371 * spi_message.is_dma_mapped interface
2374 /* the first transfer just needs the length modified, so we
2375 * run it outside the loop
2377 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
2379 /* all the others need rx_buf/tx_buf also set */
2380 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2381 /* update rx_buf, tx_buf and dma */
2382 if (xfers[i].rx_buf)
2383 xfers[i].rx_buf += offset;
2384 if (xfers[i].rx_dma)
2385 xfers[i].rx_dma += offset;
2386 if (xfers[i].tx_buf)
2387 xfers[i].tx_buf += offset;
2388 if (xfers[i].tx_dma)
2389 xfers[i].tx_dma += offset;
2392 xfers[i].len = min(maxsize, xfers[i].len - offset);
2395 /* we set up xferp to the last entry we have inserted,
2396 * so that we skip those already split transfers
2398 *xferp = &xfers[count - 1];
2400 /* increment statistics counters */
2401 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2402 transfers_split_maxsize);
2403 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2404 transfers_split_maxsize);
2410 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2411 * when an individual transfer exceeds a
2413 * @master: the @spi_master for this transfer
2414 * @msg: the @spi_message to transform
2415 * @maxsize: the maximum when to apply this
2416 * @gfp: GFP allocation flags
2418 * Return: status of transformation
2420 int spi_split_transfers_maxsize(struct spi_master *master,
2421 struct spi_message *msg,
2425 struct spi_transfer *xfer;
2428 /* iterate over the transfer_list,
2429 * but note that xfer is advanced to the last transfer inserted
2430 * to avoid checking sizes again unnecessarily (also xfer does
2431 * potentiall belong to a different list by the time the
2432 * replacement has happened
2434 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2435 if (xfer->len > maxsize) {
2436 ret = __spi_split_transfer_maxsize(
2437 master, msg, &xfer, maxsize, gfp);
2445 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2447 /*-------------------------------------------------------------------------*/
2449 /* Core methods for SPI master protocol drivers. Some of the
2450 * other core methods are currently defined as inline functions.
2453 static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2455 if (master->bits_per_word_mask) {
2456 /* Only 32 bits fit in the mask */
2457 if (bits_per_word > 32)
2459 if (!(master->bits_per_word_mask &
2460 SPI_BPW_MASK(bits_per_word)))
2468 * spi_setup - setup SPI mode and clock rate
2469 * @spi: the device whose settings are being modified
2470 * Context: can sleep, and no requests are queued to the device
2472 * SPI protocol drivers may need to update the transfer mode if the
2473 * device doesn't work with its default. They may likewise need
2474 * to update clock rates or word sizes from initial values. This function
2475 * changes those settings, and must be called from a context that can sleep.
2476 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2477 * effect the next time the device is selected and data is transferred to
2478 * or from it. When this function returns, the spi device is deselected.
2480 * Note that this call will fail if the protocol driver specifies an option
2481 * that the underlying controller or its driver does not support. For
2482 * example, not all hardware supports wire transfers using nine bit words,
2483 * LSB-first wire encoding, or active-high chipselects.
2485 * Return: zero on success, else a negative error code.
2487 int spi_setup(struct spi_device *spi)
2489 unsigned bad_bits, ugly_bits;
2492 /* check mode to prevent that DUAL and QUAD set at the same time
2494 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2495 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2497 "setup: can not select dual and quad at the same time\n");
2500 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2502 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2503 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2505 /* help drivers fail *cleanly* when they need options
2506 * that aren't supported with their current master
2508 bad_bits = spi->mode & ~spi->master->mode_bits;
2509 ugly_bits = bad_bits &
2510 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2513 "setup: ignoring unsupported mode bits %x\n",
2515 spi->mode &= ~ugly_bits;
2516 bad_bits &= ~ugly_bits;
2519 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
2524 if (!spi->bits_per_word)
2525 spi->bits_per_word = 8;
2527 status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2531 if (!spi->max_speed_hz)
2532 spi->max_speed_hz = spi->master->max_speed_hz;
2534 if (spi->master->setup)
2535 status = spi->master->setup(spi);
2537 spi_set_cs(spi, false);
2539 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2540 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2541 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2542 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2543 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2544 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2545 spi->bits_per_word, spi->max_speed_hz,
2550 EXPORT_SYMBOL_GPL(spi_setup);
2552 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
2554 struct spi_master *master = spi->master;
2555 struct spi_transfer *xfer;
2558 if (list_empty(&message->transfers))
2561 /* Half-duplex links include original MicroWire, and ones with
2562 * only one data pin like SPI_3WIRE (switches direction) or where
2563 * either MOSI or MISO is missing. They can also be caused by
2564 * software limitations.
2566 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2567 || (spi->mode & SPI_3WIRE)) {
2568 unsigned flags = master->flags;
2570 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2571 if (xfer->rx_buf && xfer->tx_buf)
2573 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2575 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2581 * Set transfer bits_per_word and max speed as spi device default if
2582 * it is not set for this transfer.
2583 * Set transfer tx_nbits and rx_nbits as single transfer default
2584 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2586 message->frame_length = 0;
2587 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2588 message->frame_length += xfer->len;
2589 if (!xfer->bits_per_word)
2590 xfer->bits_per_word = spi->bits_per_word;
2592 if (!xfer->speed_hz)
2593 xfer->speed_hz = spi->max_speed_hz;
2594 if (!xfer->speed_hz)
2595 xfer->speed_hz = master->max_speed_hz;
2597 if (master->max_speed_hz &&
2598 xfer->speed_hz > master->max_speed_hz)
2599 xfer->speed_hz = master->max_speed_hz;
2601 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2605 * SPI transfer length should be multiple of SPI word size
2606 * where SPI word size should be power-of-two multiple
2608 if (xfer->bits_per_word <= 8)
2610 else if (xfer->bits_per_word <= 16)
2615 /* No partial transfers accepted */
2616 if (xfer->len % w_size)
2619 if (xfer->speed_hz && master->min_speed_hz &&
2620 xfer->speed_hz < master->min_speed_hz)
2623 if (xfer->tx_buf && !xfer->tx_nbits)
2624 xfer->tx_nbits = SPI_NBITS_SINGLE;
2625 if (xfer->rx_buf && !xfer->rx_nbits)
2626 xfer->rx_nbits = SPI_NBITS_SINGLE;
2627 /* check transfer tx/rx_nbits:
2628 * 1. check the value matches one of single, dual and quad
2629 * 2. check tx/rx_nbits match the mode in spi_device
2632 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2633 xfer->tx_nbits != SPI_NBITS_DUAL &&
2634 xfer->tx_nbits != SPI_NBITS_QUAD)
2636 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2637 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2639 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2640 !(spi->mode & SPI_TX_QUAD))
2643 /* check transfer rx_nbits */
2645 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2646 xfer->rx_nbits != SPI_NBITS_DUAL &&
2647 xfer->rx_nbits != SPI_NBITS_QUAD)
2649 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2650 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2652 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2653 !(spi->mode & SPI_RX_QUAD))
2658 message->status = -EINPROGRESS;
2663 static int __spi_async(struct spi_device *spi, struct spi_message *message)
2665 struct spi_master *master = spi->master;
2669 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2670 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2672 trace_spi_message_submit(message);
2674 return master->transfer(spi, message);
2678 * spi_async - asynchronous SPI transfer
2679 * @spi: device with which data will be exchanged
2680 * @message: describes the data transfers, including completion callback
2681 * Context: any (irqs may be blocked, etc)
2683 * This call may be used in_irq and other contexts which can't sleep,
2684 * as well as from task contexts which can sleep.
2686 * The completion callback is invoked in a context which can't sleep.
2687 * Before that invocation, the value of message->status is undefined.
2688 * When the callback is issued, message->status holds either zero (to
2689 * indicate complete success) or a negative error code. After that
2690 * callback returns, the driver which issued the transfer request may
2691 * deallocate the associated memory; it's no longer in use by any SPI
2692 * core or controller driver code.
2694 * Note that although all messages to a spi_device are handled in
2695 * FIFO order, messages may go to different devices in other orders.
2696 * Some device might be higher priority, or have various "hard" access
2697 * time requirements, for example.
2699 * On detection of any fault during the transfer, processing of
2700 * the entire message is aborted, and the device is deselected.
2701 * Until returning from the associated message completion callback,
2702 * no other spi_message queued to that device will be processed.
2703 * (This rule applies equally to all the synchronous transfer calls,
2704 * which are wrappers around this core asynchronous primitive.)
2706 * Return: zero on success, else a negative error code.
2708 int spi_async(struct spi_device *spi, struct spi_message *message)
2710 struct spi_master *master = spi->master;
2712 unsigned long flags;
2714 ret = __spi_validate(spi, message);
2718 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2720 if (master->bus_lock_flag)
2723 ret = __spi_async(spi, message);
2725 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2729 EXPORT_SYMBOL_GPL(spi_async);
2732 * spi_async_locked - version of spi_async with exclusive bus usage
2733 * @spi: device with which data will be exchanged
2734 * @message: describes the data transfers, including completion callback
2735 * Context: any (irqs may be blocked, etc)
2737 * This call may be used in_irq and other contexts which can't sleep,
2738 * as well as from task contexts which can sleep.
2740 * The completion callback is invoked in a context which can't sleep.
2741 * Before that invocation, the value of message->status is undefined.
2742 * When the callback is issued, message->status holds either zero (to
2743 * indicate complete success) or a negative error code. After that
2744 * callback returns, the driver which issued the transfer request may
2745 * deallocate the associated memory; it's no longer in use by any SPI
2746 * core or controller driver code.
2748 * Note that although all messages to a spi_device are handled in
2749 * FIFO order, messages may go to different devices in other orders.
2750 * Some device might be higher priority, or have various "hard" access
2751 * time requirements, for example.
2753 * On detection of any fault during the transfer, processing of
2754 * the entire message is aborted, and the device is deselected.
2755 * Until returning from the associated message completion callback,
2756 * no other spi_message queued to that device will be processed.
2757 * (This rule applies equally to all the synchronous transfer calls,
2758 * which are wrappers around this core asynchronous primitive.)
2760 * Return: zero on success, else a negative error code.
2762 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2764 struct spi_master *master = spi->master;
2766 unsigned long flags;
2768 ret = __spi_validate(spi, message);
2772 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2774 ret = __spi_async(spi, message);
2776 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2781 EXPORT_SYMBOL_GPL(spi_async_locked);
2784 int spi_flash_read(struct spi_device *spi,
2785 struct spi_flash_read_message *msg)
2788 struct spi_master *master = spi->master;
2789 struct device *rx_dev = NULL;
2792 if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2793 msg->addr_nbits == SPI_NBITS_DUAL) &&
2794 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2796 if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2797 msg->addr_nbits == SPI_NBITS_QUAD) &&
2798 !(spi->mode & SPI_TX_QUAD))
2800 if (msg->data_nbits == SPI_NBITS_DUAL &&
2801 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2803 if (msg->data_nbits == SPI_NBITS_QUAD &&
2804 !(spi->mode & SPI_RX_QUAD))
2807 if (master->auto_runtime_pm) {
2808 ret = pm_runtime_get_sync(master->dev.parent);
2810 dev_err(&master->dev, "Failed to power device: %d\n",
2816 mutex_lock(&master->bus_lock_mutex);
2817 mutex_lock(&master->io_mutex);
2818 if (master->dma_rx) {
2819 rx_dev = master->dma_rx->device->dev;
2820 ret = spi_map_buf(master, rx_dev, &msg->rx_sg,
2824 msg->cur_msg_mapped = true;
2826 ret = master->spi_flash_read(spi, msg);
2827 if (msg->cur_msg_mapped)
2828 spi_unmap_buf(master, rx_dev, &msg->rx_sg,
2830 mutex_unlock(&master->io_mutex);
2831 mutex_unlock(&master->bus_lock_mutex);
2833 if (master->auto_runtime_pm)
2834 pm_runtime_put(master->dev.parent);
2838 EXPORT_SYMBOL_GPL(spi_flash_read);
2840 /*-------------------------------------------------------------------------*/
2842 /* Utility methods for SPI master protocol drivers, layered on
2843 * top of the core. Some other utility methods are defined as
2847 static void spi_complete(void *arg)
2852 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
2854 DECLARE_COMPLETION_ONSTACK(done);
2856 struct spi_master *master = spi->master;
2857 unsigned long flags;
2859 status = __spi_validate(spi, message);
2863 message->complete = spi_complete;
2864 message->context = &done;
2867 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2868 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2870 /* If we're not using the legacy transfer method then we will
2871 * try to transfer in the calling context so special case.
2872 * This code would be less tricky if we could remove the
2873 * support for driver implemented message queues.
2875 if (master->transfer == spi_queued_transfer) {
2876 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2878 trace_spi_message_submit(message);
2880 status = __spi_queued_transfer(spi, message, false);
2882 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2884 status = spi_async_locked(spi, message);
2888 /* Push out the messages in the calling context if we
2891 if (master->transfer == spi_queued_transfer) {
2892 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2893 spi_sync_immediate);
2894 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
2895 spi_sync_immediate);
2896 __spi_pump_messages(master, false);
2899 wait_for_completion(&done);
2900 status = message->status;
2902 message->context = NULL;
2907 * spi_sync - blocking/synchronous SPI data transfers
2908 * @spi: device with which data will be exchanged
2909 * @message: describes the data transfers
2910 * Context: can sleep
2912 * This call may only be used from a context that may sleep. The sleep
2913 * is non-interruptible, and has no timeout. Low-overhead controller
2914 * drivers may DMA directly into and out of the message buffers.
2916 * Note that the SPI device's chip select is active during the message,
2917 * and then is normally disabled between messages. Drivers for some
2918 * frequently-used devices may want to minimize costs of selecting a chip,
2919 * by leaving it selected in anticipation that the next message will go
2920 * to the same chip. (That may increase power usage.)
2922 * Also, the caller is guaranteeing that the memory associated with the
2923 * message will not be freed before this call returns.
2925 * Return: zero on success, else a negative error code.
2927 int spi_sync(struct spi_device *spi, struct spi_message *message)
2931 mutex_lock(&spi->master->bus_lock_mutex);
2932 ret = __spi_sync(spi, message);
2933 mutex_unlock(&spi->master->bus_lock_mutex);
2937 EXPORT_SYMBOL_GPL(spi_sync);
2940 * spi_sync_locked - version of spi_sync with exclusive bus usage
2941 * @spi: device with which data will be exchanged
2942 * @message: describes the data transfers
2943 * Context: can sleep
2945 * This call may only be used from a context that may sleep. The sleep
2946 * is non-interruptible, and has no timeout. Low-overhead controller
2947 * drivers may DMA directly into and out of the message buffers.
2949 * This call should be used by drivers that require exclusive access to the
2950 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
2951 * be released by a spi_bus_unlock call when the exclusive access is over.
2953 * Return: zero on success, else a negative error code.
2955 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2957 return __spi_sync(spi, message);
2959 EXPORT_SYMBOL_GPL(spi_sync_locked);
2962 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2963 * @master: SPI bus master that should be locked for exclusive bus access
2964 * Context: can sleep
2966 * This call may only be used from a context that may sleep. The sleep
2967 * is non-interruptible, and has no timeout.
2969 * This call should be used by drivers that require exclusive access to the
2970 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2971 * exclusive access is over. Data transfer must be done by spi_sync_locked
2972 * and spi_async_locked calls when the SPI bus lock is held.
2974 * Return: always zero.
2976 int spi_bus_lock(struct spi_master *master)
2978 unsigned long flags;
2980 mutex_lock(&master->bus_lock_mutex);
2982 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2983 master->bus_lock_flag = 1;
2984 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2986 /* mutex remains locked until spi_bus_unlock is called */
2990 EXPORT_SYMBOL_GPL(spi_bus_lock);
2993 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2994 * @master: SPI bus master that was locked for exclusive bus access
2995 * Context: can sleep
2997 * This call may only be used from a context that may sleep. The sleep
2998 * is non-interruptible, and has no timeout.
3000 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3003 * Return: always zero.
3005 int spi_bus_unlock(struct spi_master *master)
3007 master->bus_lock_flag = 0;
3009 mutex_unlock(&master->bus_lock_mutex);
3013 EXPORT_SYMBOL_GPL(spi_bus_unlock);
3015 /* portable code must never pass more than 32 bytes */
3016 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3021 * spi_write_then_read - SPI synchronous write followed by read
3022 * @spi: device with which data will be exchanged
3023 * @txbuf: data to be written (need not be dma-safe)
3024 * @n_tx: size of txbuf, in bytes
3025 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3026 * @n_rx: size of rxbuf, in bytes
3027 * Context: can sleep
3029 * This performs a half duplex MicroWire style transaction with the
3030 * device, sending txbuf and then reading rxbuf. The return value
3031 * is zero for success, else a negative errno status code.
3032 * This call may only be used from a context that may sleep.
3034 * Parameters to this routine are always copied using a small buffer;
3035 * portable code should never use this for more than 32 bytes.
3036 * Performance-sensitive or bulk transfer code should instead use
3037 * spi_{async,sync}() calls with dma-safe buffers.
3039 * Return: zero on success, else a negative error code.
3041 int spi_write_then_read(struct spi_device *spi,
3042 const void *txbuf, unsigned n_tx,
3043 void *rxbuf, unsigned n_rx)
3045 static DEFINE_MUTEX(lock);
3048 struct spi_message message;
3049 struct spi_transfer x[2];
3052 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3053 * copying here, (as a pure convenience thing), but we can
3054 * keep heap costs out of the hot path unless someone else is
3055 * using the pre-allocated buffer or the transfer is too large.
3057 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
3058 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3059 GFP_KERNEL | GFP_DMA);
3066 spi_message_init(&message);
3067 memset(x, 0, sizeof(x));
3070 spi_message_add_tail(&x[0], &message);
3074 spi_message_add_tail(&x[1], &message);
3077 memcpy(local_buf, txbuf, n_tx);
3078 x[0].tx_buf = local_buf;
3079 x[1].rx_buf = local_buf + n_tx;
3082 status = spi_sync(spi, &message);
3084 memcpy(rxbuf, x[1].rx_buf, n_rx);
3086 if (x[0].tx_buf == buf)
3087 mutex_unlock(&lock);
3093 EXPORT_SYMBOL_GPL(spi_write_then_read);
3095 /*-------------------------------------------------------------------------*/
3097 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
3098 static int __spi_of_device_match(struct device *dev, void *data)
3100 return dev->of_node == data;
3103 /* must call put_device() when done with returned spi_device device */
3104 static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3106 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3107 __spi_of_device_match);
3108 return dev ? to_spi_device(dev) : NULL;
3111 static int __spi_of_master_match(struct device *dev, const void *data)
3113 return dev->of_node == data;
3116 /* the spi masters are not using spi_bus, so we find it with another way */
3117 static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3121 dev = class_find_device(&spi_master_class, NULL, node,
3122 __spi_of_master_match);
3126 /* reference got in class_find_device */
3127 return container_of(dev, struct spi_master, dev);
3130 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3133 struct of_reconfig_data *rd = arg;
3134 struct spi_master *master;
3135 struct spi_device *spi;
3137 switch (of_reconfig_get_state_change(action, arg)) {
3138 case OF_RECONFIG_CHANGE_ADD:
3139 master = of_find_spi_master_by_node(rd->dn->parent);
3141 return NOTIFY_OK; /* not for us */
3143 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3144 put_device(&master->dev);
3148 spi = of_register_spi_device(master, rd->dn);
3149 put_device(&master->dev);
3152 pr_err("%s: failed to create for '%s'\n",
3153 __func__, rd->dn->full_name);
3154 of_node_clear_flag(rd->dn, OF_POPULATED);
3155 return notifier_from_errno(PTR_ERR(spi));
3159 case OF_RECONFIG_CHANGE_REMOVE:
3160 /* already depopulated? */
3161 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3164 /* find our device by node */
3165 spi = of_find_spi_device_by_node(rd->dn);
3167 return NOTIFY_OK; /* no? not meant for us */
3169 /* unregister takes one ref away */
3170 spi_unregister_device(spi);
3172 /* and put the reference of the find */
3173 put_device(&spi->dev);
3180 static struct notifier_block spi_of_notifier = {
3181 .notifier_call = of_spi_notify,
3183 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3184 extern struct notifier_block spi_of_notifier;
3185 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3187 #if IS_ENABLED(CONFIG_ACPI)
3188 static int spi_acpi_master_match(struct device *dev, const void *data)
3190 return ACPI_COMPANION(dev->parent) == data;
3193 static int spi_acpi_device_match(struct device *dev, void *data)
3195 return ACPI_COMPANION(dev) == data;
3198 static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device *adev)
3202 dev = class_find_device(&spi_master_class, NULL, adev,
3203 spi_acpi_master_match);
3207 return container_of(dev, struct spi_master, dev);
3210 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3214 dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3216 return dev ? to_spi_device(dev) : NULL;
3219 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3222 struct acpi_device *adev = arg;
3223 struct spi_master *master;
3224 struct spi_device *spi;
3227 case ACPI_RECONFIG_DEVICE_ADD:
3228 master = acpi_spi_find_master_by_adev(adev->parent);
3232 acpi_register_spi_device(master, adev);
3233 put_device(&master->dev);
3235 case ACPI_RECONFIG_DEVICE_REMOVE:
3236 if (!acpi_device_enumerated(adev))
3239 spi = acpi_spi_find_device_by_adev(adev);
3243 spi_unregister_device(spi);
3244 put_device(&spi->dev);
3251 static struct notifier_block spi_acpi_notifier = {
3252 .notifier_call = acpi_spi_notify,
3255 extern struct notifier_block spi_acpi_notifier;
3258 static int __init spi_init(void)
3262 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
3268 status = bus_register(&spi_bus_type);
3272 status = class_register(&spi_master_class);
3276 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
3277 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3278 if (IS_ENABLED(CONFIG_ACPI))
3279 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
3284 bus_unregister(&spi_bus_type);
3292 /* board_info is normally registered in arch_initcall(),
3293 * but even essential drivers wait till later
3295 * REVISIT only boardinfo really needs static linking. the rest (device and
3296 * driver registration) _could_ be dynamically linked (modular) ... costs
3297 * include needing to have boardinfo data structures be much more public.
3299 postcore_initcall(spi_init);