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_controller_put(spi
->controller
);
51 kfree(spi
->driver_override
);
56 modalias_show(struct device
*dev
, struct device_attribute
*a
, char *buf
)
58 const struct spi_device
*spi
= to_spi_device(dev
);
61 len
= acpi_device_modalias(dev
, buf
, PAGE_SIZE
- 1);
65 return sprintf(buf
, "%s%s\n", SPI_MODULE_PREFIX
, spi
->modalias
);
67 static DEVICE_ATTR_RO(modalias
);
69 static ssize_t
driver_override_store(struct device
*dev
,
70 struct device_attribute
*a
,
71 const char *buf
, size_t count
)
73 struct spi_device
*spi
= to_spi_device(dev
);
74 const char *end
= memchr(buf
, '\n', count
);
75 const size_t len
= end
? end
- buf
: count
;
76 const char *driver_override
, *old
;
78 /* We need to keep extra room for a newline when displaying value */
79 if (len
>= (PAGE_SIZE
- 1))
82 driver_override
= kstrndup(buf
, len
, GFP_KERNEL
);
87 old
= spi
->driver_override
;
89 spi
->driver_override
= driver_override
;
91 /* Empty string, disable driver override */
92 spi
->driver_override
= NULL
;
93 kfree(driver_override
);
101 static ssize_t
driver_override_show(struct device
*dev
,
102 struct device_attribute
*a
, char *buf
)
104 const struct spi_device
*spi
= to_spi_device(dev
);
108 len
= snprintf(buf
, PAGE_SIZE
, "%s\n", spi
->driver_override
? : "");
112 static DEVICE_ATTR_RW(driver_override
);
114 #define SPI_STATISTICS_ATTRS(field, file) \
115 static ssize_t spi_controller_##field##_show(struct device *dev, \
116 struct device_attribute *attr, \
119 struct spi_controller *ctlr = container_of(dev, \
120 struct spi_controller, dev); \
121 return spi_statistics_##field##_show(&ctlr->statistics, buf); \
123 static struct device_attribute dev_attr_spi_controller_##field = { \
124 .attr = { .name = file, .mode = 0444 }, \
125 .show = spi_controller_##field##_show, \
127 static ssize_t spi_device_##field##_show(struct device *dev, \
128 struct device_attribute *attr, \
131 struct spi_device *spi = to_spi_device(dev); \
132 return spi_statistics_##field##_show(&spi->statistics, buf); \
134 static struct device_attribute dev_attr_spi_device_##field = { \
135 .attr = { .name = file, .mode = 0444 }, \
136 .show = spi_device_##field##_show, \
139 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
140 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
143 unsigned long flags; \
145 spin_lock_irqsave(&stat->lock, flags); \
146 len = sprintf(buf, format_string, stat->field); \
147 spin_unlock_irqrestore(&stat->lock, flags); \
150 SPI_STATISTICS_ATTRS(name, file)
152 #define SPI_STATISTICS_SHOW(field, format_string) \
153 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
154 field, format_string)
156 SPI_STATISTICS_SHOW(messages
, "%lu");
157 SPI_STATISTICS_SHOW(transfers
, "%lu");
158 SPI_STATISTICS_SHOW(errors
, "%lu");
159 SPI_STATISTICS_SHOW(timedout
, "%lu");
161 SPI_STATISTICS_SHOW(spi_sync
, "%lu");
162 SPI_STATISTICS_SHOW(spi_sync_immediate
, "%lu");
163 SPI_STATISTICS_SHOW(spi_async
, "%lu");
165 SPI_STATISTICS_SHOW(bytes
, "%llu");
166 SPI_STATISTICS_SHOW(bytes_rx
, "%llu");
167 SPI_STATISTICS_SHOW(bytes_tx
, "%llu");
169 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
170 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
171 "transfer_bytes_histo_" number, \
172 transfer_bytes_histo[index], "%lu")
173 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
174 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
175 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
176 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
177 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
178 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
179 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
180 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
181 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
182 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
183 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
184 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
185 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
186 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
187 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
188 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
189 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
191 SPI_STATISTICS_SHOW(transfers_split_maxsize
, "%lu");
193 static struct attribute
*spi_dev_attrs
[] = {
194 &dev_attr_modalias
.attr
,
195 &dev_attr_driver_override
.attr
,
199 static const struct attribute_group spi_dev_group
= {
200 .attrs
= spi_dev_attrs
,
203 static struct attribute
*spi_device_statistics_attrs
[] = {
204 &dev_attr_spi_device_messages
.attr
,
205 &dev_attr_spi_device_transfers
.attr
,
206 &dev_attr_spi_device_errors
.attr
,
207 &dev_attr_spi_device_timedout
.attr
,
208 &dev_attr_spi_device_spi_sync
.attr
,
209 &dev_attr_spi_device_spi_sync_immediate
.attr
,
210 &dev_attr_spi_device_spi_async
.attr
,
211 &dev_attr_spi_device_bytes
.attr
,
212 &dev_attr_spi_device_bytes_rx
.attr
,
213 &dev_attr_spi_device_bytes_tx
.attr
,
214 &dev_attr_spi_device_transfer_bytes_histo0
.attr
,
215 &dev_attr_spi_device_transfer_bytes_histo1
.attr
,
216 &dev_attr_spi_device_transfer_bytes_histo2
.attr
,
217 &dev_attr_spi_device_transfer_bytes_histo3
.attr
,
218 &dev_attr_spi_device_transfer_bytes_histo4
.attr
,
219 &dev_attr_spi_device_transfer_bytes_histo5
.attr
,
220 &dev_attr_spi_device_transfer_bytes_histo6
.attr
,
221 &dev_attr_spi_device_transfer_bytes_histo7
.attr
,
222 &dev_attr_spi_device_transfer_bytes_histo8
.attr
,
223 &dev_attr_spi_device_transfer_bytes_histo9
.attr
,
224 &dev_attr_spi_device_transfer_bytes_histo10
.attr
,
225 &dev_attr_spi_device_transfer_bytes_histo11
.attr
,
226 &dev_attr_spi_device_transfer_bytes_histo12
.attr
,
227 &dev_attr_spi_device_transfer_bytes_histo13
.attr
,
228 &dev_attr_spi_device_transfer_bytes_histo14
.attr
,
229 &dev_attr_spi_device_transfer_bytes_histo15
.attr
,
230 &dev_attr_spi_device_transfer_bytes_histo16
.attr
,
231 &dev_attr_spi_device_transfers_split_maxsize
.attr
,
235 static const struct attribute_group spi_device_statistics_group
= {
236 .name
= "statistics",
237 .attrs
= spi_device_statistics_attrs
,
240 static const struct attribute_group
*spi_dev_groups
[] = {
242 &spi_device_statistics_group
,
246 static struct attribute
*spi_controller_statistics_attrs
[] = {
247 &dev_attr_spi_controller_messages
.attr
,
248 &dev_attr_spi_controller_transfers
.attr
,
249 &dev_attr_spi_controller_errors
.attr
,
250 &dev_attr_spi_controller_timedout
.attr
,
251 &dev_attr_spi_controller_spi_sync
.attr
,
252 &dev_attr_spi_controller_spi_sync_immediate
.attr
,
253 &dev_attr_spi_controller_spi_async
.attr
,
254 &dev_attr_spi_controller_bytes
.attr
,
255 &dev_attr_spi_controller_bytes_rx
.attr
,
256 &dev_attr_spi_controller_bytes_tx
.attr
,
257 &dev_attr_spi_controller_transfer_bytes_histo0
.attr
,
258 &dev_attr_spi_controller_transfer_bytes_histo1
.attr
,
259 &dev_attr_spi_controller_transfer_bytes_histo2
.attr
,
260 &dev_attr_spi_controller_transfer_bytes_histo3
.attr
,
261 &dev_attr_spi_controller_transfer_bytes_histo4
.attr
,
262 &dev_attr_spi_controller_transfer_bytes_histo5
.attr
,
263 &dev_attr_spi_controller_transfer_bytes_histo6
.attr
,
264 &dev_attr_spi_controller_transfer_bytes_histo7
.attr
,
265 &dev_attr_spi_controller_transfer_bytes_histo8
.attr
,
266 &dev_attr_spi_controller_transfer_bytes_histo9
.attr
,
267 &dev_attr_spi_controller_transfer_bytes_histo10
.attr
,
268 &dev_attr_spi_controller_transfer_bytes_histo11
.attr
,
269 &dev_attr_spi_controller_transfer_bytes_histo12
.attr
,
270 &dev_attr_spi_controller_transfer_bytes_histo13
.attr
,
271 &dev_attr_spi_controller_transfer_bytes_histo14
.attr
,
272 &dev_attr_spi_controller_transfer_bytes_histo15
.attr
,
273 &dev_attr_spi_controller_transfer_bytes_histo16
.attr
,
274 &dev_attr_spi_controller_transfers_split_maxsize
.attr
,
278 static const struct attribute_group spi_controller_statistics_group
= {
279 .name
= "statistics",
280 .attrs
= spi_controller_statistics_attrs
,
283 static const struct attribute_group
*spi_master_groups
[] = {
284 &spi_controller_statistics_group
,
288 void spi_statistics_add_transfer_stats(struct spi_statistics
*stats
,
289 struct spi_transfer
*xfer
,
290 struct spi_controller
*ctlr
)
293 int l2len
= min(fls(xfer
->len
), SPI_STATISTICS_HISTO_SIZE
) - 1;
298 spin_lock_irqsave(&stats
->lock
, flags
);
301 stats
->transfer_bytes_histo
[l2len
]++;
303 stats
->bytes
+= xfer
->len
;
304 if ((xfer
->tx_buf
) &&
305 (xfer
->tx_buf
!= ctlr
->dummy_tx
))
306 stats
->bytes_tx
+= xfer
->len
;
307 if ((xfer
->rx_buf
) &&
308 (xfer
->rx_buf
!= ctlr
->dummy_rx
))
309 stats
->bytes_rx
+= xfer
->len
;
311 spin_unlock_irqrestore(&stats
->lock
, flags
);
313 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats
);
315 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
316 * and the sysfs version makes coldplug work too.
319 static const struct spi_device_id
*spi_match_id(const struct spi_device_id
*id
,
320 const struct spi_device
*sdev
)
322 while (id
->name
[0]) {
323 if (!strcmp(sdev
->modalias
, id
->name
))
330 const struct spi_device_id
*spi_get_device_id(const struct spi_device
*sdev
)
332 const struct spi_driver
*sdrv
= to_spi_driver(sdev
->dev
.driver
);
334 return spi_match_id(sdrv
->id_table
, sdev
);
336 EXPORT_SYMBOL_GPL(spi_get_device_id
);
338 static int spi_match_device(struct device
*dev
, struct device_driver
*drv
)
340 const struct spi_device
*spi
= to_spi_device(dev
);
341 const struct spi_driver
*sdrv
= to_spi_driver(drv
);
343 /* Check override first, and if set, only use the named driver */
344 if (spi
->driver_override
)
345 return strcmp(spi
->driver_override
, drv
->name
) == 0;
347 /* Attempt an OF style match */
348 if (of_driver_match_device(dev
, drv
))
352 if (acpi_driver_match_device(dev
, drv
))
356 return !!spi_match_id(sdrv
->id_table
, spi
);
358 return strcmp(spi
->modalias
, drv
->name
) == 0;
361 static int spi_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
363 const struct spi_device
*spi
= to_spi_device(dev
);
366 rc
= acpi_device_uevent_modalias(dev
, env
);
370 return add_uevent_var(env
, "MODALIAS=%s%s", SPI_MODULE_PREFIX
, spi
->modalias
);
373 static int spi_probe(struct device
*dev
)
375 const struct spi_driver
*sdrv
= to_spi_driver(dev
->driver
);
376 struct spi_device
*spi
= to_spi_device(dev
);
379 ret
= of_clk_set_defaults(dev
->of_node
, false);
384 spi
->irq
= of_irq_get(dev
->of_node
, 0);
385 if (spi
->irq
== -EPROBE_DEFER
)
386 return -EPROBE_DEFER
;
391 ret
= dev_pm_domain_attach(dev
, true);
396 ret
= sdrv
->probe(spi
);
398 dev_pm_domain_detach(dev
, true);
404 static void spi_remove(struct device
*dev
)
406 const struct spi_driver
*sdrv
= to_spi_driver(dev
->driver
);
411 ret
= sdrv
->remove(to_spi_device(dev
));
414 "Failed to unbind driver (%pe), ignoring\n",
418 dev_pm_domain_detach(dev
, true);
421 static void spi_shutdown(struct device
*dev
)
424 const struct spi_driver
*sdrv
= to_spi_driver(dev
->driver
);
427 sdrv
->shutdown(to_spi_device(dev
));
431 struct bus_type spi_bus_type
= {
433 .dev_groups
= spi_dev_groups
,
434 .match
= spi_match_device
,
435 .uevent
= spi_uevent
,
437 .remove
= spi_remove
,
438 .shutdown
= spi_shutdown
,
440 EXPORT_SYMBOL_GPL(spi_bus_type
);
443 * __spi_register_driver - register a SPI driver
444 * @owner: owner module of the driver to register
445 * @sdrv: the driver to register
448 * Return: zero on success, else a negative error code.
450 int __spi_register_driver(struct module
*owner
, struct spi_driver
*sdrv
)
452 sdrv
->driver
.owner
= owner
;
453 sdrv
->driver
.bus
= &spi_bus_type
;
454 return driver_register(&sdrv
->driver
);
456 EXPORT_SYMBOL_GPL(__spi_register_driver
);
458 /*-------------------------------------------------------------------------*/
460 /* SPI devices should normally not be created by SPI device drivers; that
461 * would make them board-specific. Similarly with SPI controller drivers.
462 * Device registration normally goes into like arch/.../mach.../board-YYY.c
463 * with other readonly (flashable) information about mainboard devices.
467 struct list_head list
;
468 struct spi_board_info board_info
;
471 static LIST_HEAD(board_list
);
472 static LIST_HEAD(spi_controller_list
);
475 * Used to protect add/del operation for board_info list and
476 * spi_controller list, and their matching process
477 * also used to protect object of type struct idr
479 static DEFINE_MUTEX(board_lock
);
482 * spi_alloc_device - Allocate a new SPI device
483 * @ctlr: Controller to which device is connected
486 * Allows a driver to allocate and initialize a spi_device without
487 * registering it immediately. This allows a driver to directly
488 * fill the spi_device with device parameters before calling
489 * spi_add_device() on it.
491 * Caller is responsible to call spi_add_device() on the returned
492 * spi_device structure to add it to the SPI controller. If the caller
493 * needs to discard the spi_device without adding it, then it should
494 * call spi_dev_put() on it.
496 * Return: a pointer to the new device, or NULL.
498 struct spi_device
*spi_alloc_device(struct spi_controller
*ctlr
)
500 struct spi_device
*spi
;
502 if (!spi_controller_get(ctlr
))
505 spi
= kzalloc(sizeof(*spi
), GFP_KERNEL
);
507 spi_controller_put(ctlr
);
511 spi
->master
= spi
->controller
= ctlr
;
512 spi
->dev
.parent
= &ctlr
->dev
;
513 spi
->dev
.bus
= &spi_bus_type
;
514 spi
->dev
.release
= spidev_release
;
515 spi
->cs_gpio
= -ENOENT
;
516 spi
->mode
= ctlr
->buswidth_override_bits
;
518 spin_lock_init(&spi
->statistics
.lock
);
520 device_initialize(&spi
->dev
);
523 EXPORT_SYMBOL_GPL(spi_alloc_device
);
525 static void spi_dev_set_name(struct spi_device
*spi
)
527 struct acpi_device
*adev
= ACPI_COMPANION(&spi
->dev
);
530 dev_set_name(&spi
->dev
, "spi-%s", acpi_dev_name(adev
));
534 dev_set_name(&spi
->dev
, "%s.%u", dev_name(&spi
->controller
->dev
),
538 static int spi_dev_check(struct device
*dev
, void *data
)
540 struct spi_device
*spi
= to_spi_device(dev
);
541 struct spi_device
*new_spi
= data
;
543 if (spi
->controller
== new_spi
->controller
&&
544 spi
->chip_select
== new_spi
->chip_select
)
549 static void spi_cleanup(struct spi_device
*spi
)
551 if (spi
->controller
->cleanup
)
552 spi
->controller
->cleanup(spi
);
555 static int __spi_add_device(struct spi_device
*spi
)
557 struct spi_controller
*ctlr
= spi
->controller
;
558 struct device
*dev
= ctlr
->dev
.parent
;
561 status
= bus_for_each_dev(&spi_bus_type
, NULL
, spi
, spi_dev_check
);
563 dev_err(dev
, "chipselect %d already in use\n",
568 /* Controller may unregister concurrently */
569 if (IS_ENABLED(CONFIG_SPI_DYNAMIC
) &&
570 !device_is_registered(&ctlr
->dev
)) {
574 /* Descriptors take precedence */
576 spi
->cs_gpiod
= ctlr
->cs_gpiods
[spi
->chip_select
];
577 else if (ctlr
->cs_gpios
)
578 spi
->cs_gpio
= ctlr
->cs_gpios
[spi
->chip_select
];
580 /* Drivers may modify this initial i/o setup, but will
581 * normally rely on the device being setup. Devices
582 * using SPI_CS_HIGH can't coexist well otherwise...
584 status
= spi_setup(spi
);
586 dev_err(dev
, "can't setup %s, status %d\n",
587 dev_name(&spi
->dev
), status
);
591 /* Device may be bound to an active driver when this returns */
592 status
= device_add(&spi
->dev
);
594 dev_err(dev
, "can't add %s, status %d\n",
595 dev_name(&spi
->dev
), status
);
598 dev_dbg(dev
, "registered child %s\n", dev_name(&spi
->dev
));
605 * spi_add_device - Add spi_device allocated with spi_alloc_device
606 * @spi: spi_device to register
608 * Companion function to spi_alloc_device. Devices allocated with
609 * spi_alloc_device can be added onto the spi bus with this function.
611 * Return: 0 on success; negative errno on failure
613 int spi_add_device(struct spi_device
*spi
)
615 struct spi_controller
*ctlr
= spi
->controller
;
616 struct device
*dev
= ctlr
->dev
.parent
;
619 /* Chipselects are numbered 0..max; validate. */
620 if (spi
->chip_select
>= ctlr
->num_chipselect
) {
621 dev_err(dev
, "cs%d >= max %d\n", spi
->chip_select
,
622 ctlr
->num_chipselect
);
626 /* Set the bus ID string */
627 spi_dev_set_name(spi
);
629 /* We need to make sure there's no other device with this
630 * chipselect **BEFORE** we call setup(), else we'll trash
631 * its configuration. Lock against concurrent add() calls.
633 mutex_lock(&ctlr
->add_lock
);
634 status
= __spi_add_device(spi
);
635 mutex_unlock(&ctlr
->add_lock
);
638 EXPORT_SYMBOL_GPL(spi_add_device
);
640 static int spi_add_device_locked(struct spi_device
*spi
)
642 struct spi_controller
*ctlr
= spi
->controller
;
643 struct device
*dev
= ctlr
->dev
.parent
;
645 /* Chipselects are numbered 0..max; validate. */
646 if (spi
->chip_select
>= ctlr
->num_chipselect
) {
647 dev_err(dev
, "cs%d >= max %d\n", spi
->chip_select
,
648 ctlr
->num_chipselect
);
652 /* Set the bus ID string */
653 spi_dev_set_name(spi
);
655 WARN_ON(!mutex_is_locked(&ctlr
->add_lock
));
656 return __spi_add_device(spi
);
660 * spi_new_device - instantiate one new SPI device
661 * @ctlr: Controller to which device is connected
662 * @chip: Describes the SPI device
665 * On typical mainboards, this is purely internal; and it's not needed
666 * after board init creates the hard-wired devices. Some development
667 * platforms may not be able to use spi_register_board_info though, and
668 * this is exported so that for example a USB or parport based adapter
669 * driver could add devices (which it would learn about out-of-band).
671 * Return: the new device, or NULL.
673 struct spi_device
*spi_new_device(struct spi_controller
*ctlr
,
674 struct spi_board_info
*chip
)
676 struct spi_device
*proxy
;
679 /* NOTE: caller did any chip->bus_num checks necessary.
681 * Also, unless we change the return value convention to use
682 * error-or-pointer (not NULL-or-pointer), troubleshootability
683 * suggests syslogged diagnostics are best here (ugh).
686 proxy
= spi_alloc_device(ctlr
);
690 WARN_ON(strlen(chip
->modalias
) >= sizeof(proxy
->modalias
));
692 proxy
->chip_select
= chip
->chip_select
;
693 proxy
->max_speed_hz
= chip
->max_speed_hz
;
694 proxy
->mode
= chip
->mode
;
695 proxy
->irq
= chip
->irq
;
696 strlcpy(proxy
->modalias
, chip
->modalias
, sizeof(proxy
->modalias
));
697 proxy
->dev
.platform_data
= (void *) chip
->platform_data
;
698 proxy
->controller_data
= chip
->controller_data
;
699 proxy
->controller_state
= NULL
;
702 status
= device_add_software_node(&proxy
->dev
, chip
->swnode
);
704 dev_err(&ctlr
->dev
, "failed to add software node to '%s': %d\n",
705 chip
->modalias
, status
);
710 status
= spi_add_device(proxy
);
717 device_remove_software_node(&proxy
->dev
);
721 EXPORT_SYMBOL_GPL(spi_new_device
);
724 * spi_unregister_device - unregister a single SPI device
725 * @spi: spi_device to unregister
727 * Start making the passed SPI device vanish. Normally this would be handled
728 * by spi_unregister_controller().
730 void spi_unregister_device(struct spi_device
*spi
)
735 if (spi
->dev
.of_node
) {
736 of_node_clear_flag(spi
->dev
.of_node
, OF_POPULATED
);
737 of_node_put(spi
->dev
.of_node
);
739 if (ACPI_COMPANION(&spi
->dev
))
740 acpi_device_clear_enumerated(ACPI_COMPANION(&spi
->dev
));
741 device_remove_software_node(&spi
->dev
);
742 device_del(&spi
->dev
);
744 put_device(&spi
->dev
);
746 EXPORT_SYMBOL_GPL(spi_unregister_device
);
748 static void spi_match_controller_to_boardinfo(struct spi_controller
*ctlr
,
749 struct spi_board_info
*bi
)
751 struct spi_device
*dev
;
753 if (ctlr
->bus_num
!= bi
->bus_num
)
756 dev
= spi_new_device(ctlr
, bi
);
758 dev_err(ctlr
->dev
.parent
, "can't create new device for %s\n",
763 * spi_register_board_info - register SPI devices for a given board
764 * @info: array of chip descriptors
765 * @n: how many descriptors are provided
768 * Board-specific early init code calls this (probably during arch_initcall)
769 * with segments of the SPI device table. Any device nodes are created later,
770 * after the relevant parent SPI controller (bus_num) is defined. We keep
771 * this table of devices forever, so that reloading a controller driver will
772 * not make Linux forget about these hard-wired devices.
774 * Other code can also call this, e.g. a particular add-on board might provide
775 * SPI devices through its expansion connector, so code initializing that board
776 * would naturally declare its SPI devices.
778 * The board info passed can safely be __initdata ... but be careful of
779 * any embedded pointers (platform_data, etc), they're copied as-is.
781 * Return: zero on success, else a negative error code.
783 int spi_register_board_info(struct spi_board_info
const *info
, unsigned n
)
785 struct boardinfo
*bi
;
791 bi
= kcalloc(n
, sizeof(*bi
), GFP_KERNEL
);
795 for (i
= 0; i
< n
; i
++, bi
++, info
++) {
796 struct spi_controller
*ctlr
;
798 memcpy(&bi
->board_info
, info
, sizeof(*info
));
800 mutex_lock(&board_lock
);
801 list_add_tail(&bi
->list
, &board_list
);
802 list_for_each_entry(ctlr
, &spi_controller_list
, list
)
803 spi_match_controller_to_boardinfo(ctlr
,
805 mutex_unlock(&board_lock
);
811 /*-------------------------------------------------------------------------*/
813 static void spi_set_cs(struct spi_device
*spi
, bool enable
, bool force
)
815 bool activate
= enable
;
818 * Avoid calling into the driver (or doing delays) if the chip select
819 * isn't actually changing from the last time this was called.
821 if (!force
&& (spi
->controller
->last_cs_enable
== enable
) &&
822 (spi
->controller
->last_cs_mode_high
== (spi
->mode
& SPI_CS_HIGH
)))
825 trace_spi_set_cs(spi
, activate
);
827 spi
->controller
->last_cs_enable
= enable
;
828 spi
->controller
->last_cs_mode_high
= spi
->mode
& SPI_CS_HIGH
;
830 if (spi
->cs_gpiod
|| gpio_is_valid(spi
->cs_gpio
) ||
831 !spi
->controller
->set_cs_timing
) {
833 spi_delay_exec(&spi
->cs_setup
, NULL
);
835 spi_delay_exec(&spi
->cs_hold
, NULL
);
838 if (spi
->mode
& SPI_CS_HIGH
)
841 if (spi
->cs_gpiod
|| gpio_is_valid(spi
->cs_gpio
)) {
842 if (!(spi
->mode
& SPI_NO_CS
)) {
845 * Historically ACPI has no means of the GPIO polarity and
846 * thus the SPISerialBus() resource defines it on the per-chip
847 * basis. In order to avoid a chain of negations, the GPIO
848 * polarity is considered being Active High. Even for the cases
849 * when _DSD() is involved (in the updated versions of ACPI)
850 * the GPIO CS polarity must be defined Active High to avoid
851 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
854 if (has_acpi_companion(&spi
->dev
))
855 gpiod_set_value_cansleep(spi
->cs_gpiod
, !enable
);
857 /* Polarity handled by GPIO library */
858 gpiod_set_value_cansleep(spi
->cs_gpiod
, activate
);
861 * invert the enable line, as active low is
864 gpio_set_value_cansleep(spi
->cs_gpio
, !enable
);
867 /* Some SPI masters need both GPIO CS & slave_select */
868 if ((spi
->controller
->flags
& SPI_MASTER_GPIO_SS
) &&
869 spi
->controller
->set_cs
)
870 spi
->controller
->set_cs(spi
, !enable
);
871 } else if (spi
->controller
->set_cs
) {
872 spi
->controller
->set_cs(spi
, !enable
);
875 if (spi
->cs_gpiod
|| gpio_is_valid(spi
->cs_gpio
) ||
876 !spi
->controller
->set_cs_timing
) {
878 spi_delay_exec(&spi
->cs_inactive
, NULL
);
882 #ifdef CONFIG_HAS_DMA
883 int spi_map_buf(struct spi_controller
*ctlr
, struct device
*dev
,
884 struct sg_table
*sgt
, void *buf
, size_t len
,
885 enum dma_data_direction dir
)
887 const bool vmalloced_buf
= is_vmalloc_addr(buf
);
888 unsigned int max_seg_size
= dma_get_max_seg_size(dev
);
889 #ifdef CONFIG_HIGHMEM
890 const bool kmap_buf
= ((unsigned long)buf
>= PKMAP_BASE
&&
891 (unsigned long)buf
< (PKMAP_BASE
+
892 (LAST_PKMAP
* PAGE_SIZE
)));
894 const bool kmap_buf
= false;
898 struct page
*vm_page
;
899 struct scatterlist
*sg
;
904 if (vmalloced_buf
|| kmap_buf
) {
905 desc_len
= min_t(int, max_seg_size
, PAGE_SIZE
);
906 sgs
= DIV_ROUND_UP(len
+ offset_in_page(buf
), desc_len
);
907 } else if (virt_addr_valid(buf
)) {
908 desc_len
= min_t(int, max_seg_size
, ctlr
->max_dma_len
);
909 sgs
= DIV_ROUND_UP(len
, desc_len
);
914 ret
= sg_alloc_table(sgt
, sgs
, GFP_KERNEL
);
919 for (i
= 0; i
< sgs
; i
++) {
921 if (vmalloced_buf
|| kmap_buf
) {
923 * Next scatterlist entry size is the minimum between
924 * the desc_len and the remaining buffer length that
927 min
= min_t(size_t, desc_len
,
929 PAGE_SIZE
- offset_in_page(buf
)));
931 vm_page
= vmalloc_to_page(buf
);
933 vm_page
= kmap_to_page(buf
);
938 sg_set_page(sg
, vm_page
,
939 min
, offset_in_page(buf
));
941 min
= min_t(size_t, len
, desc_len
);
943 sg_set_buf(sg
, sg_buf
, min
);
951 ret
= dma_map_sg(dev
, sgt
->sgl
, sgt
->nents
, dir
);
964 void spi_unmap_buf(struct spi_controller
*ctlr
, struct device
*dev
,
965 struct sg_table
*sgt
, enum dma_data_direction dir
)
967 if (sgt
->orig_nents
) {
968 dma_unmap_sg(dev
, sgt
->sgl
, sgt
->orig_nents
, dir
);
973 static int __spi_map_msg(struct spi_controller
*ctlr
, struct spi_message
*msg
)
975 struct device
*tx_dev
, *rx_dev
;
976 struct spi_transfer
*xfer
;
983 tx_dev
= ctlr
->dma_tx
->device
->dev
;
984 else if (ctlr
->dma_map_dev
)
985 tx_dev
= ctlr
->dma_map_dev
;
987 tx_dev
= ctlr
->dev
.parent
;
990 rx_dev
= ctlr
->dma_rx
->device
->dev
;
991 else if (ctlr
->dma_map_dev
)
992 rx_dev
= ctlr
->dma_map_dev
;
994 rx_dev
= ctlr
->dev
.parent
;
996 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
997 if (!ctlr
->can_dma(ctlr
, msg
->spi
, xfer
))
1000 if (xfer
->tx_buf
!= NULL
) {
1001 ret
= spi_map_buf(ctlr
, tx_dev
, &xfer
->tx_sg
,
1002 (void *)xfer
->tx_buf
, xfer
->len
,
1008 if (xfer
->rx_buf
!= NULL
) {
1009 ret
= spi_map_buf(ctlr
, rx_dev
, &xfer
->rx_sg
,
1010 xfer
->rx_buf
, xfer
->len
,
1013 spi_unmap_buf(ctlr
, tx_dev
, &xfer
->tx_sg
,
1020 ctlr
->cur_msg_mapped
= true;
1025 static int __spi_unmap_msg(struct spi_controller
*ctlr
, struct spi_message
*msg
)
1027 struct spi_transfer
*xfer
;
1028 struct device
*tx_dev
, *rx_dev
;
1030 if (!ctlr
->cur_msg_mapped
|| !ctlr
->can_dma
)
1034 tx_dev
= ctlr
->dma_tx
->device
->dev
;
1036 tx_dev
= ctlr
->dev
.parent
;
1039 rx_dev
= ctlr
->dma_rx
->device
->dev
;
1041 rx_dev
= ctlr
->dev
.parent
;
1043 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
1044 if (!ctlr
->can_dma(ctlr
, msg
->spi
, xfer
))
1047 spi_unmap_buf(ctlr
, rx_dev
, &xfer
->rx_sg
, DMA_FROM_DEVICE
);
1048 spi_unmap_buf(ctlr
, tx_dev
, &xfer
->tx_sg
, DMA_TO_DEVICE
);
1051 ctlr
->cur_msg_mapped
= false;
1055 #else /* !CONFIG_HAS_DMA */
1056 static inline int __spi_map_msg(struct spi_controller
*ctlr
,
1057 struct spi_message
*msg
)
1062 static inline int __spi_unmap_msg(struct spi_controller
*ctlr
,
1063 struct spi_message
*msg
)
1067 #endif /* !CONFIG_HAS_DMA */
1069 static inline int spi_unmap_msg(struct spi_controller
*ctlr
,
1070 struct spi_message
*msg
)
1072 struct spi_transfer
*xfer
;
1074 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
1076 * Restore the original value of tx_buf or rx_buf if they are
1079 if (xfer
->tx_buf
== ctlr
->dummy_tx
)
1080 xfer
->tx_buf
= NULL
;
1081 if (xfer
->rx_buf
== ctlr
->dummy_rx
)
1082 xfer
->rx_buf
= NULL
;
1085 return __spi_unmap_msg(ctlr
, msg
);
1088 static int spi_map_msg(struct spi_controller
*ctlr
, struct spi_message
*msg
)
1090 struct spi_transfer
*xfer
;
1092 unsigned int max_tx
, max_rx
;
1094 if ((ctlr
->flags
& (SPI_CONTROLLER_MUST_RX
| SPI_CONTROLLER_MUST_TX
))
1095 && !(msg
->spi
->mode
& SPI_3WIRE
)) {
1099 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
1100 if ((ctlr
->flags
& SPI_CONTROLLER_MUST_TX
) &&
1102 max_tx
= max(xfer
->len
, max_tx
);
1103 if ((ctlr
->flags
& SPI_CONTROLLER_MUST_RX
) &&
1105 max_rx
= max(xfer
->len
, max_rx
);
1109 tmp
= krealloc(ctlr
->dummy_tx
, max_tx
,
1110 GFP_KERNEL
| GFP_DMA
);
1113 ctlr
->dummy_tx
= tmp
;
1114 memset(tmp
, 0, max_tx
);
1118 tmp
= krealloc(ctlr
->dummy_rx
, max_rx
,
1119 GFP_KERNEL
| GFP_DMA
);
1122 ctlr
->dummy_rx
= tmp
;
1125 if (max_tx
|| max_rx
) {
1126 list_for_each_entry(xfer
, &msg
->transfers
,
1131 xfer
->tx_buf
= ctlr
->dummy_tx
;
1133 xfer
->rx_buf
= ctlr
->dummy_rx
;
1138 return __spi_map_msg(ctlr
, msg
);
1141 static int spi_transfer_wait(struct spi_controller
*ctlr
,
1142 struct spi_message
*msg
,
1143 struct spi_transfer
*xfer
)
1145 struct spi_statistics
*statm
= &ctlr
->statistics
;
1146 struct spi_statistics
*stats
= &msg
->spi
->statistics
;
1147 u32 speed_hz
= xfer
->speed_hz
;
1148 unsigned long long ms
;
1150 if (spi_controller_is_slave(ctlr
)) {
1151 if (wait_for_completion_interruptible(&ctlr
->xfer_completion
)) {
1152 dev_dbg(&msg
->spi
->dev
, "SPI transfer interrupted\n");
1160 * For each byte we wait for 8 cycles of the SPI clock.
1161 * Since speed is defined in Hz and we want milliseconds,
1162 * use respective multiplier, but before the division,
1163 * otherwise we may get 0 for short transfers.
1165 ms
= 8LL * MSEC_PER_SEC
* xfer
->len
;
1166 do_div(ms
, speed_hz
);
1169 * Increase it twice and add 200 ms tolerance, use
1170 * predefined maximum in case of overflow.
1176 ms
= wait_for_completion_timeout(&ctlr
->xfer_completion
,
1177 msecs_to_jiffies(ms
));
1180 SPI_STATISTICS_INCREMENT_FIELD(statm
, timedout
);
1181 SPI_STATISTICS_INCREMENT_FIELD(stats
, timedout
);
1182 dev_err(&msg
->spi
->dev
,
1183 "SPI transfer timed out\n");
1191 static void _spi_transfer_delay_ns(u32 ns
)
1195 if (ns
<= NSEC_PER_USEC
) {
1198 u32 us
= DIV_ROUND_UP(ns
, NSEC_PER_USEC
);
1203 usleep_range(us
, us
+ DIV_ROUND_UP(us
, 10));
1207 int spi_delay_to_ns(struct spi_delay
*_delay
, struct spi_transfer
*xfer
)
1209 u32 delay
= _delay
->value
;
1210 u32 unit
= _delay
->unit
;
1217 case SPI_DELAY_UNIT_USECS
:
1218 delay
*= NSEC_PER_USEC
;
1220 case SPI_DELAY_UNIT_NSECS
:
1221 /* Nothing to do here */
1223 case SPI_DELAY_UNIT_SCK
:
1224 /* clock cycles need to be obtained from spi_transfer */
1228 * If there is unknown effective speed, approximate it
1229 * by underestimating with half of the requested hz.
1231 hz
= xfer
->effective_speed_hz
?: xfer
->speed_hz
/ 2;
1235 /* Convert delay to nanoseconds */
1236 delay
*= DIV_ROUND_UP(NSEC_PER_SEC
, hz
);
1244 EXPORT_SYMBOL_GPL(spi_delay_to_ns
);
1246 int spi_delay_exec(struct spi_delay
*_delay
, struct spi_transfer
*xfer
)
1255 delay
= spi_delay_to_ns(_delay
, xfer
);
1259 _spi_transfer_delay_ns(delay
);
1263 EXPORT_SYMBOL_GPL(spi_delay_exec
);
1265 static void _spi_transfer_cs_change_delay(struct spi_message
*msg
,
1266 struct spi_transfer
*xfer
)
1268 u32 default_delay_ns
= 10 * NSEC_PER_USEC
;
1269 u32 delay
= xfer
->cs_change_delay
.value
;
1270 u32 unit
= xfer
->cs_change_delay
.unit
;
1273 /* return early on "fast" mode - for everything but USECS */
1275 if (unit
== SPI_DELAY_UNIT_USECS
)
1276 _spi_transfer_delay_ns(default_delay_ns
);
1280 ret
= spi_delay_exec(&xfer
->cs_change_delay
, xfer
);
1282 dev_err_once(&msg
->spi
->dev
,
1283 "Use of unsupported delay unit %i, using default of %luus\n",
1284 unit
, default_delay_ns
/ NSEC_PER_USEC
);
1285 _spi_transfer_delay_ns(default_delay_ns
);
1290 * spi_transfer_one_message - Default implementation of transfer_one_message()
1292 * This is a standard implementation of transfer_one_message() for
1293 * drivers which implement a transfer_one() operation. It provides
1294 * standard handling of delays and chip select management.
1296 static int spi_transfer_one_message(struct spi_controller
*ctlr
,
1297 struct spi_message
*msg
)
1299 struct spi_transfer
*xfer
;
1300 bool keep_cs
= false;
1302 struct spi_statistics
*statm
= &ctlr
->statistics
;
1303 struct spi_statistics
*stats
= &msg
->spi
->statistics
;
1305 spi_set_cs(msg
->spi
, true, false);
1307 SPI_STATISTICS_INCREMENT_FIELD(statm
, messages
);
1308 SPI_STATISTICS_INCREMENT_FIELD(stats
, messages
);
1310 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
1311 trace_spi_transfer_start(msg
, xfer
);
1313 spi_statistics_add_transfer_stats(statm
, xfer
, ctlr
);
1314 spi_statistics_add_transfer_stats(stats
, xfer
, ctlr
);
1316 if (!ctlr
->ptp_sts_supported
) {
1317 xfer
->ptp_sts_word_pre
= 0;
1318 ptp_read_system_prets(xfer
->ptp_sts
);
1321 if ((xfer
->tx_buf
|| xfer
->rx_buf
) && xfer
->len
) {
1322 reinit_completion(&ctlr
->xfer_completion
);
1325 ret
= ctlr
->transfer_one(ctlr
, msg
->spi
, xfer
);
1327 if (ctlr
->cur_msg_mapped
&&
1328 (xfer
->error
& SPI_TRANS_FAIL_NO_START
)) {
1329 __spi_unmap_msg(ctlr
, msg
);
1330 ctlr
->fallback
= true;
1331 xfer
->error
&= ~SPI_TRANS_FAIL_NO_START
;
1335 SPI_STATISTICS_INCREMENT_FIELD(statm
,
1337 SPI_STATISTICS_INCREMENT_FIELD(stats
,
1339 dev_err(&msg
->spi
->dev
,
1340 "SPI transfer failed: %d\n", ret
);
1345 ret
= spi_transfer_wait(ctlr
, msg
, xfer
);
1351 dev_err(&msg
->spi
->dev
,
1352 "Bufferless transfer has length %u\n",
1356 if (!ctlr
->ptp_sts_supported
) {
1357 ptp_read_system_postts(xfer
->ptp_sts
);
1358 xfer
->ptp_sts_word_post
= xfer
->len
;
1361 trace_spi_transfer_stop(msg
, xfer
);
1363 if (msg
->status
!= -EINPROGRESS
)
1366 spi_transfer_delay_exec(xfer
);
1368 if (xfer
->cs_change
) {
1369 if (list_is_last(&xfer
->transfer_list
,
1373 spi_set_cs(msg
->spi
, false, false);
1374 _spi_transfer_cs_change_delay(msg
, xfer
);
1375 spi_set_cs(msg
->spi
, true, false);
1379 msg
->actual_length
+= xfer
->len
;
1383 if (ret
!= 0 || !keep_cs
)
1384 spi_set_cs(msg
->spi
, false, false);
1386 if (msg
->status
== -EINPROGRESS
)
1389 if (msg
->status
&& ctlr
->handle_err
)
1390 ctlr
->handle_err(ctlr
, msg
);
1392 spi_finalize_current_message(ctlr
);
1398 * spi_finalize_current_transfer - report completion of a transfer
1399 * @ctlr: the controller reporting completion
1401 * Called by SPI drivers using the core transfer_one_message()
1402 * implementation to notify it that the current interrupt driven
1403 * transfer has finished and the next one may be scheduled.
1405 void spi_finalize_current_transfer(struct spi_controller
*ctlr
)
1407 complete(&ctlr
->xfer_completion
);
1409 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer
);
1411 static void spi_idle_runtime_pm(struct spi_controller
*ctlr
)
1413 if (ctlr
->auto_runtime_pm
) {
1414 pm_runtime_mark_last_busy(ctlr
->dev
.parent
);
1415 pm_runtime_put_autosuspend(ctlr
->dev
.parent
);
1420 * __spi_pump_messages - function which processes spi message queue
1421 * @ctlr: controller to process queue for
1422 * @in_kthread: true if we are in the context of the message pump thread
1424 * This function checks if there is any spi message in the queue that
1425 * needs processing and if so call out to the driver to initialize hardware
1426 * and transfer each message.
1428 * Note that it is called both from the kthread itself and also from
1429 * inside spi_sync(); the queue extraction handling at the top of the
1430 * function should deal with this safely.
1432 static void __spi_pump_messages(struct spi_controller
*ctlr
, bool in_kthread
)
1434 struct spi_transfer
*xfer
;
1435 struct spi_message
*msg
;
1436 bool was_busy
= false;
1437 unsigned long flags
;
1441 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1443 /* Make sure we are not already running a message */
1444 if (ctlr
->cur_msg
) {
1445 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1449 /* If another context is idling the device then defer */
1451 kthread_queue_work(ctlr
->kworker
, &ctlr
->pump_messages
);
1452 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1456 /* Check if the queue is idle */
1457 if (list_empty(&ctlr
->queue
) || !ctlr
->running
) {
1459 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1463 /* Defer any non-atomic teardown to the thread */
1465 if (!ctlr
->dummy_rx
&& !ctlr
->dummy_tx
&&
1466 !ctlr
->unprepare_transfer_hardware
) {
1467 spi_idle_runtime_pm(ctlr
);
1469 trace_spi_controller_idle(ctlr
);
1471 kthread_queue_work(ctlr
->kworker
,
1472 &ctlr
->pump_messages
);
1474 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1479 ctlr
->idling
= true;
1480 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1482 kfree(ctlr
->dummy_rx
);
1483 ctlr
->dummy_rx
= NULL
;
1484 kfree(ctlr
->dummy_tx
);
1485 ctlr
->dummy_tx
= NULL
;
1486 if (ctlr
->unprepare_transfer_hardware
&&
1487 ctlr
->unprepare_transfer_hardware(ctlr
))
1489 "failed to unprepare transfer hardware\n");
1490 spi_idle_runtime_pm(ctlr
);
1491 trace_spi_controller_idle(ctlr
);
1493 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1494 ctlr
->idling
= false;
1495 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1499 /* Extract head of queue */
1500 msg
= list_first_entry(&ctlr
->queue
, struct spi_message
, queue
);
1501 ctlr
->cur_msg
= msg
;
1503 list_del_init(&msg
->queue
);
1508 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1510 mutex_lock(&ctlr
->io_mutex
);
1512 if (!was_busy
&& ctlr
->auto_runtime_pm
) {
1513 ret
= pm_runtime_get_sync(ctlr
->dev
.parent
);
1515 pm_runtime_put_noidle(ctlr
->dev
.parent
);
1516 dev_err(&ctlr
->dev
, "Failed to power device: %d\n",
1518 mutex_unlock(&ctlr
->io_mutex
);
1524 trace_spi_controller_busy(ctlr
);
1526 if (!was_busy
&& ctlr
->prepare_transfer_hardware
) {
1527 ret
= ctlr
->prepare_transfer_hardware(ctlr
);
1530 "failed to prepare transfer hardware: %d\n",
1533 if (ctlr
->auto_runtime_pm
)
1534 pm_runtime_put(ctlr
->dev
.parent
);
1537 spi_finalize_current_message(ctlr
);
1539 mutex_unlock(&ctlr
->io_mutex
);
1544 trace_spi_message_start(msg
);
1546 if (ctlr
->prepare_message
) {
1547 ret
= ctlr
->prepare_message(ctlr
, msg
);
1549 dev_err(&ctlr
->dev
, "failed to prepare message: %d\n",
1552 spi_finalize_current_message(ctlr
);
1555 ctlr
->cur_msg_prepared
= true;
1558 ret
= spi_map_msg(ctlr
, msg
);
1561 spi_finalize_current_message(ctlr
);
1565 if (!ctlr
->ptp_sts_supported
&& !ctlr
->transfer_one
) {
1566 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
1567 xfer
->ptp_sts_word_pre
= 0;
1568 ptp_read_system_prets(xfer
->ptp_sts
);
1572 ret
= ctlr
->transfer_one_message(ctlr
, msg
);
1575 "failed to transfer one message from queue\n");
1580 mutex_unlock(&ctlr
->io_mutex
);
1582 /* Prod the scheduler in case transfer_one() was busy waiting */
1588 * spi_pump_messages - kthread work function which processes spi message queue
1589 * @work: pointer to kthread work struct contained in the controller struct
1591 static void spi_pump_messages(struct kthread_work
*work
)
1593 struct spi_controller
*ctlr
=
1594 container_of(work
, struct spi_controller
, pump_messages
);
1596 __spi_pump_messages(ctlr
, true);
1600 * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
1601 * TX timestamp for the requested byte from the SPI
1602 * transfer. The frequency with which this function
1603 * must be called (once per word, once for the whole
1604 * transfer, once per batch of words etc) is arbitrary
1605 * as long as the @tx buffer offset is greater than or
1606 * equal to the requested byte at the time of the
1607 * call. The timestamp is only taken once, at the
1608 * first such call. It is assumed that the driver
1609 * advances its @tx buffer pointer monotonically.
1610 * @ctlr: Pointer to the spi_controller structure of the driver
1611 * @xfer: Pointer to the transfer being timestamped
1612 * @progress: How many words (not bytes) have been transferred so far
1613 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1614 * transfer, for less jitter in time measurement. Only compatible
1615 * with PIO drivers. If true, must follow up with
1616 * spi_take_timestamp_post or otherwise system will crash.
1617 * WARNING: for fully predictable results, the CPU frequency must
1618 * also be under control (governor).
1620 void spi_take_timestamp_pre(struct spi_controller
*ctlr
,
1621 struct spi_transfer
*xfer
,
1622 size_t progress
, bool irqs_off
)
1627 if (xfer
->timestamped
)
1630 if (progress
> xfer
->ptp_sts_word_pre
)
1633 /* Capture the resolution of the timestamp */
1634 xfer
->ptp_sts_word_pre
= progress
;
1637 local_irq_save(ctlr
->irq_flags
);
1641 ptp_read_system_prets(xfer
->ptp_sts
);
1643 EXPORT_SYMBOL_GPL(spi_take_timestamp_pre
);
1646 * spi_take_timestamp_post - helper for drivers to collect the end of the
1647 * TX timestamp for the requested byte from the SPI
1648 * transfer. Can be called with an arbitrary
1649 * frequency: only the first call where @tx exceeds
1650 * or is equal to the requested word will be
1652 * @ctlr: Pointer to the spi_controller structure of the driver
1653 * @xfer: Pointer to the transfer being timestamped
1654 * @progress: How many words (not bytes) have been transferred so far
1655 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1657 void spi_take_timestamp_post(struct spi_controller
*ctlr
,
1658 struct spi_transfer
*xfer
,
1659 size_t progress
, bool irqs_off
)
1664 if (xfer
->timestamped
)
1667 if (progress
< xfer
->ptp_sts_word_post
)
1670 ptp_read_system_postts(xfer
->ptp_sts
);
1673 local_irq_restore(ctlr
->irq_flags
);
1677 /* Capture the resolution of the timestamp */
1678 xfer
->ptp_sts_word_post
= progress
;
1680 xfer
->timestamped
= true;
1682 EXPORT_SYMBOL_GPL(spi_take_timestamp_post
);
1685 * spi_set_thread_rt - set the controller to pump at realtime priority
1686 * @ctlr: controller to boost priority of
1688 * This can be called because the controller requested realtime priority
1689 * (by setting the ->rt value before calling spi_register_controller()) or
1690 * because a device on the bus said that its transfers needed realtime
1693 * NOTE: at the moment if any device on a bus says it needs realtime then
1694 * the thread will be at realtime priority for all transfers on that
1695 * controller. If this eventually becomes a problem we may see if we can
1696 * find a way to boost the priority only temporarily during relevant
1699 static void spi_set_thread_rt(struct spi_controller
*ctlr
)
1701 dev_info(&ctlr
->dev
,
1702 "will run message pump with realtime priority\n");
1703 sched_set_fifo(ctlr
->kworker
->task
);
1706 static int spi_init_queue(struct spi_controller
*ctlr
)
1708 ctlr
->running
= false;
1711 ctlr
->kworker
= kthread_create_worker(0, dev_name(&ctlr
->dev
));
1712 if (IS_ERR(ctlr
->kworker
)) {
1713 dev_err(&ctlr
->dev
, "failed to create message pump kworker\n");
1714 return PTR_ERR(ctlr
->kworker
);
1717 kthread_init_work(&ctlr
->pump_messages
, spi_pump_messages
);
1720 * Controller config will indicate if this controller should run the
1721 * message pump with high (realtime) priority to reduce the transfer
1722 * latency on the bus by minimising the delay between a transfer
1723 * request and the scheduling of the message pump thread. Without this
1724 * setting the message pump thread will remain at default priority.
1727 spi_set_thread_rt(ctlr
);
1733 * spi_get_next_queued_message() - called by driver to check for queued
1735 * @ctlr: the controller to check for queued messages
1737 * If there are more messages in the queue, the next message is returned from
1740 * Return: the next message in the queue, else NULL if the queue is empty.
1742 struct spi_message
*spi_get_next_queued_message(struct spi_controller
*ctlr
)
1744 struct spi_message
*next
;
1745 unsigned long flags
;
1747 /* get a pointer to the next message, if any */
1748 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1749 next
= list_first_entry_or_null(&ctlr
->queue
, struct spi_message
,
1751 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1755 EXPORT_SYMBOL_GPL(spi_get_next_queued_message
);
1758 * spi_finalize_current_message() - the current message is complete
1759 * @ctlr: the controller to return the message to
1761 * Called by the driver to notify the core that the message in the front of the
1762 * queue is complete and can be removed from the queue.
1764 void spi_finalize_current_message(struct spi_controller
*ctlr
)
1766 struct spi_transfer
*xfer
;
1767 struct spi_message
*mesg
;
1768 unsigned long flags
;
1771 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1772 mesg
= ctlr
->cur_msg
;
1773 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1775 if (!ctlr
->ptp_sts_supported
&& !ctlr
->transfer_one
) {
1776 list_for_each_entry(xfer
, &mesg
->transfers
, transfer_list
) {
1777 ptp_read_system_postts(xfer
->ptp_sts
);
1778 xfer
->ptp_sts_word_post
= xfer
->len
;
1782 if (unlikely(ctlr
->ptp_sts_supported
))
1783 list_for_each_entry(xfer
, &mesg
->transfers
, transfer_list
)
1784 WARN_ON_ONCE(xfer
->ptp_sts
&& !xfer
->timestamped
);
1786 spi_unmap_msg(ctlr
, mesg
);
1788 /* In the prepare_messages callback the spi bus has the opportunity to
1789 * split a transfer to smaller chunks.
1790 * Release splited transfers here since spi_map_msg is done on the
1791 * splited transfers.
1793 spi_res_release(ctlr
, mesg
);
1795 if (ctlr
->cur_msg_prepared
&& ctlr
->unprepare_message
) {
1796 ret
= ctlr
->unprepare_message(ctlr
, mesg
);
1798 dev_err(&ctlr
->dev
, "failed to unprepare message: %d\n",
1803 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1804 ctlr
->cur_msg
= NULL
;
1805 ctlr
->cur_msg_prepared
= false;
1806 ctlr
->fallback
= false;
1807 kthread_queue_work(ctlr
->kworker
, &ctlr
->pump_messages
);
1808 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1810 trace_spi_message_done(mesg
);
1814 mesg
->complete(mesg
->context
);
1816 EXPORT_SYMBOL_GPL(spi_finalize_current_message
);
1818 static int spi_start_queue(struct spi_controller
*ctlr
)
1820 unsigned long flags
;
1822 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1824 if (ctlr
->running
|| ctlr
->busy
) {
1825 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1829 ctlr
->running
= true;
1830 ctlr
->cur_msg
= NULL
;
1831 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1833 kthread_queue_work(ctlr
->kworker
, &ctlr
->pump_messages
);
1838 static int spi_stop_queue(struct spi_controller
*ctlr
)
1840 unsigned long flags
;
1841 unsigned limit
= 500;
1844 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1847 * This is a bit lame, but is optimized for the common execution path.
1848 * A wait_queue on the ctlr->busy could be used, but then the common
1849 * execution path (pump_messages) would be required to call wake_up or
1850 * friends on every SPI message. Do this instead.
1852 while ((!list_empty(&ctlr
->queue
) || ctlr
->busy
) && limit
--) {
1853 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1854 usleep_range(10000, 11000);
1855 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1858 if (!list_empty(&ctlr
->queue
) || ctlr
->busy
)
1861 ctlr
->running
= false;
1863 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1866 dev_warn(&ctlr
->dev
, "could not stop message queue\n");
1872 static int spi_destroy_queue(struct spi_controller
*ctlr
)
1876 ret
= spi_stop_queue(ctlr
);
1879 * kthread_flush_worker will block until all work is done.
1880 * If the reason that stop_queue timed out is that the work will never
1881 * finish, then it does no good to call flush/stop thread, so
1885 dev_err(&ctlr
->dev
, "problem destroying queue\n");
1889 kthread_destroy_worker(ctlr
->kworker
);
1894 static int __spi_queued_transfer(struct spi_device
*spi
,
1895 struct spi_message
*msg
,
1898 struct spi_controller
*ctlr
= spi
->controller
;
1899 unsigned long flags
;
1901 spin_lock_irqsave(&ctlr
->queue_lock
, flags
);
1903 if (!ctlr
->running
) {
1904 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1907 msg
->actual_length
= 0;
1908 msg
->status
= -EINPROGRESS
;
1910 list_add_tail(&msg
->queue
, &ctlr
->queue
);
1911 if (!ctlr
->busy
&& need_pump
)
1912 kthread_queue_work(ctlr
->kworker
, &ctlr
->pump_messages
);
1914 spin_unlock_irqrestore(&ctlr
->queue_lock
, flags
);
1919 * spi_queued_transfer - transfer function for queued transfers
1920 * @spi: spi device which is requesting transfer
1921 * @msg: spi message which is to handled is queued to driver queue
1923 * Return: zero on success, else a negative error code.
1925 static int spi_queued_transfer(struct spi_device
*spi
, struct spi_message
*msg
)
1927 return __spi_queued_transfer(spi
, msg
, true);
1930 static int spi_controller_initialize_queue(struct spi_controller
*ctlr
)
1934 ctlr
->transfer
= spi_queued_transfer
;
1935 if (!ctlr
->transfer_one_message
)
1936 ctlr
->transfer_one_message
= spi_transfer_one_message
;
1938 /* Initialize and start queue */
1939 ret
= spi_init_queue(ctlr
);
1941 dev_err(&ctlr
->dev
, "problem initializing queue\n");
1942 goto err_init_queue
;
1944 ctlr
->queued
= true;
1945 ret
= spi_start_queue(ctlr
);
1947 dev_err(&ctlr
->dev
, "problem starting queue\n");
1948 goto err_start_queue
;
1954 spi_destroy_queue(ctlr
);
1960 * spi_flush_queue - Send all pending messages in the queue from the callers'
1962 * @ctlr: controller to process queue for
1964 * This should be used when one wants to ensure all pending messages have been
1965 * sent before doing something. Is used by the spi-mem code to make sure SPI
1966 * memory operations do not preempt regular SPI transfers that have been queued
1967 * before the spi-mem operation.
1969 void spi_flush_queue(struct spi_controller
*ctlr
)
1971 if (ctlr
->transfer
== spi_queued_transfer
)
1972 __spi_pump_messages(ctlr
, false);
1975 /*-------------------------------------------------------------------------*/
1977 #if defined(CONFIG_OF)
1978 static int of_spi_parse_dt(struct spi_controller
*ctlr
, struct spi_device
*spi
,
1979 struct device_node
*nc
)
1984 /* Mode (clock phase/polarity/etc.) */
1985 if (of_property_read_bool(nc
, "spi-cpha"))
1986 spi
->mode
|= SPI_CPHA
;
1987 if (of_property_read_bool(nc
, "spi-cpol"))
1988 spi
->mode
|= SPI_CPOL
;
1989 if (of_property_read_bool(nc
, "spi-3wire"))
1990 spi
->mode
|= SPI_3WIRE
;
1991 if (of_property_read_bool(nc
, "spi-lsb-first"))
1992 spi
->mode
|= SPI_LSB_FIRST
;
1993 if (of_property_read_bool(nc
, "spi-cs-high"))
1994 spi
->mode
|= SPI_CS_HIGH
;
1996 /* Device DUAL/QUAD mode */
1997 if (!of_property_read_u32(nc
, "spi-tx-bus-width", &value
)) {
2000 spi
->mode
|= SPI_NO_TX
;
2005 spi
->mode
|= SPI_TX_DUAL
;
2008 spi
->mode
|= SPI_TX_QUAD
;
2011 spi
->mode
|= SPI_TX_OCTAL
;
2014 dev_warn(&ctlr
->dev
,
2015 "spi-tx-bus-width %d not supported\n",
2021 if (!of_property_read_u32(nc
, "spi-rx-bus-width", &value
)) {
2024 spi
->mode
|= SPI_NO_RX
;
2029 spi
->mode
|= SPI_RX_DUAL
;
2032 spi
->mode
|= SPI_RX_QUAD
;
2035 spi
->mode
|= SPI_RX_OCTAL
;
2038 dev_warn(&ctlr
->dev
,
2039 "spi-rx-bus-width %d not supported\n",
2045 if (spi_controller_is_slave(ctlr
)) {
2046 if (!of_node_name_eq(nc
, "slave")) {
2047 dev_err(&ctlr
->dev
, "%pOF is not called 'slave'\n",
2054 /* Device address */
2055 rc
= of_property_read_u32(nc
, "reg", &value
);
2057 dev_err(&ctlr
->dev
, "%pOF has no valid 'reg' property (%d)\n",
2061 spi
->chip_select
= value
;
2064 if (!of_property_read_u32(nc
, "spi-max-frequency", &value
))
2065 spi
->max_speed_hz
= value
;
2070 static struct spi_device
*
2071 of_register_spi_device(struct spi_controller
*ctlr
, struct device_node
*nc
)
2073 struct spi_device
*spi
;
2076 /* Alloc an spi_device */
2077 spi
= spi_alloc_device(ctlr
);
2079 dev_err(&ctlr
->dev
, "spi_device alloc error for %pOF\n", nc
);
2084 /* Select device driver */
2085 rc
= of_modalias_node(nc
, spi
->modalias
,
2086 sizeof(spi
->modalias
));
2088 dev_err(&ctlr
->dev
, "cannot find modalias for %pOF\n", nc
);
2092 rc
= of_spi_parse_dt(ctlr
, spi
, nc
);
2096 /* Store a pointer to the node in the device structure */
2098 spi
->dev
.of_node
= nc
;
2099 spi
->dev
.fwnode
= of_fwnode_handle(nc
);
2101 /* Register the new device */
2102 rc
= spi_add_device(spi
);
2104 dev_err(&ctlr
->dev
, "spi_device register error %pOF\n", nc
);
2105 goto err_of_node_put
;
2118 * of_register_spi_devices() - Register child devices onto the SPI bus
2119 * @ctlr: Pointer to spi_controller device
2121 * Registers an spi_device for each child node of controller node which
2122 * represents a valid SPI slave.
2124 static void of_register_spi_devices(struct spi_controller
*ctlr
)
2126 struct spi_device
*spi
;
2127 struct device_node
*nc
;
2129 if (!ctlr
->dev
.of_node
)
2132 for_each_available_child_of_node(ctlr
->dev
.of_node
, nc
) {
2133 if (of_node_test_and_set_flag(nc
, OF_POPULATED
))
2135 spi
= of_register_spi_device(ctlr
, nc
);
2137 dev_warn(&ctlr
->dev
,
2138 "Failed to create SPI device for %pOF\n", nc
);
2139 of_node_clear_flag(nc
, OF_POPULATED
);
2144 static void of_register_spi_devices(struct spi_controller
*ctlr
) { }
2148 * spi_new_ancillary_device() - Register ancillary SPI device
2149 * @spi: Pointer to the main SPI device registering the ancillary device
2150 * @chip_select: Chip Select of the ancillary device
2152 * Register an ancillary SPI device; for example some chips have a chip-select
2153 * for normal device usage and another one for setup/firmware upload.
2155 * This may only be called from main SPI device's probe routine.
2157 * Return: 0 on success; negative errno on failure
2159 struct spi_device
*spi_new_ancillary_device(struct spi_device
*spi
,
2162 struct spi_device
*ancillary
;
2165 /* Alloc an spi_device */
2166 ancillary
= spi_alloc_device(spi
->controller
);
2172 strlcpy(ancillary
->modalias
, "dummy", sizeof(ancillary
->modalias
));
2174 /* Use provided chip-select for ancillary device */
2175 ancillary
->chip_select
= chip_select
;
2177 /* Take over SPI mode/speed from SPI main device */
2178 ancillary
->max_speed_hz
= spi
->max_speed_hz
;
2179 ancillary
->mode
= spi
->mode
;
2181 /* Register the new device */
2182 rc
= spi_add_device_locked(ancillary
);
2184 dev_err(&spi
->dev
, "failed to register ancillary device\n");
2191 spi_dev_put(ancillary
);
2194 EXPORT_SYMBOL_GPL(spi_new_ancillary_device
);
2197 struct acpi_spi_lookup
{
2198 struct spi_controller
*ctlr
;
2206 static void acpi_spi_parse_apple_properties(struct acpi_device
*dev
,
2207 struct acpi_spi_lookup
*lookup
)
2209 const union acpi_object
*obj
;
2211 if (!x86_apple_machine
)
2214 if (!acpi_dev_get_property(dev
, "spiSclkPeriod", ACPI_TYPE_BUFFER
, &obj
)
2215 && obj
->buffer
.length
>= 4)
2216 lookup
->max_speed_hz
= NSEC_PER_SEC
/ *(u32
*)obj
->buffer
.pointer
;
2218 if (!acpi_dev_get_property(dev
, "spiWordSize", ACPI_TYPE_BUFFER
, &obj
)
2219 && obj
->buffer
.length
== 8)
2220 lookup
->bits_per_word
= *(u64
*)obj
->buffer
.pointer
;
2222 if (!acpi_dev_get_property(dev
, "spiBitOrder", ACPI_TYPE_BUFFER
, &obj
)
2223 && obj
->buffer
.length
== 8 && !*(u64
*)obj
->buffer
.pointer
)
2224 lookup
->mode
|= SPI_LSB_FIRST
;
2226 if (!acpi_dev_get_property(dev
, "spiSPO", ACPI_TYPE_BUFFER
, &obj
)
2227 && obj
->buffer
.length
== 8 && *(u64
*)obj
->buffer
.pointer
)
2228 lookup
->mode
|= SPI_CPOL
;
2230 if (!acpi_dev_get_property(dev
, "spiSPH", ACPI_TYPE_BUFFER
, &obj
)
2231 && obj
->buffer
.length
== 8 && *(u64
*)obj
->buffer
.pointer
)
2232 lookup
->mode
|= SPI_CPHA
;
2235 static int acpi_spi_add_resource(struct acpi_resource
*ares
, void *data
)
2237 struct acpi_spi_lookup
*lookup
= data
;
2238 struct spi_controller
*ctlr
= lookup
->ctlr
;
2240 if (ares
->type
== ACPI_RESOURCE_TYPE_SERIAL_BUS
) {
2241 struct acpi_resource_spi_serialbus
*sb
;
2242 acpi_handle parent_handle
;
2245 sb
= &ares
->data
.spi_serial_bus
;
2246 if (sb
->type
== ACPI_RESOURCE_SERIAL_TYPE_SPI
) {
2248 status
= acpi_get_handle(NULL
,
2249 sb
->resource_source
.string_ptr
,
2252 if (ACPI_FAILURE(status
) ||
2253 ACPI_HANDLE(ctlr
->dev
.parent
) != parent_handle
)
2257 * ACPI DeviceSelection numbering is handled by the
2258 * host controller driver in Windows and can vary
2259 * from driver to driver. In Linux we always expect
2260 * 0 .. max - 1 so we need to ask the driver to
2261 * translate between the two schemes.
2263 if (ctlr
->fw_translate_cs
) {
2264 int cs
= ctlr
->fw_translate_cs(ctlr
,
2265 sb
->device_selection
);
2268 lookup
->chip_select
= cs
;
2270 lookup
->chip_select
= sb
->device_selection
;
2273 lookup
->max_speed_hz
= sb
->connection_speed
;
2274 lookup
->bits_per_word
= sb
->data_bit_length
;
2276 if (sb
->clock_phase
== ACPI_SPI_SECOND_PHASE
)
2277 lookup
->mode
|= SPI_CPHA
;
2278 if (sb
->clock_polarity
== ACPI_SPI_START_HIGH
)
2279 lookup
->mode
|= SPI_CPOL
;
2280 if (sb
->device_polarity
== ACPI_SPI_ACTIVE_HIGH
)
2281 lookup
->mode
|= SPI_CS_HIGH
;
2283 } else if (lookup
->irq
< 0) {
2286 if (acpi_dev_resource_interrupt(ares
, 0, &r
))
2287 lookup
->irq
= r
.start
;
2290 /* Always tell the ACPI core to skip this resource */
2294 static acpi_status
acpi_register_spi_device(struct spi_controller
*ctlr
,
2295 struct acpi_device
*adev
)
2297 acpi_handle parent_handle
= NULL
;
2298 struct list_head resource_list
;
2299 struct acpi_spi_lookup lookup
= {};
2300 struct spi_device
*spi
;
2303 if (acpi_bus_get_status(adev
) || !adev
->status
.present
||
2304 acpi_device_enumerated(adev
))
2310 INIT_LIST_HEAD(&resource_list
);
2311 ret
= acpi_dev_get_resources(adev
, &resource_list
,
2312 acpi_spi_add_resource
, &lookup
);
2313 acpi_dev_free_resource_list(&resource_list
);
2316 /* found SPI in _CRS but it points to another controller */
2319 if (!lookup
.max_speed_hz
&&
2320 ACPI_SUCCESS(acpi_get_parent(adev
->handle
, &parent_handle
)) &&
2321 ACPI_HANDLE(ctlr
->dev
.parent
) == parent_handle
) {
2322 /* Apple does not use _CRS but nested devices for SPI slaves */
2323 acpi_spi_parse_apple_properties(adev
, &lookup
);
2326 if (!lookup
.max_speed_hz
)
2329 spi
= spi_alloc_device(ctlr
);
2331 dev_err(&ctlr
->dev
, "failed to allocate SPI device for %s\n",
2332 dev_name(&adev
->dev
));
2333 return AE_NO_MEMORY
;
2337 ACPI_COMPANION_SET(&spi
->dev
, adev
);
2338 spi
->max_speed_hz
= lookup
.max_speed_hz
;
2339 spi
->mode
|= lookup
.mode
;
2340 spi
->irq
= lookup
.irq
;
2341 spi
->bits_per_word
= lookup
.bits_per_word
;
2342 spi
->chip_select
= lookup
.chip_select
;
2344 acpi_set_modalias(adev
, acpi_device_hid(adev
), spi
->modalias
,
2345 sizeof(spi
->modalias
));
2348 spi
->irq
= acpi_dev_gpio_irq_get(adev
, 0);
2350 acpi_device_set_enumerated(adev
);
2352 adev
->power
.flags
.ignore_parent
= true;
2353 if (spi_add_device(spi
)) {
2354 adev
->power
.flags
.ignore_parent
= false;
2355 dev_err(&ctlr
->dev
, "failed to add SPI device %s from ACPI\n",
2356 dev_name(&adev
->dev
));
2363 static acpi_status
acpi_spi_add_device(acpi_handle handle
, u32 level
,
2364 void *data
, void **return_value
)
2366 struct spi_controller
*ctlr
= data
;
2367 struct acpi_device
*adev
;
2369 if (acpi_bus_get_device(handle
, &adev
))
2372 return acpi_register_spi_device(ctlr
, adev
);
2375 #define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2377 static void acpi_register_spi_devices(struct spi_controller
*ctlr
)
2382 handle
= ACPI_HANDLE(ctlr
->dev
.parent
);
2386 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
2387 SPI_ACPI_ENUMERATE_MAX_DEPTH
,
2388 acpi_spi_add_device
, NULL
, ctlr
, NULL
);
2389 if (ACPI_FAILURE(status
))
2390 dev_warn(&ctlr
->dev
, "failed to enumerate SPI slaves\n");
2393 static inline void acpi_register_spi_devices(struct spi_controller
*ctlr
) {}
2394 #endif /* CONFIG_ACPI */
2396 static void spi_controller_release(struct device
*dev
)
2398 struct spi_controller
*ctlr
;
2400 ctlr
= container_of(dev
, struct spi_controller
, dev
);
2404 static struct class spi_master_class
= {
2405 .name
= "spi_master",
2406 .owner
= THIS_MODULE
,
2407 .dev_release
= spi_controller_release
,
2408 .dev_groups
= spi_master_groups
,
2411 #ifdef CONFIG_SPI_SLAVE
2413 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2415 * @spi: device used for the current transfer
2417 int spi_slave_abort(struct spi_device
*spi
)
2419 struct spi_controller
*ctlr
= spi
->controller
;
2421 if (spi_controller_is_slave(ctlr
) && ctlr
->slave_abort
)
2422 return ctlr
->slave_abort(ctlr
);
2426 EXPORT_SYMBOL_GPL(spi_slave_abort
);
2428 static int match_true(struct device
*dev
, void *data
)
2433 static ssize_t
slave_show(struct device
*dev
, struct device_attribute
*attr
,
2436 struct spi_controller
*ctlr
= container_of(dev
, struct spi_controller
,
2438 struct device
*child
;
2440 child
= device_find_child(&ctlr
->dev
, NULL
, match_true
);
2441 return sprintf(buf
, "%s\n",
2442 child
? to_spi_device(child
)->modalias
: NULL
);
2445 static ssize_t
slave_store(struct device
*dev
, struct device_attribute
*attr
,
2446 const char *buf
, size_t count
)
2448 struct spi_controller
*ctlr
= container_of(dev
, struct spi_controller
,
2450 struct spi_device
*spi
;
2451 struct device
*child
;
2455 rc
= sscanf(buf
, "%31s", name
);
2456 if (rc
!= 1 || !name
[0])
2459 child
= device_find_child(&ctlr
->dev
, NULL
, match_true
);
2461 /* Remove registered slave */
2462 device_unregister(child
);
2466 if (strcmp(name
, "(null)")) {
2467 /* Register new slave */
2468 spi
= spi_alloc_device(ctlr
);
2472 strlcpy(spi
->modalias
, name
, sizeof(spi
->modalias
));
2474 rc
= spi_add_device(spi
);
2484 static DEVICE_ATTR_RW(slave
);
2486 static struct attribute
*spi_slave_attrs
[] = {
2487 &dev_attr_slave
.attr
,
2491 static const struct attribute_group spi_slave_group
= {
2492 .attrs
= spi_slave_attrs
,
2495 static const struct attribute_group
*spi_slave_groups
[] = {
2496 &spi_controller_statistics_group
,
2501 static struct class spi_slave_class
= {
2502 .name
= "spi_slave",
2503 .owner
= THIS_MODULE
,
2504 .dev_release
= spi_controller_release
,
2505 .dev_groups
= spi_slave_groups
,
2508 extern struct class spi_slave_class
; /* dummy */
2512 * __spi_alloc_controller - allocate an SPI master or slave controller
2513 * @dev: the controller, possibly using the platform_bus
2514 * @size: how much zeroed driver-private data to allocate; the pointer to this
2515 * memory is in the driver_data field of the returned device, accessible
2516 * with spi_controller_get_devdata(); the memory is cacheline aligned;
2517 * drivers granting DMA access to portions of their private data need to
2518 * round up @size using ALIGN(size, dma_get_cache_alignment()).
2519 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2520 * slave (true) controller
2521 * Context: can sleep
2523 * This call is used only by SPI controller drivers, which are the
2524 * only ones directly touching chip registers. It's how they allocate
2525 * an spi_controller structure, prior to calling spi_register_controller().
2527 * This must be called from context that can sleep.
2529 * The caller is responsible for assigning the bus number and initializing the
2530 * controller's methods before calling spi_register_controller(); and (after
2531 * errors adding the device) calling spi_controller_put() to prevent a memory
2534 * Return: the SPI controller structure on success, else NULL.
2536 struct spi_controller
*__spi_alloc_controller(struct device
*dev
,
2537 unsigned int size
, bool slave
)
2539 struct spi_controller
*ctlr
;
2540 size_t ctlr_size
= ALIGN(sizeof(*ctlr
), dma_get_cache_alignment());
2545 ctlr
= kzalloc(size
+ ctlr_size
, GFP_KERNEL
);
2549 device_initialize(&ctlr
->dev
);
2550 INIT_LIST_HEAD(&ctlr
->queue
);
2551 spin_lock_init(&ctlr
->queue_lock
);
2552 spin_lock_init(&ctlr
->bus_lock_spinlock
);
2553 mutex_init(&ctlr
->bus_lock_mutex
);
2554 mutex_init(&ctlr
->io_mutex
);
2555 mutex_init(&ctlr
->add_lock
);
2557 ctlr
->num_chipselect
= 1;
2558 ctlr
->slave
= slave
;
2559 if (IS_ENABLED(CONFIG_SPI_SLAVE
) && slave
)
2560 ctlr
->dev
.class = &spi_slave_class
;
2562 ctlr
->dev
.class = &spi_master_class
;
2563 ctlr
->dev
.parent
= dev
;
2564 pm_suspend_ignore_children(&ctlr
->dev
, true);
2565 spi_controller_set_devdata(ctlr
, (void *)ctlr
+ ctlr_size
);
2569 EXPORT_SYMBOL_GPL(__spi_alloc_controller
);
2571 static void devm_spi_release_controller(struct device
*dev
, void *ctlr
)
2573 spi_controller_put(*(struct spi_controller
**)ctlr
);
2577 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
2578 * @dev: physical device of SPI controller
2579 * @size: how much zeroed driver-private data to allocate
2580 * @slave: whether to allocate an SPI master (false) or SPI slave (true)
2581 * Context: can sleep
2583 * Allocate an SPI controller and automatically release a reference on it
2584 * when @dev is unbound from its driver. Drivers are thus relieved from
2585 * having to call spi_controller_put().
2587 * The arguments to this function are identical to __spi_alloc_controller().
2589 * Return: the SPI controller structure on success, else NULL.
2591 struct spi_controller
*__devm_spi_alloc_controller(struct device
*dev
,
2595 struct spi_controller
**ptr
, *ctlr
;
2597 ptr
= devres_alloc(devm_spi_release_controller
, sizeof(*ptr
),
2602 ctlr
= __spi_alloc_controller(dev
, size
, slave
);
2604 ctlr
->devm_allocated
= true;
2606 devres_add(dev
, ptr
);
2613 EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller
);
2616 static int of_spi_get_gpio_numbers(struct spi_controller
*ctlr
)
2619 struct device_node
*np
= ctlr
->dev
.of_node
;
2624 nb
= of_gpio_named_count(np
, "cs-gpios");
2625 ctlr
->num_chipselect
= max_t(int, nb
, ctlr
->num_chipselect
);
2627 /* Return error only for an incorrectly formed cs-gpios property */
2628 if (nb
== 0 || nb
== -ENOENT
)
2633 cs
= devm_kcalloc(&ctlr
->dev
, ctlr
->num_chipselect
, sizeof(int),
2635 ctlr
->cs_gpios
= cs
;
2637 if (!ctlr
->cs_gpios
)
2640 for (i
= 0; i
< ctlr
->num_chipselect
; i
++)
2643 for (i
= 0; i
< nb
; i
++)
2644 cs
[i
] = of_get_named_gpio(np
, "cs-gpios", i
);
2649 static int of_spi_get_gpio_numbers(struct spi_controller
*ctlr
)
2656 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2657 * @ctlr: The SPI master to grab GPIO descriptors for
2659 static int spi_get_gpio_descs(struct spi_controller
*ctlr
)
2662 struct gpio_desc
**cs
;
2663 struct device
*dev
= &ctlr
->dev
;
2664 unsigned long native_cs_mask
= 0;
2665 unsigned int num_cs_gpios
= 0;
2667 nb
= gpiod_count(dev
, "cs");
2669 /* No GPIOs at all is fine, else return the error */
2675 ctlr
->num_chipselect
= max_t(int, nb
, ctlr
->num_chipselect
);
2677 cs
= devm_kcalloc(dev
, ctlr
->num_chipselect
, sizeof(*cs
),
2681 ctlr
->cs_gpiods
= cs
;
2683 for (i
= 0; i
< nb
; i
++) {
2685 * Most chipselects are active low, the inverted
2686 * semantics are handled by special quirks in gpiolib,
2687 * so initializing them GPIOD_OUT_LOW here means
2688 * "unasserted", in most cases this will drive the physical
2691 cs
[i
] = devm_gpiod_get_index_optional(dev
, "cs", i
,
2694 return PTR_ERR(cs
[i
]);
2698 * If we find a CS GPIO, name it after the device and
2703 gpioname
= devm_kasprintf(dev
, GFP_KERNEL
, "%s CS%d",
2707 gpiod_set_consumer_name(cs
[i
], gpioname
);
2712 if (ctlr
->max_native_cs
&& i
>= ctlr
->max_native_cs
) {
2713 dev_err(dev
, "Invalid native chip select %d\n", i
);
2716 native_cs_mask
|= BIT(i
);
2719 ctlr
->unused_native_cs
= ffs(~native_cs_mask
) - 1;
2721 if ((ctlr
->flags
& SPI_MASTER_GPIO_SS
) && num_cs_gpios
&&
2722 ctlr
->max_native_cs
&& ctlr
->unused_native_cs
>= ctlr
->max_native_cs
) {
2723 dev_err(dev
, "No unused native chip select available\n");
2730 static int spi_controller_check_ops(struct spi_controller
*ctlr
)
2733 * The controller may implement only the high-level SPI-memory like
2734 * operations if it does not support regular SPI transfers, and this is
2736 * If ->mem_ops is NULL, we request that at least one of the
2737 * ->transfer_xxx() method be implemented.
2739 if (ctlr
->mem_ops
) {
2740 if (!ctlr
->mem_ops
->exec_op
)
2742 } else if (!ctlr
->transfer
&& !ctlr
->transfer_one
&&
2743 !ctlr
->transfer_one_message
) {
2751 * spi_register_controller - register SPI master or slave controller
2752 * @ctlr: initialized master, originally from spi_alloc_master() or
2754 * Context: can sleep
2756 * SPI controllers connect to their drivers using some non-SPI bus,
2757 * such as the platform bus. The final stage of probe() in that code
2758 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2760 * SPI controllers use board specific (often SOC specific) bus numbers,
2761 * and board-specific addressing for SPI devices combines those numbers
2762 * with chip select numbers. Since SPI does not directly support dynamic
2763 * device identification, boards need configuration tables telling which
2764 * chip is at which address.
2766 * This must be called from context that can sleep. It returns zero on
2767 * success, else a negative error code (dropping the controller's refcount).
2768 * After a successful return, the caller is responsible for calling
2769 * spi_unregister_controller().
2771 * Return: zero on success, else a negative error code.
2773 int spi_register_controller(struct spi_controller
*ctlr
)
2775 struct device
*dev
= ctlr
->dev
.parent
;
2776 struct boardinfo
*bi
;
2778 int id
, first_dynamic
;
2784 * Make sure all necessary hooks are implemented before registering
2785 * the SPI controller.
2787 status
= spi_controller_check_ops(ctlr
);
2791 if (ctlr
->bus_num
>= 0) {
2792 /* devices with a fixed bus num must check-in with the num */
2793 mutex_lock(&board_lock
);
2794 id
= idr_alloc(&spi_master_idr
, ctlr
, ctlr
->bus_num
,
2795 ctlr
->bus_num
+ 1, GFP_KERNEL
);
2796 mutex_unlock(&board_lock
);
2797 if (WARN(id
< 0, "couldn't get idr"))
2798 return id
== -ENOSPC
? -EBUSY
: id
;
2800 } else if (ctlr
->dev
.of_node
) {
2801 /* allocate dynamic bus number using Linux idr */
2802 id
= of_alias_get_id(ctlr
->dev
.of_node
, "spi");
2805 mutex_lock(&board_lock
);
2806 id
= idr_alloc(&spi_master_idr
, ctlr
, ctlr
->bus_num
,
2807 ctlr
->bus_num
+ 1, GFP_KERNEL
);
2808 mutex_unlock(&board_lock
);
2809 if (WARN(id
< 0, "couldn't get idr"))
2810 return id
== -ENOSPC
? -EBUSY
: id
;
2813 if (ctlr
->bus_num
< 0) {
2814 first_dynamic
= of_alias_get_highest_id("spi");
2815 if (first_dynamic
< 0)
2820 mutex_lock(&board_lock
);
2821 id
= idr_alloc(&spi_master_idr
, ctlr
, first_dynamic
,
2823 mutex_unlock(&board_lock
);
2824 if (WARN(id
< 0, "couldn't get idr"))
2828 ctlr
->bus_lock_flag
= 0;
2829 init_completion(&ctlr
->xfer_completion
);
2830 if (!ctlr
->max_dma_len
)
2831 ctlr
->max_dma_len
= INT_MAX
;
2833 /* register the device, then userspace will see it.
2834 * registration fails if the bus ID is in use.
2836 dev_set_name(&ctlr
->dev
, "spi%u", ctlr
->bus_num
);
2838 if (!spi_controller_is_slave(ctlr
)) {
2839 if (ctlr
->use_gpio_descriptors
) {
2840 status
= spi_get_gpio_descs(ctlr
);
2844 * A controller using GPIO descriptors always
2845 * supports SPI_CS_HIGH if need be.
2847 ctlr
->mode_bits
|= SPI_CS_HIGH
;
2849 /* Legacy code path for GPIOs from DT */
2850 status
= of_spi_get_gpio_numbers(ctlr
);
2857 * Even if it's just one always-selected device, there must
2858 * be at least one chipselect.
2860 if (!ctlr
->num_chipselect
) {
2865 status
= device_add(&ctlr
->dev
);
2868 dev_dbg(dev
, "registered %s %s\n",
2869 spi_controller_is_slave(ctlr
) ? "slave" : "master",
2870 dev_name(&ctlr
->dev
));
2873 * If we're using a queued driver, start the queue. Note that we don't
2874 * need the queueing logic if the driver is only supporting high-level
2875 * memory operations.
2877 if (ctlr
->transfer
) {
2878 dev_info(dev
, "controller is unqueued, this is deprecated\n");
2879 } else if (ctlr
->transfer_one
|| ctlr
->transfer_one_message
) {
2880 status
= spi_controller_initialize_queue(ctlr
);
2882 device_del(&ctlr
->dev
);
2886 /* add statistics */
2887 spin_lock_init(&ctlr
->statistics
.lock
);
2889 mutex_lock(&board_lock
);
2890 list_add_tail(&ctlr
->list
, &spi_controller_list
);
2891 list_for_each_entry(bi
, &board_list
, list
)
2892 spi_match_controller_to_boardinfo(ctlr
, &bi
->board_info
);
2893 mutex_unlock(&board_lock
);
2895 /* Register devices from the device tree and ACPI */
2896 of_register_spi_devices(ctlr
);
2897 acpi_register_spi_devices(ctlr
);
2901 mutex_lock(&board_lock
);
2902 idr_remove(&spi_master_idr
, ctlr
->bus_num
);
2903 mutex_unlock(&board_lock
);
2906 EXPORT_SYMBOL_GPL(spi_register_controller
);
2908 static void devm_spi_unregister(void *ctlr
)
2910 spi_unregister_controller(ctlr
);
2914 * devm_spi_register_controller - register managed SPI master or slave
2916 * @dev: device managing SPI controller
2917 * @ctlr: initialized controller, originally from spi_alloc_master() or
2919 * Context: can sleep
2921 * Register a SPI device as with spi_register_controller() which will
2922 * automatically be unregistered and freed.
2924 * Return: zero on success, else a negative error code.
2926 int devm_spi_register_controller(struct device
*dev
,
2927 struct spi_controller
*ctlr
)
2931 ret
= spi_register_controller(ctlr
);
2935 return devm_add_action_or_reset(dev
, devm_spi_unregister
, ctlr
);
2937 EXPORT_SYMBOL_GPL(devm_spi_register_controller
);
2939 static int __unregister(struct device
*dev
, void *null
)
2941 spi_unregister_device(to_spi_device(dev
));
2946 * spi_unregister_controller - unregister SPI master or slave controller
2947 * @ctlr: the controller being unregistered
2948 * Context: can sleep
2950 * This call is used only by SPI controller drivers, which are the
2951 * only ones directly touching chip registers.
2953 * This must be called from context that can sleep.
2955 * Note that this function also drops a reference to the controller.
2957 void spi_unregister_controller(struct spi_controller
*ctlr
)
2959 struct spi_controller
*found
;
2960 int id
= ctlr
->bus_num
;
2962 /* Prevent addition of new devices, unregister existing ones */
2963 if (IS_ENABLED(CONFIG_SPI_DYNAMIC
))
2964 mutex_lock(&ctlr
->add_lock
);
2966 device_for_each_child(&ctlr
->dev
, NULL
, __unregister
);
2968 /* First make sure that this controller was ever added */
2969 mutex_lock(&board_lock
);
2970 found
= idr_find(&spi_master_idr
, id
);
2971 mutex_unlock(&board_lock
);
2973 if (spi_destroy_queue(ctlr
))
2974 dev_err(&ctlr
->dev
, "queue remove failed\n");
2976 mutex_lock(&board_lock
);
2977 list_del(&ctlr
->list
);
2978 mutex_unlock(&board_lock
);
2980 device_del(&ctlr
->dev
);
2982 /* Release the last reference on the controller if its driver
2983 * has not yet been converted to devm_spi_alloc_master/slave().
2985 if (!ctlr
->devm_allocated
)
2986 put_device(&ctlr
->dev
);
2989 mutex_lock(&board_lock
);
2991 idr_remove(&spi_master_idr
, id
);
2992 mutex_unlock(&board_lock
);
2994 if (IS_ENABLED(CONFIG_SPI_DYNAMIC
))
2995 mutex_unlock(&ctlr
->add_lock
);
2997 EXPORT_SYMBOL_GPL(spi_unregister_controller
);
2999 int spi_controller_suspend(struct spi_controller
*ctlr
)
3003 /* Basically no-ops for non-queued controllers */
3007 ret
= spi_stop_queue(ctlr
);
3009 dev_err(&ctlr
->dev
, "queue stop failed\n");
3013 EXPORT_SYMBOL_GPL(spi_controller_suspend
);
3015 int spi_controller_resume(struct spi_controller
*ctlr
)
3022 ret
= spi_start_queue(ctlr
);
3024 dev_err(&ctlr
->dev
, "queue restart failed\n");
3028 EXPORT_SYMBOL_GPL(spi_controller_resume
);
3030 static int __spi_controller_match(struct device
*dev
, const void *data
)
3032 struct spi_controller
*ctlr
;
3033 const u16
*bus_num
= data
;
3035 ctlr
= container_of(dev
, struct spi_controller
, dev
);
3036 return ctlr
->bus_num
== *bus_num
;
3040 * spi_busnum_to_master - look up master associated with bus_num
3041 * @bus_num: the master's bus number
3042 * Context: can sleep
3044 * This call may be used with devices that are registered after
3045 * arch init time. It returns a refcounted pointer to the relevant
3046 * spi_controller (which the caller must release), or NULL if there is
3047 * no such master registered.
3049 * Return: the SPI master structure on success, else NULL.
3051 struct spi_controller
*spi_busnum_to_master(u16 bus_num
)
3054 struct spi_controller
*ctlr
= NULL
;
3056 dev
= class_find_device(&spi_master_class
, NULL
, &bus_num
,
3057 __spi_controller_match
);
3059 ctlr
= container_of(dev
, struct spi_controller
, dev
);
3060 /* reference got in class_find_device */
3063 EXPORT_SYMBOL_GPL(spi_busnum_to_master
);
3065 /*-------------------------------------------------------------------------*/
3067 /* Core methods for SPI resource management */
3070 * spi_res_alloc - allocate a spi resource that is life-cycle managed
3071 * during the processing of a spi_message while using
3073 * @spi: the spi device for which we allocate memory
3074 * @release: the release code to execute for this resource
3075 * @size: size to alloc and return
3076 * @gfp: GFP allocation flags
3078 * Return: the pointer to the allocated data
3080 * This may get enhanced in the future to allocate from a memory pool
3081 * of the @spi_device or @spi_controller to avoid repeated allocations.
3083 void *spi_res_alloc(struct spi_device
*spi
,
3084 spi_res_release_t release
,
3085 size_t size
, gfp_t gfp
)
3087 struct spi_res
*sres
;
3089 sres
= kzalloc(sizeof(*sres
) + size
, gfp
);
3093 INIT_LIST_HEAD(&sres
->entry
);
3094 sres
->release
= release
;
3098 EXPORT_SYMBOL_GPL(spi_res_alloc
);
3101 * spi_res_free - free an spi resource
3102 * @res: pointer to the custom data of a resource
3105 void spi_res_free(void *res
)
3107 struct spi_res
*sres
= container_of(res
, struct spi_res
, data
);
3112 WARN_ON(!list_empty(&sres
->entry
));
3115 EXPORT_SYMBOL_GPL(spi_res_free
);
3118 * spi_res_add - add a spi_res to the spi_message
3119 * @message: the spi message
3120 * @res: the spi_resource
3122 void spi_res_add(struct spi_message
*message
, void *res
)
3124 struct spi_res
*sres
= container_of(res
, struct spi_res
, data
);
3126 WARN_ON(!list_empty(&sres
->entry
));
3127 list_add_tail(&sres
->entry
, &message
->resources
);
3129 EXPORT_SYMBOL_GPL(spi_res_add
);
3132 * spi_res_release - release all spi resources for this message
3133 * @ctlr: the @spi_controller
3134 * @message: the @spi_message
3136 void spi_res_release(struct spi_controller
*ctlr
, struct spi_message
*message
)
3138 struct spi_res
*res
, *tmp
;
3140 list_for_each_entry_safe_reverse(res
, tmp
, &message
->resources
, entry
) {
3142 res
->release(ctlr
, message
, res
->data
);
3144 list_del(&res
->entry
);
3149 EXPORT_SYMBOL_GPL(spi_res_release
);
3151 /*-------------------------------------------------------------------------*/
3153 /* Core methods for spi_message alterations */
3155 static void __spi_replace_transfers_release(struct spi_controller
*ctlr
,
3156 struct spi_message
*msg
,
3159 struct spi_replaced_transfers
*rxfer
= res
;
3162 /* call extra callback if requested */
3164 rxfer
->release(ctlr
, msg
, res
);
3166 /* insert replaced transfers back into the message */
3167 list_splice(&rxfer
->replaced_transfers
, rxfer
->replaced_after
);
3169 /* remove the formerly inserted entries */
3170 for (i
= 0; i
< rxfer
->inserted
; i
++)
3171 list_del(&rxfer
->inserted_transfers
[i
].transfer_list
);
3175 * spi_replace_transfers - replace transfers with several transfers
3176 * and register change with spi_message.resources
3177 * @msg: the spi_message we work upon
3178 * @xfer_first: the first spi_transfer we want to replace
3179 * @remove: number of transfers to remove
3180 * @insert: the number of transfers we want to insert instead
3181 * @release: extra release code necessary in some circumstances
3182 * @extradatasize: extra data to allocate (with alignment guarantees
3183 * of struct @spi_transfer)
3186 * Returns: pointer to @spi_replaced_transfers,
3187 * PTR_ERR(...) in case of errors.
3189 struct spi_replaced_transfers
*spi_replace_transfers(
3190 struct spi_message
*msg
,
3191 struct spi_transfer
*xfer_first
,
3194 spi_replaced_release_t release
,
3195 size_t extradatasize
,
3198 struct spi_replaced_transfers
*rxfer
;
3199 struct spi_transfer
*xfer
;
3202 /* allocate the structure using spi_res */
3203 rxfer
= spi_res_alloc(msg
->spi
, __spi_replace_transfers_release
,
3204 struct_size(rxfer
, inserted_transfers
, insert
)
3208 return ERR_PTR(-ENOMEM
);
3210 /* the release code to invoke before running the generic release */
3211 rxfer
->release
= release
;
3213 /* assign extradata */
3216 &rxfer
->inserted_transfers
[insert
];
3218 /* init the replaced_transfers list */
3219 INIT_LIST_HEAD(&rxfer
->replaced_transfers
);
3221 /* assign the list_entry after which we should reinsert
3222 * the @replaced_transfers - it may be spi_message.messages!
3224 rxfer
->replaced_after
= xfer_first
->transfer_list
.prev
;
3226 /* remove the requested number of transfers */
3227 for (i
= 0; i
< remove
; i
++) {
3228 /* if the entry after replaced_after it is msg->transfers
3229 * then we have been requested to remove more transfers
3230 * than are in the list
3232 if (rxfer
->replaced_after
->next
== &msg
->transfers
) {
3233 dev_err(&msg
->spi
->dev
,
3234 "requested to remove more spi_transfers than are available\n");
3235 /* insert replaced transfers back into the message */
3236 list_splice(&rxfer
->replaced_transfers
,
3237 rxfer
->replaced_after
);
3239 /* free the spi_replace_transfer structure */
3240 spi_res_free(rxfer
);
3242 /* and return with an error */
3243 return ERR_PTR(-EINVAL
);
3246 /* remove the entry after replaced_after from list of
3247 * transfers and add it to list of replaced_transfers
3249 list_move_tail(rxfer
->replaced_after
->next
,
3250 &rxfer
->replaced_transfers
);
3253 /* create copy of the given xfer with identical settings
3254 * based on the first transfer to get removed
3256 for (i
= 0; i
< insert
; i
++) {
3257 /* we need to run in reverse order */
3258 xfer
= &rxfer
->inserted_transfers
[insert
- 1 - i
];
3260 /* copy all spi_transfer data */
3261 memcpy(xfer
, xfer_first
, sizeof(*xfer
));
3264 list_add(&xfer
->transfer_list
, rxfer
->replaced_after
);
3266 /* clear cs_change and delay for all but the last */
3268 xfer
->cs_change
= false;
3269 xfer
->delay
.value
= 0;
3273 /* set up inserted */
3274 rxfer
->inserted
= insert
;
3276 /* and register it with spi_res/spi_message */
3277 spi_res_add(msg
, rxfer
);
3281 EXPORT_SYMBOL_GPL(spi_replace_transfers
);
3283 static int __spi_split_transfer_maxsize(struct spi_controller
*ctlr
,
3284 struct spi_message
*msg
,
3285 struct spi_transfer
**xferp
,
3289 struct spi_transfer
*xfer
= *xferp
, *xfers
;
3290 struct spi_replaced_transfers
*srt
;
3294 /* calculate how many we have to replace */
3295 count
= DIV_ROUND_UP(xfer
->len
, maxsize
);
3297 /* create replacement */
3298 srt
= spi_replace_transfers(msg
, xfer
, 1, count
, NULL
, 0, gfp
);
3300 return PTR_ERR(srt
);
3301 xfers
= srt
->inserted_transfers
;
3303 /* now handle each of those newly inserted spi_transfers
3304 * note that the replacements spi_transfers all are preset
3305 * to the same values as *xferp, so tx_buf, rx_buf and len
3306 * are all identical (as well as most others)
3307 * so we just have to fix up len and the pointers.
3309 * this also includes support for the depreciated
3310 * spi_message.is_dma_mapped interface
3313 /* the first transfer just needs the length modified, so we
3314 * run it outside the loop
3316 xfers
[0].len
= min_t(size_t, maxsize
, xfer
[0].len
);
3318 /* all the others need rx_buf/tx_buf also set */
3319 for (i
= 1, offset
= maxsize
; i
< count
; offset
+= maxsize
, i
++) {
3320 /* update rx_buf, tx_buf and dma */
3321 if (xfers
[i
].rx_buf
)
3322 xfers
[i
].rx_buf
+= offset
;
3323 if (xfers
[i
].rx_dma
)
3324 xfers
[i
].rx_dma
+= offset
;
3325 if (xfers
[i
].tx_buf
)
3326 xfers
[i
].tx_buf
+= offset
;
3327 if (xfers
[i
].tx_dma
)
3328 xfers
[i
].tx_dma
+= offset
;
3331 xfers
[i
].len
= min(maxsize
, xfers
[i
].len
- offset
);
3334 /* we set up xferp to the last entry we have inserted,
3335 * so that we skip those already split transfers
3337 *xferp
= &xfers
[count
- 1];
3339 /* increment statistics counters */
3340 SPI_STATISTICS_INCREMENT_FIELD(&ctlr
->statistics
,
3341 transfers_split_maxsize
);
3342 SPI_STATISTICS_INCREMENT_FIELD(&msg
->spi
->statistics
,
3343 transfers_split_maxsize
);
3349 * spi_split_transfers_maxsize - split spi transfers into multiple transfers
3350 * when an individual transfer exceeds a
3352 * @ctlr: the @spi_controller for this transfer
3353 * @msg: the @spi_message to transform
3354 * @maxsize: the maximum when to apply this
3355 * @gfp: GFP allocation flags
3357 * Return: status of transformation
3359 int spi_split_transfers_maxsize(struct spi_controller
*ctlr
,
3360 struct spi_message
*msg
,
3364 struct spi_transfer
*xfer
;
3367 /* iterate over the transfer_list,
3368 * but note that xfer is advanced to the last transfer inserted
3369 * to avoid checking sizes again unnecessarily (also xfer does
3370 * potentiall belong to a different list by the time the
3371 * replacement has happened
3373 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
3374 if (xfer
->len
> maxsize
) {
3375 ret
= __spi_split_transfer_maxsize(ctlr
, msg
, &xfer
,
3384 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize
);
3386 /*-------------------------------------------------------------------------*/
3388 /* Core methods for SPI controller protocol drivers. Some of the
3389 * other core methods are currently defined as inline functions.
3392 static int __spi_validate_bits_per_word(struct spi_controller
*ctlr
,
3395 if (ctlr
->bits_per_word_mask
) {
3396 /* Only 32 bits fit in the mask */
3397 if (bits_per_word
> 32)
3399 if (!(ctlr
->bits_per_word_mask
& SPI_BPW_MASK(bits_per_word
)))
3407 * spi_setup - setup SPI mode and clock rate
3408 * @spi: the device whose settings are being modified
3409 * Context: can sleep, and no requests are queued to the device
3411 * SPI protocol drivers may need to update the transfer mode if the
3412 * device doesn't work with its default. They may likewise need
3413 * to update clock rates or word sizes from initial values. This function
3414 * changes those settings, and must be called from a context that can sleep.
3415 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3416 * effect the next time the device is selected and data is transferred to
3417 * or from it. When this function returns, the spi device is deselected.
3419 * Note that this call will fail if the protocol driver specifies an option
3420 * that the underlying controller or its driver does not support. For
3421 * example, not all hardware supports wire transfers using nine bit words,
3422 * LSB-first wire encoding, or active-high chipselects.
3424 * Return: zero on success, else a negative error code.
3426 int spi_setup(struct spi_device
*spi
)
3428 unsigned bad_bits
, ugly_bits
;
3432 * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
3433 * are set at the same time
3435 if ((hweight_long(spi
->mode
&
3436 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_NO_TX
)) > 1) ||
3437 (hweight_long(spi
->mode
&
3438 (SPI_RX_DUAL
| SPI_RX_QUAD
| SPI_NO_RX
)) > 1)) {
3440 "setup: can not select any two of dual, quad and no-rx/tx at the same time\n");
3443 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
3445 if ((spi
->mode
& SPI_3WIRE
) && (spi
->mode
&
3446 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_TX_OCTAL
|
3447 SPI_RX_DUAL
| SPI_RX_QUAD
| SPI_RX_OCTAL
)))
3449 /* help drivers fail *cleanly* when they need options
3450 * that aren't supported with their current controller
3451 * SPI_CS_WORD has a fallback software implementation,
3452 * so it is ignored here.
3454 bad_bits
= spi
->mode
& ~(spi
->controller
->mode_bits
| SPI_CS_WORD
|
3455 SPI_NO_TX
| SPI_NO_RX
);
3456 /* nothing prevents from working with active-high CS in case if it
3457 * is driven by GPIO.
3459 if (gpio_is_valid(spi
->cs_gpio
))
3460 bad_bits
&= ~SPI_CS_HIGH
;
3461 ugly_bits
= bad_bits
&
3462 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_TX_OCTAL
|
3463 SPI_RX_DUAL
| SPI_RX_QUAD
| SPI_RX_OCTAL
);
3466 "setup: ignoring unsupported mode bits %x\n",
3468 spi
->mode
&= ~ugly_bits
;
3469 bad_bits
&= ~ugly_bits
;
3472 dev_err(&spi
->dev
, "setup: unsupported mode bits %x\n",
3477 if (!spi
->bits_per_word
)
3478 spi
->bits_per_word
= 8;
3480 status
= __spi_validate_bits_per_word(spi
->controller
,
3481 spi
->bits_per_word
);
3485 if (spi
->controller
->max_speed_hz
&&
3486 (!spi
->max_speed_hz
||
3487 spi
->max_speed_hz
> spi
->controller
->max_speed_hz
))
3488 spi
->max_speed_hz
= spi
->controller
->max_speed_hz
;
3490 mutex_lock(&spi
->controller
->io_mutex
);
3492 if (spi
->controller
->setup
) {
3493 status
= spi
->controller
->setup(spi
);
3495 mutex_unlock(&spi
->controller
->io_mutex
);
3496 dev_err(&spi
->controller
->dev
, "Failed to setup device: %d\n",
3502 if (spi
->controller
->auto_runtime_pm
&& spi
->controller
->set_cs
) {
3503 status
= pm_runtime_get_sync(spi
->controller
->dev
.parent
);
3505 mutex_unlock(&spi
->controller
->io_mutex
);
3506 pm_runtime_put_noidle(spi
->controller
->dev
.parent
);
3507 dev_err(&spi
->controller
->dev
, "Failed to power device: %d\n",
3513 * We do not want to return positive value from pm_runtime_get,
3514 * there are many instances of devices calling spi_setup() and
3515 * checking for a non-zero return value instead of a negative
3520 spi_set_cs(spi
, false, true);
3521 pm_runtime_mark_last_busy(spi
->controller
->dev
.parent
);
3522 pm_runtime_put_autosuspend(spi
->controller
->dev
.parent
);
3524 spi_set_cs(spi
, false, true);
3527 mutex_unlock(&spi
->controller
->io_mutex
);
3529 if (spi
->rt
&& !spi
->controller
->rt
) {
3530 spi
->controller
->rt
= true;
3531 spi_set_thread_rt(spi
->controller
);
3534 trace_spi_setup(spi
, status
);
3536 dev_dbg(&spi
->dev
, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3537 spi
->mode
& SPI_MODE_X_MASK
,
3538 (spi
->mode
& SPI_CS_HIGH
) ? "cs_high, " : "",
3539 (spi
->mode
& SPI_LSB_FIRST
) ? "lsb, " : "",
3540 (spi
->mode
& SPI_3WIRE
) ? "3wire, " : "",
3541 (spi
->mode
& SPI_LOOP
) ? "loopback, " : "",
3542 spi
->bits_per_word
, spi
->max_speed_hz
,
3547 EXPORT_SYMBOL_GPL(spi_setup
);
3549 static int _spi_xfer_word_delay_update(struct spi_transfer
*xfer
,
3550 struct spi_device
*spi
)
3554 delay1
= spi_delay_to_ns(&xfer
->word_delay
, xfer
);
3558 delay2
= spi_delay_to_ns(&spi
->word_delay
, xfer
);
3562 if (delay1
< delay2
)
3563 memcpy(&xfer
->word_delay
, &spi
->word_delay
,
3564 sizeof(xfer
->word_delay
));
3569 static int __spi_validate(struct spi_device
*spi
, struct spi_message
*message
)
3571 struct spi_controller
*ctlr
= spi
->controller
;
3572 struct spi_transfer
*xfer
;
3575 if (list_empty(&message
->transfers
))
3578 /* If an SPI controller does not support toggling the CS line on each
3579 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3580 * for the CS line, we can emulate the CS-per-word hardware function by
3581 * splitting transfers into one-word transfers and ensuring that
3582 * cs_change is set for each transfer.
3584 if ((spi
->mode
& SPI_CS_WORD
) && (!(ctlr
->mode_bits
& SPI_CS_WORD
) ||
3586 gpio_is_valid(spi
->cs_gpio
))) {
3590 maxsize
= (spi
->bits_per_word
+ 7) / 8;
3592 /* spi_split_transfers_maxsize() requires message->spi */
3595 ret
= spi_split_transfers_maxsize(ctlr
, message
, maxsize
,
3600 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
3601 /* don't change cs_change on the last entry in the list */
3602 if (list_is_last(&xfer
->transfer_list
, &message
->transfers
))
3604 xfer
->cs_change
= 1;
3608 /* Half-duplex links include original MicroWire, and ones with
3609 * only one data pin like SPI_3WIRE (switches direction) or where
3610 * either MOSI or MISO is missing. They can also be caused by
3611 * software limitations.
3613 if ((ctlr
->flags
& SPI_CONTROLLER_HALF_DUPLEX
) ||
3614 (spi
->mode
& SPI_3WIRE
)) {
3615 unsigned flags
= ctlr
->flags
;
3617 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
3618 if (xfer
->rx_buf
&& xfer
->tx_buf
)
3620 if ((flags
& SPI_CONTROLLER_NO_TX
) && xfer
->tx_buf
)
3622 if ((flags
& SPI_CONTROLLER_NO_RX
) && xfer
->rx_buf
)
3628 * Set transfer bits_per_word and max speed as spi device default if
3629 * it is not set for this transfer.
3630 * Set transfer tx_nbits and rx_nbits as single transfer default
3631 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3632 * Ensure transfer word_delay is at least as long as that required by
3635 message
->frame_length
= 0;
3636 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
3637 xfer
->effective_speed_hz
= 0;
3638 message
->frame_length
+= xfer
->len
;
3639 if (!xfer
->bits_per_word
)
3640 xfer
->bits_per_word
= spi
->bits_per_word
;
3642 if (!xfer
->speed_hz
)
3643 xfer
->speed_hz
= spi
->max_speed_hz
;
3645 if (ctlr
->max_speed_hz
&& xfer
->speed_hz
> ctlr
->max_speed_hz
)
3646 xfer
->speed_hz
= ctlr
->max_speed_hz
;
3648 if (__spi_validate_bits_per_word(ctlr
, xfer
->bits_per_word
))
3652 * SPI transfer length should be multiple of SPI word size
3653 * where SPI word size should be power-of-two multiple
3655 if (xfer
->bits_per_word
<= 8)
3657 else if (xfer
->bits_per_word
<= 16)
3662 /* No partial transfers accepted */
3663 if (xfer
->len
% w_size
)
3666 if (xfer
->speed_hz
&& ctlr
->min_speed_hz
&&
3667 xfer
->speed_hz
< ctlr
->min_speed_hz
)
3670 if (xfer
->tx_buf
&& !xfer
->tx_nbits
)
3671 xfer
->tx_nbits
= SPI_NBITS_SINGLE
;
3672 if (xfer
->rx_buf
&& !xfer
->rx_nbits
)
3673 xfer
->rx_nbits
= SPI_NBITS_SINGLE
;
3674 /* check transfer tx/rx_nbits:
3675 * 1. check the value matches one of single, dual and quad
3676 * 2. check tx/rx_nbits match the mode in spi_device
3679 if (spi
->mode
& SPI_NO_TX
)
3681 if (xfer
->tx_nbits
!= SPI_NBITS_SINGLE
&&
3682 xfer
->tx_nbits
!= SPI_NBITS_DUAL
&&
3683 xfer
->tx_nbits
!= SPI_NBITS_QUAD
)
3685 if ((xfer
->tx_nbits
== SPI_NBITS_DUAL
) &&
3686 !(spi
->mode
& (SPI_TX_DUAL
| SPI_TX_QUAD
)))
3688 if ((xfer
->tx_nbits
== SPI_NBITS_QUAD
) &&
3689 !(spi
->mode
& SPI_TX_QUAD
))
3692 /* check transfer rx_nbits */
3694 if (spi
->mode
& SPI_NO_RX
)
3696 if (xfer
->rx_nbits
!= SPI_NBITS_SINGLE
&&
3697 xfer
->rx_nbits
!= SPI_NBITS_DUAL
&&
3698 xfer
->rx_nbits
!= SPI_NBITS_QUAD
)
3700 if ((xfer
->rx_nbits
== SPI_NBITS_DUAL
) &&
3701 !(spi
->mode
& (SPI_RX_DUAL
| SPI_RX_QUAD
)))
3703 if ((xfer
->rx_nbits
== SPI_NBITS_QUAD
) &&
3704 !(spi
->mode
& SPI_RX_QUAD
))
3708 if (_spi_xfer_word_delay_update(xfer
, spi
))
3712 message
->status
= -EINPROGRESS
;
3717 static int __spi_async(struct spi_device
*spi
, struct spi_message
*message
)
3719 struct spi_controller
*ctlr
= spi
->controller
;
3720 struct spi_transfer
*xfer
;
3723 * Some controllers do not support doing regular SPI transfers. Return
3724 * ENOTSUPP when this is the case.
3726 if (!ctlr
->transfer
)
3731 SPI_STATISTICS_INCREMENT_FIELD(&ctlr
->statistics
, spi_async
);
3732 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
, spi_async
);
3734 trace_spi_message_submit(message
);
3736 if (!ctlr
->ptp_sts_supported
) {
3737 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
3738 xfer
->ptp_sts_word_pre
= 0;
3739 ptp_read_system_prets(xfer
->ptp_sts
);
3743 return ctlr
->transfer(spi
, message
);
3747 * spi_async - asynchronous SPI transfer
3748 * @spi: device with which data will be exchanged
3749 * @message: describes the data transfers, including completion callback
3750 * Context: any (irqs may be blocked, etc)
3752 * This call may be used in_irq and other contexts which can't sleep,
3753 * as well as from task contexts which can sleep.
3755 * The completion callback is invoked in a context which can't sleep.
3756 * Before that invocation, the value of message->status is undefined.
3757 * When the callback is issued, message->status holds either zero (to
3758 * indicate complete success) or a negative error code. After that
3759 * callback returns, the driver which issued the transfer request may
3760 * deallocate the associated memory; it's no longer in use by any SPI
3761 * core or controller driver code.
3763 * Note that although all messages to a spi_device are handled in
3764 * FIFO order, messages may go to different devices in other orders.
3765 * Some device might be higher priority, or have various "hard" access
3766 * time requirements, for example.
3768 * On detection of any fault during the transfer, processing of
3769 * the entire message is aborted, and the device is deselected.
3770 * Until returning from the associated message completion callback,
3771 * no other spi_message queued to that device will be processed.
3772 * (This rule applies equally to all the synchronous transfer calls,
3773 * which are wrappers around this core asynchronous primitive.)
3775 * Return: zero on success, else a negative error code.
3777 int spi_async(struct spi_device
*spi
, struct spi_message
*message
)
3779 struct spi_controller
*ctlr
= spi
->controller
;
3781 unsigned long flags
;
3783 ret
= __spi_validate(spi
, message
);
3787 spin_lock_irqsave(&ctlr
->bus_lock_spinlock
, flags
);
3789 if (ctlr
->bus_lock_flag
)
3792 ret
= __spi_async(spi
, message
);
3794 spin_unlock_irqrestore(&ctlr
->bus_lock_spinlock
, flags
);
3798 EXPORT_SYMBOL_GPL(spi_async
);
3801 * spi_async_locked - version of spi_async with exclusive bus usage
3802 * @spi: device with which data will be exchanged
3803 * @message: describes the data transfers, including completion callback
3804 * Context: any (irqs may be blocked, etc)
3806 * This call may be used in_irq and other contexts which can't sleep,
3807 * as well as from task contexts which can sleep.
3809 * The completion callback is invoked in a context which can't sleep.
3810 * Before that invocation, the value of message->status is undefined.
3811 * When the callback is issued, message->status holds either zero (to
3812 * indicate complete success) or a negative error code. After that
3813 * callback returns, the driver which issued the transfer request may
3814 * deallocate the associated memory; it's no longer in use by any SPI
3815 * core or controller driver code.
3817 * Note that although all messages to a spi_device are handled in
3818 * FIFO order, messages may go to different devices in other orders.
3819 * Some device might be higher priority, or have various "hard" access
3820 * time requirements, for example.
3822 * On detection of any fault during the transfer, processing of
3823 * the entire message is aborted, and the device is deselected.
3824 * Until returning from the associated message completion callback,
3825 * no other spi_message queued to that device will be processed.
3826 * (This rule applies equally to all the synchronous transfer calls,
3827 * which are wrappers around this core asynchronous primitive.)
3829 * Return: zero on success, else a negative error code.
3831 int spi_async_locked(struct spi_device
*spi
, struct spi_message
*message
)
3833 struct spi_controller
*ctlr
= spi
->controller
;
3835 unsigned long flags
;
3837 ret
= __spi_validate(spi
, message
);
3841 spin_lock_irqsave(&ctlr
->bus_lock_spinlock
, flags
);
3843 ret
= __spi_async(spi
, message
);
3845 spin_unlock_irqrestore(&ctlr
->bus_lock_spinlock
, flags
);
3850 EXPORT_SYMBOL_GPL(spi_async_locked
);
3852 /*-------------------------------------------------------------------------*/
3854 /* Utility methods for SPI protocol drivers, layered on
3855 * top of the core. Some other utility methods are defined as
3859 static void spi_complete(void *arg
)
3864 static int __spi_sync(struct spi_device
*spi
, struct spi_message
*message
)
3866 DECLARE_COMPLETION_ONSTACK(done
);
3868 struct spi_controller
*ctlr
= spi
->controller
;
3869 unsigned long flags
;
3871 status
= __spi_validate(spi
, message
);
3875 message
->complete
= spi_complete
;
3876 message
->context
= &done
;
3879 SPI_STATISTICS_INCREMENT_FIELD(&ctlr
->statistics
, spi_sync
);
3880 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
, spi_sync
);
3882 /* If we're not using the legacy transfer method then we will
3883 * try to transfer in the calling context so special case.
3884 * This code would be less tricky if we could remove the
3885 * support for driver implemented message queues.
3887 if (ctlr
->transfer
== spi_queued_transfer
) {
3888 spin_lock_irqsave(&ctlr
->bus_lock_spinlock
, flags
);
3890 trace_spi_message_submit(message
);
3892 status
= __spi_queued_transfer(spi
, message
, false);
3894 spin_unlock_irqrestore(&ctlr
->bus_lock_spinlock
, flags
);
3896 status
= spi_async_locked(spi
, message
);
3900 /* Push out the messages in the calling context if we
3903 if (ctlr
->transfer
== spi_queued_transfer
) {
3904 SPI_STATISTICS_INCREMENT_FIELD(&ctlr
->statistics
,
3905 spi_sync_immediate
);
3906 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
,
3907 spi_sync_immediate
);
3908 __spi_pump_messages(ctlr
, false);
3911 wait_for_completion(&done
);
3912 status
= message
->status
;
3914 message
->context
= NULL
;
3919 * spi_sync - blocking/synchronous SPI data transfers
3920 * @spi: device with which data will be exchanged
3921 * @message: describes the data transfers
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. Low-overhead controller
3926 * drivers may DMA directly into and out of the message buffers.
3928 * Note that the SPI device's chip select is active during the message,
3929 * and then is normally disabled between messages. Drivers for some
3930 * frequently-used devices may want to minimize costs of selecting a chip,
3931 * by leaving it selected in anticipation that the next message will go
3932 * to the same chip. (That may increase power usage.)
3934 * Also, the caller is guaranteeing that the memory associated with the
3935 * message will not be freed before this call returns.
3937 * Return: zero on success, else a negative error code.
3939 int spi_sync(struct spi_device
*spi
, struct spi_message
*message
)
3943 mutex_lock(&spi
->controller
->bus_lock_mutex
);
3944 ret
= __spi_sync(spi
, message
);
3945 mutex_unlock(&spi
->controller
->bus_lock_mutex
);
3949 EXPORT_SYMBOL_GPL(spi_sync
);
3952 * spi_sync_locked - version of spi_sync with exclusive bus usage
3953 * @spi: device with which data will be exchanged
3954 * @message: describes the data transfers
3955 * Context: can sleep
3957 * This call may only be used from a context that may sleep. The sleep
3958 * is non-interruptible, and has no timeout. Low-overhead controller
3959 * drivers may DMA directly into and out of the message buffers.
3961 * This call should be used by drivers that require exclusive access to the
3962 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3963 * be released by a spi_bus_unlock call when the exclusive access is over.
3965 * Return: zero on success, else a negative error code.
3967 int spi_sync_locked(struct spi_device
*spi
, struct spi_message
*message
)
3969 return __spi_sync(spi
, message
);
3971 EXPORT_SYMBOL_GPL(spi_sync_locked
);
3974 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3975 * @ctlr: SPI bus master that should be locked for exclusive bus access
3976 * Context: can sleep
3978 * This call may only be used from a context that may sleep. The sleep
3979 * is non-interruptible, and has no timeout.
3981 * This call should be used by drivers that require exclusive access to the
3982 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3983 * exclusive access is over. Data transfer must be done by spi_sync_locked
3984 * and spi_async_locked calls when the SPI bus lock is held.
3986 * Return: always zero.
3988 int spi_bus_lock(struct spi_controller
*ctlr
)
3990 unsigned long flags
;
3992 mutex_lock(&ctlr
->bus_lock_mutex
);
3994 spin_lock_irqsave(&ctlr
->bus_lock_spinlock
, flags
);
3995 ctlr
->bus_lock_flag
= 1;
3996 spin_unlock_irqrestore(&ctlr
->bus_lock_spinlock
, flags
);
3998 /* mutex remains locked until spi_bus_unlock is called */
4002 EXPORT_SYMBOL_GPL(spi_bus_lock
);
4005 * spi_bus_unlock - release the lock for exclusive SPI bus usage
4006 * @ctlr: SPI bus master that was locked for exclusive bus access
4007 * Context: can sleep
4009 * This call may only be used from a context that may sleep. The sleep
4010 * is non-interruptible, and has no timeout.
4012 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
4015 * Return: always zero.
4017 int spi_bus_unlock(struct spi_controller
*ctlr
)
4019 ctlr
->bus_lock_flag
= 0;
4021 mutex_unlock(&ctlr
->bus_lock_mutex
);
4025 EXPORT_SYMBOL_GPL(spi_bus_unlock
);
4027 /* portable code must never pass more than 32 bytes */
4028 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
4033 * spi_write_then_read - SPI synchronous write followed by read
4034 * @spi: device with which data will be exchanged
4035 * @txbuf: data to be written (need not be dma-safe)
4036 * @n_tx: size of txbuf, in bytes
4037 * @rxbuf: buffer into which data will be read (need not be dma-safe)
4038 * @n_rx: size of rxbuf, in bytes
4039 * Context: can sleep
4041 * This performs a half duplex MicroWire style transaction with the
4042 * device, sending txbuf and then reading rxbuf. The return value
4043 * is zero for success, else a negative errno status code.
4044 * This call may only be used from a context that may sleep.
4046 * Parameters to this routine are always copied using a small buffer.
4047 * Performance-sensitive or bulk transfer code should instead use
4048 * spi_{async,sync}() calls with dma-safe buffers.
4050 * Return: zero on success, else a negative error code.
4052 int spi_write_then_read(struct spi_device
*spi
,
4053 const void *txbuf
, unsigned n_tx
,
4054 void *rxbuf
, unsigned n_rx
)
4056 static DEFINE_MUTEX(lock
);
4059 struct spi_message message
;
4060 struct spi_transfer x
[2];
4063 /* Use preallocated DMA-safe buffer if we can. We can't avoid
4064 * copying here, (as a pure convenience thing), but we can
4065 * keep heap costs out of the hot path unless someone else is
4066 * using the pre-allocated buffer or the transfer is too large.
4068 if ((n_tx
+ n_rx
) > SPI_BUFSIZ
|| !mutex_trylock(&lock
)) {
4069 local_buf
= kmalloc(max((unsigned)SPI_BUFSIZ
, n_tx
+ n_rx
),
4070 GFP_KERNEL
| GFP_DMA
);
4077 spi_message_init(&message
);
4078 memset(x
, 0, sizeof(x
));
4081 spi_message_add_tail(&x
[0], &message
);
4085 spi_message_add_tail(&x
[1], &message
);
4088 memcpy(local_buf
, txbuf
, n_tx
);
4089 x
[0].tx_buf
= local_buf
;
4090 x
[1].rx_buf
= local_buf
+ n_tx
;
4093 status
= spi_sync(spi
, &message
);
4095 memcpy(rxbuf
, x
[1].rx_buf
, n_rx
);
4097 if (x
[0].tx_buf
== buf
)
4098 mutex_unlock(&lock
);
4104 EXPORT_SYMBOL_GPL(spi_write_then_read
);
4106 /*-------------------------------------------------------------------------*/
4108 #if IS_ENABLED(CONFIG_OF)
4109 /* must call put_device() when done with returned spi_device device */
4110 struct spi_device
*of_find_spi_device_by_node(struct device_node
*node
)
4112 struct device
*dev
= bus_find_device_by_of_node(&spi_bus_type
, node
);
4114 return dev
? to_spi_device(dev
) : NULL
;
4116 EXPORT_SYMBOL_GPL(of_find_spi_device_by_node
);
4117 #endif /* IS_ENABLED(CONFIG_OF) */
4119 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
4120 /* the spi controllers are not using spi_bus, so we find it with another way */
4121 static struct spi_controller
*of_find_spi_controller_by_node(struct device_node
*node
)
4125 dev
= class_find_device_by_of_node(&spi_master_class
, node
);
4126 if (!dev
&& IS_ENABLED(CONFIG_SPI_SLAVE
))
4127 dev
= class_find_device_by_of_node(&spi_slave_class
, node
);
4131 /* reference got in class_find_device */
4132 return container_of(dev
, struct spi_controller
, dev
);
4135 static int of_spi_notify(struct notifier_block
*nb
, unsigned long action
,
4138 struct of_reconfig_data
*rd
= arg
;
4139 struct spi_controller
*ctlr
;
4140 struct spi_device
*spi
;
4142 switch (of_reconfig_get_state_change(action
, arg
)) {
4143 case OF_RECONFIG_CHANGE_ADD
:
4144 ctlr
= of_find_spi_controller_by_node(rd
->dn
->parent
);
4146 return NOTIFY_OK
; /* not for us */
4148 if (of_node_test_and_set_flag(rd
->dn
, OF_POPULATED
)) {
4149 put_device(&ctlr
->dev
);
4153 spi
= of_register_spi_device(ctlr
, rd
->dn
);
4154 put_device(&ctlr
->dev
);
4157 pr_err("%s: failed to create for '%pOF'\n",
4159 of_node_clear_flag(rd
->dn
, OF_POPULATED
);
4160 return notifier_from_errno(PTR_ERR(spi
));
4164 case OF_RECONFIG_CHANGE_REMOVE
:
4165 /* already depopulated? */
4166 if (!of_node_check_flag(rd
->dn
, OF_POPULATED
))
4169 /* find our device by node */
4170 spi
= of_find_spi_device_by_node(rd
->dn
);
4172 return NOTIFY_OK
; /* no? not meant for us */
4174 /* unregister takes one ref away */
4175 spi_unregister_device(spi
);
4177 /* and put the reference of the find */
4178 put_device(&spi
->dev
);
4185 static struct notifier_block spi_of_notifier
= {
4186 .notifier_call
= of_spi_notify
,
4188 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4189 extern struct notifier_block spi_of_notifier
;
4190 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4192 #if IS_ENABLED(CONFIG_ACPI)
4193 static int spi_acpi_controller_match(struct device
*dev
, const void *data
)
4195 return ACPI_COMPANION(dev
->parent
) == data
;
4198 static struct spi_controller
*acpi_spi_find_controller_by_adev(struct acpi_device
*adev
)
4202 dev
= class_find_device(&spi_master_class
, NULL
, adev
,
4203 spi_acpi_controller_match
);
4204 if (!dev
&& IS_ENABLED(CONFIG_SPI_SLAVE
))
4205 dev
= class_find_device(&spi_slave_class
, NULL
, adev
,
4206 spi_acpi_controller_match
);
4210 return container_of(dev
, struct spi_controller
, dev
);
4213 static struct spi_device
*acpi_spi_find_device_by_adev(struct acpi_device
*adev
)
4217 dev
= bus_find_device_by_acpi_dev(&spi_bus_type
, adev
);
4218 return to_spi_device(dev
);
4221 static int acpi_spi_notify(struct notifier_block
*nb
, unsigned long value
,
4224 struct acpi_device
*adev
= arg
;
4225 struct spi_controller
*ctlr
;
4226 struct spi_device
*spi
;
4229 case ACPI_RECONFIG_DEVICE_ADD
:
4230 ctlr
= acpi_spi_find_controller_by_adev(adev
->parent
);
4234 acpi_register_spi_device(ctlr
, adev
);
4235 put_device(&ctlr
->dev
);
4237 case ACPI_RECONFIG_DEVICE_REMOVE
:
4238 if (!acpi_device_enumerated(adev
))
4241 spi
= acpi_spi_find_device_by_adev(adev
);
4245 spi_unregister_device(spi
);
4246 put_device(&spi
->dev
);
4253 static struct notifier_block spi_acpi_notifier
= {
4254 .notifier_call
= acpi_spi_notify
,
4257 extern struct notifier_block spi_acpi_notifier
;
4260 static int __init
spi_init(void)
4264 buf
= kmalloc(SPI_BUFSIZ
, GFP_KERNEL
);
4270 status
= bus_register(&spi_bus_type
);
4274 status
= class_register(&spi_master_class
);
4278 if (IS_ENABLED(CONFIG_SPI_SLAVE
)) {
4279 status
= class_register(&spi_slave_class
);
4284 if (IS_ENABLED(CONFIG_OF_DYNAMIC
))
4285 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier
));
4286 if (IS_ENABLED(CONFIG_ACPI
))
4287 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier
));
4292 class_unregister(&spi_master_class
);
4294 bus_unregister(&spi_bus_type
);
4302 /* board_info is normally registered in arch_initcall(),
4303 * but even essential drivers wait till later
4305 * REVISIT only boardinfo really needs static linking. the rest (device and
4306 * driver registration) _could_ be dynamically linked (modular) ... costs
4307 * include needing to have boardinfo data structures be much more public.
4309 postcore_initcall(spi_init
);