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1/*
2 * SPI init/core code
3 *
4 * Copyright (C) 2005 David Brownell
5 * Copyright (C) 2008 Secret Lab Technologies Ltd.
6 *
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.
11 *
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.
16 */
17
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
41#define CREATE_TRACE_POINTS
42#include <trace/events/spi.h>
43
44static void spidev_release(struct device *dev)
45{
46 struct spi_device *spi = to_spi_device(dev);
47
48 /* spi masters may cleanup for released devices */
49 if (spi->master->cleanup)
50 spi->master->cleanup(spi);
51
52 spi_master_put(spi->master);
53 kfree(spi);
54}
55
56static ssize_t
57modalias_show(struct device *dev, struct device_attribute *a, char *buf)
58{
59 const struct spi_device *spi = to_spi_device(dev);
60 int len;
61
62 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
63 if (len != -ENODEV)
64 return len;
65
66 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
67}
68static DEVICE_ATTR_RO(modalias);
69
70#define SPI_STATISTICS_ATTRS(field, file) \
71static ssize_t spi_master_##field##_show(struct device *dev, \
72 struct device_attribute *attr, \
73 char *buf) \
74{ \
75 struct spi_master *master = container_of(dev, \
76 struct spi_master, dev); \
77 return spi_statistics_##field##_show(&master->statistics, buf); \
78} \
79static struct device_attribute dev_attr_spi_master_##field = { \
80 .attr = { .name = file, .mode = S_IRUGO }, \
81 .show = spi_master_##field##_show, \
82}; \
83static ssize_t spi_device_##field##_show(struct device *dev, \
84 struct device_attribute *attr, \
85 char *buf) \
86{ \
87 struct spi_device *spi = to_spi_device(dev); \
88 return spi_statistics_##field##_show(&spi->statistics, buf); \
89} \
90static struct device_attribute dev_attr_spi_device_##field = { \
91 .attr = { .name = file, .mode = S_IRUGO }, \
92 .show = spi_device_##field##_show, \
93}
94
95#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
96static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
97 char *buf) \
98{ \
99 unsigned long flags; \
100 ssize_t len; \
101 spin_lock_irqsave(&stat->lock, flags); \
102 len = sprintf(buf, format_string, stat->field); \
103 spin_unlock_irqrestore(&stat->lock, flags); \
104 return len; \
105} \
106SPI_STATISTICS_ATTRS(name, file)
107
108#define SPI_STATISTICS_SHOW(field, format_string) \
109 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
110 field, format_string)
111
112SPI_STATISTICS_SHOW(messages, "%lu");
113SPI_STATISTICS_SHOW(transfers, "%lu");
114SPI_STATISTICS_SHOW(errors, "%lu");
115SPI_STATISTICS_SHOW(timedout, "%lu");
116
117SPI_STATISTICS_SHOW(spi_sync, "%lu");
118SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
119SPI_STATISTICS_SHOW(spi_async, "%lu");
120
121SPI_STATISTICS_SHOW(bytes, "%llu");
122SPI_STATISTICS_SHOW(bytes_rx, "%llu");
123SPI_STATISTICS_SHOW(bytes_tx, "%llu");
124
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")
129SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
130SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
131SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
132SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
133SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
134SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
135SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
136SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
137SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
138SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
139SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
140SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
141SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
142SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
143SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
144SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
145SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
146
147SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
148
149static struct attribute *spi_dev_attrs[] = {
150 &dev_attr_modalias.attr,
151 NULL,
152};
153
154static const struct attribute_group spi_dev_group = {
155 .attrs = spi_dev_attrs,
156};
157
158static 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,
187 NULL,
188};
189
190static const struct attribute_group spi_device_statistics_group = {
191 .name = "statistics",
192 .attrs = spi_device_statistics_attrs,
193};
194
195static const struct attribute_group *spi_dev_groups[] = {
196 &spi_dev_group,
197 &spi_device_statistics_group,
198 NULL,
199};
200
201static 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,
230 NULL,
231};
232
233static const struct attribute_group spi_master_statistics_group = {
234 .name = "statistics",
235 .attrs = spi_master_statistics_attrs,
236};
237
238static const struct attribute_group *spi_master_groups[] = {
239 &spi_master_statistics_group,
240 NULL,
241};
242
243void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
244 struct spi_transfer *xfer,
245 struct spi_master *master)
246{
247 unsigned long flags;
248 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
249
250 if (l2len < 0)
251 l2len = 0;
252
253 spin_lock_irqsave(&stats->lock, flags);
254
255 stats->transfers++;
256 stats->transfer_bytes_histo[l2len]++;
257
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;
265
266 spin_unlock_irqrestore(&stats->lock, flags);
267}
268EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
269
270/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
271 * and the sysfs version makes coldplug work too.
272 */
273
274static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
275 const struct spi_device *sdev)
276{
277 while (id->name[0]) {
278 if (!strcmp(sdev->modalias, id->name))
279 return id;
280 id++;
281 }
282 return NULL;
283}
284
285const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
286{
287 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
288
289 return spi_match_id(sdrv->id_table, sdev);
290}
291EXPORT_SYMBOL_GPL(spi_get_device_id);
292
293static int spi_match_device(struct device *dev, struct device_driver *drv)
294{
295 const struct spi_device *spi = to_spi_device(dev);
296 const struct spi_driver *sdrv = to_spi_driver(drv);
297
298 /* Attempt an OF style match */
299 if (of_driver_match_device(dev, drv))
300 return 1;
301
302 /* Then try ACPI */
303 if (acpi_driver_match_device(dev, drv))
304 return 1;
305
306 if (sdrv->id_table)
307 return !!spi_match_id(sdrv->id_table, spi);
308
309 return strcmp(spi->modalias, drv->name) == 0;
310}
311
312static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
313{
314 const struct spi_device *spi = to_spi_device(dev);
315 int rc;
316
317 rc = acpi_device_uevent_modalias(dev, env);
318 if (rc != -ENODEV)
319 return rc;
320
321 add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
322 return 0;
323}
324
325struct bus_type spi_bus_type = {
326 .name = "spi",
327 .dev_groups = spi_dev_groups,
328 .match = spi_match_device,
329 .uevent = spi_uevent,
330};
331EXPORT_SYMBOL_GPL(spi_bus_type);
332
333
334static int spi_drv_probe(struct device *dev)
335{
336 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
337 struct spi_device *spi = to_spi_device(dev);
338 int ret;
339
340 ret = of_clk_set_defaults(dev->of_node, false);
341 if (ret)
342 return ret;
343
344 if (dev->of_node) {
345 spi->irq = of_irq_get(dev->of_node, 0);
346 if (spi->irq == -EPROBE_DEFER)
347 return -EPROBE_DEFER;
348 if (spi->irq < 0)
349 spi->irq = 0;
350 }
351
352 ret = dev_pm_domain_attach(dev, true);
353 if (ret != -EPROBE_DEFER) {
354 ret = sdrv->probe(spi);
355 if (ret)
356 dev_pm_domain_detach(dev, true);
357 }
358
359 return ret;
360}
361
362static int spi_drv_remove(struct device *dev)
363{
364 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
365 int ret;
366
367 ret = sdrv->remove(to_spi_device(dev));
368 dev_pm_domain_detach(dev, true);
369
370 return ret;
371}
372
373static void spi_drv_shutdown(struct device *dev)
374{
375 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
376
377 sdrv->shutdown(to_spi_device(dev));
378}
379
380/**
381 * __spi_register_driver - register a SPI driver
382 * @owner: owner module of the driver to register
383 * @sdrv: the driver to register
384 * Context: can sleep
385 *
386 * Return: zero on success, else a negative error code.
387 */
388int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
389{
390 sdrv->driver.owner = owner;
391 sdrv->driver.bus = &spi_bus_type;
392 if (sdrv->probe)
393 sdrv->driver.probe = spi_drv_probe;
394 if (sdrv->remove)
395 sdrv->driver.remove = spi_drv_remove;
396 if (sdrv->shutdown)
397 sdrv->driver.shutdown = spi_drv_shutdown;
398 return driver_register(&sdrv->driver);
399}
400EXPORT_SYMBOL_GPL(__spi_register_driver);
401
402/*-------------------------------------------------------------------------*/
403
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.
408 */
409
410struct boardinfo {
411 struct list_head list;
412 struct spi_board_info board_info;
413};
414
415static LIST_HEAD(board_list);
416static LIST_HEAD(spi_master_list);
417
418/*
419 * Used to protect add/del opertion for board_info list and
420 * spi_master list, and their matching process
421 */
422static DEFINE_MUTEX(board_lock);
423
424/**
425 * spi_alloc_device - Allocate a new SPI device
426 * @master: Controller to which device is connected
427 * Context: can sleep
428 *
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.
433 *
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.
438 *
439 * Return: a pointer to the new device, or NULL.
440 */
441struct spi_device *spi_alloc_device(struct spi_master *master)
442{
443 struct spi_device *spi;
444
445 if (!spi_master_get(master))
446 return NULL;
447
448 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
449 if (!spi) {
450 spi_master_put(master);
451 return NULL;
452 }
453
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;
459
460 spin_lock_init(&spi->statistics.lock);
461
462 device_initialize(&spi->dev);
463 return spi;
464}
465EXPORT_SYMBOL_GPL(spi_alloc_device);
466
467static void spi_dev_set_name(struct spi_device *spi)
468{
469 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
470
471 if (adev) {
472 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
473 return;
474 }
475
476 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
477 spi->chip_select);
478}
479
480static int spi_dev_check(struct device *dev, void *data)
481{
482 struct spi_device *spi = to_spi_device(dev);
483 struct spi_device *new_spi = data;
484
485 if (spi->master == new_spi->master &&
486 spi->chip_select == new_spi->chip_select)
487 return -EBUSY;
488 return 0;
489}
490
491/**
492 * spi_add_device - Add spi_device allocated with spi_alloc_device
493 * @spi: spi_device to register
494 *
495 * Companion function to spi_alloc_device. Devices allocated with
496 * spi_alloc_device can be added onto the spi bus with this function.
497 *
498 * Return: 0 on success; negative errno on failure
499 */
500int spi_add_device(struct spi_device *spi)
501{
502 static DEFINE_MUTEX(spi_add_lock);
503 struct spi_master *master = spi->master;
504 struct device *dev = master->dev.parent;
505 int status;
506
507 /* Chipselects are numbered 0..max; validate. */
508 if (spi->chip_select >= master->num_chipselect) {
509 dev_err(dev, "cs%d >= max %d\n",
510 spi->chip_select,
511 master->num_chipselect);
512 return -EINVAL;
513 }
514
515 /* Set the bus ID string */
516 spi_dev_set_name(spi);
517
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.
521 */
522 mutex_lock(&spi_add_lock);
523
524 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
525 if (status) {
526 dev_err(dev, "chipselect %d already in use\n",
527 spi->chip_select);
528 goto done;
529 }
530
531 if (master->cs_gpios)
532 spi->cs_gpio = master->cs_gpios[spi->chip_select];
533
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...
537 */
538 status = spi_setup(spi);
539 if (status < 0) {
540 dev_err(dev, "can't setup %s, status %d\n",
541 dev_name(&spi->dev), status);
542 goto done;
543 }
544
545 /* Device may be bound to an active driver when this returns */
546 status = device_add(&spi->dev);
547 if (status < 0)
548 dev_err(dev, "can't add %s, status %d\n",
549 dev_name(&spi->dev), status);
550 else
551 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
552
553done:
554 mutex_unlock(&spi_add_lock);
555 return status;
556}
557EXPORT_SYMBOL_GPL(spi_add_device);
558
559/**
560 * spi_new_device - instantiate one new SPI device
561 * @master: Controller to which device is connected
562 * @chip: Describes the SPI device
563 * Context: can sleep
564 *
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).
570 *
571 * Return: the new device, or NULL.
572 */
573struct spi_device *spi_new_device(struct spi_master *master,
574 struct spi_board_info *chip)
575{
576 struct spi_device *proxy;
577 int status;
578
579 /* NOTE: caller did any chip->bus_num checks necessary.
580 *
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).
584 */
585
586 proxy = spi_alloc_device(master);
587 if (!proxy)
588 return NULL;
589
590 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
591
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;
600
601 status = spi_add_device(proxy);
602 if (status < 0) {
603 spi_dev_put(proxy);
604 return NULL;
605 }
606
607 return proxy;
608}
609EXPORT_SYMBOL_GPL(spi_new_device);
610
611/**
612 * spi_unregister_device - unregister a single SPI device
613 * @spi: spi_device to unregister
614 *
615 * Start making the passed SPI device vanish. Normally this would be handled
616 * by spi_unregister_master().
617 */
618void spi_unregister_device(struct spi_device *spi)
619{
620 if (!spi)
621 return;
622
623 if (spi->dev.of_node)
624 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
625 device_unregister(&spi->dev);
626}
627EXPORT_SYMBOL_GPL(spi_unregister_device);
628
629static void spi_match_master_to_boardinfo(struct spi_master *master,
630 struct spi_board_info *bi)
631{
632 struct spi_device *dev;
633
634 if (master->bus_num != bi->bus_num)
635 return;
636
637 dev = spi_new_device(master, bi);
638 if (!dev)
639 dev_err(master->dev.parent, "can't create new device for %s\n",
640 bi->modalias);
641}
642
643/**
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
647 * Context: can sleep
648 *
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.
654 *
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.
658 *
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.
661 *
662 * Return: zero on success, else a negative error code.
663 */
664int spi_register_board_info(struct spi_board_info const *info, unsigned n)
665{
666 struct boardinfo *bi;
667 int i;
668
669 if (!n)
670 return -EINVAL;
671
672 bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
673 if (!bi)
674 return -ENOMEM;
675
676 for (i = 0; i < n; i++, bi++, info++) {
677 struct spi_master *master;
678
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);
685 }
686
687 return 0;
688}
689
690/*-------------------------------------------------------------------------*/
691
692static void spi_set_cs(struct spi_device *spi, bool enable)
693{
694 if (spi->mode & SPI_CS_HIGH)
695 enable = !enable;
696
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);
701}
702
703#ifdef CONFIG_HAS_DMA
704static 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)
707{
708 const bool vmalloced_buf = is_vmalloc_addr(buf);
709 unsigned int max_seg_size = dma_get_max_seg_size(dev);
710 int desc_len;
711 int sgs;
712 struct page *vm_page;
713 void *sg_buf;
714 size_t min;
715 int i, ret;
716
717 if (vmalloced_buf) {
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 {
721 desc_len = min_t(int, max_seg_size, master->max_dma_len);
722 sgs = DIV_ROUND_UP(len, desc_len);
723 }
724
725 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
726 if (ret != 0)
727 return ret;
728
729 for (i = 0; i < sgs; i++) {
730
731 if (vmalloced_buf) {
732 min = min_t(size_t,
733 len, desc_len - offset_in_page(buf));
734 vm_page = vmalloc_to_page(buf);
735 if (!vm_page) {
736 sg_free_table(sgt);
737 return -ENOMEM;
738 }
739 sg_set_page(&sgt->sgl[i], vm_page,
740 min, offset_in_page(buf));
741 } else {
742 min = min_t(size_t, len, desc_len);
743 sg_buf = buf;
744 sg_set_buf(&sgt->sgl[i], sg_buf, min);
745 }
746
747 buf += min;
748 len -= min;
749 }
750
751 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
752 if (!ret)
753 ret = -ENOMEM;
754 if (ret < 0) {
755 sg_free_table(sgt);
756 return ret;
757 }
758
759 sgt->nents = ret;
760
761 return 0;
762}
763
764static void spi_unmap_buf(struct spi_master *master, struct device *dev,
765 struct sg_table *sgt, enum dma_data_direction dir)
766{
767 if (sgt->orig_nents) {
768 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
769 sg_free_table(sgt);
770 }
771}
772
773static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
774{
775 struct device *tx_dev, *rx_dev;
776 struct spi_transfer *xfer;
777 int ret;
778
779 if (!master->can_dma)
780 return 0;
781
782 if (master->dma_tx)
783 tx_dev = master->dma_tx->device->dev;
784 else
785 tx_dev = &master->dev;
786
787 if (master->dma_rx)
788 rx_dev = master->dma_rx->device->dev;
789 else
790 rx_dev = &master->dev;
791
792 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
793 if (!master->can_dma(master, msg->spi, xfer))
794 continue;
795
796 if (xfer->tx_buf != NULL) {
797 ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
798 (void *)xfer->tx_buf, xfer->len,
799 DMA_TO_DEVICE);
800 if (ret != 0)
801 return ret;
802 }
803
804 if (xfer->rx_buf != NULL) {
805 ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
806 xfer->rx_buf, xfer->len,
807 DMA_FROM_DEVICE);
808 if (ret != 0) {
809 spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
810 DMA_TO_DEVICE);
811 return ret;
812 }
813 }
814 }
815
816 master->cur_msg_mapped = true;
817
818 return 0;
819}
820
821static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
822{
823 struct spi_transfer *xfer;
824 struct device *tx_dev, *rx_dev;
825
826 if (!master->cur_msg_mapped || !master->can_dma)
827 return 0;
828
829 if (master->dma_tx)
830 tx_dev = master->dma_tx->device->dev;
831 else
832 tx_dev = &master->dev;
833
834 if (master->dma_rx)
835 rx_dev = master->dma_rx->device->dev;
836 else
837 rx_dev = &master->dev;
838
839 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
840 if (!master->can_dma(master, msg->spi, xfer))
841 continue;
842
843 spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
844 spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
845 }
846
847 return 0;
848}
849#else /* !CONFIG_HAS_DMA */
850static inline int __spi_map_msg(struct spi_master *master,
851 struct spi_message *msg)
852{
853 return 0;
854}
855
856static inline int __spi_unmap_msg(struct spi_master *master,
857 struct spi_message *msg)
858{
859 return 0;
860}
861#endif /* !CONFIG_HAS_DMA */
862
863static inline int spi_unmap_msg(struct spi_master *master,
864 struct spi_message *msg)
865{
866 struct spi_transfer *xfer;
867
868 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
869 /*
870 * Restore the original value of tx_buf or rx_buf if they are
871 * NULL.
872 */
873 if (xfer->tx_buf == master->dummy_tx)
874 xfer->tx_buf = NULL;
875 if (xfer->rx_buf == master->dummy_rx)
876 xfer->rx_buf = NULL;
877 }
878
879 return __spi_unmap_msg(master, msg);
880}
881
882static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
883{
884 struct spi_transfer *xfer;
885 void *tmp;
886 unsigned int max_tx, max_rx;
887
888 if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
889 max_tx = 0;
890 max_rx = 0;
891
892 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
893 if ((master->flags & SPI_MASTER_MUST_TX) &&
894 !xfer->tx_buf)
895 max_tx = max(xfer->len, max_tx);
896 if ((master->flags & SPI_MASTER_MUST_RX) &&
897 !xfer->rx_buf)
898 max_rx = max(xfer->len, max_rx);
899 }
900
901 if (max_tx) {
902 tmp = krealloc(master->dummy_tx, max_tx,
903 GFP_KERNEL | GFP_DMA);
904 if (!tmp)
905 return -ENOMEM;
906 master->dummy_tx = tmp;
907 memset(tmp, 0, max_tx);
908 }
909
910 if (max_rx) {
911 tmp = krealloc(master->dummy_rx, max_rx,
912 GFP_KERNEL | GFP_DMA);
913 if (!tmp)
914 return -ENOMEM;
915 master->dummy_rx = tmp;
916 }
917
918 if (max_tx || max_rx) {
919 list_for_each_entry(xfer, &msg->transfers,
920 transfer_list) {
921 if (!xfer->tx_buf)
922 xfer->tx_buf = master->dummy_tx;
923 if (!xfer->rx_buf)
924 xfer->rx_buf = master->dummy_rx;
925 }
926 }
927 }
928
929 return __spi_map_msg(master, msg);
930}
931
932/*
933 * spi_transfer_one_message - Default implementation of transfer_one_message()
934 *
935 * This is a standard implementation of transfer_one_message() for
936 * drivers which impelment a transfer_one() operation. It provides
937 * standard handling of delays and chip select management.
938 */
939static int spi_transfer_one_message(struct spi_master *master,
940 struct spi_message *msg)
941{
942 struct spi_transfer *xfer;
943 bool keep_cs = false;
944 int ret = 0;
945 unsigned long ms = 1;
946 struct spi_statistics *statm = &master->statistics;
947 struct spi_statistics *stats = &msg->spi->statistics;
948
949 spi_set_cs(msg->spi, true);
950
951 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
952 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
953
954 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
955 trace_spi_transfer_start(msg, xfer);
956
957 spi_statistics_add_transfer_stats(statm, xfer, master);
958 spi_statistics_add_transfer_stats(stats, xfer, master);
959
960 if (xfer->tx_buf || xfer->rx_buf) {
961 reinit_completion(&master->xfer_completion);
962
963 ret = master->transfer_one(master, msg->spi, xfer);
964 if (ret < 0) {
965 SPI_STATISTICS_INCREMENT_FIELD(statm,
966 errors);
967 SPI_STATISTICS_INCREMENT_FIELD(stats,
968 errors);
969 dev_err(&msg->spi->dev,
970 "SPI transfer failed: %d\n", ret);
971 goto out;
972 }
973
974 if (ret > 0) {
975 ret = 0;
976 ms = xfer->len * 8 * 1000 / xfer->speed_hz;
977 ms += ms + 100; /* some tolerance */
978
979 ms = wait_for_completion_timeout(&master->xfer_completion,
980 msecs_to_jiffies(ms));
981 }
982
983 if (ms == 0) {
984 SPI_STATISTICS_INCREMENT_FIELD(statm,
985 timedout);
986 SPI_STATISTICS_INCREMENT_FIELD(stats,
987 timedout);
988 dev_err(&msg->spi->dev,
989 "SPI transfer timed out\n");
990 msg->status = -ETIMEDOUT;
991 }
992 } else {
993 if (xfer->len)
994 dev_err(&msg->spi->dev,
995 "Bufferless transfer has length %u\n",
996 xfer->len);
997 }
998
999 trace_spi_transfer_stop(msg, xfer);
1000
1001 if (msg->status != -EINPROGRESS)
1002 goto out;
1003
1004 if (xfer->delay_usecs)
1005 udelay(xfer->delay_usecs);
1006
1007 if (xfer->cs_change) {
1008 if (list_is_last(&xfer->transfer_list,
1009 &msg->transfers)) {
1010 keep_cs = true;
1011 } else {
1012 spi_set_cs(msg->spi, false);
1013 udelay(10);
1014 spi_set_cs(msg->spi, true);
1015 }
1016 }
1017
1018 msg->actual_length += xfer->len;
1019 }
1020
1021out:
1022 if (ret != 0 || !keep_cs)
1023 spi_set_cs(msg->spi, false);
1024
1025 if (msg->status == -EINPROGRESS)
1026 msg->status = ret;
1027
1028 if (msg->status && master->handle_err)
1029 master->handle_err(master, msg);
1030
1031 spi_res_release(master, msg);
1032
1033 spi_finalize_current_message(master);
1034
1035 return ret;
1036}
1037
1038/**
1039 * spi_finalize_current_transfer - report completion of a transfer
1040 * @master: the master reporting completion
1041 *
1042 * Called by SPI drivers using the core transfer_one_message()
1043 * implementation to notify it that the current interrupt driven
1044 * transfer has finished and the next one may be scheduled.
1045 */
1046void spi_finalize_current_transfer(struct spi_master *master)
1047{
1048 complete(&master->xfer_completion);
1049}
1050EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1051
1052/**
1053 * __spi_pump_messages - function which processes spi message queue
1054 * @master: master to process queue for
1055 * @in_kthread: true if we are in the context of the message pump thread
1056 * @bus_locked: true if the bus mutex is held when calling this function
1057 *
1058 * This function checks if there is any spi message in the queue that
1059 * needs processing and if so call out to the driver to initialize hardware
1060 * and transfer each message.
1061 *
1062 * Note that it is called both from the kthread itself and also from
1063 * inside spi_sync(); the queue extraction handling at the top of the
1064 * function should deal with this safely.
1065 */
1066static void __spi_pump_messages(struct spi_master *master, bool in_kthread,
1067 bool bus_locked)
1068{
1069 unsigned long flags;
1070 bool was_busy = false;
1071 int ret;
1072
1073 /* Lock queue */
1074 spin_lock_irqsave(&master->queue_lock, flags);
1075
1076 /* Make sure we are not already running a message */
1077 if (master->cur_msg) {
1078 spin_unlock_irqrestore(&master->queue_lock, flags);
1079 return;
1080 }
1081
1082 /* If another context is idling the device then defer */
1083 if (master->idling) {
1084 queue_kthread_work(&master->kworker, &master->pump_messages);
1085 spin_unlock_irqrestore(&master->queue_lock, flags);
1086 return;
1087 }
1088
1089 /* Check if the queue is idle */
1090 if (list_empty(&master->queue) || !master->running) {
1091 if (!master->busy) {
1092 spin_unlock_irqrestore(&master->queue_lock, flags);
1093 return;
1094 }
1095
1096 /* Only do teardown in the thread */
1097 if (!in_kthread) {
1098 queue_kthread_work(&master->kworker,
1099 &master->pump_messages);
1100 spin_unlock_irqrestore(&master->queue_lock, flags);
1101 return;
1102 }
1103
1104 master->busy = false;
1105 master->idling = true;
1106 spin_unlock_irqrestore(&master->queue_lock, flags);
1107
1108 kfree(master->dummy_rx);
1109 master->dummy_rx = NULL;
1110 kfree(master->dummy_tx);
1111 master->dummy_tx = NULL;
1112 if (master->unprepare_transfer_hardware &&
1113 master->unprepare_transfer_hardware(master))
1114 dev_err(&master->dev,
1115 "failed to unprepare transfer hardware\n");
1116 if (master->auto_runtime_pm) {
1117 pm_runtime_mark_last_busy(master->dev.parent);
1118 pm_runtime_put_autosuspend(master->dev.parent);
1119 }
1120 trace_spi_master_idle(master);
1121
1122 spin_lock_irqsave(&master->queue_lock, flags);
1123 master->idling = false;
1124 spin_unlock_irqrestore(&master->queue_lock, flags);
1125 return;
1126 }
1127
1128 /* Extract head of queue */
1129 master->cur_msg =
1130 list_first_entry(&master->queue, struct spi_message, queue);
1131
1132 list_del_init(&master->cur_msg->queue);
1133 if (master->busy)
1134 was_busy = true;
1135 else
1136 master->busy = true;
1137 spin_unlock_irqrestore(&master->queue_lock, flags);
1138
1139 if (!was_busy && master->auto_runtime_pm) {
1140 ret = pm_runtime_get_sync(master->dev.parent);
1141 if (ret < 0) {
1142 dev_err(&master->dev, "Failed to power device: %d\n",
1143 ret);
1144 return;
1145 }
1146 }
1147
1148 if (!was_busy)
1149 trace_spi_master_busy(master);
1150
1151 if (!was_busy && master->prepare_transfer_hardware) {
1152 ret = master->prepare_transfer_hardware(master);
1153 if (ret) {
1154 dev_err(&master->dev,
1155 "failed to prepare transfer hardware\n");
1156
1157 if (master->auto_runtime_pm)
1158 pm_runtime_put(master->dev.parent);
1159 return;
1160 }
1161 }
1162
1163 if (!bus_locked)
1164 mutex_lock(&master->bus_lock_mutex);
1165
1166 trace_spi_message_start(master->cur_msg);
1167
1168 if (master->prepare_message) {
1169 ret = master->prepare_message(master, master->cur_msg);
1170 if (ret) {
1171 dev_err(&master->dev,
1172 "failed to prepare message: %d\n", ret);
1173 master->cur_msg->status = ret;
1174 spi_finalize_current_message(master);
1175 goto out;
1176 }
1177 master->cur_msg_prepared = true;
1178 }
1179
1180 ret = spi_map_msg(master, master->cur_msg);
1181 if (ret) {
1182 master->cur_msg->status = ret;
1183 spi_finalize_current_message(master);
1184 goto out;
1185 }
1186
1187 ret = master->transfer_one_message(master, master->cur_msg);
1188 if (ret) {
1189 dev_err(&master->dev,
1190 "failed to transfer one message from queue\n");
1191 goto out;
1192 }
1193
1194out:
1195 if (!bus_locked)
1196 mutex_unlock(&master->bus_lock_mutex);
1197
1198 /* Prod the scheduler in case transfer_one() was busy waiting */
1199 if (!ret)
1200 cond_resched();
1201}
1202
1203/**
1204 * spi_pump_messages - kthread work function which processes spi message queue
1205 * @work: pointer to kthread work struct contained in the master struct
1206 */
1207static void spi_pump_messages(struct kthread_work *work)
1208{
1209 struct spi_master *master =
1210 container_of(work, struct spi_master, pump_messages);
1211
1212 __spi_pump_messages(master, true, master->bus_lock_flag);
1213}
1214
1215static int spi_init_queue(struct spi_master *master)
1216{
1217 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1218
1219 master->running = false;
1220 master->busy = false;
1221
1222 init_kthread_worker(&master->kworker);
1223 master->kworker_task = kthread_run(kthread_worker_fn,
1224 &master->kworker, "%s",
1225 dev_name(&master->dev));
1226 if (IS_ERR(master->kworker_task)) {
1227 dev_err(&master->dev, "failed to create message pump task\n");
1228 return PTR_ERR(master->kworker_task);
1229 }
1230 init_kthread_work(&master->pump_messages, spi_pump_messages);
1231
1232 /*
1233 * Master config will indicate if this controller should run the
1234 * message pump with high (realtime) priority to reduce the transfer
1235 * latency on the bus by minimising the delay between a transfer
1236 * request and the scheduling of the message pump thread. Without this
1237 * setting the message pump thread will remain at default priority.
1238 */
1239 if (master->rt) {
1240 dev_info(&master->dev,
1241 "will run message pump with realtime priority\n");
1242 sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m);
1243 }
1244
1245 return 0;
1246}
1247
1248/**
1249 * spi_get_next_queued_message() - called by driver to check for queued
1250 * messages
1251 * @master: the master to check for queued messages
1252 *
1253 * If there are more messages in the queue, the next message is returned from
1254 * this call.
1255 *
1256 * Return: the next message in the queue, else NULL if the queue is empty.
1257 */
1258struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1259{
1260 struct spi_message *next;
1261 unsigned long flags;
1262
1263 /* get a pointer to the next message, if any */
1264 spin_lock_irqsave(&master->queue_lock, flags);
1265 next = list_first_entry_or_null(&master->queue, struct spi_message,
1266 queue);
1267 spin_unlock_irqrestore(&master->queue_lock, flags);
1268
1269 return next;
1270}
1271EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1272
1273/**
1274 * spi_finalize_current_message() - the current message is complete
1275 * @master: the master to return the message to
1276 *
1277 * Called by the driver to notify the core that the message in the front of the
1278 * queue is complete and can be removed from the queue.
1279 */
1280void spi_finalize_current_message(struct spi_master *master)
1281{
1282 struct spi_message *mesg;
1283 unsigned long flags;
1284 int ret;
1285
1286 spin_lock_irqsave(&master->queue_lock, flags);
1287 mesg = master->cur_msg;
1288 spin_unlock_irqrestore(&master->queue_lock, flags);
1289
1290 spi_unmap_msg(master, mesg);
1291
1292 if (master->cur_msg_prepared && master->unprepare_message) {
1293 ret = master->unprepare_message(master, mesg);
1294 if (ret) {
1295 dev_err(&master->dev,
1296 "failed to unprepare message: %d\n", ret);
1297 }
1298 }
1299
1300 spin_lock_irqsave(&master->queue_lock, flags);
1301 master->cur_msg = NULL;
1302 master->cur_msg_prepared = false;
1303 queue_kthread_work(&master->kworker, &master->pump_messages);
1304 spin_unlock_irqrestore(&master->queue_lock, flags);
1305
1306 trace_spi_message_done(mesg);
1307
1308 mesg->state = NULL;
1309 if (mesg->complete)
1310 mesg->complete(mesg->context);
1311}
1312EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1313
1314static int spi_start_queue(struct spi_master *master)
1315{
1316 unsigned long flags;
1317
1318 spin_lock_irqsave(&master->queue_lock, flags);
1319
1320 if (master->running || master->busy) {
1321 spin_unlock_irqrestore(&master->queue_lock, flags);
1322 return -EBUSY;
1323 }
1324
1325 master->running = true;
1326 master->cur_msg = NULL;
1327 spin_unlock_irqrestore(&master->queue_lock, flags);
1328
1329 queue_kthread_work(&master->kworker, &master->pump_messages);
1330
1331 return 0;
1332}
1333
1334static int spi_stop_queue(struct spi_master *master)
1335{
1336 unsigned long flags;
1337 unsigned limit = 500;
1338 int ret = 0;
1339
1340 spin_lock_irqsave(&master->queue_lock, flags);
1341
1342 /*
1343 * This is a bit lame, but is optimized for the common execution path.
1344 * A wait_queue on the master->busy could be used, but then the common
1345 * execution path (pump_messages) would be required to call wake_up or
1346 * friends on every SPI message. Do this instead.
1347 */
1348 while ((!list_empty(&master->queue) || master->busy) && limit--) {
1349 spin_unlock_irqrestore(&master->queue_lock, flags);
1350 usleep_range(10000, 11000);
1351 spin_lock_irqsave(&master->queue_lock, flags);
1352 }
1353
1354 if (!list_empty(&master->queue) || master->busy)
1355 ret = -EBUSY;
1356 else
1357 master->running = false;
1358
1359 spin_unlock_irqrestore(&master->queue_lock, flags);
1360
1361 if (ret) {
1362 dev_warn(&master->dev,
1363 "could not stop message queue\n");
1364 return ret;
1365 }
1366 return ret;
1367}
1368
1369static int spi_destroy_queue(struct spi_master *master)
1370{
1371 int ret;
1372
1373 ret = spi_stop_queue(master);
1374
1375 /*
1376 * flush_kthread_worker will block until all work is done.
1377 * If the reason that stop_queue timed out is that the work will never
1378 * finish, then it does no good to call flush/stop thread, so
1379 * return anyway.
1380 */
1381 if (ret) {
1382 dev_err(&master->dev, "problem destroying queue\n");
1383 return ret;
1384 }
1385
1386 flush_kthread_worker(&master->kworker);
1387 kthread_stop(master->kworker_task);
1388
1389 return 0;
1390}
1391
1392static int __spi_queued_transfer(struct spi_device *spi,
1393 struct spi_message *msg,
1394 bool need_pump)
1395{
1396 struct spi_master *master = spi->master;
1397 unsigned long flags;
1398
1399 spin_lock_irqsave(&master->queue_lock, flags);
1400
1401 if (!master->running) {
1402 spin_unlock_irqrestore(&master->queue_lock, flags);
1403 return -ESHUTDOWN;
1404 }
1405 msg->actual_length = 0;
1406 msg->status = -EINPROGRESS;
1407
1408 list_add_tail(&msg->queue, &master->queue);
1409 if (!master->busy && need_pump)
1410 queue_kthread_work(&master->kworker, &master->pump_messages);
1411
1412 spin_unlock_irqrestore(&master->queue_lock, flags);
1413 return 0;
1414}
1415
1416/**
1417 * spi_queued_transfer - transfer function for queued transfers
1418 * @spi: spi device which is requesting transfer
1419 * @msg: spi message which is to handled is queued to driver queue
1420 *
1421 * Return: zero on success, else a negative error code.
1422 */
1423static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1424{
1425 return __spi_queued_transfer(spi, msg, true);
1426}
1427
1428static int spi_master_initialize_queue(struct spi_master *master)
1429{
1430 int ret;
1431
1432 master->transfer = spi_queued_transfer;
1433 if (!master->transfer_one_message)
1434 master->transfer_one_message = spi_transfer_one_message;
1435
1436 /* Initialize and start queue */
1437 ret = spi_init_queue(master);
1438 if (ret) {
1439 dev_err(&master->dev, "problem initializing queue\n");
1440 goto err_init_queue;
1441 }
1442 master->queued = true;
1443 ret = spi_start_queue(master);
1444 if (ret) {
1445 dev_err(&master->dev, "problem starting queue\n");
1446 goto err_start_queue;
1447 }
1448
1449 return 0;
1450
1451err_start_queue:
1452 spi_destroy_queue(master);
1453err_init_queue:
1454 return ret;
1455}
1456
1457/*-------------------------------------------------------------------------*/
1458
1459#if defined(CONFIG_OF)
1460static struct spi_device *
1461of_register_spi_device(struct spi_master *master, struct device_node *nc)
1462{
1463 struct spi_device *spi;
1464 int rc;
1465 u32 value;
1466
1467 /* Alloc an spi_device */
1468 spi = spi_alloc_device(master);
1469 if (!spi) {
1470 dev_err(&master->dev, "spi_device alloc error for %s\n",
1471 nc->full_name);
1472 rc = -ENOMEM;
1473 goto err_out;
1474 }
1475
1476 /* Select device driver */
1477 rc = of_modalias_node(nc, spi->modalias,
1478 sizeof(spi->modalias));
1479 if (rc < 0) {
1480 dev_err(&master->dev, "cannot find modalias for %s\n",
1481 nc->full_name);
1482 goto err_out;
1483 }
1484
1485 /* Device address */
1486 rc = of_property_read_u32(nc, "reg", &value);
1487 if (rc) {
1488 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1489 nc->full_name, rc);
1490 goto err_out;
1491 }
1492 spi->chip_select = value;
1493
1494 /* Mode (clock phase/polarity/etc.) */
1495 if (of_find_property(nc, "spi-cpha", NULL))
1496 spi->mode |= SPI_CPHA;
1497 if (of_find_property(nc, "spi-cpol", NULL))
1498 spi->mode |= SPI_CPOL;
1499 if (of_find_property(nc, "spi-cs-high", NULL))
1500 spi->mode |= SPI_CS_HIGH;
1501 if (of_find_property(nc, "spi-3wire", NULL))
1502 spi->mode |= SPI_3WIRE;
1503 if (of_find_property(nc, "spi-lsb-first", NULL))
1504 spi->mode |= SPI_LSB_FIRST;
1505
1506 /* Device DUAL/QUAD mode */
1507 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1508 switch (value) {
1509 case 1:
1510 break;
1511 case 2:
1512 spi->mode |= SPI_TX_DUAL;
1513 break;
1514 case 4:
1515 spi->mode |= SPI_TX_QUAD;
1516 break;
1517 default:
1518 dev_warn(&master->dev,
1519 "spi-tx-bus-width %d not supported\n",
1520 value);
1521 break;
1522 }
1523 }
1524
1525 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1526 switch (value) {
1527 case 1:
1528 break;
1529 case 2:
1530 spi->mode |= SPI_RX_DUAL;
1531 break;
1532 case 4:
1533 spi->mode |= SPI_RX_QUAD;
1534 break;
1535 default:
1536 dev_warn(&master->dev,
1537 "spi-rx-bus-width %d not supported\n",
1538 value);
1539 break;
1540 }
1541 }
1542
1543 /* Device speed */
1544 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1545 if (rc) {
1546 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1547 nc->full_name, rc);
1548 goto err_out;
1549 }
1550 spi->max_speed_hz = value;
1551
1552 /* Store a pointer to the node in the device structure */
1553 of_node_get(nc);
1554 spi->dev.of_node = nc;
1555
1556 /* Register the new device */
1557 rc = spi_add_device(spi);
1558 if (rc) {
1559 dev_err(&master->dev, "spi_device register error %s\n",
1560 nc->full_name);
1561 goto err_out;
1562 }
1563
1564 return spi;
1565
1566err_out:
1567 spi_dev_put(spi);
1568 return ERR_PTR(rc);
1569}
1570
1571/**
1572 * of_register_spi_devices() - Register child devices onto the SPI bus
1573 * @master: Pointer to spi_master device
1574 *
1575 * Registers an spi_device for each child node of master node which has a 'reg'
1576 * property.
1577 */
1578static void of_register_spi_devices(struct spi_master *master)
1579{
1580 struct spi_device *spi;
1581 struct device_node *nc;
1582
1583 if (!master->dev.of_node)
1584 return;
1585
1586 for_each_available_child_of_node(master->dev.of_node, nc) {
1587 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1588 continue;
1589 spi = of_register_spi_device(master, nc);
1590 if (IS_ERR(spi))
1591 dev_warn(&master->dev, "Failed to create SPI device for %s\n",
1592 nc->full_name);
1593 }
1594}
1595#else
1596static void of_register_spi_devices(struct spi_master *master) { }
1597#endif
1598
1599#ifdef CONFIG_ACPI
1600static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1601{
1602 struct spi_device *spi = data;
1603 struct spi_master *master = spi->master;
1604
1605 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1606 struct acpi_resource_spi_serialbus *sb;
1607
1608 sb = &ares->data.spi_serial_bus;
1609 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1610 /*
1611 * ACPI DeviceSelection numbering is handled by the
1612 * host controller driver in Windows and can vary
1613 * from driver to driver. In Linux we always expect
1614 * 0 .. max - 1 so we need to ask the driver to
1615 * translate between the two schemes.
1616 */
1617 if (master->fw_translate_cs) {
1618 int cs = master->fw_translate_cs(master,
1619 sb->device_selection);
1620 if (cs < 0)
1621 return cs;
1622 spi->chip_select = cs;
1623 } else {
1624 spi->chip_select = sb->device_selection;
1625 }
1626
1627 spi->max_speed_hz = sb->connection_speed;
1628
1629 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1630 spi->mode |= SPI_CPHA;
1631 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1632 spi->mode |= SPI_CPOL;
1633 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1634 spi->mode |= SPI_CS_HIGH;
1635 }
1636 } else if (spi->irq < 0) {
1637 struct resource r;
1638
1639 if (acpi_dev_resource_interrupt(ares, 0, &r))
1640 spi->irq = r.start;
1641 }
1642
1643 /* Always tell the ACPI core to skip this resource */
1644 return 1;
1645}
1646
1647static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1648 void *data, void **return_value)
1649{
1650 struct spi_master *master = data;
1651 struct list_head resource_list;
1652 struct acpi_device *adev;
1653 struct spi_device *spi;
1654 int ret;
1655
1656 if (acpi_bus_get_device(handle, &adev))
1657 return AE_OK;
1658 if (acpi_bus_get_status(adev) || !adev->status.present)
1659 return AE_OK;
1660
1661 spi = spi_alloc_device(master);
1662 if (!spi) {
1663 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1664 dev_name(&adev->dev));
1665 return AE_NO_MEMORY;
1666 }
1667
1668 ACPI_COMPANION_SET(&spi->dev, adev);
1669 spi->irq = -1;
1670
1671 INIT_LIST_HEAD(&resource_list);
1672 ret = acpi_dev_get_resources(adev, &resource_list,
1673 acpi_spi_add_resource, spi);
1674 acpi_dev_free_resource_list(&resource_list);
1675
1676 if (ret < 0 || !spi->max_speed_hz) {
1677 spi_dev_put(spi);
1678 return AE_OK;
1679 }
1680
1681 if (spi->irq < 0)
1682 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1683
1684 adev->power.flags.ignore_parent = true;
1685 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
1686 if (spi_add_device(spi)) {
1687 adev->power.flags.ignore_parent = false;
1688 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1689 dev_name(&adev->dev));
1690 spi_dev_put(spi);
1691 }
1692
1693 return AE_OK;
1694}
1695
1696static void acpi_register_spi_devices(struct spi_master *master)
1697{
1698 acpi_status status;
1699 acpi_handle handle;
1700
1701 handle = ACPI_HANDLE(master->dev.parent);
1702 if (!handle)
1703 return;
1704
1705 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1706 acpi_spi_add_device, NULL,
1707 master, NULL);
1708 if (ACPI_FAILURE(status))
1709 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1710}
1711#else
1712static inline void acpi_register_spi_devices(struct spi_master *master) {}
1713#endif /* CONFIG_ACPI */
1714
1715static void spi_master_release(struct device *dev)
1716{
1717 struct spi_master *master;
1718
1719 master = container_of(dev, struct spi_master, dev);
1720 kfree(master);
1721}
1722
1723static struct class spi_master_class = {
1724 .name = "spi_master",
1725 .owner = THIS_MODULE,
1726 .dev_release = spi_master_release,
1727 .dev_groups = spi_master_groups,
1728};
1729
1730
1731/**
1732 * spi_alloc_master - allocate SPI master controller
1733 * @dev: the controller, possibly using the platform_bus
1734 * @size: how much zeroed driver-private data to allocate; the pointer to this
1735 * memory is in the driver_data field of the returned device,
1736 * accessible with spi_master_get_devdata().
1737 * Context: can sleep
1738 *
1739 * This call is used only by SPI master controller drivers, which are the
1740 * only ones directly touching chip registers. It's how they allocate
1741 * an spi_master structure, prior to calling spi_register_master().
1742 *
1743 * This must be called from context that can sleep.
1744 *
1745 * The caller is responsible for assigning the bus number and initializing
1746 * the master's methods before calling spi_register_master(); and (after errors
1747 * adding the device) calling spi_master_put() to prevent a memory leak.
1748 *
1749 * Return: the SPI master structure on success, else NULL.
1750 */
1751struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
1752{
1753 struct spi_master *master;
1754
1755 if (!dev)
1756 return NULL;
1757
1758 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
1759 if (!master)
1760 return NULL;
1761
1762 device_initialize(&master->dev);
1763 master->bus_num = -1;
1764 master->num_chipselect = 1;
1765 master->dev.class = &spi_master_class;
1766 master->dev.parent = dev;
1767 spi_master_set_devdata(master, &master[1]);
1768
1769 return master;
1770}
1771EXPORT_SYMBOL_GPL(spi_alloc_master);
1772
1773#ifdef CONFIG_OF
1774static int of_spi_register_master(struct spi_master *master)
1775{
1776 int nb, i, *cs;
1777 struct device_node *np = master->dev.of_node;
1778
1779 if (!np)
1780 return 0;
1781
1782 nb = of_gpio_named_count(np, "cs-gpios");
1783 master->num_chipselect = max_t(int, nb, master->num_chipselect);
1784
1785 /* Return error only for an incorrectly formed cs-gpios property */
1786 if (nb == 0 || nb == -ENOENT)
1787 return 0;
1788 else if (nb < 0)
1789 return nb;
1790
1791 cs = devm_kzalloc(&master->dev,
1792 sizeof(int) * master->num_chipselect,
1793 GFP_KERNEL);
1794 master->cs_gpios = cs;
1795
1796 if (!master->cs_gpios)
1797 return -ENOMEM;
1798
1799 for (i = 0; i < master->num_chipselect; i++)
1800 cs[i] = -ENOENT;
1801
1802 for (i = 0; i < nb; i++)
1803 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1804
1805 return 0;
1806}
1807#else
1808static int of_spi_register_master(struct spi_master *master)
1809{
1810 return 0;
1811}
1812#endif
1813
1814/**
1815 * spi_register_master - register SPI master controller
1816 * @master: initialized master, originally from spi_alloc_master()
1817 * Context: can sleep
1818 *
1819 * SPI master controllers connect to their drivers using some non-SPI bus,
1820 * such as the platform bus. The final stage of probe() in that code
1821 * includes calling spi_register_master() to hook up to this SPI bus glue.
1822 *
1823 * SPI controllers use board specific (often SOC specific) bus numbers,
1824 * and board-specific addressing for SPI devices combines those numbers
1825 * with chip select numbers. Since SPI does not directly support dynamic
1826 * device identification, boards need configuration tables telling which
1827 * chip is at which address.
1828 *
1829 * This must be called from context that can sleep. It returns zero on
1830 * success, else a negative error code (dropping the master's refcount).
1831 * After a successful return, the caller is responsible for calling
1832 * spi_unregister_master().
1833 *
1834 * Return: zero on success, else a negative error code.
1835 */
1836int spi_register_master(struct spi_master *master)
1837{
1838 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
1839 struct device *dev = master->dev.parent;
1840 struct boardinfo *bi;
1841 int status = -ENODEV;
1842 int dynamic = 0;
1843
1844 if (!dev)
1845 return -ENODEV;
1846
1847 status = of_spi_register_master(master);
1848 if (status)
1849 return status;
1850
1851 /* even if it's just one always-selected device, there must
1852 * be at least one chipselect
1853 */
1854 if (master->num_chipselect == 0)
1855 return -EINVAL;
1856
1857 if ((master->bus_num < 0) && master->dev.of_node)
1858 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1859
1860 /* convention: dynamically assigned bus IDs count down from the max */
1861 if (master->bus_num < 0) {
1862 /* FIXME switch to an IDR based scheme, something like
1863 * I2C now uses, so we can't run out of "dynamic" IDs
1864 */
1865 master->bus_num = atomic_dec_return(&dyn_bus_id);
1866 dynamic = 1;
1867 }
1868
1869 INIT_LIST_HEAD(&master->queue);
1870 spin_lock_init(&master->queue_lock);
1871 spin_lock_init(&master->bus_lock_spinlock);
1872 mutex_init(&master->bus_lock_mutex);
1873 master->bus_lock_flag = 0;
1874 init_completion(&master->xfer_completion);
1875 if (!master->max_dma_len)
1876 master->max_dma_len = INT_MAX;
1877
1878 /* register the device, then userspace will see it.
1879 * registration fails if the bus ID is in use.
1880 */
1881 dev_set_name(&master->dev, "spi%u", master->bus_num);
1882 status = device_add(&master->dev);
1883 if (status < 0)
1884 goto done;
1885 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
1886 dynamic ? " (dynamic)" : "");
1887
1888 /* If we're using a queued driver, start the queue */
1889 if (master->transfer)
1890 dev_info(dev, "master is unqueued, this is deprecated\n");
1891 else {
1892 status = spi_master_initialize_queue(master);
1893 if (status) {
1894 device_del(&master->dev);
1895 goto done;
1896 }
1897 }
1898 /* add statistics */
1899 spin_lock_init(&master->statistics.lock);
1900
1901 mutex_lock(&board_lock);
1902 list_add_tail(&master->list, &spi_master_list);
1903 list_for_each_entry(bi, &board_list, list)
1904 spi_match_master_to_boardinfo(master, &bi->board_info);
1905 mutex_unlock(&board_lock);
1906
1907 /* Register devices from the device tree and ACPI */
1908 of_register_spi_devices(master);
1909 acpi_register_spi_devices(master);
1910done:
1911 return status;
1912}
1913EXPORT_SYMBOL_GPL(spi_register_master);
1914
1915static void devm_spi_unregister(struct device *dev, void *res)
1916{
1917 spi_unregister_master(*(struct spi_master **)res);
1918}
1919
1920/**
1921 * dev_spi_register_master - register managed SPI master controller
1922 * @dev: device managing SPI master
1923 * @master: initialized master, originally from spi_alloc_master()
1924 * Context: can sleep
1925 *
1926 * Register a SPI device as with spi_register_master() which will
1927 * automatically be unregister
1928 *
1929 * Return: zero on success, else a negative error code.
1930 */
1931int devm_spi_register_master(struct device *dev, struct spi_master *master)
1932{
1933 struct spi_master **ptr;
1934 int ret;
1935
1936 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
1937 if (!ptr)
1938 return -ENOMEM;
1939
1940 ret = spi_register_master(master);
1941 if (!ret) {
1942 *ptr = master;
1943 devres_add(dev, ptr);
1944 } else {
1945 devres_free(ptr);
1946 }
1947
1948 return ret;
1949}
1950EXPORT_SYMBOL_GPL(devm_spi_register_master);
1951
1952static int __unregister(struct device *dev, void *null)
1953{
1954 spi_unregister_device(to_spi_device(dev));
1955 return 0;
1956}
1957
1958/**
1959 * spi_unregister_master - unregister SPI master controller
1960 * @master: the master being unregistered
1961 * Context: can sleep
1962 *
1963 * This call is used only by SPI master controller drivers, which are the
1964 * only ones directly touching chip registers.
1965 *
1966 * This must be called from context that can sleep.
1967 */
1968void spi_unregister_master(struct spi_master *master)
1969{
1970 int dummy;
1971
1972 if (master->queued) {
1973 if (spi_destroy_queue(master))
1974 dev_err(&master->dev, "queue remove failed\n");
1975 }
1976
1977 mutex_lock(&board_lock);
1978 list_del(&master->list);
1979 mutex_unlock(&board_lock);
1980
1981 dummy = device_for_each_child(&master->dev, NULL, __unregister);
1982 device_unregister(&master->dev);
1983}
1984EXPORT_SYMBOL_GPL(spi_unregister_master);
1985
1986int spi_master_suspend(struct spi_master *master)
1987{
1988 int ret;
1989
1990 /* Basically no-ops for non-queued masters */
1991 if (!master->queued)
1992 return 0;
1993
1994 ret = spi_stop_queue(master);
1995 if (ret)
1996 dev_err(&master->dev, "queue stop failed\n");
1997
1998 return ret;
1999}
2000EXPORT_SYMBOL_GPL(spi_master_suspend);
2001
2002int spi_master_resume(struct spi_master *master)
2003{
2004 int ret;
2005
2006 if (!master->queued)
2007 return 0;
2008
2009 ret = spi_start_queue(master);
2010 if (ret)
2011 dev_err(&master->dev, "queue restart failed\n");
2012
2013 return ret;
2014}
2015EXPORT_SYMBOL_GPL(spi_master_resume);
2016
2017static int __spi_master_match(struct device *dev, const void *data)
2018{
2019 struct spi_master *m;
2020 const u16 *bus_num = data;
2021
2022 m = container_of(dev, struct spi_master, dev);
2023 return m->bus_num == *bus_num;
2024}
2025
2026/**
2027 * spi_busnum_to_master - look up master associated with bus_num
2028 * @bus_num: the master's bus number
2029 * Context: can sleep
2030 *
2031 * This call may be used with devices that are registered after
2032 * arch init time. It returns a refcounted pointer to the relevant
2033 * spi_master (which the caller must release), or NULL if there is
2034 * no such master registered.
2035 *
2036 * Return: the SPI master structure on success, else NULL.
2037 */
2038struct spi_master *spi_busnum_to_master(u16 bus_num)
2039{
2040 struct device *dev;
2041 struct spi_master *master = NULL;
2042
2043 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2044 __spi_master_match);
2045 if (dev)
2046 master = container_of(dev, struct spi_master, dev);
2047 /* reference got in class_find_device */
2048 return master;
2049}
2050EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2051
2052/*-------------------------------------------------------------------------*/
2053
2054/* Core methods for SPI resource management */
2055
2056/**
2057 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2058 * during the processing of a spi_message while using
2059 * spi_transfer_one
2060 * @spi: the spi device for which we allocate memory
2061 * @release: the release code to execute for this resource
2062 * @size: size to alloc and return
2063 * @gfp: GFP allocation flags
2064 *
2065 * Return: the pointer to the allocated data
2066 *
2067 * This may get enhanced in the future to allocate from a memory pool
2068 * of the @spi_device or @spi_master to avoid repeated allocations.
2069 */
2070void *spi_res_alloc(struct spi_device *spi,
2071 spi_res_release_t release,
2072 size_t size, gfp_t gfp)
2073{
2074 struct spi_res *sres;
2075
2076 sres = kzalloc(sizeof(*sres) + size, gfp);
2077 if (!sres)
2078 return NULL;
2079
2080 INIT_LIST_HEAD(&sres->entry);
2081 sres->release = release;
2082
2083 return sres->data;
2084}
2085EXPORT_SYMBOL_GPL(spi_res_alloc);
2086
2087/**
2088 * spi_res_free - free an spi resource
2089 * @res: pointer to the custom data of a resource
2090 *
2091 */
2092void spi_res_free(void *res)
2093{
2094 struct spi_res *sres = container_of(res, struct spi_res, data);
2095
2096 if (!res)
2097 return;
2098
2099 WARN_ON(!list_empty(&sres->entry));
2100 kfree(sres);
2101}
2102EXPORT_SYMBOL_GPL(spi_res_free);
2103
2104/**
2105 * spi_res_add - add a spi_res to the spi_message
2106 * @message: the spi message
2107 * @res: the spi_resource
2108 */
2109void spi_res_add(struct spi_message *message, void *res)
2110{
2111 struct spi_res *sres = container_of(res, struct spi_res, data);
2112
2113 WARN_ON(!list_empty(&sres->entry));
2114 list_add_tail(&sres->entry, &message->resources);
2115}
2116EXPORT_SYMBOL_GPL(spi_res_add);
2117
2118/**
2119 * spi_res_release - release all spi resources for this message
2120 * @master: the @spi_master
2121 * @message: the @spi_message
2122 */
2123void spi_res_release(struct spi_master *master,
2124 struct spi_message *message)
2125{
2126 struct spi_res *res;
2127
2128 while (!list_empty(&message->resources)) {
2129 res = list_last_entry(&message->resources,
2130 struct spi_res, entry);
2131
2132 if (res->release)
2133 res->release(master, message, res->data);
2134
2135 list_del(&res->entry);
2136
2137 kfree(res);
2138 }
2139}
2140EXPORT_SYMBOL_GPL(spi_res_release);
2141
2142/*-------------------------------------------------------------------------*/
2143
2144/* Core methods for spi_message alterations */
2145
2146static void __spi_replace_transfers_release(struct spi_master *master,
2147 struct spi_message *msg,
2148 void *res)
2149{
2150 struct spi_replaced_transfers *rxfer = res;
2151 size_t i;
2152
2153 /* call extra callback if requested */
2154 if (rxfer->release)
2155 rxfer->release(master, msg, res);
2156
2157 /* insert replaced transfers back into the message */
2158 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2159
2160 /* remove the formerly inserted entries */
2161 for (i = 0; i < rxfer->inserted; i++)
2162 list_del(&rxfer->inserted_transfers[i].transfer_list);
2163}
2164
2165/**
2166 * spi_replace_transfers - replace transfers with several transfers
2167 * and register change with spi_message.resources
2168 * @msg: the spi_message we work upon
2169 * @xfer_first: the first spi_transfer we want to replace
2170 * @remove: number of transfers to remove
2171 * @insert: the number of transfers we want to insert instead
2172 * @release: extra release code necessary in some circumstances
2173 * @extradatasize: extra data to allocate (with alignment guarantees
2174 * of struct @spi_transfer)
2175 * @gfp: gfp flags
2176 *
2177 * Returns: pointer to @spi_replaced_transfers,
2178 * PTR_ERR(...) in case of errors.
2179 */
2180struct spi_replaced_transfers *spi_replace_transfers(
2181 struct spi_message *msg,
2182 struct spi_transfer *xfer_first,
2183 size_t remove,
2184 size_t insert,
2185 spi_replaced_release_t release,
2186 size_t extradatasize,
2187 gfp_t gfp)
2188{
2189 struct spi_replaced_transfers *rxfer;
2190 struct spi_transfer *xfer;
2191 size_t i;
2192
2193 /* allocate the structure using spi_res */
2194 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2195 insert * sizeof(struct spi_transfer)
2196 + sizeof(struct spi_replaced_transfers)
2197 + extradatasize,
2198 gfp);
2199 if (!rxfer)
2200 return ERR_PTR(-ENOMEM);
2201
2202 /* the release code to invoke before running the generic release */
2203 rxfer->release = release;
2204
2205 /* assign extradata */
2206 if (extradatasize)
2207 rxfer->extradata =
2208 &rxfer->inserted_transfers[insert];
2209
2210 /* init the replaced_transfers list */
2211 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2212
2213 /* assign the list_entry after which we should reinsert
2214 * the @replaced_transfers - it may be spi_message.messages!
2215 */
2216 rxfer->replaced_after = xfer_first->transfer_list.prev;
2217
2218 /* remove the requested number of transfers */
2219 for (i = 0; i < remove; i++) {
2220 /* if the entry after replaced_after it is msg->transfers
2221 * then we have been requested to remove more transfers
2222 * than are in the list
2223 */
2224 if (rxfer->replaced_after->next == &msg->transfers) {
2225 dev_err(&msg->spi->dev,
2226 "requested to remove more spi_transfers than are available\n");
2227 /* insert replaced transfers back into the message */
2228 list_splice(&rxfer->replaced_transfers,
2229 rxfer->replaced_after);
2230
2231 /* free the spi_replace_transfer structure */
2232 spi_res_free(rxfer);
2233
2234 /* and return with an error */
2235 return ERR_PTR(-EINVAL);
2236 }
2237
2238 /* remove the entry after replaced_after from list of
2239 * transfers and add it to list of replaced_transfers
2240 */
2241 list_move_tail(rxfer->replaced_after->next,
2242 &rxfer->replaced_transfers);
2243 }
2244
2245 /* create copy of the given xfer with identical settings
2246 * based on the first transfer to get removed
2247 */
2248 for (i = 0; i < insert; i++) {
2249 /* we need to run in reverse order */
2250 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2251
2252 /* copy all spi_transfer data */
2253 memcpy(xfer, xfer_first, sizeof(*xfer));
2254
2255 /* add to list */
2256 list_add(&xfer->transfer_list, rxfer->replaced_after);
2257
2258 /* clear cs_change and delay_usecs for all but the last */
2259 if (i) {
2260 xfer->cs_change = false;
2261 xfer->delay_usecs = 0;
2262 }
2263 }
2264
2265 /* set up inserted */
2266 rxfer->inserted = insert;
2267
2268 /* and register it with spi_res/spi_message */
2269 spi_res_add(msg, rxfer);
2270
2271 return rxfer;
2272}
2273EXPORT_SYMBOL_GPL(spi_replace_transfers);
2274
2275static int __spi_split_transfer_maxsize(struct spi_master *master,
2276 struct spi_message *msg,
2277 struct spi_transfer **xferp,
2278 size_t maxsize,
2279 gfp_t gfp)
2280{
2281 struct spi_transfer *xfer = *xferp, *xfers;
2282 struct spi_replaced_transfers *srt;
2283 size_t offset;
2284 size_t count, i;
2285
2286 /* warn once about this fact that we are splitting a transfer */
2287 dev_warn_once(&msg->spi->dev,
2288 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2289 xfer->len, maxsize);
2290
2291 /* calculate how many we have to replace */
2292 count = DIV_ROUND_UP(xfer->len, maxsize);
2293
2294 /* create replacement */
2295 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
2296 if (IS_ERR(srt))
2297 return PTR_ERR(srt);
2298 xfers = srt->inserted_transfers;
2299
2300 /* now handle each of those newly inserted spi_transfers
2301 * note that the replacements spi_transfers all are preset
2302 * to the same values as *xferp, so tx_buf, rx_buf and len
2303 * are all identical (as well as most others)
2304 * so we just have to fix up len and the pointers.
2305 *
2306 * this also includes support for the depreciated
2307 * spi_message.is_dma_mapped interface
2308 */
2309
2310 /* the first transfer just needs the length modified, so we
2311 * run it outside the loop
2312 */
2313 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
2314
2315 /* all the others need rx_buf/tx_buf also set */
2316 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2317 /* update rx_buf, tx_buf and dma */
2318 if (xfers[i].rx_buf)
2319 xfers[i].rx_buf += offset;
2320 if (xfers[i].rx_dma)
2321 xfers[i].rx_dma += offset;
2322 if (xfers[i].tx_buf)
2323 xfers[i].tx_buf += offset;
2324 if (xfers[i].tx_dma)
2325 xfers[i].tx_dma += offset;
2326
2327 /* update length */
2328 xfers[i].len = min(maxsize, xfers[i].len - offset);
2329 }
2330
2331 /* we set up xferp to the last entry we have inserted,
2332 * so that we skip those already split transfers
2333 */
2334 *xferp = &xfers[count - 1];
2335
2336 /* increment statistics counters */
2337 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2338 transfers_split_maxsize);
2339 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2340 transfers_split_maxsize);
2341
2342 return 0;
2343}
2344
2345/**
2346 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2347 * when an individual transfer exceeds a
2348 * certain size
2349 * @master: the @spi_master for this transfer
2350 * @msg: the @spi_message to transform
2351 * @maxsize: the maximum when to apply this
2352 * @gfp: GFP allocation flags
2353 *
2354 * Return: status of transformation
2355 */
2356int spi_split_transfers_maxsize(struct spi_master *master,
2357 struct spi_message *msg,
2358 size_t maxsize,
2359 gfp_t gfp)
2360{
2361 struct spi_transfer *xfer;
2362 int ret;
2363
2364 /* iterate over the transfer_list,
2365 * but note that xfer is advanced to the last transfer inserted
2366 * to avoid checking sizes again unnecessarily (also xfer does
2367 * potentiall belong to a different list by the time the
2368 * replacement has happened
2369 */
2370 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2371 if (xfer->len > maxsize) {
2372 ret = __spi_split_transfer_maxsize(
2373 master, msg, &xfer, maxsize, gfp);
2374 if (ret)
2375 return ret;
2376 }
2377 }
2378
2379 return 0;
2380}
2381EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2382
2383/*-------------------------------------------------------------------------*/
2384
2385/* Core methods for SPI master protocol drivers. Some of the
2386 * other core methods are currently defined as inline functions.
2387 */
2388
2389static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2390{
2391 if (master->bits_per_word_mask) {
2392 /* Only 32 bits fit in the mask */
2393 if (bits_per_word > 32)
2394 return -EINVAL;
2395 if (!(master->bits_per_word_mask &
2396 SPI_BPW_MASK(bits_per_word)))
2397 return -EINVAL;
2398 }
2399
2400 return 0;
2401}
2402
2403/**
2404 * spi_setup - setup SPI mode and clock rate
2405 * @spi: the device whose settings are being modified
2406 * Context: can sleep, and no requests are queued to the device
2407 *
2408 * SPI protocol drivers may need to update the transfer mode if the
2409 * device doesn't work with its default. They may likewise need
2410 * to update clock rates or word sizes from initial values. This function
2411 * changes those settings, and must be called from a context that can sleep.
2412 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2413 * effect the next time the device is selected and data is transferred to
2414 * or from it. When this function returns, the spi device is deselected.
2415 *
2416 * Note that this call will fail if the protocol driver specifies an option
2417 * that the underlying controller or its driver does not support. For
2418 * example, not all hardware supports wire transfers using nine bit words,
2419 * LSB-first wire encoding, or active-high chipselects.
2420 *
2421 * Return: zero on success, else a negative error code.
2422 */
2423int spi_setup(struct spi_device *spi)
2424{
2425 unsigned bad_bits, ugly_bits;
2426 int status;
2427
2428 /* check mode to prevent that DUAL and QUAD set at the same time
2429 */
2430 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2431 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2432 dev_err(&spi->dev,
2433 "setup: can not select dual and quad at the same time\n");
2434 return -EINVAL;
2435 }
2436 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2437 */
2438 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2439 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2440 return -EINVAL;
2441 /* help drivers fail *cleanly* when they need options
2442 * that aren't supported with their current master
2443 */
2444 bad_bits = spi->mode & ~spi->master->mode_bits;
2445 ugly_bits = bad_bits &
2446 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2447 if (ugly_bits) {
2448 dev_warn(&spi->dev,
2449 "setup: ignoring unsupported mode bits %x\n",
2450 ugly_bits);
2451 spi->mode &= ~ugly_bits;
2452 bad_bits &= ~ugly_bits;
2453 }
2454 if (bad_bits) {
2455 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
2456 bad_bits);
2457 return -EINVAL;
2458 }
2459
2460 if (!spi->bits_per_word)
2461 spi->bits_per_word = 8;
2462
2463 status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2464 if (status)
2465 return status;
2466
2467 if (!spi->max_speed_hz)
2468 spi->max_speed_hz = spi->master->max_speed_hz;
2469
2470 if (spi->master->setup)
2471 status = spi->master->setup(spi);
2472
2473 spi_set_cs(spi, false);
2474
2475 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2476 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2477 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2478 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2479 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2480 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2481 spi->bits_per_word, spi->max_speed_hz,
2482 status);
2483
2484 return status;
2485}
2486EXPORT_SYMBOL_GPL(spi_setup);
2487
2488static int __spi_validate(struct spi_device *spi, struct spi_message *message)
2489{
2490 struct spi_master *master = spi->master;
2491 struct spi_transfer *xfer;
2492 int w_size;
2493
2494 if (list_empty(&message->transfers))
2495 return -EINVAL;
2496
2497 /* Half-duplex links include original MicroWire, and ones with
2498 * only one data pin like SPI_3WIRE (switches direction) or where
2499 * either MOSI or MISO is missing. They can also be caused by
2500 * software limitations.
2501 */
2502 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2503 || (spi->mode & SPI_3WIRE)) {
2504 unsigned flags = master->flags;
2505
2506 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2507 if (xfer->rx_buf && xfer->tx_buf)
2508 return -EINVAL;
2509 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2510 return -EINVAL;
2511 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2512 return -EINVAL;
2513 }
2514 }
2515
2516 /**
2517 * Set transfer bits_per_word and max speed as spi device default if
2518 * it is not set for this transfer.
2519 * Set transfer tx_nbits and rx_nbits as single transfer default
2520 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2521 */
2522 message->frame_length = 0;
2523 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2524 message->frame_length += xfer->len;
2525 if (!xfer->bits_per_word)
2526 xfer->bits_per_word = spi->bits_per_word;
2527
2528 if (!xfer->speed_hz)
2529 xfer->speed_hz = spi->max_speed_hz;
2530 if (!xfer->speed_hz)
2531 xfer->speed_hz = master->max_speed_hz;
2532
2533 if (master->max_speed_hz &&
2534 xfer->speed_hz > master->max_speed_hz)
2535 xfer->speed_hz = master->max_speed_hz;
2536
2537 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2538 return -EINVAL;
2539
2540 /*
2541 * SPI transfer length should be multiple of SPI word size
2542 * where SPI word size should be power-of-two multiple
2543 */
2544 if (xfer->bits_per_word <= 8)
2545 w_size = 1;
2546 else if (xfer->bits_per_word <= 16)
2547 w_size = 2;
2548 else
2549 w_size = 4;
2550
2551 /* No partial transfers accepted */
2552 if (xfer->len % w_size)
2553 return -EINVAL;
2554
2555 if (xfer->speed_hz && master->min_speed_hz &&
2556 xfer->speed_hz < master->min_speed_hz)
2557 return -EINVAL;
2558
2559 if (xfer->tx_buf && !xfer->tx_nbits)
2560 xfer->tx_nbits = SPI_NBITS_SINGLE;
2561 if (xfer->rx_buf && !xfer->rx_nbits)
2562 xfer->rx_nbits = SPI_NBITS_SINGLE;
2563 /* check transfer tx/rx_nbits:
2564 * 1. check the value matches one of single, dual and quad
2565 * 2. check tx/rx_nbits match the mode in spi_device
2566 */
2567 if (xfer->tx_buf) {
2568 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2569 xfer->tx_nbits != SPI_NBITS_DUAL &&
2570 xfer->tx_nbits != SPI_NBITS_QUAD)
2571 return -EINVAL;
2572 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2573 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2574 return -EINVAL;
2575 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2576 !(spi->mode & SPI_TX_QUAD))
2577 return -EINVAL;
2578 }
2579 /* check transfer rx_nbits */
2580 if (xfer->rx_buf) {
2581 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2582 xfer->rx_nbits != SPI_NBITS_DUAL &&
2583 xfer->rx_nbits != SPI_NBITS_QUAD)
2584 return -EINVAL;
2585 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2586 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2587 return -EINVAL;
2588 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2589 !(spi->mode & SPI_RX_QUAD))
2590 return -EINVAL;
2591 }
2592 }
2593
2594 message->status = -EINPROGRESS;
2595
2596 return 0;
2597}
2598
2599static int __spi_async(struct spi_device *spi, struct spi_message *message)
2600{
2601 struct spi_master *master = spi->master;
2602
2603 message->spi = spi;
2604
2605 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2606 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2607
2608 trace_spi_message_submit(message);
2609
2610 return master->transfer(spi, message);
2611}
2612
2613/**
2614 * spi_async - asynchronous SPI transfer
2615 * @spi: device with which data will be exchanged
2616 * @message: describes the data transfers, including completion callback
2617 * Context: any (irqs may be blocked, etc)
2618 *
2619 * This call may be used in_irq and other contexts which can't sleep,
2620 * as well as from task contexts which can sleep.
2621 *
2622 * The completion callback is invoked in a context which can't sleep.
2623 * Before that invocation, the value of message->status is undefined.
2624 * When the callback is issued, message->status holds either zero (to
2625 * indicate complete success) or a negative error code. After that
2626 * callback returns, the driver which issued the transfer request may
2627 * deallocate the associated memory; it's no longer in use by any SPI
2628 * core or controller driver code.
2629 *
2630 * Note that although all messages to a spi_device are handled in
2631 * FIFO order, messages may go to different devices in other orders.
2632 * Some device might be higher priority, or have various "hard" access
2633 * time requirements, for example.
2634 *
2635 * On detection of any fault during the transfer, processing of
2636 * the entire message is aborted, and the device is deselected.
2637 * Until returning from the associated message completion callback,
2638 * no other spi_message queued to that device will be processed.
2639 * (This rule applies equally to all the synchronous transfer calls,
2640 * which are wrappers around this core asynchronous primitive.)
2641 *
2642 * Return: zero on success, else a negative error code.
2643 */
2644int spi_async(struct spi_device *spi, struct spi_message *message)
2645{
2646 struct spi_master *master = spi->master;
2647 int ret;
2648 unsigned long flags;
2649
2650 ret = __spi_validate(spi, message);
2651 if (ret != 0)
2652 return ret;
2653
2654 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2655
2656 if (master->bus_lock_flag)
2657 ret = -EBUSY;
2658 else
2659 ret = __spi_async(spi, message);
2660
2661 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2662
2663 return ret;
2664}
2665EXPORT_SYMBOL_GPL(spi_async);
2666
2667/**
2668 * spi_async_locked - version of spi_async with exclusive bus usage
2669 * @spi: device with which data will be exchanged
2670 * @message: describes the data transfers, including completion callback
2671 * Context: any (irqs may be blocked, etc)
2672 *
2673 * This call may be used in_irq and other contexts which can't sleep,
2674 * as well as from task contexts which can sleep.
2675 *
2676 * The completion callback is invoked in a context which can't sleep.
2677 * Before that invocation, the value of message->status is undefined.
2678 * When the callback is issued, message->status holds either zero (to
2679 * indicate complete success) or a negative error code. After that
2680 * callback returns, the driver which issued the transfer request may
2681 * deallocate the associated memory; it's no longer in use by any SPI
2682 * core or controller driver code.
2683 *
2684 * Note that although all messages to a spi_device are handled in
2685 * FIFO order, messages may go to different devices in other orders.
2686 * Some device might be higher priority, or have various "hard" access
2687 * time requirements, for example.
2688 *
2689 * On detection of any fault during the transfer, processing of
2690 * the entire message is aborted, and the device is deselected.
2691 * Until returning from the associated message completion callback,
2692 * no other spi_message queued to that device will be processed.
2693 * (This rule applies equally to all the synchronous transfer calls,
2694 * which are wrappers around this core asynchronous primitive.)
2695 *
2696 * Return: zero on success, else a negative error code.
2697 */
2698int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2699{
2700 struct spi_master *master = spi->master;
2701 int ret;
2702 unsigned long flags;
2703
2704 ret = __spi_validate(spi, message);
2705 if (ret != 0)
2706 return ret;
2707
2708 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2709
2710 ret = __spi_async(spi, message);
2711
2712 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2713
2714 return ret;
2715
2716}
2717EXPORT_SYMBOL_GPL(spi_async_locked);
2718
2719
2720int spi_flash_read(struct spi_device *spi,
2721 struct spi_flash_read_message *msg)
2722
2723{
2724 struct spi_master *master = spi->master;
2725 int ret;
2726
2727 if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2728 msg->addr_nbits == SPI_NBITS_DUAL) &&
2729 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2730 return -EINVAL;
2731 if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2732 msg->addr_nbits == SPI_NBITS_QUAD) &&
2733 !(spi->mode & SPI_TX_QUAD))
2734 return -EINVAL;
2735 if (msg->data_nbits == SPI_NBITS_DUAL &&
2736 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2737 return -EINVAL;
2738 if (msg->data_nbits == SPI_NBITS_QUAD &&
2739 !(spi->mode & SPI_RX_QUAD))
2740 return -EINVAL;
2741
2742 if (master->auto_runtime_pm) {
2743 ret = pm_runtime_get_sync(master->dev.parent);
2744 if (ret < 0) {
2745 dev_err(&master->dev, "Failed to power device: %d\n",
2746 ret);
2747 return ret;
2748 }
2749 }
2750 mutex_lock(&master->bus_lock_mutex);
2751 ret = master->spi_flash_read(spi, msg);
2752 mutex_unlock(&master->bus_lock_mutex);
2753 if (master->auto_runtime_pm)
2754 pm_runtime_put(master->dev.parent);
2755
2756 return ret;
2757}
2758EXPORT_SYMBOL_GPL(spi_flash_read);
2759
2760/*-------------------------------------------------------------------------*/
2761
2762/* Utility methods for SPI master protocol drivers, layered on
2763 * top of the core. Some other utility methods are defined as
2764 * inline functions.
2765 */
2766
2767static void spi_complete(void *arg)
2768{
2769 complete(arg);
2770}
2771
2772static int __spi_sync(struct spi_device *spi, struct spi_message *message,
2773 int bus_locked)
2774{
2775 DECLARE_COMPLETION_ONSTACK(done);
2776 int status;
2777 struct spi_master *master = spi->master;
2778 unsigned long flags;
2779
2780 status = __spi_validate(spi, message);
2781 if (status != 0)
2782 return status;
2783
2784 message->complete = spi_complete;
2785 message->context = &done;
2786 message->spi = spi;
2787
2788 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2789 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2790
2791 if (!bus_locked)
2792 mutex_lock(&master->bus_lock_mutex);
2793
2794 /* If we're not using the legacy transfer method then we will
2795 * try to transfer in the calling context so special case.
2796 * This code would be less tricky if we could remove the
2797 * support for driver implemented message queues.
2798 */
2799 if (master->transfer == spi_queued_transfer) {
2800 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2801
2802 trace_spi_message_submit(message);
2803
2804 status = __spi_queued_transfer(spi, message, false);
2805
2806 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2807 } else {
2808 status = spi_async_locked(spi, message);
2809 }
2810
2811 if (!bus_locked)
2812 mutex_unlock(&master->bus_lock_mutex);
2813
2814 if (status == 0) {
2815 /* Push out the messages in the calling context if we
2816 * can.
2817 */
2818 if (master->transfer == spi_queued_transfer) {
2819 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2820 spi_sync_immediate);
2821 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
2822 spi_sync_immediate);
2823 __spi_pump_messages(master, false, bus_locked);
2824 }
2825
2826 wait_for_completion(&done);
2827 status = message->status;
2828 }
2829 message->context = NULL;
2830 return status;
2831}
2832
2833/**
2834 * spi_sync - blocking/synchronous SPI data transfers
2835 * @spi: device with which data will be exchanged
2836 * @message: describes the data transfers
2837 * Context: can sleep
2838 *
2839 * This call may only be used from a context that may sleep. The sleep
2840 * is non-interruptible, and has no timeout. Low-overhead controller
2841 * drivers may DMA directly into and out of the message buffers.
2842 *
2843 * Note that the SPI device's chip select is active during the message,
2844 * and then is normally disabled between messages. Drivers for some
2845 * frequently-used devices may want to minimize costs of selecting a chip,
2846 * by leaving it selected in anticipation that the next message will go
2847 * to the same chip. (That may increase power usage.)
2848 *
2849 * Also, the caller is guaranteeing that the memory associated with the
2850 * message will not be freed before this call returns.
2851 *
2852 * Return: zero on success, else a negative error code.
2853 */
2854int spi_sync(struct spi_device *spi, struct spi_message *message)
2855{
2856 return __spi_sync(spi, message, spi->master->bus_lock_flag);
2857}
2858EXPORT_SYMBOL_GPL(spi_sync);
2859
2860/**
2861 * spi_sync_locked - version of spi_sync with exclusive bus usage
2862 * @spi: device with which data will be exchanged
2863 * @message: describes the data transfers
2864 * Context: can sleep
2865 *
2866 * This call may only be used from a context that may sleep. The sleep
2867 * is non-interruptible, and has no timeout. Low-overhead controller
2868 * drivers may DMA directly into and out of the message buffers.
2869 *
2870 * This call should be used by drivers that require exclusive access to the
2871 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
2872 * be released by a spi_bus_unlock call when the exclusive access is over.
2873 *
2874 * Return: zero on success, else a negative error code.
2875 */
2876int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2877{
2878 return __spi_sync(spi, message, 1);
2879}
2880EXPORT_SYMBOL_GPL(spi_sync_locked);
2881
2882/**
2883 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2884 * @master: SPI bus master that should be locked for exclusive bus access
2885 * Context: can sleep
2886 *
2887 * This call may only be used from a context that may sleep. The sleep
2888 * is non-interruptible, and has no timeout.
2889 *
2890 * This call should be used by drivers that require exclusive access to the
2891 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2892 * exclusive access is over. Data transfer must be done by spi_sync_locked
2893 * and spi_async_locked calls when the SPI bus lock is held.
2894 *
2895 * Return: always zero.
2896 */
2897int spi_bus_lock(struct spi_master *master)
2898{
2899 unsigned long flags;
2900
2901 mutex_lock(&master->bus_lock_mutex);
2902
2903 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2904 master->bus_lock_flag = 1;
2905 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2906
2907 /* mutex remains locked until spi_bus_unlock is called */
2908
2909 return 0;
2910}
2911EXPORT_SYMBOL_GPL(spi_bus_lock);
2912
2913/**
2914 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2915 * @master: SPI bus master that was locked for exclusive bus access
2916 * Context: can sleep
2917 *
2918 * This call may only be used from a context that may sleep. The sleep
2919 * is non-interruptible, and has no timeout.
2920 *
2921 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2922 * call.
2923 *
2924 * Return: always zero.
2925 */
2926int spi_bus_unlock(struct spi_master *master)
2927{
2928 master->bus_lock_flag = 0;
2929
2930 mutex_unlock(&master->bus_lock_mutex);
2931
2932 return 0;
2933}
2934EXPORT_SYMBOL_GPL(spi_bus_unlock);
2935
2936/* portable code must never pass more than 32 bytes */
2937#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
2938
2939static u8 *buf;
2940
2941/**
2942 * spi_write_then_read - SPI synchronous write followed by read
2943 * @spi: device with which data will be exchanged
2944 * @txbuf: data to be written (need not be dma-safe)
2945 * @n_tx: size of txbuf, in bytes
2946 * @rxbuf: buffer into which data will be read (need not be dma-safe)
2947 * @n_rx: size of rxbuf, in bytes
2948 * Context: can sleep
2949 *
2950 * This performs a half duplex MicroWire style transaction with the
2951 * device, sending txbuf and then reading rxbuf. The return value
2952 * is zero for success, else a negative errno status code.
2953 * This call may only be used from a context that may sleep.
2954 *
2955 * Parameters to this routine are always copied using a small buffer;
2956 * portable code should never use this for more than 32 bytes.
2957 * Performance-sensitive or bulk transfer code should instead use
2958 * spi_{async,sync}() calls with dma-safe buffers.
2959 *
2960 * Return: zero on success, else a negative error code.
2961 */
2962int spi_write_then_read(struct spi_device *spi,
2963 const void *txbuf, unsigned n_tx,
2964 void *rxbuf, unsigned n_rx)
2965{
2966 static DEFINE_MUTEX(lock);
2967
2968 int status;
2969 struct spi_message message;
2970 struct spi_transfer x[2];
2971 u8 *local_buf;
2972
2973 /* Use preallocated DMA-safe buffer if we can. We can't avoid
2974 * copying here, (as a pure convenience thing), but we can
2975 * keep heap costs out of the hot path unless someone else is
2976 * using the pre-allocated buffer or the transfer is too large.
2977 */
2978 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
2979 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
2980 GFP_KERNEL | GFP_DMA);
2981 if (!local_buf)
2982 return -ENOMEM;
2983 } else {
2984 local_buf = buf;
2985 }
2986
2987 spi_message_init(&message);
2988 memset(x, 0, sizeof(x));
2989 if (n_tx) {
2990 x[0].len = n_tx;
2991 spi_message_add_tail(&x[0], &message);
2992 }
2993 if (n_rx) {
2994 x[1].len = n_rx;
2995 spi_message_add_tail(&x[1], &message);
2996 }
2997
2998 memcpy(local_buf, txbuf, n_tx);
2999 x[0].tx_buf = local_buf;
3000 x[1].rx_buf = local_buf + n_tx;
3001
3002 /* do the i/o */
3003 status = spi_sync(spi, &message);
3004 if (status == 0)
3005 memcpy(rxbuf, x[1].rx_buf, n_rx);
3006
3007 if (x[0].tx_buf == buf)
3008 mutex_unlock(&lock);
3009 else
3010 kfree(local_buf);
3011
3012 return status;
3013}
3014EXPORT_SYMBOL_GPL(spi_write_then_read);
3015
3016/*-------------------------------------------------------------------------*/
3017
3018#if IS_ENABLED(CONFIG_OF_DYNAMIC)
3019static int __spi_of_device_match(struct device *dev, void *data)
3020{
3021 return dev->of_node == data;
3022}
3023
3024/* must call put_device() when done with returned spi_device device */
3025static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3026{
3027 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3028 __spi_of_device_match);
3029 return dev ? to_spi_device(dev) : NULL;
3030}
3031
3032static int __spi_of_master_match(struct device *dev, const void *data)
3033{
3034 return dev->of_node == data;
3035}
3036
3037/* the spi masters are not using spi_bus, so we find it with another way */
3038static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3039{
3040 struct device *dev;
3041
3042 dev = class_find_device(&spi_master_class, NULL, node,
3043 __spi_of_master_match);
3044 if (!dev)
3045 return NULL;
3046
3047 /* reference got in class_find_device */
3048 return container_of(dev, struct spi_master, dev);
3049}
3050
3051static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3052 void *arg)
3053{
3054 struct of_reconfig_data *rd = arg;
3055 struct spi_master *master;
3056 struct spi_device *spi;
3057
3058 switch (of_reconfig_get_state_change(action, arg)) {
3059 case OF_RECONFIG_CHANGE_ADD:
3060 master = of_find_spi_master_by_node(rd->dn->parent);
3061 if (master == NULL)
3062 return NOTIFY_OK; /* not for us */
3063
3064 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3065 put_device(&master->dev);
3066 return NOTIFY_OK;
3067 }
3068
3069 spi = of_register_spi_device(master, rd->dn);
3070 put_device(&master->dev);
3071
3072 if (IS_ERR(spi)) {
3073 pr_err("%s: failed to create for '%s'\n",
3074 __func__, rd->dn->full_name);
3075 return notifier_from_errno(PTR_ERR(spi));
3076 }
3077 break;
3078
3079 case OF_RECONFIG_CHANGE_REMOVE:
3080 /* already depopulated? */
3081 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3082 return NOTIFY_OK;
3083
3084 /* find our device by node */
3085 spi = of_find_spi_device_by_node(rd->dn);
3086 if (spi == NULL)
3087 return NOTIFY_OK; /* no? not meant for us */
3088
3089 /* unregister takes one ref away */
3090 spi_unregister_device(spi);
3091
3092 /* and put the reference of the find */
3093 put_device(&spi->dev);
3094 break;
3095 }
3096
3097 return NOTIFY_OK;
3098}
3099
3100static struct notifier_block spi_of_notifier = {
3101 .notifier_call = of_spi_notify,
3102};
3103#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3104extern struct notifier_block spi_of_notifier;
3105#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3106
3107static int __init spi_init(void)
3108{
3109 int status;
3110
3111 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
3112 if (!buf) {
3113 status = -ENOMEM;
3114 goto err0;
3115 }
3116
3117 status = bus_register(&spi_bus_type);
3118 if (status < 0)
3119 goto err1;
3120
3121 status = class_register(&spi_master_class);
3122 if (status < 0)
3123 goto err2;
3124
3125 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
3126 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3127
3128 return 0;
3129
3130err2:
3131 bus_unregister(&spi_bus_type);
3132err1:
3133 kfree(buf);
3134 buf = NULL;
3135err0:
3136 return status;
3137}
3138
3139/* board_info is normally registered in arch_initcall(),
3140 * but even essential drivers wait till later
3141 *
3142 * REVISIT only boardinfo really needs static linking. the rest (device and
3143 * driver registration) _could_ be dynamically linked (modular) ... costs
3144 * include needing to have boardinfo data structures be much more public.
3145 */
3146postcore_initcall(spi_init);
3147
1/*
2 * SPI init/core code
3 *
4 * Copyright (C) 2005 David Brownell
5 * Copyright (C) 2008 Secret Lab Technologies Ltd.
6 *
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.
11 *
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.
16 */
17
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>
41
42#define CREATE_TRACE_POINTS
43#include <trace/events/spi.h>
44
45static void spidev_release(struct device *dev)
46{
47 struct spi_device *spi = to_spi_device(dev);
48
49 /* spi masters may cleanup for released devices */
50 if (spi->master->cleanup)
51 spi->master->cleanup(spi);
52
53 spi_master_put(spi->master);
54 kfree(spi);
55}
56
57static ssize_t
58modalias_show(struct device *dev, struct device_attribute *a, char *buf)
59{
60 const struct spi_device *spi = to_spi_device(dev);
61 int len;
62
63 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
64 if (len != -ENODEV)
65 return len;
66
67 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
68}
69static DEVICE_ATTR_RO(modalias);
70
71#define SPI_STATISTICS_ATTRS(field, file) \
72static ssize_t spi_master_##field##_show(struct device *dev, \
73 struct device_attribute *attr, \
74 char *buf) \
75{ \
76 struct spi_master *master = container_of(dev, \
77 struct spi_master, dev); \
78 return spi_statistics_##field##_show(&master->statistics, buf); \
79} \
80static struct device_attribute dev_attr_spi_master_##field = { \
81 .attr = { .name = file, .mode = S_IRUGO }, \
82 .show = spi_master_##field##_show, \
83}; \
84static ssize_t spi_device_##field##_show(struct device *dev, \
85 struct device_attribute *attr, \
86 char *buf) \
87{ \
88 struct spi_device *spi = to_spi_device(dev); \
89 return spi_statistics_##field##_show(&spi->statistics, buf); \
90} \
91static struct device_attribute dev_attr_spi_device_##field = { \
92 .attr = { .name = file, .mode = S_IRUGO }, \
93 .show = spi_device_##field##_show, \
94}
95
96#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
97static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
98 char *buf) \
99{ \
100 unsigned long flags; \
101 ssize_t len; \
102 spin_lock_irqsave(&stat->lock, flags); \
103 len = sprintf(buf, format_string, stat->field); \
104 spin_unlock_irqrestore(&stat->lock, flags); \
105 return len; \
106} \
107SPI_STATISTICS_ATTRS(name, file)
108
109#define SPI_STATISTICS_SHOW(field, format_string) \
110 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
111 field, format_string)
112
113SPI_STATISTICS_SHOW(messages, "%lu");
114SPI_STATISTICS_SHOW(transfers, "%lu");
115SPI_STATISTICS_SHOW(errors, "%lu");
116SPI_STATISTICS_SHOW(timedout, "%lu");
117
118SPI_STATISTICS_SHOW(spi_sync, "%lu");
119SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
120SPI_STATISTICS_SHOW(spi_async, "%lu");
121
122SPI_STATISTICS_SHOW(bytes, "%llu");
123SPI_STATISTICS_SHOW(bytes_rx, "%llu");
124SPI_STATISTICS_SHOW(bytes_tx, "%llu");
125
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")
130SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
131SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
132SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
133SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
134SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
135SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
136SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
137SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
138SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
139SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
140SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
141SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
142SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
143SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
144SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
145SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
146SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
147
148SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
149
150static struct attribute *spi_dev_attrs[] = {
151 &dev_attr_modalias.attr,
152 NULL,
153};
154
155static const struct attribute_group spi_dev_group = {
156 .attrs = spi_dev_attrs,
157};
158
159static 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,
188 NULL,
189};
190
191static const struct attribute_group spi_device_statistics_group = {
192 .name = "statistics",
193 .attrs = spi_device_statistics_attrs,
194};
195
196static const struct attribute_group *spi_dev_groups[] = {
197 &spi_dev_group,
198 &spi_device_statistics_group,
199 NULL,
200};
201
202static 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,
231 NULL,
232};
233
234static const struct attribute_group spi_master_statistics_group = {
235 .name = "statistics",
236 .attrs = spi_master_statistics_attrs,
237};
238
239static const struct attribute_group *spi_master_groups[] = {
240 &spi_master_statistics_group,
241 NULL,
242};
243
244void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
245 struct spi_transfer *xfer,
246 struct spi_master *master)
247{
248 unsigned long flags;
249 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
250
251 if (l2len < 0)
252 l2len = 0;
253
254 spin_lock_irqsave(&stats->lock, flags);
255
256 stats->transfers++;
257 stats->transfer_bytes_histo[l2len]++;
258
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;
266
267 spin_unlock_irqrestore(&stats->lock, flags);
268}
269EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
270
271/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
272 * and the sysfs version makes coldplug work too.
273 */
274
275static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
276 const struct spi_device *sdev)
277{
278 while (id->name[0]) {
279 if (!strcmp(sdev->modalias, id->name))
280 return id;
281 id++;
282 }
283 return NULL;
284}
285
286const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
287{
288 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
289
290 return spi_match_id(sdrv->id_table, sdev);
291}
292EXPORT_SYMBOL_GPL(spi_get_device_id);
293
294static int spi_match_device(struct device *dev, struct device_driver *drv)
295{
296 const struct spi_device *spi = to_spi_device(dev);
297 const struct spi_driver *sdrv = to_spi_driver(drv);
298
299 /* Attempt an OF style match */
300 if (of_driver_match_device(dev, drv))
301 return 1;
302
303 /* Then try ACPI */
304 if (acpi_driver_match_device(dev, drv))
305 return 1;
306
307 if (sdrv->id_table)
308 return !!spi_match_id(sdrv->id_table, spi);
309
310 return strcmp(spi->modalias, drv->name) == 0;
311}
312
313static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
314{
315 const struct spi_device *spi = to_spi_device(dev);
316 int rc;
317
318 rc = acpi_device_uevent_modalias(dev, env);
319 if (rc != -ENODEV)
320 return rc;
321
322 add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
323 return 0;
324}
325
326struct bus_type spi_bus_type = {
327 .name = "spi",
328 .dev_groups = spi_dev_groups,
329 .match = spi_match_device,
330 .uevent = spi_uevent,
331};
332EXPORT_SYMBOL_GPL(spi_bus_type);
333
334
335static int spi_drv_probe(struct device *dev)
336{
337 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
338 struct spi_device *spi = to_spi_device(dev);
339 int ret;
340
341 ret = of_clk_set_defaults(dev->of_node, false);
342 if (ret)
343 return ret;
344
345 if (dev->of_node) {
346 spi->irq = of_irq_get(dev->of_node, 0);
347 if (spi->irq == -EPROBE_DEFER)
348 return -EPROBE_DEFER;
349 if (spi->irq < 0)
350 spi->irq = 0;
351 }
352
353 ret = dev_pm_domain_attach(dev, true);
354 if (ret != -EPROBE_DEFER) {
355 ret = sdrv->probe(spi);
356 if (ret)
357 dev_pm_domain_detach(dev, true);
358 }
359
360 return ret;
361}
362
363static int spi_drv_remove(struct device *dev)
364{
365 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
366 int ret;
367
368 ret = sdrv->remove(to_spi_device(dev));
369 dev_pm_domain_detach(dev, true);
370
371 return ret;
372}
373
374static void spi_drv_shutdown(struct device *dev)
375{
376 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
377
378 sdrv->shutdown(to_spi_device(dev));
379}
380
381/**
382 * __spi_register_driver - register a SPI driver
383 * @owner: owner module of the driver to register
384 * @sdrv: the driver to register
385 * Context: can sleep
386 *
387 * Return: zero on success, else a negative error code.
388 */
389int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
390{
391 sdrv->driver.owner = owner;
392 sdrv->driver.bus = &spi_bus_type;
393 if (sdrv->probe)
394 sdrv->driver.probe = spi_drv_probe;
395 if (sdrv->remove)
396 sdrv->driver.remove = spi_drv_remove;
397 if (sdrv->shutdown)
398 sdrv->driver.shutdown = spi_drv_shutdown;
399 return driver_register(&sdrv->driver);
400}
401EXPORT_SYMBOL_GPL(__spi_register_driver);
402
403/*-------------------------------------------------------------------------*/
404
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.
409 */
410
411struct boardinfo {
412 struct list_head list;
413 struct spi_board_info board_info;
414};
415
416static LIST_HEAD(board_list);
417static LIST_HEAD(spi_master_list);
418
419/*
420 * Used to protect add/del opertion for board_info list and
421 * spi_master list, and their matching process
422 */
423static DEFINE_MUTEX(board_lock);
424
425/**
426 * spi_alloc_device - Allocate a new SPI device
427 * @master: Controller to which device is connected
428 * Context: can sleep
429 *
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.
434 *
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.
439 *
440 * Return: a pointer to the new device, or NULL.
441 */
442struct spi_device *spi_alloc_device(struct spi_master *master)
443{
444 struct spi_device *spi;
445
446 if (!spi_master_get(master))
447 return NULL;
448
449 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
450 if (!spi) {
451 spi_master_put(master);
452 return NULL;
453 }
454
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;
460
461 spin_lock_init(&spi->statistics.lock);
462
463 device_initialize(&spi->dev);
464 return spi;
465}
466EXPORT_SYMBOL_GPL(spi_alloc_device);
467
468static void spi_dev_set_name(struct spi_device *spi)
469{
470 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
471
472 if (adev) {
473 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
474 return;
475 }
476
477 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
478 spi->chip_select);
479}
480
481static int spi_dev_check(struct device *dev, void *data)
482{
483 struct spi_device *spi = to_spi_device(dev);
484 struct spi_device *new_spi = data;
485
486 if (spi->master == new_spi->master &&
487 spi->chip_select == new_spi->chip_select)
488 return -EBUSY;
489 return 0;
490}
491
492/**
493 * spi_add_device - Add spi_device allocated with spi_alloc_device
494 * @spi: spi_device to register
495 *
496 * Companion function to spi_alloc_device. Devices allocated with
497 * spi_alloc_device can be added onto the spi bus with this function.
498 *
499 * Return: 0 on success; negative errno on failure
500 */
501int spi_add_device(struct spi_device *spi)
502{
503 static DEFINE_MUTEX(spi_add_lock);
504 struct spi_master *master = spi->master;
505 struct device *dev = master->dev.parent;
506 int status;
507
508 /* Chipselects are numbered 0..max; validate. */
509 if (spi->chip_select >= master->num_chipselect) {
510 dev_err(dev, "cs%d >= max %d\n",
511 spi->chip_select,
512 master->num_chipselect);
513 return -EINVAL;
514 }
515
516 /* Set the bus ID string */
517 spi_dev_set_name(spi);
518
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.
522 */
523 mutex_lock(&spi_add_lock);
524
525 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
526 if (status) {
527 dev_err(dev, "chipselect %d already in use\n",
528 spi->chip_select);
529 goto done;
530 }
531
532 if (master->cs_gpios)
533 spi->cs_gpio = master->cs_gpios[spi->chip_select];
534
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...
538 */
539 status = spi_setup(spi);
540 if (status < 0) {
541 dev_err(dev, "can't setup %s, status %d\n",
542 dev_name(&spi->dev), status);
543 goto done;
544 }
545
546 /* Device may be bound to an active driver when this returns */
547 status = device_add(&spi->dev);
548 if (status < 0)
549 dev_err(dev, "can't add %s, status %d\n",
550 dev_name(&spi->dev), status);
551 else
552 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
553
554done:
555 mutex_unlock(&spi_add_lock);
556 return status;
557}
558EXPORT_SYMBOL_GPL(spi_add_device);
559
560/**
561 * spi_new_device - instantiate one new SPI device
562 * @master: Controller to which device is connected
563 * @chip: Describes the SPI device
564 * Context: can sleep
565 *
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).
571 *
572 * Return: the new device, or NULL.
573 */
574struct spi_device *spi_new_device(struct spi_master *master,
575 struct spi_board_info *chip)
576{
577 struct spi_device *proxy;
578 int status;
579
580 /* NOTE: caller did any chip->bus_num checks necessary.
581 *
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).
585 */
586
587 proxy = spi_alloc_device(master);
588 if (!proxy)
589 return NULL;
590
591 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
592
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;
601
602 status = spi_add_device(proxy);
603 if (status < 0) {
604 spi_dev_put(proxy);
605 return NULL;
606 }
607
608 return proxy;
609}
610EXPORT_SYMBOL_GPL(spi_new_device);
611
612/**
613 * spi_unregister_device - unregister a single SPI device
614 * @spi: spi_device to unregister
615 *
616 * Start making the passed SPI device vanish. Normally this would be handled
617 * by spi_unregister_master().
618 */
619void spi_unregister_device(struct spi_device *spi)
620{
621 if (!spi)
622 return;
623
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);
629}
630EXPORT_SYMBOL_GPL(spi_unregister_device);
631
632static void spi_match_master_to_boardinfo(struct spi_master *master,
633 struct spi_board_info *bi)
634{
635 struct spi_device *dev;
636
637 if (master->bus_num != bi->bus_num)
638 return;
639
640 dev = spi_new_device(master, bi);
641 if (!dev)
642 dev_err(master->dev.parent, "can't create new device for %s\n",
643 bi->modalias);
644}
645
646/**
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
650 * Context: can sleep
651 *
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.
657 *
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.
661 *
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.
664 *
665 * Return: zero on success, else a negative error code.
666 */
667int spi_register_board_info(struct spi_board_info const *info, unsigned n)
668{
669 struct boardinfo *bi;
670 int i;
671
672 if (!n)
673 return -EINVAL;
674
675 bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
676 if (!bi)
677 return -ENOMEM;
678
679 for (i = 0; i < n; i++, bi++, info++) {
680 struct spi_master *master;
681
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);
688 }
689
690 return 0;
691}
692
693/*-------------------------------------------------------------------------*/
694
695static void spi_set_cs(struct spi_device *spi, bool enable)
696{
697 if (spi->mode & SPI_CS_HIGH)
698 enable = !enable;
699
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) &&
704 spi->master->set_cs)
705 spi->master->set_cs(spi, !enable);
706 } else if (spi->master->set_cs) {
707 spi->master->set_cs(spi, !enable);
708 }
709}
710
711#ifdef CONFIG_HAS_DMA
712static 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)
715{
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)));
722#else
723 const bool kmap_buf = false;
724#endif
725 int desc_len;
726 int sgs;
727 struct page *vm_page;
728 struct scatterlist *sg;
729 void *sg_buf;
730 size_t min;
731 int i, ret;
732
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);
739 } else {
740 return -EINVAL;
741 }
742
743 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
744 if (ret != 0)
745 return ret;
746
747 sg = &sgt->sgl[0];
748 for (i = 0; i < sgs; i++) {
749
750 if (vmalloced_buf || kmap_buf) {
751 min = min_t(size_t,
752 len, desc_len - offset_in_page(buf));
753 if (vmalloced_buf)
754 vm_page = vmalloc_to_page(buf);
755 else
756 vm_page = kmap_to_page(buf);
757 if (!vm_page) {
758 sg_free_table(sgt);
759 return -ENOMEM;
760 }
761 sg_set_page(sg, vm_page,
762 min, offset_in_page(buf));
763 } else {
764 min = min_t(size_t, len, desc_len);
765 sg_buf = buf;
766 sg_set_buf(sg, sg_buf, min);
767 }
768
769 buf += min;
770 len -= min;
771 sg = sg_next(sg);
772 }
773
774 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
775 if (!ret)
776 ret = -ENOMEM;
777 if (ret < 0) {
778 sg_free_table(sgt);
779 return ret;
780 }
781
782 sgt->nents = ret;
783
784 return 0;
785}
786
787static void spi_unmap_buf(struct spi_master *master, struct device *dev,
788 struct sg_table *sgt, enum dma_data_direction dir)
789{
790 if (sgt->orig_nents) {
791 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
792 sg_free_table(sgt);
793 }
794}
795
796static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
797{
798 struct device *tx_dev, *rx_dev;
799 struct spi_transfer *xfer;
800 int ret;
801
802 if (!master->can_dma)
803 return 0;
804
805 if (master->dma_tx)
806 tx_dev = master->dma_tx->device->dev;
807 else
808 tx_dev = &master->dev;
809
810 if (master->dma_rx)
811 rx_dev = master->dma_rx->device->dev;
812 else
813 rx_dev = &master->dev;
814
815 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
816 if (!master->can_dma(master, msg->spi, xfer))
817 continue;
818
819 if (xfer->tx_buf != NULL) {
820 ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
821 (void *)xfer->tx_buf, xfer->len,
822 DMA_TO_DEVICE);
823 if (ret != 0)
824 return ret;
825 }
826
827 if (xfer->rx_buf != NULL) {
828 ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
829 xfer->rx_buf, xfer->len,
830 DMA_FROM_DEVICE);
831 if (ret != 0) {
832 spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
833 DMA_TO_DEVICE);
834 return ret;
835 }
836 }
837 }
838
839 master->cur_msg_mapped = true;
840
841 return 0;
842}
843
844static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
845{
846 struct spi_transfer *xfer;
847 struct device *tx_dev, *rx_dev;
848
849 if (!master->cur_msg_mapped || !master->can_dma)
850 return 0;
851
852 if (master->dma_tx)
853 tx_dev = master->dma_tx->device->dev;
854 else
855 tx_dev = &master->dev;
856
857 if (master->dma_rx)
858 rx_dev = master->dma_rx->device->dev;
859 else
860 rx_dev = &master->dev;
861
862 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
863 if (!master->can_dma(master, msg->spi, xfer))
864 continue;
865
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);
868 }
869
870 return 0;
871}
872#else /* !CONFIG_HAS_DMA */
873static 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)
877{
878 return -EINVAL;
879}
880
881static inline void spi_unmap_buf(struct spi_master *master,
882 struct device *dev, struct sg_table *sgt,
883 enum dma_data_direction dir)
884{
885}
886
887static inline int __spi_map_msg(struct spi_master *master,
888 struct spi_message *msg)
889{
890 return 0;
891}
892
893static inline int __spi_unmap_msg(struct spi_master *master,
894 struct spi_message *msg)
895{
896 return 0;
897}
898#endif /* !CONFIG_HAS_DMA */
899
900static inline int spi_unmap_msg(struct spi_master *master,
901 struct spi_message *msg)
902{
903 struct spi_transfer *xfer;
904
905 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
906 /*
907 * Restore the original value of tx_buf or rx_buf if they are
908 * NULL.
909 */
910 if (xfer->tx_buf == master->dummy_tx)
911 xfer->tx_buf = NULL;
912 if (xfer->rx_buf == master->dummy_rx)
913 xfer->rx_buf = NULL;
914 }
915
916 return __spi_unmap_msg(master, msg);
917}
918
919static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
920{
921 struct spi_transfer *xfer;
922 void *tmp;
923 unsigned int max_tx, max_rx;
924
925 if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
926 max_tx = 0;
927 max_rx = 0;
928
929 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
930 if ((master->flags & SPI_MASTER_MUST_TX) &&
931 !xfer->tx_buf)
932 max_tx = max(xfer->len, max_tx);
933 if ((master->flags & SPI_MASTER_MUST_RX) &&
934 !xfer->rx_buf)
935 max_rx = max(xfer->len, max_rx);
936 }
937
938 if (max_tx) {
939 tmp = krealloc(master->dummy_tx, max_tx,
940 GFP_KERNEL | GFP_DMA);
941 if (!tmp)
942 return -ENOMEM;
943 master->dummy_tx = tmp;
944 memset(tmp, 0, max_tx);
945 }
946
947 if (max_rx) {
948 tmp = krealloc(master->dummy_rx, max_rx,
949 GFP_KERNEL | GFP_DMA);
950 if (!tmp)
951 return -ENOMEM;
952 master->dummy_rx = tmp;
953 }
954
955 if (max_tx || max_rx) {
956 list_for_each_entry(xfer, &msg->transfers,
957 transfer_list) {
958 if (!xfer->tx_buf)
959 xfer->tx_buf = master->dummy_tx;
960 if (!xfer->rx_buf)
961 xfer->rx_buf = master->dummy_rx;
962 }
963 }
964 }
965
966 return __spi_map_msg(master, msg);
967}
968
969/*
970 * spi_transfer_one_message - Default implementation of transfer_one_message()
971 *
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.
975 */
976static int spi_transfer_one_message(struct spi_master *master,
977 struct spi_message *msg)
978{
979 struct spi_transfer *xfer;
980 bool keep_cs = false;
981 int ret = 0;
982 unsigned long long ms = 1;
983 struct spi_statistics *statm = &master->statistics;
984 struct spi_statistics *stats = &msg->spi->statistics;
985
986 spi_set_cs(msg->spi, true);
987
988 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
989 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
990
991 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
992 trace_spi_transfer_start(msg, xfer);
993
994 spi_statistics_add_transfer_stats(statm, xfer, master);
995 spi_statistics_add_transfer_stats(stats, xfer, master);
996
997 if (xfer->tx_buf || xfer->rx_buf) {
998 reinit_completion(&master->xfer_completion);
999
1000 ret = master->transfer_one(master, msg->spi, xfer);
1001 if (ret < 0) {
1002 SPI_STATISTICS_INCREMENT_FIELD(statm,
1003 errors);
1004 SPI_STATISTICS_INCREMENT_FIELD(stats,
1005 errors);
1006 dev_err(&msg->spi->dev,
1007 "SPI transfer failed: %d\n", ret);
1008 goto out;
1009 }
1010
1011 if (ret > 0) {
1012 ret = 0;
1013 ms = 8LL * 1000LL * xfer->len;
1014 do_div(ms, xfer->speed_hz);
1015 ms += ms + 100; /* some tolerance */
1016
1017 if (ms > UINT_MAX)
1018 ms = UINT_MAX;
1019
1020 ms = wait_for_completion_timeout(&master->xfer_completion,
1021 msecs_to_jiffies(ms));
1022 }
1023
1024 if (ms == 0) {
1025 SPI_STATISTICS_INCREMENT_FIELD(statm,
1026 timedout);
1027 SPI_STATISTICS_INCREMENT_FIELD(stats,
1028 timedout);
1029 dev_err(&msg->spi->dev,
1030 "SPI transfer timed out\n");
1031 msg->status = -ETIMEDOUT;
1032 }
1033 } else {
1034 if (xfer->len)
1035 dev_err(&msg->spi->dev,
1036 "Bufferless transfer has length %u\n",
1037 xfer->len);
1038 }
1039
1040 trace_spi_transfer_stop(msg, xfer);
1041
1042 if (msg->status != -EINPROGRESS)
1043 goto out;
1044
1045 if (xfer->delay_usecs) {
1046 u16 us = xfer->delay_usecs;
1047
1048 if (us <= 10)
1049 udelay(us);
1050 else
1051 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1052 }
1053
1054 if (xfer->cs_change) {
1055 if (list_is_last(&xfer->transfer_list,
1056 &msg->transfers)) {
1057 keep_cs = true;
1058 } else {
1059 spi_set_cs(msg->spi, false);
1060 udelay(10);
1061 spi_set_cs(msg->spi, true);
1062 }
1063 }
1064
1065 msg->actual_length += xfer->len;
1066 }
1067
1068out:
1069 if (ret != 0 || !keep_cs)
1070 spi_set_cs(msg->spi, false);
1071
1072 if (msg->status == -EINPROGRESS)
1073 msg->status = ret;
1074
1075 if (msg->status && master->handle_err)
1076 master->handle_err(master, msg);
1077
1078 spi_res_release(master, msg);
1079
1080 spi_finalize_current_message(master);
1081
1082 return ret;
1083}
1084
1085/**
1086 * spi_finalize_current_transfer - report completion of a transfer
1087 * @master: the master reporting completion
1088 *
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.
1092 */
1093void spi_finalize_current_transfer(struct spi_master *master)
1094{
1095 complete(&master->xfer_completion);
1096}
1097EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1098
1099/**
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
1103 *
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.
1107 *
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.
1111 */
1112static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
1113{
1114 unsigned long flags;
1115 bool was_busy = false;
1116 int ret;
1117
1118 /* Lock queue */
1119 spin_lock_irqsave(&master->queue_lock, flags);
1120
1121 /* Make sure we are not already running a message */
1122 if (master->cur_msg) {
1123 spin_unlock_irqrestore(&master->queue_lock, flags);
1124 return;
1125 }
1126
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);
1131 return;
1132 }
1133
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);
1138 return;
1139 }
1140
1141 /* Only do teardown in the thread */
1142 if (!in_kthread) {
1143 kthread_queue_work(&master->kworker,
1144 &master->pump_messages);
1145 spin_unlock_irqrestore(&master->queue_lock, flags);
1146 return;
1147 }
1148
1149 master->busy = false;
1150 master->idling = true;
1151 spin_unlock_irqrestore(&master->queue_lock, flags);
1152
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);
1164 }
1165 trace_spi_master_idle(master);
1166
1167 spin_lock_irqsave(&master->queue_lock, flags);
1168 master->idling = false;
1169 spin_unlock_irqrestore(&master->queue_lock, flags);
1170 return;
1171 }
1172
1173 /* Extract head of queue */
1174 master->cur_msg =
1175 list_first_entry(&master->queue, struct spi_message, queue);
1176
1177 list_del_init(&master->cur_msg->queue);
1178 if (master->busy)
1179 was_busy = true;
1180 else
1181 master->busy = true;
1182 spin_unlock_irqrestore(&master->queue_lock, flags);
1183
1184 mutex_lock(&master->io_mutex);
1185
1186 if (!was_busy && master->auto_runtime_pm) {
1187 ret = pm_runtime_get_sync(master->dev.parent);
1188 if (ret < 0) {
1189 dev_err(&master->dev, "Failed to power device: %d\n",
1190 ret);
1191 mutex_unlock(&master->io_mutex);
1192 return;
1193 }
1194 }
1195
1196 if (!was_busy)
1197 trace_spi_master_busy(master);
1198
1199 if (!was_busy && master->prepare_transfer_hardware) {
1200 ret = master->prepare_transfer_hardware(master);
1201 if (ret) {
1202 dev_err(&master->dev,
1203 "failed to prepare transfer hardware\n");
1204
1205 if (master->auto_runtime_pm)
1206 pm_runtime_put(master->dev.parent);
1207 mutex_unlock(&master->io_mutex);
1208 return;
1209 }
1210 }
1211
1212 trace_spi_message_start(master->cur_msg);
1213
1214 if (master->prepare_message) {
1215 ret = master->prepare_message(master, master->cur_msg);
1216 if (ret) {
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);
1221 goto out;
1222 }
1223 master->cur_msg_prepared = true;
1224 }
1225
1226 ret = spi_map_msg(master, master->cur_msg);
1227 if (ret) {
1228 master->cur_msg->status = ret;
1229 spi_finalize_current_message(master);
1230 goto out;
1231 }
1232
1233 ret = master->transfer_one_message(master, master->cur_msg);
1234 if (ret) {
1235 dev_err(&master->dev,
1236 "failed to transfer one message from queue\n");
1237 goto out;
1238 }
1239
1240out:
1241 mutex_unlock(&master->io_mutex);
1242
1243 /* Prod the scheduler in case transfer_one() was busy waiting */
1244 if (!ret)
1245 cond_resched();
1246}
1247
1248/**
1249 * spi_pump_messages - kthread work function which processes spi message queue
1250 * @work: pointer to kthread work struct contained in the master struct
1251 */
1252static void spi_pump_messages(struct kthread_work *work)
1253{
1254 struct spi_master *master =
1255 container_of(work, struct spi_master, pump_messages);
1256
1257 __spi_pump_messages(master, true);
1258}
1259
1260static int spi_init_queue(struct spi_master *master)
1261{
1262 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1263
1264 master->running = false;
1265 master->busy = false;
1266
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);
1274 }
1275 kthread_init_work(&master->pump_messages, spi_pump_messages);
1276
1277 /*
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.
1283 */
1284 if (master->rt) {
1285 dev_info(&master->dev,
1286 "will run message pump with realtime priority\n");
1287 sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m);
1288 }
1289
1290 return 0;
1291}
1292
1293/**
1294 * spi_get_next_queued_message() - called by driver to check for queued
1295 * messages
1296 * @master: the master to check for queued messages
1297 *
1298 * If there are more messages in the queue, the next message is returned from
1299 * this call.
1300 *
1301 * Return: the next message in the queue, else NULL if the queue is empty.
1302 */
1303struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1304{
1305 struct spi_message *next;
1306 unsigned long flags;
1307
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,
1311 queue);
1312 spin_unlock_irqrestore(&master->queue_lock, flags);
1313
1314 return next;
1315}
1316EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1317
1318/**
1319 * spi_finalize_current_message() - the current message is complete
1320 * @master: the master to return the message to
1321 *
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.
1324 */
1325void spi_finalize_current_message(struct spi_master *master)
1326{
1327 struct spi_message *mesg;
1328 unsigned long flags;
1329 int ret;
1330
1331 spin_lock_irqsave(&master->queue_lock, flags);
1332 mesg = master->cur_msg;
1333 spin_unlock_irqrestore(&master->queue_lock, flags);
1334
1335 spi_unmap_msg(master, mesg);
1336
1337 if (master->cur_msg_prepared && master->unprepare_message) {
1338 ret = master->unprepare_message(master, mesg);
1339 if (ret) {
1340 dev_err(&master->dev,
1341 "failed to unprepare message: %d\n", ret);
1342 }
1343 }
1344
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);
1350
1351 trace_spi_message_done(mesg);
1352
1353 mesg->state = NULL;
1354 if (mesg->complete)
1355 mesg->complete(mesg->context);
1356}
1357EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1358
1359static int spi_start_queue(struct spi_master *master)
1360{
1361 unsigned long flags;
1362
1363 spin_lock_irqsave(&master->queue_lock, flags);
1364
1365 if (master->running || master->busy) {
1366 spin_unlock_irqrestore(&master->queue_lock, flags);
1367 return -EBUSY;
1368 }
1369
1370 master->running = true;
1371 master->cur_msg = NULL;
1372 spin_unlock_irqrestore(&master->queue_lock, flags);
1373
1374 kthread_queue_work(&master->kworker, &master->pump_messages);
1375
1376 return 0;
1377}
1378
1379static int spi_stop_queue(struct spi_master *master)
1380{
1381 unsigned long flags;
1382 unsigned limit = 500;
1383 int ret = 0;
1384
1385 spin_lock_irqsave(&master->queue_lock, flags);
1386
1387 /*
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.
1392 */
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);
1397 }
1398
1399 if (!list_empty(&master->queue) || master->busy)
1400 ret = -EBUSY;
1401 else
1402 master->running = false;
1403
1404 spin_unlock_irqrestore(&master->queue_lock, flags);
1405
1406 if (ret) {
1407 dev_warn(&master->dev,
1408 "could not stop message queue\n");
1409 return ret;
1410 }
1411 return ret;
1412}
1413
1414static int spi_destroy_queue(struct spi_master *master)
1415{
1416 int ret;
1417
1418 ret = spi_stop_queue(master);
1419
1420 /*
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
1424 * return anyway.
1425 */
1426 if (ret) {
1427 dev_err(&master->dev, "problem destroying queue\n");
1428 return ret;
1429 }
1430
1431 kthread_flush_worker(&master->kworker);
1432 kthread_stop(master->kworker_task);
1433
1434 return 0;
1435}
1436
1437static int __spi_queued_transfer(struct spi_device *spi,
1438 struct spi_message *msg,
1439 bool need_pump)
1440{
1441 struct spi_master *master = spi->master;
1442 unsigned long flags;
1443
1444 spin_lock_irqsave(&master->queue_lock, flags);
1445
1446 if (!master->running) {
1447 spin_unlock_irqrestore(&master->queue_lock, flags);
1448 return -ESHUTDOWN;
1449 }
1450 msg->actual_length = 0;
1451 msg->status = -EINPROGRESS;
1452
1453 list_add_tail(&msg->queue, &master->queue);
1454 if (!master->busy && need_pump)
1455 kthread_queue_work(&master->kworker, &master->pump_messages);
1456
1457 spin_unlock_irqrestore(&master->queue_lock, flags);
1458 return 0;
1459}
1460
1461/**
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
1465 *
1466 * Return: zero on success, else a negative error code.
1467 */
1468static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1469{
1470 return __spi_queued_transfer(spi, msg, true);
1471}
1472
1473static int spi_master_initialize_queue(struct spi_master *master)
1474{
1475 int ret;
1476
1477 master->transfer = spi_queued_transfer;
1478 if (!master->transfer_one_message)
1479 master->transfer_one_message = spi_transfer_one_message;
1480
1481 /* Initialize and start queue */
1482 ret = spi_init_queue(master);
1483 if (ret) {
1484 dev_err(&master->dev, "problem initializing queue\n");
1485 goto err_init_queue;
1486 }
1487 master->queued = true;
1488 ret = spi_start_queue(master);
1489 if (ret) {
1490 dev_err(&master->dev, "problem starting queue\n");
1491 goto err_start_queue;
1492 }
1493
1494 return 0;
1495
1496err_start_queue:
1497 spi_destroy_queue(master);
1498err_init_queue:
1499 return ret;
1500}
1501
1502/*-------------------------------------------------------------------------*/
1503
1504#if defined(CONFIG_OF)
1505static struct spi_device *
1506of_register_spi_device(struct spi_master *master, struct device_node *nc)
1507{
1508 struct spi_device *spi;
1509 int rc;
1510 u32 value;
1511
1512 /* Alloc an spi_device */
1513 spi = spi_alloc_device(master);
1514 if (!spi) {
1515 dev_err(&master->dev, "spi_device alloc error for %s\n",
1516 nc->full_name);
1517 rc = -ENOMEM;
1518 goto err_out;
1519 }
1520
1521 /* Select device driver */
1522 rc = of_modalias_node(nc, spi->modalias,
1523 sizeof(spi->modalias));
1524 if (rc < 0) {
1525 dev_err(&master->dev, "cannot find modalias for %s\n",
1526 nc->full_name);
1527 goto err_out;
1528 }
1529
1530 /* Device address */
1531 rc = of_property_read_u32(nc, "reg", &value);
1532 if (rc) {
1533 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1534 nc->full_name, rc);
1535 goto err_out;
1536 }
1537 spi->chip_select = value;
1538
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;
1550
1551 /* Device DUAL/QUAD mode */
1552 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1553 switch (value) {
1554 case 1:
1555 break;
1556 case 2:
1557 spi->mode |= SPI_TX_DUAL;
1558 break;
1559 case 4:
1560 spi->mode |= SPI_TX_QUAD;
1561 break;
1562 default:
1563 dev_warn(&master->dev,
1564 "spi-tx-bus-width %d not supported\n",
1565 value);
1566 break;
1567 }
1568 }
1569
1570 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1571 switch (value) {
1572 case 1:
1573 break;
1574 case 2:
1575 spi->mode |= SPI_RX_DUAL;
1576 break;
1577 case 4:
1578 spi->mode |= SPI_RX_QUAD;
1579 break;
1580 default:
1581 dev_warn(&master->dev,
1582 "spi-rx-bus-width %d not supported\n",
1583 value);
1584 break;
1585 }
1586 }
1587
1588 /* Device speed */
1589 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1590 if (rc) {
1591 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1592 nc->full_name, rc);
1593 goto err_out;
1594 }
1595 spi->max_speed_hz = value;
1596
1597 /* Store a pointer to the node in the device structure */
1598 of_node_get(nc);
1599 spi->dev.of_node = nc;
1600
1601 /* Register the new device */
1602 rc = spi_add_device(spi);
1603 if (rc) {
1604 dev_err(&master->dev, "spi_device register error %s\n",
1605 nc->full_name);
1606 goto err_out;
1607 }
1608
1609 return spi;
1610
1611err_out:
1612 spi_dev_put(spi);
1613 return ERR_PTR(rc);
1614}
1615
1616/**
1617 * of_register_spi_devices() - Register child devices onto the SPI bus
1618 * @master: Pointer to spi_master device
1619 *
1620 * Registers an spi_device for each child node of master node which has a 'reg'
1621 * property.
1622 */
1623static void of_register_spi_devices(struct spi_master *master)
1624{
1625 struct spi_device *spi;
1626 struct device_node *nc;
1627
1628 if (!master->dev.of_node)
1629 return;
1630
1631 for_each_available_child_of_node(master->dev.of_node, nc) {
1632 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1633 continue;
1634 spi = of_register_spi_device(master, nc);
1635 if (IS_ERR(spi)) {
1636 dev_warn(&master->dev, "Failed to create SPI device for %s\n",
1637 nc->full_name);
1638 of_node_clear_flag(nc, OF_POPULATED);
1639 }
1640 }
1641}
1642#else
1643static void of_register_spi_devices(struct spi_master *master) { }
1644#endif
1645
1646#ifdef CONFIG_ACPI
1647static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1648{
1649 struct spi_device *spi = data;
1650 struct spi_master *master = spi->master;
1651
1652 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1653 struct acpi_resource_spi_serialbus *sb;
1654
1655 sb = &ares->data.spi_serial_bus;
1656 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1657 /*
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.
1663 */
1664 if (master->fw_translate_cs) {
1665 int cs = master->fw_translate_cs(master,
1666 sb->device_selection);
1667 if (cs < 0)
1668 return cs;
1669 spi->chip_select = cs;
1670 } else {
1671 spi->chip_select = sb->device_selection;
1672 }
1673
1674 spi->max_speed_hz = sb->connection_speed;
1675
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;
1682 }
1683 } else if (spi->irq < 0) {
1684 struct resource r;
1685
1686 if (acpi_dev_resource_interrupt(ares, 0, &r))
1687 spi->irq = r.start;
1688 }
1689
1690 /* Always tell the ACPI core to skip this resource */
1691 return 1;
1692}
1693
1694static acpi_status acpi_register_spi_device(struct spi_master *master,
1695 struct acpi_device *adev)
1696{
1697 struct list_head resource_list;
1698 struct spi_device *spi;
1699 int ret;
1700
1701 if (acpi_bus_get_status(adev) || !adev->status.present ||
1702 acpi_device_enumerated(adev))
1703 return AE_OK;
1704
1705 spi = spi_alloc_device(master);
1706 if (!spi) {
1707 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1708 dev_name(&adev->dev));
1709 return AE_NO_MEMORY;
1710 }
1711
1712 ACPI_COMPANION_SET(&spi->dev, adev);
1713 spi->irq = -1;
1714
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);
1719
1720 if (ret < 0 || !spi->max_speed_hz) {
1721 spi_dev_put(spi);
1722 return AE_OK;
1723 }
1724
1725 if (spi->irq < 0)
1726 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1727
1728 acpi_device_set_enumerated(adev);
1729
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));
1736 spi_dev_put(spi);
1737 }
1738
1739 return AE_OK;
1740}
1741
1742static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1743 void *data, void **return_value)
1744{
1745 struct spi_master *master = data;
1746 struct acpi_device *adev;
1747
1748 if (acpi_bus_get_device(handle, &adev))
1749 return AE_OK;
1750
1751 return acpi_register_spi_device(master, adev);
1752}
1753
1754static void acpi_register_spi_devices(struct spi_master *master)
1755{
1756 acpi_status status;
1757 acpi_handle handle;
1758
1759 handle = ACPI_HANDLE(master->dev.parent);
1760 if (!handle)
1761 return;
1762
1763 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1764 acpi_spi_add_device, NULL,
1765 master, NULL);
1766 if (ACPI_FAILURE(status))
1767 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1768}
1769#else
1770static inline void acpi_register_spi_devices(struct spi_master *master) {}
1771#endif /* CONFIG_ACPI */
1772
1773static void spi_master_release(struct device *dev)
1774{
1775 struct spi_master *master;
1776
1777 master = container_of(dev, struct spi_master, dev);
1778 kfree(master);
1779}
1780
1781static 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,
1786};
1787
1788
1789/**
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
1796 *
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().
1800 *
1801 * This must be called from context that can sleep.
1802 *
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.
1806 *
1807 * Return: the SPI master structure on success, else NULL.
1808 */
1809struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
1810{
1811 struct spi_master *master;
1812
1813 if (!dev)
1814 return NULL;
1815
1816 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
1817 if (!master)
1818 return NULL;
1819
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]);
1827
1828 return master;
1829}
1830EXPORT_SYMBOL_GPL(spi_alloc_master);
1831
1832#ifdef CONFIG_OF
1833static int of_spi_register_master(struct spi_master *master)
1834{
1835 int nb, i, *cs;
1836 struct device_node *np = master->dev.of_node;
1837
1838 if (!np)
1839 return 0;
1840
1841 nb = of_gpio_named_count(np, "cs-gpios");
1842 master->num_chipselect = max_t(int, nb, master->num_chipselect);
1843
1844 /* Return error only for an incorrectly formed cs-gpios property */
1845 if (nb == 0 || nb == -ENOENT)
1846 return 0;
1847 else if (nb < 0)
1848 return nb;
1849
1850 cs = devm_kzalloc(&master->dev,
1851 sizeof(int) * master->num_chipselect,
1852 GFP_KERNEL);
1853 master->cs_gpios = cs;
1854
1855 if (!master->cs_gpios)
1856 return -ENOMEM;
1857
1858 for (i = 0; i < master->num_chipselect; i++)
1859 cs[i] = -ENOENT;
1860
1861 for (i = 0; i < nb; i++)
1862 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1863
1864 return 0;
1865}
1866#else
1867static int of_spi_register_master(struct spi_master *master)
1868{
1869 return 0;
1870}
1871#endif
1872
1873/**
1874 * spi_register_master - register SPI master controller
1875 * @master: initialized master, originally from spi_alloc_master()
1876 * Context: can sleep
1877 *
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.
1881 *
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.
1887 *
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().
1892 *
1893 * Return: zero on success, else a negative error code.
1894 */
1895int spi_register_master(struct spi_master *master)
1896{
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;
1901 int dynamic = 0;
1902
1903 if (!dev)
1904 return -ENODEV;
1905
1906 status = of_spi_register_master(master);
1907 if (status)
1908 return status;
1909
1910 /* even if it's just one always-selected device, there must
1911 * be at least one chipselect
1912 */
1913 if (master->num_chipselect == 0)
1914 return -EINVAL;
1915
1916 if ((master->bus_num < 0) && master->dev.of_node)
1917 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1918
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
1923 */
1924 master->bus_num = atomic_dec_return(&dyn_bus_id);
1925 dynamic = 1;
1926 }
1927
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;
1937
1938 /* register the device, then userspace will see it.
1939 * registration fails if the bus ID is in use.
1940 */
1941 dev_set_name(&master->dev, "spi%u", master->bus_num);
1942 status = device_add(&master->dev);
1943 if (status < 0)
1944 goto done;
1945 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
1946 dynamic ? " (dynamic)" : "");
1947
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");
1951 else {
1952 status = spi_master_initialize_queue(master);
1953 if (status) {
1954 device_del(&master->dev);
1955 goto done;
1956 }
1957 }
1958 /* add statistics */
1959 spin_lock_init(&master->statistics.lock);
1960
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);
1966
1967 /* Register devices from the device tree and ACPI */
1968 of_register_spi_devices(master);
1969 acpi_register_spi_devices(master);
1970done:
1971 return status;
1972}
1973EXPORT_SYMBOL_GPL(spi_register_master);
1974
1975static void devm_spi_unregister(struct device *dev, void *res)
1976{
1977 spi_unregister_master(*(struct spi_master **)res);
1978}
1979
1980/**
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
1985 *
1986 * Register a SPI device as with spi_register_master() which will
1987 * automatically be unregister
1988 *
1989 * Return: zero on success, else a negative error code.
1990 */
1991int devm_spi_register_master(struct device *dev, struct spi_master *master)
1992{
1993 struct spi_master **ptr;
1994 int ret;
1995
1996 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
1997 if (!ptr)
1998 return -ENOMEM;
1999
2000 ret = spi_register_master(master);
2001 if (!ret) {
2002 *ptr = master;
2003 devres_add(dev, ptr);
2004 } else {
2005 devres_free(ptr);
2006 }
2007
2008 return ret;
2009}
2010EXPORT_SYMBOL_GPL(devm_spi_register_master);
2011
2012static int __unregister(struct device *dev, void *null)
2013{
2014 spi_unregister_device(to_spi_device(dev));
2015 return 0;
2016}
2017
2018/**
2019 * spi_unregister_master - unregister SPI master controller
2020 * @master: the master being unregistered
2021 * Context: can sleep
2022 *
2023 * This call is used only by SPI master controller drivers, which are the
2024 * only ones directly touching chip registers.
2025 *
2026 * This must be called from context that can sleep.
2027 */
2028void spi_unregister_master(struct spi_master *master)
2029{
2030 int dummy;
2031
2032 if (master->queued) {
2033 if (spi_destroy_queue(master))
2034 dev_err(&master->dev, "queue remove failed\n");
2035 }
2036
2037 mutex_lock(&board_lock);
2038 list_del(&master->list);
2039 mutex_unlock(&board_lock);
2040
2041 dummy = device_for_each_child(&master->dev, NULL, __unregister);
2042 device_unregister(&master->dev);
2043}
2044EXPORT_SYMBOL_GPL(spi_unregister_master);
2045
2046int spi_master_suspend(struct spi_master *master)
2047{
2048 int ret;
2049
2050 /* Basically no-ops for non-queued masters */
2051 if (!master->queued)
2052 return 0;
2053
2054 ret = spi_stop_queue(master);
2055 if (ret)
2056 dev_err(&master->dev, "queue stop failed\n");
2057
2058 return ret;
2059}
2060EXPORT_SYMBOL_GPL(spi_master_suspend);
2061
2062int spi_master_resume(struct spi_master *master)
2063{
2064 int ret;
2065
2066 if (!master->queued)
2067 return 0;
2068
2069 ret = spi_start_queue(master);
2070 if (ret)
2071 dev_err(&master->dev, "queue restart failed\n");
2072
2073 return ret;
2074}
2075EXPORT_SYMBOL_GPL(spi_master_resume);
2076
2077static int __spi_master_match(struct device *dev, const void *data)
2078{
2079 struct spi_master *m;
2080 const u16 *bus_num = data;
2081
2082 m = container_of(dev, struct spi_master, dev);
2083 return m->bus_num == *bus_num;
2084}
2085
2086/**
2087 * spi_busnum_to_master - look up master associated with bus_num
2088 * @bus_num: the master's bus number
2089 * Context: can sleep
2090 *
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.
2095 *
2096 * Return: the SPI master structure on success, else NULL.
2097 */
2098struct spi_master *spi_busnum_to_master(u16 bus_num)
2099{
2100 struct device *dev;
2101 struct spi_master *master = NULL;
2102
2103 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2104 __spi_master_match);
2105 if (dev)
2106 master = container_of(dev, struct spi_master, dev);
2107 /* reference got in class_find_device */
2108 return master;
2109}
2110EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2111
2112/*-------------------------------------------------------------------------*/
2113
2114/* Core methods for SPI resource management */
2115
2116/**
2117 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2118 * during the processing of a spi_message while using
2119 * spi_transfer_one
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
2124 *
2125 * Return: the pointer to the allocated data
2126 *
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.
2129 */
2130void *spi_res_alloc(struct spi_device *spi,
2131 spi_res_release_t release,
2132 size_t size, gfp_t gfp)
2133{
2134 struct spi_res *sres;
2135
2136 sres = kzalloc(sizeof(*sres) + size, gfp);
2137 if (!sres)
2138 return NULL;
2139
2140 INIT_LIST_HEAD(&sres->entry);
2141 sres->release = release;
2142
2143 return sres->data;
2144}
2145EXPORT_SYMBOL_GPL(spi_res_alloc);
2146
2147/**
2148 * spi_res_free - free an spi resource
2149 * @res: pointer to the custom data of a resource
2150 *
2151 */
2152void spi_res_free(void *res)
2153{
2154 struct spi_res *sres = container_of(res, struct spi_res, data);
2155
2156 if (!res)
2157 return;
2158
2159 WARN_ON(!list_empty(&sres->entry));
2160 kfree(sres);
2161}
2162EXPORT_SYMBOL_GPL(spi_res_free);
2163
2164/**
2165 * spi_res_add - add a spi_res to the spi_message
2166 * @message: the spi message
2167 * @res: the spi_resource
2168 */
2169void spi_res_add(struct spi_message *message, void *res)
2170{
2171 struct spi_res *sres = container_of(res, struct spi_res, data);
2172
2173 WARN_ON(!list_empty(&sres->entry));
2174 list_add_tail(&sres->entry, &message->resources);
2175}
2176EXPORT_SYMBOL_GPL(spi_res_add);
2177
2178/**
2179 * spi_res_release - release all spi resources for this message
2180 * @master: the @spi_master
2181 * @message: the @spi_message
2182 */
2183void spi_res_release(struct spi_master *master,
2184 struct spi_message *message)
2185{
2186 struct spi_res *res;
2187
2188 while (!list_empty(&message->resources)) {
2189 res = list_last_entry(&message->resources,
2190 struct spi_res, entry);
2191
2192 if (res->release)
2193 res->release(master, message, res->data);
2194
2195 list_del(&res->entry);
2196
2197 kfree(res);
2198 }
2199}
2200EXPORT_SYMBOL_GPL(spi_res_release);
2201
2202/*-------------------------------------------------------------------------*/
2203
2204/* Core methods for spi_message alterations */
2205
2206static void __spi_replace_transfers_release(struct spi_master *master,
2207 struct spi_message *msg,
2208 void *res)
2209{
2210 struct spi_replaced_transfers *rxfer = res;
2211 size_t i;
2212
2213 /* call extra callback if requested */
2214 if (rxfer->release)
2215 rxfer->release(master, msg, res);
2216
2217 /* insert replaced transfers back into the message */
2218 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2219
2220 /* remove the formerly inserted entries */
2221 for (i = 0; i < rxfer->inserted; i++)
2222 list_del(&rxfer->inserted_transfers[i].transfer_list);
2223}
2224
2225/**
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)
2235 * @gfp: gfp flags
2236 *
2237 * Returns: pointer to @spi_replaced_transfers,
2238 * PTR_ERR(...) in case of errors.
2239 */
2240struct spi_replaced_transfers *spi_replace_transfers(
2241 struct spi_message *msg,
2242 struct spi_transfer *xfer_first,
2243 size_t remove,
2244 size_t insert,
2245 spi_replaced_release_t release,
2246 size_t extradatasize,
2247 gfp_t gfp)
2248{
2249 struct spi_replaced_transfers *rxfer;
2250 struct spi_transfer *xfer;
2251 size_t i;
2252
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)
2257 + extradatasize,
2258 gfp);
2259 if (!rxfer)
2260 return ERR_PTR(-ENOMEM);
2261
2262 /* the release code to invoke before running the generic release */
2263 rxfer->release = release;
2264
2265 /* assign extradata */
2266 if (extradatasize)
2267 rxfer->extradata =
2268 &rxfer->inserted_transfers[insert];
2269
2270 /* init the replaced_transfers list */
2271 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2272
2273 /* assign the list_entry after which we should reinsert
2274 * the @replaced_transfers - it may be spi_message.messages!
2275 */
2276 rxfer->replaced_after = xfer_first->transfer_list.prev;
2277
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
2283 */
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);
2290
2291 /* free the spi_replace_transfer structure */
2292 spi_res_free(rxfer);
2293
2294 /* and return with an error */
2295 return ERR_PTR(-EINVAL);
2296 }
2297
2298 /* remove the entry after replaced_after from list of
2299 * transfers and add it to list of replaced_transfers
2300 */
2301 list_move_tail(rxfer->replaced_after->next,
2302 &rxfer->replaced_transfers);
2303 }
2304
2305 /* create copy of the given xfer with identical settings
2306 * based on the first transfer to get removed
2307 */
2308 for (i = 0; i < insert; i++) {
2309 /* we need to run in reverse order */
2310 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2311
2312 /* copy all spi_transfer data */
2313 memcpy(xfer, xfer_first, sizeof(*xfer));
2314
2315 /* add to list */
2316 list_add(&xfer->transfer_list, rxfer->replaced_after);
2317
2318 /* clear cs_change and delay_usecs for all but the last */
2319 if (i) {
2320 xfer->cs_change = false;
2321 xfer->delay_usecs = 0;
2322 }
2323 }
2324
2325 /* set up inserted */
2326 rxfer->inserted = insert;
2327
2328 /* and register it with spi_res/spi_message */
2329 spi_res_add(msg, rxfer);
2330
2331 return rxfer;
2332}
2333EXPORT_SYMBOL_GPL(spi_replace_transfers);
2334
2335static int __spi_split_transfer_maxsize(struct spi_master *master,
2336 struct spi_message *msg,
2337 struct spi_transfer **xferp,
2338 size_t maxsize,
2339 gfp_t gfp)
2340{
2341 struct spi_transfer *xfer = *xferp, *xfers;
2342 struct spi_replaced_transfers *srt;
2343 size_t offset;
2344 size_t count, i;
2345
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);
2350
2351 /* calculate how many we have to replace */
2352 count = DIV_ROUND_UP(xfer->len, maxsize);
2353
2354 /* create replacement */
2355 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
2356 if (IS_ERR(srt))
2357 return PTR_ERR(srt);
2358 xfers = srt->inserted_transfers;
2359
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.
2365 *
2366 * this also includes support for the depreciated
2367 * spi_message.is_dma_mapped interface
2368 */
2369
2370 /* the first transfer just needs the length modified, so we
2371 * run it outside the loop
2372 */
2373 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
2374
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;
2386
2387 /* update length */
2388 xfers[i].len = min(maxsize, xfers[i].len - offset);
2389 }
2390
2391 /* we set up xferp to the last entry we have inserted,
2392 * so that we skip those already split transfers
2393 */
2394 *xferp = &xfers[count - 1];
2395
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);
2401
2402 return 0;
2403}
2404
2405/**
2406 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2407 * when an individual transfer exceeds a
2408 * certain size
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
2413 *
2414 * Return: status of transformation
2415 */
2416int spi_split_transfers_maxsize(struct spi_master *master,
2417 struct spi_message *msg,
2418 size_t maxsize,
2419 gfp_t gfp)
2420{
2421 struct spi_transfer *xfer;
2422 int ret;
2423
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
2429 */
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);
2434 if (ret)
2435 return ret;
2436 }
2437 }
2438
2439 return 0;
2440}
2441EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2442
2443/*-------------------------------------------------------------------------*/
2444
2445/* Core methods for SPI master protocol drivers. Some of the
2446 * other core methods are currently defined as inline functions.
2447 */
2448
2449static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2450{
2451 if (master->bits_per_word_mask) {
2452 /* Only 32 bits fit in the mask */
2453 if (bits_per_word > 32)
2454 return -EINVAL;
2455 if (!(master->bits_per_word_mask &
2456 SPI_BPW_MASK(bits_per_word)))
2457 return -EINVAL;
2458 }
2459
2460 return 0;
2461}
2462
2463/**
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
2467 *
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.
2475 *
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.
2480 *
2481 * Return: zero on success, else a negative error code.
2482 */
2483int spi_setup(struct spi_device *spi)
2484{
2485 unsigned bad_bits, ugly_bits;
2486 int status;
2487
2488 /* check mode to prevent that DUAL and QUAD set at the same time
2489 */
2490 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2491 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2492 dev_err(&spi->dev,
2493 "setup: can not select dual and quad at the same time\n");
2494 return -EINVAL;
2495 }
2496 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2497 */
2498 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2499 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2500 return -EINVAL;
2501 /* help drivers fail *cleanly* when they need options
2502 * that aren't supported with their current master
2503 */
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);
2507 if (ugly_bits) {
2508 dev_warn(&spi->dev,
2509 "setup: ignoring unsupported mode bits %x\n",
2510 ugly_bits);
2511 spi->mode &= ~ugly_bits;
2512 bad_bits &= ~ugly_bits;
2513 }
2514 if (bad_bits) {
2515 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
2516 bad_bits);
2517 return -EINVAL;
2518 }
2519
2520 if (!spi->bits_per_word)
2521 spi->bits_per_word = 8;
2522
2523 status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2524 if (status)
2525 return status;
2526
2527 if (!spi->max_speed_hz)
2528 spi->max_speed_hz = spi->master->max_speed_hz;
2529
2530 if (spi->master->setup)
2531 status = spi->master->setup(spi);
2532
2533 spi_set_cs(spi, false);
2534
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,
2542 status);
2543
2544 return status;
2545}
2546EXPORT_SYMBOL_GPL(spi_setup);
2547
2548static int __spi_validate(struct spi_device *spi, struct spi_message *message)
2549{
2550 struct spi_master *master = spi->master;
2551 struct spi_transfer *xfer;
2552 int w_size;
2553
2554 if (list_empty(&message->transfers))
2555 return -EINVAL;
2556
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.
2561 */
2562 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2563 || (spi->mode & SPI_3WIRE)) {
2564 unsigned flags = master->flags;
2565
2566 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2567 if (xfer->rx_buf && xfer->tx_buf)
2568 return -EINVAL;
2569 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2570 return -EINVAL;
2571 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2572 return -EINVAL;
2573 }
2574 }
2575
2576 /**
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.
2581 */
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;
2587
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;
2592
2593 if (master->max_speed_hz &&
2594 xfer->speed_hz > master->max_speed_hz)
2595 xfer->speed_hz = master->max_speed_hz;
2596
2597 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2598 return -EINVAL;
2599
2600 /*
2601 * SPI transfer length should be multiple of SPI word size
2602 * where SPI word size should be power-of-two multiple
2603 */
2604 if (xfer->bits_per_word <= 8)
2605 w_size = 1;
2606 else if (xfer->bits_per_word <= 16)
2607 w_size = 2;
2608 else
2609 w_size = 4;
2610
2611 /* No partial transfers accepted */
2612 if (xfer->len % w_size)
2613 return -EINVAL;
2614
2615 if (xfer->speed_hz && master->min_speed_hz &&
2616 xfer->speed_hz < master->min_speed_hz)
2617 return -EINVAL;
2618
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
2626 */
2627 if (xfer->tx_buf) {
2628 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2629 xfer->tx_nbits != SPI_NBITS_DUAL &&
2630 xfer->tx_nbits != SPI_NBITS_QUAD)
2631 return -EINVAL;
2632 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2633 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2634 return -EINVAL;
2635 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2636 !(spi->mode & SPI_TX_QUAD))
2637 return -EINVAL;
2638 }
2639 /* check transfer rx_nbits */
2640 if (xfer->rx_buf) {
2641 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2642 xfer->rx_nbits != SPI_NBITS_DUAL &&
2643 xfer->rx_nbits != SPI_NBITS_QUAD)
2644 return -EINVAL;
2645 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2646 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2647 return -EINVAL;
2648 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2649 !(spi->mode & SPI_RX_QUAD))
2650 return -EINVAL;
2651 }
2652 }
2653
2654 message->status = -EINPROGRESS;
2655
2656 return 0;
2657}
2658
2659static int __spi_async(struct spi_device *spi, struct spi_message *message)
2660{
2661 struct spi_master *master = spi->master;
2662
2663 message->spi = spi;
2664
2665 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2666 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2667
2668 trace_spi_message_submit(message);
2669
2670 return master->transfer(spi, message);
2671}
2672
2673/**
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)
2678 *
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.
2681 *
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.
2689 *
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.
2694 *
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.)
2701 *
2702 * Return: zero on success, else a negative error code.
2703 */
2704int spi_async(struct spi_device *spi, struct spi_message *message)
2705{
2706 struct spi_master *master = spi->master;
2707 int ret;
2708 unsigned long flags;
2709
2710 ret = __spi_validate(spi, message);
2711 if (ret != 0)
2712 return ret;
2713
2714 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2715
2716 if (master->bus_lock_flag)
2717 ret = -EBUSY;
2718 else
2719 ret = __spi_async(spi, message);
2720
2721 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2722
2723 return ret;
2724}
2725EXPORT_SYMBOL_GPL(spi_async);
2726
2727/**
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)
2732 *
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.
2735 *
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.
2743 *
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.
2748 *
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.)
2755 *
2756 * Return: zero on success, else a negative error code.
2757 */
2758int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2759{
2760 struct spi_master *master = spi->master;
2761 int ret;
2762 unsigned long flags;
2763
2764 ret = __spi_validate(spi, message);
2765 if (ret != 0)
2766 return ret;
2767
2768 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2769
2770 ret = __spi_async(spi, message);
2771
2772 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2773
2774 return ret;
2775
2776}
2777EXPORT_SYMBOL_GPL(spi_async_locked);
2778
2779
2780int spi_flash_read(struct spi_device *spi,
2781 struct spi_flash_read_message *msg)
2782
2783{
2784 struct spi_master *master = spi->master;
2785 struct device *rx_dev = NULL;
2786 int ret;
2787
2788 if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2789 msg->addr_nbits == SPI_NBITS_DUAL) &&
2790 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2791 return -EINVAL;
2792 if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2793 msg->addr_nbits == SPI_NBITS_QUAD) &&
2794 !(spi->mode & SPI_TX_QUAD))
2795 return -EINVAL;
2796 if (msg->data_nbits == SPI_NBITS_DUAL &&
2797 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2798 return -EINVAL;
2799 if (msg->data_nbits == SPI_NBITS_QUAD &&
2800 !(spi->mode & SPI_RX_QUAD))
2801 return -EINVAL;
2802
2803 if (master->auto_runtime_pm) {
2804 ret = pm_runtime_get_sync(master->dev.parent);
2805 if (ret < 0) {
2806 dev_err(&master->dev, "Failed to power device: %d\n",
2807 ret);
2808 return ret;
2809 }
2810 }
2811
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,
2817 msg->buf, msg->len,
2818 DMA_FROM_DEVICE);
2819 if (!ret)
2820 msg->cur_msg_mapped = true;
2821 }
2822 ret = master->spi_flash_read(spi, msg);
2823 if (msg->cur_msg_mapped)
2824 spi_unmap_buf(master, rx_dev, &msg->rx_sg,
2825 DMA_FROM_DEVICE);
2826 mutex_unlock(&master->io_mutex);
2827 mutex_unlock(&master->bus_lock_mutex);
2828
2829 if (master->auto_runtime_pm)
2830 pm_runtime_put(master->dev.parent);
2831
2832 return ret;
2833}
2834EXPORT_SYMBOL_GPL(spi_flash_read);
2835
2836/*-------------------------------------------------------------------------*/
2837
2838/* Utility methods for SPI master protocol drivers, layered on
2839 * top of the core. Some other utility methods are defined as
2840 * inline functions.
2841 */
2842
2843static void spi_complete(void *arg)
2844{
2845 complete(arg);
2846}
2847
2848static int __spi_sync(struct spi_device *spi, struct spi_message *message)
2849{
2850 DECLARE_COMPLETION_ONSTACK(done);
2851 int status;
2852 struct spi_master *master = spi->master;
2853 unsigned long flags;
2854
2855 status = __spi_validate(spi, message);
2856 if (status != 0)
2857 return status;
2858
2859 message->complete = spi_complete;
2860 message->context = &done;
2861 message->spi = spi;
2862
2863 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2864 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2865
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.
2870 */
2871 if (master->transfer == spi_queued_transfer) {
2872 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2873
2874 trace_spi_message_submit(message);
2875
2876 status = __spi_queued_transfer(spi, message, false);
2877
2878 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2879 } else {
2880 status = spi_async_locked(spi, message);
2881 }
2882
2883 if (status == 0) {
2884 /* Push out the messages in the calling context if we
2885 * can.
2886 */
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);
2893 }
2894
2895 wait_for_completion(&done);
2896 status = message->status;
2897 }
2898 message->context = NULL;
2899 return status;
2900}
2901
2902/**
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
2907 *
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.
2911 *
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.)
2917 *
2918 * Also, the caller is guaranteeing that the memory associated with the
2919 * message will not be freed before this call returns.
2920 *
2921 * Return: zero on success, else a negative error code.
2922 */
2923int spi_sync(struct spi_device *spi, struct spi_message *message)
2924{
2925 int ret;
2926
2927 mutex_lock(&spi->master->bus_lock_mutex);
2928 ret = __spi_sync(spi, message);
2929 mutex_unlock(&spi->master->bus_lock_mutex);
2930
2931 return ret;
2932}
2933EXPORT_SYMBOL_GPL(spi_sync);
2934
2935/**
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
2940 *
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.
2944 *
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.
2948 *
2949 * Return: zero on success, else a negative error code.
2950 */
2951int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2952{
2953 return __spi_sync(spi, message);
2954}
2955EXPORT_SYMBOL_GPL(spi_sync_locked);
2956
2957/**
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
2961 *
2962 * This call may only be used from a context that may sleep. The sleep
2963 * is non-interruptible, and has no timeout.
2964 *
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.
2969 *
2970 * Return: always zero.
2971 */
2972int spi_bus_lock(struct spi_master *master)
2973{
2974 unsigned long flags;
2975
2976 mutex_lock(&master->bus_lock_mutex);
2977
2978 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2979 master->bus_lock_flag = 1;
2980 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2981
2982 /* mutex remains locked until spi_bus_unlock is called */
2983
2984 return 0;
2985}
2986EXPORT_SYMBOL_GPL(spi_bus_lock);
2987
2988/**
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
2992 *
2993 * This call may only be used from a context that may sleep. The sleep
2994 * is non-interruptible, and has no timeout.
2995 *
2996 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2997 * call.
2998 *
2999 * Return: always zero.
3000 */
3001int spi_bus_unlock(struct spi_master *master)
3002{
3003 master->bus_lock_flag = 0;
3004
3005 mutex_unlock(&master->bus_lock_mutex);
3006
3007 return 0;
3008}
3009EXPORT_SYMBOL_GPL(spi_bus_unlock);
3010
3011/* portable code must never pass more than 32 bytes */
3012#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3013
3014static u8 *buf;
3015
3016/**
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
3024 *
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.
3029 *
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.
3034 *
3035 * Return: zero on success, else a negative error code.
3036 */
3037int spi_write_then_read(struct spi_device *spi,
3038 const void *txbuf, unsigned n_tx,
3039 void *rxbuf, unsigned n_rx)
3040{
3041 static DEFINE_MUTEX(lock);
3042
3043 int status;
3044 struct spi_message message;
3045 struct spi_transfer x[2];
3046 u8 *local_buf;
3047
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.
3052 */
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);
3056 if (!local_buf)
3057 return -ENOMEM;
3058 } else {
3059 local_buf = buf;
3060 }
3061
3062 spi_message_init(&message);
3063 memset(x, 0, sizeof(x));
3064 if (n_tx) {
3065 x[0].len = n_tx;
3066 spi_message_add_tail(&x[0], &message);
3067 }
3068 if (n_rx) {
3069 x[1].len = n_rx;
3070 spi_message_add_tail(&x[1], &message);
3071 }
3072
3073 memcpy(local_buf, txbuf, n_tx);
3074 x[0].tx_buf = local_buf;
3075 x[1].rx_buf = local_buf + n_tx;
3076
3077 /* do the i/o */
3078 status = spi_sync(spi, &message);
3079 if (status == 0)
3080 memcpy(rxbuf, x[1].rx_buf, n_rx);
3081
3082 if (x[0].tx_buf == buf)
3083 mutex_unlock(&lock);
3084 else
3085 kfree(local_buf);
3086
3087 return status;
3088}
3089EXPORT_SYMBOL_GPL(spi_write_then_read);
3090
3091/*-------------------------------------------------------------------------*/
3092
3093#if IS_ENABLED(CONFIG_OF_DYNAMIC)
3094static int __spi_of_device_match(struct device *dev, void *data)
3095{
3096 return dev->of_node == data;
3097}
3098
3099/* must call put_device() when done with returned spi_device device */
3100static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3101{
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;
3105}
3106
3107static int __spi_of_master_match(struct device *dev, const void *data)
3108{
3109 return dev->of_node == data;
3110}
3111
3112/* the spi masters are not using spi_bus, so we find it with another way */
3113static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3114{
3115 struct device *dev;
3116
3117 dev = class_find_device(&spi_master_class, NULL, node,
3118 __spi_of_master_match);
3119 if (!dev)
3120 return NULL;
3121
3122 /* reference got in class_find_device */
3123 return container_of(dev, struct spi_master, dev);
3124}
3125
3126static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3127 void *arg)
3128{
3129 struct of_reconfig_data *rd = arg;
3130 struct spi_master *master;
3131 struct spi_device *spi;
3132
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);
3136 if (master == NULL)
3137 return NOTIFY_OK; /* not for us */
3138
3139 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3140 put_device(&master->dev);
3141 return NOTIFY_OK;
3142 }
3143
3144 spi = of_register_spi_device(master, rd->dn);
3145 put_device(&master->dev);
3146
3147 if (IS_ERR(spi)) {
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));
3152 }
3153 break;
3154
3155 case OF_RECONFIG_CHANGE_REMOVE:
3156 /* already depopulated? */
3157 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3158 return NOTIFY_OK;
3159
3160 /* find our device by node */
3161 spi = of_find_spi_device_by_node(rd->dn);
3162 if (spi == NULL)
3163 return NOTIFY_OK; /* no? not meant for us */
3164
3165 /* unregister takes one ref away */
3166 spi_unregister_device(spi);
3167
3168 /* and put the reference of the find */
3169 put_device(&spi->dev);
3170 break;
3171 }
3172
3173 return NOTIFY_OK;
3174}
3175
3176static struct notifier_block spi_of_notifier = {
3177 .notifier_call = of_spi_notify,
3178};
3179#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3180extern struct notifier_block spi_of_notifier;
3181#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3182
3183#if IS_ENABLED(CONFIG_ACPI)
3184static int spi_acpi_master_match(struct device *dev, const void *data)
3185{
3186 return ACPI_COMPANION(dev->parent) == data;
3187}
3188
3189static int spi_acpi_device_match(struct device *dev, void *data)
3190{
3191 return ACPI_COMPANION(dev) == data;
3192}
3193
3194static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device *adev)
3195{
3196 struct device *dev;
3197
3198 dev = class_find_device(&spi_master_class, NULL, adev,
3199 spi_acpi_master_match);
3200 if (!dev)
3201 return NULL;
3202
3203 return container_of(dev, struct spi_master, dev);
3204}
3205
3206static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3207{
3208 struct device *dev;
3209
3210 dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3211
3212 return dev ? to_spi_device(dev) : NULL;
3213}
3214
3215static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3216 void *arg)
3217{
3218 struct acpi_device *adev = arg;
3219 struct spi_master *master;
3220 struct spi_device *spi;
3221
3222 switch (value) {
3223 case ACPI_RECONFIG_DEVICE_ADD:
3224 master = acpi_spi_find_master_by_adev(adev->parent);
3225 if (!master)
3226 break;
3227
3228 acpi_register_spi_device(master, adev);
3229 put_device(&master->dev);
3230 break;
3231 case ACPI_RECONFIG_DEVICE_REMOVE:
3232 if (!acpi_device_enumerated(adev))
3233 break;
3234
3235 spi = acpi_spi_find_device_by_adev(adev);
3236 if (!spi)
3237 break;
3238
3239 spi_unregister_device(spi);
3240 put_device(&spi->dev);
3241 break;
3242 }
3243
3244 return NOTIFY_OK;
3245}
3246
3247static struct notifier_block spi_acpi_notifier = {
3248 .notifier_call = acpi_spi_notify,
3249};
3250#else
3251extern struct notifier_block spi_acpi_notifier;
3252#endif
3253
3254static int __init spi_init(void)
3255{
3256 int status;
3257
3258 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
3259 if (!buf) {
3260 status = -ENOMEM;
3261 goto err0;
3262 }
3263
3264 status = bus_register(&spi_bus_type);
3265 if (status < 0)
3266 goto err1;
3267
3268 status = class_register(&spi_master_class);
3269 if (status < 0)
3270 goto err2;
3271
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));
3276
3277 return 0;
3278
3279err2:
3280 bus_unregister(&spi_bus_type);
3281err1:
3282 kfree(buf);
3283 buf = NULL;
3284err0:
3285 return status;
3286}
3287
3288/* board_info is normally registered in arch_initcall(),
3289 * but even essential drivers wait till later
3290 *
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.
3294 */
3295postcore_initcall(spi_init);
3296