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 /* Empty 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 operation 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 * Prevents addition of devices with same chip select and
480 * addition of devices below an unregistering controller.
482 static DEFINE_MUTEX(spi_add_lock
);
485 * spi_alloc_device - Allocate a new SPI device
486 * @ctlr: Controller to which device is connected
489 * Allows a driver to allocate and initialize a spi_device without
490 * registering it immediately. This allows a driver to directly
491 * fill the spi_device with device parameters before calling
492 * spi_add_device() on it.
494 * Caller is responsible to call spi_add_device() on the returned
495 * spi_device structure to add it to the SPI controller. If the caller
496 * needs to discard the spi_device without adding it, then it should
497 * call spi_dev_put() on it.
499 * Return: a pointer to the new device, or NULL.
501 struct spi_device
*spi_alloc_device(struct spi_controller
*ctlr
)
503 struct spi_device
*spi
;
505 if (!spi_controller_get(ctlr
))
508 spi
= kzalloc(sizeof(*spi
), GFP_KERNEL
);
510 spi_controller_put(ctlr
);
514 spi
->master
= spi
->controller
= ctlr
;
515 spi
->dev
.parent
= &ctlr
->dev
;
516 spi
->dev
.bus
= &spi_bus_type
;
517 spi
->dev
.release
= spidev_release
;
518 spi
->cs_gpio
= -ENOENT
;
519 spi
->mode
= ctlr
->buswidth_override_bits
;
521 spin_lock_init(&spi
->statistics
.lock
);
523 device_initialize(&spi
->dev
);
526 EXPORT_SYMBOL_GPL(spi_alloc_device
);
528 static void spi_dev_set_name(struct spi_device
*spi
)
530 struct acpi_device
*adev
= ACPI_COMPANION(&spi
->dev
);
533 dev_set_name(&spi
->dev
, "spi-%s", acpi_dev_name(adev
));
537 dev_set_name(&spi
->dev
, "%s.%u", dev_name(&spi
->controller
->dev
),
541 static int spi_dev_check(struct device
*dev
, void *data
)
543 struct spi_device
*spi
= to_spi_device(dev
);
544 struct spi_device
*new_spi
= data
;
546 if (spi
->controller
== new_spi
->controller
&&
547 spi
->chip_select
== new_spi
->chip_select
)
553 * spi_add_device - Add spi_device allocated with spi_alloc_device
554 * @spi: spi_device to register
556 * Companion function to spi_alloc_device. Devices allocated with
557 * spi_alloc_device can be added onto the spi bus with this function.
559 * Return: 0 on success; negative errno on failure
561 int spi_add_device(struct spi_device
*spi
)
563 struct spi_controller
*ctlr
= spi
->controller
;
564 struct device
*dev
= ctlr
->dev
.parent
;
567 /* Chipselects are numbered 0..max; validate. */
568 if (spi
->chip_select
>= ctlr
->num_chipselect
) {
569 dev_err(dev
, "cs%d >= max %d\n", spi
->chip_select
,
570 ctlr
->num_chipselect
);
574 /* Set the bus ID string */
575 spi_dev_set_name(spi
);
577 /* We need to make sure there's no other device with this
578 * chipselect **BEFORE** we call setup(), else we'll trash
579 * its configuration. Lock against concurrent add() calls.
581 mutex_lock(&spi_add_lock
);
583 status
= bus_for_each_dev(&spi_bus_type
, NULL
, spi
, spi_dev_check
);
585 dev_err(dev
, "chipselect %d already in use\n",
590 /* Controller may unregister concurrently */
591 if (IS_ENABLED(CONFIG_SPI_DYNAMIC
) &&
592 !device_is_registered(&ctlr
->dev
)) {
597 /* Descriptors take precedence */
599 spi
->cs_gpiod
= ctlr
->cs_gpiods
[spi
->chip_select
];
600 else if (ctlr
->cs_gpios
)
601 spi
->cs_gpio
= ctlr
->cs_gpios
[spi
->chip_select
];
603 /* Drivers may modify this initial i/o setup, but will
604 * normally rely on the device being setup. Devices
605 * using SPI_CS_HIGH can't coexist well otherwise...
607 status
= spi_setup(spi
);
609 dev_err(dev
, "can't setup %s, status %d\n",
610 dev_name(&spi
->dev
), status
);
614 /* Device may be bound to an active driver when this returns */
615 status
= device_add(&spi
->dev
);
617 dev_err(dev
, "can't add %s, status %d\n",
618 dev_name(&spi
->dev
), status
);
620 dev_dbg(dev
, "registered child %s\n", dev_name(&spi
->dev
));
623 mutex_unlock(&spi_add_lock
);
626 EXPORT_SYMBOL_GPL(spi_add_device
);
629 * spi_new_device - instantiate one new SPI device
630 * @ctlr: Controller to which device is connected
631 * @chip: Describes the SPI device
634 * On typical mainboards, this is purely internal; and it's not needed
635 * after board init creates the hard-wired devices. Some development
636 * platforms may not be able to use spi_register_board_info though, and
637 * this is exported so that for example a USB or parport based adapter
638 * driver could add devices (which it would learn about out-of-band).
640 * Return: the new device, or NULL.
642 struct spi_device
*spi_new_device(struct spi_controller
*ctlr
,
643 struct spi_board_info
*chip
)
645 struct spi_device
*proxy
;
648 /* NOTE: caller did any chip->bus_num checks necessary.
650 * Also, unless we change the return value convention to use
651 * error-or-pointer (not NULL-or-pointer), troubleshootability
652 * suggests syslogged diagnostics are best here (ugh).
655 proxy
= spi_alloc_device(ctlr
);
659 WARN_ON(strlen(chip
->modalias
) >= sizeof(proxy
->modalias
));
661 proxy
->chip_select
= chip
->chip_select
;
662 proxy
->max_speed_hz
= chip
->max_speed_hz
;
663 proxy
->mode
= chip
->mode
;
664 proxy
->irq
= chip
->irq
;
665 strlcpy(proxy
->modalias
, chip
->modalias
, sizeof(proxy
->modalias
));
666 proxy
->dev
.platform_data
= (void *) chip
->platform_data
;
667 proxy
->controller_data
= chip
->controller_data
;
668 proxy
->controller_state
= NULL
;
670 if (chip
->properties
) {
671 status
= device_add_properties(&proxy
->dev
, chip
->properties
);
674 "failed to add properties to '%s': %d\n",
675 chip
->modalias
, status
);
680 status
= spi_add_device(proxy
);
682 goto err_remove_props
;
687 if (chip
->properties
)
688 device_remove_properties(&proxy
->dev
);
693 EXPORT_SYMBOL_GPL(spi_new_device
);
696 * spi_unregister_device - unregister a single SPI device
697 * @spi: spi_device to unregister
699 * Start making the passed SPI device vanish. Normally this would be handled
700 * by spi_unregister_controller().
702 void spi_unregister_device(struct spi_device
*spi
)
707 if (spi
->dev
.of_node
) {
708 of_node_clear_flag(spi
->dev
.of_node
, OF_POPULATED
);
709 of_node_put(spi
->dev
.of_node
);
711 if (ACPI_COMPANION(&spi
->dev
))
712 acpi_device_clear_enumerated(ACPI_COMPANION(&spi
->dev
));
713 device_unregister(&spi
->dev
);
715 EXPORT_SYMBOL_GPL(spi_unregister_device
);
717 static void spi_match_controller_to_boardinfo(struct spi_controller
*ctlr
,
718 struct spi_board_info
*bi
)
720 struct spi_device
*dev
;
722 if (ctlr
->bus_num
!= bi
->bus_num
)
725 dev
= spi_new_device(ctlr
, bi
);
727 dev_err(ctlr
->dev
.parent
, "can't create new device for %s\n",
732 * spi_register_board_info - register SPI devices for a given board
733 * @info: array of chip descriptors
734 * @n: how many descriptors are provided
737 * Board-specific early init code calls this (probably during arch_initcall)
738 * with segments of the SPI device table. Any device nodes are created later,
739 * after the relevant parent SPI controller (bus_num) is defined. We keep
740 * this table of devices forever, so that reloading a controller driver will
741 * not make Linux forget about these hard-wired devices.
743 * Other code can also call this, e.g. a particular add-on board might provide
744 * SPI devices through its expansion connector, so code initializing that board
745 * would naturally declare its SPI devices.
747 * The board info passed can safely be __initdata ... but be careful of
748 * any embedded pointers (platform_data, etc), they're copied as-is.
749 * Device properties are deep-copied though.
751 * Return: zero on success, else a negative error code.
753 int spi_register_board_info(struct spi_board_info
const *info
, unsigned n
)
755 struct boardinfo
*bi
;
761 bi
= kcalloc(n
, sizeof(*bi
), GFP_KERNEL
);
765 for (i
= 0; i
< n
; i
++, bi
++, info
++) {
766 struct spi_controller
*ctlr
;
768 memcpy(&bi
->board_info
, info
, sizeof(*info
));
769 if (info
->properties
) {
770 bi
->board_info
.properties
=
771 property_entries_dup(info
->properties
);
772 if (IS_ERR(bi
->board_info
.properties
))
773 return PTR_ERR(bi
->board_info
.properties
);
776 mutex_lock(&board_lock
);
777 list_add_tail(&bi
->list
, &board_list
);
778 list_for_each_entry(ctlr
, &spi_controller_list
, list
)
779 spi_match_controller_to_boardinfo(ctlr
,
781 mutex_unlock(&board_lock
);
787 /*-------------------------------------------------------------------------*/
789 static void spi_set_cs(struct spi_device
*spi
, bool enable
)
791 bool enable1
= enable
;
794 * Avoid calling into the driver (or doing delays) if the chip select
795 * isn't actually changing from the last time this was called.
797 if ((spi
->controller
->last_cs_enable
== enable
) &&
798 (spi
->controller
->last_cs_mode_high
== (spi
->mode
& SPI_CS_HIGH
)))
801 spi
->controller
->last_cs_enable
= enable
;
802 spi
->controller
->last_cs_mode_high
= spi
->mode
& SPI_CS_HIGH
;
804 if (!spi
->controller
->set_cs_timing
) {
806 spi_delay_exec(&spi
->controller
->cs_setup
, NULL
);
808 spi_delay_exec(&spi
->controller
->cs_hold
, NULL
);
811 if (spi
->mode
& SPI_CS_HIGH
)
814 if (spi
->cs_gpiod
|| gpio_is_valid(spi
->cs_gpio
)) {
815 if (!(spi
->mode
& SPI_NO_CS
)) {
817 /* polarity handled by gpiolib */
818 gpiod_set_value_cansleep(spi
->cs_gpiod
,
822 * invert the enable line, as active low is
825 gpio_set_value_cansleep(spi
->cs_gpio
, !enable
);
827 /* Some SPI masters need both GPIO CS & slave_select */
828 if ((spi
->controller
->flags
& SPI_MASTER_GPIO_SS
) &&
829 spi
->controller
->set_cs
)
830 spi
->controller
->set_cs(spi
, !enable
);
831 } else if (spi
->controller
->set_cs
) {
832 spi
->controller
->set_cs(spi
, !enable
);
835 if (!spi
->controller
->set_cs_timing
) {
837 spi_delay_exec(&spi
->controller
->cs_inactive
, NULL
);
841 #ifdef CONFIG_HAS_DMA
842 int spi_map_buf(struct spi_controller
*ctlr
, struct device
*dev
,
843 struct sg_table
*sgt
, void *buf
, size_t len
,
844 enum dma_data_direction dir
)
846 const bool vmalloced_buf
= is_vmalloc_addr(buf
);
847 unsigned int max_seg_size
= dma_get_max_seg_size(dev
);
848 #ifdef CONFIG_HIGHMEM
849 const bool kmap_buf
= ((unsigned long)buf
>= PKMAP_BASE
&&
850 (unsigned long)buf
< (PKMAP_BASE
+
851 (LAST_PKMAP
* PAGE_SIZE
)));
853 const bool kmap_buf
= false;
857 struct page
*vm_page
;
858 struct scatterlist
*sg
;
863 if (vmalloced_buf
|| kmap_buf
) {
864 desc_len
= min_t(int, max_seg_size
, PAGE_SIZE
);
865 sgs
= DIV_ROUND_UP(len
+ offset_in_page(buf
), desc_len
);
866 } else if (virt_addr_valid(buf
)) {
867 desc_len
= min_t(int, max_seg_size
, ctlr
->max_dma_len
);
868 sgs
= DIV_ROUND_UP(len
, desc_len
);
873 ret
= sg_alloc_table(sgt
, sgs
, GFP_KERNEL
);
878 for (i
= 0; i
< sgs
; i
++) {
880 if (vmalloced_buf
|| kmap_buf
) {
882 * Next scatterlist entry size is the minimum between
883 * the desc_len and the remaining buffer length that
886 min
= min_t(size_t, desc_len
,
888 PAGE_SIZE
- offset_in_page(buf
)));
890 vm_page
= vmalloc_to_page(buf
);
892 vm_page
= kmap_to_page(buf
);
897 sg_set_page(sg
, vm_page
,
898 min
, offset_in_page(buf
));
900 min
= min_t(size_t, len
, desc_len
);
902 sg_set_buf(sg
, sg_buf
, min
);
910 ret
= dma_map_sg(dev
, sgt
->sgl
, sgt
->nents
, dir
);
923 void spi_unmap_buf(struct spi_controller
*ctlr
, struct device
*dev
,
924 struct sg_table
*sgt
, enum dma_data_direction dir
)
926 if (sgt
->orig_nents
) {
927 dma_unmap_sg(dev
, sgt
->sgl
, sgt
->orig_nents
, dir
);
932 static int __spi_map_msg(struct spi_controller
*ctlr
, struct spi_message
*msg
)
934 struct device
*tx_dev
, *rx_dev
;
935 struct spi_transfer
*xfer
;
942 tx_dev
= ctlr
->dma_tx
->device
->dev
;
944 tx_dev
= ctlr
->dev
.parent
;
947 rx_dev
= ctlr
->dma_rx
->device
->dev
;
949 rx_dev
= ctlr
->dev
.parent
;
951 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
952 if (!ctlr
->can_dma(ctlr
, msg
->spi
, xfer
))
955 if (xfer
->tx_buf
!= NULL
) {
956 ret
= spi_map_buf(ctlr
, tx_dev
, &xfer
->tx_sg
,
957 (void *)xfer
->tx_buf
, xfer
->len
,
963 if (xfer
->rx_buf
!= NULL
) {
964 ret
= spi_map_buf(ctlr
, rx_dev
, &xfer
->rx_sg
,
965 xfer
->rx_buf
, xfer
->len
,
968 spi_unmap_buf(ctlr
, tx_dev
, &xfer
->tx_sg
,
975 ctlr
->cur_msg_mapped
= true;
980 static int __spi_unmap_msg(struct spi_controller
*ctlr
, struct spi_message
*msg
)
982 struct spi_transfer
*xfer
;
983 struct device
*tx_dev
, *rx_dev
;
985 if (!ctlr
->cur_msg_mapped
|| !ctlr
->can_dma
)
989 tx_dev
= ctlr
->dma_tx
->device
->dev
;
991 tx_dev
= ctlr
->dev
.parent
;
994 rx_dev
= ctlr
->dma_rx
->device
->dev
;
996 rx_dev
= ctlr
->dev
.parent
;
998 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
999 if (!ctlr
->can_dma(ctlr
, msg
->spi
, xfer
))
1002 spi_unmap_buf(ctlr
, rx_dev
, &xfer
->rx_sg
, DMA_FROM_DEVICE
);
1003 spi_unmap_buf(ctlr
, tx_dev
, &xfer
->tx_sg
, DMA_TO_DEVICE
);
1006 ctlr
->cur_msg_mapped
= false;
1010 #else /* !CONFIG_HAS_DMA */
1011 static inline int __spi_map_msg(struct spi_controller
*ctlr
,
1012 struct spi_message
*msg
)
1017 static inline int __spi_unmap_msg(struct spi_controller
*ctlr
,
1018 struct spi_message
*msg
)
1022 #endif /* !CONFIG_HAS_DMA */
1024 static inline int spi_unmap_msg(struct spi_controller
*ctlr
,
1025 struct spi_message
*msg
)
1027 struct spi_transfer
*xfer
;
1029 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
1031 * Restore the original value of tx_buf or rx_buf if they are
1034 if (xfer
->tx_buf
== ctlr
->dummy_tx
)
1035 xfer
->tx_buf
= NULL
;
1036 if (xfer
->rx_buf
== ctlr
->dummy_rx
)
1037 xfer
->rx_buf
= NULL
;
1040 return __spi_unmap_msg(ctlr
, msg
);
1043 static int spi_map_msg(struct spi_controller
*ctlr
, struct spi_message
*msg
)
1045 struct spi_transfer
*xfer
;
1047 unsigned int max_tx
, max_rx
;
1049 if ((ctlr
->flags
& (SPI_CONTROLLER_MUST_RX
| SPI_CONTROLLER_MUST_TX
))
1050 && !(msg
->spi
->mode
& SPI_3WIRE
)) {
1054 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
1055 if ((ctlr
->flags
& SPI_CONTROLLER_MUST_TX
) &&
1057 max_tx
= max(xfer
->len
, max_tx
);
1058 if ((ctlr
->flags
& SPI_CONTROLLER_MUST_RX
) &&
1060 max_rx
= max(xfer
->len
, max_rx
);
1064 tmp
= krealloc(ctlr
->dummy_tx
, max_tx
,
1065 GFP_KERNEL
| GFP_DMA
);
1068 ctlr
->dummy_tx
= tmp
;
1069 memset(tmp
, 0, max_tx
);
1073 tmp
= krealloc(ctlr
->dummy_rx
, max_rx
,
1074 GFP_KERNEL
| GFP_DMA
);
1077 ctlr
->dummy_rx
= tmp
;
1080 if (max_tx
|| max_rx
) {
1081 list_for_each_entry(xfer
, &msg
->transfers
,
1086 xfer
->tx_buf
= ctlr
->dummy_tx
;
1088 xfer
->rx_buf
= ctlr
->dummy_rx
;
1093 return __spi_map_msg(ctlr
, msg
);
1096 static int spi_transfer_wait(struct spi_controller
*ctlr
,
1097 struct spi_message
*msg
,
1098 struct spi_transfer
*xfer
)
1100 struct spi_statistics
*statm
= &ctlr
->statistics
;
1101 struct spi_statistics
*stats
= &msg
->spi
->statistics
;
1102 unsigned long long ms
;
1104 if (spi_controller_is_slave(ctlr
)) {
1105 if (wait_for_completion_interruptible(&ctlr
->xfer_completion
)) {
1106 dev_dbg(&msg
->spi
->dev
, "SPI transfer interrupted\n");
1110 ms
= 8LL * 1000LL * xfer
->len
;
1111 do_div(ms
, xfer
->speed_hz
);
1112 ms
+= ms
+ 200; /* some tolerance */
1117 ms
= wait_for_completion_timeout(&ctlr
->xfer_completion
,
1118 msecs_to_jiffies(ms
));
1121 SPI_STATISTICS_INCREMENT_FIELD(statm
, timedout
);
1122 SPI_STATISTICS_INCREMENT_FIELD(stats
, timedout
);
1123 dev_err(&msg
->spi
->dev
,
1124 "SPI transfer timed out\n");
1132 static void _spi_transfer_delay_ns(u32 ns
)
1139 u32 us
= DIV_ROUND_UP(ns
, 1000);
1144 usleep_range(us
, us
+ DIV_ROUND_UP(us
, 10));
1148 int spi_delay_to_ns(struct spi_delay
*_delay
, struct spi_transfer
*xfer
)
1150 u32 delay
= _delay
->value
;
1151 u32 unit
= _delay
->unit
;
1158 case SPI_DELAY_UNIT_USECS
:
1161 case SPI_DELAY_UNIT_NSECS
: /* nothing to do here */
1163 case SPI_DELAY_UNIT_SCK
:
1164 /* clock cycles need to be obtained from spi_transfer */
1167 /* if there is no effective speed know, then approximate
1168 * by underestimating with half the requested hz
1170 hz
= xfer
->effective_speed_hz
?: xfer
->speed_hz
/ 2;
1173 delay
*= DIV_ROUND_UP(1000000000, hz
);
1181 EXPORT_SYMBOL_GPL(spi_delay_to_ns
);
1183 int spi_delay_exec(struct spi_delay
*_delay
, struct spi_transfer
*xfer
)
1192 delay
= spi_delay_to_ns(_delay
, xfer
);
1196 _spi_transfer_delay_ns(delay
);
1200 EXPORT_SYMBOL_GPL(spi_delay_exec
);
1202 static void _spi_transfer_cs_change_delay(struct spi_message
*msg
,
1203 struct spi_transfer
*xfer
)
1205 u32 delay
= xfer
->cs_change_delay
.value
;
1206 u32 unit
= xfer
->cs_change_delay
.unit
;
1209 /* return early on "fast" mode - for everything but USECS */
1211 if (unit
== SPI_DELAY_UNIT_USECS
)
1212 _spi_transfer_delay_ns(10000);
1216 ret
= spi_delay_exec(&xfer
->cs_change_delay
, xfer
);
1218 dev_err_once(&msg
->spi
->dev
,
1219 "Use of unsupported delay unit %i, using default of 10us\n",
1221 _spi_transfer_delay_ns(10000);
1226 * spi_transfer_one_message - Default implementation of transfer_one_message()
1228 * This is a standard implementation of transfer_one_message() for
1229 * drivers which implement a transfer_one() operation. It provides
1230 * standard handling of delays and chip select management.
1232 static int spi_transfer_one_message(struct spi_controller
*ctlr
,
1233 struct spi_message
*msg
)
1235 struct spi_transfer
*xfer
;
1236 bool keep_cs
= false;
1238 struct spi_statistics
*statm
= &ctlr
->statistics
;
1239 struct spi_statistics
*stats
= &msg
->spi
->statistics
;
1241 spi_set_cs(msg
->spi
, true);
1243 SPI_STATISTICS_INCREMENT_FIELD(statm
, messages
);
1244 SPI_STATISTICS_INCREMENT_FIELD(stats
, messages
);
1246 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
1247 trace_spi_transfer_start(msg
, xfer
);
1249 spi_statistics_add_transfer_stats(statm
, xfer
, ctlr
);
1250 spi_statistics_add_transfer_stats(stats
, xfer
, ctlr
);
1252 if (!ctlr
->ptp_sts_supported
) {
1253 xfer
->ptp_sts_word_pre
= 0;
1254 ptp_read_system_prets(xfer
->ptp_sts
);
1257 if (xfer
->tx_buf
|| xfer
->rx_buf
) {
1258 reinit_completion(&ctlr
->xfer_completion
);
1261 ret
= ctlr
->transfer_one(ctlr
, msg
->spi
, xfer
);
1263 if (ctlr
->cur_msg_mapped
&&
1264 (xfer
->error
& SPI_TRANS_FAIL_NO_START
)) {
1265 __spi_unmap_msg(ctlr
, msg
);
1266 ctlr
->fallback
= true;
1267 xfer
->error
&= ~SPI_TRANS_FAIL_NO_START
;
1271 SPI_STATISTICS_INCREMENT_FIELD(statm
,
1273 SPI_STATISTICS_INCREMENT_FIELD(stats
,
1275 dev_err(&msg
->spi
->dev
,
1276 "SPI transfer failed: %d\n", ret
);
1281 ret
= spi_transfer_wait(ctlr
, msg
, xfer
);
1287 dev_err(&msg
->spi
->dev
,
1288 "Bufferless transfer has length %u\n",
1292 if (!ctlr
->ptp_sts_supported
) {
1293 ptp_read_system_postts(xfer
->ptp_sts
);
1294 xfer
->ptp_sts_word_post
= xfer
->len
;
1297 trace_spi_transfer_stop(msg
, xfer
);
1299 if (msg
->status
!= -EINPROGRESS
)
1302 spi_transfer_delay_exec(xfer
);
1304 if (xfer
->cs_change
) {
1305 if (list_is_last(&xfer
->transfer_list
,
1309 spi_set_cs(msg
->spi
, false);
1310 _spi_transfer_cs_change_delay(msg
, xfer
);
1311 spi_set_cs(msg
->spi
, true);
1315 msg
->actual_length
+= xfer
->len
;
1319 if (ret
!= 0 || !keep_cs
)
1320 spi_set_cs(msg
->spi
, false);
1322 if (msg
->status
== -EINPROGRESS
)
1325 if (msg
->status
&& ctlr
->handle_err
)
1326 ctlr
->handle_err(ctlr
, msg
);
1328 spi_finalize_current_message(ctlr
);
1334 * spi_finalize_current_transfer - report completion of a transfer
1335 * @ctlr: the controller reporting completion
1337 * Called by SPI drivers using the core transfer_one_message()
1338 * implementation to notify it that the current interrupt driven
1339 * transfer has finished and the next one may be scheduled.
1341 void spi_finalize_current_transfer(struct spi_controller
*ctlr
)
1343 complete(&ctlr
->xfer_completion
);
1345 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer
);
1347 static void spi_idle_runtime_pm(struct spi_controller
*ctlr
)
1349 if (ctlr
->auto_runtime_pm
) {
1350 pm_runtime_mark_last_busy(ctlr
->dev
.parent
);
1351 pm_runtime_put_autosuspend(ctlr
->dev
.parent
);
1356 * __spi_pump_messages - function which processes spi message queue
1357 * @ctlr: controller to process queue for
1358 * @in_kthread: true if we are in the context of the message pump thread
1360 * This function checks if there is any spi message in the queue that
1361 * needs processing and if so call out to the driver to initialize hardware
1362 * and transfer each message.
1364 * Note that it is called both from the kthread itself and also from
1365 * inside spi_sync(); the queue extraction handling at the top of the
1366 * function should deal with this safely.
1368 static void __spi_pump_messages(struct spi_controller
*ctlr
, bool in_kthread
)
1370 struct spi_transfer
*xfer
;
1371 struct spi_message
*msg
;
1372 bool was_busy
= false;
1373 unsigned long flags
;
1377 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1379 /* Make sure we are not already running a message */
1380 if (ctlr
->cur_msg
) {
1381 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1385 /* If another context is idling the device then defer */
1387 kthread_queue_work(ctlr
->kworker
, &ctlr
->pump_messages
);
1388 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1392 /* Check if the queue is idle */
1393 if (list_empty(&ctlr
->queue
) || !ctlr
->running
) {
1395 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1399 /* Defer any non-atomic teardown to the thread */
1401 if (!ctlr
->dummy_rx
&& !ctlr
->dummy_tx
&&
1402 !ctlr
->unprepare_transfer_hardware
) {
1403 spi_idle_runtime_pm(ctlr
);
1405 trace_spi_controller_idle(ctlr
);
1407 kthread_queue_work(ctlr
->kworker
,
1408 &ctlr
->pump_messages
);
1410 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1415 ctlr
->idling
= true;
1416 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1418 kfree(ctlr
->dummy_rx
);
1419 ctlr
->dummy_rx
= NULL
;
1420 kfree(ctlr
->dummy_tx
);
1421 ctlr
->dummy_tx
= NULL
;
1422 if (ctlr
->unprepare_transfer_hardware
&&
1423 ctlr
->unprepare_transfer_hardware(ctlr
))
1425 "failed to unprepare transfer hardware\n");
1426 spi_idle_runtime_pm(ctlr
);
1427 trace_spi_controller_idle(ctlr
);
1429 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1430 ctlr
->idling
= false;
1431 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1435 /* Extract head of queue */
1436 msg
= list_first_entry(&ctlr
->queue
, struct spi_message
, queue
);
1437 ctlr
->cur_msg
= msg
;
1439 list_del_init(&msg
->queue
);
1444 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1446 mutex_lock(&ctlr
->io_mutex
);
1448 if (!was_busy
&& ctlr
->auto_runtime_pm
) {
1449 ret
= pm_runtime_get_sync(ctlr
->dev
.parent
);
1451 pm_runtime_put_noidle(ctlr
->dev
.parent
);
1452 dev_err(&ctlr
->dev
, "Failed to power device: %d\n",
1454 mutex_unlock(&ctlr
->io_mutex
);
1460 trace_spi_controller_busy(ctlr
);
1462 if (!was_busy
&& ctlr
->prepare_transfer_hardware
) {
1463 ret
= ctlr
->prepare_transfer_hardware(ctlr
);
1466 "failed to prepare transfer hardware: %d\n",
1469 if (ctlr
->auto_runtime_pm
)
1470 pm_runtime_put(ctlr
->dev
.parent
);
1473 spi_finalize_current_message(ctlr
);
1475 mutex_unlock(&ctlr
->io_mutex
);
1480 trace_spi_message_start(msg
);
1482 if (ctlr
->prepare_message
) {
1483 ret
= ctlr
->prepare_message(ctlr
, msg
);
1485 dev_err(&ctlr
->dev
, "failed to prepare message: %d\n",
1488 spi_finalize_current_message(ctlr
);
1491 ctlr
->cur_msg_prepared
= true;
1494 ret
= spi_map_msg(ctlr
, msg
);
1497 spi_finalize_current_message(ctlr
);
1501 if (!ctlr
->ptp_sts_supported
&& !ctlr
->transfer_one
) {
1502 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
1503 xfer
->ptp_sts_word_pre
= 0;
1504 ptp_read_system_prets(xfer
->ptp_sts
);
1508 ret
= ctlr
->transfer_one_message(ctlr
, msg
);
1511 "failed to transfer one message from queue\n");
1516 mutex_unlock(&ctlr
->io_mutex
);
1518 /* Prod the scheduler in case transfer_one() was busy waiting */
1524 * spi_pump_messages - kthread work function which processes spi message queue
1525 * @work: pointer to kthread work struct contained in the controller struct
1527 static void spi_pump_messages(struct kthread_work
*work
)
1529 struct spi_controller
*ctlr
=
1530 container_of(work
, struct spi_controller
, pump_messages
);
1532 __spi_pump_messages(ctlr
, true);
1536 * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
1537 * TX timestamp for the requested byte from the SPI
1538 * transfer. The frequency with which this function
1539 * must be called (once per word, once for the whole
1540 * transfer, once per batch of words etc) is arbitrary
1541 * as long as the @tx buffer offset is greater than or
1542 * equal to the requested byte at the time of the
1543 * call. The timestamp is only taken once, at the
1544 * first such call. It is assumed that the driver
1545 * advances its @tx buffer pointer monotonically.
1546 * @ctlr: Pointer to the spi_controller structure of the driver
1547 * @xfer: Pointer to the transfer being timestamped
1548 * @progress: How many words (not bytes) have been transferred so far
1549 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1550 * transfer, for less jitter in time measurement. Only compatible
1551 * with PIO drivers. If true, must follow up with
1552 * spi_take_timestamp_post or otherwise system will crash.
1553 * WARNING: for fully predictable results, the CPU frequency must
1554 * also be under control (governor).
1556 void spi_take_timestamp_pre(struct spi_controller
*ctlr
,
1557 struct spi_transfer
*xfer
,
1558 size_t progress
, bool irqs_off
)
1563 if (xfer
->timestamped
)
1566 if (progress
> xfer
->ptp_sts_word_pre
)
1569 /* Capture the resolution of the timestamp */
1570 xfer
->ptp_sts_word_pre
= progress
;
1573 local_irq_save(ctlr
->irq_flags
);
1577 ptp_read_system_prets(xfer
->ptp_sts
);
1579 EXPORT_SYMBOL_GPL(spi_take_timestamp_pre
);
1582 * spi_take_timestamp_post - helper for drivers to collect the end of the
1583 * TX timestamp for the requested byte from the SPI
1584 * transfer. Can be called with an arbitrary
1585 * frequency: only the first call where @tx exceeds
1586 * or is equal to the requested word will be
1588 * @ctlr: Pointer to the spi_controller structure of the driver
1589 * @xfer: Pointer to the transfer being timestamped
1590 * @progress: How many words (not bytes) have been transferred so far
1591 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1593 void spi_take_timestamp_post(struct spi_controller
*ctlr
,
1594 struct spi_transfer
*xfer
,
1595 size_t progress
, bool irqs_off
)
1600 if (xfer
->timestamped
)
1603 if (progress
< xfer
->ptp_sts_word_post
)
1606 ptp_read_system_postts(xfer
->ptp_sts
);
1609 local_irq_restore(ctlr
->irq_flags
);
1613 /* Capture the resolution of the timestamp */
1614 xfer
->ptp_sts_word_post
= progress
;
1616 xfer
->timestamped
= true;
1618 EXPORT_SYMBOL_GPL(spi_take_timestamp_post
);
1621 * spi_set_thread_rt - set the controller to pump at realtime priority
1622 * @ctlr: controller to boost priority of
1624 * This can be called because the controller requested realtime priority
1625 * (by setting the ->rt value before calling spi_register_controller()) or
1626 * because a device on the bus said that its transfers needed realtime
1629 * NOTE: at the moment if any device on a bus says it needs realtime then
1630 * the thread will be at realtime priority for all transfers on that
1631 * controller. If this eventually becomes a problem we may see if we can
1632 * find a way to boost the priority only temporarily during relevant
1635 static void spi_set_thread_rt(struct spi_controller
*ctlr
)
1637 dev_info(&ctlr
->dev
,
1638 "will run message pump with realtime priority\n");
1639 sched_set_fifo(ctlr
->kworker
->task
);
1642 static int spi_init_queue(struct spi_controller
*ctlr
)
1644 ctlr
->running
= false;
1647 ctlr
->kworker
= kthread_create_worker(0, dev_name(&ctlr
->dev
));
1648 if (IS_ERR(ctlr
->kworker
)) {
1649 dev_err(&ctlr
->dev
, "failed to create message pump kworker\n");
1650 return PTR_ERR(ctlr
->kworker
);
1653 kthread_init_work(&ctlr
->pump_messages
, spi_pump_messages
);
1656 * Controller config will indicate if this controller should run the
1657 * message pump with high (realtime) priority to reduce the transfer
1658 * latency on the bus by minimising the delay between a transfer
1659 * request and the scheduling of the message pump thread. Without this
1660 * setting the message pump thread will remain at default priority.
1663 spi_set_thread_rt(ctlr
);
1669 * spi_get_next_queued_message() - called by driver to check for queued
1671 * @ctlr: the controller to check for queued messages
1673 * If there are more messages in the queue, the next message is returned from
1676 * Return: the next message in the queue, else NULL if the queue is empty.
1678 struct spi_message
*spi_get_next_queued_message(struct spi_controller
*ctlr
)
1680 struct spi_message
*next
;
1681 unsigned long flags
;
1683 /* get a pointer to the next message, if any */
1684 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1685 next
= list_first_entry_or_null(&ctlr
->queue
, struct spi_message
,
1687 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1691 EXPORT_SYMBOL_GPL(spi_get_next_queued_message
);
1694 * spi_finalize_current_message() - the current message is complete
1695 * @ctlr: the controller to return the message to
1697 * Called by the driver to notify the core that the message in the front of the
1698 * queue is complete and can be removed from the queue.
1700 void spi_finalize_current_message(struct spi_controller
*ctlr
)
1702 struct spi_transfer
*xfer
;
1703 struct spi_message
*mesg
;
1704 unsigned long flags
;
1707 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1708 mesg
= ctlr
->cur_msg
;
1709 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1711 if (!ctlr
->ptp_sts_supported
&& !ctlr
->transfer_one
) {
1712 list_for_each_entry(xfer
, &mesg
->transfers
, transfer_list
) {
1713 ptp_read_system_postts(xfer
->ptp_sts
);
1714 xfer
->ptp_sts_word_post
= xfer
->len
;
1718 if (unlikely(ctlr
->ptp_sts_supported
))
1719 list_for_each_entry(xfer
, &mesg
->transfers
, transfer_list
)
1720 WARN_ON_ONCE(xfer
->ptp_sts
&& !xfer
->timestamped
);
1722 spi_unmap_msg(ctlr
, mesg
);
1724 /* In the prepare_messages callback the spi bus has the opportunity to
1725 * split a transfer to smaller chunks.
1726 * Release splited transfers here since spi_map_msg is done on the
1727 * splited transfers.
1729 spi_res_release(ctlr
, mesg
);
1731 if (ctlr
->cur_msg_prepared
&& ctlr
->unprepare_message
) {
1732 ret
= ctlr
->unprepare_message(ctlr
, mesg
);
1734 dev_err(&ctlr
->dev
, "failed to unprepare message: %d\n",
1739 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1740 ctlr
->cur_msg
= NULL
;
1741 ctlr
->cur_msg_prepared
= false;
1742 ctlr
->fallback
= false;
1743 kthread_queue_work(ctlr
->kworker
, &ctlr
->pump_messages
);
1744 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1746 trace_spi_message_done(mesg
);
1750 mesg
->complete(mesg
->context
);
1752 EXPORT_SYMBOL_GPL(spi_finalize_current_message
);
1754 static int spi_start_queue(struct spi_controller
*ctlr
)
1756 unsigned long flags
;
1758 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1760 if (ctlr
->running
|| ctlr
->busy
) {
1761 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1765 ctlr
->running
= true;
1766 ctlr
->cur_msg
= NULL
;
1767 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1769 kthread_queue_work(ctlr
->kworker
, &ctlr
->pump_messages
);
1774 static int spi_stop_queue(struct spi_controller
*ctlr
)
1776 unsigned long flags
;
1777 unsigned limit
= 500;
1780 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1783 * This is a bit lame, but is optimized for the common execution path.
1784 * A wait_queue on the ctlr->busy could be used, but then the common
1785 * execution path (pump_messages) would be required to call wake_up or
1786 * friends on every SPI message. Do this instead.
1788 while ((!list_empty(&ctlr
->queue
) || ctlr
->busy
) && limit
--) {
1789 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1790 usleep_range(10000, 11000);
1791 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1794 if (!list_empty(&ctlr
->queue
) || ctlr
->busy
)
1797 ctlr
->running
= false;
1799 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1802 dev_warn(&ctlr
->dev
, "could not stop message queue\n");
1808 static int spi_destroy_queue(struct spi_controller
*ctlr
)
1812 ret
= spi_stop_queue(ctlr
);
1815 * kthread_flush_worker will block until all work is done.
1816 * If the reason that stop_queue timed out is that the work will never
1817 * finish, then it does no good to call flush/stop thread, so
1821 dev_err(&ctlr
->dev
, "problem destroying queue\n");
1825 kthread_destroy_worker(ctlr
->kworker
);
1830 static int __spi_queued_transfer(struct spi_device
*spi
,
1831 struct spi_message
*msg
,
1834 struct spi_controller
*ctlr
= spi
->controller
;
1835 unsigned long flags
;
1837 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1839 if (!ctlr
->running
) {
1840 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1843 msg
->actual_length
= 0;
1844 msg
->status
= -EINPROGRESS
;
1846 list_add_tail(&msg
->queue
, &ctlr
->queue
);
1847 if (!ctlr
->busy
&& need_pump
)
1848 kthread_queue_work(ctlr
->kworker
, &ctlr
->pump_messages
);
1850 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1855 * spi_queued_transfer - transfer function for queued transfers
1856 * @spi: spi device which is requesting transfer
1857 * @msg: spi message which is to handled is queued to driver queue
1859 * Return: zero on success, else a negative error code.
1861 static int spi_queued_transfer(struct spi_device
*spi
, struct spi_message
*msg
)
1863 return __spi_queued_transfer(spi
, msg
, true);
1866 static int spi_controller_initialize_queue(struct spi_controller
*ctlr
)
1870 ctlr
->transfer
= spi_queued_transfer
;
1871 if (!ctlr
->transfer_one_message
)
1872 ctlr
->transfer_one_message
= spi_transfer_one_message
;
1874 /* Initialize and start queue */
1875 ret
= spi_init_queue(ctlr
);
1877 dev_err(&ctlr
->dev
, "problem initializing queue\n");
1878 goto err_init_queue
;
1880 ctlr
->queued
= true;
1881 ret
= spi_start_queue(ctlr
);
1883 dev_err(&ctlr
->dev
, "problem starting queue\n");
1884 goto err_start_queue
;
1890 spi_destroy_queue(ctlr
);
1896 * spi_flush_queue - Send all pending messages in the queue from the callers'
1898 * @ctlr: controller to process queue for
1900 * This should be used when one wants to ensure all pending messages have been
1901 * sent before doing something. Is used by the spi-mem code to make sure SPI
1902 * memory operations do not preempt regular SPI transfers that have been queued
1903 * before the spi-mem operation.
1905 void spi_flush_queue(struct spi_controller
*ctlr
)
1907 if (ctlr
->transfer
== spi_queued_transfer
)
1908 __spi_pump_messages(ctlr
, false);
1911 /*-------------------------------------------------------------------------*/
1913 #if defined(CONFIG_OF)
1914 static int of_spi_parse_dt(struct spi_controller
*ctlr
, struct spi_device
*spi
,
1915 struct device_node
*nc
)
1920 /* Mode (clock phase/polarity/etc.) */
1921 if (of_property_read_bool(nc
, "spi-cpha"))
1922 spi
->mode
|= SPI_CPHA
;
1923 if (of_property_read_bool(nc
, "spi-cpol"))
1924 spi
->mode
|= SPI_CPOL
;
1925 if (of_property_read_bool(nc
, "spi-3wire"))
1926 spi
->mode
|= SPI_3WIRE
;
1927 if (of_property_read_bool(nc
, "spi-lsb-first"))
1928 spi
->mode
|= SPI_LSB_FIRST
;
1929 if (of_property_read_bool(nc
, "spi-cs-high"))
1930 spi
->mode
|= SPI_CS_HIGH
;
1932 /* Device DUAL/QUAD mode */
1933 if (!of_property_read_u32(nc
, "spi-tx-bus-width", &value
)) {
1938 spi
->mode
|= SPI_TX_DUAL
;
1941 spi
->mode
|= SPI_TX_QUAD
;
1944 spi
->mode
|= SPI_TX_OCTAL
;
1947 dev_warn(&ctlr
->dev
,
1948 "spi-tx-bus-width %d not supported\n",
1954 if (!of_property_read_u32(nc
, "spi-rx-bus-width", &value
)) {
1959 spi
->mode
|= SPI_RX_DUAL
;
1962 spi
->mode
|= SPI_RX_QUAD
;
1965 spi
->mode
|= SPI_RX_OCTAL
;
1968 dev_warn(&ctlr
->dev
,
1969 "spi-rx-bus-width %d not supported\n",
1975 if (spi_controller_is_slave(ctlr
)) {
1976 if (!of_node_name_eq(nc
, "slave")) {
1977 dev_err(&ctlr
->dev
, "%pOF is not called 'slave'\n",
1984 /* Device address */
1985 rc
= of_property_read_u32(nc
, "reg", &value
);
1987 dev_err(&ctlr
->dev
, "%pOF has no valid 'reg' property (%d)\n",
1991 spi
->chip_select
= value
;
1994 if (!of_property_read_u32(nc
, "spi-max-frequency", &value
))
1995 spi
->max_speed_hz
= value
;
2000 static struct spi_device
*
2001 of_register_spi_device(struct spi_controller
*ctlr
, struct device_node
*nc
)
2003 struct spi_device
*spi
;
2006 /* Alloc an spi_device */
2007 spi
= spi_alloc_device(ctlr
);
2009 dev_err(&ctlr
->dev
, "spi_device alloc error for %pOF\n", nc
);
2014 /* Select device driver */
2015 rc
= of_modalias_node(nc
, spi
->modalias
,
2016 sizeof(spi
->modalias
));
2018 dev_err(&ctlr
->dev
, "cannot find modalias for %pOF\n", nc
);
2022 rc
= of_spi_parse_dt(ctlr
, spi
, nc
);
2026 /* Store a pointer to the node in the device structure */
2028 spi
->dev
.of_node
= nc
;
2030 /* Register the new device */
2031 rc
= spi_add_device(spi
);
2033 dev_err(&ctlr
->dev
, "spi_device register error %pOF\n", nc
);
2034 goto err_of_node_put
;
2047 * of_register_spi_devices() - Register child devices onto the SPI bus
2048 * @ctlr: Pointer to spi_controller device
2050 * Registers an spi_device for each child node of controller node which
2051 * represents a valid SPI slave.
2053 static void of_register_spi_devices(struct spi_controller
*ctlr
)
2055 struct spi_device
*spi
;
2056 struct device_node
*nc
;
2058 if (!ctlr
->dev
.of_node
)
2061 for_each_available_child_of_node(ctlr
->dev
.of_node
, nc
) {
2062 if (of_node_test_and_set_flag(nc
, OF_POPULATED
))
2064 spi
= of_register_spi_device(ctlr
, nc
);
2066 dev_warn(&ctlr
->dev
,
2067 "Failed to create SPI device for %pOF\n", nc
);
2068 of_node_clear_flag(nc
, OF_POPULATED
);
2073 static void of_register_spi_devices(struct spi_controller
*ctlr
) { }
2077 struct acpi_spi_lookup
{
2078 struct spi_controller
*ctlr
;
2086 static void acpi_spi_parse_apple_properties(struct acpi_device
*dev
,
2087 struct acpi_spi_lookup
*lookup
)
2089 const union acpi_object
*obj
;
2091 if (!x86_apple_machine
)
2094 if (!acpi_dev_get_property(dev
, "spiSclkPeriod", ACPI_TYPE_BUFFER
, &obj
)
2095 && obj
->buffer
.length
>= 4)
2096 lookup
->max_speed_hz
= NSEC_PER_SEC
/ *(u32
*)obj
->buffer
.pointer
;
2098 if (!acpi_dev_get_property(dev
, "spiWordSize", ACPI_TYPE_BUFFER
, &obj
)
2099 && obj
->buffer
.length
== 8)
2100 lookup
->bits_per_word
= *(u64
*)obj
->buffer
.pointer
;
2102 if (!acpi_dev_get_property(dev
, "spiBitOrder", ACPI_TYPE_BUFFER
, &obj
)
2103 && obj
->buffer
.length
== 8 && !*(u64
*)obj
->buffer
.pointer
)
2104 lookup
->mode
|= SPI_LSB_FIRST
;
2106 if (!acpi_dev_get_property(dev
, "spiSPO", ACPI_TYPE_BUFFER
, &obj
)
2107 && obj
->buffer
.length
== 8 && *(u64
*)obj
->buffer
.pointer
)
2108 lookup
->mode
|= SPI_CPOL
;
2110 if (!acpi_dev_get_property(dev
, "spiSPH", ACPI_TYPE_BUFFER
, &obj
)
2111 && obj
->buffer
.length
== 8 && *(u64
*)obj
->buffer
.pointer
)
2112 lookup
->mode
|= SPI_CPHA
;
2115 static int acpi_spi_add_resource(struct acpi_resource
*ares
, void *data
)
2117 struct acpi_spi_lookup
*lookup
= data
;
2118 struct spi_controller
*ctlr
= lookup
->ctlr
;
2120 if (ares
->type
== ACPI_RESOURCE_TYPE_SERIAL_BUS
) {
2121 struct acpi_resource_spi_serialbus
*sb
;
2122 acpi_handle parent_handle
;
2125 sb
= &ares
->data
.spi_serial_bus
;
2126 if (sb
->type
== ACPI_RESOURCE_SERIAL_TYPE_SPI
) {
2128 status
= acpi_get_handle(NULL
,
2129 sb
->resource_source
.string_ptr
,
2132 if (ACPI_FAILURE(status
) ||
2133 ACPI_HANDLE(ctlr
->dev
.parent
) != parent_handle
)
2137 * ACPI DeviceSelection numbering is handled by the
2138 * host controller driver in Windows and can vary
2139 * from driver to driver. In Linux we always expect
2140 * 0 .. max - 1 so we need to ask the driver to
2141 * translate between the two schemes.
2143 if (ctlr
->fw_translate_cs
) {
2144 int cs
= ctlr
->fw_translate_cs(ctlr
,
2145 sb
->device_selection
);
2148 lookup
->chip_select
= cs
;
2150 lookup
->chip_select
= sb
->device_selection
;
2153 lookup
->max_speed_hz
= sb
->connection_speed
;
2154 lookup
->bits_per_word
= sb
->data_bit_length
;
2156 if (sb
->clock_phase
== ACPI_SPI_SECOND_PHASE
)
2157 lookup
->mode
|= SPI_CPHA
;
2158 if (sb
->clock_polarity
== ACPI_SPI_START_HIGH
)
2159 lookup
->mode
|= SPI_CPOL
;
2160 if (sb
->device_polarity
== ACPI_SPI_ACTIVE_HIGH
)
2161 lookup
->mode
|= SPI_CS_HIGH
;
2163 } else if (lookup
->irq
< 0) {
2166 if (acpi_dev_resource_interrupt(ares
, 0, &r
))
2167 lookup
->irq
= r
.start
;
2170 /* Always tell the ACPI core to skip this resource */
2174 static acpi_status
acpi_register_spi_device(struct spi_controller
*ctlr
,
2175 struct acpi_device
*adev
)
2177 acpi_handle parent_handle
= NULL
;
2178 struct list_head resource_list
;
2179 struct acpi_spi_lookup lookup
= {};
2180 struct spi_device
*spi
;
2183 if (acpi_bus_get_status(adev
) || !adev
->status
.present
||
2184 acpi_device_enumerated(adev
))
2190 INIT_LIST_HEAD(&resource_list
);
2191 ret
= acpi_dev_get_resources(adev
, &resource_list
,
2192 acpi_spi_add_resource
, &lookup
);
2193 acpi_dev_free_resource_list(&resource_list
);
2196 /* found SPI in _CRS but it points to another controller */
2199 if (!lookup
.max_speed_hz
&&
2200 !ACPI_FAILURE(acpi_get_parent(adev
->handle
, &parent_handle
)) &&
2201 ACPI_HANDLE(ctlr
->dev
.parent
) == parent_handle
) {
2202 /* Apple does not use _CRS but nested devices for SPI slaves */
2203 acpi_spi_parse_apple_properties(adev
, &lookup
);
2206 if (!lookup
.max_speed_hz
)
2209 spi
= spi_alloc_device(ctlr
);
2211 dev_err(&ctlr
->dev
, "failed to allocate SPI device for %s\n",
2212 dev_name(&adev
->dev
));
2213 return AE_NO_MEMORY
;
2217 ACPI_COMPANION_SET(&spi
->dev
, adev
);
2218 spi
->max_speed_hz
= lookup
.max_speed_hz
;
2219 spi
->mode
|= lookup
.mode
;
2220 spi
->irq
= lookup
.irq
;
2221 spi
->bits_per_word
= lookup
.bits_per_word
;
2222 spi
->chip_select
= lookup
.chip_select
;
2224 acpi_set_modalias(adev
, acpi_device_hid(adev
), spi
->modalias
,
2225 sizeof(spi
->modalias
));
2228 spi
->irq
= acpi_dev_gpio_irq_get(adev
, 0);
2230 acpi_device_set_enumerated(adev
);
2232 adev
->power
.flags
.ignore_parent
= true;
2233 if (spi_add_device(spi
)) {
2234 adev
->power
.flags
.ignore_parent
= false;
2235 dev_err(&ctlr
->dev
, "failed to add SPI device %s from ACPI\n",
2236 dev_name(&adev
->dev
));
2243 static acpi_status
acpi_spi_add_device(acpi_handle handle
, u32 level
,
2244 void *data
, void **return_value
)
2246 struct spi_controller
*ctlr
= data
;
2247 struct acpi_device
*adev
;
2249 if (acpi_bus_get_device(handle
, &adev
))
2252 return acpi_register_spi_device(ctlr
, adev
);
2255 #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2257 static void acpi_register_spi_devices(struct spi_controller
*ctlr
)
2262 handle
= ACPI_HANDLE(ctlr
->dev
.parent
);
2266 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
2267 SPI_ACPI_ENUMERATE_MAX_DEPTH
,
2268 acpi_spi_add_device
, NULL
, ctlr
, NULL
);
2269 if (ACPI_FAILURE(status
))
2270 dev_warn(&ctlr
->dev
, "failed to enumerate SPI slaves\n");
2273 static inline void acpi_register_spi_devices(struct spi_controller
*ctlr
) {}
2274 #endif /* CONFIG_ACPI */
2276 static void spi_controller_release(struct device
*dev
)
2278 struct spi_controller
*ctlr
;
2280 ctlr
= container_of(dev
, struct spi_controller
, dev
);
2284 static struct class spi_master_class
= {
2285 .name
= "spi_master",
2286 .owner
= THIS_MODULE
,
2287 .dev_release
= spi_controller_release
,
2288 .dev_groups
= spi_master_groups
,
2291 #ifdef CONFIG_SPI_SLAVE
2293 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2295 * @spi: device used for the current transfer
2297 int spi_slave_abort(struct spi_device
*spi
)
2299 struct spi_controller
*ctlr
= spi
->controller
;
2301 if (spi_controller_is_slave(ctlr
) && ctlr
->slave_abort
)
2302 return ctlr
->slave_abort(ctlr
);
2306 EXPORT_SYMBOL_GPL(spi_slave_abort
);
2308 static int match_true(struct device
*dev
, void *data
)
2313 static ssize_t
slave_show(struct device
*dev
, struct device_attribute
*attr
,
2316 struct spi_controller
*ctlr
= container_of(dev
, struct spi_controller
,
2318 struct device
*child
;
2320 child
= device_find_child(&ctlr
->dev
, NULL
, match_true
);
2321 return sprintf(buf
, "%s\n",
2322 child
? to_spi_device(child
)->modalias
: NULL
);
2325 static ssize_t
slave_store(struct device
*dev
, struct device_attribute
*attr
,
2326 const char *buf
, size_t count
)
2328 struct spi_controller
*ctlr
= container_of(dev
, struct spi_controller
,
2330 struct spi_device
*spi
;
2331 struct device
*child
;
2335 rc
= sscanf(buf
, "%31s", name
);
2336 if (rc
!= 1 || !name
[0])
2339 child
= device_find_child(&ctlr
->dev
, NULL
, match_true
);
2341 /* Remove registered slave */
2342 device_unregister(child
);
2346 if (strcmp(name
, "(null)")) {
2347 /* Register new slave */
2348 spi
= spi_alloc_device(ctlr
);
2352 strlcpy(spi
->modalias
, name
, sizeof(spi
->modalias
));
2354 rc
= spi_add_device(spi
);
2364 static DEVICE_ATTR_RW(slave
);
2366 static struct attribute
*spi_slave_attrs
[] = {
2367 &dev_attr_slave
.attr
,
2371 static const struct attribute_group spi_slave_group
= {
2372 .attrs
= spi_slave_attrs
,
2375 static const struct attribute_group
*spi_slave_groups
[] = {
2376 &spi_controller_statistics_group
,
2381 static struct class spi_slave_class
= {
2382 .name
= "spi_slave",
2383 .owner
= THIS_MODULE
,
2384 .dev_release
= spi_controller_release
,
2385 .dev_groups
= spi_slave_groups
,
2388 extern struct class spi_slave_class
; /* dummy */
2392 * __spi_alloc_controller - allocate an SPI master or slave controller
2393 * @dev: the controller, possibly using the platform_bus
2394 * @size: how much zeroed driver-private data to allocate; the pointer to this
2395 * memory is in the driver_data field of the returned device, accessible
2396 * with spi_controller_get_devdata(); the memory is cacheline aligned;
2397 * drivers granting DMA access to portions of their private data need to
2398 * round up @size using ALIGN(size, dma_get_cache_alignment()).
2399 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2400 * slave (true) controller
2401 * Context: can sleep
2403 * This call is used only by SPI controller drivers, which are the
2404 * only ones directly touching chip registers. It's how they allocate
2405 * an spi_controller structure, prior to calling spi_register_controller().
2407 * This must be called from context that can sleep.
2409 * The caller is responsible for assigning the bus number and initializing the
2410 * controller's methods before calling spi_register_controller(); and (after
2411 * errors adding the device) calling spi_controller_put() to prevent a memory
2414 * Return: the SPI controller structure on success, else NULL.
2416 struct spi_controller
*__spi_alloc_controller(struct device
*dev
,
2417 unsigned int size
, bool slave
)
2419 struct spi_controller
*ctlr
;
2420 size_t ctlr_size
= ALIGN(sizeof(*ctlr
), dma_get_cache_alignment());
2425 ctlr
= kzalloc(size
+ ctlr_size
, GFP_KERNEL
);
2429 device_initialize(&ctlr
->dev
);
2431 ctlr
->num_chipselect
= 1;
2432 ctlr
->slave
= slave
;
2433 if (IS_ENABLED(CONFIG_SPI_SLAVE
) && slave
)
2434 ctlr
->dev
.class = &spi_slave_class
;
2436 ctlr
->dev
.class = &spi_master_class
;
2437 ctlr
->dev
.parent
= dev
;
2438 pm_suspend_ignore_children(&ctlr
->dev
, true);
2439 spi_controller_set_devdata(ctlr
, (void *)ctlr
+ ctlr_size
);
2443 EXPORT_SYMBOL_GPL(__spi_alloc_controller
);
2445 static void devm_spi_release_controller(struct device
*dev
, void *ctlr
)
2447 spi_controller_put(*(struct spi_controller
**)ctlr
);
2451 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
2452 * @dev: physical device of SPI controller
2453 * @size: how much zeroed driver-private data to allocate
2454 * @slave: whether to allocate an SPI master (false) or SPI slave (true)
2455 * Context: can sleep
2457 * Allocate an SPI controller and automatically release a reference on it
2458 * when @dev is unbound from its driver. Drivers are thus relieved from
2459 * having to call spi_controller_put().
2461 * The arguments to this function are identical to __spi_alloc_controller().
2463 * Return: the SPI controller structure on success, else NULL.
2465 struct spi_controller
*__devm_spi_alloc_controller(struct device
*dev
,
2469 struct spi_controller
**ptr
, *ctlr
;
2471 ptr
= devres_alloc(devm_spi_release_controller
, sizeof(*ptr
),
2476 ctlr
= __spi_alloc_controller(dev
, size
, slave
);
2479 devres_add(dev
, ptr
);
2486 EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller
);
2489 static int of_spi_get_gpio_numbers(struct spi_controller
*ctlr
)
2492 struct device_node
*np
= ctlr
->dev
.of_node
;
2497 nb
= of_gpio_named_count(np
, "cs-gpios");
2498 ctlr
->num_chipselect
= max_t(int, nb
, ctlr
->num_chipselect
);
2500 /* Return error only for an incorrectly formed cs-gpios property */
2501 if (nb
== 0 || nb
== -ENOENT
)
2506 cs
= devm_kcalloc(&ctlr
->dev
, ctlr
->num_chipselect
, sizeof(int),
2508 ctlr
->cs_gpios
= cs
;
2510 if (!ctlr
->cs_gpios
)
2513 for (i
= 0; i
< ctlr
->num_chipselect
; i
++)
2516 for (i
= 0; i
< nb
; i
++)
2517 cs
[i
] = of_get_named_gpio(np
, "cs-gpios", i
);
2522 static int of_spi_get_gpio_numbers(struct spi_controller
*ctlr
)
2529 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2530 * @ctlr: The SPI master to grab GPIO descriptors for
2532 static int spi_get_gpio_descs(struct spi_controller
*ctlr
)
2535 struct gpio_desc
**cs
;
2536 struct device
*dev
= &ctlr
->dev
;
2537 unsigned long native_cs_mask
= 0;
2538 unsigned int num_cs_gpios
= 0;
2540 nb
= gpiod_count(dev
, "cs");
2541 ctlr
->num_chipselect
= max_t(int, nb
, ctlr
->num_chipselect
);
2543 /* No GPIOs at all is fine, else return the error */
2544 if (nb
== 0 || nb
== -ENOENT
)
2549 cs
= devm_kcalloc(dev
, ctlr
->num_chipselect
, sizeof(*cs
),
2553 ctlr
->cs_gpiods
= cs
;
2555 for (i
= 0; i
< nb
; i
++) {
2557 * Most chipselects are active low, the inverted
2558 * semantics are handled by special quirks in gpiolib,
2559 * so initializing them GPIOD_OUT_LOW here means
2560 * "unasserted", in most cases this will drive the physical
2563 cs
[i
] = devm_gpiod_get_index_optional(dev
, "cs", i
,
2566 return PTR_ERR(cs
[i
]);
2570 * If we find a CS GPIO, name it after the device and
2575 gpioname
= devm_kasprintf(dev
, GFP_KERNEL
, "%s CS%d",
2579 gpiod_set_consumer_name(cs
[i
], gpioname
);
2584 if (ctlr
->max_native_cs
&& i
>= ctlr
->max_native_cs
) {
2585 dev_err(dev
, "Invalid native chip select %d\n", i
);
2588 native_cs_mask
|= BIT(i
);
2591 ctlr
->unused_native_cs
= ffz(native_cs_mask
);
2592 if (num_cs_gpios
&& ctlr
->max_native_cs
&&
2593 ctlr
->unused_native_cs
>= ctlr
->max_native_cs
) {
2594 dev_err(dev
, "No unused native chip select available\n");
2601 static int spi_controller_check_ops(struct spi_controller
*ctlr
)
2604 * The controller may implement only the high-level SPI-memory like
2605 * operations if it does not support regular SPI transfers, and this is
2607 * If ->mem_ops is NULL, we request that at least one of the
2608 * ->transfer_xxx() method be implemented.
2610 if (ctlr
->mem_ops
) {
2611 if (!ctlr
->mem_ops
->exec_op
)
2613 } else if (!ctlr
->transfer
&& !ctlr
->transfer_one
&&
2614 !ctlr
->transfer_one_message
) {
2622 * spi_register_controller - register SPI master or slave controller
2623 * @ctlr: initialized master, originally from spi_alloc_master() or
2625 * Context: can sleep
2627 * SPI controllers connect to their drivers using some non-SPI bus,
2628 * such as the platform bus. The final stage of probe() in that code
2629 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2631 * SPI controllers use board specific (often SOC specific) bus numbers,
2632 * and board-specific addressing for SPI devices combines those numbers
2633 * with chip select numbers. Since SPI does not directly support dynamic
2634 * device identification, boards need configuration tables telling which
2635 * chip is at which address.
2637 * This must be called from context that can sleep. It returns zero on
2638 * success, else a negative error code (dropping the controller's refcount).
2639 * After a successful return, the caller is responsible for calling
2640 * spi_unregister_controller().
2642 * Return: zero on success, else a negative error code.
2644 int spi_register_controller(struct spi_controller
*ctlr
)
2646 struct device
*dev
= ctlr
->dev
.parent
;
2647 struct boardinfo
*bi
;
2649 int id
, first_dynamic
;
2655 * Make sure all necessary hooks are implemented before registering
2656 * the SPI controller.
2658 status
= spi_controller_check_ops(ctlr
);
2662 if (ctlr
->bus_num
>= 0) {
2663 /* devices with a fixed bus num must check-in with the num */
2664 mutex_lock(&board_lock
);
2665 id
= idr_alloc(&spi_master_idr
, ctlr
, ctlr
->bus_num
,
2666 ctlr
->bus_num
+ 1, GFP_KERNEL
);
2667 mutex_unlock(&board_lock
);
2668 if (WARN(id
< 0, "couldn't get idr"))
2669 return id
== -ENOSPC
? -EBUSY
: id
;
2671 } else if (ctlr
->dev
.of_node
) {
2672 /* allocate dynamic bus number using Linux idr */
2673 id
= of_alias_get_id(ctlr
->dev
.of_node
, "spi");
2676 mutex_lock(&board_lock
);
2677 id
= idr_alloc(&spi_master_idr
, ctlr
, ctlr
->bus_num
,
2678 ctlr
->bus_num
+ 1, GFP_KERNEL
);
2679 mutex_unlock(&board_lock
);
2680 if (WARN(id
< 0, "couldn't get idr"))
2681 return id
== -ENOSPC
? -EBUSY
: id
;
2684 if (ctlr
->bus_num
< 0) {
2685 first_dynamic
= of_alias_get_highest_id("spi");
2686 if (first_dynamic
< 0)
2691 mutex_lock(&board_lock
);
2692 id
= idr_alloc(&spi_master_idr
, ctlr
, first_dynamic
,
2694 mutex_unlock(&board_lock
);
2695 if (WARN(id
< 0, "couldn't get idr"))
2699 INIT_LIST_HEAD(&ctlr
->queue
);
2700 spin_lock_init(&ctlr
->queue_lock
);
2701 spin_lock_init(&ctlr
->bus_lock_spinlock
);
2702 mutex_init(&ctlr
->bus_lock_mutex
);
2703 mutex_init(&ctlr
->io_mutex
);
2704 ctlr
->bus_lock_flag
= 0;
2705 init_completion(&ctlr
->xfer_completion
);
2706 if (!ctlr
->max_dma_len
)
2707 ctlr
->max_dma_len
= INT_MAX
;
2709 /* register the device, then userspace will see it.
2710 * registration fails if the bus ID is in use.
2712 dev_set_name(&ctlr
->dev
, "spi%u", ctlr
->bus_num
);
2714 if (!spi_controller_is_slave(ctlr
)) {
2715 if (ctlr
->use_gpio_descriptors
) {
2716 status
= spi_get_gpio_descs(ctlr
);
2720 * A controller using GPIO descriptors always
2721 * supports SPI_CS_HIGH if need be.
2723 ctlr
->mode_bits
|= SPI_CS_HIGH
;
2725 /* Legacy code path for GPIOs from DT */
2726 status
= of_spi_get_gpio_numbers(ctlr
);
2733 * Even if it's just one always-selected device, there must
2734 * be at least one chipselect.
2736 if (!ctlr
->num_chipselect
) {
2741 status
= device_add(&ctlr
->dev
);
2744 dev_dbg(dev
, "registered %s %s\n",
2745 spi_controller_is_slave(ctlr
) ? "slave" : "master",
2746 dev_name(&ctlr
->dev
));
2749 * If we're using a queued driver, start the queue. Note that we don't
2750 * need the queueing logic if the driver is only supporting high-level
2751 * memory operations.
2753 if (ctlr
->transfer
) {
2754 dev_info(dev
, "controller is unqueued, this is deprecated\n");
2755 } else if (ctlr
->transfer_one
|| ctlr
->transfer_one_message
) {
2756 status
= spi_controller_initialize_queue(ctlr
);
2758 device_del(&ctlr
->dev
);
2762 /* add statistics */
2763 spin_lock_init(&ctlr
->statistics
.lock
);
2765 mutex_lock(&board_lock
);
2766 list_add_tail(&ctlr
->list
, &spi_controller_list
);
2767 list_for_each_entry(bi
, &board_list
, list
)
2768 spi_match_controller_to_boardinfo(ctlr
, &bi
->board_info
);
2769 mutex_unlock(&board_lock
);
2771 /* Register devices from the device tree and ACPI */
2772 of_register_spi_devices(ctlr
);
2773 acpi_register_spi_devices(ctlr
);
2777 mutex_lock(&board_lock
);
2778 idr_remove(&spi_master_idr
, ctlr
->bus_num
);
2779 mutex_unlock(&board_lock
);
2782 EXPORT_SYMBOL_GPL(spi_register_controller
);
2784 static void devm_spi_unregister(struct device
*dev
, void *res
)
2786 spi_unregister_controller(*(struct spi_controller
**)res
);
2790 * devm_spi_register_controller - register managed SPI master or slave
2792 * @dev: device managing SPI controller
2793 * @ctlr: initialized controller, originally from spi_alloc_master() or
2795 * Context: can sleep
2797 * Register a SPI device as with spi_register_controller() which will
2798 * automatically be unregistered and freed.
2800 * Return: zero on success, else a negative error code.
2802 int devm_spi_register_controller(struct device
*dev
,
2803 struct spi_controller
*ctlr
)
2805 struct spi_controller
**ptr
;
2808 ptr
= devres_alloc(devm_spi_unregister
, sizeof(*ptr
), GFP_KERNEL
);
2812 ret
= spi_register_controller(ctlr
);
2815 devres_add(dev
, ptr
);
2822 EXPORT_SYMBOL_GPL(devm_spi_register_controller
);
2824 static int devm_spi_match_controller(struct device
*dev
, void *res
, void *ctlr
)
2826 return *(struct spi_controller
**)res
== ctlr
;
2829 static int __unregister(struct device
*dev
, void *null
)
2831 spi_unregister_device(to_spi_device(dev
));
2836 * spi_unregister_controller - unregister SPI master or slave controller
2837 * @ctlr: the controller being unregistered
2838 * Context: can sleep
2840 * This call is used only by SPI controller drivers, which are the
2841 * only ones directly touching chip registers.
2843 * This must be called from context that can sleep.
2845 * Note that this function also drops a reference to the controller.
2847 void spi_unregister_controller(struct spi_controller
*ctlr
)
2849 struct spi_controller
*found
;
2850 int id
= ctlr
->bus_num
;
2852 /* Prevent addition of new devices, unregister existing ones */
2853 if (IS_ENABLED(CONFIG_SPI_DYNAMIC
))
2854 mutex_lock(&spi_add_lock
);
2856 device_for_each_child(&ctlr
->dev
, NULL
, __unregister
);
2858 /* First make sure that this controller was ever added */
2859 mutex_lock(&board_lock
);
2860 found
= idr_find(&spi_master_idr
, id
);
2861 mutex_unlock(&board_lock
);
2863 if (spi_destroy_queue(ctlr
))
2864 dev_err(&ctlr
->dev
, "queue remove failed\n");
2866 mutex_lock(&board_lock
);
2867 list_del(&ctlr
->list
);
2868 mutex_unlock(&board_lock
);
2870 device_del(&ctlr
->dev
);
2872 /* Release the last reference on the controller if its driver
2873 * has not yet been converted to devm_spi_alloc_master/slave().
2875 if (!devres_find(ctlr
->dev
.parent
, devm_spi_release_controller
,
2876 devm_spi_match_controller
, ctlr
))
2877 put_device(&ctlr
->dev
);
2880 mutex_lock(&board_lock
);
2882 idr_remove(&spi_master_idr
, id
);
2883 mutex_unlock(&board_lock
);
2885 if (IS_ENABLED(CONFIG_SPI_DYNAMIC
))
2886 mutex_unlock(&spi_add_lock
);
2888 EXPORT_SYMBOL_GPL(spi_unregister_controller
);
2890 int spi_controller_suspend(struct spi_controller
*ctlr
)
2894 /* Basically no-ops for non-queued controllers */
2898 ret
= spi_stop_queue(ctlr
);
2900 dev_err(&ctlr
->dev
, "queue stop failed\n");
2904 EXPORT_SYMBOL_GPL(spi_controller_suspend
);
2906 int spi_controller_resume(struct spi_controller
*ctlr
)
2913 ret
= spi_start_queue(ctlr
);
2915 dev_err(&ctlr
->dev
, "queue restart failed\n");
2919 EXPORT_SYMBOL_GPL(spi_controller_resume
);
2921 static int __spi_controller_match(struct device
*dev
, const void *data
)
2923 struct spi_controller
*ctlr
;
2924 const u16
*bus_num
= data
;
2926 ctlr
= container_of(dev
, struct spi_controller
, dev
);
2927 return ctlr
->bus_num
== *bus_num
;
2931 * spi_busnum_to_master - look up master associated with bus_num
2932 * @bus_num: the master's bus number
2933 * Context: can sleep
2935 * This call may be used with devices that are registered after
2936 * arch init time. It returns a refcounted pointer to the relevant
2937 * spi_controller (which the caller must release), or NULL if there is
2938 * no such master registered.
2940 * Return: the SPI master structure on success, else NULL.
2942 struct spi_controller
*spi_busnum_to_master(u16 bus_num
)
2945 struct spi_controller
*ctlr
= NULL
;
2947 dev
= class_find_device(&spi_master_class
, NULL
, &bus_num
,
2948 __spi_controller_match
);
2950 ctlr
= container_of(dev
, struct spi_controller
, dev
);
2951 /* reference got in class_find_device */
2954 EXPORT_SYMBOL_GPL(spi_busnum_to_master
);
2956 /*-------------------------------------------------------------------------*/
2958 /* Core methods for SPI resource management */
2961 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2962 * during the processing of a spi_message while using
2964 * @spi: the spi device for which we allocate memory
2965 * @release: the release code to execute for this resource
2966 * @size: size to alloc and return
2967 * @gfp: GFP allocation flags
2969 * Return: the pointer to the allocated data
2971 * This may get enhanced in the future to allocate from a memory pool
2972 * of the @spi_device or @spi_controller to avoid repeated allocations.
2974 void *spi_res_alloc(struct spi_device
*spi
,
2975 spi_res_release_t release
,
2976 size_t size
, gfp_t gfp
)
2978 struct spi_res
*sres
;
2980 sres
= kzalloc(sizeof(*sres
) + size
, gfp
);
2984 INIT_LIST_HEAD(&sres
->entry
);
2985 sres
->release
= release
;
2989 EXPORT_SYMBOL_GPL(spi_res_alloc
);
2992 * spi_res_free - free an spi resource
2993 * @res: pointer to the custom data of a resource
2996 void spi_res_free(void *res
)
2998 struct spi_res
*sres
= container_of(res
, struct spi_res
, data
);
3003 WARN_ON(!list_empty(&sres
->entry
));
3006 EXPORT_SYMBOL_GPL(spi_res_free
);
3009 * spi_res_add - add a spi_res to the spi_message
3010 * @message: the spi message
3011 * @res: the spi_resource
3013 void spi_res_add(struct spi_message
*message
, void *res
)
3015 struct spi_res
*sres
= container_of(res
, struct spi_res
, data
);
3017 WARN_ON(!list_empty(&sres
->entry
));
3018 list_add_tail(&sres
->entry
, &message
->resources
);
3020 EXPORT_SYMBOL_GPL(spi_res_add
);
3023 * spi_res_release - release all spi resources for this message
3024 * @ctlr: the @spi_controller
3025 * @message: the @spi_message
3027 void spi_res_release(struct spi_controller
*ctlr
, struct spi_message
*message
)
3029 struct spi_res
*res
, *tmp
;
3031 list_for_each_entry_safe_reverse(res
, tmp
, &message
->resources
, entry
) {
3033 res
->release(ctlr
, message
, res
->data
);
3035 list_del(&res
->entry
);
3040 EXPORT_SYMBOL_GPL(spi_res_release
);
3042 /*-------------------------------------------------------------------------*/
3044 /* Core methods for spi_message alterations */
3046 static void __spi_replace_transfers_release(struct spi_controller
*ctlr
,
3047 struct spi_message
*msg
,
3050 struct spi_replaced_transfers
*rxfer
= res
;
3053 /* call extra callback if requested */
3055 rxfer
->release(ctlr
, msg
, res
);
3057 /* insert replaced transfers back into the message */
3058 list_splice(&rxfer
->replaced_transfers
, rxfer
->replaced_after
);
3060 /* remove the formerly inserted entries */
3061 for (i
= 0; i
< rxfer
->inserted
; i
++)
3062 list_del(&rxfer
->inserted_transfers
[i
].transfer_list
);
3066 * spi_replace_transfers - replace transfers with several transfers
3067 * and register change with spi_message.resources
3068 * @msg: the spi_message we work upon
3069 * @xfer_first: the first spi_transfer we want to replace
3070 * @remove: number of transfers to remove
3071 * @insert: the number of transfers we want to insert instead
3072 * @release: extra release code necessary in some circumstances
3073 * @extradatasize: extra data to allocate (with alignment guarantees
3074 * of struct @spi_transfer)
3077 * Returns: pointer to @spi_replaced_transfers,
3078 * PTR_ERR(...) in case of errors.
3080 struct spi_replaced_transfers
*spi_replace_transfers(
3081 struct spi_message
*msg
,
3082 struct spi_transfer
*xfer_first
,
3085 spi_replaced_release_t release
,
3086 size_t extradatasize
,
3089 struct spi_replaced_transfers
*rxfer
;
3090 struct spi_transfer
*xfer
;
3093 /* allocate the structure using spi_res */
3094 rxfer
= spi_res_alloc(msg
->spi
, __spi_replace_transfers_release
,
3095 struct_size(rxfer
, inserted_transfers
, insert
)
3099 return ERR_PTR(-ENOMEM
);
3101 /* the release code to invoke before running the generic release */
3102 rxfer
->release
= release
;
3104 /* assign extradata */
3107 &rxfer
->inserted_transfers
[insert
];
3109 /* init the replaced_transfers list */
3110 INIT_LIST_HEAD(&rxfer
->replaced_transfers
);
3112 /* assign the list_entry after which we should reinsert
3113 * the @replaced_transfers - it may be spi_message.messages!
3115 rxfer
->replaced_after
= xfer_first
->transfer_list
.prev
;
3117 /* remove the requested number of transfers */
3118 for (i
= 0; i
< remove
; i
++) {
3119 /* if the entry after replaced_after it is msg->transfers
3120 * then we have been requested to remove more transfers
3121 * than are in the list
3123 if (rxfer
->replaced_after
->next
== &msg
->transfers
) {
3124 dev_err(&msg
->spi
->dev
,
3125 "requested to remove more spi_transfers than are available\n");
3126 /* insert replaced transfers back into the message */
3127 list_splice(&rxfer
->replaced_transfers
,
3128 rxfer
->replaced_after
);
3130 /* free the spi_replace_transfer structure */
3131 spi_res_free(rxfer
);
3133 /* and return with an error */
3134 return ERR_PTR(-EINVAL
);
3137 /* remove the entry after replaced_after from list of
3138 * transfers and add it to list of replaced_transfers
3140 list_move_tail(rxfer
->replaced_after
->next
,
3141 &rxfer
->replaced_transfers
);
3144 /* create copy of the given xfer with identical settings
3145 * based on the first transfer to get removed
3147 for (i
= 0; i
< insert
; i
++) {
3148 /* we need to run in reverse order */
3149 xfer
= &rxfer
->inserted_transfers
[insert
- 1 - i
];
3151 /* copy all spi_transfer data */
3152 memcpy(xfer
, xfer_first
, sizeof(*xfer
));
3155 list_add(&xfer
->transfer_list
, rxfer
->replaced_after
);
3157 /* clear cs_change and delay for all but the last */
3159 xfer
->cs_change
= false;
3160 xfer
->delay_usecs
= 0;
3161 xfer
->delay
.value
= 0;
3165 /* set up inserted */
3166 rxfer
->inserted
= insert
;
3168 /* and register it with spi_res/spi_message */
3169 spi_res_add(msg
, rxfer
);
3173 EXPORT_SYMBOL_GPL(spi_replace_transfers
);
3175 static int __spi_split_transfer_maxsize(struct spi_controller
*ctlr
,
3176 struct spi_message
*msg
,
3177 struct spi_transfer
**xferp
,
3181 struct spi_transfer
*xfer
= *xferp
, *xfers
;
3182 struct spi_replaced_transfers
*srt
;
3186 /* calculate how many we have to replace */
3187 count
= DIV_ROUND_UP(xfer
->len
, maxsize
);
3189 /* create replacement */
3190 srt
= spi_replace_transfers(msg
, xfer
, 1, count
, NULL
, 0, gfp
);
3192 return PTR_ERR(srt
);
3193 xfers
= srt
->inserted_transfers
;
3195 /* now handle each of those newly inserted spi_transfers
3196 * note that the replacements spi_transfers all are preset
3197 * to the same values as *xferp, so tx_buf, rx_buf and len
3198 * are all identical (as well as most others)
3199 * so we just have to fix up len and the pointers.
3201 * this also includes support for the depreciated
3202 * spi_message.is_dma_mapped interface
3205 /* the first transfer just needs the length modified, so we
3206 * run it outside the loop
3208 xfers
[0].len
= min_t(size_t, maxsize
, xfer
[0].len
);
3210 /* all the others need rx_buf/tx_buf also set */
3211 for (i
= 1, offset
= maxsize
; i
< count
; offset
+= maxsize
, i
++) {
3212 /* update rx_buf, tx_buf and dma */
3213 if (xfers
[i
].rx_buf
)
3214 xfers
[i
].rx_buf
+= offset
;
3215 if (xfers
[i
].rx_dma
)
3216 xfers
[i
].rx_dma
+= offset
;
3217 if (xfers
[i
].tx_buf
)
3218 xfers
[i
].tx_buf
+= offset
;
3219 if (xfers
[i
].tx_dma
)
3220 xfers
[i
].tx_dma
+= offset
;
3223 xfers
[i
].len
= min(maxsize
, xfers
[i
].len
- offset
);
3226 /* we set up xferp to the last entry we have inserted,
3227 * so that we skip those already split transfers
3229 *xferp
= &xfers
[count
- 1];
3231 /* increment statistics counters */
3232 SPI_STATISTICS_INCREMENT_FIELD(&ctlr
->statistics
,
3233 transfers_split_maxsize
);
3234 SPI_STATISTICS_INCREMENT_FIELD(&msg
->spi
->statistics
,
3235 transfers_split_maxsize
);
3241 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
3242 * when an individual transfer exceeds a
3244 * @ctlr: the @spi_controller for this transfer
3245 * @msg: the @spi_message to transform
3246 * @maxsize: the maximum when to apply this
3247 * @gfp: GFP allocation flags
3249 * Return: status of transformation
3251 int spi_split_transfers_maxsize(struct spi_controller
*ctlr
,
3252 struct spi_message
*msg
,
3256 struct spi_transfer
*xfer
;
3259 /* iterate over the transfer_list,
3260 * but note that xfer is advanced to the last transfer inserted
3261 * to avoid checking sizes again unnecessarily (also xfer does
3262 * potentiall belong to a different list by the time the
3263 * replacement has happened
3265 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
3266 if (xfer
->len
> maxsize
) {
3267 ret
= __spi_split_transfer_maxsize(ctlr
, msg
, &xfer
,
3276 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize
);
3278 /*-------------------------------------------------------------------------*/
3280 /* Core methods for SPI controller protocol drivers. Some of the
3281 * other core methods are currently defined as inline functions.
3284 static int __spi_validate_bits_per_word(struct spi_controller
*ctlr
,
3287 if (ctlr
->bits_per_word_mask
) {
3288 /* Only 32 bits fit in the mask */
3289 if (bits_per_word
> 32)
3291 if (!(ctlr
->bits_per_word_mask
& SPI_BPW_MASK(bits_per_word
)))
3299 * spi_setup - setup SPI mode and clock rate
3300 * @spi: the device whose settings are being modified
3301 * Context: can sleep, and no requests are queued to the device
3303 * SPI protocol drivers may need to update the transfer mode if the
3304 * device doesn't work with its default. They may likewise need
3305 * to update clock rates or word sizes from initial values. This function
3306 * changes those settings, and must be called from a context that can sleep.
3307 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3308 * effect the next time the device is selected and data is transferred to
3309 * or from it. When this function returns, the spi device is deselected.
3311 * Note that this call will fail if the protocol driver specifies an option
3312 * that the underlying controller or its driver does not support. For
3313 * example, not all hardware supports wire transfers using nine bit words,
3314 * LSB-first wire encoding, or active-high chipselects.
3316 * Return: zero on success, else a negative error code.
3318 int spi_setup(struct spi_device
*spi
)
3320 unsigned bad_bits
, ugly_bits
;
3323 /* check mode to prevent that DUAL and QUAD set at the same time
3325 if (((spi
->mode
& SPI_TX_DUAL
) && (spi
->mode
& SPI_TX_QUAD
)) ||
3326 ((spi
->mode
& SPI_RX_DUAL
) && (spi
->mode
& SPI_RX_QUAD
))) {
3328 "setup: can not select dual and quad at the same time\n");
3331 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
3333 if ((spi
->mode
& SPI_3WIRE
) && (spi
->mode
&
3334 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_TX_OCTAL
|
3335 SPI_RX_DUAL
| SPI_RX_QUAD
| SPI_RX_OCTAL
)))
3337 /* help drivers fail *cleanly* when they need options
3338 * that aren't supported with their current controller
3339 * SPI_CS_WORD has a fallback software implementation,
3340 * so it is ignored here.
3342 bad_bits
= spi
->mode
& ~(spi
->controller
->mode_bits
| SPI_CS_WORD
);
3343 /* nothing prevents from working with active-high CS in case if it
3344 * is driven by GPIO.
3346 if (gpio_is_valid(spi
->cs_gpio
))
3347 bad_bits
&= ~SPI_CS_HIGH
;
3348 ugly_bits
= bad_bits
&
3349 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_TX_OCTAL
|
3350 SPI_RX_DUAL
| SPI_RX_QUAD
| SPI_RX_OCTAL
);
3353 "setup: ignoring unsupported mode bits %x\n",
3355 spi
->mode
&= ~ugly_bits
;
3356 bad_bits
&= ~ugly_bits
;
3359 dev_err(&spi
->dev
, "setup: unsupported mode bits %x\n",
3364 if (!spi
->bits_per_word
)
3365 spi
->bits_per_word
= 8;
3367 status
= __spi_validate_bits_per_word(spi
->controller
,
3368 spi
->bits_per_word
);
3372 if (!spi
->max_speed_hz
)
3373 spi
->max_speed_hz
= spi
->controller
->max_speed_hz
;
3375 if (spi
->controller
->setup
)
3376 status
= spi
->controller
->setup(spi
);
3378 if (spi
->controller
->auto_runtime_pm
&& spi
->controller
->set_cs
) {
3379 status
= pm_runtime_get_sync(spi
->controller
->dev
.parent
);
3381 pm_runtime_put_noidle(spi
->controller
->dev
.parent
);
3382 dev_err(&spi
->controller
->dev
, "Failed to power device: %d\n",
3388 * We do not want to return positive value from pm_runtime_get,
3389 * there are many instances of devices calling spi_setup() and
3390 * checking for a non-zero return value instead of a negative
3395 spi_set_cs(spi
, false);
3396 pm_runtime_mark_last_busy(spi
->controller
->dev
.parent
);
3397 pm_runtime_put_autosuspend(spi
->controller
->dev
.parent
);
3399 spi_set_cs(spi
, false);
3402 if (spi
->rt
&& !spi
->controller
->rt
) {
3403 spi
->controller
->rt
= true;
3404 spi_set_thread_rt(spi
->controller
);
3407 dev_dbg(&spi
->dev
, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3408 (int) (spi
->mode
& (SPI_CPOL
| SPI_CPHA
)),
3409 (spi
->mode
& SPI_CS_HIGH
) ? "cs_high, " : "",
3410 (spi
->mode
& SPI_LSB_FIRST
) ? "lsb, " : "",
3411 (spi
->mode
& SPI_3WIRE
) ? "3wire, " : "",
3412 (spi
->mode
& SPI_LOOP
) ? "loopback, " : "",
3413 spi
->bits_per_word
, spi
->max_speed_hz
,
3418 EXPORT_SYMBOL_GPL(spi_setup
);
3421 * spi_set_cs_timing - configure CS setup, hold, and inactive delays
3422 * @spi: the device that requires specific CS timing configuration
3423 * @setup: CS setup time specified via @spi_delay
3424 * @hold: CS hold time specified via @spi_delay
3425 * @inactive: CS inactive delay between transfers specified via @spi_delay
3427 * Return: zero on success, else a negative error code.
3429 int spi_set_cs_timing(struct spi_device
*spi
, struct spi_delay
*setup
,
3430 struct spi_delay
*hold
, struct spi_delay
*inactive
)
3434 if (spi
->controller
->set_cs_timing
)
3435 return spi
->controller
->set_cs_timing(spi
, setup
, hold
,
3438 if ((setup
&& setup
->unit
== SPI_DELAY_UNIT_SCK
) ||
3439 (hold
&& hold
->unit
== SPI_DELAY_UNIT_SCK
) ||
3440 (inactive
&& inactive
->unit
== SPI_DELAY_UNIT_SCK
)) {
3442 "Clock-cycle delays for CS not supported in SW mode\n");
3446 len
= sizeof(struct spi_delay
);
3448 /* copy delays to controller */
3450 memcpy(&spi
->controller
->cs_setup
, setup
, len
);
3452 memset(&spi
->controller
->cs_setup
, 0, len
);
3455 memcpy(&spi
->controller
->cs_hold
, hold
, len
);
3457 memset(&spi
->controller
->cs_hold
, 0, len
);
3460 memcpy(&spi
->controller
->cs_inactive
, inactive
, len
);
3462 memset(&spi
->controller
->cs_inactive
, 0, len
);
3466 EXPORT_SYMBOL_GPL(spi_set_cs_timing
);
3468 static int _spi_xfer_word_delay_update(struct spi_transfer
*xfer
,
3469 struct spi_device
*spi
)
3473 delay1
= spi_delay_to_ns(&xfer
->word_delay
, xfer
);
3477 delay2
= spi_delay_to_ns(&spi
->word_delay
, xfer
);
3481 if (delay1
< delay2
)
3482 memcpy(&xfer
->word_delay
, &spi
->word_delay
,
3483 sizeof(xfer
->word_delay
));
3488 static int __spi_validate(struct spi_device
*spi
, struct spi_message
*message
)
3490 struct spi_controller
*ctlr
= spi
->controller
;
3491 struct spi_transfer
*xfer
;
3494 if (list_empty(&message
->transfers
))
3497 /* If an SPI controller does not support toggling the CS line on each
3498 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3499 * for the CS line, we can emulate the CS-per-word hardware function by
3500 * splitting transfers into one-word transfers and ensuring that
3501 * cs_change is set for each transfer.
3503 if ((spi
->mode
& SPI_CS_WORD
) && (!(ctlr
->mode_bits
& SPI_CS_WORD
) ||
3505 gpio_is_valid(spi
->cs_gpio
))) {
3509 maxsize
= (spi
->bits_per_word
+ 7) / 8;
3511 /* spi_split_transfers_maxsize() requires message->spi */
3514 ret
= spi_split_transfers_maxsize(ctlr
, message
, maxsize
,
3519 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
3520 /* don't change cs_change on the last entry in the list */
3521 if (list_is_last(&xfer
->transfer_list
, &message
->transfers
))
3523 xfer
->cs_change
= 1;
3527 /* Half-duplex links include original MicroWire, and ones with
3528 * only one data pin like SPI_3WIRE (switches direction) or where
3529 * either MOSI or MISO is missing. They can also be caused by
3530 * software limitations.
3532 if ((ctlr
->flags
& SPI_CONTROLLER_HALF_DUPLEX
) ||
3533 (spi
->mode
& SPI_3WIRE
)) {
3534 unsigned flags
= ctlr
->flags
;
3536 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
3537 if (xfer
->rx_buf
&& xfer
->tx_buf
)
3539 if ((flags
& SPI_CONTROLLER_NO_TX
) && xfer
->tx_buf
)
3541 if ((flags
& SPI_CONTROLLER_NO_RX
) && xfer
->rx_buf
)
3547 * Set transfer bits_per_word and max speed as spi device default if
3548 * it is not set for this transfer.
3549 * Set transfer tx_nbits and rx_nbits as single transfer default
3550 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3551 * Ensure transfer word_delay is at least as long as that required by
3554 message
->frame_length
= 0;
3555 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
3556 xfer
->effective_speed_hz
= 0;
3557 message
->frame_length
+= xfer
->len
;
3558 if (!xfer
->bits_per_word
)
3559 xfer
->bits_per_word
= spi
->bits_per_word
;
3561 if (!xfer
->speed_hz
)
3562 xfer
->speed_hz
= spi
->max_speed_hz
;
3564 if (ctlr
->max_speed_hz
&& xfer
->speed_hz
> ctlr
->max_speed_hz
)
3565 xfer
->speed_hz
= ctlr
->max_speed_hz
;
3567 if (__spi_validate_bits_per_word(ctlr
, xfer
->bits_per_word
))
3571 * SPI transfer length should be multiple of SPI word size
3572 * where SPI word size should be power-of-two multiple
3574 if (xfer
->bits_per_word
<= 8)
3576 else if (xfer
->bits_per_word
<= 16)
3581 /* No partial transfers accepted */
3582 if (xfer
->len
% w_size
)
3585 if (xfer
->speed_hz
&& ctlr
->min_speed_hz
&&
3586 xfer
->speed_hz
< ctlr
->min_speed_hz
)
3589 if (xfer
->tx_buf
&& !xfer
->tx_nbits
)
3590 xfer
->tx_nbits
= SPI_NBITS_SINGLE
;
3591 if (xfer
->rx_buf
&& !xfer
->rx_nbits
)
3592 xfer
->rx_nbits
= SPI_NBITS_SINGLE
;
3593 /* check transfer tx/rx_nbits:
3594 * 1. check the value matches one of single, dual and quad
3595 * 2. check tx/rx_nbits match the mode in spi_device
3598 if (xfer
->tx_nbits
!= SPI_NBITS_SINGLE
&&
3599 xfer
->tx_nbits
!= SPI_NBITS_DUAL
&&
3600 xfer
->tx_nbits
!= SPI_NBITS_QUAD
)
3602 if ((xfer
->tx_nbits
== SPI_NBITS_DUAL
) &&
3603 !(spi
->mode
& (SPI_TX_DUAL
| SPI_TX_QUAD
)))
3605 if ((xfer
->tx_nbits
== SPI_NBITS_QUAD
) &&
3606 !(spi
->mode
& SPI_TX_QUAD
))
3609 /* check transfer rx_nbits */
3611 if (xfer
->rx_nbits
!= SPI_NBITS_SINGLE
&&
3612 xfer
->rx_nbits
!= SPI_NBITS_DUAL
&&
3613 xfer
->rx_nbits
!= SPI_NBITS_QUAD
)
3615 if ((xfer
->rx_nbits
== SPI_NBITS_DUAL
) &&
3616 !(spi
->mode
& (SPI_RX_DUAL
| SPI_RX_QUAD
)))
3618 if ((xfer
->rx_nbits
== SPI_NBITS_QUAD
) &&
3619 !(spi
->mode
& SPI_RX_QUAD
))
3623 if (_spi_xfer_word_delay_update(xfer
, spi
))
3627 message
->status
= -EINPROGRESS
;
3632 static int __spi_async(struct spi_device
*spi
, struct spi_message
*message
)
3634 struct spi_controller
*ctlr
= spi
->controller
;
3635 struct spi_transfer
*xfer
;
3638 * Some controllers do not support doing regular SPI transfers. Return
3639 * ENOTSUPP when this is the case.
3641 if (!ctlr
->transfer
)
3646 SPI_STATISTICS_INCREMENT_FIELD(&ctlr
->statistics
, spi_async
);
3647 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
, spi_async
);
3649 trace_spi_message_submit(message
);
3651 if (!ctlr
->ptp_sts_supported
) {
3652 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
3653 xfer
->ptp_sts_word_pre
= 0;
3654 ptp_read_system_prets(xfer
->ptp_sts
);
3658 return ctlr
->transfer(spi
, message
);
3662 * spi_async - asynchronous SPI transfer
3663 * @spi: device with which data will be exchanged
3664 * @message: describes the data transfers, including completion callback
3665 * Context: any (irqs may be blocked, etc)
3667 * This call may be used in_irq and other contexts which can't sleep,
3668 * as well as from task contexts which can sleep.
3670 * The completion callback is invoked in a context which can't sleep.
3671 * Before that invocation, the value of message->status is undefined.
3672 * When the callback is issued, message->status holds either zero (to
3673 * indicate complete success) or a negative error code. After that
3674 * callback returns, the driver which issued the transfer request may
3675 * deallocate the associated memory; it's no longer in use by any SPI
3676 * core or controller driver code.
3678 * Note that although all messages to a spi_device are handled in
3679 * FIFO order, messages may go to different devices in other orders.
3680 * Some device might be higher priority, or have various "hard" access
3681 * time requirements, for example.
3683 * On detection of any fault during the transfer, processing of
3684 * the entire message is aborted, and the device is deselected.
3685 * Until returning from the associated message completion callback,
3686 * no other spi_message queued to that device will be processed.
3687 * (This rule applies equally to all the synchronous transfer calls,
3688 * which are wrappers around this core asynchronous primitive.)
3690 * Return: zero on success, else a negative error code.
3692 int spi_async(struct spi_device
*spi
, struct spi_message
*message
)
3694 struct spi_controller
*ctlr
= spi
->controller
;
3696 unsigned long flags
;
3698 ret
= __spi_validate(spi
, message
);
3702 spin_lock_irqsave(&ctlr
->bus_lock_spinlock
, flags
);
3704 if (ctlr
->bus_lock_flag
)
3707 ret
= __spi_async(spi
, message
);
3709 spin_unlock_irqrestore(&ctlr
->bus_lock_spinlock
, flags
);
3713 EXPORT_SYMBOL_GPL(spi_async
);
3716 * spi_async_locked - version of spi_async with exclusive bus usage
3717 * @spi: device with which data will be exchanged
3718 * @message: describes the data transfers, including completion callback
3719 * Context: any (irqs may be blocked, etc)
3721 * This call may be used in_irq and other contexts which can't sleep,
3722 * as well as from task contexts which can sleep.
3724 * The completion callback is invoked in a context which can't sleep.
3725 * Before that invocation, the value of message->status is undefined.
3726 * When the callback is issued, message->status holds either zero (to
3727 * indicate complete success) or a negative error code. After that
3728 * callback returns, the driver which issued the transfer request may
3729 * deallocate the associated memory; it's no longer in use by any SPI
3730 * core or controller driver code.
3732 * Note that although all messages to a spi_device are handled in
3733 * FIFO order, messages may go to different devices in other orders.
3734 * Some device might be higher priority, or have various "hard" access
3735 * time requirements, for example.
3737 * On detection of any fault during the transfer, processing of
3738 * the entire message is aborted, and the device is deselected.
3739 * Until returning from the associated message completion callback,
3740 * no other spi_message queued to that device will be processed.
3741 * (This rule applies equally to all the synchronous transfer calls,
3742 * which are wrappers around this core asynchronous primitive.)
3744 * Return: zero on success, else a negative error code.
3746 int spi_async_locked(struct spi_device
*spi
, struct spi_message
*message
)
3748 struct spi_controller
*ctlr
= spi
->controller
;
3750 unsigned long flags
;
3752 ret
= __spi_validate(spi
, message
);
3756 spin_lock_irqsave(&ctlr
->bus_lock_spinlock
, flags
);
3758 ret
= __spi_async(spi
, message
);
3760 spin_unlock_irqrestore(&ctlr
->bus_lock_spinlock
, flags
);
3765 EXPORT_SYMBOL_GPL(spi_async_locked
);
3767 /*-------------------------------------------------------------------------*/
3769 /* Utility methods for SPI protocol drivers, layered on
3770 * top of the core. Some other utility methods are defined as
3774 static void spi_complete(void *arg
)
3779 static int __spi_sync(struct spi_device
*spi
, struct spi_message
*message
)
3781 DECLARE_COMPLETION_ONSTACK(done
);
3783 struct spi_controller
*ctlr
= spi
->controller
;
3784 unsigned long flags
;
3786 status
= __spi_validate(spi
, message
);
3790 message
->complete
= spi_complete
;
3791 message
->context
= &done
;
3794 SPI_STATISTICS_INCREMENT_FIELD(&ctlr
->statistics
, spi_sync
);
3795 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
, spi_sync
);
3797 /* If we're not using the legacy transfer method then we will
3798 * try to transfer in the calling context so special case.
3799 * This code would be less tricky if we could remove the
3800 * support for driver implemented message queues.
3802 if (ctlr
->transfer
== spi_queued_transfer
) {
3803 spin_lock_irqsave(&ctlr
->bus_lock_spinlock
, flags
);
3805 trace_spi_message_submit(message
);
3807 status
= __spi_queued_transfer(spi
, message
, false);
3809 spin_unlock_irqrestore(&ctlr
->bus_lock_spinlock
, flags
);
3811 status
= spi_async_locked(spi
, message
);
3815 /* Push out the messages in the calling context if we
3818 if (ctlr
->transfer
== spi_queued_transfer
) {
3819 SPI_STATISTICS_INCREMENT_FIELD(&ctlr
->statistics
,
3820 spi_sync_immediate
);
3821 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
,
3822 spi_sync_immediate
);
3823 __spi_pump_messages(ctlr
, false);
3826 wait_for_completion(&done
);
3827 status
= message
->status
;
3829 message
->context
= NULL
;
3834 * spi_sync - blocking/synchronous SPI data transfers
3835 * @spi: device with which data will be exchanged
3836 * @message: describes the data transfers
3837 * Context: can sleep
3839 * This call may only be used from a context that may sleep. The sleep
3840 * is non-interruptible, and has no timeout. Low-overhead controller
3841 * drivers may DMA directly into and out of the message buffers.
3843 * Note that the SPI device's chip select is active during the message,
3844 * and then is normally disabled between messages. Drivers for some
3845 * frequently-used devices may want to minimize costs of selecting a chip,
3846 * by leaving it selected in anticipation that the next message will go
3847 * to the same chip. (That may increase power usage.)
3849 * Also, the caller is guaranteeing that the memory associated with the
3850 * message will not be freed before this call returns.
3852 * Return: zero on success, else a negative error code.
3854 int spi_sync(struct spi_device
*spi
, struct spi_message
*message
)
3858 mutex_lock(&spi
->controller
->bus_lock_mutex
);
3859 ret
= __spi_sync(spi
, message
);
3860 mutex_unlock(&spi
->controller
->bus_lock_mutex
);
3864 EXPORT_SYMBOL_GPL(spi_sync
);
3867 * spi_sync_locked - version of spi_sync with exclusive bus usage
3868 * @spi: device with which data will be exchanged
3869 * @message: describes the data transfers
3870 * Context: can sleep
3872 * This call may only be used from a context that may sleep. The sleep
3873 * is non-interruptible, and has no timeout. Low-overhead controller
3874 * drivers may DMA directly into and out of the message buffers.
3876 * This call should be used by drivers that require exclusive access to the
3877 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3878 * be released by a spi_bus_unlock call when the exclusive access is over.
3880 * Return: zero on success, else a negative error code.
3882 int spi_sync_locked(struct spi_device
*spi
, struct spi_message
*message
)
3884 return __spi_sync(spi
, message
);
3886 EXPORT_SYMBOL_GPL(spi_sync_locked
);
3889 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3890 * @ctlr: SPI bus master that should be locked for exclusive bus access
3891 * Context: can sleep
3893 * This call may only be used from a context that may sleep. The sleep
3894 * is non-interruptible, and has no timeout.
3896 * This call should be used by drivers that require exclusive access to the
3897 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3898 * exclusive access is over. Data transfer must be done by spi_sync_locked
3899 * and spi_async_locked calls when the SPI bus lock is held.
3901 * Return: always zero.
3903 int spi_bus_lock(struct spi_controller
*ctlr
)
3905 unsigned long flags
;
3907 mutex_lock(&ctlr
->bus_lock_mutex
);
3909 spin_lock_irqsave(&ctlr
->bus_lock_spinlock
, flags
);
3910 ctlr
->bus_lock_flag
= 1;
3911 spin_unlock_irqrestore(&ctlr
->bus_lock_spinlock
, flags
);
3913 /* mutex remains locked until spi_bus_unlock is called */
3917 EXPORT_SYMBOL_GPL(spi_bus_lock
);
3920 * spi_bus_unlock - release the lock for exclusive SPI bus usage
3921 * @ctlr: SPI bus master that was locked for exclusive bus access
3922 * Context: can sleep
3924 * This call may only be used from a context that may sleep. The sleep
3925 * is non-interruptible, and has no timeout.
3927 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3930 * Return: always zero.
3932 int spi_bus_unlock(struct spi_controller
*ctlr
)
3934 ctlr
->bus_lock_flag
= 0;
3936 mutex_unlock(&ctlr
->bus_lock_mutex
);
3940 EXPORT_SYMBOL_GPL(spi_bus_unlock
);
3942 /* portable code must never pass more than 32 bytes */
3943 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3948 * spi_write_then_read - SPI synchronous write followed by read
3949 * @spi: device with which data will be exchanged
3950 * @txbuf: data to be written (need not be dma-safe)
3951 * @n_tx: size of txbuf, in bytes
3952 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3953 * @n_rx: size of rxbuf, in bytes
3954 * Context: can sleep
3956 * This performs a half duplex MicroWire style transaction with the
3957 * device, sending txbuf and then reading rxbuf. The return value
3958 * is zero for success, else a negative errno status code.
3959 * This call may only be used from a context that may sleep.
3961 * Parameters to this routine are always copied using a small buffer.
3962 * Performance-sensitive or bulk transfer code should instead use
3963 * spi_{async,sync}() calls with dma-safe buffers.
3965 * Return: zero on success, else a negative error code.
3967 int spi_write_then_read(struct spi_device
*spi
,
3968 const void *txbuf
, unsigned n_tx
,
3969 void *rxbuf
, unsigned n_rx
)
3971 static DEFINE_MUTEX(lock
);
3974 struct spi_message message
;
3975 struct spi_transfer x
[2];
3978 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3979 * copying here, (as a pure convenience thing), but we can
3980 * keep heap costs out of the hot path unless someone else is
3981 * using the pre-allocated buffer or the transfer is too large.
3983 if ((n_tx
+ n_rx
) > SPI_BUFSIZ
|| !mutex_trylock(&lock
)) {
3984 local_buf
= kmalloc(max((unsigned)SPI_BUFSIZ
, n_tx
+ n_rx
),
3985 GFP_KERNEL
| GFP_DMA
);
3992 spi_message_init(&message
);
3993 memset(x
, 0, sizeof(x
));
3996 spi_message_add_tail(&x
[0], &message
);
4000 spi_message_add_tail(&x
[1], &message
);
4003 memcpy(local_buf
, txbuf
, n_tx
);
4004 x
[0].tx_buf
= local_buf
;
4005 x
[1].rx_buf
= local_buf
+ n_tx
;
4008 status
= spi_sync(spi
, &message
);
4010 memcpy(rxbuf
, x
[1].rx_buf
, n_rx
);
4012 if (x
[0].tx_buf
== buf
)
4013 mutex_unlock(&lock
);
4019 EXPORT_SYMBOL_GPL(spi_write_then_read
);
4021 /*-------------------------------------------------------------------------*/
4023 #if IS_ENABLED(CONFIG_OF)
4024 /* must call put_device() when done with returned spi_device device */
4025 struct spi_device
*of_find_spi_device_by_node(struct device_node
*node
)
4027 struct device
*dev
= bus_find_device_by_of_node(&spi_bus_type
, node
);
4029 return dev
? to_spi_device(dev
) : NULL
;
4031 EXPORT_SYMBOL_GPL(of_find_spi_device_by_node
);
4032 #endif /* IS_ENABLED(CONFIG_OF) */
4034 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
4035 /* the spi controllers are not using spi_bus, so we find it with another way */
4036 static struct spi_controller
*of_find_spi_controller_by_node(struct device_node
*node
)
4040 dev
= class_find_device_by_of_node(&spi_master_class
, node
);
4041 if (!dev
&& IS_ENABLED(CONFIG_SPI_SLAVE
))
4042 dev
= class_find_device_by_of_node(&spi_slave_class
, node
);
4046 /* reference got in class_find_device */
4047 return container_of(dev
, struct spi_controller
, dev
);
4050 static int of_spi_notify(struct notifier_block
*nb
, unsigned long action
,
4053 struct of_reconfig_data
*rd
= arg
;
4054 struct spi_controller
*ctlr
;
4055 struct spi_device
*spi
;
4057 switch (of_reconfig_get_state_change(action
, arg
)) {
4058 case OF_RECONFIG_CHANGE_ADD
:
4059 ctlr
= of_find_spi_controller_by_node(rd
->dn
->parent
);
4061 return NOTIFY_OK
; /* not for us */
4063 if (of_node_test_and_set_flag(rd
->dn
, OF_POPULATED
)) {
4064 put_device(&ctlr
->dev
);
4068 spi
= of_register_spi_device(ctlr
, rd
->dn
);
4069 put_device(&ctlr
->dev
);
4072 pr_err("%s: failed to create for '%pOF'\n",
4074 of_node_clear_flag(rd
->dn
, OF_POPULATED
);
4075 return notifier_from_errno(PTR_ERR(spi
));
4079 case OF_RECONFIG_CHANGE_REMOVE
:
4080 /* already depopulated? */
4081 if (!of_node_check_flag(rd
->dn
, OF_POPULATED
))
4084 /* find our device by node */
4085 spi
= of_find_spi_device_by_node(rd
->dn
);
4087 return NOTIFY_OK
; /* no? not meant for us */
4089 /* unregister takes one ref away */
4090 spi_unregister_device(spi
);
4092 /* and put the reference of the find */
4093 put_device(&spi
->dev
);
4100 static struct notifier_block spi_of_notifier
= {
4101 .notifier_call
= of_spi_notify
,
4103 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4104 extern struct notifier_block spi_of_notifier
;
4105 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4107 #if IS_ENABLED(CONFIG_ACPI)
4108 static int spi_acpi_controller_match(struct device
*dev
, const void *data
)
4110 return ACPI_COMPANION(dev
->parent
) == data
;
4113 static struct spi_controller
*acpi_spi_find_controller_by_adev(struct acpi_device
*adev
)
4117 dev
= class_find_device(&spi_master_class
, NULL
, adev
,
4118 spi_acpi_controller_match
);
4119 if (!dev
&& IS_ENABLED(CONFIG_SPI_SLAVE
))
4120 dev
= class_find_device(&spi_slave_class
, NULL
, adev
,
4121 spi_acpi_controller_match
);
4125 return container_of(dev
, struct spi_controller
, dev
);
4128 static struct spi_device
*acpi_spi_find_device_by_adev(struct acpi_device
*adev
)
4132 dev
= bus_find_device_by_acpi_dev(&spi_bus_type
, adev
);
4133 return to_spi_device(dev
);
4136 static int acpi_spi_notify(struct notifier_block
*nb
, unsigned long value
,
4139 struct acpi_device
*adev
= arg
;
4140 struct spi_controller
*ctlr
;
4141 struct spi_device
*spi
;
4144 case ACPI_RECONFIG_DEVICE_ADD
:
4145 ctlr
= acpi_spi_find_controller_by_adev(adev
->parent
);
4149 acpi_register_spi_device(ctlr
, adev
);
4150 put_device(&ctlr
->dev
);
4152 case ACPI_RECONFIG_DEVICE_REMOVE
:
4153 if (!acpi_device_enumerated(adev
))
4156 spi
= acpi_spi_find_device_by_adev(adev
);
4160 spi_unregister_device(spi
);
4161 put_device(&spi
->dev
);
4168 static struct notifier_block spi_acpi_notifier
= {
4169 .notifier_call
= acpi_spi_notify
,
4172 extern struct notifier_block spi_acpi_notifier
;
4175 static int __init
spi_init(void)
4179 buf
= kmalloc(SPI_BUFSIZ
, GFP_KERNEL
);
4185 status
= bus_register(&spi_bus_type
);
4189 status
= class_register(&spi_master_class
);
4193 if (IS_ENABLED(CONFIG_SPI_SLAVE
)) {
4194 status
= class_register(&spi_slave_class
);
4199 if (IS_ENABLED(CONFIG_OF_DYNAMIC
))
4200 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier
));
4201 if (IS_ENABLED(CONFIG_ACPI
))
4202 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier
));
4207 class_unregister(&spi_master_class
);
4209 bus_unregister(&spi_bus_type
);
4217 /* board_info is normally registered in arch_initcall(),
4218 * but even essential drivers wait till later
4220 * REVISIT only boardinfo really needs static linking. the rest (device and
4221 * driver registration) _could_ be dynamically linked (modular) ... costs
4222 * include needing to have boardinfo data structures be much more public.
4224 postcore_initcall(spi_init
);