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>
41 #define CREATE_TRACE_POINTS
42 #include <trace/events/spi.h>
44 static void spidev_release(struct device
*dev
)
46 struct spi_device
*spi
= to_spi_device(dev
);
48 /* spi masters may cleanup for released devices */
49 if (spi
->master
->cleanup
)
50 spi
->master
->cleanup(spi
);
52 spi_master_put(spi
->master
);
57 modalias_show(struct device
*dev
, struct device_attribute
*a
, char *buf
)
59 const struct spi_device
*spi
= to_spi_device(dev
);
62 len
= acpi_device_modalias(dev
, buf
, PAGE_SIZE
- 1);
66 return sprintf(buf
, "%s%s\n", SPI_MODULE_PREFIX
, spi
->modalias
);
68 static DEVICE_ATTR_RO(modalias
);
70 #define SPI_STATISTICS_ATTRS(field, file) \
71 static ssize_t spi_master_##field##_show(struct device *dev, \
72 struct device_attribute *attr, \
75 struct spi_master *master = container_of(dev, \
76 struct spi_master, dev); \
77 return spi_statistics_##field##_show(&master->statistics, buf); \
79 static struct device_attribute dev_attr_spi_master_##field = { \
80 .attr = { .name = file, .mode = S_IRUGO }, \
81 .show = spi_master_##field##_show, \
83 static ssize_t spi_device_##field##_show(struct device *dev, \
84 struct device_attribute *attr, \
87 struct spi_device *spi = to_spi_device(dev); \
88 return spi_statistics_##field##_show(&spi->statistics, buf); \
90 static struct device_attribute dev_attr_spi_device_##field = { \
91 .attr = { .name = file, .mode = S_IRUGO }, \
92 .show = spi_device_##field##_show, \
95 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
96 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
99 unsigned long flags; \
101 spin_lock_irqsave(&stat->lock, flags); \
102 len = sprintf(buf, format_string, stat->field); \
103 spin_unlock_irqrestore(&stat->lock, flags); \
106 SPI_STATISTICS_ATTRS(name, file)
108 #define SPI_STATISTICS_SHOW(field, format_string) \
109 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
110 field, format_string)
112 SPI_STATISTICS_SHOW(messages
, "%lu");
113 SPI_STATISTICS_SHOW(transfers
, "%lu");
114 SPI_STATISTICS_SHOW(errors
, "%lu");
115 SPI_STATISTICS_SHOW(timedout
, "%lu");
117 SPI_STATISTICS_SHOW(spi_sync
, "%lu");
118 SPI_STATISTICS_SHOW(spi_sync_immediate
, "%lu");
119 SPI_STATISTICS_SHOW(spi_async
, "%lu");
121 SPI_STATISTICS_SHOW(bytes
, "%llu");
122 SPI_STATISTICS_SHOW(bytes_rx
, "%llu");
123 SPI_STATISTICS_SHOW(bytes_tx
, "%llu");
125 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
126 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
127 "transfer_bytes_histo_" number, \
128 transfer_bytes_histo[index], "%lu")
129 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
130 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
131 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
132 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
133 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
134 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
135 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
136 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
137 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
138 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
139 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
140 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
141 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
142 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
143 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
144 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
145 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
147 SPI_STATISTICS_SHOW(transfers_split_maxsize
, "%lu");
149 static struct attribute
*spi_dev_attrs
[] = {
150 &dev_attr_modalias
.attr
,
154 static const struct attribute_group spi_dev_group
= {
155 .attrs
= spi_dev_attrs
,
158 static struct attribute
*spi_device_statistics_attrs
[] = {
159 &dev_attr_spi_device_messages
.attr
,
160 &dev_attr_spi_device_transfers
.attr
,
161 &dev_attr_spi_device_errors
.attr
,
162 &dev_attr_spi_device_timedout
.attr
,
163 &dev_attr_spi_device_spi_sync
.attr
,
164 &dev_attr_spi_device_spi_sync_immediate
.attr
,
165 &dev_attr_spi_device_spi_async
.attr
,
166 &dev_attr_spi_device_bytes
.attr
,
167 &dev_attr_spi_device_bytes_rx
.attr
,
168 &dev_attr_spi_device_bytes_tx
.attr
,
169 &dev_attr_spi_device_transfer_bytes_histo0
.attr
,
170 &dev_attr_spi_device_transfer_bytes_histo1
.attr
,
171 &dev_attr_spi_device_transfer_bytes_histo2
.attr
,
172 &dev_attr_spi_device_transfer_bytes_histo3
.attr
,
173 &dev_attr_spi_device_transfer_bytes_histo4
.attr
,
174 &dev_attr_spi_device_transfer_bytes_histo5
.attr
,
175 &dev_attr_spi_device_transfer_bytes_histo6
.attr
,
176 &dev_attr_spi_device_transfer_bytes_histo7
.attr
,
177 &dev_attr_spi_device_transfer_bytes_histo8
.attr
,
178 &dev_attr_spi_device_transfer_bytes_histo9
.attr
,
179 &dev_attr_spi_device_transfer_bytes_histo10
.attr
,
180 &dev_attr_spi_device_transfer_bytes_histo11
.attr
,
181 &dev_attr_spi_device_transfer_bytes_histo12
.attr
,
182 &dev_attr_spi_device_transfer_bytes_histo13
.attr
,
183 &dev_attr_spi_device_transfer_bytes_histo14
.attr
,
184 &dev_attr_spi_device_transfer_bytes_histo15
.attr
,
185 &dev_attr_spi_device_transfer_bytes_histo16
.attr
,
186 &dev_attr_spi_device_transfers_split_maxsize
.attr
,
190 static const struct attribute_group spi_device_statistics_group
= {
191 .name
= "statistics",
192 .attrs
= spi_device_statistics_attrs
,
195 static const struct attribute_group
*spi_dev_groups
[] = {
197 &spi_device_statistics_group
,
201 static struct attribute
*spi_master_statistics_attrs
[] = {
202 &dev_attr_spi_master_messages
.attr
,
203 &dev_attr_spi_master_transfers
.attr
,
204 &dev_attr_spi_master_errors
.attr
,
205 &dev_attr_spi_master_timedout
.attr
,
206 &dev_attr_spi_master_spi_sync
.attr
,
207 &dev_attr_spi_master_spi_sync_immediate
.attr
,
208 &dev_attr_spi_master_spi_async
.attr
,
209 &dev_attr_spi_master_bytes
.attr
,
210 &dev_attr_spi_master_bytes_rx
.attr
,
211 &dev_attr_spi_master_bytes_tx
.attr
,
212 &dev_attr_spi_master_transfer_bytes_histo0
.attr
,
213 &dev_attr_spi_master_transfer_bytes_histo1
.attr
,
214 &dev_attr_spi_master_transfer_bytes_histo2
.attr
,
215 &dev_attr_spi_master_transfer_bytes_histo3
.attr
,
216 &dev_attr_spi_master_transfer_bytes_histo4
.attr
,
217 &dev_attr_spi_master_transfer_bytes_histo5
.attr
,
218 &dev_attr_spi_master_transfer_bytes_histo6
.attr
,
219 &dev_attr_spi_master_transfer_bytes_histo7
.attr
,
220 &dev_attr_spi_master_transfer_bytes_histo8
.attr
,
221 &dev_attr_spi_master_transfer_bytes_histo9
.attr
,
222 &dev_attr_spi_master_transfer_bytes_histo10
.attr
,
223 &dev_attr_spi_master_transfer_bytes_histo11
.attr
,
224 &dev_attr_spi_master_transfer_bytes_histo12
.attr
,
225 &dev_attr_spi_master_transfer_bytes_histo13
.attr
,
226 &dev_attr_spi_master_transfer_bytes_histo14
.attr
,
227 &dev_attr_spi_master_transfer_bytes_histo15
.attr
,
228 &dev_attr_spi_master_transfer_bytes_histo16
.attr
,
229 &dev_attr_spi_master_transfers_split_maxsize
.attr
,
233 static const struct attribute_group spi_master_statistics_group
= {
234 .name
= "statistics",
235 .attrs
= spi_master_statistics_attrs
,
238 static const struct attribute_group
*spi_master_groups
[] = {
239 &spi_master_statistics_group
,
243 void spi_statistics_add_transfer_stats(struct spi_statistics
*stats
,
244 struct spi_transfer
*xfer
,
245 struct spi_master
*master
)
248 int l2len
= min(fls(xfer
->len
), SPI_STATISTICS_HISTO_SIZE
) - 1;
253 spin_lock_irqsave(&stats
->lock
, flags
);
256 stats
->transfer_bytes_histo
[l2len
]++;
258 stats
->bytes
+= xfer
->len
;
259 if ((xfer
->tx_buf
) &&
260 (xfer
->tx_buf
!= master
->dummy_tx
))
261 stats
->bytes_tx
+= xfer
->len
;
262 if ((xfer
->rx_buf
) &&
263 (xfer
->rx_buf
!= master
->dummy_rx
))
264 stats
->bytes_rx
+= xfer
->len
;
266 spin_unlock_irqrestore(&stats
->lock
, flags
);
268 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats
);
270 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
271 * and the sysfs version makes coldplug work too.
274 static const struct spi_device_id
*spi_match_id(const struct spi_device_id
*id
,
275 const struct spi_device
*sdev
)
277 while (id
->name
[0]) {
278 if (!strcmp(sdev
->modalias
, id
->name
))
285 const struct spi_device_id
*spi_get_device_id(const struct spi_device
*sdev
)
287 const struct spi_driver
*sdrv
= to_spi_driver(sdev
->dev
.driver
);
289 return spi_match_id(sdrv
->id_table
, sdev
);
291 EXPORT_SYMBOL_GPL(spi_get_device_id
);
293 static int spi_match_device(struct device
*dev
, struct device_driver
*drv
)
295 const struct spi_device
*spi
= to_spi_device(dev
);
296 const struct spi_driver
*sdrv
= to_spi_driver(drv
);
298 /* Attempt an OF style match */
299 if (of_driver_match_device(dev
, drv
))
303 if (acpi_driver_match_device(dev
, drv
))
307 return !!spi_match_id(sdrv
->id_table
, spi
);
309 return strcmp(spi
->modalias
, drv
->name
) == 0;
312 static int spi_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
314 const struct spi_device
*spi
= to_spi_device(dev
);
317 rc
= acpi_device_uevent_modalias(dev
, env
);
321 add_uevent_var(env
, "MODALIAS=%s%s", SPI_MODULE_PREFIX
, spi
->modalias
);
325 struct bus_type spi_bus_type
= {
327 .dev_groups
= spi_dev_groups
,
328 .match
= spi_match_device
,
329 .uevent
= spi_uevent
,
331 EXPORT_SYMBOL_GPL(spi_bus_type
);
334 static int spi_drv_probe(struct device
*dev
)
336 const struct spi_driver
*sdrv
= to_spi_driver(dev
->driver
);
337 struct spi_device
*spi
= to_spi_device(dev
);
340 ret
= of_clk_set_defaults(dev
->of_node
, false);
345 spi
->irq
= of_irq_get(dev
->of_node
, 0);
346 if (spi
->irq
== -EPROBE_DEFER
)
347 return -EPROBE_DEFER
;
352 ret
= dev_pm_domain_attach(dev
, true);
353 if (ret
!= -EPROBE_DEFER
) {
354 ret
= sdrv
->probe(spi
);
356 dev_pm_domain_detach(dev
, true);
362 static int spi_drv_remove(struct device
*dev
)
364 const struct spi_driver
*sdrv
= to_spi_driver(dev
->driver
);
367 ret
= sdrv
->remove(to_spi_device(dev
));
368 dev_pm_domain_detach(dev
, true);
373 static void spi_drv_shutdown(struct device
*dev
)
375 const struct spi_driver
*sdrv
= to_spi_driver(dev
->driver
);
377 sdrv
->shutdown(to_spi_device(dev
));
381 * __spi_register_driver - register a SPI driver
382 * @owner: owner module of the driver to register
383 * @sdrv: the driver to register
386 * Return: zero on success, else a negative error code.
388 int __spi_register_driver(struct module
*owner
, struct spi_driver
*sdrv
)
390 sdrv
->driver
.owner
= owner
;
391 sdrv
->driver
.bus
= &spi_bus_type
;
393 sdrv
->driver
.probe
= spi_drv_probe
;
395 sdrv
->driver
.remove
= spi_drv_remove
;
397 sdrv
->driver
.shutdown
= spi_drv_shutdown
;
398 return driver_register(&sdrv
->driver
);
400 EXPORT_SYMBOL_GPL(__spi_register_driver
);
402 /*-------------------------------------------------------------------------*/
404 /* SPI devices should normally not be created by SPI device drivers; that
405 * would make them board-specific. Similarly with SPI master drivers.
406 * Device registration normally goes into like arch/.../mach.../board-YYY.c
407 * with other readonly (flashable) information about mainboard devices.
411 struct list_head list
;
412 struct spi_board_info board_info
;
415 static LIST_HEAD(board_list
);
416 static LIST_HEAD(spi_master_list
);
419 * Used to protect add/del opertion for board_info list and
420 * spi_master list, and their matching process
422 static DEFINE_MUTEX(board_lock
);
425 * spi_alloc_device - Allocate a new SPI device
426 * @master: Controller to which device is connected
429 * Allows a driver to allocate and initialize a spi_device without
430 * registering it immediately. This allows a driver to directly
431 * fill the spi_device with device parameters before calling
432 * spi_add_device() on it.
434 * Caller is responsible to call spi_add_device() on the returned
435 * spi_device structure to add it to the SPI master. If the caller
436 * needs to discard the spi_device without adding it, then it should
437 * call spi_dev_put() on it.
439 * Return: a pointer to the new device, or NULL.
441 struct spi_device
*spi_alloc_device(struct spi_master
*master
)
443 struct spi_device
*spi
;
445 if (!spi_master_get(master
))
448 spi
= kzalloc(sizeof(*spi
), GFP_KERNEL
);
450 spi_master_put(master
);
454 spi
->master
= master
;
455 spi
->dev
.parent
= &master
->dev
;
456 spi
->dev
.bus
= &spi_bus_type
;
457 spi
->dev
.release
= spidev_release
;
458 spi
->cs_gpio
= -ENOENT
;
460 spin_lock_init(&spi
->statistics
.lock
);
462 device_initialize(&spi
->dev
);
465 EXPORT_SYMBOL_GPL(spi_alloc_device
);
467 static void spi_dev_set_name(struct spi_device
*spi
)
469 struct acpi_device
*adev
= ACPI_COMPANION(&spi
->dev
);
472 dev_set_name(&spi
->dev
, "spi-%s", acpi_dev_name(adev
));
476 dev_set_name(&spi
->dev
, "%s.%u", dev_name(&spi
->master
->dev
),
480 static int spi_dev_check(struct device
*dev
, void *data
)
482 struct spi_device
*spi
= to_spi_device(dev
);
483 struct spi_device
*new_spi
= data
;
485 if (spi
->master
== new_spi
->master
&&
486 spi
->chip_select
== new_spi
->chip_select
)
492 * spi_add_device - Add spi_device allocated with spi_alloc_device
493 * @spi: spi_device to register
495 * Companion function to spi_alloc_device. Devices allocated with
496 * spi_alloc_device can be added onto the spi bus with this function.
498 * Return: 0 on success; negative errno on failure
500 int spi_add_device(struct spi_device
*spi
)
502 static DEFINE_MUTEX(spi_add_lock
);
503 struct spi_master
*master
= spi
->master
;
504 struct device
*dev
= master
->dev
.parent
;
507 /* Chipselects are numbered 0..max; validate. */
508 if (spi
->chip_select
>= master
->num_chipselect
) {
509 dev_err(dev
, "cs%d >= max %d\n",
511 master
->num_chipselect
);
515 /* Set the bus ID string */
516 spi_dev_set_name(spi
);
518 /* We need to make sure there's no other device with this
519 * chipselect **BEFORE** we call setup(), else we'll trash
520 * its configuration. Lock against concurrent add() calls.
522 mutex_lock(&spi_add_lock
);
524 status
= bus_for_each_dev(&spi_bus_type
, NULL
, spi
, spi_dev_check
);
526 dev_err(dev
, "chipselect %d already in use\n",
531 if (master
->cs_gpios
)
532 spi
->cs_gpio
= master
->cs_gpios
[spi
->chip_select
];
534 /* Drivers may modify this initial i/o setup, but will
535 * normally rely on the device being setup. Devices
536 * using SPI_CS_HIGH can't coexist well otherwise...
538 status
= spi_setup(spi
);
540 dev_err(dev
, "can't setup %s, status %d\n",
541 dev_name(&spi
->dev
), status
);
545 /* Device may be bound to an active driver when this returns */
546 status
= device_add(&spi
->dev
);
548 dev_err(dev
, "can't add %s, status %d\n",
549 dev_name(&spi
->dev
), status
);
551 dev_dbg(dev
, "registered child %s\n", dev_name(&spi
->dev
));
554 mutex_unlock(&spi_add_lock
);
557 EXPORT_SYMBOL_GPL(spi_add_device
);
560 * spi_new_device - instantiate one new SPI device
561 * @master: Controller to which device is connected
562 * @chip: Describes the SPI device
565 * On typical mainboards, this is purely internal; and it's not needed
566 * after board init creates the hard-wired devices. Some development
567 * platforms may not be able to use spi_register_board_info though, and
568 * this is exported so that for example a USB or parport based adapter
569 * driver could add devices (which it would learn about out-of-band).
571 * Return: the new device, or NULL.
573 struct spi_device
*spi_new_device(struct spi_master
*master
,
574 struct spi_board_info
*chip
)
576 struct spi_device
*proxy
;
579 /* NOTE: caller did any chip->bus_num checks necessary.
581 * Also, unless we change the return value convention to use
582 * error-or-pointer (not NULL-or-pointer), troubleshootability
583 * suggests syslogged diagnostics are best here (ugh).
586 proxy
= spi_alloc_device(master
);
590 WARN_ON(strlen(chip
->modalias
) >= sizeof(proxy
->modalias
));
592 proxy
->chip_select
= chip
->chip_select
;
593 proxy
->max_speed_hz
= chip
->max_speed_hz
;
594 proxy
->mode
= chip
->mode
;
595 proxy
->irq
= chip
->irq
;
596 strlcpy(proxy
->modalias
, chip
->modalias
, sizeof(proxy
->modalias
));
597 proxy
->dev
.platform_data
= (void *) chip
->platform_data
;
598 proxy
->controller_data
= chip
->controller_data
;
599 proxy
->controller_state
= NULL
;
601 status
= spi_add_device(proxy
);
609 EXPORT_SYMBOL_GPL(spi_new_device
);
612 * spi_unregister_device - unregister a single SPI device
613 * @spi: spi_device to unregister
615 * Start making the passed SPI device vanish. Normally this would be handled
616 * by spi_unregister_master().
618 void spi_unregister_device(struct spi_device
*spi
)
623 if (spi
->dev
.of_node
)
624 of_node_clear_flag(spi
->dev
.of_node
, OF_POPULATED
);
625 device_unregister(&spi
->dev
);
627 EXPORT_SYMBOL_GPL(spi_unregister_device
);
629 static void spi_match_master_to_boardinfo(struct spi_master
*master
,
630 struct spi_board_info
*bi
)
632 struct spi_device
*dev
;
634 if (master
->bus_num
!= bi
->bus_num
)
637 dev
= spi_new_device(master
, bi
);
639 dev_err(master
->dev
.parent
, "can't create new device for %s\n",
644 * spi_register_board_info - register SPI devices for a given board
645 * @info: array of chip descriptors
646 * @n: how many descriptors are provided
649 * Board-specific early init code calls this (probably during arch_initcall)
650 * with segments of the SPI device table. Any device nodes are created later,
651 * after the relevant parent SPI controller (bus_num) is defined. We keep
652 * this table of devices forever, so that reloading a controller driver will
653 * not make Linux forget about these hard-wired devices.
655 * Other code can also call this, e.g. a particular add-on board might provide
656 * SPI devices through its expansion connector, so code initializing that board
657 * would naturally declare its SPI devices.
659 * The board info passed can safely be __initdata ... but be careful of
660 * any embedded pointers (platform_data, etc), they're copied as-is.
662 * Return: zero on success, else a negative error code.
664 int spi_register_board_info(struct spi_board_info
const *info
, unsigned n
)
666 struct boardinfo
*bi
;
672 bi
= kzalloc(n
* sizeof(*bi
), GFP_KERNEL
);
676 for (i
= 0; i
< n
; i
++, bi
++, info
++) {
677 struct spi_master
*master
;
679 memcpy(&bi
->board_info
, info
, sizeof(*info
));
680 mutex_lock(&board_lock
);
681 list_add_tail(&bi
->list
, &board_list
);
682 list_for_each_entry(master
, &spi_master_list
, list
)
683 spi_match_master_to_boardinfo(master
, &bi
->board_info
);
684 mutex_unlock(&board_lock
);
690 /*-------------------------------------------------------------------------*/
692 static void spi_set_cs(struct spi_device
*spi
, bool enable
)
694 if (spi
->mode
& SPI_CS_HIGH
)
697 if (gpio_is_valid(spi
->cs_gpio
))
698 gpio_set_value(spi
->cs_gpio
, !enable
);
699 else if (spi
->master
->set_cs
)
700 spi
->master
->set_cs(spi
, !enable
);
703 #ifdef CONFIG_HAS_DMA
704 static int spi_map_buf(struct spi_master
*master
, struct device
*dev
,
705 struct sg_table
*sgt
, void *buf
, size_t len
,
706 enum dma_data_direction dir
)
708 const bool vmalloced_buf
= is_vmalloc_addr(buf
);
709 unsigned int max_seg_size
= dma_get_max_seg_size(dev
);
712 struct page
*vm_page
;
718 desc_len
= min_t(int, max_seg_size
, PAGE_SIZE
);
719 sgs
= DIV_ROUND_UP(len
+ offset_in_page(buf
), desc_len
);
720 } else if (virt_addr_valid(buf
)) {
721 desc_len
= min_t(int, max_seg_size
, master
->max_dma_len
);
722 sgs
= DIV_ROUND_UP(len
, desc_len
);
727 ret
= sg_alloc_table(sgt
, sgs
, GFP_KERNEL
);
731 for (i
= 0; i
< sgs
; i
++) {
735 len
, desc_len
- offset_in_page(buf
));
736 vm_page
= vmalloc_to_page(buf
);
741 sg_set_page(&sgt
->sgl
[i
], vm_page
,
742 min
, offset_in_page(buf
));
744 min
= min_t(size_t, len
, desc_len
);
746 sg_set_buf(&sgt
->sgl
[i
], sg_buf
, min
);
753 ret
= dma_map_sg(dev
, sgt
->sgl
, sgt
->nents
, dir
);
766 static void spi_unmap_buf(struct spi_master
*master
, struct device
*dev
,
767 struct sg_table
*sgt
, enum dma_data_direction dir
)
769 if (sgt
->orig_nents
) {
770 dma_unmap_sg(dev
, sgt
->sgl
, sgt
->orig_nents
, dir
);
775 static int __spi_map_msg(struct spi_master
*master
, struct spi_message
*msg
)
777 struct device
*tx_dev
, *rx_dev
;
778 struct spi_transfer
*xfer
;
781 if (!master
->can_dma
)
785 tx_dev
= master
->dma_tx
->device
->dev
;
787 tx_dev
= &master
->dev
;
790 rx_dev
= master
->dma_rx
->device
->dev
;
792 rx_dev
= &master
->dev
;
794 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
795 if (!master
->can_dma(master
, msg
->spi
, xfer
))
798 if (xfer
->tx_buf
!= NULL
) {
799 ret
= spi_map_buf(master
, tx_dev
, &xfer
->tx_sg
,
800 (void *)xfer
->tx_buf
, xfer
->len
,
806 if (xfer
->rx_buf
!= NULL
) {
807 ret
= spi_map_buf(master
, rx_dev
, &xfer
->rx_sg
,
808 xfer
->rx_buf
, xfer
->len
,
811 spi_unmap_buf(master
, tx_dev
, &xfer
->tx_sg
,
818 master
->cur_msg_mapped
= true;
823 static int __spi_unmap_msg(struct spi_master
*master
, struct spi_message
*msg
)
825 struct spi_transfer
*xfer
;
826 struct device
*tx_dev
, *rx_dev
;
828 if (!master
->cur_msg_mapped
|| !master
->can_dma
)
832 tx_dev
= master
->dma_tx
->device
->dev
;
834 tx_dev
= &master
->dev
;
837 rx_dev
= master
->dma_rx
->device
->dev
;
839 rx_dev
= &master
->dev
;
841 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
842 if (!master
->can_dma(master
, msg
->spi
, xfer
))
845 spi_unmap_buf(master
, rx_dev
, &xfer
->rx_sg
, DMA_FROM_DEVICE
);
846 spi_unmap_buf(master
, tx_dev
, &xfer
->tx_sg
, DMA_TO_DEVICE
);
851 #else /* !CONFIG_HAS_DMA */
852 static inline int __spi_map_msg(struct spi_master
*master
,
853 struct spi_message
*msg
)
858 static inline int __spi_unmap_msg(struct spi_master
*master
,
859 struct spi_message
*msg
)
863 #endif /* !CONFIG_HAS_DMA */
865 static inline int spi_unmap_msg(struct spi_master
*master
,
866 struct spi_message
*msg
)
868 struct spi_transfer
*xfer
;
870 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
872 * Restore the original value of tx_buf or rx_buf if they are
875 if (xfer
->tx_buf
== master
->dummy_tx
)
877 if (xfer
->rx_buf
== master
->dummy_rx
)
881 return __spi_unmap_msg(master
, msg
);
884 static int spi_map_msg(struct spi_master
*master
, struct spi_message
*msg
)
886 struct spi_transfer
*xfer
;
888 unsigned int max_tx
, max_rx
;
890 if (master
->flags
& (SPI_MASTER_MUST_RX
| SPI_MASTER_MUST_TX
)) {
894 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
895 if ((master
->flags
& SPI_MASTER_MUST_TX
) &&
897 max_tx
= max(xfer
->len
, max_tx
);
898 if ((master
->flags
& SPI_MASTER_MUST_RX
) &&
900 max_rx
= max(xfer
->len
, max_rx
);
904 tmp
= krealloc(master
->dummy_tx
, max_tx
,
905 GFP_KERNEL
| GFP_DMA
);
908 master
->dummy_tx
= tmp
;
909 memset(tmp
, 0, max_tx
);
913 tmp
= krealloc(master
->dummy_rx
, max_rx
,
914 GFP_KERNEL
| GFP_DMA
);
917 master
->dummy_rx
= tmp
;
920 if (max_tx
|| max_rx
) {
921 list_for_each_entry(xfer
, &msg
->transfers
,
924 xfer
->tx_buf
= master
->dummy_tx
;
926 xfer
->rx_buf
= master
->dummy_rx
;
931 return __spi_map_msg(master
, msg
);
935 * spi_transfer_one_message - Default implementation of transfer_one_message()
937 * This is a standard implementation of transfer_one_message() for
938 * drivers which implement a transfer_one() operation. It provides
939 * standard handling of delays and chip select management.
941 static int spi_transfer_one_message(struct spi_master
*master
,
942 struct spi_message
*msg
)
944 struct spi_transfer
*xfer
;
945 bool keep_cs
= false;
947 unsigned long ms
= 1;
948 struct spi_statistics
*statm
= &master
->statistics
;
949 struct spi_statistics
*stats
= &msg
->spi
->statistics
;
951 spi_set_cs(msg
->spi
, true);
953 SPI_STATISTICS_INCREMENT_FIELD(statm
, messages
);
954 SPI_STATISTICS_INCREMENT_FIELD(stats
, messages
);
956 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
957 trace_spi_transfer_start(msg
, xfer
);
959 spi_statistics_add_transfer_stats(statm
, xfer
, master
);
960 spi_statistics_add_transfer_stats(stats
, xfer
, master
);
962 if (xfer
->tx_buf
|| xfer
->rx_buf
) {
963 reinit_completion(&master
->xfer_completion
);
965 ret
= master
->transfer_one(master
, msg
->spi
, xfer
);
967 SPI_STATISTICS_INCREMENT_FIELD(statm
,
969 SPI_STATISTICS_INCREMENT_FIELD(stats
,
971 dev_err(&msg
->spi
->dev
,
972 "SPI transfer failed: %d\n", ret
);
978 ms
= xfer
->len
* 8 * 1000 / xfer
->speed_hz
;
979 ms
+= ms
+ 100; /* some tolerance */
981 ms
= wait_for_completion_timeout(&master
->xfer_completion
,
982 msecs_to_jiffies(ms
));
986 SPI_STATISTICS_INCREMENT_FIELD(statm
,
988 SPI_STATISTICS_INCREMENT_FIELD(stats
,
990 dev_err(&msg
->spi
->dev
,
991 "SPI transfer timed out\n");
992 msg
->status
= -ETIMEDOUT
;
996 dev_err(&msg
->spi
->dev
,
997 "Bufferless transfer has length %u\n",
1001 trace_spi_transfer_stop(msg
, xfer
);
1003 if (msg
->status
!= -EINPROGRESS
)
1006 if (xfer
->delay_usecs
)
1007 udelay(xfer
->delay_usecs
);
1009 if (xfer
->cs_change
) {
1010 if (list_is_last(&xfer
->transfer_list
,
1014 spi_set_cs(msg
->spi
, false);
1016 spi_set_cs(msg
->spi
, true);
1020 msg
->actual_length
+= xfer
->len
;
1024 if (ret
!= 0 || !keep_cs
)
1025 spi_set_cs(msg
->spi
, false);
1027 if (msg
->status
== -EINPROGRESS
)
1030 if (msg
->status
&& master
->handle_err
)
1031 master
->handle_err(master
, msg
);
1033 spi_res_release(master
, msg
);
1035 spi_finalize_current_message(master
);
1041 * spi_finalize_current_transfer - report completion of a transfer
1042 * @master: the master reporting completion
1044 * Called by SPI drivers using the core transfer_one_message()
1045 * implementation to notify it that the current interrupt driven
1046 * transfer has finished and the next one may be scheduled.
1048 void spi_finalize_current_transfer(struct spi_master
*master
)
1050 complete(&master
->xfer_completion
);
1052 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer
);
1055 * __spi_pump_messages - function which processes spi message queue
1056 * @master: master to process queue for
1057 * @in_kthread: true if we are in the context of the message pump thread
1058 * @bus_locked: true if the bus mutex is held when calling this function
1060 * This function checks if there is any spi message in the queue that
1061 * needs processing and if so call out to the driver to initialize hardware
1062 * and transfer each message.
1064 * Note that it is called both from the kthread itself and also from
1065 * inside spi_sync(); the queue extraction handling at the top of the
1066 * function should deal with this safely.
1068 static void __spi_pump_messages(struct spi_master
*master
, bool in_kthread
,
1071 unsigned long flags
;
1072 bool was_busy
= false;
1076 spin_lock_irqsave(&master
->queue_lock
, flags
);
1078 /* Make sure we are not already running a message */
1079 if (master
->cur_msg
) {
1080 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1084 /* If another context is idling the device then defer */
1085 if (master
->idling
) {
1086 queue_kthread_work(&master
->kworker
, &master
->pump_messages
);
1087 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1091 /* Check if the queue is idle */
1092 if (list_empty(&master
->queue
) || !master
->running
) {
1093 if (!master
->busy
) {
1094 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1098 /* Only do teardown in the thread */
1100 queue_kthread_work(&master
->kworker
,
1101 &master
->pump_messages
);
1102 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1106 master
->busy
= false;
1107 master
->idling
= true;
1108 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1110 kfree(master
->dummy_rx
);
1111 master
->dummy_rx
= NULL
;
1112 kfree(master
->dummy_tx
);
1113 master
->dummy_tx
= NULL
;
1114 if (master
->unprepare_transfer_hardware
&&
1115 master
->unprepare_transfer_hardware(master
))
1116 dev_err(&master
->dev
,
1117 "failed to unprepare transfer hardware\n");
1118 if (master
->auto_runtime_pm
) {
1119 pm_runtime_mark_last_busy(master
->dev
.parent
);
1120 pm_runtime_put_autosuspend(master
->dev
.parent
);
1122 trace_spi_master_idle(master
);
1124 spin_lock_irqsave(&master
->queue_lock
, flags
);
1125 master
->idling
= false;
1126 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1130 /* Extract head of queue */
1132 list_first_entry(&master
->queue
, struct spi_message
, queue
);
1134 list_del_init(&master
->cur_msg
->queue
);
1138 master
->busy
= true;
1139 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1141 if (!was_busy
&& master
->auto_runtime_pm
) {
1142 ret
= pm_runtime_get_sync(master
->dev
.parent
);
1144 dev_err(&master
->dev
, "Failed to power device: %d\n",
1151 trace_spi_master_busy(master
);
1153 if (!was_busy
&& master
->prepare_transfer_hardware
) {
1154 ret
= master
->prepare_transfer_hardware(master
);
1156 dev_err(&master
->dev
,
1157 "failed to prepare transfer hardware\n");
1159 if (master
->auto_runtime_pm
)
1160 pm_runtime_put(master
->dev
.parent
);
1166 mutex_lock(&master
->bus_lock_mutex
);
1168 trace_spi_message_start(master
->cur_msg
);
1170 if (master
->prepare_message
) {
1171 ret
= master
->prepare_message(master
, master
->cur_msg
);
1173 dev_err(&master
->dev
,
1174 "failed to prepare message: %d\n", ret
);
1175 master
->cur_msg
->status
= ret
;
1176 spi_finalize_current_message(master
);
1179 master
->cur_msg_prepared
= true;
1182 ret
= spi_map_msg(master
, master
->cur_msg
);
1184 master
->cur_msg
->status
= ret
;
1185 spi_finalize_current_message(master
);
1189 ret
= master
->transfer_one_message(master
, master
->cur_msg
);
1191 dev_err(&master
->dev
,
1192 "failed to transfer one message from queue\n");
1198 mutex_unlock(&master
->bus_lock_mutex
);
1200 /* Prod the scheduler in case transfer_one() was busy waiting */
1206 * spi_pump_messages - kthread work function which processes spi message queue
1207 * @work: pointer to kthread work struct contained in the master struct
1209 static void spi_pump_messages(struct kthread_work
*work
)
1211 struct spi_master
*master
=
1212 container_of(work
, struct spi_master
, pump_messages
);
1214 __spi_pump_messages(master
, true, master
->bus_lock_flag
);
1217 static int spi_init_queue(struct spi_master
*master
)
1219 struct sched_param param
= { .sched_priority
= MAX_RT_PRIO
- 1 };
1221 master
->running
= false;
1222 master
->busy
= false;
1224 init_kthread_worker(&master
->kworker
);
1225 master
->kworker_task
= kthread_run(kthread_worker_fn
,
1226 &master
->kworker
, "%s",
1227 dev_name(&master
->dev
));
1228 if (IS_ERR(master
->kworker_task
)) {
1229 dev_err(&master
->dev
, "failed to create message pump task\n");
1230 return PTR_ERR(master
->kworker_task
);
1232 init_kthread_work(&master
->pump_messages
, spi_pump_messages
);
1235 * Master config will indicate if this controller should run the
1236 * message pump with high (realtime) priority to reduce the transfer
1237 * latency on the bus by minimising the delay between a transfer
1238 * request and the scheduling of the message pump thread. Without this
1239 * setting the message pump thread will remain at default priority.
1242 dev_info(&master
->dev
,
1243 "will run message pump with realtime priority\n");
1244 sched_setscheduler(master
->kworker_task
, SCHED_FIFO
, ¶m
);
1251 * spi_get_next_queued_message() - called by driver to check for queued
1253 * @master: the master to check for queued messages
1255 * If there are more messages in the queue, the next message is returned from
1258 * Return: the next message in the queue, else NULL if the queue is empty.
1260 struct spi_message
*spi_get_next_queued_message(struct spi_master
*master
)
1262 struct spi_message
*next
;
1263 unsigned long flags
;
1265 /* get a pointer to the next message, if any */
1266 spin_lock_irqsave(&master
->queue_lock
, flags
);
1267 next
= list_first_entry_or_null(&master
->queue
, struct spi_message
,
1269 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1273 EXPORT_SYMBOL_GPL(spi_get_next_queued_message
);
1276 * spi_finalize_current_message() - the current message is complete
1277 * @master: the master to return the message to
1279 * Called by the driver to notify the core that the message in the front of the
1280 * queue is complete and can be removed from the queue.
1282 void spi_finalize_current_message(struct spi_master
*master
)
1284 struct spi_message
*mesg
;
1285 unsigned long flags
;
1288 spin_lock_irqsave(&master
->queue_lock
, flags
);
1289 mesg
= master
->cur_msg
;
1290 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1292 spi_unmap_msg(master
, mesg
);
1294 if (master
->cur_msg_prepared
&& master
->unprepare_message
) {
1295 ret
= master
->unprepare_message(master
, mesg
);
1297 dev_err(&master
->dev
,
1298 "failed to unprepare message: %d\n", ret
);
1302 spin_lock_irqsave(&master
->queue_lock
, flags
);
1303 master
->cur_msg
= NULL
;
1304 master
->cur_msg_prepared
= false;
1305 queue_kthread_work(&master
->kworker
, &master
->pump_messages
);
1306 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1308 trace_spi_message_done(mesg
);
1312 mesg
->complete(mesg
->context
);
1314 EXPORT_SYMBOL_GPL(spi_finalize_current_message
);
1316 static int spi_start_queue(struct spi_master
*master
)
1318 unsigned long flags
;
1320 spin_lock_irqsave(&master
->queue_lock
, flags
);
1322 if (master
->running
|| master
->busy
) {
1323 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1327 master
->running
= true;
1328 master
->cur_msg
= NULL
;
1329 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1331 queue_kthread_work(&master
->kworker
, &master
->pump_messages
);
1336 static int spi_stop_queue(struct spi_master
*master
)
1338 unsigned long flags
;
1339 unsigned limit
= 500;
1342 spin_lock_irqsave(&master
->queue_lock
, flags
);
1345 * This is a bit lame, but is optimized for the common execution path.
1346 * A wait_queue on the master->busy could be used, but then the common
1347 * execution path (pump_messages) would be required to call wake_up or
1348 * friends on every SPI message. Do this instead.
1350 while ((!list_empty(&master
->queue
) || master
->busy
) && limit
--) {
1351 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1352 usleep_range(10000, 11000);
1353 spin_lock_irqsave(&master
->queue_lock
, flags
);
1356 if (!list_empty(&master
->queue
) || master
->busy
)
1359 master
->running
= false;
1361 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1364 dev_warn(&master
->dev
,
1365 "could not stop message queue\n");
1371 static int spi_destroy_queue(struct spi_master
*master
)
1375 ret
= spi_stop_queue(master
);
1378 * flush_kthread_worker will block until all work is done.
1379 * If the reason that stop_queue timed out is that the work will never
1380 * finish, then it does no good to call flush/stop thread, so
1384 dev_err(&master
->dev
, "problem destroying queue\n");
1388 flush_kthread_worker(&master
->kworker
);
1389 kthread_stop(master
->kworker_task
);
1394 static int __spi_queued_transfer(struct spi_device
*spi
,
1395 struct spi_message
*msg
,
1398 struct spi_master
*master
= spi
->master
;
1399 unsigned long flags
;
1401 spin_lock_irqsave(&master
->queue_lock
, flags
);
1403 if (!master
->running
) {
1404 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1407 msg
->actual_length
= 0;
1408 msg
->status
= -EINPROGRESS
;
1410 list_add_tail(&msg
->queue
, &master
->queue
);
1411 if (!master
->busy
&& need_pump
)
1412 queue_kthread_work(&master
->kworker
, &master
->pump_messages
);
1414 spin_unlock_irqrestore(&master
->queue_lock
, flags
);
1419 * spi_queued_transfer - transfer function for queued transfers
1420 * @spi: spi device which is requesting transfer
1421 * @msg: spi message which is to handled is queued to driver queue
1423 * Return: zero on success, else a negative error code.
1425 static int spi_queued_transfer(struct spi_device
*spi
, struct spi_message
*msg
)
1427 return __spi_queued_transfer(spi
, msg
, true);
1430 static int spi_master_initialize_queue(struct spi_master
*master
)
1434 master
->transfer
= spi_queued_transfer
;
1435 if (!master
->transfer_one_message
)
1436 master
->transfer_one_message
= spi_transfer_one_message
;
1438 /* Initialize and start queue */
1439 ret
= spi_init_queue(master
);
1441 dev_err(&master
->dev
, "problem initializing queue\n");
1442 goto err_init_queue
;
1444 master
->queued
= true;
1445 ret
= spi_start_queue(master
);
1447 dev_err(&master
->dev
, "problem starting queue\n");
1448 goto err_start_queue
;
1454 spi_destroy_queue(master
);
1459 /*-------------------------------------------------------------------------*/
1461 #if defined(CONFIG_OF)
1462 static struct spi_device
*
1463 of_register_spi_device(struct spi_master
*master
, struct device_node
*nc
)
1465 struct spi_device
*spi
;
1469 /* Alloc an spi_device */
1470 spi
= spi_alloc_device(master
);
1472 dev_err(&master
->dev
, "spi_device alloc error for %s\n",
1478 /* Select device driver */
1479 rc
= of_modalias_node(nc
, spi
->modalias
,
1480 sizeof(spi
->modalias
));
1482 dev_err(&master
->dev
, "cannot find modalias for %s\n",
1487 /* Device address */
1488 rc
= of_property_read_u32(nc
, "reg", &value
);
1490 dev_err(&master
->dev
, "%s has no valid 'reg' property (%d)\n",
1494 spi
->chip_select
= value
;
1496 /* Mode (clock phase/polarity/etc.) */
1497 if (of_find_property(nc
, "spi-cpha", NULL
))
1498 spi
->mode
|= SPI_CPHA
;
1499 if (of_find_property(nc
, "spi-cpol", NULL
))
1500 spi
->mode
|= SPI_CPOL
;
1501 if (of_find_property(nc
, "spi-cs-high", NULL
))
1502 spi
->mode
|= SPI_CS_HIGH
;
1503 if (of_find_property(nc
, "spi-3wire", NULL
))
1504 spi
->mode
|= SPI_3WIRE
;
1505 if (of_find_property(nc
, "spi-lsb-first", NULL
))
1506 spi
->mode
|= SPI_LSB_FIRST
;
1508 /* Device DUAL/QUAD mode */
1509 if (!of_property_read_u32(nc
, "spi-tx-bus-width", &value
)) {
1514 spi
->mode
|= SPI_TX_DUAL
;
1517 spi
->mode
|= SPI_TX_QUAD
;
1520 dev_warn(&master
->dev
,
1521 "spi-tx-bus-width %d not supported\n",
1527 if (!of_property_read_u32(nc
, "spi-rx-bus-width", &value
)) {
1532 spi
->mode
|= SPI_RX_DUAL
;
1535 spi
->mode
|= SPI_RX_QUAD
;
1538 dev_warn(&master
->dev
,
1539 "spi-rx-bus-width %d not supported\n",
1546 rc
= of_property_read_u32(nc
, "spi-max-frequency", &value
);
1548 dev_err(&master
->dev
, "%s has no valid 'spi-max-frequency' property (%d)\n",
1552 spi
->max_speed_hz
= value
;
1554 /* Store a pointer to the node in the device structure */
1556 spi
->dev
.of_node
= nc
;
1558 /* Register the new device */
1559 rc
= spi_add_device(spi
);
1561 dev_err(&master
->dev
, "spi_device register error %s\n",
1574 * of_register_spi_devices() - Register child devices onto the SPI bus
1575 * @master: Pointer to spi_master device
1577 * Registers an spi_device for each child node of master node which has a 'reg'
1580 static void of_register_spi_devices(struct spi_master
*master
)
1582 struct spi_device
*spi
;
1583 struct device_node
*nc
;
1585 if (!master
->dev
.of_node
)
1588 for_each_available_child_of_node(master
->dev
.of_node
, nc
) {
1589 if (of_node_test_and_set_flag(nc
, OF_POPULATED
))
1591 spi
= of_register_spi_device(master
, nc
);
1593 dev_warn(&master
->dev
, "Failed to create SPI device for %s\n",
1598 static void of_register_spi_devices(struct spi_master
*master
) { }
1602 static int acpi_spi_add_resource(struct acpi_resource
*ares
, void *data
)
1604 struct spi_device
*spi
= data
;
1605 struct spi_master
*master
= spi
->master
;
1607 if (ares
->type
== ACPI_RESOURCE_TYPE_SERIAL_BUS
) {
1608 struct acpi_resource_spi_serialbus
*sb
;
1610 sb
= &ares
->data
.spi_serial_bus
;
1611 if (sb
->type
== ACPI_RESOURCE_SERIAL_TYPE_SPI
) {
1613 * ACPI DeviceSelection numbering is handled by the
1614 * host controller driver in Windows and can vary
1615 * from driver to driver. In Linux we always expect
1616 * 0 .. max - 1 so we need to ask the driver to
1617 * translate between the two schemes.
1619 if (master
->fw_translate_cs
) {
1620 int cs
= master
->fw_translate_cs(master
,
1621 sb
->device_selection
);
1624 spi
->chip_select
= cs
;
1626 spi
->chip_select
= sb
->device_selection
;
1629 spi
->max_speed_hz
= sb
->connection_speed
;
1631 if (sb
->clock_phase
== ACPI_SPI_SECOND_PHASE
)
1632 spi
->mode
|= SPI_CPHA
;
1633 if (sb
->clock_polarity
== ACPI_SPI_START_HIGH
)
1634 spi
->mode
|= SPI_CPOL
;
1635 if (sb
->device_polarity
== ACPI_SPI_ACTIVE_HIGH
)
1636 spi
->mode
|= SPI_CS_HIGH
;
1638 } else if (spi
->irq
< 0) {
1641 if (acpi_dev_resource_interrupt(ares
, 0, &r
))
1645 /* Always tell the ACPI core to skip this resource */
1649 static acpi_status
acpi_spi_add_device(acpi_handle handle
, u32 level
,
1650 void *data
, void **return_value
)
1652 struct spi_master
*master
= data
;
1653 struct list_head resource_list
;
1654 struct acpi_device
*adev
;
1655 struct spi_device
*spi
;
1658 if (acpi_bus_get_device(handle
, &adev
))
1660 if (acpi_bus_get_status(adev
) || !adev
->status
.present
)
1663 spi
= spi_alloc_device(master
);
1665 dev_err(&master
->dev
, "failed to allocate SPI device for %s\n",
1666 dev_name(&adev
->dev
));
1667 return AE_NO_MEMORY
;
1670 ACPI_COMPANION_SET(&spi
->dev
, adev
);
1673 INIT_LIST_HEAD(&resource_list
);
1674 ret
= acpi_dev_get_resources(adev
, &resource_list
,
1675 acpi_spi_add_resource
, spi
);
1676 acpi_dev_free_resource_list(&resource_list
);
1678 if (ret
< 0 || !spi
->max_speed_hz
) {
1684 spi
->irq
= acpi_dev_gpio_irq_get(adev
, 0);
1686 adev
->power
.flags
.ignore_parent
= true;
1687 strlcpy(spi
->modalias
, acpi_device_hid(adev
), sizeof(spi
->modalias
));
1688 if (spi_add_device(spi
)) {
1689 adev
->power
.flags
.ignore_parent
= false;
1690 dev_err(&master
->dev
, "failed to add SPI device %s from ACPI\n",
1691 dev_name(&adev
->dev
));
1698 static void acpi_register_spi_devices(struct spi_master
*master
)
1703 handle
= ACPI_HANDLE(master
->dev
.parent
);
1707 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, handle
, 1,
1708 acpi_spi_add_device
, NULL
,
1710 if (ACPI_FAILURE(status
))
1711 dev_warn(&master
->dev
, "failed to enumerate SPI slaves\n");
1714 static inline void acpi_register_spi_devices(struct spi_master
*master
) {}
1715 #endif /* CONFIG_ACPI */
1717 static void spi_master_release(struct device
*dev
)
1719 struct spi_master
*master
;
1721 master
= container_of(dev
, struct spi_master
, dev
);
1725 static struct class spi_master_class
= {
1726 .name
= "spi_master",
1727 .owner
= THIS_MODULE
,
1728 .dev_release
= spi_master_release
,
1729 .dev_groups
= spi_master_groups
,
1734 * spi_alloc_master - allocate SPI master controller
1735 * @dev: the controller, possibly using the platform_bus
1736 * @size: how much zeroed driver-private data to allocate; the pointer to this
1737 * memory is in the driver_data field of the returned device,
1738 * accessible with spi_master_get_devdata().
1739 * Context: can sleep
1741 * This call is used only by SPI master controller drivers, which are the
1742 * only ones directly touching chip registers. It's how they allocate
1743 * an spi_master structure, prior to calling spi_register_master().
1745 * This must be called from context that can sleep.
1747 * The caller is responsible for assigning the bus number and initializing
1748 * the master's methods before calling spi_register_master(); and (after errors
1749 * adding the device) calling spi_master_put() to prevent a memory leak.
1751 * Return: the SPI master structure on success, else NULL.
1753 struct spi_master
*spi_alloc_master(struct device
*dev
, unsigned size
)
1755 struct spi_master
*master
;
1760 master
= kzalloc(size
+ sizeof(*master
), GFP_KERNEL
);
1764 device_initialize(&master
->dev
);
1765 master
->bus_num
= -1;
1766 master
->num_chipselect
= 1;
1767 master
->dev
.class = &spi_master_class
;
1768 master
->dev
.parent
= dev
;
1769 pm_suspend_ignore_children(&master
->dev
, true);
1770 spi_master_set_devdata(master
, &master
[1]);
1774 EXPORT_SYMBOL_GPL(spi_alloc_master
);
1777 static int of_spi_register_master(struct spi_master
*master
)
1780 struct device_node
*np
= master
->dev
.of_node
;
1785 nb
= of_gpio_named_count(np
, "cs-gpios");
1786 master
->num_chipselect
= max_t(int, nb
, master
->num_chipselect
);
1788 /* Return error only for an incorrectly formed cs-gpios property */
1789 if (nb
== 0 || nb
== -ENOENT
)
1794 cs
= devm_kzalloc(&master
->dev
,
1795 sizeof(int) * master
->num_chipselect
,
1797 master
->cs_gpios
= cs
;
1799 if (!master
->cs_gpios
)
1802 for (i
= 0; i
< master
->num_chipselect
; i
++)
1805 for (i
= 0; i
< nb
; i
++)
1806 cs
[i
] = of_get_named_gpio(np
, "cs-gpios", i
);
1811 static int of_spi_register_master(struct spi_master
*master
)
1818 * spi_register_master - register SPI master controller
1819 * @master: initialized master, originally from spi_alloc_master()
1820 * Context: can sleep
1822 * SPI master controllers connect to their drivers using some non-SPI bus,
1823 * such as the platform bus. The final stage of probe() in that code
1824 * includes calling spi_register_master() to hook up to this SPI bus glue.
1826 * SPI controllers use board specific (often SOC specific) bus numbers,
1827 * and board-specific addressing for SPI devices combines those numbers
1828 * with chip select numbers. Since SPI does not directly support dynamic
1829 * device identification, boards need configuration tables telling which
1830 * chip is at which address.
1832 * This must be called from context that can sleep. It returns zero on
1833 * success, else a negative error code (dropping the master's refcount).
1834 * After a successful return, the caller is responsible for calling
1835 * spi_unregister_master().
1837 * Return: zero on success, else a negative error code.
1839 int spi_register_master(struct spi_master
*master
)
1841 static atomic_t dyn_bus_id
= ATOMIC_INIT((1<<15) - 1);
1842 struct device
*dev
= master
->dev
.parent
;
1843 struct boardinfo
*bi
;
1844 int status
= -ENODEV
;
1850 status
= of_spi_register_master(master
);
1854 /* even if it's just one always-selected device, there must
1855 * be at least one chipselect
1857 if (master
->num_chipselect
== 0)
1860 if ((master
->bus_num
< 0) && master
->dev
.of_node
)
1861 master
->bus_num
= of_alias_get_id(master
->dev
.of_node
, "spi");
1863 /* convention: dynamically assigned bus IDs count down from the max */
1864 if (master
->bus_num
< 0) {
1865 /* FIXME switch to an IDR based scheme, something like
1866 * I2C now uses, so we can't run out of "dynamic" IDs
1868 master
->bus_num
= atomic_dec_return(&dyn_bus_id
);
1872 INIT_LIST_HEAD(&master
->queue
);
1873 spin_lock_init(&master
->queue_lock
);
1874 spin_lock_init(&master
->bus_lock_spinlock
);
1875 mutex_init(&master
->bus_lock_mutex
);
1876 master
->bus_lock_flag
= 0;
1877 init_completion(&master
->xfer_completion
);
1878 if (!master
->max_dma_len
)
1879 master
->max_dma_len
= INT_MAX
;
1881 /* register the device, then userspace will see it.
1882 * registration fails if the bus ID is in use.
1884 dev_set_name(&master
->dev
, "spi%u", master
->bus_num
);
1885 status
= device_add(&master
->dev
);
1888 dev_dbg(dev
, "registered master %s%s\n", dev_name(&master
->dev
),
1889 dynamic
? " (dynamic)" : "");
1891 /* If we're using a queued driver, start the queue */
1892 if (master
->transfer
)
1893 dev_info(dev
, "master is unqueued, this is deprecated\n");
1895 status
= spi_master_initialize_queue(master
);
1897 device_del(&master
->dev
);
1901 /* add statistics */
1902 spin_lock_init(&master
->statistics
.lock
);
1904 mutex_lock(&board_lock
);
1905 list_add_tail(&master
->list
, &spi_master_list
);
1906 list_for_each_entry(bi
, &board_list
, list
)
1907 spi_match_master_to_boardinfo(master
, &bi
->board_info
);
1908 mutex_unlock(&board_lock
);
1910 /* Register devices from the device tree and ACPI */
1911 of_register_spi_devices(master
);
1912 acpi_register_spi_devices(master
);
1916 EXPORT_SYMBOL_GPL(spi_register_master
);
1918 static void devm_spi_unregister(struct device
*dev
, void *res
)
1920 spi_unregister_master(*(struct spi_master
**)res
);
1924 * dev_spi_register_master - register managed SPI master controller
1925 * @dev: device managing SPI master
1926 * @master: initialized master, originally from spi_alloc_master()
1927 * Context: can sleep
1929 * Register a SPI device as with spi_register_master() which will
1930 * automatically be unregister
1932 * Return: zero on success, else a negative error code.
1934 int devm_spi_register_master(struct device
*dev
, struct spi_master
*master
)
1936 struct spi_master
**ptr
;
1939 ptr
= devres_alloc(devm_spi_unregister
, sizeof(*ptr
), GFP_KERNEL
);
1943 ret
= spi_register_master(master
);
1946 devres_add(dev
, ptr
);
1953 EXPORT_SYMBOL_GPL(devm_spi_register_master
);
1955 static int __unregister(struct device
*dev
, void *null
)
1957 spi_unregister_device(to_spi_device(dev
));
1962 * spi_unregister_master - unregister SPI master controller
1963 * @master: the master being unregistered
1964 * Context: can sleep
1966 * This call is used only by SPI master controller drivers, which are the
1967 * only ones directly touching chip registers.
1969 * This must be called from context that can sleep.
1971 void spi_unregister_master(struct spi_master
*master
)
1975 if (master
->queued
) {
1976 if (spi_destroy_queue(master
))
1977 dev_err(&master
->dev
, "queue remove failed\n");
1980 mutex_lock(&board_lock
);
1981 list_del(&master
->list
);
1982 mutex_unlock(&board_lock
);
1984 dummy
= device_for_each_child(&master
->dev
, NULL
, __unregister
);
1985 device_unregister(&master
->dev
);
1987 EXPORT_SYMBOL_GPL(spi_unregister_master
);
1989 int spi_master_suspend(struct spi_master
*master
)
1993 /* Basically no-ops for non-queued masters */
1994 if (!master
->queued
)
1997 ret
= spi_stop_queue(master
);
1999 dev_err(&master
->dev
, "queue stop failed\n");
2003 EXPORT_SYMBOL_GPL(spi_master_suspend
);
2005 int spi_master_resume(struct spi_master
*master
)
2009 if (!master
->queued
)
2012 ret
= spi_start_queue(master
);
2014 dev_err(&master
->dev
, "queue restart failed\n");
2018 EXPORT_SYMBOL_GPL(spi_master_resume
);
2020 static int __spi_master_match(struct device
*dev
, const void *data
)
2022 struct spi_master
*m
;
2023 const u16
*bus_num
= data
;
2025 m
= container_of(dev
, struct spi_master
, dev
);
2026 return m
->bus_num
== *bus_num
;
2030 * spi_busnum_to_master - look up master associated with bus_num
2031 * @bus_num: the master's bus number
2032 * Context: can sleep
2034 * This call may be used with devices that are registered after
2035 * arch init time. It returns a refcounted pointer to the relevant
2036 * spi_master (which the caller must release), or NULL if there is
2037 * no such master registered.
2039 * Return: the SPI master structure on success, else NULL.
2041 struct spi_master
*spi_busnum_to_master(u16 bus_num
)
2044 struct spi_master
*master
= NULL
;
2046 dev
= class_find_device(&spi_master_class
, NULL
, &bus_num
,
2047 __spi_master_match
);
2049 master
= container_of(dev
, struct spi_master
, dev
);
2050 /* reference got in class_find_device */
2053 EXPORT_SYMBOL_GPL(spi_busnum_to_master
);
2055 /*-------------------------------------------------------------------------*/
2057 /* Core methods for SPI resource management */
2060 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2061 * during the processing of a spi_message while using
2063 * @spi: the spi device for which we allocate memory
2064 * @release: the release code to execute for this resource
2065 * @size: size to alloc and return
2066 * @gfp: GFP allocation flags
2068 * Return: the pointer to the allocated data
2070 * This may get enhanced in the future to allocate from a memory pool
2071 * of the @spi_device or @spi_master to avoid repeated allocations.
2073 void *spi_res_alloc(struct spi_device
*spi
,
2074 spi_res_release_t release
,
2075 size_t size
, gfp_t gfp
)
2077 struct spi_res
*sres
;
2079 sres
= kzalloc(sizeof(*sres
) + size
, gfp
);
2083 INIT_LIST_HEAD(&sres
->entry
);
2084 sres
->release
= release
;
2088 EXPORT_SYMBOL_GPL(spi_res_alloc
);
2091 * spi_res_free - free an spi resource
2092 * @res: pointer to the custom data of a resource
2095 void spi_res_free(void *res
)
2097 struct spi_res
*sres
= container_of(res
, struct spi_res
, data
);
2102 WARN_ON(!list_empty(&sres
->entry
));
2105 EXPORT_SYMBOL_GPL(spi_res_free
);
2108 * spi_res_add - add a spi_res to the spi_message
2109 * @message: the spi message
2110 * @res: the spi_resource
2112 void spi_res_add(struct spi_message
*message
, void *res
)
2114 struct spi_res
*sres
= container_of(res
, struct spi_res
, data
);
2116 WARN_ON(!list_empty(&sres
->entry
));
2117 list_add_tail(&sres
->entry
, &message
->resources
);
2119 EXPORT_SYMBOL_GPL(spi_res_add
);
2122 * spi_res_release - release all spi resources for this message
2123 * @master: the @spi_master
2124 * @message: the @spi_message
2126 void spi_res_release(struct spi_master
*master
,
2127 struct spi_message
*message
)
2129 struct spi_res
*res
;
2131 while (!list_empty(&message
->resources
)) {
2132 res
= list_last_entry(&message
->resources
,
2133 struct spi_res
, entry
);
2136 res
->release(master
, message
, res
->data
);
2138 list_del(&res
->entry
);
2143 EXPORT_SYMBOL_GPL(spi_res_release
);
2145 /*-------------------------------------------------------------------------*/
2147 /* Core methods for spi_message alterations */
2149 static void __spi_replace_transfers_release(struct spi_master
*master
,
2150 struct spi_message
*msg
,
2153 struct spi_replaced_transfers
*rxfer
= res
;
2156 /* call extra callback if requested */
2158 rxfer
->release(master
, msg
, res
);
2160 /* insert replaced transfers back into the message */
2161 list_splice(&rxfer
->replaced_transfers
, rxfer
->replaced_after
);
2163 /* remove the formerly inserted entries */
2164 for (i
= 0; i
< rxfer
->inserted
; i
++)
2165 list_del(&rxfer
->inserted_transfers
[i
].transfer_list
);
2169 * spi_replace_transfers - replace transfers with several transfers
2170 * and register change with spi_message.resources
2171 * @msg: the spi_message we work upon
2172 * @xfer_first: the first spi_transfer we want to replace
2173 * @remove: number of transfers to remove
2174 * @insert: the number of transfers we want to insert instead
2175 * @release: extra release code necessary in some circumstances
2176 * @extradatasize: extra data to allocate (with alignment guarantees
2177 * of struct @spi_transfer)
2180 * Returns: pointer to @spi_replaced_transfers,
2181 * PTR_ERR(...) in case of errors.
2183 struct spi_replaced_transfers
*spi_replace_transfers(
2184 struct spi_message
*msg
,
2185 struct spi_transfer
*xfer_first
,
2188 spi_replaced_release_t release
,
2189 size_t extradatasize
,
2192 struct spi_replaced_transfers
*rxfer
;
2193 struct spi_transfer
*xfer
;
2196 /* allocate the structure using spi_res */
2197 rxfer
= spi_res_alloc(msg
->spi
, __spi_replace_transfers_release
,
2198 insert
* sizeof(struct spi_transfer
)
2199 + sizeof(struct spi_replaced_transfers
)
2203 return ERR_PTR(-ENOMEM
);
2205 /* the release code to invoke before running the generic release */
2206 rxfer
->release
= release
;
2208 /* assign extradata */
2211 &rxfer
->inserted_transfers
[insert
];
2213 /* init the replaced_transfers list */
2214 INIT_LIST_HEAD(&rxfer
->replaced_transfers
);
2216 /* assign the list_entry after which we should reinsert
2217 * the @replaced_transfers - it may be spi_message.messages!
2219 rxfer
->replaced_after
= xfer_first
->transfer_list
.prev
;
2221 /* remove the requested number of transfers */
2222 for (i
= 0; i
< remove
; i
++) {
2223 /* if the entry after replaced_after it is msg->transfers
2224 * then we have been requested to remove more transfers
2225 * than are in the list
2227 if (rxfer
->replaced_after
->next
== &msg
->transfers
) {
2228 dev_err(&msg
->spi
->dev
,
2229 "requested to remove more spi_transfers than are available\n");
2230 /* insert replaced transfers back into the message */
2231 list_splice(&rxfer
->replaced_transfers
,
2232 rxfer
->replaced_after
);
2234 /* free the spi_replace_transfer structure */
2235 spi_res_free(rxfer
);
2237 /* and return with an error */
2238 return ERR_PTR(-EINVAL
);
2241 /* remove the entry after replaced_after from list of
2242 * transfers and add it to list of replaced_transfers
2244 list_move_tail(rxfer
->replaced_after
->next
,
2245 &rxfer
->replaced_transfers
);
2248 /* create copy of the given xfer with identical settings
2249 * based on the first transfer to get removed
2251 for (i
= 0; i
< insert
; i
++) {
2252 /* we need to run in reverse order */
2253 xfer
= &rxfer
->inserted_transfers
[insert
- 1 - i
];
2255 /* copy all spi_transfer data */
2256 memcpy(xfer
, xfer_first
, sizeof(*xfer
));
2259 list_add(&xfer
->transfer_list
, rxfer
->replaced_after
);
2261 /* clear cs_change and delay_usecs for all but the last */
2263 xfer
->cs_change
= false;
2264 xfer
->delay_usecs
= 0;
2268 /* set up inserted */
2269 rxfer
->inserted
= insert
;
2271 /* and register it with spi_res/spi_message */
2272 spi_res_add(msg
, rxfer
);
2276 EXPORT_SYMBOL_GPL(spi_replace_transfers
);
2278 static int __spi_split_transfer_maxsize(struct spi_master
*master
,
2279 struct spi_message
*msg
,
2280 struct spi_transfer
**xferp
,
2284 struct spi_transfer
*xfer
= *xferp
, *xfers
;
2285 struct spi_replaced_transfers
*srt
;
2289 /* warn once about this fact that we are splitting a transfer */
2290 dev_warn_once(&msg
->spi
->dev
,
2291 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2292 xfer
->len
, maxsize
);
2294 /* calculate how many we have to replace */
2295 count
= DIV_ROUND_UP(xfer
->len
, maxsize
);
2297 /* create replacement */
2298 srt
= spi_replace_transfers(msg
, xfer
, 1, count
, NULL
, 0, gfp
);
2300 return PTR_ERR(srt
);
2301 xfers
= srt
->inserted_transfers
;
2303 /* now handle each of those newly inserted spi_transfers
2304 * note that the replacements spi_transfers all are preset
2305 * to the same values as *xferp, so tx_buf, rx_buf and len
2306 * are all identical (as well as most others)
2307 * so we just have to fix up len and the pointers.
2309 * this also includes support for the depreciated
2310 * spi_message.is_dma_mapped interface
2313 /* the first transfer just needs the length modified, so we
2314 * run it outside the loop
2316 xfers
[0].len
= min_t(size_t, maxsize
, xfer
[0].len
);
2318 /* all the others need rx_buf/tx_buf also set */
2319 for (i
= 1, offset
= maxsize
; i
< count
; offset
+= maxsize
, i
++) {
2320 /* update rx_buf, tx_buf and dma */
2321 if (xfers
[i
].rx_buf
)
2322 xfers
[i
].rx_buf
+= offset
;
2323 if (xfers
[i
].rx_dma
)
2324 xfers
[i
].rx_dma
+= offset
;
2325 if (xfers
[i
].tx_buf
)
2326 xfers
[i
].tx_buf
+= offset
;
2327 if (xfers
[i
].tx_dma
)
2328 xfers
[i
].tx_dma
+= offset
;
2331 xfers
[i
].len
= min(maxsize
, xfers
[i
].len
- offset
);
2334 /* we set up xferp to the last entry we have inserted,
2335 * so that we skip those already split transfers
2337 *xferp
= &xfers
[count
- 1];
2339 /* increment statistics counters */
2340 SPI_STATISTICS_INCREMENT_FIELD(&master
->statistics
,
2341 transfers_split_maxsize
);
2342 SPI_STATISTICS_INCREMENT_FIELD(&msg
->spi
->statistics
,
2343 transfers_split_maxsize
);
2349 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2350 * when an individual transfer exceeds a
2352 * @master: the @spi_master for this transfer
2353 * @msg: the @spi_message to transform
2354 * @maxsize: the maximum when to apply this
2355 * @gfp: GFP allocation flags
2357 * Return: status of transformation
2359 int spi_split_transfers_maxsize(struct spi_master
*master
,
2360 struct spi_message
*msg
,
2364 struct spi_transfer
*xfer
;
2367 /* iterate over the transfer_list,
2368 * but note that xfer is advanced to the last transfer inserted
2369 * to avoid checking sizes again unnecessarily (also xfer does
2370 * potentiall belong to a different list by the time the
2371 * replacement has happened
2373 list_for_each_entry(xfer
, &msg
->transfers
, transfer_list
) {
2374 if (xfer
->len
> maxsize
) {
2375 ret
= __spi_split_transfer_maxsize(
2376 master
, msg
, &xfer
, maxsize
, gfp
);
2384 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize
);
2386 /*-------------------------------------------------------------------------*/
2388 /* Core methods for SPI master protocol drivers. Some of the
2389 * other core methods are currently defined as inline functions.
2392 static int __spi_validate_bits_per_word(struct spi_master
*master
, u8 bits_per_word
)
2394 if (master
->bits_per_word_mask
) {
2395 /* Only 32 bits fit in the mask */
2396 if (bits_per_word
> 32)
2398 if (!(master
->bits_per_word_mask
&
2399 SPI_BPW_MASK(bits_per_word
)))
2407 * spi_setup - setup SPI mode and clock rate
2408 * @spi: the device whose settings are being modified
2409 * Context: can sleep, and no requests are queued to the device
2411 * SPI protocol drivers may need to update the transfer mode if the
2412 * device doesn't work with its default. They may likewise need
2413 * to update clock rates or word sizes from initial values. This function
2414 * changes those settings, and must be called from a context that can sleep.
2415 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2416 * effect the next time the device is selected and data is transferred to
2417 * or from it. When this function returns, the spi device is deselected.
2419 * Note that this call will fail if the protocol driver specifies an option
2420 * that the underlying controller or its driver does not support. For
2421 * example, not all hardware supports wire transfers using nine bit words,
2422 * LSB-first wire encoding, or active-high chipselects.
2424 * Return: zero on success, else a negative error code.
2426 int spi_setup(struct spi_device
*spi
)
2428 unsigned bad_bits
, ugly_bits
;
2431 /* check mode to prevent that DUAL and QUAD set at the same time
2433 if (((spi
->mode
& SPI_TX_DUAL
) && (spi
->mode
& SPI_TX_QUAD
)) ||
2434 ((spi
->mode
& SPI_RX_DUAL
) && (spi
->mode
& SPI_RX_QUAD
))) {
2436 "setup: can not select dual and quad at the same time\n");
2439 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2441 if ((spi
->mode
& SPI_3WIRE
) && (spi
->mode
&
2442 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_RX_DUAL
| SPI_RX_QUAD
)))
2444 /* help drivers fail *cleanly* when they need options
2445 * that aren't supported with their current master
2447 bad_bits
= spi
->mode
& ~spi
->master
->mode_bits
;
2448 ugly_bits
= bad_bits
&
2449 (SPI_TX_DUAL
| SPI_TX_QUAD
| SPI_RX_DUAL
| SPI_RX_QUAD
);
2452 "setup: ignoring unsupported mode bits %x\n",
2454 spi
->mode
&= ~ugly_bits
;
2455 bad_bits
&= ~ugly_bits
;
2458 dev_err(&spi
->dev
, "setup: unsupported mode bits %x\n",
2463 if (!spi
->bits_per_word
)
2464 spi
->bits_per_word
= 8;
2466 status
= __spi_validate_bits_per_word(spi
->master
, spi
->bits_per_word
);
2470 if (!spi
->max_speed_hz
)
2471 spi
->max_speed_hz
= spi
->master
->max_speed_hz
;
2473 if (spi
->master
->setup
)
2474 status
= spi
->master
->setup(spi
);
2476 spi_set_cs(spi
, false);
2478 dev_dbg(&spi
->dev
, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2479 (int) (spi
->mode
& (SPI_CPOL
| SPI_CPHA
)),
2480 (spi
->mode
& SPI_CS_HIGH
) ? "cs_high, " : "",
2481 (spi
->mode
& SPI_LSB_FIRST
) ? "lsb, " : "",
2482 (spi
->mode
& SPI_3WIRE
) ? "3wire, " : "",
2483 (spi
->mode
& SPI_LOOP
) ? "loopback, " : "",
2484 spi
->bits_per_word
, spi
->max_speed_hz
,
2489 EXPORT_SYMBOL_GPL(spi_setup
);
2491 static int __spi_validate(struct spi_device
*spi
, struct spi_message
*message
)
2493 struct spi_master
*master
= spi
->master
;
2494 struct spi_transfer
*xfer
;
2497 if (list_empty(&message
->transfers
))
2500 /* Half-duplex links include original MicroWire, and ones with
2501 * only one data pin like SPI_3WIRE (switches direction) or where
2502 * either MOSI or MISO is missing. They can also be caused by
2503 * software limitations.
2505 if ((master
->flags
& SPI_MASTER_HALF_DUPLEX
)
2506 || (spi
->mode
& SPI_3WIRE
)) {
2507 unsigned flags
= master
->flags
;
2509 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
2510 if (xfer
->rx_buf
&& xfer
->tx_buf
)
2512 if ((flags
& SPI_MASTER_NO_TX
) && xfer
->tx_buf
)
2514 if ((flags
& SPI_MASTER_NO_RX
) && xfer
->rx_buf
)
2520 * Set transfer bits_per_word and max speed as spi device default if
2521 * it is not set for this transfer.
2522 * Set transfer tx_nbits and rx_nbits as single transfer default
2523 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2525 message
->frame_length
= 0;
2526 list_for_each_entry(xfer
, &message
->transfers
, transfer_list
) {
2527 message
->frame_length
+= xfer
->len
;
2528 if (!xfer
->bits_per_word
)
2529 xfer
->bits_per_word
= spi
->bits_per_word
;
2531 if (!xfer
->speed_hz
)
2532 xfer
->speed_hz
= spi
->max_speed_hz
;
2533 if (!xfer
->speed_hz
)
2534 xfer
->speed_hz
= master
->max_speed_hz
;
2536 if (master
->max_speed_hz
&&
2537 xfer
->speed_hz
> master
->max_speed_hz
)
2538 xfer
->speed_hz
= master
->max_speed_hz
;
2540 if (__spi_validate_bits_per_word(master
, xfer
->bits_per_word
))
2544 * SPI transfer length should be multiple of SPI word size
2545 * where SPI word size should be power-of-two multiple
2547 if (xfer
->bits_per_word
<= 8)
2549 else if (xfer
->bits_per_word
<= 16)
2554 /* No partial transfers accepted */
2555 if (xfer
->len
% w_size
)
2558 if (xfer
->speed_hz
&& master
->min_speed_hz
&&
2559 xfer
->speed_hz
< master
->min_speed_hz
)
2562 if (xfer
->tx_buf
&& !xfer
->tx_nbits
)
2563 xfer
->tx_nbits
= SPI_NBITS_SINGLE
;
2564 if (xfer
->rx_buf
&& !xfer
->rx_nbits
)
2565 xfer
->rx_nbits
= SPI_NBITS_SINGLE
;
2566 /* check transfer tx/rx_nbits:
2567 * 1. check the value matches one of single, dual and quad
2568 * 2. check tx/rx_nbits match the mode in spi_device
2571 if (xfer
->tx_nbits
!= SPI_NBITS_SINGLE
&&
2572 xfer
->tx_nbits
!= SPI_NBITS_DUAL
&&
2573 xfer
->tx_nbits
!= SPI_NBITS_QUAD
)
2575 if ((xfer
->tx_nbits
== SPI_NBITS_DUAL
) &&
2576 !(spi
->mode
& (SPI_TX_DUAL
| SPI_TX_QUAD
)))
2578 if ((xfer
->tx_nbits
== SPI_NBITS_QUAD
) &&
2579 !(spi
->mode
& SPI_TX_QUAD
))
2582 /* check transfer rx_nbits */
2584 if (xfer
->rx_nbits
!= SPI_NBITS_SINGLE
&&
2585 xfer
->rx_nbits
!= SPI_NBITS_DUAL
&&
2586 xfer
->rx_nbits
!= SPI_NBITS_QUAD
)
2588 if ((xfer
->rx_nbits
== SPI_NBITS_DUAL
) &&
2589 !(spi
->mode
& (SPI_RX_DUAL
| SPI_RX_QUAD
)))
2591 if ((xfer
->rx_nbits
== SPI_NBITS_QUAD
) &&
2592 !(spi
->mode
& SPI_RX_QUAD
))
2597 message
->status
= -EINPROGRESS
;
2602 static int __spi_async(struct spi_device
*spi
, struct spi_message
*message
)
2604 struct spi_master
*master
= spi
->master
;
2608 SPI_STATISTICS_INCREMENT_FIELD(&master
->statistics
, spi_async
);
2609 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
, spi_async
);
2611 trace_spi_message_submit(message
);
2613 return master
->transfer(spi
, message
);
2617 * spi_async - asynchronous SPI transfer
2618 * @spi: device with which data will be exchanged
2619 * @message: describes the data transfers, including completion callback
2620 * Context: any (irqs may be blocked, etc)
2622 * This call may be used in_irq and other contexts which can't sleep,
2623 * as well as from task contexts which can sleep.
2625 * The completion callback is invoked in a context which can't sleep.
2626 * Before that invocation, the value of message->status is undefined.
2627 * When the callback is issued, message->status holds either zero (to
2628 * indicate complete success) or a negative error code. After that
2629 * callback returns, the driver which issued the transfer request may
2630 * deallocate the associated memory; it's no longer in use by any SPI
2631 * core or controller driver code.
2633 * Note that although all messages to a spi_device are handled in
2634 * FIFO order, messages may go to different devices in other orders.
2635 * Some device might be higher priority, or have various "hard" access
2636 * time requirements, for example.
2638 * On detection of any fault during the transfer, processing of
2639 * the entire message is aborted, and the device is deselected.
2640 * Until returning from the associated message completion callback,
2641 * no other spi_message queued to that device will be processed.
2642 * (This rule applies equally to all the synchronous transfer calls,
2643 * which are wrappers around this core asynchronous primitive.)
2645 * Return: zero on success, else a negative error code.
2647 int spi_async(struct spi_device
*spi
, struct spi_message
*message
)
2649 struct spi_master
*master
= spi
->master
;
2651 unsigned long flags
;
2653 ret
= __spi_validate(spi
, message
);
2657 spin_lock_irqsave(&master
->bus_lock_spinlock
, flags
);
2659 if (master
->bus_lock_flag
)
2662 ret
= __spi_async(spi
, message
);
2664 spin_unlock_irqrestore(&master
->bus_lock_spinlock
, flags
);
2668 EXPORT_SYMBOL_GPL(spi_async
);
2671 * spi_async_locked - version of spi_async with exclusive bus usage
2672 * @spi: device with which data will be exchanged
2673 * @message: describes the data transfers, including completion callback
2674 * Context: any (irqs may be blocked, etc)
2676 * This call may be used in_irq and other contexts which can't sleep,
2677 * as well as from task contexts which can sleep.
2679 * The completion callback is invoked in a context which can't sleep.
2680 * Before that invocation, the value of message->status is undefined.
2681 * When the callback is issued, message->status holds either zero (to
2682 * indicate complete success) or a negative error code. After that
2683 * callback returns, the driver which issued the transfer request may
2684 * deallocate the associated memory; it's no longer in use by any SPI
2685 * core or controller driver code.
2687 * Note that although all messages to a spi_device are handled in
2688 * FIFO order, messages may go to different devices in other orders.
2689 * Some device might be higher priority, or have various "hard" access
2690 * time requirements, for example.
2692 * On detection of any fault during the transfer, processing of
2693 * the entire message is aborted, and the device is deselected.
2694 * Until returning from the associated message completion callback,
2695 * no other spi_message queued to that device will be processed.
2696 * (This rule applies equally to all the synchronous transfer calls,
2697 * which are wrappers around this core asynchronous primitive.)
2699 * Return: zero on success, else a negative error code.
2701 int spi_async_locked(struct spi_device
*spi
, struct spi_message
*message
)
2703 struct spi_master
*master
= spi
->master
;
2705 unsigned long flags
;
2707 ret
= __spi_validate(spi
, message
);
2711 spin_lock_irqsave(&master
->bus_lock_spinlock
, flags
);
2713 ret
= __spi_async(spi
, message
);
2715 spin_unlock_irqrestore(&master
->bus_lock_spinlock
, flags
);
2720 EXPORT_SYMBOL_GPL(spi_async_locked
);
2723 int spi_flash_read(struct spi_device
*spi
,
2724 struct spi_flash_read_message
*msg
)
2727 struct spi_master
*master
= spi
->master
;
2730 if ((msg
->opcode_nbits
== SPI_NBITS_DUAL
||
2731 msg
->addr_nbits
== SPI_NBITS_DUAL
) &&
2732 !(spi
->mode
& (SPI_TX_DUAL
| SPI_TX_QUAD
)))
2734 if ((msg
->opcode_nbits
== SPI_NBITS_QUAD
||
2735 msg
->addr_nbits
== SPI_NBITS_QUAD
) &&
2736 !(spi
->mode
& SPI_TX_QUAD
))
2738 if (msg
->data_nbits
== SPI_NBITS_DUAL
&&
2739 !(spi
->mode
& (SPI_RX_DUAL
| SPI_RX_QUAD
)))
2741 if (msg
->data_nbits
== SPI_NBITS_QUAD
&&
2742 !(spi
->mode
& SPI_RX_QUAD
))
2745 if (master
->auto_runtime_pm
) {
2746 ret
= pm_runtime_get_sync(master
->dev
.parent
);
2748 dev_err(&master
->dev
, "Failed to power device: %d\n",
2753 mutex_lock(&master
->bus_lock_mutex
);
2754 ret
= master
->spi_flash_read(spi
, msg
);
2755 mutex_unlock(&master
->bus_lock_mutex
);
2756 if (master
->auto_runtime_pm
)
2757 pm_runtime_put(master
->dev
.parent
);
2761 EXPORT_SYMBOL_GPL(spi_flash_read
);
2763 /*-------------------------------------------------------------------------*/
2765 /* Utility methods for SPI master protocol drivers, layered on
2766 * top of the core. Some other utility methods are defined as
2770 static void spi_complete(void *arg
)
2775 static int __spi_sync(struct spi_device
*spi
, struct spi_message
*message
,
2778 DECLARE_COMPLETION_ONSTACK(done
);
2780 struct spi_master
*master
= spi
->master
;
2781 unsigned long flags
;
2783 status
= __spi_validate(spi
, message
);
2787 message
->complete
= spi_complete
;
2788 message
->context
= &done
;
2791 SPI_STATISTICS_INCREMENT_FIELD(&master
->statistics
, spi_sync
);
2792 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
, spi_sync
);
2795 mutex_lock(&master
->bus_lock_mutex
);
2797 /* If we're not using the legacy transfer method then we will
2798 * try to transfer in the calling context so special case.
2799 * This code would be less tricky if we could remove the
2800 * support for driver implemented message queues.
2802 if (master
->transfer
== spi_queued_transfer
) {
2803 spin_lock_irqsave(&master
->bus_lock_spinlock
, flags
);
2805 trace_spi_message_submit(message
);
2807 status
= __spi_queued_transfer(spi
, message
, false);
2809 spin_unlock_irqrestore(&master
->bus_lock_spinlock
, flags
);
2811 status
= spi_async_locked(spi
, message
);
2815 mutex_unlock(&master
->bus_lock_mutex
);
2818 /* Push out the messages in the calling context if we
2821 if (master
->transfer
== spi_queued_transfer
) {
2822 SPI_STATISTICS_INCREMENT_FIELD(&master
->statistics
,
2823 spi_sync_immediate
);
2824 SPI_STATISTICS_INCREMENT_FIELD(&spi
->statistics
,
2825 spi_sync_immediate
);
2826 __spi_pump_messages(master
, false, bus_locked
);
2829 wait_for_completion(&done
);
2830 status
= message
->status
;
2832 message
->context
= NULL
;
2837 * spi_sync - blocking/synchronous SPI data transfers
2838 * @spi: device with which data will be exchanged
2839 * @message: describes the data transfers
2840 * Context: can sleep
2842 * This call may only be used from a context that may sleep. The sleep
2843 * is non-interruptible, and has no timeout. Low-overhead controller
2844 * drivers may DMA directly into and out of the message buffers.
2846 * Note that the SPI device's chip select is active during the message,
2847 * and then is normally disabled between messages. Drivers for some
2848 * frequently-used devices may want to minimize costs of selecting a chip,
2849 * by leaving it selected in anticipation that the next message will go
2850 * to the same chip. (That may increase power usage.)
2852 * Also, the caller is guaranteeing that the memory associated with the
2853 * message will not be freed before this call returns.
2855 * Return: zero on success, else a negative error code.
2857 int spi_sync(struct spi_device
*spi
, struct spi_message
*message
)
2859 return __spi_sync(spi
, message
, spi
->master
->bus_lock_flag
);
2861 EXPORT_SYMBOL_GPL(spi_sync
);
2864 * spi_sync_locked - version of spi_sync with exclusive bus usage
2865 * @spi: device with which data will be exchanged
2866 * @message: describes the data transfers
2867 * Context: can sleep
2869 * This call may only be used from a context that may sleep. The sleep
2870 * is non-interruptible, and has no timeout. Low-overhead controller
2871 * drivers may DMA directly into and out of the message buffers.
2873 * This call should be used by drivers that require exclusive access to the
2874 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
2875 * be released by a spi_bus_unlock call when the exclusive access is over.
2877 * Return: zero on success, else a negative error code.
2879 int spi_sync_locked(struct spi_device
*spi
, struct spi_message
*message
)
2881 return __spi_sync(spi
, message
, 1);
2883 EXPORT_SYMBOL_GPL(spi_sync_locked
);
2886 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2887 * @master: SPI bus master that should be locked for exclusive bus access
2888 * Context: can sleep
2890 * This call may only be used from a context that may sleep. The sleep
2891 * is non-interruptible, and has no timeout.
2893 * This call should be used by drivers that require exclusive access to the
2894 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2895 * exclusive access is over. Data transfer must be done by spi_sync_locked
2896 * and spi_async_locked calls when the SPI bus lock is held.
2898 * Return: always zero.
2900 int spi_bus_lock(struct spi_master
*master
)
2902 unsigned long flags
;
2904 mutex_lock(&master
->bus_lock_mutex
);
2906 spin_lock_irqsave(&master
->bus_lock_spinlock
, flags
);
2907 master
->bus_lock_flag
= 1;
2908 spin_unlock_irqrestore(&master
->bus_lock_spinlock
, flags
);
2910 /* mutex remains locked until spi_bus_unlock is called */
2914 EXPORT_SYMBOL_GPL(spi_bus_lock
);
2917 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2918 * @master: SPI bus master that was locked for exclusive bus access
2919 * Context: can sleep
2921 * This call may only be used from a context that may sleep. The sleep
2922 * is non-interruptible, and has no timeout.
2924 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2927 * Return: always zero.
2929 int spi_bus_unlock(struct spi_master
*master
)
2931 master
->bus_lock_flag
= 0;
2933 mutex_unlock(&master
->bus_lock_mutex
);
2937 EXPORT_SYMBOL_GPL(spi_bus_unlock
);
2939 /* portable code must never pass more than 32 bytes */
2940 #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
2945 * spi_write_then_read - SPI synchronous write followed by read
2946 * @spi: device with which data will be exchanged
2947 * @txbuf: data to be written (need not be dma-safe)
2948 * @n_tx: size of txbuf, in bytes
2949 * @rxbuf: buffer into which data will be read (need not be dma-safe)
2950 * @n_rx: size of rxbuf, in bytes
2951 * Context: can sleep
2953 * This performs a half duplex MicroWire style transaction with the
2954 * device, sending txbuf and then reading rxbuf. The return value
2955 * is zero for success, else a negative errno status code.
2956 * This call may only be used from a context that may sleep.
2958 * Parameters to this routine are always copied using a small buffer;
2959 * portable code should never use this for more than 32 bytes.
2960 * Performance-sensitive or bulk transfer code should instead use
2961 * spi_{async,sync}() calls with dma-safe buffers.
2963 * Return: zero on success, else a negative error code.
2965 int spi_write_then_read(struct spi_device
*spi
,
2966 const void *txbuf
, unsigned n_tx
,
2967 void *rxbuf
, unsigned n_rx
)
2969 static DEFINE_MUTEX(lock
);
2972 struct spi_message message
;
2973 struct spi_transfer x
[2];
2976 /* Use preallocated DMA-safe buffer if we can. We can't avoid
2977 * copying here, (as a pure convenience thing), but we can
2978 * keep heap costs out of the hot path unless someone else is
2979 * using the pre-allocated buffer or the transfer is too large.
2981 if ((n_tx
+ n_rx
) > SPI_BUFSIZ
|| !mutex_trylock(&lock
)) {
2982 local_buf
= kmalloc(max((unsigned)SPI_BUFSIZ
, n_tx
+ n_rx
),
2983 GFP_KERNEL
| GFP_DMA
);
2990 spi_message_init(&message
);
2991 memset(x
, 0, sizeof(x
));
2994 spi_message_add_tail(&x
[0], &message
);
2998 spi_message_add_tail(&x
[1], &message
);
3001 memcpy(local_buf
, txbuf
, n_tx
);
3002 x
[0].tx_buf
= local_buf
;
3003 x
[1].rx_buf
= local_buf
+ n_tx
;
3006 status
= spi_sync(spi
, &message
);
3008 memcpy(rxbuf
, x
[1].rx_buf
, n_rx
);
3010 if (x
[0].tx_buf
== buf
)
3011 mutex_unlock(&lock
);
3017 EXPORT_SYMBOL_GPL(spi_write_then_read
);
3019 /*-------------------------------------------------------------------------*/
3021 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
3022 static int __spi_of_device_match(struct device
*dev
, void *data
)
3024 return dev
->of_node
== data
;
3027 /* must call put_device() when done with returned spi_device device */
3028 static struct spi_device
*of_find_spi_device_by_node(struct device_node
*node
)
3030 struct device
*dev
= bus_find_device(&spi_bus_type
, NULL
, node
,
3031 __spi_of_device_match
);
3032 return dev
? to_spi_device(dev
) : NULL
;
3035 static int __spi_of_master_match(struct device
*dev
, const void *data
)
3037 return dev
->of_node
== data
;
3040 /* the spi masters are not using spi_bus, so we find it with another way */
3041 static struct spi_master
*of_find_spi_master_by_node(struct device_node
*node
)
3045 dev
= class_find_device(&spi_master_class
, NULL
, node
,
3046 __spi_of_master_match
);
3050 /* reference got in class_find_device */
3051 return container_of(dev
, struct spi_master
, dev
);
3054 static int of_spi_notify(struct notifier_block
*nb
, unsigned long action
,
3057 struct of_reconfig_data
*rd
= arg
;
3058 struct spi_master
*master
;
3059 struct spi_device
*spi
;
3061 switch (of_reconfig_get_state_change(action
, arg
)) {
3062 case OF_RECONFIG_CHANGE_ADD
:
3063 master
= of_find_spi_master_by_node(rd
->dn
->parent
);
3065 return NOTIFY_OK
; /* not for us */
3067 if (of_node_test_and_set_flag(rd
->dn
, OF_POPULATED
)) {
3068 put_device(&master
->dev
);
3072 spi
= of_register_spi_device(master
, rd
->dn
);
3073 put_device(&master
->dev
);
3076 pr_err("%s: failed to create for '%s'\n",
3077 __func__
, rd
->dn
->full_name
);
3078 return notifier_from_errno(PTR_ERR(spi
));
3082 case OF_RECONFIG_CHANGE_REMOVE
:
3083 /* already depopulated? */
3084 if (!of_node_check_flag(rd
->dn
, OF_POPULATED
))
3087 /* find our device by node */
3088 spi
= of_find_spi_device_by_node(rd
->dn
);
3090 return NOTIFY_OK
; /* no? not meant for us */
3092 /* unregister takes one ref away */
3093 spi_unregister_device(spi
);
3095 /* and put the reference of the find */
3096 put_device(&spi
->dev
);
3103 static struct notifier_block spi_of_notifier
= {
3104 .notifier_call
= of_spi_notify
,
3106 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3107 extern struct notifier_block spi_of_notifier
;
3108 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3110 static int __init
spi_init(void)
3114 buf
= kmalloc(SPI_BUFSIZ
, GFP_KERNEL
);
3120 status
= bus_register(&spi_bus_type
);
3124 status
= class_register(&spi_master_class
);
3128 if (IS_ENABLED(CONFIG_OF_DYNAMIC
))
3129 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier
));
3134 bus_unregister(&spi_bus_type
);
3142 /* board_info is normally registered in arch_initcall(),
3143 * but even essential drivers wait till later
3145 * REVISIT only boardinfo really needs static linking. the rest (device and
3146 * driver registration) _could_ be dynamically linked (modular) ... costs
3147 * include needing to have boardinfo data structures be much more public.
3149 postcore_initcall(spi_init
);