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
;
728 struct scatterlist
*sg
;
733 if (vmalloced_buf
|| kmap_buf
) {
734 desc_len
= min_t(int, max_seg_size
, PAGE_SIZE
);
735 sgs
= DIV_ROUND_UP(len
+ offset_in_page(buf
), desc_len
);
736 } else if (virt_addr_valid(buf
)) {
737 desc_len
= min_t(int, max_seg_size
, master
->max_dma_len
);
738 sgs
= DIV_ROUND_UP(len
, desc_len
);
743 ret
= sg_alloc_table(sgt
, sgs
, GFP_KERNEL
);
748 for (i
= 0; i
< sgs
; i
++) {
750 if (vmalloced_buf
|| kmap_buf
) {
752 len
, desc_len
- offset_in_page(buf
));
754 vm_page
= vmalloc_to_page(buf
);
756 vm_page
= kmap_to_page(buf
);
761 sg_set_page(sg
, vm_page
,
762 min
, offset_in_page(buf
));
764 min
= min_t(size_t, len
, desc_len
);
766 sg_set_buf(sg
, sg_buf
, min
);
774 ret
= dma_map_sg(dev
, sgt
->sgl
, sgt
->nents
, dir
);
787 static void spi_unmap_buf(struct spi_master
*master
, struct device
*dev
,
788 struct sg_table
*sgt
, enum dma_data_direction dir
)
790 if (sgt
->orig_nents
) {
791 dma_unmap_sg(dev
, sgt
->sgl
, sgt
->orig_nents
, dir
);
796 static int __spi_map_msg(struct spi_master
*master
, struct spi_message
*msg
)
798 struct device
*tx_dev
, *rx_dev
;
799 struct spi_transfer
*xfer
;
802 if (!master
->can_dma
)
806 tx_dev
= master
->dma_tx
->device
->dev
;
808 tx_dev
= &master
->dev
;
811 rx_dev
= master
->dma_rx
->device
->dev
;
813 rx_dev
= &master
->dev
;
815 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
816 if (!master
->can_dma(master
, msg
->spi
, xfer
))
819 if (xfer
->tx_buf
!= NULL
) {
820 ret
= spi_map_buf(master
, tx_dev
, &xfer
->tx_sg
,
821 (void *)xfer
->tx_buf
, xfer
->len
,
827 if (xfer
->rx_buf
!= NULL
) {
828 ret
= spi_map_buf(master
, rx_dev
, &xfer
->rx_sg
,
829 xfer
->rx_buf
, xfer
->len
,
832 spi_unmap_buf(master
, tx_dev
, &xfer
->tx_sg
,
839 master
->cur_msg_mapped
= true;
844 static int __spi_unmap_msg(struct spi_master
*master
, struct spi_message
*msg
)
846 struct spi_transfer
*xfer
;
847 struct device
*tx_dev
, *rx_dev
;
849 if (!master
->cur_msg_mapped
|| !master
->can_dma
)
853 tx_dev
= master
->dma_tx
->device
->dev
;
855 tx_dev
= &master
->dev
;
858 rx_dev
= master
->dma_rx
->device
->dev
;
860 rx_dev
= &master
->dev
;
862 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
863 if (!master
->can_dma(master
, msg
->spi
, xfer
))
866 spi_unmap_buf(master
, rx_dev
, &xfer
->rx_sg
, DMA_FROM_DEVICE
);
867 spi_unmap_buf(master
, tx_dev
, &xfer
->tx_sg
, DMA_TO_DEVICE
);
872 #else /* !CONFIG_HAS_DMA */
873 static inline int spi_map_buf(struct spi_master
*master
,
874 struct device
*dev
, struct sg_table
*sgt
,
875 void *buf
, size_t len
,
876 enum dma_data_direction dir
)
881 static inline void spi_unmap_buf(struct spi_master
*master
,
882 struct device
*dev
, struct sg_table
*sgt
,
883 enum dma_data_direction dir
)
887 static inline int __spi_map_msg(struct spi_master
*master
,
888 struct spi_message
*msg
)
893 static inline int __spi_unmap_msg(struct spi_master
*master
,
894 struct spi_message
*msg
)
898 #endif /* !CONFIG_HAS_DMA */
900 static inline int spi_unmap_msg(struct spi_master
*master
,
901 struct spi_message
*msg
)
903 struct spi_transfer
*xfer
;
905 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
907 * Restore the original value of tx_buf or rx_buf if they are
910 if (xfer
->tx_buf
== master
->dummy_tx
)
912 if (xfer
->rx_buf
== master
->dummy_rx
)
916 return __spi_unmap_msg(master
, msg
);
919 static int spi_map_msg(struct spi_master
*master
, struct spi_message
*msg
)
921 struct spi_transfer
*xfer
;
923 unsigned int max_tx
, max_rx
;
925 if (master
->flags
& (SPI_MASTER_MUST_RX
| SPI_MASTER_MUST_TX
)) {
929 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
930 if ((master
->flags
& SPI_MASTER_MUST_TX
) &&
932 max_tx
= max(xfer
->len
, max_tx
);
933 if ((master
->flags
& SPI_MASTER_MUST_RX
) &&
935 max_rx
= max(xfer
->len
, max_rx
);
939 tmp
= krealloc(master
->dummy_tx
, max_tx
,
940 GFP_KERNEL
| GFP_DMA
);
943 master
->dummy_tx
= tmp
;
944 memset(tmp
, 0, max_tx
);
948 tmp
= krealloc(master
->dummy_rx
, max_rx
,
949 GFP_KERNEL
| GFP_DMA
);
952 master
->dummy_rx
= tmp
;
955 if (max_tx
|| max_rx
) {
956 list_for_each_entry(xfer
, &msg
->transfers
,
959 xfer
->tx_buf
= master
->dummy_tx
;
961 xfer
->rx_buf
= master
->dummy_rx
;
966 return __spi_map_msg(master
, msg
);
970 * spi_transfer_one_message - Default implementation of transfer_one_message()
972 * This is a standard implementation of transfer_one_message() for
973 * drivers which implement a transfer_one() operation. It provides
974 * standard handling of delays and chip select management.
976 static int spi_transfer_one_message(struct spi_master
*master
,
977 struct spi_message
*msg
)
979 struct spi_transfer
*xfer
;
980 bool keep_cs
= false;
982 unsigned long long ms
= 1;
983 struct spi_statistics
*statm
= &master
->statistics
;
984 struct spi_statistics
*stats
= &msg
->spi
->statistics
;
986 spi_set_cs(msg
->spi
, true);
988 SPI_STATISTICS_INCREMENT_FIELD(statm
, messages
);
989 SPI_STATISTICS_INCREMENT_FIELD(stats
, messages
);
991 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
992 trace_spi_transfer_start(msg
, xfer
);
994 spi_statistics_add_transfer_stats(statm
, xfer
, master
);
995 spi_statistics_add_transfer_stats(stats
, xfer
, master
);
997 if (xfer
->tx_buf
|| xfer
->rx_buf
) {
998 reinit_completion(&master
->xfer_completion
);
1000 ret
= master
->transfer_one(master
, msg
->spi
, xfer
);
1002 SPI_STATISTICS_INCREMENT_FIELD(statm
,
1004 SPI_STATISTICS_INCREMENT_FIELD(stats
,
1006 dev_err(&msg
->spi
->dev
,
1007 "SPI transfer failed: %d\n", ret
);
1013 ms
= 8LL * 1000LL * xfer
->len
;
1014 do_div(ms
, xfer
->speed_hz
);
1015 ms
+= ms
+ 100; /* some tolerance */
1020 ms
= wait_for_completion_timeout(&master
->xfer_completion
,
1021 msecs_to_jiffies(ms
));
1025 SPI_STATISTICS_INCREMENT_FIELD(statm
,
1027 SPI_STATISTICS_INCREMENT_FIELD(stats
,
1029 dev_err(&msg
->spi
->dev
,
1030 "SPI transfer timed out\n");
1031 msg
->status
= -ETIMEDOUT
;
1035 dev_err(&msg
->spi
->dev
,
1036 "Bufferless transfer has length %u\n",
1040 trace_spi_transfer_stop(msg
, xfer
);
1042 if (msg
->status
!= -EINPROGRESS
)
1045 if (xfer
->delay_usecs
) {
1046 u16 us
= xfer
->delay_usecs
;
1051 usleep_range(us
, us
+ DIV_ROUND_UP(us
, 10));
1054 if (xfer
->cs_change
) {
1055 if (list_is_last(&xfer
->transfer_list
,
1059 spi_set_cs(msg
->spi
, false);
1061 spi_set_cs(msg
->spi
, true);
1065 msg
->actual_length
+= xfer
->len
;
1069 if (ret
!= 0 || !keep_cs
)
1070 spi_set_cs(msg
->spi
, false);
1072 if (msg
->status
== -EINPROGRESS
)
1075 if (msg
->status
&& master
->handle_err
)
1076 master
->handle_err(master
, msg
);
1078 spi_res_release(master
, msg
);
1080 spi_finalize_current_message(master
);
1086 * spi_finalize_current_transfer - report completion of a transfer
1087 * @master: the master reporting completion
1089 * Called by SPI drivers using the core transfer_one_message()
1090 * implementation to notify it that the current interrupt driven
1091 * transfer has finished and the next one may be scheduled.
1093 void spi_finalize_current_transfer(struct spi_master
*master
)
1095 complete(&master
->xfer_completion
);
1097 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer
);
1100 * __spi_pump_messages - function which processes spi message queue
1101 * @master: master to process queue for
1102 * @in_kthread: true if we are in the context of the message pump thread
1104 * This function checks if there is any spi message in the queue that
1105 * needs processing and if so call out to the driver to initialize hardware
1106 * and transfer each message.
1108 * Note that it is called both from the kthread itself and also from
1109 * inside spi_sync(); the queue extraction handling at the top of the
1110 * function should deal with this safely.
1112 static void __spi_pump_messages(struct spi_master
*master
, bool in_kthread
)
1114 unsigned long flags
;
1115 bool was_busy
= false;
1119 spin_lock_irqsave(&master
->queue_lock
, flags
);
1121 /* Make sure we are not already running a message */
1122 if (master
->cur_msg
) {
1123 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1127 /* If another context is idling the device then defer */
1128 if (master
->idling
) {
1129 kthread_queue_work(&master
->kworker
, &master
->pump_messages
);
1130 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1134 /* Check if the queue is idle */
1135 if (list_empty(&master
->queue
) || !master
->running
) {
1136 if (!master
->busy
) {
1137 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1141 /* Only do teardown in the thread */
1143 kthread_queue_work(&master
->kworker
,
1144 &master
->pump_messages
);
1145 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1149 master
->busy
= false;
1150 master
->idling
= true;
1151 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1153 kfree(master
->dummy_rx
);
1154 master
->dummy_rx
= NULL
;
1155 kfree(master
->dummy_tx
);
1156 master
->dummy_tx
= NULL
;
1157 if (master
->unprepare_transfer_hardware
&&
1158 master
->unprepare_transfer_hardware(master
))
1159 dev_err(&master
->dev
,
1160 "failed to unprepare transfer hardware\n");
1161 if (master
->auto_runtime_pm
) {
1162 pm_runtime_mark_last_busy(master
->dev
.parent
);
1163 pm_runtime_put_autosuspend(master
->dev
.parent
);
1165 trace_spi_master_idle(master
);
1167 spin_lock_irqsave(&master
->queue_lock
, flags
);
1168 master
->idling
= false;
1169 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1173 /* Extract head of queue */
1175 list_first_entry(&master
->queue
, struct spi_message
, queue
);
1177 list_del_init(&master
->cur_msg
->queue
);
1181 master
->busy
= true;
1182 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1184 mutex_lock(&master
->io_mutex
);
1186 if (!was_busy
&& master
->auto_runtime_pm
) {
1187 ret
= pm_runtime_get_sync(master
->dev
.parent
);
1189 dev_err(&master
->dev
, "Failed to power device: %d\n",
1191 mutex_unlock(&master
->io_mutex
);
1197 trace_spi_master_busy(master
);
1199 if (!was_busy
&& master
->prepare_transfer_hardware
) {
1200 ret
= master
->prepare_transfer_hardware(master
);
1202 dev_err(&master
->dev
,
1203 "failed to prepare transfer hardware\n");
1205 if (master
->auto_runtime_pm
)
1206 pm_runtime_put(master
->dev
.parent
);
1207 mutex_unlock(&master
->io_mutex
);
1212 trace_spi_message_start(master
->cur_msg
);
1214 if (master
->prepare_message
) {
1215 ret
= master
->prepare_message(master
, master
->cur_msg
);
1217 dev_err(&master
->dev
,
1218 "failed to prepare message: %d\n", ret
);
1219 master
->cur_msg
->status
= ret
;
1220 spi_finalize_current_message(master
);
1223 master
->cur_msg_prepared
= true;
1226 ret
= spi_map_msg(master
, master
->cur_msg
);
1228 master
->cur_msg
->status
= ret
;
1229 spi_finalize_current_message(master
);
1233 ret
= master
->transfer_one_message(master
, master
->cur_msg
);
1235 dev_err(&master
->dev
,
1236 "failed to transfer one message from queue\n");
1241 mutex_unlock(&master
->io_mutex
);
1243 /* Prod the scheduler in case transfer_one() was busy waiting */
1249 * spi_pump_messages - kthread work function which processes spi message queue
1250 * @work: pointer to kthread work struct contained in the master struct
1252 static void spi_pump_messages(struct kthread_work
*work
)
1254 struct spi_master
*master
=
1255 container_of(work
, struct spi_master
, pump_messages
);
1257 __spi_pump_messages(master
, true);
1260 static int spi_init_queue(struct spi_master
*master
)
1262 struct sched_param param
= { .sched_priority
= MAX_RT_PRIO
- 1 };
1264 master
->running
= false;
1265 master
->busy
= false;
1267 kthread_init_worker(&master
->kworker
);
1268 master
->kworker_task
= kthread_run(kthread_worker_fn
,
1269 &master
->kworker
, "%s",
1270 dev_name(&master
->dev
));
1271 if (IS_ERR(master
->kworker_task
)) {
1272 dev_err(&master
->dev
, "failed to create message pump task\n");
1273 return PTR_ERR(master
->kworker_task
);
1275 kthread_init_work(&master
->pump_messages
, spi_pump_messages
);
1278 * Master config will indicate if this controller should run the
1279 * message pump with high (realtime) priority to reduce the transfer
1280 * latency on the bus by minimising the delay between a transfer
1281 * request and the scheduling of the message pump thread. Without this
1282 * setting the message pump thread will remain at default priority.
1285 dev_info(&master
->dev
,
1286 "will run message pump with realtime priority\n");
1287 sched_setscheduler(master
->kworker_task
, SCHED_FIFO
, ¶m
);
1294 * spi_get_next_queued_message() - called by driver to check for queued
1296 * @master: the master to check for queued messages
1298 * If there are more messages in the queue, the next message is returned from
1301 * Return: the next message in the queue, else NULL if the queue is empty.
1303 struct spi_message
*spi_get_next_queued_message(struct spi_master
*master
)
1305 struct spi_message
*next
;
1306 unsigned long flags
;
1308 /* get a pointer to the next message, if any */
1309 spin_lock_irqsave(&master
->queue_lock
, flags
);
1310 next
= list_first_entry_or_null(&master
->queue
, struct spi_message
,
1312 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1316 EXPORT_SYMBOL_GPL(spi_get_next_queued_message
);
1319 * spi_finalize_current_message() - the current message is complete
1320 * @master: the master to return the message to
1322 * Called by the driver to notify the core that the message in the front of the
1323 * queue is complete and can be removed from the queue.
1325 void spi_finalize_current_message(struct spi_master
*master
)
1327 struct spi_message
*mesg
;
1328 unsigned long flags
;
1331 spin_lock_irqsave(&master
->queue_lock
, flags
);
1332 mesg
= master
->cur_msg
;
1333 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1335 spi_unmap_msg(master
, mesg
);
1337 if (master
->cur_msg_prepared
&& master
->unprepare_message
) {
1338 ret
= master
->unprepare_message(master
, mesg
);
1340 dev_err(&master
->dev
,
1341 "failed to unprepare message: %d\n", ret
);
1345 spin_lock_irqsave(&master
->queue_lock
, flags
);
1346 master
->cur_msg
= NULL
;
1347 master
->cur_msg_prepared
= false;
1348 kthread_queue_work(&master
->kworker
, &master
->pump_messages
);
1349 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1351 trace_spi_message_done(mesg
);
1355 mesg
->complete(mesg
->context
);
1357 EXPORT_SYMBOL_GPL(spi_finalize_current_message
);
1359 static int spi_start_queue(struct spi_master
*master
)
1361 unsigned long flags
;
1363 spin_lock_irqsave(&master
->queue_lock
, flags
);
1365 if (master
->running
|| master
->busy
) {
1366 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1370 master
->running
= true;
1371 master
->cur_msg
= NULL
;
1372 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1374 kthread_queue_work(&master
->kworker
, &master
->pump_messages
);
1379 static int spi_stop_queue(struct spi_master
*master
)
1381 unsigned long flags
;
1382 unsigned limit
= 500;
1385 spin_lock_irqsave(&master
->queue_lock
, flags
);
1388 * This is a bit lame, but is optimized for the common execution path.
1389 * A wait_queue on the master->busy could be used, but then the common
1390 * execution path (pump_messages) would be required to call wake_up or
1391 * friends on every SPI message. Do this instead.
1393 while ((!list_empty(&master
->queue
) || master
->busy
) && limit
--) {
1394 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1395 usleep_range(10000, 11000);
1396 spin_lock_irqsave(&master
->queue_lock
, flags
);
1399 if (!list_empty(&master
->queue
) || master
->busy
)
1402 master
->running
= false;
1404 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1407 dev_warn(&master
->dev
,
1408 "could not stop message queue\n");
1414 static int spi_destroy_queue(struct spi_master
*master
)
1418 ret
= spi_stop_queue(master
);
1421 * kthread_flush_worker will block until all work is done.
1422 * If the reason that stop_queue timed out is that the work will never
1423 * finish, then it does no good to call flush/stop thread, so
1427 dev_err(&master
->dev
, "problem destroying queue\n");
1431 kthread_flush_worker(&master
->kworker
);
1432 kthread_stop(master
->kworker_task
);
1437 static int __spi_queued_transfer(struct spi_device
*spi
,
1438 struct spi_message
*msg
,
1441 struct spi_master
*master
= spi
->master
;
1442 unsigned long flags
;
1444 spin_lock_irqsave(&master
->queue_lock
, flags
);
1446 if (!master
->running
) {
1447 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1450 msg
->actual_length
= 0;
1451 msg
->status
= -EINPROGRESS
;
1453 list_add_tail(&msg
->queue
, &master
->queue
);
1454 if (!master
->busy
&& need_pump
)
1455 kthread_queue_work(&master
->kworker
, &master
->pump_messages
);
1457 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1462 * spi_queued_transfer - transfer function for queued transfers
1463 * @spi: spi device which is requesting transfer
1464 * @msg: spi message which is to handled is queued to driver queue
1466 * Return: zero on success, else a negative error code.
1468 static int spi_queued_transfer(struct spi_device
*spi
, struct spi_message
*msg
)
1470 return __spi_queued_transfer(spi
, msg
, true);
1473 static int spi_master_initialize_queue(struct spi_master
*master
)
1477 master
->transfer
= spi_queued_transfer
;
1478 if (!master
->transfer_one_message
)
1479 master
->transfer_one_message
= spi_transfer_one_message
;
1481 /* Initialize and start queue */
1482 ret
= spi_init_queue(master
);
1484 dev_err(&master
->dev
, "problem initializing queue\n");
1485 goto err_init_queue
;
1487 master
->queued
= true;
1488 ret
= spi_start_queue(master
);
1490 dev_err(&master
->dev
, "problem starting queue\n");
1491 goto err_start_queue
;
1497 spi_destroy_queue(master
);
1502 /*-------------------------------------------------------------------------*/
1504 #if defined(CONFIG_OF)
1505 static struct spi_device
*
1506 of_register_spi_device(struct spi_master
*master
, struct device_node
*nc
)
1508 struct spi_device
*spi
;
1512 /* Alloc an spi_device */
1513 spi
= spi_alloc_device(master
);
1515 dev_err(&master
->dev
, "spi_device alloc error for %s\n",
1521 /* Select device driver */
1522 rc
= of_modalias_node(nc
, spi
->modalias
,
1523 sizeof(spi
->modalias
));
1525 dev_err(&master
->dev
, "cannot find modalias for %s\n",
1530 /* Device address */
1531 rc
= of_property_read_u32(nc
, "reg", &value
);
1533 dev_err(&master
->dev
, "%s has no valid 'reg' property (%d)\n",
1537 spi
->chip_select
= value
;
1539 /* Mode (clock phase/polarity/etc.) */
1540 if (of_find_property(nc
, "spi-cpha", NULL
))
1541 spi
->mode
|= SPI_CPHA
;
1542 if (of_find_property(nc
, "spi-cpol", NULL
))
1543 spi
->mode
|= SPI_CPOL
;
1544 if (of_find_property(nc
, "spi-cs-high", NULL
))
1545 spi
->mode
|= SPI_CS_HIGH
;
1546 if (of_find_property(nc
, "spi-3wire", NULL
))
1547 spi
->mode
|= SPI_3WIRE
;
1548 if (of_find_property(nc
, "spi-lsb-first", NULL
))
1549 spi
->mode
|= SPI_LSB_FIRST
;
1551 /* Device DUAL/QUAD mode */
1552 if (!of_property_read_u32(nc
, "spi-tx-bus-width", &value
)) {
1557 spi
->mode
|= SPI_TX_DUAL
;
1560 spi
->mode
|= SPI_TX_QUAD
;
1563 dev_warn(&master
->dev
,
1564 "spi-tx-bus-width %d not supported\n",
1570 if (!of_property_read_u32(nc
, "spi-rx-bus-width", &value
)) {
1575 spi
->mode
|= SPI_RX_DUAL
;
1578 spi
->mode
|= SPI_RX_QUAD
;
1581 dev_warn(&master
->dev
,
1582 "spi-rx-bus-width %d not supported\n",
1589 rc
= of_property_read_u32(nc
, "spi-max-frequency", &value
);
1591 dev_err(&master
->dev
, "%s has no valid 'spi-max-frequency' property (%d)\n",
1595 spi
->max_speed_hz
= value
;
1597 /* Store a pointer to the node in the device structure */
1599 spi
->dev
.of_node
= nc
;
1601 /* Register the new device */
1602 rc
= spi_add_device(spi
);
1604 dev_err(&master
->dev
, "spi_device register error %s\n",
1617 * of_register_spi_devices() - Register child devices onto the SPI bus
1618 * @master: Pointer to spi_master device
1620 * Registers an spi_device for each child node of master node which has a 'reg'
1623 static void of_register_spi_devices(struct spi_master
*master
)
1625 struct spi_device
*spi
;
1626 struct device_node
*nc
;
1628 if (!master
->dev
.of_node
)
1631 for_each_available_child_of_node(master
->dev
.of_node
, nc
) {
1632 if (of_node_test_and_set_flag(nc
, OF_POPULATED
))
1634 spi
= of_register_spi_device(master
, nc
);
1636 dev_warn(&master
->dev
, "Failed to create SPI device for %s\n",
1638 of_node_clear_flag(nc
, OF_POPULATED
);
1643 static void of_register_spi_devices(struct spi_master
*master
) { }
1647 static int acpi_spi_add_resource(struct acpi_resource
*ares
, void *data
)
1649 struct spi_device
*spi
= data
;
1650 struct spi_master
*master
= spi
->master
;
1652 if (ares
->type
== ACPI_RESOURCE_TYPE_SERIAL_BUS
) {
1653 struct acpi_resource_spi_serialbus
*sb
;
1655 sb
= &ares
->data
.spi_serial_bus
;
1656 if (sb
->type
== ACPI_RESOURCE_SERIAL_TYPE_SPI
) {
1658 * ACPI DeviceSelection numbering is handled by the
1659 * host controller driver in Windows and can vary
1660 * from driver to driver. In Linux we always expect
1661 * 0 .. max - 1 so we need to ask the driver to
1662 * translate between the two schemes.
1664 if (master
->fw_translate_cs
) {
1665 int cs
= master
->fw_translate_cs(master
,
1666 sb
->device_selection
);
1669 spi
->chip_select
= cs
;
1671 spi
->chip_select
= sb
->device_selection
;
1674 spi
->max_speed_hz
= sb
->connection_speed
;
1676 if (sb
->clock_phase
== ACPI_SPI_SECOND_PHASE
)
1677 spi
->mode
|= SPI_CPHA
;
1678 if (sb
->clock_polarity
== ACPI_SPI_START_HIGH
)
1679 spi
->mode
|= SPI_CPOL
;
1680 if (sb
->device_polarity
== ACPI_SPI_ACTIVE_HIGH
)
1681 spi
->mode
|= SPI_CS_HIGH
;
1683 } else if (spi
->irq
< 0) {
1686 if (acpi_dev_resource_interrupt(ares
, 0, &r
))
1690 /* Always tell the ACPI core to skip this resource */
1694 static acpi_status
acpi_register_spi_device(struct spi_master
*master
,
1695 struct acpi_device
*adev
)
1697 struct list_head resource_list
;
1698 struct spi_device
*spi
;
1701 if (acpi_bus_get_status(adev
) || !adev
->status
.present
||
1702 acpi_device_enumerated(adev
))
1705 spi
= spi_alloc_device(master
);
1707 dev_err(&master
->dev
, "failed to allocate SPI device for %s\n",
1708 dev_name(&adev
->dev
));
1709 return AE_NO_MEMORY
;
1712 ACPI_COMPANION_SET(&spi
->dev
, adev
);
1715 INIT_LIST_HEAD(&resource_list
);
1716 ret
= acpi_dev_get_resources(adev
, &resource_list
,
1717 acpi_spi_add_resource
, spi
);
1718 acpi_dev_free_resource_list(&resource_list
);
1720 if (ret
< 0 || !spi
->max_speed_hz
) {
1726 spi
->irq
= acpi_dev_gpio_irq_get(adev
, 0);
1728 acpi_device_set_enumerated(adev
);
1730 adev
->power
.flags
.ignore_parent
= true;
1731 strlcpy(spi
->modalias
, acpi_device_hid(adev
), sizeof(spi
->modalias
));
1732 if (spi_add_device(spi
)) {
1733 adev
->power
.flags
.ignore_parent
= false;
1734 dev_err(&master
->dev
, "failed to add SPI device %s from ACPI\n",
1735 dev_name(&adev
->dev
));
1742 static acpi_status
acpi_spi_add_device(acpi_handle handle
, u32 level
,
1743 void *data
, void **return_value
)
1745 struct spi_master
*master
= data
;
1746 struct acpi_device
*adev
;
1748 if (acpi_bus_get_device(handle
, &adev
))
1751 return acpi_register_spi_device(master
, adev
);
1754 static void acpi_register_spi_devices(struct spi_master
*master
)
1759 handle
= ACPI_HANDLE(master
->dev
.parent
);
1763 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, handle
, 1,
1764 acpi_spi_add_device
, NULL
,
1766 if (ACPI_FAILURE(status
))
1767 dev_warn(&master
->dev
, "failed to enumerate SPI slaves\n");
1770 static inline void acpi_register_spi_devices(struct spi_master
*master
) {}
1771 #endif /* CONFIG_ACPI */
1773 static void spi_master_release(struct device
*dev
)
1775 struct spi_master
*master
;
1777 master
= container_of(dev
, struct spi_master
, dev
);
1781 static struct class spi_master_class
= {
1782 .name
= "spi_master",
1783 .owner
= THIS_MODULE
,
1784 .dev_release
= spi_master_release
,
1785 .dev_groups
= spi_master_groups
,
1790 * spi_alloc_master - allocate SPI master controller
1791 * @dev: the controller, possibly using the platform_bus
1792 * @size: how much zeroed driver-private data to allocate; the pointer to this
1793 * memory is in the driver_data field of the returned device,
1794 * accessible with spi_master_get_devdata().
1795 * Context: can sleep
1797 * This call is used only by SPI master controller drivers, which are the
1798 * only ones directly touching chip registers. It's how they allocate
1799 * an spi_master structure, prior to calling spi_register_master().
1801 * This must be called from context that can sleep.
1803 * The caller is responsible for assigning the bus number and initializing
1804 * the master's methods before calling spi_register_master(); and (after errors
1805 * adding the device) calling spi_master_put() to prevent a memory leak.
1807 * Return: the SPI master structure on success, else NULL.
1809 struct spi_master
*spi_alloc_master(struct device
*dev
, unsigned size
)
1811 struct spi_master
*master
;
1816 master
= kzalloc(size
+ sizeof(*master
), GFP_KERNEL
);
1820 device_initialize(&master
->dev
);
1821 master
->bus_num
= -1;
1822 master
->num_chipselect
= 1;
1823 master
->dev
.class = &spi_master_class
;
1824 master
->dev
.parent
= dev
;
1825 pm_suspend_ignore_children(&master
->dev
, true);
1826 spi_master_set_devdata(master
, &master
[1]);
1830 EXPORT_SYMBOL_GPL(spi_alloc_master
);
1833 static int of_spi_register_master(struct spi_master
*master
)
1836 struct device_node
*np
= master
->dev
.of_node
;
1841 nb
= of_gpio_named_count(np
, "cs-gpios");
1842 master
->num_chipselect
= max_t(int, nb
, master
->num_chipselect
);
1844 /* Return error only for an incorrectly formed cs-gpios property */
1845 if (nb
== 0 || nb
== -ENOENT
)
1850 cs
= devm_kzalloc(&master
->dev
,
1851 sizeof(int) * master
->num_chipselect
,
1853 master
->cs_gpios
= cs
;
1855 if (!master
->cs_gpios
)
1858 for (i
= 0; i
< master
->num_chipselect
; i
++)
1861 for (i
= 0; i
< nb
; i
++)
1862 cs
[i
] = of_get_named_gpio(np
, "cs-gpios", i
);
1867 static int of_spi_register_master(struct spi_master
*master
)
1874 * spi_register_master - register SPI master controller
1875 * @master: initialized master, originally from spi_alloc_master()
1876 * Context: can sleep
1878 * SPI master controllers connect to their drivers using some non-SPI bus,
1879 * such as the platform bus. The final stage of probe() in that code
1880 * includes calling spi_register_master() to hook up to this SPI bus glue.
1882 * SPI controllers use board specific (often SOC specific) bus numbers,
1883 * and board-specific addressing for SPI devices combines those numbers
1884 * with chip select numbers. Since SPI does not directly support dynamic
1885 * device identification, boards need configuration tables telling which
1886 * chip is at which address.
1888 * This must be called from context that can sleep. It returns zero on
1889 * success, else a negative error code (dropping the master's refcount).
1890 * After a successful return, the caller is responsible for calling
1891 * spi_unregister_master().
1893 * Return: zero on success, else a negative error code.
1895 int spi_register_master(struct spi_master
*master
)
1897 static atomic_t dyn_bus_id
= ATOMIC_INIT((1<<15) - 1);
1898 struct device
*dev
= master
->dev
.parent
;
1899 struct boardinfo
*bi
;
1900 int status
= -ENODEV
;
1906 status
= of_spi_register_master(master
);
1910 /* even if it's just one always-selected device, there must
1911 * be at least one chipselect
1913 if (master
->num_chipselect
== 0)
1916 if ((master
->bus_num
< 0) && master
->dev
.of_node
)
1917 master
->bus_num
= of_alias_get_id(master
->dev
.of_node
, "spi");
1919 /* convention: dynamically assigned bus IDs count down from the max */
1920 if (master
->bus_num
< 0) {
1921 /* FIXME switch to an IDR based scheme, something like
1922 * I2C now uses, so we can't run out of "dynamic" IDs
1924 master
->bus_num
= atomic_dec_return(&dyn_bus_id
);
1928 INIT_LIST_HEAD(&master
->queue
);
1929 spin_lock_init(&master
->queue_lock
);
1930 spin_lock_init(&master
->bus_lock_spinlock
);
1931 mutex_init(&master
->bus_lock_mutex
);
1932 mutex_init(&master
->io_mutex
);
1933 master
->bus_lock_flag
= 0;
1934 init_completion(&master
->xfer_completion
);
1935 if (!master
->max_dma_len
)
1936 master
->max_dma_len
= INT_MAX
;
1938 /* register the device, then userspace will see it.
1939 * registration fails if the bus ID is in use.
1941 dev_set_name(&master
->dev
, "spi%u", master
->bus_num
);
1942 status
= device_add(&master
->dev
);
1945 dev_dbg(dev
, "registered master %s%s\n", dev_name(&master
->dev
),
1946 dynamic
? " (dynamic)" : "");
1948 /* If we're using a queued driver, start the queue */
1949 if (master
->transfer
)
1950 dev_info(dev
, "master is unqueued, this is deprecated\n");
1952 status
= spi_master_initialize_queue(master
);
1954 device_del(&master
->dev
);
1958 /* add statistics */
1959 spin_lock_init(&master
->statistics
.lock
);
1961 mutex_lock(&board_lock
);
1962 list_add_tail(&master
->list
, &spi_master_list
);
1963 list_for_each_entry(bi
, &board_list
, list
)
1964 spi_match_master_to_boardinfo(master
, &bi
->board_info
);
1965 mutex_unlock(&board_lock
);
1967 /* Register devices from the device tree and ACPI */
1968 of_register_spi_devices(master
);
1969 acpi_register_spi_devices(master
);
1973 EXPORT_SYMBOL_GPL(spi_register_master
);
1975 static void devm_spi_unregister(struct device
*dev
, void *res
)
1977 spi_unregister_master(*(struct spi_master
**)res
);
1981 * dev_spi_register_master - register managed SPI master controller
1982 * @dev: device managing SPI master
1983 * @master: initialized master, originally from spi_alloc_master()
1984 * Context: can sleep
1986 * Register a SPI device as with spi_register_master() which will
1987 * automatically be unregister
1989 * Return: zero on success, else a negative error code.
1991 int devm_spi_register_master(struct device
*dev
, struct spi_master
*master
)
1993 struct spi_master
**ptr
;
1996 ptr
= devres_alloc(devm_spi_unregister
, sizeof(*ptr
), GFP_KERNEL
);
2000 ret
= spi_register_master(master
);
2003 devres_add(dev
, ptr
);
2010 EXPORT_SYMBOL_GPL(devm_spi_register_master
);
2012 static int __unregister(struct device
*dev
, void *null
)
2014 spi_unregister_device(to_spi_device(dev
));
2019 * spi_unregister_master - unregister SPI master controller
2020 * @master: the master being unregistered
2021 * Context: can sleep
2023 * This call is used only by SPI master controller drivers, which are the
2024 * only ones directly touching chip registers.
2026 * This must be called from context that can sleep.
2028 void spi_unregister_master(struct spi_master
*master
)
2032 if (master
->queued
) {
2033 if (spi_destroy_queue(master
))
2034 dev_err(&master
->dev
, "queue remove failed\n");
2037 mutex_lock(&board_lock
);
2038 list_del(&master
->list
);
2039 mutex_unlock(&board_lock
);
2041 dummy
= device_for_each_child(&master
->dev
, NULL
, __unregister
);
2042 device_unregister(&master
->dev
);
2044 EXPORT_SYMBOL_GPL(spi_unregister_master
);
2046 int spi_master_suspend(struct spi_master
*master
)
2050 /* Basically no-ops for non-queued masters */
2051 if (!master
->queued
)
2054 ret
= spi_stop_queue(master
);
2056 dev_err(&master
->dev
, "queue stop failed\n");
2060 EXPORT_SYMBOL_GPL(spi_master_suspend
);
2062 int spi_master_resume(struct spi_master
*master
)
2066 if (!master
->queued
)
2069 ret
= spi_start_queue(master
);
2071 dev_err(&master
->dev
, "queue restart failed\n");
2075 EXPORT_SYMBOL_GPL(spi_master_resume
);
2077 static int __spi_master_match(struct device
*dev
, const void *data
)
2079 struct spi_master
*m
;
2080 const u16
*bus_num
= data
;
2082 m
= container_of(dev
, struct spi_master
, dev
);
2083 return m
->bus_num
== *bus_num
;
2087 * spi_busnum_to_master - look up master associated with bus_num
2088 * @bus_num: the master's bus number
2089 * Context: can sleep
2091 * This call may be used with devices that are registered after
2092 * arch init time. It returns a refcounted pointer to the relevant
2093 * spi_master (which the caller must release), or NULL if there is
2094 * no such master registered.
2096 * Return: the SPI master structure on success, else NULL.
2098 struct spi_master
*spi_busnum_to_master(u16 bus_num
)
2101 struct spi_master
*master
= NULL
;
2103 dev
= class_find_device(&spi_master_class
, NULL
, &bus_num
,
2104 __spi_master_match
);
2106 master
= container_of(dev
, struct spi_master
, dev
);
2107 /* reference got in class_find_device */
2110 EXPORT_SYMBOL_GPL(spi_busnum_to_master
);
2112 /*-------------------------------------------------------------------------*/
2114 /* Core methods for SPI resource management */
2117 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2118 * during the processing of a spi_message while using
2120 * @spi: the spi device for which we allocate memory
2121 * @release: the release code to execute for this resource
2122 * @size: size to alloc and return
2123 * @gfp: GFP allocation flags
2125 * Return: the pointer to the allocated data
2127 * This may get enhanced in the future to allocate from a memory pool
2128 * of the @spi_device or @spi_master to avoid repeated allocations.
2130 void *spi_res_alloc(struct spi_device
*spi
,
2131 spi_res_release_t release
,
2132 size_t size
, gfp_t gfp
)
2134 struct spi_res
*sres
;
2136 sres
= kzalloc(sizeof(*sres
) + size
, gfp
);
2140 INIT_LIST_HEAD(&sres
->entry
);
2141 sres
->release
= release
;
2145 EXPORT_SYMBOL_GPL(spi_res_alloc
);
2148 * spi_res_free - free an spi resource
2149 * @res: pointer to the custom data of a resource
2152 void spi_res_free(void *res
)
2154 struct spi_res
*sres
= container_of(res
, struct spi_res
, data
);
2159 WARN_ON(!list_empty(&sres
->entry
));
2162 EXPORT_SYMBOL_GPL(spi_res_free
);
2165 * spi_res_add - add a spi_res to the spi_message
2166 * @message: the spi message
2167 * @res: the spi_resource
2169 void spi_res_add(struct spi_message
*message
, void *res
)
2171 struct spi_res
*sres
= container_of(res
, struct spi_res
, data
);
2173 WARN_ON(!list_empty(&sres
->entry
));
2174 list_add_tail(&sres
->entry
, &message
->resources
);
2176 EXPORT_SYMBOL_GPL(spi_res_add
);
2179 * spi_res_release - release all spi resources for this message
2180 * @master: the @spi_master
2181 * @message: the @spi_message
2183 void spi_res_release(struct spi_master
*master
,
2184 struct spi_message
*message
)
2186 struct spi_res
*res
;
2188 while (!list_empty(&message
->resources
)) {
2189 res
= list_last_entry(&message
->resources
,
2190 struct spi_res
, entry
);
2193 res
->release(master
, message
, res
->data
);
2195 list_del(&res
->entry
);
2200 EXPORT_SYMBOL_GPL(spi_res_release
);
2202 /*-------------------------------------------------------------------------*/
2204 /* Core methods for spi_message alterations */
2206 static void __spi_replace_transfers_release(struct spi_master
*master
,
2207 struct spi_message
*msg
,
2210 struct spi_replaced_transfers
*rxfer
= res
;
2213 /* call extra callback if requested */
2215 rxfer
->release(master
, msg
, res
);
2217 /* insert replaced transfers back into the message */
2218 list_splice(&rxfer
->replaced_transfers
, rxfer
->replaced_after
);
2220 /* remove the formerly inserted entries */
2221 for (i
= 0; i
< rxfer
->inserted
; i
++)
2222 list_del(&rxfer
->inserted_transfers
[i
].transfer_list
);
2226 * spi_replace_transfers - replace transfers with several transfers
2227 * and register change with spi_message.resources
2228 * @msg: the spi_message we work upon
2229 * @xfer_first: the first spi_transfer we want to replace
2230 * @remove: number of transfers to remove
2231 * @insert: the number of transfers we want to insert instead
2232 * @release: extra release code necessary in some circumstances
2233 * @extradatasize: extra data to allocate (with alignment guarantees
2234 * of struct @spi_transfer)
2237 * Returns: pointer to @spi_replaced_transfers,
2238 * PTR_ERR(...) in case of errors.
2240 struct spi_replaced_transfers
*spi_replace_transfers(
2241 struct spi_message
*msg
,
2242 struct spi_transfer
*xfer_first
,
2245 spi_replaced_release_t release
,
2246 size_t extradatasize
,
2249 struct spi_replaced_transfers
*rxfer
;
2250 struct spi_transfer
*xfer
;
2253 /* allocate the structure using spi_res */
2254 rxfer
= spi_res_alloc(msg
->spi
, __spi_replace_transfers_release
,
2255 insert
* sizeof(struct spi_transfer
)
2256 + sizeof(struct spi_replaced_transfers
)
2260 return ERR_PTR(-ENOMEM
);
2262 /* the release code to invoke before running the generic release */
2263 rxfer
->release
= release
;
2265 /* assign extradata */
2268 &rxfer
->inserted_transfers
[insert
];
2270 /* init the replaced_transfers list */
2271 INIT_LIST_HEAD(&rxfer
->replaced_transfers
);
2273 /* assign the list_entry after which we should reinsert
2274 * the @replaced_transfers - it may be spi_message.messages!
2276 rxfer
->replaced_after
= xfer_first
->transfer_list
.prev
;
2278 /* remove the requested number of transfers */
2279 for (i
= 0; i
< remove
; i
++) {
2280 /* if the entry after replaced_after it is msg->transfers
2281 * then we have been requested to remove more transfers
2282 * than are in the list
2284 if (rxfer
->replaced_after
->next
== &msg
->transfers
) {
2285 dev_err(&msg
->spi
->dev
,
2286 "requested to remove more spi_transfers than are available\n");
2287 /* insert replaced transfers back into the message */
2288 list_splice(&rxfer
->replaced_transfers
,
2289 rxfer
->replaced_after
);
2291 /* free the spi_replace_transfer structure */
2292 spi_res_free(rxfer
);
2294 /* and return with an error */
2295 return ERR_PTR(-EINVAL
);
2298 /* remove the entry after replaced_after from list of
2299 * transfers and add it to list of replaced_transfers
2301 list_move_tail(rxfer
->replaced_after
->next
,
2302 &rxfer
->replaced_transfers
);
2305 /* create copy of the given xfer with identical settings
2306 * based on the first transfer to get removed
2308 for (i
= 0; i
< insert
; i
++) {
2309 /* we need to run in reverse order */
2310 xfer
= &rxfer
->inserted_transfers
[insert
- 1 - i
];
2312 /* copy all spi_transfer data */
2313 memcpy(xfer
, xfer_first
, sizeof(*xfer
));
2316 list_add(&xfer
->transfer_list
, rxfer
->replaced_after
);
2318 /* clear cs_change and delay_usecs for all but the last */
2320 xfer
->cs_change
= false;
2321 xfer
->delay_usecs
= 0;
2325 /* set up inserted */
2326 rxfer
->inserted
= insert
;
2328 /* and register it with spi_res/spi_message */
2329 spi_res_add(msg
, rxfer
);
2333 EXPORT_SYMBOL_GPL(spi_replace_transfers
);
2335 static int __spi_split_transfer_maxsize(struct spi_master
*master
,
2336 struct spi_message
*msg
,
2337 struct spi_transfer
**xferp
,
2341 struct spi_transfer
*xfer
= *xferp
, *xfers
;
2342 struct spi_replaced_transfers
*srt
;
2346 /* warn once about this fact that we are splitting a transfer */
2347 dev_warn_once(&msg
->spi
->dev
,
2348 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2349 xfer
->len
, maxsize
);
2351 /* calculate how many we have to replace */
2352 count
= DIV_ROUND_UP(xfer
->len
, maxsize
);
2354 /* create replacement */
2355 srt
= spi_replace_transfers(msg
, xfer
, 1, count
, NULL
, 0, gfp
);
2357 return PTR_ERR(srt
);
2358 xfers
= srt
->inserted_transfers
;
2360 /* now handle each of those newly inserted spi_transfers
2361 * note that the replacements spi_transfers all are preset
2362 * to the same values as *xferp, so tx_buf, rx_buf and len
2363 * are all identical (as well as most others)
2364 * so we just have to fix up len and the pointers.
2366 * this also includes support for the depreciated
2367 * spi_message.is_dma_mapped interface
2370 /* the first transfer just needs the length modified, so we
2371 * run it outside the loop
2373 xfers
[0].len
= min_t(size_t, maxsize
, xfer
[0].len
);
2375 /* all the others need rx_buf/tx_buf also set */
2376 for (i
= 1, offset
= maxsize
; i
< count
; offset
+= maxsize
, i
++) {
2377 /* update rx_buf, tx_buf and dma */
2378 if (xfers
[i
].rx_buf
)
2379 xfers
[i
].rx_buf
+= offset
;
2380 if (xfers
[i
].rx_dma
)
2381 xfers
[i
].rx_dma
+= offset
;
2382 if (xfers
[i
].tx_buf
)
2383 xfers
[i
].tx_buf
+= offset
;
2384 if (xfers
[i
].tx_dma
)
2385 xfers
[i
].tx_dma
+= offset
;
2388 xfers
[i
].len
= min(maxsize
, xfers
[i
].len
- offset
);
2391 /* we set up xferp to the last entry we have inserted,
2392 * so that we skip those already split transfers
2394 *xferp
= &xfers
[count
- 1];
2396 /* increment statistics counters */
2397 SPI_STATISTICS_INCREMENT_FIELD(&master
->statistics
,
2398 transfers_split_maxsize
);
2399 SPI_STATISTICS_INCREMENT_FIELD(&msg
->spi
->statistics
,
2400 transfers_split_maxsize
);
2406 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2407 * when an individual transfer exceeds a
2409 * @master: the @spi_master for this transfer
2410 * @msg: the @spi_message to transform
2411 * @maxsize: the maximum when to apply this
2412 * @gfp: GFP allocation flags
2414 * Return: status of transformation
2416 int spi_split_transfers_maxsize(struct spi_master
*master
,
2417 struct spi_message
*msg
,
2421 struct spi_transfer
*xfer
;
2424 /* iterate over the transfer_list,
2425 * but note that xfer is advanced to the last transfer inserted
2426 * to avoid checking sizes again unnecessarily (also xfer does
2427 * potentiall belong to a different list by the time the
2428 * replacement has happened
2430 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
2431 if (xfer
->len
> maxsize
) {
2432 ret
= __spi_split_transfer_maxsize(
2433 master
, msg
, &xfer
, maxsize
, gfp
);
2441 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize
);
2443 /*-------------------------------------------------------------------------*/
2445 /* Core methods for SPI master protocol drivers. Some of the
2446 * other core methods are currently defined as inline functions.
2449 static int __spi_validate_bits_per_word(struct spi_master
*master
, u8 bits_per_word
)
2451 if (master
->bits_per_word_mask
) {
2452 /* Only 32 bits fit in the mask */
2453 if (bits_per_word
> 32)
2455 if (!(master
->bits_per_word_mask
&
2456 SPI_BPW_MASK(bits_per_word
)))
2464 * spi_setup - setup SPI mode and clock rate
2465 * @spi: the device whose settings are being modified
2466 * Context: can sleep, and no requests are queued to the device
2468 * SPI protocol drivers may need to update the transfer mode if the
2469 * device doesn't work with its default. They may likewise need
2470 * to update clock rates or word sizes from initial values. This function
2471 * changes those settings, and must be called from a context that can sleep.
2472 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2473 * effect the next time the device is selected and data is transferred to
2474 * or from it. When this function returns, the spi device is deselected.
2476 * Note that this call will fail if the protocol driver specifies an option
2477 * that the underlying controller or its driver does not support. For
2478 * example, not all hardware supports wire transfers using nine bit words,
2479 * LSB-first wire encoding, or active-high chipselects.
2481 * Return: zero on success, else a negative error code.
2483 int spi_setup(struct spi_device
*spi
)
2485 unsigned bad_bits
, ugly_bits
;
2488 /* check mode to prevent that DUAL and QUAD set at the same time
2490 if (((spi
->mode
& SPI_TX_DUAL
) && (spi
->mode
& SPI_TX_QUAD
)) ||
2491 ((spi
->mode
& SPI_RX_DUAL
) && (spi
->mode
& SPI_RX_QUAD
))) {
2493 "setup: can not select dual and quad at the same time\n");
2496 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2498 if ((spi
->mode
& SPI_3WIRE
) && (spi
->mode
&
2499 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_RX_DUAL
| SPI_RX_QUAD
)))
2501 /* help drivers fail *cleanly* when they need options
2502 * that aren't supported with their current master
2504 bad_bits
= spi
->mode
& ~spi
->master
->mode_bits
;
2505 ugly_bits
= bad_bits
&
2506 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_RX_DUAL
| SPI_RX_QUAD
);
2509 "setup: ignoring unsupported mode bits %x\n",
2511 spi
->mode
&= ~ugly_bits
;
2512 bad_bits
&= ~ugly_bits
;
2515 dev_err(&spi
->dev
, "setup: unsupported mode bits %x\n",
2520 if (!spi
->bits_per_word
)
2521 spi
->bits_per_word
= 8;
2523 status
= __spi_validate_bits_per_word(spi
->master
, spi
->bits_per_word
);
2527 if (!spi
->max_speed_hz
)
2528 spi
->max_speed_hz
= spi
->master
->max_speed_hz
;
2530 if (spi
->master
->setup
)
2531 status
= spi
->master
->setup(spi
);
2533 spi_set_cs(spi
, false);
2535 dev_dbg(&spi
->dev
, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2536 (int) (spi
->mode
& (SPI_CPOL
| SPI_CPHA
)),
2537 (spi
->mode
& SPI_CS_HIGH
) ? "cs_high, " : "",
2538 (spi
->mode
& SPI_LSB_FIRST
) ? "lsb, " : "",
2539 (spi
->mode
& SPI_3WIRE
) ? "3wire, " : "",
2540 (spi
->mode
& SPI_LOOP
) ? "loopback, " : "",
2541 spi
->bits_per_word
, spi
->max_speed_hz
,
2546 EXPORT_SYMBOL_GPL(spi_setup
);
2548 static int __spi_validate(struct spi_device
*spi
, struct spi_message
*message
)
2550 struct spi_master
*master
= spi
->master
;
2551 struct spi_transfer
*xfer
;
2554 if (list_empty(&message
->transfers
))
2557 /* Half-duplex links include original MicroWire, and ones with
2558 * only one data pin like SPI_3WIRE (switches direction) or where
2559 * either MOSI or MISO is missing. They can also be caused by
2560 * software limitations.
2562 if ((master
->flags
& SPI_MASTER_HALF_DUPLEX
)
2563 || (spi
->mode
& SPI_3WIRE
)) {
2564 unsigned flags
= master
->flags
;
2566 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
2567 if (xfer
->rx_buf
&& xfer
->tx_buf
)
2569 if ((flags
& SPI_MASTER_NO_TX
) && xfer
->tx_buf
)
2571 if ((flags
& SPI_MASTER_NO_RX
) && xfer
->rx_buf
)
2577 * Set transfer bits_per_word and max speed as spi device default if
2578 * it is not set for this transfer.
2579 * Set transfer tx_nbits and rx_nbits as single transfer default
2580 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2582 message
->frame_length
= 0;
2583 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
2584 message
->frame_length
+= xfer
->len
;
2585 if (!xfer
->bits_per_word
)
2586 xfer
->bits_per_word
= spi
->bits_per_word
;
2588 if (!xfer
->speed_hz
)
2589 xfer
->speed_hz
= spi
->max_speed_hz
;
2590 if (!xfer
->speed_hz
)
2591 xfer
->speed_hz
= master
->max_speed_hz
;
2593 if (master
->max_speed_hz
&&
2594 xfer
->speed_hz
> master
->max_speed_hz
)
2595 xfer
->speed_hz
= master
->max_speed_hz
;
2597 if (__spi_validate_bits_per_word(master
, xfer
->bits_per_word
))
2601 * SPI transfer length should be multiple of SPI word size
2602 * where SPI word size should be power-of-two multiple
2604 if (xfer
->bits_per_word
<= 8)
2606 else if (xfer
->bits_per_word
<= 16)
2611 /* No partial transfers accepted */
2612 if (xfer
->len
% w_size
)
2615 if (xfer
->speed_hz
&& master
->min_speed_hz
&&
2616 xfer
->speed_hz
< master
->min_speed_hz
)
2619 if (xfer
->tx_buf
&& !xfer
->tx_nbits
)
2620 xfer
->tx_nbits
= SPI_NBITS_SINGLE
;
2621 if (xfer
->rx_buf
&& !xfer
->rx_nbits
)
2622 xfer
->rx_nbits
= SPI_NBITS_SINGLE
;
2623 /* check transfer tx/rx_nbits:
2624 * 1. check the value matches one of single, dual and quad
2625 * 2. check tx/rx_nbits match the mode in spi_device
2628 if (xfer
->tx_nbits
!= SPI_NBITS_SINGLE
&&
2629 xfer
->tx_nbits
!= SPI_NBITS_DUAL
&&
2630 xfer
->tx_nbits
!= SPI_NBITS_QUAD
)
2632 if ((xfer
->tx_nbits
== SPI_NBITS_DUAL
) &&
2633 !(spi
->mode
& (SPI_TX_DUAL
| SPI_TX_QUAD
)))
2635 if ((xfer
->tx_nbits
== SPI_NBITS_QUAD
) &&
2636 !(spi
->mode
& SPI_TX_QUAD
))
2639 /* check transfer rx_nbits */
2641 if (xfer
->rx_nbits
!= SPI_NBITS_SINGLE
&&
2642 xfer
->rx_nbits
!= SPI_NBITS_DUAL
&&
2643 xfer
->rx_nbits
!= SPI_NBITS_QUAD
)
2645 if ((xfer
->rx_nbits
== SPI_NBITS_DUAL
) &&
2646 !(spi
->mode
& (SPI_RX_DUAL
| SPI_RX_QUAD
)))
2648 if ((xfer
->rx_nbits
== SPI_NBITS_QUAD
) &&
2649 !(spi
->mode
& SPI_RX_QUAD
))
2654 message
->status
= -EINPROGRESS
;
2659 static int __spi_async(struct spi_device
*spi
, struct spi_message
*message
)
2661 struct spi_master
*master
= spi
->master
;
2665 SPI_STATISTICS_INCREMENT_FIELD(&master
->statistics
, spi_async
);
2666 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
, spi_async
);
2668 trace_spi_message_submit(message
);
2670 return master
->transfer(spi
, message
);
2674 * spi_async - asynchronous SPI transfer
2675 * @spi: device with which data will be exchanged
2676 * @message: describes the data transfers, including completion callback
2677 * Context: any (irqs may be blocked, etc)
2679 * This call may be used in_irq and other contexts which can't sleep,
2680 * as well as from task contexts which can sleep.
2682 * The completion callback is invoked in a context which can't sleep.
2683 * Before that invocation, the value of message->status is undefined.
2684 * When the callback is issued, message->status holds either zero (to
2685 * indicate complete success) or a negative error code. After that
2686 * callback returns, the driver which issued the transfer request may
2687 * deallocate the associated memory; it's no longer in use by any SPI
2688 * core or controller driver code.
2690 * Note that although all messages to a spi_device are handled in
2691 * FIFO order, messages may go to different devices in other orders.
2692 * Some device might be higher priority, or have various "hard" access
2693 * time requirements, for example.
2695 * On detection of any fault during the transfer, processing of
2696 * the entire message is aborted, and the device is deselected.
2697 * Until returning from the associated message completion callback,
2698 * no other spi_message queued to that device will be processed.
2699 * (This rule applies equally to all the synchronous transfer calls,
2700 * which are wrappers around this core asynchronous primitive.)
2702 * Return: zero on success, else a negative error code.
2704 int spi_async(struct spi_device
*spi
, struct spi_message
*message
)
2706 struct spi_master
*master
= spi
->master
;
2708 unsigned long flags
;
2710 ret
= __spi_validate(spi
, message
);
2714 spin_lock_irqsave(&master
->bus_lock_spinlock
, flags
);
2716 if (master
->bus_lock_flag
)
2719 ret
= __spi_async(spi
, message
);
2721 spin_unlock_irqrestore(&master
->bus_lock_spinlock
, flags
);
2725 EXPORT_SYMBOL_GPL(spi_async
);
2728 * spi_async_locked - version of spi_async with exclusive bus usage
2729 * @spi: device with which data will be exchanged
2730 * @message: describes the data transfers, including completion callback
2731 * Context: any (irqs may be blocked, etc)
2733 * This call may be used in_irq and other contexts which can't sleep,
2734 * as well as from task contexts which can sleep.
2736 * The completion callback is invoked in a context which can't sleep.
2737 * Before that invocation, the value of message->status is undefined.
2738 * When the callback is issued, message->status holds either zero (to
2739 * indicate complete success) or a negative error code. After that
2740 * callback returns, the driver which issued the transfer request may
2741 * deallocate the associated memory; it's no longer in use by any SPI
2742 * core or controller driver code.
2744 * Note that although all messages to a spi_device are handled in
2745 * FIFO order, messages may go to different devices in other orders.
2746 * Some device might be higher priority, or have various "hard" access
2747 * time requirements, for example.
2749 * On detection of any fault during the transfer, processing of
2750 * the entire message is aborted, and the device is deselected.
2751 * Until returning from the associated message completion callback,
2752 * no other spi_message queued to that device will be processed.
2753 * (This rule applies equally to all the synchronous transfer calls,
2754 * which are wrappers around this core asynchronous primitive.)
2756 * Return: zero on success, else a negative error code.
2758 int spi_async_locked(struct spi_device
*spi
, struct spi_message
*message
)
2760 struct spi_master
*master
= spi
->master
;
2762 unsigned long flags
;
2764 ret
= __spi_validate(spi
, message
);
2768 spin_lock_irqsave(&master
->bus_lock_spinlock
, flags
);
2770 ret
= __spi_async(spi
, message
);
2772 spin_unlock_irqrestore(&master
->bus_lock_spinlock
, flags
);
2777 EXPORT_SYMBOL_GPL(spi_async_locked
);
2780 int spi_flash_read(struct spi_device
*spi
,
2781 struct spi_flash_read_message
*msg
)
2784 struct spi_master
*master
= spi
->master
;
2785 struct device
*rx_dev
= NULL
;
2788 if ((msg
->opcode_nbits
== SPI_NBITS_DUAL
||
2789 msg
->addr_nbits
== SPI_NBITS_DUAL
) &&
2790 !(spi
->mode
& (SPI_TX_DUAL
| SPI_TX_QUAD
)))
2792 if ((msg
->opcode_nbits
== SPI_NBITS_QUAD
||
2793 msg
->addr_nbits
== SPI_NBITS_QUAD
) &&
2794 !(spi
->mode
& SPI_TX_QUAD
))
2796 if (msg
->data_nbits
== SPI_NBITS_DUAL
&&
2797 !(spi
->mode
& (SPI_RX_DUAL
| SPI_RX_QUAD
)))
2799 if (msg
->data_nbits
== SPI_NBITS_QUAD
&&
2800 !(spi
->mode
& SPI_RX_QUAD
))
2803 if (master
->auto_runtime_pm
) {
2804 ret
= pm_runtime_get_sync(master
->dev
.parent
);
2806 dev_err(&master
->dev
, "Failed to power device: %d\n",
2812 mutex_lock(&master
->bus_lock_mutex
);
2813 mutex_lock(&master
->io_mutex
);
2814 if (master
->dma_rx
) {
2815 rx_dev
= master
->dma_rx
->device
->dev
;
2816 ret
= spi_map_buf(master
, rx_dev
, &msg
->rx_sg
,
2820 msg
->cur_msg_mapped
= true;
2822 ret
= master
->spi_flash_read(spi
, msg
);
2823 if (msg
->cur_msg_mapped
)
2824 spi_unmap_buf(master
, rx_dev
, &msg
->rx_sg
,
2826 mutex_unlock(&master
->io_mutex
);
2827 mutex_unlock(&master
->bus_lock_mutex
);
2829 if (master
->auto_runtime_pm
)
2830 pm_runtime_put(master
->dev
.parent
);
2834 EXPORT_SYMBOL_GPL(spi_flash_read
);
2836 /*-------------------------------------------------------------------------*/
2838 /* Utility methods for SPI master protocol drivers, layered on
2839 * top of the core. Some other utility methods are defined as
2843 static void spi_complete(void *arg
)
2848 static int __spi_sync(struct spi_device
*spi
, struct spi_message
*message
)
2850 DECLARE_COMPLETION_ONSTACK(done
);
2852 struct spi_master
*master
= spi
->master
;
2853 unsigned long flags
;
2855 status
= __spi_validate(spi
, message
);
2859 message
->complete
= spi_complete
;
2860 message
->context
= &done
;
2863 SPI_STATISTICS_INCREMENT_FIELD(&master
->statistics
, spi_sync
);
2864 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
, spi_sync
);
2866 /* If we're not using the legacy transfer method then we will
2867 * try to transfer in the calling context so special case.
2868 * This code would be less tricky if we could remove the
2869 * support for driver implemented message queues.
2871 if (master
->transfer
== spi_queued_transfer
) {
2872 spin_lock_irqsave(&master
->bus_lock_spinlock
, flags
);
2874 trace_spi_message_submit(message
);
2876 status
= __spi_queued_transfer(spi
, message
, false);
2878 spin_unlock_irqrestore(&master
->bus_lock_spinlock
, flags
);
2880 status
= spi_async_locked(spi
, message
);
2884 /* Push out the messages in the calling context if we
2887 if (master
->transfer
== spi_queued_transfer
) {
2888 SPI_STATISTICS_INCREMENT_FIELD(&master
->statistics
,
2889 spi_sync_immediate
);
2890 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
,
2891 spi_sync_immediate
);
2892 __spi_pump_messages(master
, false);
2895 wait_for_completion(&done
);
2896 status
= message
->status
;
2898 message
->context
= NULL
;
2903 * spi_sync - blocking/synchronous SPI data transfers
2904 * @spi: device with which data will be exchanged
2905 * @message: describes the data transfers
2906 * Context: can sleep
2908 * This call may only be used from a context that may sleep. The sleep
2909 * is non-interruptible, and has no timeout. Low-overhead controller
2910 * drivers may DMA directly into and out of the message buffers.
2912 * Note that the SPI device's chip select is active during the message,
2913 * and then is normally disabled between messages. Drivers for some
2914 * frequently-used devices may want to minimize costs of selecting a chip,
2915 * by leaving it selected in anticipation that the next message will go
2916 * to the same chip. (That may increase power usage.)
2918 * Also, the caller is guaranteeing that the memory associated with the
2919 * message will not be freed before this call returns.
2921 * Return: zero on success, else a negative error code.
2923 int spi_sync(struct spi_device
*spi
, struct spi_message
*message
)
2927 mutex_lock(&spi
->master
->bus_lock_mutex
);
2928 ret
= __spi_sync(spi
, message
);
2929 mutex_unlock(&spi
->master
->bus_lock_mutex
);
2933 EXPORT_SYMBOL_GPL(spi_sync
);
2936 * spi_sync_locked - version of spi_sync with exclusive bus usage
2937 * @spi: device with which data will be exchanged
2938 * @message: describes the data transfers
2939 * Context: can sleep
2941 * This call may only be used from a context that may sleep. The sleep
2942 * is non-interruptible, and has no timeout. Low-overhead controller
2943 * drivers may DMA directly into and out of the message buffers.
2945 * This call should be used by drivers that require exclusive access to the
2946 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
2947 * be released by a spi_bus_unlock call when the exclusive access is over.
2949 * Return: zero on success, else a negative error code.
2951 int spi_sync_locked(struct spi_device
*spi
, struct spi_message
*message
)
2953 return __spi_sync(spi
, message
);
2955 EXPORT_SYMBOL_GPL(spi_sync_locked
);
2958 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2959 * @master: SPI bus master that should be locked for exclusive bus access
2960 * Context: can sleep
2962 * This call may only be used from a context that may sleep. The sleep
2963 * is non-interruptible, and has no timeout.
2965 * This call should be used by drivers that require exclusive access to the
2966 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2967 * exclusive access is over. Data transfer must be done by spi_sync_locked
2968 * and spi_async_locked calls when the SPI bus lock is held.
2970 * Return: always zero.
2972 int spi_bus_lock(struct spi_master
*master
)
2974 unsigned long flags
;
2976 mutex_lock(&master
->bus_lock_mutex
);
2978 spin_lock_irqsave(&master
->bus_lock_spinlock
, flags
);
2979 master
->bus_lock_flag
= 1;
2980 spin_unlock_irqrestore(&master
->bus_lock_spinlock
, flags
);
2982 /* mutex remains locked until spi_bus_unlock is called */
2986 EXPORT_SYMBOL_GPL(spi_bus_lock
);
2989 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2990 * @master: SPI bus master that was locked for exclusive bus access
2991 * Context: can sleep
2993 * This call may only be used from a context that may sleep. The sleep
2994 * is non-interruptible, and has no timeout.
2996 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2999 * Return: always zero.
3001 int spi_bus_unlock(struct spi_master
*master
)
3003 master
->bus_lock_flag
= 0;
3005 mutex_unlock(&master
->bus_lock_mutex
);
3009 EXPORT_SYMBOL_GPL(spi_bus_unlock
);
3011 /* portable code must never pass more than 32 bytes */
3012 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3017 * spi_write_then_read - SPI synchronous write followed by read
3018 * @spi: device with which data will be exchanged
3019 * @txbuf: data to be written (need not be dma-safe)
3020 * @n_tx: size of txbuf, in bytes
3021 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3022 * @n_rx: size of rxbuf, in bytes
3023 * Context: can sleep
3025 * This performs a half duplex MicroWire style transaction with the
3026 * device, sending txbuf and then reading rxbuf. The return value
3027 * is zero for success, else a negative errno status code.
3028 * This call may only be used from a context that may sleep.
3030 * Parameters to this routine are always copied using a small buffer;
3031 * portable code should never use this for more than 32 bytes.
3032 * Performance-sensitive or bulk transfer code should instead use
3033 * spi_{async,sync}() calls with dma-safe buffers.
3035 * Return: zero on success, else a negative error code.
3037 int spi_write_then_read(struct spi_device
*spi
,
3038 const void *txbuf
, unsigned n_tx
,
3039 void *rxbuf
, unsigned n_rx
)
3041 static DEFINE_MUTEX(lock
);
3044 struct spi_message message
;
3045 struct spi_transfer x
[2];
3048 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3049 * copying here, (as a pure convenience thing), but we can
3050 * keep heap costs out of the hot path unless someone else is
3051 * using the pre-allocated buffer or the transfer is too large.
3053 if ((n_tx
+ n_rx
) > SPI_BUFSIZ
|| !mutex_trylock(&lock
)) {
3054 local_buf
= kmalloc(max((unsigned)SPI_BUFSIZ
, n_tx
+ n_rx
),
3055 GFP_KERNEL
| GFP_DMA
);
3062 spi_message_init(&message
);
3063 memset(x
, 0, sizeof(x
));
3066 spi_message_add_tail(&x
[0], &message
);
3070 spi_message_add_tail(&x
[1], &message
);
3073 memcpy(local_buf
, txbuf
, n_tx
);
3074 x
[0].tx_buf
= local_buf
;
3075 x
[1].rx_buf
= local_buf
+ n_tx
;
3078 status
= spi_sync(spi
, &message
);
3080 memcpy(rxbuf
, x
[1].rx_buf
, n_rx
);
3082 if (x
[0].tx_buf
== buf
)
3083 mutex_unlock(&lock
);
3089 EXPORT_SYMBOL_GPL(spi_write_then_read
);
3091 /*-------------------------------------------------------------------------*/
3093 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
3094 static int __spi_of_device_match(struct device
*dev
, void *data
)
3096 return dev
->of_node
== data
;
3099 /* must call put_device() when done with returned spi_device device */
3100 static struct spi_device
*of_find_spi_device_by_node(struct device_node
*node
)
3102 struct device
*dev
= bus_find_device(&spi_bus_type
, NULL
, node
,
3103 __spi_of_device_match
);
3104 return dev
? to_spi_device(dev
) : NULL
;
3107 static int __spi_of_master_match(struct device
*dev
, const void *data
)
3109 return dev
->of_node
== data
;
3112 /* the spi masters are not using spi_bus, so we find it with another way */
3113 static struct spi_master
*of_find_spi_master_by_node(struct device_node
*node
)
3117 dev
= class_find_device(&spi_master_class
, NULL
, node
,
3118 __spi_of_master_match
);
3122 /* reference got in class_find_device */
3123 return container_of(dev
, struct spi_master
, dev
);
3126 static int of_spi_notify(struct notifier_block
*nb
, unsigned long action
,
3129 struct of_reconfig_data
*rd
= arg
;
3130 struct spi_master
*master
;
3131 struct spi_device
*spi
;
3133 switch (of_reconfig_get_state_change(action
, arg
)) {
3134 case OF_RECONFIG_CHANGE_ADD
:
3135 master
= of_find_spi_master_by_node(rd
->dn
->parent
);
3137 return NOTIFY_OK
; /* not for us */
3139 if (of_node_test_and_set_flag(rd
->dn
, OF_POPULATED
)) {
3140 put_device(&master
->dev
);
3144 spi
= of_register_spi_device(master
, rd
->dn
);
3145 put_device(&master
->dev
);
3148 pr_err("%s: failed to create for '%s'\n",
3149 __func__
, rd
->dn
->full_name
);
3150 of_node_clear_flag(rd
->dn
, OF_POPULATED
);
3151 return notifier_from_errno(PTR_ERR(spi
));
3155 case OF_RECONFIG_CHANGE_REMOVE
:
3156 /* already depopulated? */
3157 if (!of_node_check_flag(rd
->dn
, OF_POPULATED
))
3160 /* find our device by node */
3161 spi
= of_find_spi_device_by_node(rd
->dn
);
3163 return NOTIFY_OK
; /* no? not meant for us */
3165 /* unregister takes one ref away */
3166 spi_unregister_device(spi
);
3168 /* and put the reference of the find */
3169 put_device(&spi
->dev
);
3176 static struct notifier_block spi_of_notifier
= {
3177 .notifier_call
= of_spi_notify
,
3179 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3180 extern struct notifier_block spi_of_notifier
;
3181 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3183 #if IS_ENABLED(CONFIG_ACPI)
3184 static int spi_acpi_master_match(struct device
*dev
, const void *data
)
3186 return ACPI_COMPANION(dev
->parent
) == data
;
3189 static int spi_acpi_device_match(struct device
*dev
, void *data
)
3191 return ACPI_COMPANION(dev
) == data
;
3194 static struct spi_master
*acpi_spi_find_master_by_adev(struct acpi_device
*adev
)
3198 dev
= class_find_device(&spi_master_class
, NULL
, adev
,
3199 spi_acpi_master_match
);
3203 return container_of(dev
, struct spi_master
, dev
);
3206 static struct spi_device
*acpi_spi_find_device_by_adev(struct acpi_device
*adev
)
3210 dev
= bus_find_device(&spi_bus_type
, NULL
, adev
, spi_acpi_device_match
);
3212 return dev
? to_spi_device(dev
) : NULL
;
3215 static int acpi_spi_notify(struct notifier_block
*nb
, unsigned long value
,
3218 struct acpi_device
*adev
= arg
;
3219 struct spi_master
*master
;
3220 struct spi_device
*spi
;
3223 case ACPI_RECONFIG_DEVICE_ADD
:
3224 master
= acpi_spi_find_master_by_adev(adev
->parent
);
3228 acpi_register_spi_device(master
, adev
);
3229 put_device(&master
->dev
);
3231 case ACPI_RECONFIG_DEVICE_REMOVE
:
3232 if (!acpi_device_enumerated(adev
))
3235 spi
= acpi_spi_find_device_by_adev(adev
);
3239 spi_unregister_device(spi
);
3240 put_device(&spi
->dev
);
3247 static struct notifier_block spi_acpi_notifier
= {
3248 .notifier_call
= acpi_spi_notify
,
3251 extern struct notifier_block spi_acpi_notifier
;
3254 static int __init
spi_init(void)
3258 buf
= kmalloc(SPI_BUFSIZ
, GFP_KERNEL
);
3264 status
= bus_register(&spi_bus_type
);
3268 status
= class_register(&spi_master_class
);
3272 if (IS_ENABLED(CONFIG_OF_DYNAMIC
))
3273 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier
));
3274 if (IS_ENABLED(CONFIG_ACPI
))
3275 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier
));
3280 bus_unregister(&spi_bus_type
);
3288 /* board_info is normally registered in arch_initcall(),
3289 * but even essential drivers wait till later
3291 * REVISIT only boardinfo really needs static linking. the rest (device and
3292 * driver registration) _could_ be dynamically linked (modular) ... costs
3293 * include needing to have boardinfo data structures be much more public.
3295 postcore_initcall(spi_init
);