1 // SPDX-License-Identifier: GPL-2.0-or-later
4 // Copyright (C) 2005 David Brownell
5 // Copyright (C) 2008 Secret Lab Technologies Ltd.
7 #include <linux/kernel.h>
8 #include <linux/device.h>
9 #include <linux/init.h>
10 #include <linux/cache.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/dmaengine.h>
13 #include <linux/mutex.h>
14 #include <linux/of_device.h>
15 #include <linux/of_irq.h>
16 #include <linux/clk/clk-conf.h>
17 #include <linux/slab.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/spi/spi.h>
20 #include <linux/spi/spi-mem.h>
21 #include <linux/of_gpio.h>
22 #include <linux/gpio/consumer.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/pm_domain.h>
25 #include <linux/property.h>
26 #include <linux/export.h>
27 #include <linux/sched/rt.h>
28 #include <uapi/linux/sched/types.h>
29 #include <linux/delay.h>
30 #include <linux/kthread.h>
31 #include <linux/ioport.h>
32 #include <linux/acpi.h>
33 #include <linux/highmem.h>
34 #include <linux/idr.h>
35 #include <linux/platform_data/x86/apple.h>
37 #define CREATE_TRACE_POINTS
38 #include <trace/events/spi.h>
39 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start
);
40 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop
);
42 #include "internals.h"
44 static DEFINE_IDR(spi_master_idr
);
46 static void spidev_release(struct device
*dev
)
48 struct spi_device
*spi
= to_spi_device(dev
);
50 /* spi controllers may cleanup for released devices */
51 if (spi
->controller
->cleanup
)
52 spi
->controller
->cleanup(spi
);
54 spi_controller_put(spi
->controller
);
55 kfree(spi
->driver_override
);
60 modalias_show(struct device
*dev
, struct device_attribute
*a
, char *buf
)
62 const struct spi_device
*spi
= to_spi_device(dev
);
65 len
= acpi_device_modalias(dev
, buf
, PAGE_SIZE
- 1);
69 return sprintf(buf
, "%s%s\n", SPI_MODULE_PREFIX
, spi
->modalias
);
71 static DEVICE_ATTR_RO(modalias
);
73 static ssize_t
driver_override_store(struct device
*dev
,
74 struct device_attribute
*a
,
75 const char *buf
, size_t count
)
77 struct spi_device
*spi
= to_spi_device(dev
);
78 const char *end
= memchr(buf
, '\n', count
);
79 const size_t len
= end
? end
- buf
: count
;
80 const char *driver_override
, *old
;
82 /* We need to keep extra room for a newline when displaying value */
83 if (len
>= (PAGE_SIZE
- 1))
86 driver_override
= kstrndup(buf
, len
, GFP_KERNEL
);
91 old
= spi
->driver_override
;
93 spi
->driver_override
= driver_override
;
95 /* Emptry string, disable driver override */
96 spi
->driver_override
= NULL
;
97 kfree(driver_override
);
105 static ssize_t
driver_override_show(struct device
*dev
,
106 struct device_attribute
*a
, char *buf
)
108 const struct spi_device
*spi
= to_spi_device(dev
);
112 len
= snprintf(buf
, PAGE_SIZE
, "%s\n", spi
->driver_override
? : "");
116 static DEVICE_ATTR_RW(driver_override
);
118 #define SPI_STATISTICS_ATTRS(field, file) \
119 static ssize_t spi_controller_##field##_show(struct device *dev, \
120 struct device_attribute *attr, \
123 struct spi_controller *ctlr = container_of(dev, \
124 struct spi_controller, dev); \
125 return spi_statistics_##field##_show(&ctlr->statistics, buf); \
127 static struct device_attribute dev_attr_spi_controller_##field = { \
128 .attr = { .name = file, .mode = 0444 }, \
129 .show = spi_controller_##field##_show, \
131 static ssize_t spi_device_##field##_show(struct device *dev, \
132 struct device_attribute *attr, \
135 struct spi_device *spi = to_spi_device(dev); \
136 return spi_statistics_##field##_show(&spi->statistics, buf); \
138 static struct device_attribute dev_attr_spi_device_##field = { \
139 .attr = { .name = file, .mode = 0444 }, \
140 .show = spi_device_##field##_show, \
143 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
144 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
147 unsigned long flags; \
149 spin_lock_irqsave(&stat->lock, flags); \
150 len = sprintf(buf, format_string, stat->field); \
151 spin_unlock_irqrestore(&stat->lock, flags); \
154 SPI_STATISTICS_ATTRS(name, file)
156 #define SPI_STATISTICS_SHOW(field, format_string) \
157 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
158 field, format_string)
160 SPI_STATISTICS_SHOW(messages
, "%lu");
161 SPI_STATISTICS_SHOW(transfers
, "%lu");
162 SPI_STATISTICS_SHOW(errors
, "%lu");
163 SPI_STATISTICS_SHOW(timedout
, "%lu");
165 SPI_STATISTICS_SHOW(spi_sync
, "%lu");
166 SPI_STATISTICS_SHOW(spi_sync_immediate
, "%lu");
167 SPI_STATISTICS_SHOW(spi_async
, "%lu");
169 SPI_STATISTICS_SHOW(bytes
, "%llu");
170 SPI_STATISTICS_SHOW(bytes_rx
, "%llu");
171 SPI_STATISTICS_SHOW(bytes_tx
, "%llu");
173 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
174 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
175 "transfer_bytes_histo_" number, \
176 transfer_bytes_histo[index], "%lu")
177 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
178 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
179 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
180 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
181 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
182 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
183 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
184 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
185 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
186 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
187 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
188 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
189 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
190 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
191 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
192 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
193 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
195 SPI_STATISTICS_SHOW(transfers_split_maxsize
, "%lu");
197 static struct attribute
*spi_dev_attrs
[] = {
198 &dev_attr_modalias
.attr
,
199 &dev_attr_driver_override
.attr
,
203 static const struct attribute_group spi_dev_group
= {
204 .attrs
= spi_dev_attrs
,
207 static struct attribute
*spi_device_statistics_attrs
[] = {
208 &dev_attr_spi_device_messages
.attr
,
209 &dev_attr_spi_device_transfers
.attr
,
210 &dev_attr_spi_device_errors
.attr
,
211 &dev_attr_spi_device_timedout
.attr
,
212 &dev_attr_spi_device_spi_sync
.attr
,
213 &dev_attr_spi_device_spi_sync_immediate
.attr
,
214 &dev_attr_spi_device_spi_async
.attr
,
215 &dev_attr_spi_device_bytes
.attr
,
216 &dev_attr_spi_device_bytes_rx
.attr
,
217 &dev_attr_spi_device_bytes_tx
.attr
,
218 &dev_attr_spi_device_transfer_bytes_histo0
.attr
,
219 &dev_attr_spi_device_transfer_bytes_histo1
.attr
,
220 &dev_attr_spi_device_transfer_bytes_histo2
.attr
,
221 &dev_attr_spi_device_transfer_bytes_histo3
.attr
,
222 &dev_attr_spi_device_transfer_bytes_histo4
.attr
,
223 &dev_attr_spi_device_transfer_bytes_histo5
.attr
,
224 &dev_attr_spi_device_transfer_bytes_histo6
.attr
,
225 &dev_attr_spi_device_transfer_bytes_histo7
.attr
,
226 &dev_attr_spi_device_transfer_bytes_histo8
.attr
,
227 &dev_attr_spi_device_transfer_bytes_histo9
.attr
,
228 &dev_attr_spi_device_transfer_bytes_histo10
.attr
,
229 &dev_attr_spi_device_transfer_bytes_histo11
.attr
,
230 &dev_attr_spi_device_transfer_bytes_histo12
.attr
,
231 &dev_attr_spi_device_transfer_bytes_histo13
.attr
,
232 &dev_attr_spi_device_transfer_bytes_histo14
.attr
,
233 &dev_attr_spi_device_transfer_bytes_histo15
.attr
,
234 &dev_attr_spi_device_transfer_bytes_histo16
.attr
,
235 &dev_attr_spi_device_transfers_split_maxsize
.attr
,
239 static const struct attribute_group spi_device_statistics_group
= {
240 .name
= "statistics",
241 .attrs
= spi_device_statistics_attrs
,
244 static const struct attribute_group
*spi_dev_groups
[] = {
246 &spi_device_statistics_group
,
250 static struct attribute
*spi_controller_statistics_attrs
[] = {
251 &dev_attr_spi_controller_messages
.attr
,
252 &dev_attr_spi_controller_transfers
.attr
,
253 &dev_attr_spi_controller_errors
.attr
,
254 &dev_attr_spi_controller_timedout
.attr
,
255 &dev_attr_spi_controller_spi_sync
.attr
,
256 &dev_attr_spi_controller_spi_sync_immediate
.attr
,
257 &dev_attr_spi_controller_spi_async
.attr
,
258 &dev_attr_spi_controller_bytes
.attr
,
259 &dev_attr_spi_controller_bytes_rx
.attr
,
260 &dev_attr_spi_controller_bytes_tx
.attr
,
261 &dev_attr_spi_controller_transfer_bytes_histo0
.attr
,
262 &dev_attr_spi_controller_transfer_bytes_histo1
.attr
,
263 &dev_attr_spi_controller_transfer_bytes_histo2
.attr
,
264 &dev_attr_spi_controller_transfer_bytes_histo3
.attr
,
265 &dev_attr_spi_controller_transfer_bytes_histo4
.attr
,
266 &dev_attr_spi_controller_transfer_bytes_histo5
.attr
,
267 &dev_attr_spi_controller_transfer_bytes_histo6
.attr
,
268 &dev_attr_spi_controller_transfer_bytes_histo7
.attr
,
269 &dev_attr_spi_controller_transfer_bytes_histo8
.attr
,
270 &dev_attr_spi_controller_transfer_bytes_histo9
.attr
,
271 &dev_attr_spi_controller_transfer_bytes_histo10
.attr
,
272 &dev_attr_spi_controller_transfer_bytes_histo11
.attr
,
273 &dev_attr_spi_controller_transfer_bytes_histo12
.attr
,
274 &dev_attr_spi_controller_transfer_bytes_histo13
.attr
,
275 &dev_attr_spi_controller_transfer_bytes_histo14
.attr
,
276 &dev_attr_spi_controller_transfer_bytes_histo15
.attr
,
277 &dev_attr_spi_controller_transfer_bytes_histo16
.attr
,
278 &dev_attr_spi_controller_transfers_split_maxsize
.attr
,
282 static const struct attribute_group spi_controller_statistics_group
= {
283 .name
= "statistics",
284 .attrs
= spi_controller_statistics_attrs
,
287 static const struct attribute_group
*spi_master_groups
[] = {
288 &spi_controller_statistics_group
,
292 void spi_statistics_add_transfer_stats(struct spi_statistics
*stats
,
293 struct spi_transfer
*xfer
,
294 struct spi_controller
*ctlr
)
297 int l2len
= min(fls(xfer
->len
), SPI_STATISTICS_HISTO_SIZE
) - 1;
302 spin_lock_irqsave(&stats
->lock
, flags
);
305 stats
->transfer_bytes_histo
[l2len
]++;
307 stats
->bytes
+= xfer
->len
;
308 if ((xfer
->tx_buf
) &&
309 (xfer
->tx_buf
!= ctlr
->dummy_tx
))
310 stats
->bytes_tx
+= xfer
->len
;
311 if ((xfer
->rx_buf
) &&
312 (xfer
->rx_buf
!= ctlr
->dummy_rx
))
313 stats
->bytes_rx
+= xfer
->len
;
315 spin_unlock_irqrestore(&stats
->lock
, flags
);
317 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats
);
319 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
320 * and the sysfs version makes coldplug work too.
323 static const struct spi_device_id
*spi_match_id(const struct spi_device_id
*id
,
324 const struct spi_device
*sdev
)
326 while (id
->name
[0]) {
327 if (!strcmp(sdev
->modalias
, id
->name
))
334 const struct spi_device_id
*spi_get_device_id(const struct spi_device
*sdev
)
336 const struct spi_driver
*sdrv
= to_spi_driver(sdev
->dev
.driver
);
338 return spi_match_id(sdrv
->id_table
, sdev
);
340 EXPORT_SYMBOL_GPL(spi_get_device_id
);
342 static int spi_match_device(struct device
*dev
, struct device_driver
*drv
)
344 const struct spi_device
*spi
= to_spi_device(dev
);
345 const struct spi_driver
*sdrv
= to_spi_driver(drv
);
347 /* Check override first, and if set, only use the named driver */
348 if (spi
->driver_override
)
349 return strcmp(spi
->driver_override
, drv
->name
) == 0;
351 /* Attempt an OF style match */
352 if (of_driver_match_device(dev
, drv
))
356 if (acpi_driver_match_device(dev
, drv
))
360 return !!spi_match_id(sdrv
->id_table
, spi
);
362 return strcmp(spi
->modalias
, drv
->name
) == 0;
365 static int spi_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
367 const struct spi_device
*spi
= to_spi_device(dev
);
370 rc
= acpi_device_uevent_modalias(dev
, env
);
374 return add_uevent_var(env
, "MODALIAS=%s%s", SPI_MODULE_PREFIX
, spi
->modalias
);
377 struct bus_type spi_bus_type
= {
379 .dev_groups
= spi_dev_groups
,
380 .match
= spi_match_device
,
381 .uevent
= spi_uevent
,
383 EXPORT_SYMBOL_GPL(spi_bus_type
);
386 static int spi_drv_probe(struct device
*dev
)
388 const struct spi_driver
*sdrv
= to_spi_driver(dev
->driver
);
389 struct spi_device
*spi
= to_spi_device(dev
);
392 ret
= of_clk_set_defaults(dev
->of_node
, false);
397 spi
->irq
= of_irq_get(dev
->of_node
, 0);
398 if (spi
->irq
== -EPROBE_DEFER
)
399 return -EPROBE_DEFER
;
404 ret
= dev_pm_domain_attach(dev
, true);
408 ret
= sdrv
->probe(spi
);
410 dev_pm_domain_detach(dev
, true);
415 static int spi_drv_remove(struct device
*dev
)
417 const struct spi_driver
*sdrv
= to_spi_driver(dev
->driver
);
420 ret
= sdrv
->remove(to_spi_device(dev
));
421 dev_pm_domain_detach(dev
, true);
426 static void spi_drv_shutdown(struct device
*dev
)
428 const struct spi_driver
*sdrv
= to_spi_driver(dev
->driver
);
430 sdrv
->shutdown(to_spi_device(dev
));
434 * __spi_register_driver - register a SPI driver
435 * @owner: owner module of the driver to register
436 * @sdrv: the driver to register
439 * Return: zero on success, else a negative error code.
441 int __spi_register_driver(struct module
*owner
, struct spi_driver
*sdrv
)
443 sdrv
->driver
.owner
= owner
;
444 sdrv
->driver
.bus
= &spi_bus_type
;
446 sdrv
->driver
.probe
= spi_drv_probe
;
448 sdrv
->driver
.remove
= spi_drv_remove
;
450 sdrv
->driver
.shutdown
= spi_drv_shutdown
;
451 return driver_register(&sdrv
->driver
);
453 EXPORT_SYMBOL_GPL(__spi_register_driver
);
455 /*-------------------------------------------------------------------------*/
457 /* SPI devices should normally not be created by SPI device drivers; that
458 * would make them board-specific. Similarly with SPI controller drivers.
459 * Device registration normally goes into like arch/.../mach.../board-YYY.c
460 * with other readonly (flashable) information about mainboard devices.
464 struct list_head list
;
465 struct spi_board_info board_info
;
468 static LIST_HEAD(board_list
);
469 static LIST_HEAD(spi_controller_list
);
472 * Used to protect add/del opertion for board_info list and
473 * spi_controller list, and their matching process
474 * also used to protect object of type struct idr
476 static DEFINE_MUTEX(board_lock
);
479 * spi_alloc_device - Allocate a new SPI device
480 * @ctlr: Controller to which device is connected
483 * Allows a driver to allocate and initialize a spi_device without
484 * registering it immediately. This allows a driver to directly
485 * fill the spi_device with device parameters before calling
486 * spi_add_device() on it.
488 * Caller is responsible to call spi_add_device() on the returned
489 * spi_device structure to add it to the SPI controller. If the caller
490 * needs to discard the spi_device without adding it, then it should
491 * call spi_dev_put() on it.
493 * Return: a pointer to the new device, or NULL.
495 struct spi_device
*spi_alloc_device(struct spi_controller
*ctlr
)
497 struct spi_device
*spi
;
499 if (!spi_controller_get(ctlr
))
502 spi
= kzalloc(sizeof(*spi
), GFP_KERNEL
);
504 spi_controller_put(ctlr
);
508 spi
->master
= spi
->controller
= ctlr
;
509 spi
->dev
.parent
= &ctlr
->dev
;
510 spi
->dev
.bus
= &spi_bus_type
;
511 spi
->dev
.release
= spidev_release
;
512 spi
->cs_gpio
= -ENOENT
;
514 spin_lock_init(&spi
->statistics
.lock
);
516 device_initialize(&spi
->dev
);
519 EXPORT_SYMBOL_GPL(spi_alloc_device
);
521 static void spi_dev_set_name(struct spi_device
*spi
)
523 struct acpi_device
*adev
= ACPI_COMPANION(&spi
->dev
);
526 dev_set_name(&spi
->dev
, "spi-%s", acpi_dev_name(adev
));
530 dev_set_name(&spi
->dev
, "%s.%u", dev_name(&spi
->controller
->dev
),
534 static int spi_dev_check(struct device
*dev
, void *data
)
536 struct spi_device
*spi
= to_spi_device(dev
);
537 struct spi_device
*new_spi
= data
;
539 if (spi
->controller
== new_spi
->controller
&&
540 spi
->chip_select
== new_spi
->chip_select
)
546 * spi_add_device - Add spi_device allocated with spi_alloc_device
547 * @spi: spi_device to register
549 * Companion function to spi_alloc_device. Devices allocated with
550 * spi_alloc_device can be added onto the spi bus with this function.
552 * Return: 0 on success; negative errno on failure
554 int spi_add_device(struct spi_device
*spi
)
556 static DEFINE_MUTEX(spi_add_lock
);
557 struct spi_controller
*ctlr
= spi
->controller
;
558 struct device
*dev
= ctlr
->dev
.parent
;
561 /* Chipselects are numbered 0..max; validate. */
562 if (spi
->chip_select
>= ctlr
->num_chipselect
) {
563 dev_err(dev
, "cs%d >= max %d\n", spi
->chip_select
,
564 ctlr
->num_chipselect
);
568 /* Set the bus ID string */
569 spi_dev_set_name(spi
);
571 /* We need to make sure there's no other device with this
572 * chipselect **BEFORE** we call setup(), else we'll trash
573 * its configuration. Lock against concurrent add() calls.
575 mutex_lock(&spi_add_lock
);
577 status
= bus_for_each_dev(&spi_bus_type
, NULL
, spi
, spi_dev_check
);
579 dev_err(dev
, "chipselect %d already in use\n",
584 /* Descriptors take precedence */
586 spi
->cs_gpiod
= ctlr
->cs_gpiods
[spi
->chip_select
];
587 else if (ctlr
->cs_gpios
)
588 spi
->cs_gpio
= ctlr
->cs_gpios
[spi
->chip_select
];
590 /* Drivers may modify this initial i/o setup, but will
591 * normally rely on the device being setup. Devices
592 * using SPI_CS_HIGH can't coexist well otherwise...
594 status
= spi_setup(spi
);
596 dev_err(dev
, "can't setup %s, status %d\n",
597 dev_name(&spi
->dev
), status
);
601 /* Device may be bound to an active driver when this returns */
602 status
= device_add(&spi
->dev
);
604 dev_err(dev
, "can't add %s, status %d\n",
605 dev_name(&spi
->dev
), status
);
607 dev_dbg(dev
, "registered child %s\n", dev_name(&spi
->dev
));
610 mutex_unlock(&spi_add_lock
);
613 EXPORT_SYMBOL_GPL(spi_add_device
);
616 * spi_new_device - instantiate one new SPI device
617 * @ctlr: Controller to which device is connected
618 * @chip: Describes the SPI device
621 * On typical mainboards, this is purely internal; and it's not needed
622 * after board init creates the hard-wired devices. Some development
623 * platforms may not be able to use spi_register_board_info though, and
624 * this is exported so that for example a USB or parport based adapter
625 * driver could add devices (which it would learn about out-of-band).
627 * Return: the new device, or NULL.
629 struct spi_device
*spi_new_device(struct spi_controller
*ctlr
,
630 struct spi_board_info
*chip
)
632 struct spi_device
*proxy
;
635 /* NOTE: caller did any chip->bus_num checks necessary.
637 * Also, unless we change the return value convention to use
638 * error-or-pointer (not NULL-or-pointer), troubleshootability
639 * suggests syslogged diagnostics are best here (ugh).
642 proxy
= spi_alloc_device(ctlr
);
646 WARN_ON(strlen(chip
->modalias
) >= sizeof(proxy
->modalias
));
648 proxy
->chip_select
= chip
->chip_select
;
649 proxy
->max_speed_hz
= chip
->max_speed_hz
;
650 proxy
->mode
= chip
->mode
;
651 proxy
->irq
= chip
->irq
;
652 strlcpy(proxy
->modalias
, chip
->modalias
, sizeof(proxy
->modalias
));
653 proxy
->dev
.platform_data
= (void *) chip
->platform_data
;
654 proxy
->controller_data
= chip
->controller_data
;
655 proxy
->controller_state
= NULL
;
657 if (chip
->properties
) {
658 status
= device_add_properties(&proxy
->dev
, chip
->properties
);
661 "failed to add properties to '%s': %d\n",
662 chip
->modalias
, status
);
667 status
= spi_add_device(proxy
);
669 goto err_remove_props
;
674 if (chip
->properties
)
675 device_remove_properties(&proxy
->dev
);
680 EXPORT_SYMBOL_GPL(spi_new_device
);
683 * spi_unregister_device - unregister a single SPI device
684 * @spi: spi_device to unregister
686 * Start making the passed SPI device vanish. Normally this would be handled
687 * by spi_unregister_controller().
689 void spi_unregister_device(struct spi_device
*spi
)
694 if (spi
->dev
.of_node
) {
695 of_node_clear_flag(spi
->dev
.of_node
, OF_POPULATED
);
696 of_node_put(spi
->dev
.of_node
);
698 if (ACPI_COMPANION(&spi
->dev
))
699 acpi_device_clear_enumerated(ACPI_COMPANION(&spi
->dev
));
700 device_unregister(&spi
->dev
);
702 EXPORT_SYMBOL_GPL(spi_unregister_device
);
704 static void spi_match_controller_to_boardinfo(struct spi_controller
*ctlr
,
705 struct spi_board_info
*bi
)
707 struct spi_device
*dev
;
709 if (ctlr
->bus_num
!= bi
->bus_num
)
712 dev
= spi_new_device(ctlr
, bi
);
714 dev_err(ctlr
->dev
.parent
, "can't create new device for %s\n",
719 * spi_register_board_info - register SPI devices for a given board
720 * @info: array of chip descriptors
721 * @n: how many descriptors are provided
724 * Board-specific early init code calls this (probably during arch_initcall)
725 * with segments of the SPI device table. Any device nodes are created later,
726 * after the relevant parent SPI controller (bus_num) is defined. We keep
727 * this table of devices forever, so that reloading a controller driver will
728 * not make Linux forget about these hard-wired devices.
730 * Other code can also call this, e.g. a particular add-on board might provide
731 * SPI devices through its expansion connector, so code initializing that board
732 * would naturally declare its SPI devices.
734 * The board info passed can safely be __initdata ... but be careful of
735 * any embedded pointers (platform_data, etc), they're copied as-is.
736 * Device properties are deep-copied though.
738 * Return: zero on success, else a negative error code.
740 int spi_register_board_info(struct spi_board_info
const *info
, unsigned n
)
742 struct boardinfo
*bi
;
748 bi
= kcalloc(n
, sizeof(*bi
), GFP_KERNEL
);
752 for (i
= 0; i
< n
; i
++, bi
++, info
++) {
753 struct spi_controller
*ctlr
;
755 memcpy(&bi
->board_info
, info
, sizeof(*info
));
756 if (info
->properties
) {
757 bi
->board_info
.properties
=
758 property_entries_dup(info
->properties
);
759 if (IS_ERR(bi
->board_info
.properties
))
760 return PTR_ERR(bi
->board_info
.properties
);
763 mutex_lock(&board_lock
);
764 list_add_tail(&bi
->list
, &board_list
);
765 list_for_each_entry(ctlr
, &spi_controller_list
, list
)
766 spi_match_controller_to_boardinfo(ctlr
,
768 mutex_unlock(&board_lock
);
774 /*-------------------------------------------------------------------------*/
776 static void spi_set_cs(struct spi_device
*spi
, bool enable
)
778 if (spi
->mode
& SPI_CS_HIGH
)
781 if (spi
->cs_gpiod
|| gpio_is_valid(spi
->cs_gpio
)) {
783 * Honour the SPI_NO_CS flag and invert the enable line, as
784 * active low is default for SPI. Execution paths that handle
785 * polarity inversion in gpiolib (such as device tree) will
786 * enforce active high using the SPI_CS_HIGH resulting in a
787 * double inversion through the code above.
789 if (!(spi
->mode
& SPI_NO_CS
)) {
791 gpiod_set_value_cansleep(spi
->cs_gpiod
,
794 gpio_set_value_cansleep(spi
->cs_gpio
, !enable
);
796 /* Some SPI masters need both GPIO CS & slave_select */
797 if ((spi
->controller
->flags
& SPI_MASTER_GPIO_SS
) &&
798 spi
->controller
->set_cs
)
799 spi
->controller
->set_cs(spi
, !enable
);
800 } else if (spi
->controller
->set_cs
) {
801 spi
->controller
->set_cs(spi
, !enable
);
805 #ifdef CONFIG_HAS_DMA
806 int spi_map_buf(struct spi_controller
*ctlr
, struct device
*dev
,
807 struct sg_table
*sgt
, void *buf
, size_t len
,
808 enum dma_data_direction dir
)
810 const bool vmalloced_buf
= is_vmalloc_addr(buf
);
811 unsigned int max_seg_size
= dma_get_max_seg_size(dev
);
812 #ifdef CONFIG_HIGHMEM
813 const bool kmap_buf
= ((unsigned long)buf
>= PKMAP_BASE
&&
814 (unsigned long)buf
< (PKMAP_BASE
+
815 (LAST_PKMAP
* PAGE_SIZE
)));
817 const bool kmap_buf
= false;
821 struct page
*vm_page
;
822 struct scatterlist
*sg
;
827 if (vmalloced_buf
|| kmap_buf
) {
828 desc_len
= min_t(int, max_seg_size
, PAGE_SIZE
);
829 sgs
= DIV_ROUND_UP(len
+ offset_in_page(buf
), desc_len
);
830 } else if (virt_addr_valid(buf
)) {
831 desc_len
= min_t(int, max_seg_size
, ctlr
->max_dma_len
);
832 sgs
= DIV_ROUND_UP(len
, desc_len
);
837 ret
= sg_alloc_table(sgt
, sgs
, GFP_KERNEL
);
842 for (i
= 0; i
< sgs
; i
++) {
844 if (vmalloced_buf
|| kmap_buf
) {
846 * Next scatterlist entry size is the minimum between
847 * the desc_len and the remaining buffer length that
850 min
= min_t(size_t, desc_len
,
852 PAGE_SIZE
- offset_in_page(buf
)));
854 vm_page
= vmalloc_to_page(buf
);
856 vm_page
= kmap_to_page(buf
);
861 sg_set_page(sg
, vm_page
,
862 min
, offset_in_page(buf
));
864 min
= min_t(size_t, len
, desc_len
);
866 sg_set_buf(sg
, sg_buf
, min
);
874 ret
= dma_map_sg(dev
, sgt
->sgl
, sgt
->nents
, dir
);
887 void spi_unmap_buf(struct spi_controller
*ctlr
, struct device
*dev
,
888 struct sg_table
*sgt
, enum dma_data_direction dir
)
890 if (sgt
->orig_nents
) {
891 dma_unmap_sg(dev
, sgt
->sgl
, sgt
->orig_nents
, dir
);
896 static int __spi_map_msg(struct spi_controller
*ctlr
, struct spi_message
*msg
)
898 struct device
*tx_dev
, *rx_dev
;
899 struct spi_transfer
*xfer
;
906 tx_dev
= ctlr
->dma_tx
->device
->dev
;
908 tx_dev
= ctlr
->dev
.parent
;
911 rx_dev
= ctlr
->dma_rx
->device
->dev
;
913 rx_dev
= ctlr
->dev
.parent
;
915 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
916 if (!ctlr
->can_dma(ctlr
, msg
->spi
, xfer
))
919 if (xfer
->tx_buf
!= NULL
) {
920 ret
= spi_map_buf(ctlr
, tx_dev
, &xfer
->tx_sg
,
921 (void *)xfer
->tx_buf
, xfer
->len
,
927 if (xfer
->rx_buf
!= NULL
) {
928 ret
= spi_map_buf(ctlr
, rx_dev
, &xfer
->rx_sg
,
929 xfer
->rx_buf
, xfer
->len
,
932 spi_unmap_buf(ctlr
, tx_dev
, &xfer
->tx_sg
,
939 ctlr
->cur_msg_mapped
= true;
944 static int __spi_unmap_msg(struct spi_controller
*ctlr
, struct spi_message
*msg
)
946 struct spi_transfer
*xfer
;
947 struct device
*tx_dev
, *rx_dev
;
949 if (!ctlr
->cur_msg_mapped
|| !ctlr
->can_dma
)
953 tx_dev
= ctlr
->dma_tx
->device
->dev
;
955 tx_dev
= ctlr
->dev
.parent
;
958 rx_dev
= ctlr
->dma_rx
->device
->dev
;
960 rx_dev
= ctlr
->dev
.parent
;
962 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
963 if (!ctlr
->can_dma(ctlr
, msg
->spi
, xfer
))
966 spi_unmap_buf(ctlr
, rx_dev
, &xfer
->rx_sg
, DMA_FROM_DEVICE
);
967 spi_unmap_buf(ctlr
, tx_dev
, &xfer
->tx_sg
, DMA_TO_DEVICE
);
972 #else /* !CONFIG_HAS_DMA */
973 static inline int __spi_map_msg(struct spi_controller
*ctlr
,
974 struct spi_message
*msg
)
979 static inline int __spi_unmap_msg(struct spi_controller
*ctlr
,
980 struct spi_message
*msg
)
984 #endif /* !CONFIG_HAS_DMA */
986 static inline int spi_unmap_msg(struct spi_controller
*ctlr
,
987 struct spi_message
*msg
)
989 struct spi_transfer
*xfer
;
991 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
993 * Restore the original value of tx_buf or rx_buf if they are
996 if (xfer
->tx_buf
== ctlr
->dummy_tx
)
998 if (xfer
->rx_buf
== ctlr
->dummy_rx
)
1002 return __spi_unmap_msg(ctlr
, msg
);
1005 static int spi_map_msg(struct spi_controller
*ctlr
, struct spi_message
*msg
)
1007 struct spi_transfer
*xfer
;
1009 unsigned int max_tx
, max_rx
;
1011 if (ctlr
->flags
& (SPI_CONTROLLER_MUST_RX
| SPI_CONTROLLER_MUST_TX
)) {
1015 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
1016 if ((ctlr
->flags
& SPI_CONTROLLER_MUST_TX
) &&
1018 max_tx
= max(xfer
->len
, max_tx
);
1019 if ((ctlr
->flags
& SPI_CONTROLLER_MUST_RX
) &&
1021 max_rx
= max(xfer
->len
, max_rx
);
1025 tmp
= krealloc(ctlr
->dummy_tx
, max_tx
,
1026 GFP_KERNEL
| GFP_DMA
);
1029 ctlr
->dummy_tx
= tmp
;
1030 memset(tmp
, 0, max_tx
);
1034 tmp
= krealloc(ctlr
->dummy_rx
, max_rx
,
1035 GFP_KERNEL
| GFP_DMA
);
1038 ctlr
->dummy_rx
= tmp
;
1041 if (max_tx
|| max_rx
) {
1042 list_for_each_entry(xfer
, &msg
->transfers
,
1047 xfer
->tx_buf
= ctlr
->dummy_tx
;
1049 xfer
->rx_buf
= ctlr
->dummy_rx
;
1054 return __spi_map_msg(ctlr
, msg
);
1057 static int spi_transfer_wait(struct spi_controller
*ctlr
,
1058 struct spi_message
*msg
,
1059 struct spi_transfer
*xfer
)
1061 struct spi_statistics
*statm
= &ctlr
->statistics
;
1062 struct spi_statistics
*stats
= &msg
->spi
->statistics
;
1063 unsigned long long ms
= 1;
1065 if (spi_controller_is_slave(ctlr
)) {
1066 if (wait_for_completion_interruptible(&ctlr
->xfer_completion
)) {
1067 dev_dbg(&msg
->spi
->dev
, "SPI transfer interrupted\n");
1071 ms
= 8LL * 1000LL * xfer
->len
;
1072 do_div(ms
, xfer
->speed_hz
);
1073 ms
+= ms
+ 200; /* some tolerance */
1078 ms
= wait_for_completion_timeout(&ctlr
->xfer_completion
,
1079 msecs_to_jiffies(ms
));
1082 SPI_STATISTICS_INCREMENT_FIELD(statm
, timedout
);
1083 SPI_STATISTICS_INCREMENT_FIELD(stats
, timedout
);
1084 dev_err(&msg
->spi
->dev
,
1085 "SPI transfer timed out\n");
1094 * spi_transfer_one_message - Default implementation of transfer_one_message()
1096 * This is a standard implementation of transfer_one_message() for
1097 * drivers which implement a transfer_one() operation. It provides
1098 * standard handling of delays and chip select management.
1100 static int spi_transfer_one_message(struct spi_controller
*ctlr
,
1101 struct spi_message
*msg
)
1103 struct spi_transfer
*xfer
;
1104 bool keep_cs
= false;
1106 struct spi_statistics
*statm
= &ctlr
->statistics
;
1107 struct spi_statistics
*stats
= &msg
->spi
->statistics
;
1109 spi_set_cs(msg
->spi
, true);
1111 SPI_STATISTICS_INCREMENT_FIELD(statm
, messages
);
1112 SPI_STATISTICS_INCREMENT_FIELD(stats
, messages
);
1114 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
1115 trace_spi_transfer_start(msg
, xfer
);
1117 spi_statistics_add_transfer_stats(statm
, xfer
, ctlr
);
1118 spi_statistics_add_transfer_stats(stats
, xfer
, ctlr
);
1120 if (xfer
->tx_buf
|| xfer
->rx_buf
) {
1121 reinit_completion(&ctlr
->xfer_completion
);
1123 ret
= ctlr
->transfer_one(ctlr
, msg
->spi
, xfer
);
1125 SPI_STATISTICS_INCREMENT_FIELD(statm
,
1127 SPI_STATISTICS_INCREMENT_FIELD(stats
,
1129 dev_err(&msg
->spi
->dev
,
1130 "SPI transfer failed: %d\n", ret
);
1135 ret
= spi_transfer_wait(ctlr
, msg
, xfer
);
1141 dev_err(&msg
->spi
->dev
,
1142 "Bufferless transfer has length %u\n",
1146 trace_spi_transfer_stop(msg
, xfer
);
1148 if (msg
->status
!= -EINPROGRESS
)
1151 if (xfer
->delay_usecs
) {
1152 u16 us
= xfer
->delay_usecs
;
1157 usleep_range(us
, us
+ DIV_ROUND_UP(us
, 10));
1160 if (xfer
->cs_change
) {
1161 if (list_is_last(&xfer
->transfer_list
,
1165 spi_set_cs(msg
->spi
, false);
1167 spi_set_cs(msg
->spi
, true);
1171 msg
->actual_length
+= xfer
->len
;
1175 if (ret
!= 0 || !keep_cs
)
1176 spi_set_cs(msg
->spi
, false);
1178 if (msg
->status
== -EINPROGRESS
)
1181 if (msg
->status
&& ctlr
->handle_err
)
1182 ctlr
->handle_err(ctlr
, msg
);
1184 spi_res_release(ctlr
, msg
);
1186 spi_finalize_current_message(ctlr
);
1192 * spi_finalize_current_transfer - report completion of a transfer
1193 * @ctlr: the controller reporting completion
1195 * Called by SPI drivers using the core transfer_one_message()
1196 * implementation to notify it that the current interrupt driven
1197 * transfer has finished and the next one may be scheduled.
1199 void spi_finalize_current_transfer(struct spi_controller
*ctlr
)
1201 complete(&ctlr
->xfer_completion
);
1203 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer
);
1206 * __spi_pump_messages - function which processes spi message queue
1207 * @ctlr: controller to process queue for
1208 * @in_kthread: true if we are in the context of the message pump thread
1210 * This function checks if there is any spi message in the queue that
1211 * needs processing and if so call out to the driver to initialize hardware
1212 * and transfer each message.
1214 * Note that it is called both from the kthread itself and also from
1215 * inside spi_sync(); the queue extraction handling at the top of the
1216 * function should deal with this safely.
1218 static void __spi_pump_messages(struct spi_controller
*ctlr
, bool in_kthread
)
1220 unsigned long flags
;
1221 bool was_busy
= false;
1225 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1227 /* Make sure we are not already running a message */
1228 if (ctlr
->cur_msg
) {
1229 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1233 /* If another context is idling the device then defer */
1235 kthread_queue_work(&ctlr
->kworker
, &ctlr
->pump_messages
);
1236 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1240 /* Check if the queue is idle */
1241 if (list_empty(&ctlr
->queue
) || !ctlr
->running
) {
1243 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1247 /* Only do teardown in the thread */
1249 kthread_queue_work(&ctlr
->kworker
,
1250 &ctlr
->pump_messages
);
1251 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1256 ctlr
->idling
= true;
1257 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1259 kfree(ctlr
->dummy_rx
);
1260 ctlr
->dummy_rx
= NULL
;
1261 kfree(ctlr
->dummy_tx
);
1262 ctlr
->dummy_tx
= NULL
;
1263 if (ctlr
->unprepare_transfer_hardware
&&
1264 ctlr
->unprepare_transfer_hardware(ctlr
))
1266 "failed to unprepare transfer hardware\n");
1267 if (ctlr
->auto_runtime_pm
) {
1268 pm_runtime_mark_last_busy(ctlr
->dev
.parent
);
1269 pm_runtime_put_autosuspend(ctlr
->dev
.parent
);
1271 trace_spi_controller_idle(ctlr
);
1273 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1274 ctlr
->idling
= false;
1275 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1279 /* Extract head of queue */
1281 list_first_entry(&ctlr
->queue
, struct spi_message
, queue
);
1283 list_del_init(&ctlr
->cur_msg
->queue
);
1288 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1290 mutex_lock(&ctlr
->io_mutex
);
1292 if (!was_busy
&& ctlr
->auto_runtime_pm
) {
1293 ret
= pm_runtime_get_sync(ctlr
->dev
.parent
);
1295 pm_runtime_put_noidle(ctlr
->dev
.parent
);
1296 dev_err(&ctlr
->dev
, "Failed to power device: %d\n",
1298 mutex_unlock(&ctlr
->io_mutex
);
1304 trace_spi_controller_busy(ctlr
);
1306 if (!was_busy
&& ctlr
->prepare_transfer_hardware
) {
1307 ret
= ctlr
->prepare_transfer_hardware(ctlr
);
1310 "failed to prepare transfer hardware: %d\n",
1313 if (ctlr
->auto_runtime_pm
)
1314 pm_runtime_put(ctlr
->dev
.parent
);
1316 ctlr
->cur_msg
->status
= ret
;
1317 spi_finalize_current_message(ctlr
);
1319 mutex_unlock(&ctlr
->io_mutex
);
1324 trace_spi_message_start(ctlr
->cur_msg
);
1326 if (ctlr
->prepare_message
) {
1327 ret
= ctlr
->prepare_message(ctlr
, ctlr
->cur_msg
);
1329 dev_err(&ctlr
->dev
, "failed to prepare message: %d\n",
1331 ctlr
->cur_msg
->status
= ret
;
1332 spi_finalize_current_message(ctlr
);
1335 ctlr
->cur_msg_prepared
= true;
1338 ret
= spi_map_msg(ctlr
, ctlr
->cur_msg
);
1340 ctlr
->cur_msg
->status
= ret
;
1341 spi_finalize_current_message(ctlr
);
1345 ret
= ctlr
->transfer_one_message(ctlr
, ctlr
->cur_msg
);
1348 "failed to transfer one message from queue\n");
1353 mutex_unlock(&ctlr
->io_mutex
);
1355 /* Prod the scheduler in case transfer_one() was busy waiting */
1361 * spi_pump_messages - kthread work function which processes spi message queue
1362 * @work: pointer to kthread work struct contained in the controller struct
1364 static void spi_pump_messages(struct kthread_work
*work
)
1366 struct spi_controller
*ctlr
=
1367 container_of(work
, struct spi_controller
, pump_messages
);
1369 __spi_pump_messages(ctlr
, true);
1372 static int spi_init_queue(struct spi_controller
*ctlr
)
1374 struct sched_param param
= { .sched_priority
= MAX_RT_PRIO
- 1 };
1376 ctlr
->running
= false;
1379 kthread_init_worker(&ctlr
->kworker
);
1380 ctlr
->kworker_task
= kthread_run(kthread_worker_fn
, &ctlr
->kworker
,
1381 "%s", dev_name(&ctlr
->dev
));
1382 if (IS_ERR(ctlr
->kworker_task
)) {
1383 dev_err(&ctlr
->dev
, "failed to create message pump task\n");
1384 return PTR_ERR(ctlr
->kworker_task
);
1386 kthread_init_work(&ctlr
->pump_messages
, spi_pump_messages
);
1389 * Controller config will indicate if this controller should run the
1390 * message pump with high (realtime) priority to reduce the transfer
1391 * latency on the bus by minimising the delay between a transfer
1392 * request and the scheduling of the message pump thread. Without this
1393 * setting the message pump thread will remain at default priority.
1396 dev_info(&ctlr
->dev
,
1397 "will run message pump with realtime priority\n");
1398 sched_setscheduler(ctlr
->kworker_task
, SCHED_FIFO
, ¶m
);
1405 * spi_get_next_queued_message() - called by driver to check for queued
1407 * @ctlr: the controller to check for queued messages
1409 * If there are more messages in the queue, the next message is returned from
1412 * Return: the next message in the queue, else NULL if the queue is empty.
1414 struct spi_message
*spi_get_next_queued_message(struct spi_controller
*ctlr
)
1416 struct spi_message
*next
;
1417 unsigned long flags
;
1419 /* get a pointer to the next message, if any */
1420 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1421 next
= list_first_entry_or_null(&ctlr
->queue
, struct spi_message
,
1423 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1427 EXPORT_SYMBOL_GPL(spi_get_next_queued_message
);
1430 * spi_finalize_current_message() - the current message is complete
1431 * @ctlr: the controller to return the message to
1433 * Called by the driver to notify the core that the message in the front of the
1434 * queue is complete and can be removed from the queue.
1436 void spi_finalize_current_message(struct spi_controller
*ctlr
)
1438 struct spi_message
*mesg
;
1439 unsigned long flags
;
1442 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1443 mesg
= ctlr
->cur_msg
;
1444 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1446 spi_unmap_msg(ctlr
, mesg
);
1448 if (ctlr
->cur_msg_prepared
&& ctlr
->unprepare_message
) {
1449 ret
= ctlr
->unprepare_message(ctlr
, mesg
);
1451 dev_err(&ctlr
->dev
, "failed to unprepare message: %d\n",
1456 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1457 ctlr
->cur_msg
= NULL
;
1458 ctlr
->cur_msg_prepared
= false;
1459 kthread_queue_work(&ctlr
->kworker
, &ctlr
->pump_messages
);
1460 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1462 trace_spi_message_done(mesg
);
1466 mesg
->complete(mesg
->context
);
1468 EXPORT_SYMBOL_GPL(spi_finalize_current_message
);
1470 static int spi_start_queue(struct spi_controller
*ctlr
)
1472 unsigned long flags
;
1474 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1476 if (ctlr
->running
|| ctlr
->busy
) {
1477 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1481 ctlr
->running
= true;
1482 ctlr
->cur_msg
= NULL
;
1483 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1485 kthread_queue_work(&ctlr
->kworker
, &ctlr
->pump_messages
);
1490 static int spi_stop_queue(struct spi_controller
*ctlr
)
1492 unsigned long flags
;
1493 unsigned limit
= 500;
1496 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1499 * This is a bit lame, but is optimized for the common execution path.
1500 * A wait_queue on the ctlr->busy could be used, but then the common
1501 * execution path (pump_messages) would be required to call wake_up or
1502 * friends on every SPI message. Do this instead.
1504 while ((!list_empty(&ctlr
->queue
) || ctlr
->busy
) && limit
--) {
1505 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1506 usleep_range(10000, 11000);
1507 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1510 if (!list_empty(&ctlr
->queue
) || ctlr
->busy
)
1513 ctlr
->running
= false;
1515 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1518 dev_warn(&ctlr
->dev
, "could not stop message queue\n");
1524 static int spi_destroy_queue(struct spi_controller
*ctlr
)
1528 ret
= spi_stop_queue(ctlr
);
1531 * kthread_flush_worker will block until all work is done.
1532 * If the reason that stop_queue timed out is that the work will never
1533 * finish, then it does no good to call flush/stop thread, so
1537 dev_err(&ctlr
->dev
, "problem destroying queue\n");
1541 kthread_flush_worker(&ctlr
->kworker
);
1542 kthread_stop(ctlr
->kworker_task
);
1547 static int __spi_queued_transfer(struct spi_device
*spi
,
1548 struct spi_message
*msg
,
1551 struct spi_controller
*ctlr
= spi
->controller
;
1552 unsigned long flags
;
1554 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1556 if (!ctlr
->running
) {
1557 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1560 msg
->actual_length
= 0;
1561 msg
->status
= -EINPROGRESS
;
1563 list_add_tail(&msg
->queue
, &ctlr
->queue
);
1564 if (!ctlr
->busy
&& need_pump
)
1565 kthread_queue_work(&ctlr
->kworker
, &ctlr
->pump_messages
);
1567 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1572 * spi_queued_transfer - transfer function for queued transfers
1573 * @spi: spi device which is requesting transfer
1574 * @msg: spi message which is to handled is queued to driver queue
1576 * Return: zero on success, else a negative error code.
1578 static int spi_queued_transfer(struct spi_device
*spi
, struct spi_message
*msg
)
1580 return __spi_queued_transfer(spi
, msg
, true);
1583 static int spi_controller_initialize_queue(struct spi_controller
*ctlr
)
1587 ctlr
->transfer
= spi_queued_transfer
;
1588 if (!ctlr
->transfer_one_message
)
1589 ctlr
->transfer_one_message
= spi_transfer_one_message
;
1591 /* Initialize and start queue */
1592 ret
= spi_init_queue(ctlr
);
1594 dev_err(&ctlr
->dev
, "problem initializing queue\n");
1595 goto err_init_queue
;
1597 ctlr
->queued
= true;
1598 ret
= spi_start_queue(ctlr
);
1600 dev_err(&ctlr
->dev
, "problem starting queue\n");
1601 goto err_start_queue
;
1607 spi_destroy_queue(ctlr
);
1613 * spi_flush_queue - Send all pending messages in the queue from the callers'
1615 * @ctlr: controller to process queue for
1617 * This should be used when one wants to ensure all pending messages have been
1618 * sent before doing something. Is used by the spi-mem code to make sure SPI
1619 * memory operations do not preempt regular SPI transfers that have been queued
1620 * before the spi-mem operation.
1622 void spi_flush_queue(struct spi_controller
*ctlr
)
1624 if (ctlr
->transfer
== spi_queued_transfer
)
1625 __spi_pump_messages(ctlr
, false);
1628 /*-------------------------------------------------------------------------*/
1630 #if defined(CONFIG_OF)
1631 static int of_spi_parse_dt(struct spi_controller
*ctlr
, struct spi_device
*spi
,
1632 struct device_node
*nc
)
1637 /* Mode (clock phase/polarity/etc.) */
1638 if (of_property_read_bool(nc
, "spi-cpha"))
1639 spi
->mode
|= SPI_CPHA
;
1640 if (of_property_read_bool(nc
, "spi-cpol"))
1641 spi
->mode
|= SPI_CPOL
;
1642 if (of_property_read_bool(nc
, "spi-3wire"))
1643 spi
->mode
|= SPI_3WIRE
;
1644 if (of_property_read_bool(nc
, "spi-lsb-first"))
1645 spi
->mode
|= SPI_LSB_FIRST
;
1648 * For descriptors associated with the device, polarity inversion is
1649 * handled in the gpiolib, so all chip selects are "active high" in
1650 * the logical sense, the gpiolib will invert the line if need be.
1652 if (ctlr
->use_gpio_descriptors
)
1653 spi
->mode
|= SPI_CS_HIGH
;
1654 else if (of_property_read_bool(nc
, "spi-cs-high"))
1655 spi
->mode
|= SPI_CS_HIGH
;
1657 /* Device DUAL/QUAD mode */
1658 if (!of_property_read_u32(nc
, "spi-tx-bus-width", &value
)) {
1663 spi
->mode
|= SPI_TX_DUAL
;
1666 spi
->mode
|= SPI_TX_QUAD
;
1669 spi
->mode
|= SPI_TX_OCTAL
;
1672 dev_warn(&ctlr
->dev
,
1673 "spi-tx-bus-width %d not supported\n",
1679 if (!of_property_read_u32(nc
, "spi-rx-bus-width", &value
)) {
1684 spi
->mode
|= SPI_RX_DUAL
;
1687 spi
->mode
|= SPI_RX_QUAD
;
1690 spi
->mode
|= SPI_RX_OCTAL
;
1693 dev_warn(&ctlr
->dev
,
1694 "spi-rx-bus-width %d not supported\n",
1700 if (spi_controller_is_slave(ctlr
)) {
1701 if (!of_node_name_eq(nc
, "slave")) {
1702 dev_err(&ctlr
->dev
, "%pOF is not called 'slave'\n",
1709 /* Device address */
1710 rc
= of_property_read_u32(nc
, "reg", &value
);
1712 dev_err(&ctlr
->dev
, "%pOF has no valid 'reg' property (%d)\n",
1716 spi
->chip_select
= value
;
1719 rc
= of_property_read_u32(nc
, "spi-max-frequency", &value
);
1722 "%pOF has no valid 'spi-max-frequency' property (%d)\n", nc
, rc
);
1725 spi
->max_speed_hz
= value
;
1730 static struct spi_device
*
1731 of_register_spi_device(struct spi_controller
*ctlr
, struct device_node
*nc
)
1733 struct spi_device
*spi
;
1736 /* Alloc an spi_device */
1737 spi
= spi_alloc_device(ctlr
);
1739 dev_err(&ctlr
->dev
, "spi_device alloc error for %pOF\n", nc
);
1744 /* Select device driver */
1745 rc
= of_modalias_node(nc
, spi
->modalias
,
1746 sizeof(spi
->modalias
));
1748 dev_err(&ctlr
->dev
, "cannot find modalias for %pOF\n", nc
);
1752 rc
= of_spi_parse_dt(ctlr
, spi
, nc
);
1756 /* Store a pointer to the node in the device structure */
1758 spi
->dev
.of_node
= nc
;
1760 /* Register the new device */
1761 rc
= spi_add_device(spi
);
1763 dev_err(&ctlr
->dev
, "spi_device register error %pOF\n", nc
);
1764 goto err_of_node_put
;
1777 * of_register_spi_devices() - Register child devices onto the SPI bus
1778 * @ctlr: Pointer to spi_controller device
1780 * Registers an spi_device for each child node of controller node which
1781 * represents a valid SPI slave.
1783 static void of_register_spi_devices(struct spi_controller
*ctlr
)
1785 struct spi_device
*spi
;
1786 struct device_node
*nc
;
1788 if (!ctlr
->dev
.of_node
)
1791 for_each_available_child_of_node(ctlr
->dev
.of_node
, nc
) {
1792 if (of_node_test_and_set_flag(nc
, OF_POPULATED
))
1794 spi
= of_register_spi_device(ctlr
, nc
);
1796 dev_warn(&ctlr
->dev
,
1797 "Failed to create SPI device for %pOF\n", nc
);
1798 of_node_clear_flag(nc
, OF_POPULATED
);
1803 static void of_register_spi_devices(struct spi_controller
*ctlr
) { }
1807 static void acpi_spi_parse_apple_properties(struct spi_device
*spi
)
1809 struct acpi_device
*dev
= ACPI_COMPANION(&spi
->dev
);
1810 const union acpi_object
*obj
;
1812 if (!x86_apple_machine
)
1815 if (!acpi_dev_get_property(dev
, "spiSclkPeriod", ACPI_TYPE_BUFFER
, &obj
)
1816 && obj
->buffer
.length
>= 4)
1817 spi
->max_speed_hz
= NSEC_PER_SEC
/ *(u32
*)obj
->buffer
.pointer
;
1819 if (!acpi_dev_get_property(dev
, "spiWordSize", ACPI_TYPE_BUFFER
, &obj
)
1820 && obj
->buffer
.length
== 8)
1821 spi
->bits_per_word
= *(u64
*)obj
->buffer
.pointer
;
1823 if (!acpi_dev_get_property(dev
, "spiBitOrder", ACPI_TYPE_BUFFER
, &obj
)
1824 && obj
->buffer
.length
== 8 && !*(u64
*)obj
->buffer
.pointer
)
1825 spi
->mode
|= SPI_LSB_FIRST
;
1827 if (!acpi_dev_get_property(dev
, "spiSPO", ACPI_TYPE_BUFFER
, &obj
)
1828 && obj
->buffer
.length
== 8 && *(u64
*)obj
->buffer
.pointer
)
1829 spi
->mode
|= SPI_CPOL
;
1831 if (!acpi_dev_get_property(dev
, "spiSPH", ACPI_TYPE_BUFFER
, &obj
)
1832 && obj
->buffer
.length
== 8 && *(u64
*)obj
->buffer
.pointer
)
1833 spi
->mode
|= SPI_CPHA
;
1836 static int acpi_spi_add_resource(struct acpi_resource
*ares
, void *data
)
1838 struct spi_device
*spi
= data
;
1839 struct spi_controller
*ctlr
= spi
->controller
;
1841 if (ares
->type
== ACPI_RESOURCE_TYPE_SERIAL_BUS
) {
1842 struct acpi_resource_spi_serialbus
*sb
;
1844 sb
= &ares
->data
.spi_serial_bus
;
1845 if (sb
->type
== ACPI_RESOURCE_SERIAL_TYPE_SPI
) {
1847 * ACPI DeviceSelection numbering is handled by the
1848 * host controller driver in Windows and can vary
1849 * from driver to driver. In Linux we always expect
1850 * 0 .. max - 1 so we need to ask the driver to
1851 * translate between the two schemes.
1853 if (ctlr
->fw_translate_cs
) {
1854 int cs
= ctlr
->fw_translate_cs(ctlr
,
1855 sb
->device_selection
);
1858 spi
->chip_select
= cs
;
1860 spi
->chip_select
= sb
->device_selection
;
1863 spi
->max_speed_hz
= sb
->connection_speed
;
1865 if (sb
->clock_phase
== ACPI_SPI_SECOND_PHASE
)
1866 spi
->mode
|= SPI_CPHA
;
1867 if (sb
->clock_polarity
== ACPI_SPI_START_HIGH
)
1868 spi
->mode
|= SPI_CPOL
;
1869 if (sb
->device_polarity
== ACPI_SPI_ACTIVE_HIGH
)
1870 spi
->mode
|= SPI_CS_HIGH
;
1872 } else if (spi
->irq
< 0) {
1875 if (acpi_dev_resource_interrupt(ares
, 0, &r
))
1879 /* Always tell the ACPI core to skip this resource */
1883 static acpi_status
acpi_register_spi_device(struct spi_controller
*ctlr
,
1884 struct acpi_device
*adev
)
1886 struct list_head resource_list
;
1887 struct spi_device
*spi
;
1890 if (acpi_bus_get_status(adev
) || !adev
->status
.present
||
1891 acpi_device_enumerated(adev
))
1894 spi
= spi_alloc_device(ctlr
);
1896 dev_err(&ctlr
->dev
, "failed to allocate SPI device for %s\n",
1897 dev_name(&adev
->dev
));
1898 return AE_NO_MEMORY
;
1901 ACPI_COMPANION_SET(&spi
->dev
, adev
);
1904 INIT_LIST_HEAD(&resource_list
);
1905 ret
= acpi_dev_get_resources(adev
, &resource_list
,
1906 acpi_spi_add_resource
, spi
);
1907 acpi_dev_free_resource_list(&resource_list
);
1909 acpi_spi_parse_apple_properties(spi
);
1911 if (ret
< 0 || !spi
->max_speed_hz
) {
1916 acpi_set_modalias(adev
, acpi_device_hid(adev
), spi
->modalias
,
1917 sizeof(spi
->modalias
));
1920 spi
->irq
= acpi_dev_gpio_irq_get(adev
, 0);
1922 acpi_device_set_enumerated(adev
);
1924 adev
->power
.flags
.ignore_parent
= true;
1925 if (spi_add_device(spi
)) {
1926 adev
->power
.flags
.ignore_parent
= false;
1927 dev_err(&ctlr
->dev
, "failed to add SPI device %s from ACPI\n",
1928 dev_name(&adev
->dev
));
1935 static acpi_status
acpi_spi_add_device(acpi_handle handle
, u32 level
,
1936 void *data
, void **return_value
)
1938 struct spi_controller
*ctlr
= data
;
1939 struct acpi_device
*adev
;
1941 if (acpi_bus_get_device(handle
, &adev
))
1944 return acpi_register_spi_device(ctlr
, adev
);
1947 static void acpi_register_spi_devices(struct spi_controller
*ctlr
)
1952 handle
= ACPI_HANDLE(ctlr
->dev
.parent
);
1956 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, handle
, 1,
1957 acpi_spi_add_device
, NULL
, ctlr
, NULL
);
1958 if (ACPI_FAILURE(status
))
1959 dev_warn(&ctlr
->dev
, "failed to enumerate SPI slaves\n");
1962 static inline void acpi_register_spi_devices(struct spi_controller
*ctlr
) {}
1963 #endif /* CONFIG_ACPI */
1965 static void spi_controller_release(struct device
*dev
)
1967 struct spi_controller
*ctlr
;
1969 ctlr
= container_of(dev
, struct spi_controller
, dev
);
1973 static struct class spi_master_class
= {
1974 .name
= "spi_master",
1975 .owner
= THIS_MODULE
,
1976 .dev_release
= spi_controller_release
,
1977 .dev_groups
= spi_master_groups
,
1980 #ifdef CONFIG_SPI_SLAVE
1982 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
1984 * @spi: device used for the current transfer
1986 int spi_slave_abort(struct spi_device
*spi
)
1988 struct spi_controller
*ctlr
= spi
->controller
;
1990 if (spi_controller_is_slave(ctlr
) && ctlr
->slave_abort
)
1991 return ctlr
->slave_abort(ctlr
);
1995 EXPORT_SYMBOL_GPL(spi_slave_abort
);
1997 static int match_true(struct device
*dev
, void *data
)
2002 static ssize_t
spi_slave_show(struct device
*dev
,
2003 struct device_attribute
*attr
, char *buf
)
2005 struct spi_controller
*ctlr
= container_of(dev
, struct spi_controller
,
2007 struct device
*child
;
2009 child
= device_find_child(&ctlr
->dev
, NULL
, match_true
);
2010 return sprintf(buf
, "%s\n",
2011 child
? to_spi_device(child
)->modalias
: NULL
);
2014 static ssize_t
spi_slave_store(struct device
*dev
,
2015 struct device_attribute
*attr
, const char *buf
,
2018 struct spi_controller
*ctlr
= container_of(dev
, struct spi_controller
,
2020 struct spi_device
*spi
;
2021 struct device
*child
;
2025 rc
= sscanf(buf
, "%31s", name
);
2026 if (rc
!= 1 || !name
[0])
2029 child
= device_find_child(&ctlr
->dev
, NULL
, match_true
);
2031 /* Remove registered slave */
2032 device_unregister(child
);
2036 if (strcmp(name
, "(null)")) {
2037 /* Register new slave */
2038 spi
= spi_alloc_device(ctlr
);
2042 strlcpy(spi
->modalias
, name
, sizeof(spi
->modalias
));
2044 rc
= spi_add_device(spi
);
2054 static DEVICE_ATTR(slave
, 0644, spi_slave_show
, spi_slave_store
);
2056 static struct attribute
*spi_slave_attrs
[] = {
2057 &dev_attr_slave
.attr
,
2061 static const struct attribute_group spi_slave_group
= {
2062 .attrs
= spi_slave_attrs
,
2065 static const struct attribute_group
*spi_slave_groups
[] = {
2066 &spi_controller_statistics_group
,
2071 static struct class spi_slave_class
= {
2072 .name
= "spi_slave",
2073 .owner
= THIS_MODULE
,
2074 .dev_release
= spi_controller_release
,
2075 .dev_groups
= spi_slave_groups
,
2078 extern struct class spi_slave_class
; /* dummy */
2082 * __spi_alloc_controller - allocate an SPI master or slave controller
2083 * @dev: the controller, possibly using the platform_bus
2084 * @size: how much zeroed driver-private data to allocate; the pointer to this
2085 * memory is in the driver_data field of the returned device,
2086 * accessible with spi_controller_get_devdata().
2087 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2088 * slave (true) controller
2089 * Context: can sleep
2091 * This call is used only by SPI controller drivers, which are the
2092 * only ones directly touching chip registers. It's how they allocate
2093 * an spi_controller structure, prior to calling spi_register_controller().
2095 * This must be called from context that can sleep.
2097 * The caller is responsible for assigning the bus number and initializing the
2098 * controller's methods before calling spi_register_controller(); and (after
2099 * errors adding the device) calling spi_controller_put() to prevent a memory
2102 * Return: the SPI controller structure on success, else NULL.
2104 struct spi_controller
*__spi_alloc_controller(struct device
*dev
,
2105 unsigned int size
, bool slave
)
2107 struct spi_controller
*ctlr
;
2112 ctlr
= kzalloc(size
+ sizeof(*ctlr
), GFP_KERNEL
);
2116 device_initialize(&ctlr
->dev
);
2118 ctlr
->num_chipselect
= 1;
2119 ctlr
->slave
= slave
;
2120 if (IS_ENABLED(CONFIG_SPI_SLAVE
) && slave
)
2121 ctlr
->dev
.class = &spi_slave_class
;
2123 ctlr
->dev
.class = &spi_master_class
;
2124 ctlr
->dev
.parent
= dev
;
2125 pm_suspend_ignore_children(&ctlr
->dev
, true);
2126 spi_controller_set_devdata(ctlr
, &ctlr
[1]);
2130 EXPORT_SYMBOL_GPL(__spi_alloc_controller
);
2133 static int of_spi_register_master(struct spi_controller
*ctlr
)
2136 struct device_node
*np
= ctlr
->dev
.of_node
;
2141 nb
= of_gpio_named_count(np
, "cs-gpios");
2142 ctlr
->num_chipselect
= max_t(int, nb
, ctlr
->num_chipselect
);
2144 /* Return error only for an incorrectly formed cs-gpios property */
2145 if (nb
== 0 || nb
== -ENOENT
)
2150 cs
= devm_kcalloc(&ctlr
->dev
, ctlr
->num_chipselect
, sizeof(int),
2152 ctlr
->cs_gpios
= cs
;
2154 if (!ctlr
->cs_gpios
)
2157 for (i
= 0; i
< ctlr
->num_chipselect
; i
++)
2160 for (i
= 0; i
< nb
; i
++)
2161 cs
[i
] = of_get_named_gpio(np
, "cs-gpios", i
);
2166 static int of_spi_register_master(struct spi_controller
*ctlr
)
2173 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2174 * @ctlr: The SPI master to grab GPIO descriptors for
2176 static int spi_get_gpio_descs(struct spi_controller
*ctlr
)
2179 struct gpio_desc
**cs
;
2180 struct device
*dev
= &ctlr
->dev
;
2182 nb
= gpiod_count(dev
, "cs");
2183 ctlr
->num_chipselect
= max_t(int, nb
, ctlr
->num_chipselect
);
2185 /* No GPIOs at all is fine, else return the error */
2186 if (nb
== 0 || nb
== -ENOENT
)
2191 cs
= devm_kcalloc(dev
, ctlr
->num_chipselect
, sizeof(*cs
),
2195 ctlr
->cs_gpiods
= cs
;
2197 for (i
= 0; i
< nb
; i
++) {
2199 * Most chipselects are active low, the inverted
2200 * semantics are handled by special quirks in gpiolib,
2201 * so initializing them GPIOD_OUT_LOW here means
2202 * "unasserted", in most cases this will drive the physical
2205 cs
[i
] = devm_gpiod_get_index_optional(dev
, "cs", i
,
2208 return PTR_ERR(cs
[i
]);
2212 * If we find a CS GPIO, name it after the device and
2217 gpioname
= devm_kasprintf(dev
, GFP_KERNEL
, "%s CS%d",
2221 gpiod_set_consumer_name(cs
[i
], gpioname
);
2228 static int spi_controller_check_ops(struct spi_controller
*ctlr
)
2231 * The controller may implement only the high-level SPI-memory like
2232 * operations if it does not support regular SPI transfers, and this is
2234 * If ->mem_ops is NULL, we request that at least one of the
2235 * ->transfer_xxx() method be implemented.
2237 if (ctlr
->mem_ops
) {
2238 if (!ctlr
->mem_ops
->exec_op
)
2240 } else if (!ctlr
->transfer
&& !ctlr
->transfer_one
&&
2241 !ctlr
->transfer_one_message
) {
2249 * spi_register_controller - register SPI master or slave controller
2250 * @ctlr: initialized master, originally from spi_alloc_master() or
2252 * Context: can sleep
2254 * SPI controllers connect to their drivers using some non-SPI bus,
2255 * such as the platform bus. The final stage of probe() in that code
2256 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2258 * SPI controllers use board specific (often SOC specific) bus numbers,
2259 * and board-specific addressing for SPI devices combines those numbers
2260 * with chip select numbers. Since SPI does not directly support dynamic
2261 * device identification, boards need configuration tables telling which
2262 * chip is at which address.
2264 * This must be called from context that can sleep. It returns zero on
2265 * success, else a negative error code (dropping the controller's refcount).
2266 * After a successful return, the caller is responsible for calling
2267 * spi_unregister_controller().
2269 * Return: zero on success, else a negative error code.
2271 int spi_register_controller(struct spi_controller
*ctlr
)
2273 struct device
*dev
= ctlr
->dev
.parent
;
2274 struct boardinfo
*bi
;
2276 int id
, first_dynamic
;
2282 * Make sure all necessary hooks are implemented before registering
2283 * the SPI controller.
2285 status
= spi_controller_check_ops(ctlr
);
2289 /* even if it's just one always-selected device, there must
2290 * be at least one chipselect
2292 if (ctlr
->num_chipselect
== 0)
2294 if (ctlr
->bus_num
>= 0) {
2295 /* devices with a fixed bus num must check-in with the num */
2296 mutex_lock(&board_lock
);
2297 id
= idr_alloc(&spi_master_idr
, ctlr
, ctlr
->bus_num
,
2298 ctlr
->bus_num
+ 1, GFP_KERNEL
);
2299 mutex_unlock(&board_lock
);
2300 if (WARN(id
< 0, "couldn't get idr"))
2301 return id
== -ENOSPC
? -EBUSY
: id
;
2303 } else if (ctlr
->dev
.of_node
) {
2304 /* allocate dynamic bus number using Linux idr */
2305 id
= of_alias_get_id(ctlr
->dev
.of_node
, "spi");
2308 mutex_lock(&board_lock
);
2309 id
= idr_alloc(&spi_master_idr
, ctlr
, ctlr
->bus_num
,
2310 ctlr
->bus_num
+ 1, GFP_KERNEL
);
2311 mutex_unlock(&board_lock
);
2312 if (WARN(id
< 0, "couldn't get idr"))
2313 return id
== -ENOSPC
? -EBUSY
: id
;
2316 if (ctlr
->bus_num
< 0) {
2317 first_dynamic
= of_alias_get_highest_id("spi");
2318 if (first_dynamic
< 0)
2323 mutex_lock(&board_lock
);
2324 id
= idr_alloc(&spi_master_idr
, ctlr
, first_dynamic
,
2326 mutex_unlock(&board_lock
);
2327 if (WARN(id
< 0, "couldn't get idr"))
2331 INIT_LIST_HEAD(&ctlr
->queue
);
2332 spin_lock_init(&ctlr
->queue_lock
);
2333 spin_lock_init(&ctlr
->bus_lock_spinlock
);
2334 mutex_init(&ctlr
->bus_lock_mutex
);
2335 mutex_init(&ctlr
->io_mutex
);
2336 ctlr
->bus_lock_flag
= 0;
2337 init_completion(&ctlr
->xfer_completion
);
2338 if (!ctlr
->max_dma_len
)
2339 ctlr
->max_dma_len
= INT_MAX
;
2341 /* register the device, then userspace will see it.
2342 * registration fails if the bus ID is in use.
2344 dev_set_name(&ctlr
->dev
, "spi%u", ctlr
->bus_num
);
2346 if (!spi_controller_is_slave(ctlr
)) {
2347 if (ctlr
->use_gpio_descriptors
) {
2348 status
= spi_get_gpio_descs(ctlr
);
2352 * A controller using GPIO descriptors always
2353 * supports SPI_CS_HIGH if need be.
2355 ctlr
->mode_bits
|= SPI_CS_HIGH
;
2357 /* Legacy code path for GPIOs from DT */
2358 status
= of_spi_register_master(ctlr
);
2364 status
= device_add(&ctlr
->dev
);
2367 mutex_lock(&board_lock
);
2368 idr_remove(&spi_master_idr
, ctlr
->bus_num
);
2369 mutex_unlock(&board_lock
);
2372 dev_dbg(dev
, "registered %s %s\n",
2373 spi_controller_is_slave(ctlr
) ? "slave" : "master",
2374 dev_name(&ctlr
->dev
));
2377 * If we're using a queued driver, start the queue. Note that we don't
2378 * need the queueing logic if the driver is only supporting high-level
2379 * memory operations.
2381 if (ctlr
->transfer
) {
2382 dev_info(dev
, "controller is unqueued, this is deprecated\n");
2383 } else if (ctlr
->transfer_one
|| ctlr
->transfer_one_message
) {
2384 status
= spi_controller_initialize_queue(ctlr
);
2386 device_del(&ctlr
->dev
);
2388 mutex_lock(&board_lock
);
2389 idr_remove(&spi_master_idr
, ctlr
->bus_num
);
2390 mutex_unlock(&board_lock
);
2394 /* add statistics */
2395 spin_lock_init(&ctlr
->statistics
.lock
);
2397 mutex_lock(&board_lock
);
2398 list_add_tail(&ctlr
->list
, &spi_controller_list
);
2399 list_for_each_entry(bi
, &board_list
, list
)
2400 spi_match_controller_to_boardinfo(ctlr
, &bi
->board_info
);
2401 mutex_unlock(&board_lock
);
2403 /* Register devices from the device tree and ACPI */
2404 of_register_spi_devices(ctlr
);
2405 acpi_register_spi_devices(ctlr
);
2409 EXPORT_SYMBOL_GPL(spi_register_controller
);
2411 static void devm_spi_unregister(struct device
*dev
, void *res
)
2413 spi_unregister_controller(*(struct spi_controller
**)res
);
2417 * devm_spi_register_controller - register managed SPI master or slave
2419 * @dev: device managing SPI controller
2420 * @ctlr: initialized controller, originally from spi_alloc_master() or
2422 * Context: can sleep
2424 * Register a SPI device as with spi_register_controller() which will
2425 * automatically be unregistered and freed.
2427 * Return: zero on success, else a negative error code.
2429 int devm_spi_register_controller(struct device
*dev
,
2430 struct spi_controller
*ctlr
)
2432 struct spi_controller
**ptr
;
2435 ptr
= devres_alloc(devm_spi_unregister
, sizeof(*ptr
), GFP_KERNEL
);
2439 ret
= spi_register_controller(ctlr
);
2442 devres_add(dev
, ptr
);
2449 EXPORT_SYMBOL_GPL(devm_spi_register_controller
);
2451 static int __unregister(struct device
*dev
, void *null
)
2453 spi_unregister_device(to_spi_device(dev
));
2458 * spi_unregister_controller - unregister SPI master or slave controller
2459 * @ctlr: the controller being unregistered
2460 * Context: can sleep
2462 * This call is used only by SPI controller drivers, which are the
2463 * only ones directly touching chip registers.
2465 * This must be called from context that can sleep.
2467 * Note that this function also drops a reference to the controller.
2469 void spi_unregister_controller(struct spi_controller
*ctlr
)
2471 struct spi_controller
*found
;
2472 int id
= ctlr
->bus_num
;
2475 /* First make sure that this controller was ever added */
2476 mutex_lock(&board_lock
);
2477 found
= idr_find(&spi_master_idr
, id
);
2478 mutex_unlock(&board_lock
);
2480 if (spi_destroy_queue(ctlr
))
2481 dev_err(&ctlr
->dev
, "queue remove failed\n");
2483 mutex_lock(&board_lock
);
2484 list_del(&ctlr
->list
);
2485 mutex_unlock(&board_lock
);
2487 dummy
= device_for_each_child(&ctlr
->dev
, NULL
, __unregister
);
2488 device_unregister(&ctlr
->dev
);
2490 mutex_lock(&board_lock
);
2492 idr_remove(&spi_master_idr
, id
);
2493 mutex_unlock(&board_lock
);
2495 EXPORT_SYMBOL_GPL(spi_unregister_controller
);
2497 int spi_controller_suspend(struct spi_controller
*ctlr
)
2501 /* Basically no-ops for non-queued controllers */
2505 ret
= spi_stop_queue(ctlr
);
2507 dev_err(&ctlr
->dev
, "queue stop failed\n");
2511 EXPORT_SYMBOL_GPL(spi_controller_suspend
);
2513 int spi_controller_resume(struct spi_controller
*ctlr
)
2520 ret
= spi_start_queue(ctlr
);
2522 dev_err(&ctlr
->dev
, "queue restart failed\n");
2526 EXPORT_SYMBOL_GPL(spi_controller_resume
);
2528 static int __spi_controller_match(struct device
*dev
, const void *data
)
2530 struct spi_controller
*ctlr
;
2531 const u16
*bus_num
= data
;
2533 ctlr
= container_of(dev
, struct spi_controller
, dev
);
2534 return ctlr
->bus_num
== *bus_num
;
2538 * spi_busnum_to_master - look up master associated with bus_num
2539 * @bus_num: the master's bus number
2540 * Context: can sleep
2542 * This call may be used with devices that are registered after
2543 * arch init time. It returns a refcounted pointer to the relevant
2544 * spi_controller (which the caller must release), or NULL if there is
2545 * no such master registered.
2547 * Return: the SPI master structure on success, else NULL.
2549 struct spi_controller
*spi_busnum_to_master(u16 bus_num
)
2552 struct spi_controller
*ctlr
= NULL
;
2554 dev
= class_find_device(&spi_master_class
, NULL
, &bus_num
,
2555 __spi_controller_match
);
2557 ctlr
= container_of(dev
, struct spi_controller
, dev
);
2558 /* reference got in class_find_device */
2561 EXPORT_SYMBOL_GPL(spi_busnum_to_master
);
2563 /*-------------------------------------------------------------------------*/
2565 /* Core methods for SPI resource management */
2568 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2569 * during the processing of a spi_message while using
2571 * @spi: the spi device for which we allocate memory
2572 * @release: the release code to execute for this resource
2573 * @size: size to alloc and return
2574 * @gfp: GFP allocation flags
2576 * Return: the pointer to the allocated data
2578 * This may get enhanced in the future to allocate from a memory pool
2579 * of the @spi_device or @spi_controller to avoid repeated allocations.
2581 void *spi_res_alloc(struct spi_device
*spi
,
2582 spi_res_release_t release
,
2583 size_t size
, gfp_t gfp
)
2585 struct spi_res
*sres
;
2587 sres
= kzalloc(sizeof(*sres
) + size
, gfp
);
2591 INIT_LIST_HEAD(&sres
->entry
);
2592 sres
->release
= release
;
2596 EXPORT_SYMBOL_GPL(spi_res_alloc
);
2599 * spi_res_free - free an spi resource
2600 * @res: pointer to the custom data of a resource
2603 void spi_res_free(void *res
)
2605 struct spi_res
*sres
= container_of(res
, struct spi_res
, data
);
2610 WARN_ON(!list_empty(&sres
->entry
));
2613 EXPORT_SYMBOL_GPL(spi_res_free
);
2616 * spi_res_add - add a spi_res to the spi_message
2617 * @message: the spi message
2618 * @res: the spi_resource
2620 void spi_res_add(struct spi_message
*message
, void *res
)
2622 struct spi_res
*sres
= container_of(res
, struct spi_res
, data
);
2624 WARN_ON(!list_empty(&sres
->entry
));
2625 list_add_tail(&sres
->entry
, &message
->resources
);
2627 EXPORT_SYMBOL_GPL(spi_res_add
);
2630 * spi_res_release - release all spi resources for this message
2631 * @ctlr: the @spi_controller
2632 * @message: the @spi_message
2634 void spi_res_release(struct spi_controller
*ctlr
, struct spi_message
*message
)
2636 struct spi_res
*res
;
2638 while (!list_empty(&message
->resources
)) {
2639 res
= list_last_entry(&message
->resources
,
2640 struct spi_res
, entry
);
2643 res
->release(ctlr
, message
, res
->data
);
2645 list_del(&res
->entry
);
2650 EXPORT_SYMBOL_GPL(spi_res_release
);
2652 /*-------------------------------------------------------------------------*/
2654 /* Core methods for spi_message alterations */
2656 static void __spi_replace_transfers_release(struct spi_controller
*ctlr
,
2657 struct spi_message
*msg
,
2660 struct spi_replaced_transfers
*rxfer
= res
;
2663 /* call extra callback if requested */
2665 rxfer
->release(ctlr
, msg
, res
);
2667 /* insert replaced transfers back into the message */
2668 list_splice(&rxfer
->replaced_transfers
, rxfer
->replaced_after
);
2670 /* remove the formerly inserted entries */
2671 for (i
= 0; i
< rxfer
->inserted
; i
++)
2672 list_del(&rxfer
->inserted_transfers
[i
].transfer_list
);
2676 * spi_replace_transfers - replace transfers with several transfers
2677 * and register change with spi_message.resources
2678 * @msg: the spi_message we work upon
2679 * @xfer_first: the first spi_transfer we want to replace
2680 * @remove: number of transfers to remove
2681 * @insert: the number of transfers we want to insert instead
2682 * @release: extra release code necessary in some circumstances
2683 * @extradatasize: extra data to allocate (with alignment guarantees
2684 * of struct @spi_transfer)
2687 * Returns: pointer to @spi_replaced_transfers,
2688 * PTR_ERR(...) in case of errors.
2690 struct spi_replaced_transfers
*spi_replace_transfers(
2691 struct spi_message
*msg
,
2692 struct spi_transfer
*xfer_first
,
2695 spi_replaced_release_t release
,
2696 size_t extradatasize
,
2699 struct spi_replaced_transfers
*rxfer
;
2700 struct spi_transfer
*xfer
;
2703 /* allocate the structure using spi_res */
2704 rxfer
= spi_res_alloc(msg
->spi
, __spi_replace_transfers_release
,
2705 insert
* sizeof(struct spi_transfer
)
2706 + sizeof(struct spi_replaced_transfers
)
2710 return ERR_PTR(-ENOMEM
);
2712 /* the release code to invoke before running the generic release */
2713 rxfer
->release
= release
;
2715 /* assign extradata */
2718 &rxfer
->inserted_transfers
[insert
];
2720 /* init the replaced_transfers list */
2721 INIT_LIST_HEAD(&rxfer
->replaced_transfers
);
2723 /* assign the list_entry after which we should reinsert
2724 * the @replaced_transfers - it may be spi_message.messages!
2726 rxfer
->replaced_after
= xfer_first
->transfer_list
.prev
;
2728 /* remove the requested number of transfers */
2729 for (i
= 0; i
< remove
; i
++) {
2730 /* if the entry after replaced_after it is msg->transfers
2731 * then we have been requested to remove more transfers
2732 * than are in the list
2734 if (rxfer
->replaced_after
->next
== &msg
->transfers
) {
2735 dev_err(&msg
->spi
->dev
,
2736 "requested to remove more spi_transfers than are available\n");
2737 /* insert replaced transfers back into the message */
2738 list_splice(&rxfer
->replaced_transfers
,
2739 rxfer
->replaced_after
);
2741 /* free the spi_replace_transfer structure */
2742 spi_res_free(rxfer
);
2744 /* and return with an error */
2745 return ERR_PTR(-EINVAL
);
2748 /* remove the entry after replaced_after from list of
2749 * transfers and add it to list of replaced_transfers
2751 list_move_tail(rxfer
->replaced_after
->next
,
2752 &rxfer
->replaced_transfers
);
2755 /* create copy of the given xfer with identical settings
2756 * based on the first transfer to get removed
2758 for (i
= 0; i
< insert
; i
++) {
2759 /* we need to run in reverse order */
2760 xfer
= &rxfer
->inserted_transfers
[insert
- 1 - i
];
2762 /* copy all spi_transfer data */
2763 memcpy(xfer
, xfer_first
, sizeof(*xfer
));
2766 list_add(&xfer
->transfer_list
, rxfer
->replaced_after
);
2768 /* clear cs_change and delay_usecs for all but the last */
2770 xfer
->cs_change
= false;
2771 xfer
->delay_usecs
= 0;
2775 /* set up inserted */
2776 rxfer
->inserted
= insert
;
2778 /* and register it with spi_res/spi_message */
2779 spi_res_add(msg
, rxfer
);
2783 EXPORT_SYMBOL_GPL(spi_replace_transfers
);
2785 static int __spi_split_transfer_maxsize(struct spi_controller
*ctlr
,
2786 struct spi_message
*msg
,
2787 struct spi_transfer
**xferp
,
2791 struct spi_transfer
*xfer
= *xferp
, *xfers
;
2792 struct spi_replaced_transfers
*srt
;
2796 /* calculate how many we have to replace */
2797 count
= DIV_ROUND_UP(xfer
->len
, maxsize
);
2799 /* create replacement */
2800 srt
= spi_replace_transfers(msg
, xfer
, 1, count
, NULL
, 0, gfp
);
2802 return PTR_ERR(srt
);
2803 xfers
= srt
->inserted_transfers
;
2805 /* now handle each of those newly inserted spi_transfers
2806 * note that the replacements spi_transfers all are preset
2807 * to the same values as *xferp, so tx_buf, rx_buf and len
2808 * are all identical (as well as most others)
2809 * so we just have to fix up len and the pointers.
2811 * this also includes support for the depreciated
2812 * spi_message.is_dma_mapped interface
2815 /* the first transfer just needs the length modified, so we
2816 * run it outside the loop
2818 xfers
[0].len
= min_t(size_t, maxsize
, xfer
[0].len
);
2820 /* all the others need rx_buf/tx_buf also set */
2821 for (i
= 1, offset
= maxsize
; i
< count
; offset
+= maxsize
, i
++) {
2822 /* update rx_buf, tx_buf and dma */
2823 if (xfers
[i
].rx_buf
)
2824 xfers
[i
].rx_buf
+= offset
;
2825 if (xfers
[i
].rx_dma
)
2826 xfers
[i
].rx_dma
+= offset
;
2827 if (xfers
[i
].tx_buf
)
2828 xfers
[i
].tx_buf
+= offset
;
2829 if (xfers
[i
].tx_dma
)
2830 xfers
[i
].tx_dma
+= offset
;
2833 xfers
[i
].len
= min(maxsize
, xfers
[i
].len
- offset
);
2836 /* we set up xferp to the last entry we have inserted,
2837 * so that we skip those already split transfers
2839 *xferp
= &xfers
[count
- 1];
2841 /* increment statistics counters */
2842 SPI_STATISTICS_INCREMENT_FIELD(&ctlr
->statistics
,
2843 transfers_split_maxsize
);
2844 SPI_STATISTICS_INCREMENT_FIELD(&msg
->spi
->statistics
,
2845 transfers_split_maxsize
);
2851 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2852 * when an individual transfer exceeds a
2854 * @ctlr: the @spi_controller for this transfer
2855 * @msg: the @spi_message to transform
2856 * @maxsize: the maximum when to apply this
2857 * @gfp: GFP allocation flags
2859 * Return: status of transformation
2861 int spi_split_transfers_maxsize(struct spi_controller
*ctlr
,
2862 struct spi_message
*msg
,
2866 struct spi_transfer
*xfer
;
2869 /* iterate over the transfer_list,
2870 * but note that xfer is advanced to the last transfer inserted
2871 * to avoid checking sizes again unnecessarily (also xfer does
2872 * potentiall belong to a different list by the time the
2873 * replacement has happened
2875 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
2876 if (xfer
->len
> maxsize
) {
2877 ret
= __spi_split_transfer_maxsize(ctlr
, msg
, &xfer
,
2886 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize
);
2888 /*-------------------------------------------------------------------------*/
2890 /* Core methods for SPI controller protocol drivers. Some of the
2891 * other core methods are currently defined as inline functions.
2894 static int __spi_validate_bits_per_word(struct spi_controller
*ctlr
,
2897 if (ctlr
->bits_per_word_mask
) {
2898 /* Only 32 bits fit in the mask */
2899 if (bits_per_word
> 32)
2901 if (!(ctlr
->bits_per_word_mask
& SPI_BPW_MASK(bits_per_word
)))
2909 * spi_setup - setup SPI mode and clock rate
2910 * @spi: the device whose settings are being modified
2911 * Context: can sleep, and no requests are queued to the device
2913 * SPI protocol drivers may need to update the transfer mode if the
2914 * device doesn't work with its default. They may likewise need
2915 * to update clock rates or word sizes from initial values. This function
2916 * changes those settings, and must be called from a context that can sleep.
2917 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2918 * effect the next time the device is selected and data is transferred to
2919 * or from it. When this function returns, the spi device is deselected.
2921 * Note that this call will fail if the protocol driver specifies an option
2922 * that the underlying controller or its driver does not support. For
2923 * example, not all hardware supports wire transfers using nine bit words,
2924 * LSB-first wire encoding, or active-high chipselects.
2926 * Return: zero on success, else a negative error code.
2928 int spi_setup(struct spi_device
*spi
)
2930 unsigned bad_bits
, ugly_bits
;
2933 /* check mode to prevent that DUAL and QUAD set at the same time
2935 if (((spi
->mode
& SPI_TX_DUAL
) && (spi
->mode
& SPI_TX_QUAD
)) ||
2936 ((spi
->mode
& SPI_RX_DUAL
) && (spi
->mode
& SPI_RX_QUAD
))) {
2938 "setup: can not select dual and quad at the same time\n");
2941 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2943 if ((spi
->mode
& SPI_3WIRE
) && (spi
->mode
&
2944 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_TX_OCTAL
|
2945 SPI_RX_DUAL
| SPI_RX_QUAD
| SPI_RX_OCTAL
)))
2947 /* help drivers fail *cleanly* when they need options
2948 * that aren't supported with their current controller
2949 * SPI_CS_WORD has a fallback software implementation,
2950 * so it is ignored here.
2952 bad_bits
= spi
->mode
& ~(spi
->controller
->mode_bits
| SPI_CS_WORD
);
2953 /* nothing prevents from working with active-high CS in case if it
2954 * is driven by GPIO.
2956 if (gpio_is_valid(spi
->cs_gpio
))
2957 bad_bits
&= ~SPI_CS_HIGH
;
2958 ugly_bits
= bad_bits
&
2959 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_TX_OCTAL
|
2960 SPI_RX_DUAL
| SPI_RX_QUAD
| SPI_RX_OCTAL
);
2963 "setup: ignoring unsupported mode bits %x\n",
2965 spi
->mode
&= ~ugly_bits
;
2966 bad_bits
&= ~ugly_bits
;
2969 dev_err(&spi
->dev
, "setup: unsupported mode bits %x\n",
2974 if (!spi
->bits_per_word
)
2975 spi
->bits_per_word
= 8;
2977 status
= __spi_validate_bits_per_word(spi
->controller
,
2978 spi
->bits_per_word
);
2982 if (!spi
->max_speed_hz
)
2983 spi
->max_speed_hz
= spi
->controller
->max_speed_hz
;
2985 if (spi
->controller
->setup
)
2986 status
= spi
->controller
->setup(spi
);
2988 spi_set_cs(spi
, false);
2990 dev_dbg(&spi
->dev
, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2991 (int) (spi
->mode
& (SPI_CPOL
| SPI_CPHA
)),
2992 (spi
->mode
& SPI_CS_HIGH
) ? "cs_high, " : "",
2993 (spi
->mode
& SPI_LSB_FIRST
) ? "lsb, " : "",
2994 (spi
->mode
& SPI_3WIRE
) ? "3wire, " : "",
2995 (spi
->mode
& SPI_LOOP
) ? "loopback, " : "",
2996 spi
->bits_per_word
, spi
->max_speed_hz
,
3001 EXPORT_SYMBOL_GPL(spi_setup
);
3004 * spi_set_cs_timing - configure CS setup, hold, and inactive delays
3005 * @spi: the device that requires specific CS timing configuration
3006 * @setup: CS setup time in terms of clock count
3007 * @hold: CS hold time in terms of clock count
3008 * @inactive_dly: CS inactive delay between transfers in terms of clock count
3010 void spi_set_cs_timing(struct spi_device
*spi
, u8 setup
, u8 hold
,
3013 if (spi
->controller
->set_cs_timing
)
3014 spi
->controller
->set_cs_timing(spi
, setup
, hold
, inactive_dly
);
3016 EXPORT_SYMBOL_GPL(spi_set_cs_timing
);
3018 static int __spi_validate(struct spi_device
*spi
, struct spi_message
*message
)
3020 struct spi_controller
*ctlr
= spi
->controller
;
3021 struct spi_transfer
*xfer
;
3024 if (list_empty(&message
->transfers
))
3027 /* If an SPI controller does not support toggling the CS line on each
3028 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3029 * for the CS line, we can emulate the CS-per-word hardware function by
3030 * splitting transfers into one-word transfers and ensuring that
3031 * cs_change is set for each transfer.
3033 if ((spi
->mode
& SPI_CS_WORD
) && (!(ctlr
->mode_bits
& SPI_CS_WORD
) ||
3035 gpio_is_valid(spi
->cs_gpio
))) {
3039 maxsize
= (spi
->bits_per_word
+ 7) / 8;
3041 /* spi_split_transfers_maxsize() requires message->spi */
3044 ret
= spi_split_transfers_maxsize(ctlr
, message
, maxsize
,
3049 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
3050 /* don't change cs_change on the last entry in the list */
3051 if (list_is_last(&xfer
->transfer_list
, &message
->transfers
))
3053 xfer
->cs_change
= 1;
3057 /* Half-duplex links include original MicroWire, and ones with
3058 * only one data pin like SPI_3WIRE (switches direction) or where
3059 * either MOSI or MISO is missing. They can also be caused by
3060 * software limitations.
3062 if ((ctlr
->flags
& SPI_CONTROLLER_HALF_DUPLEX
) ||
3063 (spi
->mode
& SPI_3WIRE
)) {
3064 unsigned flags
= ctlr
->flags
;
3066 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
3067 if (xfer
->rx_buf
&& xfer
->tx_buf
)
3069 if ((flags
& SPI_CONTROLLER_NO_TX
) && xfer
->tx_buf
)
3071 if ((flags
& SPI_CONTROLLER_NO_RX
) && xfer
->rx_buf
)
3077 * Set transfer bits_per_word and max speed as spi device default if
3078 * it is not set for this transfer.
3079 * Set transfer tx_nbits and rx_nbits as single transfer default
3080 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3081 * Ensure transfer word_delay is at least as long as that required by
3084 message
->frame_length
= 0;
3085 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
3086 message
->frame_length
+= xfer
->len
;
3087 if (!xfer
->bits_per_word
)
3088 xfer
->bits_per_word
= spi
->bits_per_word
;
3090 if (!xfer
->speed_hz
)
3091 xfer
->speed_hz
= spi
->max_speed_hz
;
3093 if (ctlr
->max_speed_hz
&& xfer
->speed_hz
> ctlr
->max_speed_hz
)
3094 xfer
->speed_hz
= ctlr
->max_speed_hz
;
3096 if (__spi_validate_bits_per_word(ctlr
, xfer
->bits_per_word
))
3100 * SPI transfer length should be multiple of SPI word size
3101 * where SPI word size should be power-of-two multiple
3103 if (xfer
->bits_per_word
<= 8)
3105 else if (xfer
->bits_per_word
<= 16)
3110 /* No partial transfers accepted */
3111 if (xfer
->len
% w_size
)
3114 if (xfer
->speed_hz
&& ctlr
->min_speed_hz
&&
3115 xfer
->speed_hz
< ctlr
->min_speed_hz
)
3118 if (xfer
->tx_buf
&& !xfer
->tx_nbits
)
3119 xfer
->tx_nbits
= SPI_NBITS_SINGLE
;
3120 if (xfer
->rx_buf
&& !xfer
->rx_nbits
)
3121 xfer
->rx_nbits
= SPI_NBITS_SINGLE
;
3122 /* check transfer tx/rx_nbits:
3123 * 1. check the value matches one of single, dual and quad
3124 * 2. check tx/rx_nbits match the mode in spi_device
3127 if (xfer
->tx_nbits
!= SPI_NBITS_SINGLE
&&
3128 xfer
->tx_nbits
!= SPI_NBITS_DUAL
&&
3129 xfer
->tx_nbits
!= SPI_NBITS_QUAD
)
3131 if ((xfer
->tx_nbits
== SPI_NBITS_DUAL
) &&
3132 !(spi
->mode
& (SPI_TX_DUAL
| SPI_TX_QUAD
)))
3134 if ((xfer
->tx_nbits
== SPI_NBITS_QUAD
) &&
3135 !(spi
->mode
& SPI_TX_QUAD
))
3138 /* check transfer rx_nbits */
3140 if (xfer
->rx_nbits
!= SPI_NBITS_SINGLE
&&
3141 xfer
->rx_nbits
!= SPI_NBITS_DUAL
&&
3142 xfer
->rx_nbits
!= SPI_NBITS_QUAD
)
3144 if ((xfer
->rx_nbits
== SPI_NBITS_DUAL
) &&
3145 !(spi
->mode
& (SPI_RX_DUAL
| SPI_RX_QUAD
)))
3147 if ((xfer
->rx_nbits
== SPI_NBITS_QUAD
) &&
3148 !(spi
->mode
& SPI_RX_QUAD
))
3152 if (xfer
->word_delay_usecs
< spi
->word_delay_usecs
)
3153 xfer
->word_delay_usecs
= spi
->word_delay_usecs
;
3156 message
->status
= -EINPROGRESS
;
3161 static int __spi_async(struct spi_device
*spi
, struct spi_message
*message
)
3163 struct spi_controller
*ctlr
= spi
->controller
;
3166 * Some controllers do not support doing regular SPI transfers. Return
3167 * ENOTSUPP when this is the case.
3169 if (!ctlr
->transfer
)
3174 SPI_STATISTICS_INCREMENT_FIELD(&ctlr
->statistics
, spi_async
);
3175 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
, spi_async
);
3177 trace_spi_message_submit(message
);
3179 return ctlr
->transfer(spi
, message
);
3183 * spi_async - asynchronous SPI transfer
3184 * @spi: device with which data will be exchanged
3185 * @message: describes the data transfers, including completion callback
3186 * Context: any (irqs may be blocked, etc)
3188 * This call may be used in_irq and other contexts which can't sleep,
3189 * as well as from task contexts which can sleep.
3191 * The completion callback is invoked in a context which can't sleep.
3192 * Before that invocation, the value of message->status is undefined.
3193 * When the callback is issued, message->status holds either zero (to
3194 * indicate complete success) or a negative error code. After that
3195 * callback returns, the driver which issued the transfer request may
3196 * deallocate the associated memory; it's no longer in use by any SPI
3197 * core or controller driver code.
3199 * Note that although all messages to a spi_device are handled in
3200 * FIFO order, messages may go to different devices in other orders.
3201 * Some device might be higher priority, or have various "hard" access
3202 * time requirements, for example.
3204 * On detection of any fault during the transfer, processing of
3205 * the entire message is aborted, and the device is deselected.
3206 * Until returning from the associated message completion callback,
3207 * no other spi_message queued to that device will be processed.
3208 * (This rule applies equally to all the synchronous transfer calls,
3209 * which are wrappers around this core asynchronous primitive.)
3211 * Return: zero on success, else a negative error code.
3213 int spi_async(struct spi_device
*spi
, struct spi_message
*message
)
3215 struct spi_controller
*ctlr
= spi
->controller
;
3217 unsigned long flags
;
3219 ret
= __spi_validate(spi
, message
);
3223 spin_lock_irqsave(&ctlr
->bus_lock_spinlock
, flags
);
3225 if (ctlr
->bus_lock_flag
)
3228 ret
= __spi_async(spi
, message
);
3230 spin_unlock_irqrestore(&ctlr
->bus_lock_spinlock
, flags
);
3234 EXPORT_SYMBOL_GPL(spi_async
);
3237 * spi_async_locked - version of spi_async with exclusive bus usage
3238 * @spi: device with which data will be exchanged
3239 * @message: describes the data transfers, including completion callback
3240 * Context: any (irqs may be blocked, etc)
3242 * This call may be used in_irq and other contexts which can't sleep,
3243 * as well as from task contexts which can sleep.
3245 * The completion callback is invoked in a context which can't sleep.
3246 * Before that invocation, the value of message->status is undefined.
3247 * When the callback is issued, message->status holds either zero (to
3248 * indicate complete success) or a negative error code. After that
3249 * callback returns, the driver which issued the transfer request may
3250 * deallocate the associated memory; it's no longer in use by any SPI
3251 * core or controller driver code.
3253 * Note that although all messages to a spi_device are handled in
3254 * FIFO order, messages may go to different devices in other orders.
3255 * Some device might be higher priority, or have various "hard" access
3256 * time requirements, for example.
3258 * On detection of any fault during the transfer, processing of
3259 * the entire message is aborted, and the device is deselected.
3260 * Until returning from the associated message completion callback,
3261 * no other spi_message queued to that device will be processed.
3262 * (This rule applies equally to all the synchronous transfer calls,
3263 * which are wrappers around this core asynchronous primitive.)
3265 * Return: zero on success, else a negative error code.
3267 int spi_async_locked(struct spi_device
*spi
, struct spi_message
*message
)
3269 struct spi_controller
*ctlr
= spi
->controller
;
3271 unsigned long flags
;
3273 ret
= __spi_validate(spi
, message
);
3277 spin_lock_irqsave(&ctlr
->bus_lock_spinlock
, flags
);
3279 ret
= __spi_async(spi
, message
);
3281 spin_unlock_irqrestore(&ctlr
->bus_lock_spinlock
, flags
);
3286 EXPORT_SYMBOL_GPL(spi_async_locked
);
3288 /*-------------------------------------------------------------------------*/
3290 /* Utility methods for SPI protocol drivers, layered on
3291 * top of the core. Some other utility methods are defined as
3295 static void spi_complete(void *arg
)
3300 static int __spi_sync(struct spi_device
*spi
, struct spi_message
*message
)
3302 DECLARE_COMPLETION_ONSTACK(done
);
3304 struct spi_controller
*ctlr
= spi
->controller
;
3305 unsigned long flags
;
3307 status
= __spi_validate(spi
, message
);
3311 message
->complete
= spi_complete
;
3312 message
->context
= &done
;
3315 SPI_STATISTICS_INCREMENT_FIELD(&ctlr
->statistics
, spi_sync
);
3316 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
, spi_sync
);
3318 /* If we're not using the legacy transfer method then we will
3319 * try to transfer in the calling context so special case.
3320 * This code would be less tricky if we could remove the
3321 * support for driver implemented message queues.
3323 if (ctlr
->transfer
== spi_queued_transfer
) {
3324 spin_lock_irqsave(&ctlr
->bus_lock_spinlock
, flags
);
3326 trace_spi_message_submit(message
);
3328 status
= __spi_queued_transfer(spi
, message
, false);
3330 spin_unlock_irqrestore(&ctlr
->bus_lock_spinlock
, flags
);
3332 status
= spi_async_locked(spi
, message
);
3336 /* Push out the messages in the calling context if we
3339 if (ctlr
->transfer
== spi_queued_transfer
) {
3340 SPI_STATISTICS_INCREMENT_FIELD(&ctlr
->statistics
,
3341 spi_sync_immediate
);
3342 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
,
3343 spi_sync_immediate
);
3344 __spi_pump_messages(ctlr
, false);
3347 wait_for_completion(&done
);
3348 status
= message
->status
;
3350 message
->context
= NULL
;
3355 * spi_sync - blocking/synchronous SPI data transfers
3356 * @spi: device with which data will be exchanged
3357 * @message: describes the data transfers
3358 * Context: can sleep
3360 * This call may only be used from a context that may sleep. The sleep
3361 * is non-interruptible, and has no timeout. Low-overhead controller
3362 * drivers may DMA directly into and out of the message buffers.
3364 * Note that the SPI device's chip select is active during the message,
3365 * and then is normally disabled between messages. Drivers for some
3366 * frequently-used devices may want to minimize costs of selecting a chip,
3367 * by leaving it selected in anticipation that the next message will go
3368 * to the same chip. (That may increase power usage.)
3370 * Also, the caller is guaranteeing that the memory associated with the
3371 * message will not be freed before this call returns.
3373 * Return: zero on success, else a negative error code.
3375 int spi_sync(struct spi_device
*spi
, struct spi_message
*message
)
3379 mutex_lock(&spi
->controller
->bus_lock_mutex
);
3380 ret
= __spi_sync(spi
, message
);
3381 mutex_unlock(&spi
->controller
->bus_lock_mutex
);
3385 EXPORT_SYMBOL_GPL(spi_sync
);
3388 * spi_sync_locked - version of spi_sync with exclusive bus usage
3389 * @spi: device with which data will be exchanged
3390 * @message: describes the data transfers
3391 * Context: can sleep
3393 * This call may only be used from a context that may sleep. The sleep
3394 * is non-interruptible, and has no timeout. Low-overhead controller
3395 * drivers may DMA directly into and out of the message buffers.
3397 * This call should be used by drivers that require exclusive access to the
3398 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3399 * be released by a spi_bus_unlock call when the exclusive access is over.
3401 * Return: zero on success, else a negative error code.
3403 int spi_sync_locked(struct spi_device
*spi
, struct spi_message
*message
)
3405 return __spi_sync(spi
, message
);
3407 EXPORT_SYMBOL_GPL(spi_sync_locked
);
3410 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3411 * @ctlr: SPI bus master that should be locked for exclusive bus access
3412 * Context: can sleep
3414 * This call may only be used from a context that may sleep. The sleep
3415 * is non-interruptible, and has no timeout.
3417 * This call should be used by drivers that require exclusive access to the
3418 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3419 * exclusive access is over. Data transfer must be done by spi_sync_locked
3420 * and spi_async_locked calls when the SPI bus lock is held.
3422 * Return: always zero.
3424 int spi_bus_lock(struct spi_controller
*ctlr
)
3426 unsigned long flags
;
3428 mutex_lock(&ctlr
->bus_lock_mutex
);
3430 spin_lock_irqsave(&ctlr
->bus_lock_spinlock
, flags
);
3431 ctlr
->bus_lock_flag
= 1;
3432 spin_unlock_irqrestore(&ctlr
->bus_lock_spinlock
, flags
);
3434 /* mutex remains locked until spi_bus_unlock is called */
3438 EXPORT_SYMBOL_GPL(spi_bus_lock
);
3441 * spi_bus_unlock - release the lock for exclusive SPI bus usage
3442 * @ctlr: SPI bus master that was locked for exclusive bus access
3443 * Context: can sleep
3445 * This call may only be used from a context that may sleep. The sleep
3446 * is non-interruptible, and has no timeout.
3448 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3451 * Return: always zero.
3453 int spi_bus_unlock(struct spi_controller
*ctlr
)
3455 ctlr
->bus_lock_flag
= 0;
3457 mutex_unlock(&ctlr
->bus_lock_mutex
);
3461 EXPORT_SYMBOL_GPL(spi_bus_unlock
);
3463 /* portable code must never pass more than 32 bytes */
3464 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3469 * spi_write_then_read - SPI synchronous write followed by read
3470 * @spi: device with which data will be exchanged
3471 * @txbuf: data to be written (need not be dma-safe)
3472 * @n_tx: size of txbuf, in bytes
3473 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3474 * @n_rx: size of rxbuf, in bytes
3475 * Context: can sleep
3477 * This performs a half duplex MicroWire style transaction with the
3478 * device, sending txbuf and then reading rxbuf. The return value
3479 * is zero for success, else a negative errno status code.
3480 * This call may only be used from a context that may sleep.
3482 * Parameters to this routine are always copied using a small buffer;
3483 * portable code should never use this for more than 32 bytes.
3484 * Performance-sensitive or bulk transfer code should instead use
3485 * spi_{async,sync}() calls with dma-safe buffers.
3487 * Return: zero on success, else a negative error code.
3489 int spi_write_then_read(struct spi_device
*spi
,
3490 const void *txbuf
, unsigned n_tx
,
3491 void *rxbuf
, unsigned n_rx
)
3493 static DEFINE_MUTEX(lock
);
3496 struct spi_message message
;
3497 struct spi_transfer x
[2];
3500 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3501 * copying here, (as a pure convenience thing), but we can
3502 * keep heap costs out of the hot path unless someone else is
3503 * using the pre-allocated buffer or the transfer is too large.
3505 if ((n_tx
+ n_rx
) > SPI_BUFSIZ
|| !mutex_trylock(&lock
)) {
3506 local_buf
= kmalloc(max((unsigned)SPI_BUFSIZ
, n_tx
+ n_rx
),
3507 GFP_KERNEL
| GFP_DMA
);
3514 spi_message_init(&message
);
3515 memset(x
, 0, sizeof(x
));
3518 spi_message_add_tail(&x
[0], &message
);
3522 spi_message_add_tail(&x
[1], &message
);
3525 memcpy(local_buf
, txbuf
, n_tx
);
3526 x
[0].tx_buf
= local_buf
;
3527 x
[1].rx_buf
= local_buf
+ n_tx
;
3530 status
= spi_sync(spi
, &message
);
3532 memcpy(rxbuf
, x
[1].rx_buf
, n_rx
);
3534 if (x
[0].tx_buf
== buf
)
3535 mutex_unlock(&lock
);
3541 EXPORT_SYMBOL_GPL(spi_write_then_read
);
3543 /*-------------------------------------------------------------------------*/
3545 #if IS_ENABLED(CONFIG_OF)
3546 static int __spi_of_device_match(struct device
*dev
, void *data
)
3548 return dev
->of_node
== data
;
3551 /* must call put_device() when done with returned spi_device device */
3552 struct spi_device
*of_find_spi_device_by_node(struct device_node
*node
)
3554 struct device
*dev
= bus_find_device(&spi_bus_type
, NULL
, node
,
3555 __spi_of_device_match
);
3556 return dev
? to_spi_device(dev
) : NULL
;
3558 EXPORT_SYMBOL_GPL(of_find_spi_device_by_node
);
3559 #endif /* IS_ENABLED(CONFIG_OF) */
3561 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
3562 static int __spi_of_controller_match(struct device
*dev
, const void *data
)
3564 return dev
->of_node
== data
;
3567 /* the spi controllers are not using spi_bus, so we find it with another way */
3568 static struct spi_controller
*of_find_spi_controller_by_node(struct device_node
*node
)
3572 dev
= class_find_device(&spi_master_class
, NULL
, node
,
3573 __spi_of_controller_match
);
3574 if (!dev
&& IS_ENABLED(CONFIG_SPI_SLAVE
))
3575 dev
= class_find_device(&spi_slave_class
, NULL
, node
,
3576 __spi_of_controller_match
);
3580 /* reference got in class_find_device */
3581 return container_of(dev
, struct spi_controller
, dev
);
3584 static int of_spi_notify(struct notifier_block
*nb
, unsigned long action
,
3587 struct of_reconfig_data
*rd
= arg
;
3588 struct spi_controller
*ctlr
;
3589 struct spi_device
*spi
;
3591 switch (of_reconfig_get_state_change(action
, arg
)) {
3592 case OF_RECONFIG_CHANGE_ADD
:
3593 ctlr
= of_find_spi_controller_by_node(rd
->dn
->parent
);
3595 return NOTIFY_OK
; /* not for us */
3597 if (of_node_test_and_set_flag(rd
->dn
, OF_POPULATED
)) {
3598 put_device(&ctlr
->dev
);
3602 spi
= of_register_spi_device(ctlr
, rd
->dn
);
3603 put_device(&ctlr
->dev
);
3606 pr_err("%s: failed to create for '%pOF'\n",
3608 of_node_clear_flag(rd
->dn
, OF_POPULATED
);
3609 return notifier_from_errno(PTR_ERR(spi
));
3613 case OF_RECONFIG_CHANGE_REMOVE
:
3614 /* already depopulated? */
3615 if (!of_node_check_flag(rd
->dn
, OF_POPULATED
))
3618 /* find our device by node */
3619 spi
= of_find_spi_device_by_node(rd
->dn
);
3621 return NOTIFY_OK
; /* no? not meant for us */
3623 /* unregister takes one ref away */
3624 spi_unregister_device(spi
);
3626 /* and put the reference of the find */
3627 put_device(&spi
->dev
);
3634 static struct notifier_block spi_of_notifier
= {
3635 .notifier_call
= of_spi_notify
,
3637 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3638 extern struct notifier_block spi_of_notifier
;
3639 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3641 #if IS_ENABLED(CONFIG_ACPI)
3642 static int spi_acpi_controller_match(struct device
*dev
, const void *data
)
3644 return ACPI_COMPANION(dev
->parent
) == data
;
3647 static int spi_acpi_device_match(struct device
*dev
, void *data
)
3649 return ACPI_COMPANION(dev
) == data
;
3652 static struct spi_controller
*acpi_spi_find_controller_by_adev(struct acpi_device
*adev
)
3656 dev
= class_find_device(&spi_master_class
, NULL
, adev
,
3657 spi_acpi_controller_match
);
3658 if (!dev
&& IS_ENABLED(CONFIG_SPI_SLAVE
))
3659 dev
= class_find_device(&spi_slave_class
, NULL
, adev
,
3660 spi_acpi_controller_match
);
3664 return container_of(dev
, struct spi_controller
, dev
);
3667 static struct spi_device
*acpi_spi_find_device_by_adev(struct acpi_device
*adev
)
3671 dev
= bus_find_device(&spi_bus_type
, NULL
, adev
, spi_acpi_device_match
);
3673 return dev
? to_spi_device(dev
) : NULL
;
3676 static int acpi_spi_notify(struct notifier_block
*nb
, unsigned long value
,
3679 struct acpi_device
*adev
= arg
;
3680 struct spi_controller
*ctlr
;
3681 struct spi_device
*spi
;
3684 case ACPI_RECONFIG_DEVICE_ADD
:
3685 ctlr
= acpi_spi_find_controller_by_adev(adev
->parent
);
3689 acpi_register_spi_device(ctlr
, adev
);
3690 put_device(&ctlr
->dev
);
3692 case ACPI_RECONFIG_DEVICE_REMOVE
:
3693 if (!acpi_device_enumerated(adev
))
3696 spi
= acpi_spi_find_device_by_adev(adev
);
3700 spi_unregister_device(spi
);
3701 put_device(&spi
->dev
);
3708 static struct notifier_block spi_acpi_notifier
= {
3709 .notifier_call
= acpi_spi_notify
,
3712 extern struct notifier_block spi_acpi_notifier
;
3715 static int __init
spi_init(void)
3719 buf
= kmalloc(SPI_BUFSIZ
, GFP_KERNEL
);
3725 status
= bus_register(&spi_bus_type
);
3729 status
= class_register(&spi_master_class
);
3733 if (IS_ENABLED(CONFIG_SPI_SLAVE
)) {
3734 status
= class_register(&spi_slave_class
);
3739 if (IS_ENABLED(CONFIG_OF_DYNAMIC
))
3740 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier
));
3741 if (IS_ENABLED(CONFIG_ACPI
))
3742 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier
));
3747 class_unregister(&spi_master_class
);
3749 bus_unregister(&spi_bus_type
);
3757 /* board_info is normally registered in arch_initcall(),
3758 * but even essential drivers wait till later
3760 * REVISIT only boardinfo really needs static linking. the rest (device and
3761 * driver registration) _could_ be dynamically linked (modular) ... costs
3762 * include needing to have boardinfo data structures be much more public.
3764 postcore_initcall(spi_init
);