4 * Copyright (C) 2005 David Brownell
5 * Copyright (C) 2008 Secret Lab Technologies Ltd.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
18 #include <linux/kernel.h>
19 #include <linux/device.h>
20 #include <linux/init.h>
21 #include <linux/cache.h>
22 #include <linux/dma-mapping.h>
23 #include <linux/dmaengine.h>
24 #include <linux/mutex.h>
25 #include <linux/of_device.h>
26 #include <linux/of_irq.h>
27 #include <linux/clk/clk-conf.h>
28 #include <linux/slab.h>
29 #include <linux/mod_devicetable.h>
30 #include <linux/spi/spi.h>
31 #include <linux/of_gpio.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/pm_domain.h>
34 #include <linux/export.h>
35 #include <linux/sched/rt.h>
36 #include <linux/delay.h>
37 #include <linux/kthread.h>
38 #include <linux/ioport.h>
39 #include <linux/acpi.h>
40 #include <linux/highmem.h>
42 #define CREATE_TRACE_POINTS
43 #include <trace/events/spi.h>
45 static void spidev_release(struct device
*dev
)
47 struct spi_device
*spi
= to_spi_device(dev
);
49 /* spi masters may cleanup for released devices */
50 if (spi
->master
->cleanup
)
51 spi
->master
->cleanup(spi
);
53 spi_master_put(spi
->master
);
58 modalias_show(struct device
*dev
, struct device_attribute
*a
, char *buf
)
60 const struct spi_device
*spi
= to_spi_device(dev
);
63 len
= acpi_device_modalias(dev
, buf
, PAGE_SIZE
- 1);
67 return sprintf(buf
, "%s%s\n", SPI_MODULE_PREFIX
, spi
->modalias
);
69 static DEVICE_ATTR_RO(modalias
);
71 #define SPI_STATISTICS_ATTRS(field, file) \
72 static ssize_t spi_master_##field##_show(struct device *dev, \
73 struct device_attribute *attr, \
76 struct spi_master *master = container_of(dev, \
77 struct spi_master, dev); \
78 return spi_statistics_##field##_show(&master->statistics, buf); \
80 static struct device_attribute dev_attr_spi_master_##field = { \
81 .attr = { .name = file, .mode = S_IRUGO }, \
82 .show = spi_master_##field##_show, \
84 static ssize_t spi_device_##field##_show(struct device *dev, \
85 struct device_attribute *attr, \
88 struct spi_device *spi = to_spi_device(dev); \
89 return spi_statistics_##field##_show(&spi->statistics, buf); \
91 static struct device_attribute dev_attr_spi_device_##field = { \
92 .attr = { .name = file, .mode = S_IRUGO }, \
93 .show = spi_device_##field##_show, \
96 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
97 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
100 unsigned long flags; \
102 spin_lock_irqsave(&stat->lock, flags); \
103 len = sprintf(buf, format_string, stat->field); \
104 spin_unlock_irqrestore(&stat->lock, flags); \
107 SPI_STATISTICS_ATTRS(name, file)
109 #define SPI_STATISTICS_SHOW(field, format_string) \
110 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
111 field, format_string)
113 SPI_STATISTICS_SHOW(messages
, "%lu");
114 SPI_STATISTICS_SHOW(transfers
, "%lu");
115 SPI_STATISTICS_SHOW(errors
, "%lu");
116 SPI_STATISTICS_SHOW(timedout
, "%lu");
118 SPI_STATISTICS_SHOW(spi_sync
, "%lu");
119 SPI_STATISTICS_SHOW(spi_sync_immediate
, "%lu");
120 SPI_STATISTICS_SHOW(spi_async
, "%lu");
122 SPI_STATISTICS_SHOW(bytes
, "%llu");
123 SPI_STATISTICS_SHOW(bytes_rx
, "%llu");
124 SPI_STATISTICS_SHOW(bytes_tx
, "%llu");
126 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
127 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
128 "transfer_bytes_histo_" number, \
129 transfer_bytes_histo[index], "%lu")
130 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
131 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
132 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
133 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
134 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
135 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
136 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
137 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
138 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
139 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
140 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
141 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
142 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
143 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
144 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
145 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
146 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
148 SPI_STATISTICS_SHOW(transfers_split_maxsize
, "%lu");
150 static struct attribute
*spi_dev_attrs
[] = {
151 &dev_attr_modalias
.attr
,
155 static const struct attribute_group spi_dev_group
= {
156 .attrs
= spi_dev_attrs
,
159 static struct attribute
*spi_device_statistics_attrs
[] = {
160 &dev_attr_spi_device_messages
.attr
,
161 &dev_attr_spi_device_transfers
.attr
,
162 &dev_attr_spi_device_errors
.attr
,
163 &dev_attr_spi_device_timedout
.attr
,
164 &dev_attr_spi_device_spi_sync
.attr
,
165 &dev_attr_spi_device_spi_sync_immediate
.attr
,
166 &dev_attr_spi_device_spi_async
.attr
,
167 &dev_attr_spi_device_bytes
.attr
,
168 &dev_attr_spi_device_bytes_rx
.attr
,
169 &dev_attr_spi_device_bytes_tx
.attr
,
170 &dev_attr_spi_device_transfer_bytes_histo0
.attr
,
171 &dev_attr_spi_device_transfer_bytes_histo1
.attr
,
172 &dev_attr_spi_device_transfer_bytes_histo2
.attr
,
173 &dev_attr_spi_device_transfer_bytes_histo3
.attr
,
174 &dev_attr_spi_device_transfer_bytes_histo4
.attr
,
175 &dev_attr_spi_device_transfer_bytes_histo5
.attr
,
176 &dev_attr_spi_device_transfer_bytes_histo6
.attr
,
177 &dev_attr_spi_device_transfer_bytes_histo7
.attr
,
178 &dev_attr_spi_device_transfer_bytes_histo8
.attr
,
179 &dev_attr_spi_device_transfer_bytes_histo9
.attr
,
180 &dev_attr_spi_device_transfer_bytes_histo10
.attr
,
181 &dev_attr_spi_device_transfer_bytes_histo11
.attr
,
182 &dev_attr_spi_device_transfer_bytes_histo12
.attr
,
183 &dev_attr_spi_device_transfer_bytes_histo13
.attr
,
184 &dev_attr_spi_device_transfer_bytes_histo14
.attr
,
185 &dev_attr_spi_device_transfer_bytes_histo15
.attr
,
186 &dev_attr_spi_device_transfer_bytes_histo16
.attr
,
187 &dev_attr_spi_device_transfers_split_maxsize
.attr
,
191 static const struct attribute_group spi_device_statistics_group
= {
192 .name
= "statistics",
193 .attrs
= spi_device_statistics_attrs
,
196 static const struct attribute_group
*spi_dev_groups
[] = {
198 &spi_device_statistics_group
,
202 static struct attribute
*spi_master_statistics_attrs
[] = {
203 &dev_attr_spi_master_messages
.attr
,
204 &dev_attr_spi_master_transfers
.attr
,
205 &dev_attr_spi_master_errors
.attr
,
206 &dev_attr_spi_master_timedout
.attr
,
207 &dev_attr_spi_master_spi_sync
.attr
,
208 &dev_attr_spi_master_spi_sync_immediate
.attr
,
209 &dev_attr_spi_master_spi_async
.attr
,
210 &dev_attr_spi_master_bytes
.attr
,
211 &dev_attr_spi_master_bytes_rx
.attr
,
212 &dev_attr_spi_master_bytes_tx
.attr
,
213 &dev_attr_spi_master_transfer_bytes_histo0
.attr
,
214 &dev_attr_spi_master_transfer_bytes_histo1
.attr
,
215 &dev_attr_spi_master_transfer_bytes_histo2
.attr
,
216 &dev_attr_spi_master_transfer_bytes_histo3
.attr
,
217 &dev_attr_spi_master_transfer_bytes_histo4
.attr
,
218 &dev_attr_spi_master_transfer_bytes_histo5
.attr
,
219 &dev_attr_spi_master_transfer_bytes_histo6
.attr
,
220 &dev_attr_spi_master_transfer_bytes_histo7
.attr
,
221 &dev_attr_spi_master_transfer_bytes_histo8
.attr
,
222 &dev_attr_spi_master_transfer_bytes_histo9
.attr
,
223 &dev_attr_spi_master_transfer_bytes_histo10
.attr
,
224 &dev_attr_spi_master_transfer_bytes_histo11
.attr
,
225 &dev_attr_spi_master_transfer_bytes_histo12
.attr
,
226 &dev_attr_spi_master_transfer_bytes_histo13
.attr
,
227 &dev_attr_spi_master_transfer_bytes_histo14
.attr
,
228 &dev_attr_spi_master_transfer_bytes_histo15
.attr
,
229 &dev_attr_spi_master_transfer_bytes_histo16
.attr
,
230 &dev_attr_spi_master_transfers_split_maxsize
.attr
,
234 static const struct attribute_group spi_master_statistics_group
= {
235 .name
= "statistics",
236 .attrs
= spi_master_statistics_attrs
,
239 static const struct attribute_group
*spi_master_groups
[] = {
240 &spi_master_statistics_group
,
244 void spi_statistics_add_transfer_stats(struct spi_statistics
*stats
,
245 struct spi_transfer
*xfer
,
246 struct spi_master
*master
)
249 int l2len
= min(fls(xfer
->len
), SPI_STATISTICS_HISTO_SIZE
) - 1;
254 spin_lock_irqsave(&stats
->lock
, flags
);
257 stats
->transfer_bytes_histo
[l2len
]++;
259 stats
->bytes
+= xfer
->len
;
260 if ((xfer
->tx_buf
) &&
261 (xfer
->tx_buf
!= master
->dummy_tx
))
262 stats
->bytes_tx
+= xfer
->len
;
263 if ((xfer
->rx_buf
) &&
264 (xfer
->rx_buf
!= master
->dummy_rx
))
265 stats
->bytes_rx
+= xfer
->len
;
267 spin_unlock_irqrestore(&stats
->lock
, flags
);
269 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats
);
271 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
272 * and the sysfs version makes coldplug work too.
275 static const struct spi_device_id
*spi_match_id(const struct spi_device_id
*id
,
276 const struct spi_device
*sdev
)
278 while (id
->name
[0]) {
279 if (!strcmp(sdev
->modalias
, id
->name
))
286 const struct spi_device_id
*spi_get_device_id(const struct spi_device
*sdev
)
288 const struct spi_driver
*sdrv
= to_spi_driver(sdev
->dev
.driver
);
290 return spi_match_id(sdrv
->id_table
, sdev
);
292 EXPORT_SYMBOL_GPL(spi_get_device_id
);
294 static int spi_match_device(struct device
*dev
, struct device_driver
*drv
)
296 const struct spi_device
*spi
= to_spi_device(dev
);
297 const struct spi_driver
*sdrv
= to_spi_driver(drv
);
299 /* Attempt an OF style match */
300 if (of_driver_match_device(dev
, drv
))
304 if (acpi_driver_match_device(dev
, drv
))
308 return !!spi_match_id(sdrv
->id_table
, spi
);
310 return strcmp(spi
->modalias
, drv
->name
) == 0;
313 static int spi_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
315 const struct spi_device
*spi
= to_spi_device(dev
);
318 rc
= acpi_device_uevent_modalias(dev
, env
);
322 add_uevent_var(env
, "MODALIAS=%s%s", SPI_MODULE_PREFIX
, spi
->modalias
);
326 struct bus_type spi_bus_type
= {
328 .dev_groups
= spi_dev_groups
,
329 .match
= spi_match_device
,
330 .uevent
= spi_uevent
,
332 EXPORT_SYMBOL_GPL(spi_bus_type
);
335 static int spi_drv_probe(struct device
*dev
)
337 const struct spi_driver
*sdrv
= to_spi_driver(dev
->driver
);
338 struct spi_device
*spi
= to_spi_device(dev
);
341 ret
= of_clk_set_defaults(dev
->of_node
, false);
346 spi
->irq
= of_irq_get(dev
->of_node
, 0);
347 if (spi
->irq
== -EPROBE_DEFER
)
348 return -EPROBE_DEFER
;
353 ret
= dev_pm_domain_attach(dev
, true);
354 if (ret
!= -EPROBE_DEFER
) {
355 ret
= sdrv
->probe(spi
);
357 dev_pm_domain_detach(dev
, true);
363 static int spi_drv_remove(struct device
*dev
)
365 const struct spi_driver
*sdrv
= to_spi_driver(dev
->driver
);
368 ret
= sdrv
->remove(to_spi_device(dev
));
369 dev_pm_domain_detach(dev
, true);
374 static void spi_drv_shutdown(struct device
*dev
)
376 const struct spi_driver
*sdrv
= to_spi_driver(dev
->driver
);
378 sdrv
->shutdown(to_spi_device(dev
));
382 * __spi_register_driver - register a SPI driver
383 * @owner: owner module of the driver to register
384 * @sdrv: the driver to register
387 * Return: zero on success, else a negative error code.
389 int __spi_register_driver(struct module
*owner
, struct spi_driver
*sdrv
)
391 sdrv
->driver
.owner
= owner
;
392 sdrv
->driver
.bus
= &spi_bus_type
;
394 sdrv
->driver
.probe
= spi_drv_probe
;
396 sdrv
->driver
.remove
= spi_drv_remove
;
398 sdrv
->driver
.shutdown
= spi_drv_shutdown
;
399 return driver_register(&sdrv
->driver
);
401 EXPORT_SYMBOL_GPL(__spi_register_driver
);
403 /*-------------------------------------------------------------------------*/
405 /* SPI devices should normally not be created by SPI device drivers; that
406 * would make them board-specific. Similarly with SPI master drivers.
407 * Device registration normally goes into like arch/.../mach.../board-YYY.c
408 * with other readonly (flashable) information about mainboard devices.
412 struct list_head list
;
413 struct spi_board_info board_info
;
416 static LIST_HEAD(board_list
);
417 static LIST_HEAD(spi_master_list
);
420 * Used to protect add/del opertion for board_info list and
421 * spi_master list, and their matching process
423 static DEFINE_MUTEX(board_lock
);
426 * spi_alloc_device - Allocate a new SPI device
427 * @master: Controller to which device is connected
430 * Allows a driver to allocate and initialize a spi_device without
431 * registering it immediately. This allows a driver to directly
432 * fill the spi_device with device parameters before calling
433 * spi_add_device() on it.
435 * Caller is responsible to call spi_add_device() on the returned
436 * spi_device structure to add it to the SPI master. If the caller
437 * needs to discard the spi_device without adding it, then it should
438 * call spi_dev_put() on it.
440 * Return: a pointer to the new device, or NULL.
442 struct spi_device
*spi_alloc_device(struct spi_master
*master
)
444 struct spi_device
*spi
;
446 if (!spi_master_get(master
))
449 spi
= kzalloc(sizeof(*spi
), GFP_KERNEL
);
451 spi_master_put(master
);
455 spi
->master
= master
;
456 spi
->dev
.parent
= &master
->dev
;
457 spi
->dev
.bus
= &spi_bus_type
;
458 spi
->dev
.release
= spidev_release
;
459 spi
->cs_gpio
= -ENOENT
;
461 spin_lock_init(&spi
->statistics
.lock
);
463 device_initialize(&spi
->dev
);
466 EXPORT_SYMBOL_GPL(spi_alloc_device
);
468 static void spi_dev_set_name(struct spi_device
*spi
)
470 struct acpi_device
*adev
= ACPI_COMPANION(&spi
->dev
);
473 dev_set_name(&spi
->dev
, "spi-%s", acpi_dev_name(adev
));
477 dev_set_name(&spi
->dev
, "%s.%u", dev_name(&spi
->master
->dev
),
481 static int spi_dev_check(struct device
*dev
, void *data
)
483 struct spi_device
*spi
= to_spi_device(dev
);
484 struct spi_device
*new_spi
= data
;
486 if (spi
->master
== new_spi
->master
&&
487 spi
->chip_select
== new_spi
->chip_select
)
493 * spi_add_device - Add spi_device allocated with spi_alloc_device
494 * @spi: spi_device to register
496 * Companion function to spi_alloc_device. Devices allocated with
497 * spi_alloc_device can be added onto the spi bus with this function.
499 * Return: 0 on success; negative errno on failure
501 int spi_add_device(struct spi_device
*spi
)
503 static DEFINE_MUTEX(spi_add_lock
);
504 struct spi_master
*master
= spi
->master
;
505 struct device
*dev
= master
->dev
.parent
;
508 /* Chipselects are numbered 0..max; validate. */
509 if (spi
->chip_select
>= master
->num_chipselect
) {
510 dev_err(dev
, "cs%d >= max %d\n",
512 master
->num_chipselect
);
516 /* Set the bus ID string */
517 spi_dev_set_name(spi
);
519 /* We need to make sure there's no other device with this
520 * chipselect **BEFORE** we call setup(), else we'll trash
521 * its configuration. Lock against concurrent add() calls.
523 mutex_lock(&spi_add_lock
);
525 status
= bus_for_each_dev(&spi_bus_type
, NULL
, spi
, spi_dev_check
);
527 dev_err(dev
, "chipselect %d already in use\n",
532 if (master
->cs_gpios
)
533 spi
->cs_gpio
= master
->cs_gpios
[spi
->chip_select
];
535 /* Drivers may modify this initial i/o setup, but will
536 * normally rely on the device being setup. Devices
537 * using SPI_CS_HIGH can't coexist well otherwise...
539 status
= spi_setup(spi
);
541 dev_err(dev
, "can't setup %s, status %d\n",
542 dev_name(&spi
->dev
), status
);
546 /* Device may be bound to an active driver when this returns */
547 status
= device_add(&spi
->dev
);
549 dev_err(dev
, "can't add %s, status %d\n",
550 dev_name(&spi
->dev
), status
);
552 dev_dbg(dev
, "registered child %s\n", dev_name(&spi
->dev
));
555 mutex_unlock(&spi_add_lock
);
558 EXPORT_SYMBOL_GPL(spi_add_device
);
561 * spi_new_device - instantiate one new SPI device
562 * @master: Controller to which device is connected
563 * @chip: Describes the SPI device
566 * On typical mainboards, this is purely internal; and it's not needed
567 * after board init creates the hard-wired devices. Some development
568 * platforms may not be able to use spi_register_board_info though, and
569 * this is exported so that for example a USB or parport based adapter
570 * driver could add devices (which it would learn about out-of-band).
572 * Return: the new device, or NULL.
574 struct spi_device
*spi_new_device(struct spi_master
*master
,
575 struct spi_board_info
*chip
)
577 struct spi_device
*proxy
;
580 /* NOTE: caller did any chip->bus_num checks necessary.
582 * Also, unless we change the return value convention to use
583 * error-or-pointer (not NULL-or-pointer), troubleshootability
584 * suggests syslogged diagnostics are best here (ugh).
587 proxy
= spi_alloc_device(master
);
591 WARN_ON(strlen(chip
->modalias
) >= sizeof(proxy
->modalias
));
593 proxy
->chip_select
= chip
->chip_select
;
594 proxy
->max_speed_hz
= chip
->max_speed_hz
;
595 proxy
->mode
= chip
->mode
;
596 proxy
->irq
= chip
->irq
;
597 strlcpy(proxy
->modalias
, chip
->modalias
, sizeof(proxy
->modalias
));
598 proxy
->dev
.platform_data
= (void *) chip
->platform_data
;
599 proxy
->controller_data
= chip
->controller_data
;
600 proxy
->controller_state
= NULL
;
602 status
= spi_add_device(proxy
);
610 EXPORT_SYMBOL_GPL(spi_new_device
);
613 * spi_unregister_device - unregister a single SPI device
614 * @spi: spi_device to unregister
616 * Start making the passed SPI device vanish. Normally this would be handled
617 * by spi_unregister_master().
619 void spi_unregister_device(struct spi_device
*spi
)
624 if (spi
->dev
.of_node
)
625 of_node_clear_flag(spi
->dev
.of_node
, OF_POPULATED
);
626 if (ACPI_COMPANION(&spi
->dev
))
627 acpi_device_clear_enumerated(ACPI_COMPANION(&spi
->dev
));
628 device_unregister(&spi
->dev
);
630 EXPORT_SYMBOL_GPL(spi_unregister_device
);
632 static void spi_match_master_to_boardinfo(struct spi_master
*master
,
633 struct spi_board_info
*bi
)
635 struct spi_device
*dev
;
637 if (master
->bus_num
!= bi
->bus_num
)
640 dev
= spi_new_device(master
, bi
);
642 dev_err(master
->dev
.parent
, "can't create new device for %s\n",
647 * spi_register_board_info - register SPI devices for a given board
648 * @info: array of chip descriptors
649 * @n: how many descriptors are provided
652 * Board-specific early init code calls this (probably during arch_initcall)
653 * with segments of the SPI device table. Any device nodes are created later,
654 * after the relevant parent SPI controller (bus_num) is defined. We keep
655 * this table of devices forever, so that reloading a controller driver will
656 * not make Linux forget about these hard-wired devices.
658 * Other code can also call this, e.g. a particular add-on board might provide
659 * SPI devices through its expansion connector, so code initializing that board
660 * would naturally declare its SPI devices.
662 * The board info passed can safely be __initdata ... but be careful of
663 * any embedded pointers (platform_data, etc), they're copied as-is.
665 * Return: zero on success, else a negative error code.
667 int spi_register_board_info(struct spi_board_info
const *info
, unsigned n
)
669 struct boardinfo
*bi
;
675 bi
= kzalloc(n
* sizeof(*bi
), GFP_KERNEL
);
679 for (i
= 0; i
< n
; i
++, bi
++, info
++) {
680 struct spi_master
*master
;
682 memcpy(&bi
->board_info
, info
, sizeof(*info
));
683 mutex_lock(&board_lock
);
684 list_add_tail(&bi
->list
, &board_list
);
685 list_for_each_entry(master
, &spi_master_list
, list
)
686 spi_match_master_to_boardinfo(master
, &bi
->board_info
);
687 mutex_unlock(&board_lock
);
693 /*-------------------------------------------------------------------------*/
695 static void spi_set_cs(struct spi_device
*spi
, bool enable
)
697 if (spi
->mode
& SPI_CS_HIGH
)
700 if (gpio_is_valid(spi
->cs_gpio
)) {
701 gpio_set_value(spi
->cs_gpio
, !enable
);
702 /* Some SPI masters need both GPIO CS & slave_select */
703 if ((spi
->master
->flags
& SPI_MASTER_GPIO_SS
) &&
705 spi
->master
->set_cs(spi
, !enable
);
706 } else if (spi
->master
->set_cs
) {
707 spi
->master
->set_cs(spi
, !enable
);
711 #ifdef CONFIG_HAS_DMA
712 static int spi_map_buf(struct spi_master
*master
, struct device
*dev
,
713 struct sg_table
*sgt
, void *buf
, size_t len
,
714 enum dma_data_direction dir
)
716 const bool vmalloced_buf
= is_vmalloc_addr(buf
);
717 unsigned int max_seg_size
= dma_get_max_seg_size(dev
);
718 #ifdef CONFIG_HIGHMEM
719 const bool kmap_buf
= ((unsigned long)buf
>= PKMAP_BASE
&&
720 (unsigned long)buf
< (PKMAP_BASE
+
721 (LAST_PKMAP
* PAGE_SIZE
)));
723 const bool kmap_buf
= false;
727 struct page
*vm_page
;
732 if (vmalloced_buf
|| kmap_buf
) {
733 desc_len
= min_t(int, max_seg_size
, PAGE_SIZE
);
734 sgs
= DIV_ROUND_UP(len
+ offset_in_page(buf
), desc_len
);
735 } else if (virt_addr_valid(buf
)) {
736 desc_len
= min_t(int, max_seg_size
, master
->max_dma_len
);
737 sgs
= DIV_ROUND_UP(len
, desc_len
);
742 ret
= sg_alloc_table(sgt
, sgs
, GFP_KERNEL
);
746 for (i
= 0; i
< sgs
; i
++) {
748 if (vmalloced_buf
|| kmap_buf
) {
750 len
, desc_len
- offset_in_page(buf
));
752 vm_page
= vmalloc_to_page(buf
);
754 vm_page
= kmap_to_page(buf
);
759 sg_set_page(&sgt
->sgl
[i
], vm_page
,
760 min
, offset_in_page(buf
));
762 min
= min_t(size_t, len
, desc_len
);
764 sg_set_buf(&sgt
->sgl
[i
], sg_buf
, min
);
771 ret
= dma_map_sg(dev
, sgt
->sgl
, sgt
->nents
, dir
);
784 static void spi_unmap_buf(struct spi_master
*master
, struct device
*dev
,
785 struct sg_table
*sgt
, enum dma_data_direction dir
)
787 if (sgt
->orig_nents
) {
788 dma_unmap_sg(dev
, sgt
->sgl
, sgt
->orig_nents
, dir
);
793 static int __spi_map_msg(struct spi_master
*master
, struct spi_message
*msg
)
795 struct device
*tx_dev
, *rx_dev
;
796 struct spi_transfer
*xfer
;
799 if (!master
->can_dma
)
803 tx_dev
= master
->dma_tx
->device
->dev
;
805 tx_dev
= &master
->dev
;
808 rx_dev
= master
->dma_rx
->device
->dev
;
810 rx_dev
= &master
->dev
;
812 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
813 if (!master
->can_dma(master
, msg
->spi
, xfer
))
816 if (xfer
->tx_buf
!= NULL
) {
817 ret
= spi_map_buf(master
, tx_dev
, &xfer
->tx_sg
,
818 (void *)xfer
->tx_buf
, xfer
->len
,
824 if (xfer
->rx_buf
!= NULL
) {
825 ret
= spi_map_buf(master
, rx_dev
, &xfer
->rx_sg
,
826 xfer
->rx_buf
, xfer
->len
,
829 spi_unmap_buf(master
, tx_dev
, &xfer
->tx_sg
,
836 master
->cur_msg_mapped
= true;
841 static int __spi_unmap_msg(struct spi_master
*master
, struct spi_message
*msg
)
843 struct spi_transfer
*xfer
;
844 struct device
*tx_dev
, *rx_dev
;
846 if (!master
->cur_msg_mapped
|| !master
->can_dma
)
850 tx_dev
= master
->dma_tx
->device
->dev
;
852 tx_dev
= &master
->dev
;
855 rx_dev
= master
->dma_rx
->device
->dev
;
857 rx_dev
= &master
->dev
;
859 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
860 if (!master
->can_dma(master
, msg
->spi
, xfer
))
863 spi_unmap_buf(master
, rx_dev
, &xfer
->rx_sg
, DMA_FROM_DEVICE
);
864 spi_unmap_buf(master
, tx_dev
, &xfer
->tx_sg
, DMA_TO_DEVICE
);
869 #else /* !CONFIG_HAS_DMA */
870 static inline int spi_map_buf(struct spi_master
*master
,
871 struct device
*dev
, struct sg_table
*sgt
,
872 void *buf
, size_t len
,
873 enum dma_data_direction dir
)
878 static inline void spi_unmap_buf(struct spi_master
*master
,
879 struct device
*dev
, struct sg_table
*sgt
,
880 enum dma_data_direction dir
)
884 static inline int __spi_map_msg(struct spi_master
*master
,
885 struct spi_message
*msg
)
890 static inline int __spi_unmap_msg(struct spi_master
*master
,
891 struct spi_message
*msg
)
895 #endif /* !CONFIG_HAS_DMA */
897 static inline int spi_unmap_msg(struct spi_master
*master
,
898 struct spi_message
*msg
)
900 struct spi_transfer
*xfer
;
902 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
904 * Restore the original value of tx_buf or rx_buf if they are
907 if (xfer
->tx_buf
== master
->dummy_tx
)
909 if (xfer
->rx_buf
== master
->dummy_rx
)
913 return __spi_unmap_msg(master
, msg
);
916 static int spi_map_msg(struct spi_master
*master
, struct spi_message
*msg
)
918 struct spi_transfer
*xfer
;
920 unsigned int max_tx
, max_rx
;
922 if (master
->flags
& (SPI_MASTER_MUST_RX
| SPI_MASTER_MUST_TX
)) {
926 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
927 if ((master
->flags
& SPI_MASTER_MUST_TX
) &&
929 max_tx
= max(xfer
->len
, max_tx
);
930 if ((master
->flags
& SPI_MASTER_MUST_RX
) &&
932 max_rx
= max(xfer
->len
, max_rx
);
936 tmp
= krealloc(master
->dummy_tx
, max_tx
,
937 GFP_KERNEL
| GFP_DMA
);
940 master
->dummy_tx
= tmp
;
941 memset(tmp
, 0, max_tx
);
945 tmp
= krealloc(master
->dummy_rx
, max_rx
,
946 GFP_KERNEL
| GFP_DMA
);
949 master
->dummy_rx
= tmp
;
952 if (max_tx
|| max_rx
) {
953 list_for_each_entry(xfer
, &msg
->transfers
,
956 xfer
->tx_buf
= master
->dummy_tx
;
958 xfer
->rx_buf
= master
->dummy_rx
;
963 return __spi_map_msg(master
, msg
);
967 * spi_transfer_one_message - Default implementation of transfer_one_message()
969 * This is a standard implementation of transfer_one_message() for
970 * drivers which implement a transfer_one() operation. It provides
971 * standard handling of delays and chip select management.
973 static int spi_transfer_one_message(struct spi_master
*master
,
974 struct spi_message
*msg
)
976 struct spi_transfer
*xfer
;
977 bool keep_cs
= false;
979 unsigned long long ms
= 1;
980 struct spi_statistics
*statm
= &master
->statistics
;
981 struct spi_statistics
*stats
= &msg
->spi
->statistics
;
983 spi_set_cs(msg
->spi
, true);
985 SPI_STATISTICS_INCREMENT_FIELD(statm
, messages
);
986 SPI_STATISTICS_INCREMENT_FIELD(stats
, messages
);
988 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
989 trace_spi_transfer_start(msg
, xfer
);
991 spi_statistics_add_transfer_stats(statm
, xfer
, master
);
992 spi_statistics_add_transfer_stats(stats
, xfer
, master
);
994 if (xfer
->tx_buf
|| xfer
->rx_buf
) {
995 reinit_completion(&master
->xfer_completion
);
997 ret
= master
->transfer_one(master
, msg
->spi
, xfer
);
999 SPI_STATISTICS_INCREMENT_FIELD(statm
,
1001 SPI_STATISTICS_INCREMENT_FIELD(stats
,
1003 dev_err(&msg
->spi
->dev
,
1004 "SPI transfer failed: %d\n", ret
);
1010 ms
= 8LL * 1000LL * xfer
->len
;
1011 do_div(ms
, xfer
->speed_hz
);
1012 ms
+= ms
+ 100; /* some tolerance */
1017 ms
= wait_for_completion_timeout(&master
->xfer_completion
,
1018 msecs_to_jiffies(ms
));
1022 SPI_STATISTICS_INCREMENT_FIELD(statm
,
1024 SPI_STATISTICS_INCREMENT_FIELD(stats
,
1026 dev_err(&msg
->spi
->dev
,
1027 "SPI transfer timed out\n");
1028 msg
->status
= -ETIMEDOUT
;
1032 dev_err(&msg
->spi
->dev
,
1033 "Bufferless transfer has length %u\n",
1037 trace_spi_transfer_stop(msg
, xfer
);
1039 if (msg
->status
!= -EINPROGRESS
)
1042 if (xfer
->delay_usecs
)
1043 udelay(xfer
->delay_usecs
);
1045 if (xfer
->cs_change
) {
1046 if (list_is_last(&xfer
->transfer_list
,
1050 spi_set_cs(msg
->spi
, false);
1052 spi_set_cs(msg
->spi
, true);
1056 msg
->actual_length
+= xfer
->len
;
1060 if (ret
!= 0 || !keep_cs
)
1061 spi_set_cs(msg
->spi
, false);
1063 if (msg
->status
== -EINPROGRESS
)
1066 if (msg
->status
&& master
->handle_err
)
1067 master
->handle_err(master
, msg
);
1069 spi_res_release(master
, msg
);
1071 spi_finalize_current_message(master
);
1077 * spi_finalize_current_transfer - report completion of a transfer
1078 * @master: the master reporting completion
1080 * Called by SPI drivers using the core transfer_one_message()
1081 * implementation to notify it that the current interrupt driven
1082 * transfer has finished and the next one may be scheduled.
1084 void spi_finalize_current_transfer(struct spi_master
*master
)
1086 complete(&master
->xfer_completion
);
1088 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer
);
1091 * __spi_pump_messages - function which processes spi message queue
1092 * @master: master to process queue for
1093 * @in_kthread: true if we are in the context of the message pump thread
1095 * This function checks if there is any spi message in the queue that
1096 * needs processing and if so call out to the driver to initialize hardware
1097 * and transfer each message.
1099 * Note that it is called both from the kthread itself and also from
1100 * inside spi_sync(); the queue extraction handling at the top of the
1101 * function should deal with this safely.
1103 static void __spi_pump_messages(struct spi_master
*master
, bool in_kthread
)
1105 unsigned long flags
;
1106 bool was_busy
= false;
1110 spin_lock_irqsave(&master
->queue_lock
, flags
);
1112 /* Make sure we are not already running a message */
1113 if (master
->cur_msg
) {
1114 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1118 /* If another context is idling the device then defer */
1119 if (master
->idling
) {
1120 kthread_queue_work(&master
->kworker
, &master
->pump_messages
);
1121 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1125 /* Check if the queue is idle */
1126 if (list_empty(&master
->queue
) || !master
->running
) {
1127 if (!master
->busy
) {
1128 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1132 /* Only do teardown in the thread */
1134 kthread_queue_work(&master
->kworker
,
1135 &master
->pump_messages
);
1136 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1140 master
->busy
= false;
1141 master
->idling
= true;
1142 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1144 kfree(master
->dummy_rx
);
1145 master
->dummy_rx
= NULL
;
1146 kfree(master
->dummy_tx
);
1147 master
->dummy_tx
= NULL
;
1148 if (master
->unprepare_transfer_hardware
&&
1149 master
->unprepare_transfer_hardware(master
))
1150 dev_err(&master
->dev
,
1151 "failed to unprepare transfer hardware\n");
1152 if (master
->auto_runtime_pm
) {
1153 pm_runtime_mark_last_busy(master
->dev
.parent
);
1154 pm_runtime_put_autosuspend(master
->dev
.parent
);
1156 trace_spi_master_idle(master
);
1158 spin_lock_irqsave(&master
->queue_lock
, flags
);
1159 master
->idling
= false;
1160 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1164 /* Extract head of queue */
1166 list_first_entry(&master
->queue
, struct spi_message
, queue
);
1168 list_del_init(&master
->cur_msg
->queue
);
1172 master
->busy
= true;
1173 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1175 mutex_lock(&master
->io_mutex
);
1177 if (!was_busy
&& master
->auto_runtime_pm
) {
1178 ret
= pm_runtime_get_sync(master
->dev
.parent
);
1180 dev_err(&master
->dev
, "Failed to power device: %d\n",
1182 mutex_unlock(&master
->io_mutex
);
1188 trace_spi_master_busy(master
);
1190 if (!was_busy
&& master
->prepare_transfer_hardware
) {
1191 ret
= master
->prepare_transfer_hardware(master
);
1193 dev_err(&master
->dev
,
1194 "failed to prepare transfer hardware\n");
1196 if (master
->auto_runtime_pm
)
1197 pm_runtime_put(master
->dev
.parent
);
1198 mutex_unlock(&master
->io_mutex
);
1203 trace_spi_message_start(master
->cur_msg
);
1205 if (master
->prepare_message
) {
1206 ret
= master
->prepare_message(master
, master
->cur_msg
);
1208 dev_err(&master
->dev
,
1209 "failed to prepare message: %d\n", ret
);
1210 master
->cur_msg
->status
= ret
;
1211 spi_finalize_current_message(master
);
1214 master
->cur_msg_prepared
= true;
1217 ret
= spi_map_msg(master
, master
->cur_msg
);
1219 master
->cur_msg
->status
= ret
;
1220 spi_finalize_current_message(master
);
1224 ret
= master
->transfer_one_message(master
, master
->cur_msg
);
1226 dev_err(&master
->dev
,
1227 "failed to transfer one message from queue\n");
1232 mutex_unlock(&master
->io_mutex
);
1234 /* Prod the scheduler in case transfer_one() was busy waiting */
1240 * spi_pump_messages - kthread work function which processes spi message queue
1241 * @work: pointer to kthread work struct contained in the master struct
1243 static void spi_pump_messages(struct kthread_work
*work
)
1245 struct spi_master
*master
=
1246 container_of(work
, struct spi_master
, pump_messages
);
1248 __spi_pump_messages(master
, true);
1251 static int spi_init_queue(struct spi_master
*master
)
1253 struct sched_param param
= { .sched_priority
= MAX_RT_PRIO
- 1 };
1255 master
->running
= false;
1256 master
->busy
= false;
1258 kthread_init_worker(&master
->kworker
);
1259 master
->kworker_task
= kthread_run(kthread_worker_fn
,
1260 &master
->kworker
, "%s",
1261 dev_name(&master
->dev
));
1262 if (IS_ERR(master
->kworker_task
)) {
1263 dev_err(&master
->dev
, "failed to create message pump task\n");
1264 return PTR_ERR(master
->kworker_task
);
1266 kthread_init_work(&master
->pump_messages
, spi_pump_messages
);
1269 * Master config will indicate if this controller should run the
1270 * message pump with high (realtime) priority to reduce the transfer
1271 * latency on the bus by minimising the delay between a transfer
1272 * request and the scheduling of the message pump thread. Without this
1273 * setting the message pump thread will remain at default priority.
1276 dev_info(&master
->dev
,
1277 "will run message pump with realtime priority\n");
1278 sched_setscheduler(master
->kworker_task
, SCHED_FIFO
, ¶m
);
1285 * spi_get_next_queued_message() - called by driver to check for queued
1287 * @master: the master to check for queued messages
1289 * If there are more messages in the queue, the next message is returned from
1292 * Return: the next message in the queue, else NULL if the queue is empty.
1294 struct spi_message
*spi_get_next_queued_message(struct spi_master
*master
)
1296 struct spi_message
*next
;
1297 unsigned long flags
;
1299 /* get a pointer to the next message, if any */
1300 spin_lock_irqsave(&master
->queue_lock
, flags
);
1301 next
= list_first_entry_or_null(&master
->queue
, struct spi_message
,
1303 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1307 EXPORT_SYMBOL_GPL(spi_get_next_queued_message
);
1310 * spi_finalize_current_message() - the current message is complete
1311 * @master: the master to return the message to
1313 * Called by the driver to notify the core that the message in the front of the
1314 * queue is complete and can be removed from the queue.
1316 void spi_finalize_current_message(struct spi_master
*master
)
1318 struct spi_message
*mesg
;
1319 unsigned long flags
;
1322 spin_lock_irqsave(&master
->queue_lock
, flags
);
1323 mesg
= master
->cur_msg
;
1324 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1326 spi_unmap_msg(master
, mesg
);
1328 if (master
->cur_msg_prepared
&& master
->unprepare_message
) {
1329 ret
= master
->unprepare_message(master
, mesg
);
1331 dev_err(&master
->dev
,
1332 "failed to unprepare message: %d\n", ret
);
1336 spin_lock_irqsave(&master
->queue_lock
, flags
);
1337 master
->cur_msg
= NULL
;
1338 master
->cur_msg_prepared
= false;
1339 kthread_queue_work(&master
->kworker
, &master
->pump_messages
);
1340 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1342 trace_spi_message_done(mesg
);
1346 mesg
->complete(mesg
->context
);
1348 EXPORT_SYMBOL_GPL(spi_finalize_current_message
);
1350 static int spi_start_queue(struct spi_master
*master
)
1352 unsigned long flags
;
1354 spin_lock_irqsave(&master
->queue_lock
, flags
);
1356 if (master
->running
|| master
->busy
) {
1357 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1361 master
->running
= true;
1362 master
->cur_msg
= NULL
;
1363 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1365 kthread_queue_work(&master
->kworker
, &master
->pump_messages
);
1370 static int spi_stop_queue(struct spi_master
*master
)
1372 unsigned long flags
;
1373 unsigned limit
= 500;
1376 spin_lock_irqsave(&master
->queue_lock
, flags
);
1379 * This is a bit lame, but is optimized for the common execution path.
1380 * A wait_queue on the master->busy could be used, but then the common
1381 * execution path (pump_messages) would be required to call wake_up or
1382 * friends on every SPI message. Do this instead.
1384 while ((!list_empty(&master
->queue
) || master
->busy
) && limit
--) {
1385 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1386 usleep_range(10000, 11000);
1387 spin_lock_irqsave(&master
->queue_lock
, flags
);
1390 if (!list_empty(&master
->queue
) || master
->busy
)
1393 master
->running
= false;
1395 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1398 dev_warn(&master
->dev
,
1399 "could not stop message queue\n");
1405 static int spi_destroy_queue(struct spi_master
*master
)
1409 ret
= spi_stop_queue(master
);
1412 * kthread_flush_worker will block until all work is done.
1413 * If the reason that stop_queue timed out is that the work will never
1414 * finish, then it does no good to call flush/stop thread, so
1418 dev_err(&master
->dev
, "problem destroying queue\n");
1422 kthread_flush_worker(&master
->kworker
);
1423 kthread_stop(master
->kworker_task
);
1428 static int __spi_queued_transfer(struct spi_device
*spi
,
1429 struct spi_message
*msg
,
1432 struct spi_master
*master
= spi
->master
;
1433 unsigned long flags
;
1435 spin_lock_irqsave(&master
->queue_lock
, flags
);
1437 if (!master
->running
) {
1438 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1441 msg
->actual_length
= 0;
1442 msg
->status
= -EINPROGRESS
;
1444 list_add_tail(&msg
->queue
, &master
->queue
);
1445 if (!master
->busy
&& need_pump
)
1446 kthread_queue_work(&master
->kworker
, &master
->pump_messages
);
1448 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1453 * spi_queued_transfer - transfer function for queued transfers
1454 * @spi: spi device which is requesting transfer
1455 * @msg: spi message which is to handled is queued to driver queue
1457 * Return: zero on success, else a negative error code.
1459 static int spi_queued_transfer(struct spi_device
*spi
, struct spi_message
*msg
)
1461 return __spi_queued_transfer(spi
, msg
, true);
1464 static int spi_master_initialize_queue(struct spi_master
*master
)
1468 master
->transfer
= spi_queued_transfer
;
1469 if (!master
->transfer_one_message
)
1470 master
->transfer_one_message
= spi_transfer_one_message
;
1472 /* Initialize and start queue */
1473 ret
= spi_init_queue(master
);
1475 dev_err(&master
->dev
, "problem initializing queue\n");
1476 goto err_init_queue
;
1478 master
->queued
= true;
1479 ret
= spi_start_queue(master
);
1481 dev_err(&master
->dev
, "problem starting queue\n");
1482 goto err_start_queue
;
1488 spi_destroy_queue(master
);
1493 /*-------------------------------------------------------------------------*/
1495 #if defined(CONFIG_OF)
1496 static struct spi_device
*
1497 of_register_spi_device(struct spi_master
*master
, struct device_node
*nc
)
1499 struct spi_device
*spi
;
1503 /* Alloc an spi_device */
1504 spi
= spi_alloc_device(master
);
1506 dev_err(&master
->dev
, "spi_device alloc error for %s\n",
1512 /* Select device driver */
1513 rc
= of_modalias_node(nc
, spi
->modalias
,
1514 sizeof(spi
->modalias
));
1516 dev_err(&master
->dev
, "cannot find modalias for %s\n",
1521 /* Device address */
1522 rc
= of_property_read_u32(nc
, "reg", &value
);
1524 dev_err(&master
->dev
, "%s has no valid 'reg' property (%d)\n",
1528 spi
->chip_select
= value
;
1530 /* Mode (clock phase/polarity/etc.) */
1531 if (of_find_property(nc
, "spi-cpha", NULL
))
1532 spi
->mode
|= SPI_CPHA
;
1533 if (of_find_property(nc
, "spi-cpol", NULL
))
1534 spi
->mode
|= SPI_CPOL
;
1535 if (of_find_property(nc
, "spi-cs-high", NULL
))
1536 spi
->mode
|= SPI_CS_HIGH
;
1537 if (of_find_property(nc
, "spi-3wire", NULL
))
1538 spi
->mode
|= SPI_3WIRE
;
1539 if (of_find_property(nc
, "spi-lsb-first", NULL
))
1540 spi
->mode
|= SPI_LSB_FIRST
;
1542 /* Device DUAL/QUAD mode */
1543 if (!of_property_read_u32(nc
, "spi-tx-bus-width", &value
)) {
1548 spi
->mode
|= SPI_TX_DUAL
;
1551 spi
->mode
|= SPI_TX_QUAD
;
1554 dev_warn(&master
->dev
,
1555 "spi-tx-bus-width %d not supported\n",
1561 if (!of_property_read_u32(nc
, "spi-rx-bus-width", &value
)) {
1566 spi
->mode
|= SPI_RX_DUAL
;
1569 spi
->mode
|= SPI_RX_QUAD
;
1572 dev_warn(&master
->dev
,
1573 "spi-rx-bus-width %d not supported\n",
1580 rc
= of_property_read_u32(nc
, "spi-max-frequency", &value
);
1582 dev_err(&master
->dev
, "%s has no valid 'spi-max-frequency' property (%d)\n",
1586 spi
->max_speed_hz
= value
;
1588 /* Store a pointer to the node in the device structure */
1590 spi
->dev
.of_node
= nc
;
1592 /* Register the new device */
1593 rc
= spi_add_device(spi
);
1595 dev_err(&master
->dev
, "spi_device register error %s\n",
1608 * of_register_spi_devices() - Register child devices onto the SPI bus
1609 * @master: Pointer to spi_master device
1611 * Registers an spi_device for each child node of master node which has a 'reg'
1614 static void of_register_spi_devices(struct spi_master
*master
)
1616 struct spi_device
*spi
;
1617 struct device_node
*nc
;
1619 if (!master
->dev
.of_node
)
1622 for_each_available_child_of_node(master
->dev
.of_node
, nc
) {
1623 if (of_node_test_and_set_flag(nc
, OF_POPULATED
))
1625 spi
= of_register_spi_device(master
, nc
);
1627 dev_warn(&master
->dev
, "Failed to create SPI device for %s\n",
1629 of_node_clear_flag(nc
, OF_POPULATED
);
1634 static void of_register_spi_devices(struct spi_master
*master
) { }
1638 static int acpi_spi_add_resource(struct acpi_resource
*ares
, void *data
)
1640 struct spi_device
*spi
= data
;
1641 struct spi_master
*master
= spi
->master
;
1643 if (ares
->type
== ACPI_RESOURCE_TYPE_SERIAL_BUS
) {
1644 struct acpi_resource_spi_serialbus
*sb
;
1646 sb
= &ares
->data
.spi_serial_bus
;
1647 if (sb
->type
== ACPI_RESOURCE_SERIAL_TYPE_SPI
) {
1649 * ACPI DeviceSelection numbering is handled by the
1650 * host controller driver in Windows and can vary
1651 * from driver to driver. In Linux we always expect
1652 * 0 .. max - 1 so we need to ask the driver to
1653 * translate between the two schemes.
1655 if (master
->fw_translate_cs
) {
1656 int cs
= master
->fw_translate_cs(master
,
1657 sb
->device_selection
);
1660 spi
->chip_select
= cs
;
1662 spi
->chip_select
= sb
->device_selection
;
1665 spi
->max_speed_hz
= sb
->connection_speed
;
1667 if (sb
->clock_phase
== ACPI_SPI_SECOND_PHASE
)
1668 spi
->mode
|= SPI_CPHA
;
1669 if (sb
->clock_polarity
== ACPI_SPI_START_HIGH
)
1670 spi
->mode
|= SPI_CPOL
;
1671 if (sb
->device_polarity
== ACPI_SPI_ACTIVE_HIGH
)
1672 spi
->mode
|= SPI_CS_HIGH
;
1674 } else if (spi
->irq
< 0) {
1677 if (acpi_dev_resource_interrupt(ares
, 0, &r
))
1681 /* Always tell the ACPI core to skip this resource */
1685 static acpi_status
acpi_register_spi_device(struct spi_master
*master
,
1686 struct acpi_device
*adev
)
1688 struct list_head resource_list
;
1689 struct spi_device
*spi
;
1692 if (acpi_bus_get_status(adev
) || !adev
->status
.present
||
1693 acpi_device_enumerated(adev
))
1696 spi
= spi_alloc_device(master
);
1698 dev_err(&master
->dev
, "failed to allocate SPI device for %s\n",
1699 dev_name(&adev
->dev
));
1700 return AE_NO_MEMORY
;
1703 ACPI_COMPANION_SET(&spi
->dev
, adev
);
1706 INIT_LIST_HEAD(&resource_list
);
1707 ret
= acpi_dev_get_resources(adev
, &resource_list
,
1708 acpi_spi_add_resource
, spi
);
1709 acpi_dev_free_resource_list(&resource_list
);
1711 if (ret
< 0 || !spi
->max_speed_hz
) {
1717 spi
->irq
= acpi_dev_gpio_irq_get(adev
, 0);
1719 acpi_device_set_enumerated(adev
);
1721 adev
->power
.flags
.ignore_parent
= true;
1722 strlcpy(spi
->modalias
, acpi_device_hid(adev
), sizeof(spi
->modalias
));
1723 if (spi_add_device(spi
)) {
1724 adev
->power
.flags
.ignore_parent
= false;
1725 dev_err(&master
->dev
, "failed to add SPI device %s from ACPI\n",
1726 dev_name(&adev
->dev
));
1733 static acpi_status
acpi_spi_add_device(acpi_handle handle
, u32 level
,
1734 void *data
, void **return_value
)
1736 struct spi_master
*master
= data
;
1737 struct acpi_device
*adev
;
1739 if (acpi_bus_get_device(handle
, &adev
))
1742 return acpi_register_spi_device(master
, adev
);
1745 static void acpi_register_spi_devices(struct spi_master
*master
)
1750 handle
= ACPI_HANDLE(master
->dev
.parent
);
1754 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, handle
, 1,
1755 acpi_spi_add_device
, NULL
,
1757 if (ACPI_FAILURE(status
))
1758 dev_warn(&master
->dev
, "failed to enumerate SPI slaves\n");
1761 static inline void acpi_register_spi_devices(struct spi_master
*master
) {}
1762 #endif /* CONFIG_ACPI */
1764 static void spi_master_release(struct device
*dev
)
1766 struct spi_master
*master
;
1768 master
= container_of(dev
, struct spi_master
, dev
);
1772 static struct class spi_master_class
= {
1773 .name
= "spi_master",
1774 .owner
= THIS_MODULE
,
1775 .dev_release
= spi_master_release
,
1776 .dev_groups
= spi_master_groups
,
1781 * spi_alloc_master - allocate SPI master controller
1782 * @dev: the controller, possibly using the platform_bus
1783 * @size: how much zeroed driver-private data to allocate; the pointer to this
1784 * memory is in the driver_data field of the returned device,
1785 * accessible with spi_master_get_devdata().
1786 * Context: can sleep
1788 * This call is used only by SPI master controller drivers, which are the
1789 * only ones directly touching chip registers. It's how they allocate
1790 * an spi_master structure, prior to calling spi_register_master().
1792 * This must be called from context that can sleep.
1794 * The caller is responsible for assigning the bus number and initializing
1795 * the master's methods before calling spi_register_master(); and (after errors
1796 * adding the device) calling spi_master_put() to prevent a memory leak.
1798 * Return: the SPI master structure on success, else NULL.
1800 struct spi_master
*spi_alloc_master(struct device
*dev
, unsigned size
)
1802 struct spi_master
*master
;
1807 master
= kzalloc(size
+ sizeof(*master
), GFP_KERNEL
);
1811 device_initialize(&master
->dev
);
1812 master
->bus_num
= -1;
1813 master
->num_chipselect
= 1;
1814 master
->dev
.class = &spi_master_class
;
1815 master
->dev
.parent
= dev
;
1816 pm_suspend_ignore_children(&master
->dev
, true);
1817 spi_master_set_devdata(master
, &master
[1]);
1821 EXPORT_SYMBOL_GPL(spi_alloc_master
);
1824 static int of_spi_register_master(struct spi_master
*master
)
1827 struct device_node
*np
= master
->dev
.of_node
;
1832 nb
= of_gpio_named_count(np
, "cs-gpios");
1833 master
->num_chipselect
= max_t(int, nb
, master
->num_chipselect
);
1835 /* Return error only for an incorrectly formed cs-gpios property */
1836 if (nb
== 0 || nb
== -ENOENT
)
1841 cs
= devm_kzalloc(&master
->dev
,
1842 sizeof(int) * master
->num_chipselect
,
1844 master
->cs_gpios
= cs
;
1846 if (!master
->cs_gpios
)
1849 for (i
= 0; i
< master
->num_chipselect
; i
++)
1852 for (i
= 0; i
< nb
; i
++)
1853 cs
[i
] = of_get_named_gpio(np
, "cs-gpios", i
);
1858 static int of_spi_register_master(struct spi_master
*master
)
1865 * spi_register_master - register SPI master controller
1866 * @master: initialized master, originally from spi_alloc_master()
1867 * Context: can sleep
1869 * SPI master controllers connect to their drivers using some non-SPI bus,
1870 * such as the platform bus. The final stage of probe() in that code
1871 * includes calling spi_register_master() to hook up to this SPI bus glue.
1873 * SPI controllers use board specific (often SOC specific) bus numbers,
1874 * and board-specific addressing for SPI devices combines those numbers
1875 * with chip select numbers. Since SPI does not directly support dynamic
1876 * device identification, boards need configuration tables telling which
1877 * chip is at which address.
1879 * This must be called from context that can sleep. It returns zero on
1880 * success, else a negative error code (dropping the master's refcount).
1881 * After a successful return, the caller is responsible for calling
1882 * spi_unregister_master().
1884 * Return: zero on success, else a negative error code.
1886 int spi_register_master(struct spi_master
*master
)
1888 static atomic_t dyn_bus_id
= ATOMIC_INIT((1<<15) - 1);
1889 struct device
*dev
= master
->dev
.parent
;
1890 struct boardinfo
*bi
;
1891 int status
= -ENODEV
;
1897 status
= of_spi_register_master(master
);
1901 /* even if it's just one always-selected device, there must
1902 * be at least one chipselect
1904 if (master
->num_chipselect
== 0)
1907 if ((master
->bus_num
< 0) && master
->dev
.of_node
)
1908 master
->bus_num
= of_alias_get_id(master
->dev
.of_node
, "spi");
1910 /* convention: dynamically assigned bus IDs count down from the max */
1911 if (master
->bus_num
< 0) {
1912 /* FIXME switch to an IDR based scheme, something like
1913 * I2C now uses, so we can't run out of "dynamic" IDs
1915 master
->bus_num
= atomic_dec_return(&dyn_bus_id
);
1919 INIT_LIST_HEAD(&master
->queue
);
1920 spin_lock_init(&master
->queue_lock
);
1921 spin_lock_init(&master
->bus_lock_spinlock
);
1922 mutex_init(&master
->bus_lock_mutex
);
1923 mutex_init(&master
->io_mutex
);
1924 master
->bus_lock_flag
= 0;
1925 init_completion(&master
->xfer_completion
);
1926 if (!master
->max_dma_len
)
1927 master
->max_dma_len
= INT_MAX
;
1929 /* register the device, then userspace will see it.
1930 * registration fails if the bus ID is in use.
1932 dev_set_name(&master
->dev
, "spi%u", master
->bus_num
);
1933 status
= device_add(&master
->dev
);
1936 dev_dbg(dev
, "registered master %s%s\n", dev_name(&master
->dev
),
1937 dynamic
? " (dynamic)" : "");
1939 /* If we're using a queued driver, start the queue */
1940 if (master
->transfer
)
1941 dev_info(dev
, "master is unqueued, this is deprecated\n");
1943 status
= spi_master_initialize_queue(master
);
1945 device_del(&master
->dev
);
1949 /* add statistics */
1950 spin_lock_init(&master
->statistics
.lock
);
1952 mutex_lock(&board_lock
);
1953 list_add_tail(&master
->list
, &spi_master_list
);
1954 list_for_each_entry(bi
, &board_list
, list
)
1955 spi_match_master_to_boardinfo(master
, &bi
->board_info
);
1956 mutex_unlock(&board_lock
);
1958 /* Register devices from the device tree and ACPI */
1959 of_register_spi_devices(master
);
1960 acpi_register_spi_devices(master
);
1964 EXPORT_SYMBOL_GPL(spi_register_master
);
1966 static void devm_spi_unregister(struct device
*dev
, void *res
)
1968 spi_unregister_master(*(struct spi_master
**)res
);
1972 * dev_spi_register_master - register managed SPI master controller
1973 * @dev: device managing SPI master
1974 * @master: initialized master, originally from spi_alloc_master()
1975 * Context: can sleep
1977 * Register a SPI device as with spi_register_master() which will
1978 * automatically be unregister
1980 * Return: zero on success, else a negative error code.
1982 int devm_spi_register_master(struct device
*dev
, struct spi_master
*master
)
1984 struct spi_master
**ptr
;
1987 ptr
= devres_alloc(devm_spi_unregister
, sizeof(*ptr
), GFP_KERNEL
);
1991 ret
= spi_register_master(master
);
1994 devres_add(dev
, ptr
);
2001 EXPORT_SYMBOL_GPL(devm_spi_register_master
);
2003 static int __unregister(struct device
*dev
, void *null
)
2005 spi_unregister_device(to_spi_device(dev
));
2010 * spi_unregister_master - unregister SPI master controller
2011 * @master: the master being unregistered
2012 * Context: can sleep
2014 * This call is used only by SPI master controller drivers, which are the
2015 * only ones directly touching chip registers.
2017 * This must be called from context that can sleep.
2019 void spi_unregister_master(struct spi_master
*master
)
2023 if (master
->queued
) {
2024 if (spi_destroy_queue(master
))
2025 dev_err(&master
->dev
, "queue remove failed\n");
2028 mutex_lock(&board_lock
);
2029 list_del(&master
->list
);
2030 mutex_unlock(&board_lock
);
2032 dummy
= device_for_each_child(&master
->dev
, NULL
, __unregister
);
2033 device_unregister(&master
->dev
);
2035 EXPORT_SYMBOL_GPL(spi_unregister_master
);
2037 int spi_master_suspend(struct spi_master
*master
)
2041 /* Basically no-ops for non-queued masters */
2042 if (!master
->queued
)
2045 ret
= spi_stop_queue(master
);
2047 dev_err(&master
->dev
, "queue stop failed\n");
2051 EXPORT_SYMBOL_GPL(spi_master_suspend
);
2053 int spi_master_resume(struct spi_master
*master
)
2057 if (!master
->queued
)
2060 ret
= spi_start_queue(master
);
2062 dev_err(&master
->dev
, "queue restart failed\n");
2066 EXPORT_SYMBOL_GPL(spi_master_resume
);
2068 static int __spi_master_match(struct device
*dev
, const void *data
)
2070 struct spi_master
*m
;
2071 const u16
*bus_num
= data
;
2073 m
= container_of(dev
, struct spi_master
, dev
);
2074 return m
->bus_num
== *bus_num
;
2078 * spi_busnum_to_master - look up master associated with bus_num
2079 * @bus_num: the master's bus number
2080 * Context: can sleep
2082 * This call may be used with devices that are registered after
2083 * arch init time. It returns a refcounted pointer to the relevant
2084 * spi_master (which the caller must release), or NULL if there is
2085 * no such master registered.
2087 * Return: the SPI master structure on success, else NULL.
2089 struct spi_master
*spi_busnum_to_master(u16 bus_num
)
2092 struct spi_master
*master
= NULL
;
2094 dev
= class_find_device(&spi_master_class
, NULL
, &bus_num
,
2095 __spi_master_match
);
2097 master
= container_of(dev
, struct spi_master
, dev
);
2098 /* reference got in class_find_device */
2101 EXPORT_SYMBOL_GPL(spi_busnum_to_master
);
2103 /*-------------------------------------------------------------------------*/
2105 /* Core methods for SPI resource management */
2108 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2109 * during the processing of a spi_message while using
2111 * @spi: the spi device for which we allocate memory
2112 * @release: the release code to execute for this resource
2113 * @size: size to alloc and return
2114 * @gfp: GFP allocation flags
2116 * Return: the pointer to the allocated data
2118 * This may get enhanced in the future to allocate from a memory pool
2119 * of the @spi_device or @spi_master to avoid repeated allocations.
2121 void *spi_res_alloc(struct spi_device
*spi
,
2122 spi_res_release_t release
,
2123 size_t size
, gfp_t gfp
)
2125 struct spi_res
*sres
;
2127 sres
= kzalloc(sizeof(*sres
) + size
, gfp
);
2131 INIT_LIST_HEAD(&sres
->entry
);
2132 sres
->release
= release
;
2136 EXPORT_SYMBOL_GPL(spi_res_alloc
);
2139 * spi_res_free - free an spi resource
2140 * @res: pointer to the custom data of a resource
2143 void spi_res_free(void *res
)
2145 struct spi_res
*sres
= container_of(res
, struct spi_res
, data
);
2150 WARN_ON(!list_empty(&sres
->entry
));
2153 EXPORT_SYMBOL_GPL(spi_res_free
);
2156 * spi_res_add - add a spi_res to the spi_message
2157 * @message: the spi message
2158 * @res: the spi_resource
2160 void spi_res_add(struct spi_message
*message
, void *res
)
2162 struct spi_res
*sres
= container_of(res
, struct spi_res
, data
);
2164 WARN_ON(!list_empty(&sres
->entry
));
2165 list_add_tail(&sres
->entry
, &message
->resources
);
2167 EXPORT_SYMBOL_GPL(spi_res_add
);
2170 * spi_res_release - release all spi resources for this message
2171 * @master: the @spi_master
2172 * @message: the @spi_message
2174 void spi_res_release(struct spi_master
*master
,
2175 struct spi_message
*message
)
2177 struct spi_res
*res
;
2179 while (!list_empty(&message
->resources
)) {
2180 res
= list_last_entry(&message
->resources
,
2181 struct spi_res
, entry
);
2184 res
->release(master
, message
, res
->data
);
2186 list_del(&res
->entry
);
2191 EXPORT_SYMBOL_GPL(spi_res_release
);
2193 /*-------------------------------------------------------------------------*/
2195 /* Core methods for spi_message alterations */
2197 static void __spi_replace_transfers_release(struct spi_master
*master
,
2198 struct spi_message
*msg
,
2201 struct spi_replaced_transfers
*rxfer
= res
;
2204 /* call extra callback if requested */
2206 rxfer
->release(master
, msg
, res
);
2208 /* insert replaced transfers back into the message */
2209 list_splice(&rxfer
->replaced_transfers
, rxfer
->replaced_after
);
2211 /* remove the formerly inserted entries */
2212 for (i
= 0; i
< rxfer
->inserted
; i
++)
2213 list_del(&rxfer
->inserted_transfers
[i
].transfer_list
);
2217 * spi_replace_transfers - replace transfers with several transfers
2218 * and register change with spi_message.resources
2219 * @msg: the spi_message we work upon
2220 * @xfer_first: the first spi_transfer we want to replace
2221 * @remove: number of transfers to remove
2222 * @insert: the number of transfers we want to insert instead
2223 * @release: extra release code necessary in some circumstances
2224 * @extradatasize: extra data to allocate (with alignment guarantees
2225 * of struct @spi_transfer)
2228 * Returns: pointer to @spi_replaced_transfers,
2229 * PTR_ERR(...) in case of errors.
2231 struct spi_replaced_transfers
*spi_replace_transfers(
2232 struct spi_message
*msg
,
2233 struct spi_transfer
*xfer_first
,
2236 spi_replaced_release_t release
,
2237 size_t extradatasize
,
2240 struct spi_replaced_transfers
*rxfer
;
2241 struct spi_transfer
*xfer
;
2244 /* allocate the structure using spi_res */
2245 rxfer
= spi_res_alloc(msg
->spi
, __spi_replace_transfers_release
,
2246 insert
* sizeof(struct spi_transfer
)
2247 + sizeof(struct spi_replaced_transfers
)
2251 return ERR_PTR(-ENOMEM
);
2253 /* the release code to invoke before running the generic release */
2254 rxfer
->release
= release
;
2256 /* assign extradata */
2259 &rxfer
->inserted_transfers
[insert
];
2261 /* init the replaced_transfers list */
2262 INIT_LIST_HEAD(&rxfer
->replaced_transfers
);
2264 /* assign the list_entry after which we should reinsert
2265 * the @replaced_transfers - it may be spi_message.messages!
2267 rxfer
->replaced_after
= xfer_first
->transfer_list
.prev
;
2269 /* remove the requested number of transfers */
2270 for (i
= 0; i
< remove
; i
++) {
2271 /* if the entry after replaced_after it is msg->transfers
2272 * then we have been requested to remove more transfers
2273 * than are in the list
2275 if (rxfer
->replaced_after
->next
== &msg
->transfers
) {
2276 dev_err(&msg
->spi
->dev
,
2277 "requested to remove more spi_transfers than are available\n");
2278 /* insert replaced transfers back into the message */
2279 list_splice(&rxfer
->replaced_transfers
,
2280 rxfer
->replaced_after
);
2282 /* free the spi_replace_transfer structure */
2283 spi_res_free(rxfer
);
2285 /* and return with an error */
2286 return ERR_PTR(-EINVAL
);
2289 /* remove the entry after replaced_after from list of
2290 * transfers and add it to list of replaced_transfers
2292 list_move_tail(rxfer
->replaced_after
->next
,
2293 &rxfer
->replaced_transfers
);
2296 /* create copy of the given xfer with identical settings
2297 * based on the first transfer to get removed
2299 for (i
= 0; i
< insert
; i
++) {
2300 /* we need to run in reverse order */
2301 xfer
= &rxfer
->inserted_transfers
[insert
- 1 - i
];
2303 /* copy all spi_transfer data */
2304 memcpy(xfer
, xfer_first
, sizeof(*xfer
));
2307 list_add(&xfer
->transfer_list
, rxfer
->replaced_after
);
2309 /* clear cs_change and delay_usecs for all but the last */
2311 xfer
->cs_change
= false;
2312 xfer
->delay_usecs
= 0;
2316 /* set up inserted */
2317 rxfer
->inserted
= insert
;
2319 /* and register it with spi_res/spi_message */
2320 spi_res_add(msg
, rxfer
);
2324 EXPORT_SYMBOL_GPL(spi_replace_transfers
);
2326 static int __spi_split_transfer_maxsize(struct spi_master
*master
,
2327 struct spi_message
*msg
,
2328 struct spi_transfer
**xferp
,
2332 struct spi_transfer
*xfer
= *xferp
, *xfers
;
2333 struct spi_replaced_transfers
*srt
;
2337 /* warn once about this fact that we are splitting a transfer */
2338 dev_warn_once(&msg
->spi
->dev
,
2339 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2340 xfer
->len
, maxsize
);
2342 /* calculate how many we have to replace */
2343 count
= DIV_ROUND_UP(xfer
->len
, maxsize
);
2345 /* create replacement */
2346 srt
= spi_replace_transfers(msg
, xfer
, 1, count
, NULL
, 0, gfp
);
2348 return PTR_ERR(srt
);
2349 xfers
= srt
->inserted_transfers
;
2351 /* now handle each of those newly inserted spi_transfers
2352 * note that the replacements spi_transfers all are preset
2353 * to the same values as *xferp, so tx_buf, rx_buf and len
2354 * are all identical (as well as most others)
2355 * so we just have to fix up len and the pointers.
2357 * this also includes support for the depreciated
2358 * spi_message.is_dma_mapped interface
2361 /* the first transfer just needs the length modified, so we
2362 * run it outside the loop
2364 xfers
[0].len
= min_t(size_t, maxsize
, xfer
[0].len
);
2366 /* all the others need rx_buf/tx_buf also set */
2367 for (i
= 1, offset
= maxsize
; i
< count
; offset
+= maxsize
, i
++) {
2368 /* update rx_buf, tx_buf and dma */
2369 if (xfers
[i
].rx_buf
)
2370 xfers
[i
].rx_buf
+= offset
;
2371 if (xfers
[i
].rx_dma
)
2372 xfers
[i
].rx_dma
+= offset
;
2373 if (xfers
[i
].tx_buf
)
2374 xfers
[i
].tx_buf
+= offset
;
2375 if (xfers
[i
].tx_dma
)
2376 xfers
[i
].tx_dma
+= offset
;
2379 xfers
[i
].len
= min(maxsize
, xfers
[i
].len
- offset
);
2382 /* we set up xferp to the last entry we have inserted,
2383 * so that we skip those already split transfers
2385 *xferp
= &xfers
[count
- 1];
2387 /* increment statistics counters */
2388 SPI_STATISTICS_INCREMENT_FIELD(&master
->statistics
,
2389 transfers_split_maxsize
);
2390 SPI_STATISTICS_INCREMENT_FIELD(&msg
->spi
->statistics
,
2391 transfers_split_maxsize
);
2397 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2398 * when an individual transfer exceeds a
2400 * @master: the @spi_master for this transfer
2401 * @msg: the @spi_message to transform
2402 * @maxsize: the maximum when to apply this
2403 * @gfp: GFP allocation flags
2405 * Return: status of transformation
2407 int spi_split_transfers_maxsize(struct spi_master
*master
,
2408 struct spi_message
*msg
,
2412 struct spi_transfer
*xfer
;
2415 /* iterate over the transfer_list,
2416 * but note that xfer is advanced to the last transfer inserted
2417 * to avoid checking sizes again unnecessarily (also xfer does
2418 * potentiall belong to a different list by the time the
2419 * replacement has happened
2421 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
2422 if (xfer
->len
> maxsize
) {
2423 ret
= __spi_split_transfer_maxsize(
2424 master
, msg
, &xfer
, maxsize
, gfp
);
2432 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize
);
2434 /*-------------------------------------------------------------------------*/
2436 /* Core methods for SPI master protocol drivers. Some of the
2437 * other core methods are currently defined as inline functions.
2440 static int __spi_validate_bits_per_word(struct spi_master
*master
, u8 bits_per_word
)
2442 if (master
->bits_per_word_mask
) {
2443 /* Only 32 bits fit in the mask */
2444 if (bits_per_word
> 32)
2446 if (!(master
->bits_per_word_mask
&
2447 SPI_BPW_MASK(bits_per_word
)))
2455 * spi_setup - setup SPI mode and clock rate
2456 * @spi: the device whose settings are being modified
2457 * Context: can sleep, and no requests are queued to the device
2459 * SPI protocol drivers may need to update the transfer mode if the
2460 * device doesn't work with its default. They may likewise need
2461 * to update clock rates or word sizes from initial values. This function
2462 * changes those settings, and must be called from a context that can sleep.
2463 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2464 * effect the next time the device is selected and data is transferred to
2465 * or from it. When this function returns, the spi device is deselected.
2467 * Note that this call will fail if the protocol driver specifies an option
2468 * that the underlying controller or its driver does not support. For
2469 * example, not all hardware supports wire transfers using nine bit words,
2470 * LSB-first wire encoding, or active-high chipselects.
2472 * Return: zero on success, else a negative error code.
2474 int spi_setup(struct spi_device
*spi
)
2476 unsigned bad_bits
, ugly_bits
;
2479 /* check mode to prevent that DUAL and QUAD set at the same time
2481 if (((spi
->mode
& SPI_TX_DUAL
) && (spi
->mode
& SPI_TX_QUAD
)) ||
2482 ((spi
->mode
& SPI_RX_DUAL
) && (spi
->mode
& SPI_RX_QUAD
))) {
2484 "setup: can not select dual and quad at the same time\n");
2487 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2489 if ((spi
->mode
& SPI_3WIRE
) && (spi
->mode
&
2490 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_RX_DUAL
| SPI_RX_QUAD
)))
2492 /* help drivers fail *cleanly* when they need options
2493 * that aren't supported with their current master
2495 bad_bits
= spi
->mode
& ~spi
->master
->mode_bits
;
2496 ugly_bits
= bad_bits
&
2497 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_RX_DUAL
| SPI_RX_QUAD
);
2500 "setup: ignoring unsupported mode bits %x\n",
2502 spi
->mode
&= ~ugly_bits
;
2503 bad_bits
&= ~ugly_bits
;
2506 dev_err(&spi
->dev
, "setup: unsupported mode bits %x\n",
2511 if (!spi
->bits_per_word
)
2512 spi
->bits_per_word
= 8;
2514 status
= __spi_validate_bits_per_word(spi
->master
, spi
->bits_per_word
);
2518 if (!spi
->max_speed_hz
)
2519 spi
->max_speed_hz
= spi
->master
->max_speed_hz
;
2521 if (spi
->master
->setup
)
2522 status
= spi
->master
->setup(spi
);
2524 spi_set_cs(spi
, false);
2526 dev_dbg(&spi
->dev
, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2527 (int) (spi
->mode
& (SPI_CPOL
| SPI_CPHA
)),
2528 (spi
->mode
& SPI_CS_HIGH
) ? "cs_high, " : "",
2529 (spi
->mode
& SPI_LSB_FIRST
) ? "lsb, " : "",
2530 (spi
->mode
& SPI_3WIRE
) ? "3wire, " : "",
2531 (spi
->mode
& SPI_LOOP
) ? "loopback, " : "",
2532 spi
->bits_per_word
, spi
->max_speed_hz
,
2537 EXPORT_SYMBOL_GPL(spi_setup
);
2539 static int __spi_validate(struct spi_device
*spi
, struct spi_message
*message
)
2541 struct spi_master
*master
= spi
->master
;
2542 struct spi_transfer
*xfer
;
2545 if (list_empty(&message
->transfers
))
2548 /* Half-duplex links include original MicroWire, and ones with
2549 * only one data pin like SPI_3WIRE (switches direction) or where
2550 * either MOSI or MISO is missing. They can also be caused by
2551 * software limitations.
2553 if ((master
->flags
& SPI_MASTER_HALF_DUPLEX
)
2554 || (spi
->mode
& SPI_3WIRE
)) {
2555 unsigned flags
= master
->flags
;
2557 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
2558 if (xfer
->rx_buf
&& xfer
->tx_buf
)
2560 if ((flags
& SPI_MASTER_NO_TX
) && xfer
->tx_buf
)
2562 if ((flags
& SPI_MASTER_NO_RX
) && xfer
->rx_buf
)
2568 * Set transfer bits_per_word and max speed as spi device default if
2569 * it is not set for this transfer.
2570 * Set transfer tx_nbits and rx_nbits as single transfer default
2571 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2573 message
->frame_length
= 0;
2574 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
2575 message
->frame_length
+= xfer
->len
;
2576 if (!xfer
->bits_per_word
)
2577 xfer
->bits_per_word
= spi
->bits_per_word
;
2579 if (!xfer
->speed_hz
)
2580 xfer
->speed_hz
= spi
->max_speed_hz
;
2581 if (!xfer
->speed_hz
)
2582 xfer
->speed_hz
= master
->max_speed_hz
;
2584 if (master
->max_speed_hz
&&
2585 xfer
->speed_hz
> master
->max_speed_hz
)
2586 xfer
->speed_hz
= master
->max_speed_hz
;
2588 if (__spi_validate_bits_per_word(master
, xfer
->bits_per_word
))
2592 * SPI transfer length should be multiple of SPI word size
2593 * where SPI word size should be power-of-two multiple
2595 if (xfer
->bits_per_word
<= 8)
2597 else if (xfer
->bits_per_word
<= 16)
2602 /* No partial transfers accepted */
2603 if (xfer
->len
% w_size
)
2606 if (xfer
->speed_hz
&& master
->min_speed_hz
&&
2607 xfer
->speed_hz
< master
->min_speed_hz
)
2610 if (xfer
->tx_buf
&& !xfer
->tx_nbits
)
2611 xfer
->tx_nbits
= SPI_NBITS_SINGLE
;
2612 if (xfer
->rx_buf
&& !xfer
->rx_nbits
)
2613 xfer
->rx_nbits
= SPI_NBITS_SINGLE
;
2614 /* check transfer tx/rx_nbits:
2615 * 1. check the value matches one of single, dual and quad
2616 * 2. check tx/rx_nbits match the mode in spi_device
2619 if (xfer
->tx_nbits
!= SPI_NBITS_SINGLE
&&
2620 xfer
->tx_nbits
!= SPI_NBITS_DUAL
&&
2621 xfer
->tx_nbits
!= SPI_NBITS_QUAD
)
2623 if ((xfer
->tx_nbits
== SPI_NBITS_DUAL
) &&
2624 !(spi
->mode
& (SPI_TX_DUAL
| SPI_TX_QUAD
)))
2626 if ((xfer
->tx_nbits
== SPI_NBITS_QUAD
) &&
2627 !(spi
->mode
& SPI_TX_QUAD
))
2630 /* check transfer rx_nbits */
2632 if (xfer
->rx_nbits
!= SPI_NBITS_SINGLE
&&
2633 xfer
->rx_nbits
!= SPI_NBITS_DUAL
&&
2634 xfer
->rx_nbits
!= SPI_NBITS_QUAD
)
2636 if ((xfer
->rx_nbits
== SPI_NBITS_DUAL
) &&
2637 !(spi
->mode
& (SPI_RX_DUAL
| SPI_RX_QUAD
)))
2639 if ((xfer
->rx_nbits
== SPI_NBITS_QUAD
) &&
2640 !(spi
->mode
& SPI_RX_QUAD
))
2645 message
->status
= -EINPROGRESS
;
2650 static int __spi_async(struct spi_device
*spi
, struct spi_message
*message
)
2652 struct spi_master
*master
= spi
->master
;
2656 SPI_STATISTICS_INCREMENT_FIELD(&master
->statistics
, spi_async
);
2657 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
, spi_async
);
2659 trace_spi_message_submit(message
);
2661 return master
->transfer(spi
, message
);
2665 * spi_async - asynchronous SPI transfer
2666 * @spi: device with which data will be exchanged
2667 * @message: describes the data transfers, including completion callback
2668 * Context: any (irqs may be blocked, etc)
2670 * This call may be used in_irq and other contexts which can't sleep,
2671 * as well as from task contexts which can sleep.
2673 * The completion callback is invoked in a context which can't sleep.
2674 * Before that invocation, the value of message->status is undefined.
2675 * When the callback is issued, message->status holds either zero (to
2676 * indicate complete success) or a negative error code. After that
2677 * callback returns, the driver which issued the transfer request may
2678 * deallocate the associated memory; it's no longer in use by any SPI
2679 * core or controller driver code.
2681 * Note that although all messages to a spi_device are handled in
2682 * FIFO order, messages may go to different devices in other orders.
2683 * Some device might be higher priority, or have various "hard" access
2684 * time requirements, for example.
2686 * On detection of any fault during the transfer, processing of
2687 * the entire message is aborted, and the device is deselected.
2688 * Until returning from the associated message completion callback,
2689 * no other spi_message queued to that device will be processed.
2690 * (This rule applies equally to all the synchronous transfer calls,
2691 * which are wrappers around this core asynchronous primitive.)
2693 * Return: zero on success, else a negative error code.
2695 int spi_async(struct spi_device
*spi
, struct spi_message
*message
)
2697 struct spi_master
*master
= spi
->master
;
2699 unsigned long flags
;
2701 ret
= __spi_validate(spi
, message
);
2705 spin_lock_irqsave(&master
->bus_lock_spinlock
, flags
);
2707 if (master
->bus_lock_flag
)
2710 ret
= __spi_async(spi
, message
);
2712 spin_unlock_irqrestore(&master
->bus_lock_spinlock
, flags
);
2716 EXPORT_SYMBOL_GPL(spi_async
);
2719 * spi_async_locked - version of spi_async with exclusive bus usage
2720 * @spi: device with which data will be exchanged
2721 * @message: describes the data transfers, including completion callback
2722 * Context: any (irqs may be blocked, etc)
2724 * This call may be used in_irq and other contexts which can't sleep,
2725 * as well as from task contexts which can sleep.
2727 * The completion callback is invoked in a context which can't sleep.
2728 * Before that invocation, the value of message->status is undefined.
2729 * When the callback is issued, message->status holds either zero (to
2730 * indicate complete success) or a negative error code. After that
2731 * callback returns, the driver which issued the transfer request may
2732 * deallocate the associated memory; it's no longer in use by any SPI
2733 * core or controller driver code.
2735 * Note that although all messages to a spi_device are handled in
2736 * FIFO order, messages may go to different devices in other orders.
2737 * Some device might be higher priority, or have various "hard" access
2738 * time requirements, for example.
2740 * On detection of any fault during the transfer, processing of
2741 * the entire message is aborted, and the device is deselected.
2742 * Until returning from the associated message completion callback,
2743 * no other spi_message queued to that device will be processed.
2744 * (This rule applies equally to all the synchronous transfer calls,
2745 * which are wrappers around this core asynchronous primitive.)
2747 * Return: zero on success, else a negative error code.
2749 int spi_async_locked(struct spi_device
*spi
, struct spi_message
*message
)
2751 struct spi_master
*master
= spi
->master
;
2753 unsigned long flags
;
2755 ret
= __spi_validate(spi
, message
);
2759 spin_lock_irqsave(&master
->bus_lock_spinlock
, flags
);
2761 ret
= __spi_async(spi
, message
);
2763 spin_unlock_irqrestore(&master
->bus_lock_spinlock
, flags
);
2768 EXPORT_SYMBOL_GPL(spi_async_locked
);
2771 int spi_flash_read(struct spi_device
*spi
,
2772 struct spi_flash_read_message
*msg
)
2775 struct spi_master
*master
= spi
->master
;
2776 struct device
*rx_dev
= NULL
;
2779 if ((msg
->opcode_nbits
== SPI_NBITS_DUAL
||
2780 msg
->addr_nbits
== SPI_NBITS_DUAL
) &&
2781 !(spi
->mode
& (SPI_TX_DUAL
| SPI_TX_QUAD
)))
2783 if ((msg
->opcode_nbits
== SPI_NBITS_QUAD
||
2784 msg
->addr_nbits
== SPI_NBITS_QUAD
) &&
2785 !(spi
->mode
& SPI_TX_QUAD
))
2787 if (msg
->data_nbits
== SPI_NBITS_DUAL
&&
2788 !(spi
->mode
& (SPI_RX_DUAL
| SPI_RX_QUAD
)))
2790 if (msg
->data_nbits
== SPI_NBITS_QUAD
&&
2791 !(spi
->mode
& SPI_RX_QUAD
))
2794 if (master
->auto_runtime_pm
) {
2795 ret
= pm_runtime_get_sync(master
->dev
.parent
);
2797 dev_err(&master
->dev
, "Failed to power device: %d\n",
2803 mutex_lock(&master
->bus_lock_mutex
);
2804 mutex_lock(&master
->io_mutex
);
2805 if (master
->dma_rx
) {
2806 rx_dev
= master
->dma_rx
->device
->dev
;
2807 ret
= spi_map_buf(master
, rx_dev
, &msg
->rx_sg
,
2811 msg
->cur_msg_mapped
= true;
2813 ret
= master
->spi_flash_read(spi
, msg
);
2814 if (msg
->cur_msg_mapped
)
2815 spi_unmap_buf(master
, rx_dev
, &msg
->rx_sg
,
2817 mutex_unlock(&master
->io_mutex
);
2818 mutex_unlock(&master
->bus_lock_mutex
);
2820 if (master
->auto_runtime_pm
)
2821 pm_runtime_put(master
->dev
.parent
);
2825 EXPORT_SYMBOL_GPL(spi_flash_read
);
2827 /*-------------------------------------------------------------------------*/
2829 /* Utility methods for SPI master protocol drivers, layered on
2830 * top of the core. Some other utility methods are defined as
2834 static void spi_complete(void *arg
)
2839 static int __spi_sync(struct spi_device
*spi
, struct spi_message
*message
)
2841 DECLARE_COMPLETION_ONSTACK(done
);
2843 struct spi_master
*master
= spi
->master
;
2844 unsigned long flags
;
2846 status
= __spi_validate(spi
, message
);
2850 message
->complete
= spi_complete
;
2851 message
->context
= &done
;
2854 SPI_STATISTICS_INCREMENT_FIELD(&master
->statistics
, spi_sync
);
2855 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
, spi_sync
);
2857 /* If we're not using the legacy transfer method then we will
2858 * try to transfer in the calling context so special case.
2859 * This code would be less tricky if we could remove the
2860 * support for driver implemented message queues.
2862 if (master
->transfer
== spi_queued_transfer
) {
2863 spin_lock_irqsave(&master
->bus_lock_spinlock
, flags
);
2865 trace_spi_message_submit(message
);
2867 status
= __spi_queued_transfer(spi
, message
, false);
2869 spin_unlock_irqrestore(&master
->bus_lock_spinlock
, flags
);
2871 status
= spi_async_locked(spi
, message
);
2875 /* Push out the messages in the calling context if we
2878 if (master
->transfer
== spi_queued_transfer
) {
2879 SPI_STATISTICS_INCREMENT_FIELD(&master
->statistics
,
2880 spi_sync_immediate
);
2881 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
,
2882 spi_sync_immediate
);
2883 __spi_pump_messages(master
, false);
2886 wait_for_completion(&done
);
2887 status
= message
->status
;
2889 message
->context
= NULL
;
2894 * spi_sync - blocking/synchronous SPI data transfers
2895 * @spi: device with which data will be exchanged
2896 * @message: describes the data transfers
2897 * Context: can sleep
2899 * This call may only be used from a context that may sleep. The sleep
2900 * is non-interruptible, and has no timeout. Low-overhead controller
2901 * drivers may DMA directly into and out of the message buffers.
2903 * Note that the SPI device's chip select is active during the message,
2904 * and then is normally disabled between messages. Drivers for some
2905 * frequently-used devices may want to minimize costs of selecting a chip,
2906 * by leaving it selected in anticipation that the next message will go
2907 * to the same chip. (That may increase power usage.)
2909 * Also, the caller is guaranteeing that the memory associated with the
2910 * message will not be freed before this call returns.
2912 * Return: zero on success, else a negative error code.
2914 int spi_sync(struct spi_device
*spi
, struct spi_message
*message
)
2918 mutex_lock(&spi
->master
->bus_lock_mutex
);
2919 ret
= __spi_sync(spi
, message
);
2920 mutex_unlock(&spi
->master
->bus_lock_mutex
);
2924 EXPORT_SYMBOL_GPL(spi_sync
);
2927 * spi_sync_locked - version of spi_sync with exclusive bus usage
2928 * @spi: device with which data will be exchanged
2929 * @message: describes the data transfers
2930 * Context: can sleep
2932 * This call may only be used from a context that may sleep. The sleep
2933 * is non-interruptible, and has no timeout. Low-overhead controller
2934 * drivers may DMA directly into and out of the message buffers.
2936 * This call should be used by drivers that require exclusive access to the
2937 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
2938 * be released by a spi_bus_unlock call when the exclusive access is over.
2940 * Return: zero on success, else a negative error code.
2942 int spi_sync_locked(struct spi_device
*spi
, struct spi_message
*message
)
2944 return __spi_sync(spi
, message
);
2946 EXPORT_SYMBOL_GPL(spi_sync_locked
);
2949 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2950 * @master: SPI bus master that should be locked for exclusive bus access
2951 * Context: can sleep
2953 * This call may only be used from a context that may sleep. The sleep
2954 * is non-interruptible, and has no timeout.
2956 * This call should be used by drivers that require exclusive access to the
2957 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2958 * exclusive access is over. Data transfer must be done by spi_sync_locked
2959 * and spi_async_locked calls when the SPI bus lock is held.
2961 * Return: always zero.
2963 int spi_bus_lock(struct spi_master
*master
)
2965 unsigned long flags
;
2967 mutex_lock(&master
->bus_lock_mutex
);
2969 spin_lock_irqsave(&master
->bus_lock_spinlock
, flags
);
2970 master
->bus_lock_flag
= 1;
2971 spin_unlock_irqrestore(&master
->bus_lock_spinlock
, flags
);
2973 /* mutex remains locked until spi_bus_unlock is called */
2977 EXPORT_SYMBOL_GPL(spi_bus_lock
);
2980 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2981 * @master: SPI bus master that was locked for exclusive bus access
2982 * Context: can sleep
2984 * This call may only be used from a context that may sleep. The sleep
2985 * is non-interruptible, and has no timeout.
2987 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2990 * Return: always zero.
2992 int spi_bus_unlock(struct spi_master
*master
)
2994 master
->bus_lock_flag
= 0;
2996 mutex_unlock(&master
->bus_lock_mutex
);
3000 EXPORT_SYMBOL_GPL(spi_bus_unlock
);
3002 /* portable code must never pass more than 32 bytes */
3003 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3008 * spi_write_then_read - SPI synchronous write followed by read
3009 * @spi: device with which data will be exchanged
3010 * @txbuf: data to be written (need not be dma-safe)
3011 * @n_tx: size of txbuf, in bytes
3012 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3013 * @n_rx: size of rxbuf, in bytes
3014 * Context: can sleep
3016 * This performs a half duplex MicroWire style transaction with the
3017 * device, sending txbuf and then reading rxbuf. The return value
3018 * is zero for success, else a negative errno status code.
3019 * This call may only be used from a context that may sleep.
3021 * Parameters to this routine are always copied using a small buffer;
3022 * portable code should never use this for more than 32 bytes.
3023 * Performance-sensitive or bulk transfer code should instead use
3024 * spi_{async,sync}() calls with dma-safe buffers.
3026 * Return: zero on success, else a negative error code.
3028 int spi_write_then_read(struct spi_device
*spi
,
3029 const void *txbuf
, unsigned n_tx
,
3030 void *rxbuf
, unsigned n_rx
)
3032 static DEFINE_MUTEX(lock
);
3035 struct spi_message message
;
3036 struct spi_transfer x
[2];
3039 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3040 * copying here, (as a pure convenience thing), but we can
3041 * keep heap costs out of the hot path unless someone else is
3042 * using the pre-allocated buffer or the transfer is too large.
3044 if ((n_tx
+ n_rx
) > SPI_BUFSIZ
|| !mutex_trylock(&lock
)) {
3045 local_buf
= kmalloc(max((unsigned)SPI_BUFSIZ
, n_tx
+ n_rx
),
3046 GFP_KERNEL
| GFP_DMA
);
3053 spi_message_init(&message
);
3054 memset(x
, 0, sizeof(x
));
3057 spi_message_add_tail(&x
[0], &message
);
3061 spi_message_add_tail(&x
[1], &message
);
3064 memcpy(local_buf
, txbuf
, n_tx
);
3065 x
[0].tx_buf
= local_buf
;
3066 x
[1].rx_buf
= local_buf
+ n_tx
;
3069 status
= spi_sync(spi
, &message
);
3071 memcpy(rxbuf
, x
[1].rx_buf
, n_rx
);
3073 if (x
[0].tx_buf
== buf
)
3074 mutex_unlock(&lock
);
3080 EXPORT_SYMBOL_GPL(spi_write_then_read
);
3082 /*-------------------------------------------------------------------------*/
3084 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
3085 static int __spi_of_device_match(struct device
*dev
, void *data
)
3087 return dev
->of_node
== data
;
3090 /* must call put_device() when done with returned spi_device device */
3091 static struct spi_device
*of_find_spi_device_by_node(struct device_node
*node
)
3093 struct device
*dev
= bus_find_device(&spi_bus_type
, NULL
, node
,
3094 __spi_of_device_match
);
3095 return dev
? to_spi_device(dev
) : NULL
;
3098 static int __spi_of_master_match(struct device
*dev
, const void *data
)
3100 return dev
->of_node
== data
;
3103 /* the spi masters are not using spi_bus, so we find it with another way */
3104 static struct spi_master
*of_find_spi_master_by_node(struct device_node
*node
)
3108 dev
= class_find_device(&spi_master_class
, NULL
, node
,
3109 __spi_of_master_match
);
3113 /* reference got in class_find_device */
3114 return container_of(dev
, struct spi_master
, dev
);
3117 static int of_spi_notify(struct notifier_block
*nb
, unsigned long action
,
3120 struct of_reconfig_data
*rd
= arg
;
3121 struct spi_master
*master
;
3122 struct spi_device
*spi
;
3124 switch (of_reconfig_get_state_change(action
, arg
)) {
3125 case OF_RECONFIG_CHANGE_ADD
:
3126 master
= of_find_spi_master_by_node(rd
->dn
->parent
);
3128 return NOTIFY_OK
; /* not for us */
3130 if (of_node_test_and_set_flag(rd
->dn
, OF_POPULATED
)) {
3131 put_device(&master
->dev
);
3135 spi
= of_register_spi_device(master
, rd
->dn
);
3136 put_device(&master
->dev
);
3139 pr_err("%s: failed to create for '%s'\n",
3140 __func__
, rd
->dn
->full_name
);
3141 of_node_clear_flag(rd
->dn
, OF_POPULATED
);
3142 return notifier_from_errno(PTR_ERR(spi
));
3146 case OF_RECONFIG_CHANGE_REMOVE
:
3147 /* already depopulated? */
3148 if (!of_node_check_flag(rd
->dn
, OF_POPULATED
))
3151 /* find our device by node */
3152 spi
= of_find_spi_device_by_node(rd
->dn
);
3154 return NOTIFY_OK
; /* no? not meant for us */
3156 /* unregister takes one ref away */
3157 spi_unregister_device(spi
);
3159 /* and put the reference of the find */
3160 put_device(&spi
->dev
);
3167 static struct notifier_block spi_of_notifier
= {
3168 .notifier_call
= of_spi_notify
,
3170 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3171 extern struct notifier_block spi_of_notifier
;
3172 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3174 #if IS_ENABLED(CONFIG_ACPI)
3175 static int spi_acpi_master_match(struct device
*dev
, const void *data
)
3177 return ACPI_COMPANION(dev
->parent
) == data
;
3180 static int spi_acpi_device_match(struct device
*dev
, void *data
)
3182 return ACPI_COMPANION(dev
) == data
;
3185 static struct spi_master
*acpi_spi_find_master_by_adev(struct acpi_device
*adev
)
3189 dev
= class_find_device(&spi_master_class
, NULL
, adev
,
3190 spi_acpi_master_match
);
3194 return container_of(dev
, struct spi_master
, dev
);
3197 static struct spi_device
*acpi_spi_find_device_by_adev(struct acpi_device
*adev
)
3201 dev
= bus_find_device(&spi_bus_type
, NULL
, adev
, spi_acpi_device_match
);
3203 return dev
? to_spi_device(dev
) : NULL
;
3206 static int acpi_spi_notify(struct notifier_block
*nb
, unsigned long value
,
3209 struct acpi_device
*adev
= arg
;
3210 struct spi_master
*master
;
3211 struct spi_device
*spi
;
3214 case ACPI_RECONFIG_DEVICE_ADD
:
3215 master
= acpi_spi_find_master_by_adev(adev
->parent
);
3219 acpi_register_spi_device(master
, adev
);
3220 put_device(&master
->dev
);
3222 case ACPI_RECONFIG_DEVICE_REMOVE
:
3223 if (!acpi_device_enumerated(adev
))
3226 spi
= acpi_spi_find_device_by_adev(adev
);
3230 spi_unregister_device(spi
);
3231 put_device(&spi
->dev
);
3238 static struct notifier_block spi_acpi_notifier
= {
3239 .notifier_call
= acpi_spi_notify
,
3242 extern struct notifier_block spi_acpi_notifier
;
3245 static int __init
spi_init(void)
3249 buf
= kmalloc(SPI_BUFSIZ
, GFP_KERNEL
);
3255 status
= bus_register(&spi_bus_type
);
3259 status
= class_register(&spi_master_class
);
3263 if (IS_ENABLED(CONFIG_OF_DYNAMIC
))
3264 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier
));
3265 if (IS_ENABLED(CONFIG_ACPI
))
3266 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier
));
3271 bus_unregister(&spi_bus_type
);
3279 /* board_info is normally registered in arch_initcall(),
3280 * but even essential drivers wait till later
3282 * REVISIT only boardinfo really needs static linking. the rest (device and
3283 * driver registration) _could_ be dynamically linked (modular) ... costs
3284 * include needing to have boardinfo data structures be much more public.
3286 postcore_initcall(spi_init
);