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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/property.h>
35#include <linux/export.h>
36#include <linux/sched/rt.h>
37#include <uapi/linux/sched/types.h>
38#include <linux/delay.h>
39#include <linux/kthread.h>
40#include <linux/ioport.h>
41#include <linux/acpi.h>
42#include <linux/highmem.h>
43#include <linux/idr.h>
44#include <linux/platform_data/x86/apple.h>
45
46#define CREATE_TRACE_POINTS
47#include <trace/events/spi.h>
48
49static DEFINE_IDR(spi_master_idr);
50
51static void spidev_release(struct device *dev)
52{
53 struct spi_device *spi = to_spi_device(dev);
54
55 /* spi controllers may cleanup for released devices */
56 if (spi->controller->cleanup)
57 spi->controller->cleanup(spi);
58
59 spi_controller_put(spi->controller);
60 kfree(spi);
61}
62
63static ssize_t
64modalias_show(struct device *dev, struct device_attribute *a, char *buf)
65{
66 const struct spi_device *spi = to_spi_device(dev);
67 int len;
68
69 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
70 if (len != -ENODEV)
71 return len;
72
73 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
74}
75static DEVICE_ATTR_RO(modalias);
76
77#define SPI_STATISTICS_ATTRS(field, file) \
78static ssize_t spi_controller_##field##_show(struct device *dev, \
79 struct device_attribute *attr, \
80 char *buf) \
81{ \
82 struct spi_controller *ctlr = container_of(dev, \
83 struct spi_controller, dev); \
84 return spi_statistics_##field##_show(&ctlr->statistics, buf); \
85} \
86static struct device_attribute dev_attr_spi_controller_##field = { \
87 .attr = { .name = file, .mode = 0444 }, \
88 .show = spi_controller_##field##_show, \
89}; \
90static ssize_t spi_device_##field##_show(struct device *dev, \
91 struct device_attribute *attr, \
92 char *buf) \
93{ \
94 struct spi_device *spi = to_spi_device(dev); \
95 return spi_statistics_##field##_show(&spi->statistics, buf); \
96} \
97static struct device_attribute dev_attr_spi_device_##field = { \
98 .attr = { .name = file, .mode = 0444 }, \
99 .show = spi_device_##field##_show, \
100}
101
102#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
103static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
104 char *buf) \
105{ \
106 unsigned long flags; \
107 ssize_t len; \
108 spin_lock_irqsave(&stat->lock, flags); \
109 len = sprintf(buf, format_string, stat->field); \
110 spin_unlock_irqrestore(&stat->lock, flags); \
111 return len; \
112} \
113SPI_STATISTICS_ATTRS(name, file)
114
115#define SPI_STATISTICS_SHOW(field, format_string) \
116 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
117 field, format_string)
118
119SPI_STATISTICS_SHOW(messages, "%lu");
120SPI_STATISTICS_SHOW(transfers, "%lu");
121SPI_STATISTICS_SHOW(errors, "%lu");
122SPI_STATISTICS_SHOW(timedout, "%lu");
123
124SPI_STATISTICS_SHOW(spi_sync, "%lu");
125SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
126SPI_STATISTICS_SHOW(spi_async, "%lu");
127
128SPI_STATISTICS_SHOW(bytes, "%llu");
129SPI_STATISTICS_SHOW(bytes_rx, "%llu");
130SPI_STATISTICS_SHOW(bytes_tx, "%llu");
131
132#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
133 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
134 "transfer_bytes_histo_" number, \
135 transfer_bytes_histo[index], "%lu")
136SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
137SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
138SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
139SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
140SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
141SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
142SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
143SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
144SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
145SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
146SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
147SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
148SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
149SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
150SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
151SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
152SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
153
154SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
155
156static struct attribute *spi_dev_attrs[] = {
157 &dev_attr_modalias.attr,
158 NULL,
159};
160
161static const struct attribute_group spi_dev_group = {
162 .attrs = spi_dev_attrs,
163};
164
165static struct attribute *spi_device_statistics_attrs[] = {
166 &dev_attr_spi_device_messages.attr,
167 &dev_attr_spi_device_transfers.attr,
168 &dev_attr_spi_device_errors.attr,
169 &dev_attr_spi_device_timedout.attr,
170 &dev_attr_spi_device_spi_sync.attr,
171 &dev_attr_spi_device_spi_sync_immediate.attr,
172 &dev_attr_spi_device_spi_async.attr,
173 &dev_attr_spi_device_bytes.attr,
174 &dev_attr_spi_device_bytes_rx.attr,
175 &dev_attr_spi_device_bytes_tx.attr,
176 &dev_attr_spi_device_transfer_bytes_histo0.attr,
177 &dev_attr_spi_device_transfer_bytes_histo1.attr,
178 &dev_attr_spi_device_transfer_bytes_histo2.attr,
179 &dev_attr_spi_device_transfer_bytes_histo3.attr,
180 &dev_attr_spi_device_transfer_bytes_histo4.attr,
181 &dev_attr_spi_device_transfer_bytes_histo5.attr,
182 &dev_attr_spi_device_transfer_bytes_histo6.attr,
183 &dev_attr_spi_device_transfer_bytes_histo7.attr,
184 &dev_attr_spi_device_transfer_bytes_histo8.attr,
185 &dev_attr_spi_device_transfer_bytes_histo9.attr,
186 &dev_attr_spi_device_transfer_bytes_histo10.attr,
187 &dev_attr_spi_device_transfer_bytes_histo11.attr,
188 &dev_attr_spi_device_transfer_bytes_histo12.attr,
189 &dev_attr_spi_device_transfer_bytes_histo13.attr,
190 &dev_attr_spi_device_transfer_bytes_histo14.attr,
191 &dev_attr_spi_device_transfer_bytes_histo15.attr,
192 &dev_attr_spi_device_transfer_bytes_histo16.attr,
193 &dev_attr_spi_device_transfers_split_maxsize.attr,
194 NULL,
195};
196
197static const struct attribute_group spi_device_statistics_group = {
198 .name = "statistics",
199 .attrs = spi_device_statistics_attrs,
200};
201
202static const struct attribute_group *spi_dev_groups[] = {
203 &spi_dev_group,
204 &spi_device_statistics_group,
205 NULL,
206};
207
208static struct attribute *spi_controller_statistics_attrs[] = {
209 &dev_attr_spi_controller_messages.attr,
210 &dev_attr_spi_controller_transfers.attr,
211 &dev_attr_spi_controller_errors.attr,
212 &dev_attr_spi_controller_timedout.attr,
213 &dev_attr_spi_controller_spi_sync.attr,
214 &dev_attr_spi_controller_spi_sync_immediate.attr,
215 &dev_attr_spi_controller_spi_async.attr,
216 &dev_attr_spi_controller_bytes.attr,
217 &dev_attr_spi_controller_bytes_rx.attr,
218 &dev_attr_spi_controller_bytes_tx.attr,
219 &dev_attr_spi_controller_transfer_bytes_histo0.attr,
220 &dev_attr_spi_controller_transfer_bytes_histo1.attr,
221 &dev_attr_spi_controller_transfer_bytes_histo2.attr,
222 &dev_attr_spi_controller_transfer_bytes_histo3.attr,
223 &dev_attr_spi_controller_transfer_bytes_histo4.attr,
224 &dev_attr_spi_controller_transfer_bytes_histo5.attr,
225 &dev_attr_spi_controller_transfer_bytes_histo6.attr,
226 &dev_attr_spi_controller_transfer_bytes_histo7.attr,
227 &dev_attr_spi_controller_transfer_bytes_histo8.attr,
228 &dev_attr_spi_controller_transfer_bytes_histo9.attr,
229 &dev_attr_spi_controller_transfer_bytes_histo10.attr,
230 &dev_attr_spi_controller_transfer_bytes_histo11.attr,
231 &dev_attr_spi_controller_transfer_bytes_histo12.attr,
232 &dev_attr_spi_controller_transfer_bytes_histo13.attr,
233 &dev_attr_spi_controller_transfer_bytes_histo14.attr,
234 &dev_attr_spi_controller_transfer_bytes_histo15.attr,
235 &dev_attr_spi_controller_transfer_bytes_histo16.attr,
236 &dev_attr_spi_controller_transfers_split_maxsize.attr,
237 NULL,
238};
239
240static const struct attribute_group spi_controller_statistics_group = {
241 .name = "statistics",
242 .attrs = spi_controller_statistics_attrs,
243};
244
245static const struct attribute_group *spi_master_groups[] = {
246 &spi_controller_statistics_group,
247 NULL,
248};
249
250void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
251 struct spi_transfer *xfer,
252 struct spi_controller *ctlr)
253{
254 unsigned long flags;
255 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
256
257 if (l2len < 0)
258 l2len = 0;
259
260 spin_lock_irqsave(&stats->lock, flags);
261
262 stats->transfers++;
263 stats->transfer_bytes_histo[l2len]++;
264
265 stats->bytes += xfer->len;
266 if ((xfer->tx_buf) &&
267 (xfer->tx_buf != ctlr->dummy_tx))
268 stats->bytes_tx += xfer->len;
269 if ((xfer->rx_buf) &&
270 (xfer->rx_buf != ctlr->dummy_rx))
271 stats->bytes_rx += xfer->len;
272
273 spin_unlock_irqrestore(&stats->lock, flags);
274}
275EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
276
277/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
278 * and the sysfs version makes coldplug work too.
279 */
280
281static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
282 const struct spi_device *sdev)
283{
284 while (id->name[0]) {
285 if (!strcmp(sdev->modalias, id->name))
286 return id;
287 id++;
288 }
289 return NULL;
290}
291
292const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
293{
294 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
295
296 return spi_match_id(sdrv->id_table, sdev);
297}
298EXPORT_SYMBOL_GPL(spi_get_device_id);
299
300static int spi_match_device(struct device *dev, struct device_driver *drv)
301{
302 const struct spi_device *spi = to_spi_device(dev);
303 const struct spi_driver *sdrv = to_spi_driver(drv);
304
305 /* Attempt an OF style match */
306 if (of_driver_match_device(dev, drv))
307 return 1;
308
309 /* Then try ACPI */
310 if (acpi_driver_match_device(dev, drv))
311 return 1;
312
313 if (sdrv->id_table)
314 return !!spi_match_id(sdrv->id_table, spi);
315
316 return strcmp(spi->modalias, drv->name) == 0;
317}
318
319static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
320{
321 const struct spi_device *spi = to_spi_device(dev);
322 int rc;
323
324 rc = acpi_device_uevent_modalias(dev, env);
325 if (rc != -ENODEV)
326 return rc;
327
328 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
329}
330
331struct bus_type spi_bus_type = {
332 .name = "spi",
333 .dev_groups = spi_dev_groups,
334 .match = spi_match_device,
335 .uevent = spi_uevent,
336};
337EXPORT_SYMBOL_GPL(spi_bus_type);
338
339
340static int spi_drv_probe(struct device *dev)
341{
342 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
343 struct spi_device *spi = to_spi_device(dev);
344 int ret;
345
346 ret = of_clk_set_defaults(dev->of_node, false);
347 if (ret)
348 return ret;
349
350 if (dev->of_node) {
351 spi->irq = of_irq_get(dev->of_node, 0);
352 if (spi->irq == -EPROBE_DEFER)
353 return -EPROBE_DEFER;
354 if (spi->irq < 0)
355 spi->irq = 0;
356 }
357
358 ret = dev_pm_domain_attach(dev, true);
359 if (ret != -EPROBE_DEFER) {
360 ret = sdrv->probe(spi);
361 if (ret)
362 dev_pm_domain_detach(dev, true);
363 }
364
365 return ret;
366}
367
368static int spi_drv_remove(struct device *dev)
369{
370 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
371 int ret;
372
373 ret = sdrv->remove(to_spi_device(dev));
374 dev_pm_domain_detach(dev, true);
375
376 return ret;
377}
378
379static void spi_drv_shutdown(struct device *dev)
380{
381 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
382
383 sdrv->shutdown(to_spi_device(dev));
384}
385
386/**
387 * __spi_register_driver - register a SPI driver
388 * @owner: owner module of the driver to register
389 * @sdrv: the driver to register
390 * Context: can sleep
391 *
392 * Return: zero on success, else a negative error code.
393 */
394int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
395{
396 sdrv->driver.owner = owner;
397 sdrv->driver.bus = &spi_bus_type;
398 if (sdrv->probe)
399 sdrv->driver.probe = spi_drv_probe;
400 if (sdrv->remove)
401 sdrv->driver.remove = spi_drv_remove;
402 if (sdrv->shutdown)
403 sdrv->driver.shutdown = spi_drv_shutdown;
404 return driver_register(&sdrv->driver);
405}
406EXPORT_SYMBOL_GPL(__spi_register_driver);
407
408/*-------------------------------------------------------------------------*/
409
410/* SPI devices should normally not be created by SPI device drivers; that
411 * would make them board-specific. Similarly with SPI controller drivers.
412 * Device registration normally goes into like arch/.../mach.../board-YYY.c
413 * with other readonly (flashable) information about mainboard devices.
414 */
415
416struct boardinfo {
417 struct list_head list;
418 struct spi_board_info board_info;
419};
420
421static LIST_HEAD(board_list);
422static LIST_HEAD(spi_controller_list);
423
424/*
425 * Used to protect add/del opertion for board_info list and
426 * spi_controller list, and their matching process
427 * also used to protect object of type struct idr
428 */
429static DEFINE_MUTEX(board_lock);
430
431/**
432 * spi_alloc_device - Allocate a new SPI device
433 * @ctlr: Controller to which device is connected
434 * Context: can sleep
435 *
436 * Allows a driver to allocate and initialize a spi_device without
437 * registering it immediately. This allows a driver to directly
438 * fill the spi_device with device parameters before calling
439 * spi_add_device() on it.
440 *
441 * Caller is responsible to call spi_add_device() on the returned
442 * spi_device structure to add it to the SPI controller. If the caller
443 * needs to discard the spi_device without adding it, then it should
444 * call spi_dev_put() on it.
445 *
446 * Return: a pointer to the new device, or NULL.
447 */
448struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
449{
450 struct spi_device *spi;
451
452 if (!spi_controller_get(ctlr))
453 return NULL;
454
455 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
456 if (!spi) {
457 spi_controller_put(ctlr);
458 return NULL;
459 }
460
461 spi->master = spi->controller = ctlr;
462 spi->dev.parent = &ctlr->dev;
463 spi->dev.bus = &spi_bus_type;
464 spi->dev.release = spidev_release;
465 spi->cs_gpio = -ENOENT;
466
467 spin_lock_init(&spi->statistics.lock);
468
469 device_initialize(&spi->dev);
470 return spi;
471}
472EXPORT_SYMBOL_GPL(spi_alloc_device);
473
474static void spi_dev_set_name(struct spi_device *spi)
475{
476 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
477
478 if (adev) {
479 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
480 return;
481 }
482
483 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
484 spi->chip_select);
485}
486
487static int spi_dev_check(struct device *dev, void *data)
488{
489 struct spi_device *spi = to_spi_device(dev);
490 struct spi_device *new_spi = data;
491
492 if (spi->controller == new_spi->controller &&
493 spi->chip_select == new_spi->chip_select)
494 return -EBUSY;
495 return 0;
496}
497
498/**
499 * spi_add_device - Add spi_device allocated with spi_alloc_device
500 * @spi: spi_device to register
501 *
502 * Companion function to spi_alloc_device. Devices allocated with
503 * spi_alloc_device can be added onto the spi bus with this function.
504 *
505 * Return: 0 on success; negative errno on failure
506 */
507int spi_add_device(struct spi_device *spi)
508{
509 static DEFINE_MUTEX(spi_add_lock);
510 struct spi_controller *ctlr = spi->controller;
511 struct device *dev = ctlr->dev.parent;
512 int status;
513
514 /* Chipselects are numbered 0..max; validate. */
515 if (spi->chip_select >= ctlr->num_chipselect) {
516 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
517 ctlr->num_chipselect);
518 return -EINVAL;
519 }
520
521 /* Set the bus ID string */
522 spi_dev_set_name(spi);
523
524 /* We need to make sure there's no other device with this
525 * chipselect **BEFORE** we call setup(), else we'll trash
526 * its configuration. Lock against concurrent add() calls.
527 */
528 mutex_lock(&spi_add_lock);
529
530 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
531 if (status) {
532 dev_err(dev, "chipselect %d already in use\n",
533 spi->chip_select);
534 goto done;
535 }
536
537 if (ctlr->cs_gpios)
538 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
539
540 /* Drivers may modify this initial i/o setup, but will
541 * normally rely on the device being setup. Devices
542 * using SPI_CS_HIGH can't coexist well otherwise...
543 */
544 status = spi_setup(spi);
545 if (status < 0) {
546 dev_err(dev, "can't setup %s, status %d\n",
547 dev_name(&spi->dev), status);
548 goto done;
549 }
550
551 /* Device may be bound to an active driver when this returns */
552 status = device_add(&spi->dev);
553 if (status < 0)
554 dev_err(dev, "can't add %s, status %d\n",
555 dev_name(&spi->dev), status);
556 else
557 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
558
559done:
560 mutex_unlock(&spi_add_lock);
561 return status;
562}
563EXPORT_SYMBOL_GPL(spi_add_device);
564
565/**
566 * spi_new_device - instantiate one new SPI device
567 * @ctlr: Controller to which device is connected
568 * @chip: Describes the SPI device
569 * Context: can sleep
570 *
571 * On typical mainboards, this is purely internal; and it's not needed
572 * after board init creates the hard-wired devices. Some development
573 * platforms may not be able to use spi_register_board_info though, and
574 * this is exported so that for example a USB or parport based adapter
575 * driver could add devices (which it would learn about out-of-band).
576 *
577 * Return: the new device, or NULL.
578 */
579struct spi_device *spi_new_device(struct spi_controller *ctlr,
580 struct spi_board_info *chip)
581{
582 struct spi_device *proxy;
583 int status;
584
585 /* NOTE: caller did any chip->bus_num checks necessary.
586 *
587 * Also, unless we change the return value convention to use
588 * error-or-pointer (not NULL-or-pointer), troubleshootability
589 * suggests syslogged diagnostics are best here (ugh).
590 */
591
592 proxy = spi_alloc_device(ctlr);
593 if (!proxy)
594 return NULL;
595
596 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
597
598 proxy->chip_select = chip->chip_select;
599 proxy->max_speed_hz = chip->max_speed_hz;
600 proxy->mode = chip->mode;
601 proxy->irq = chip->irq;
602 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
603 proxy->dev.platform_data = (void *) chip->platform_data;
604 proxy->controller_data = chip->controller_data;
605 proxy->controller_state = NULL;
606
607 if (chip->properties) {
608 status = device_add_properties(&proxy->dev, chip->properties);
609 if (status) {
610 dev_err(&ctlr->dev,
611 "failed to add properties to '%s': %d\n",
612 chip->modalias, status);
613 goto err_dev_put;
614 }
615 }
616
617 status = spi_add_device(proxy);
618 if (status < 0)
619 goto err_remove_props;
620
621 return proxy;
622
623err_remove_props:
624 if (chip->properties)
625 device_remove_properties(&proxy->dev);
626err_dev_put:
627 spi_dev_put(proxy);
628 return NULL;
629}
630EXPORT_SYMBOL_GPL(spi_new_device);
631
632/**
633 * spi_unregister_device - unregister a single SPI device
634 * @spi: spi_device to unregister
635 *
636 * Start making the passed SPI device vanish. Normally this would be handled
637 * by spi_unregister_controller().
638 */
639void spi_unregister_device(struct spi_device *spi)
640{
641 if (!spi)
642 return;
643
644 if (spi->dev.of_node) {
645 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
646 of_node_put(spi->dev.of_node);
647 }
648 if (ACPI_COMPANION(&spi->dev))
649 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
650 device_unregister(&spi->dev);
651}
652EXPORT_SYMBOL_GPL(spi_unregister_device);
653
654static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
655 struct spi_board_info *bi)
656{
657 struct spi_device *dev;
658
659 if (ctlr->bus_num != bi->bus_num)
660 return;
661
662 dev = spi_new_device(ctlr, bi);
663 if (!dev)
664 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
665 bi->modalias);
666}
667
668/**
669 * spi_register_board_info - register SPI devices for a given board
670 * @info: array of chip descriptors
671 * @n: how many descriptors are provided
672 * Context: can sleep
673 *
674 * Board-specific early init code calls this (probably during arch_initcall)
675 * with segments of the SPI device table. Any device nodes are created later,
676 * after the relevant parent SPI controller (bus_num) is defined. We keep
677 * this table of devices forever, so that reloading a controller driver will
678 * not make Linux forget about these hard-wired devices.
679 *
680 * Other code can also call this, e.g. a particular add-on board might provide
681 * SPI devices through its expansion connector, so code initializing that board
682 * would naturally declare its SPI devices.
683 *
684 * The board info passed can safely be __initdata ... but be careful of
685 * any embedded pointers (platform_data, etc), they're copied as-is.
686 * Device properties are deep-copied though.
687 *
688 * Return: zero on success, else a negative error code.
689 */
690int spi_register_board_info(struct spi_board_info const *info, unsigned n)
691{
692 struct boardinfo *bi;
693 int i;
694
695 if (!n)
696 return 0;
697
698 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
699 if (!bi)
700 return -ENOMEM;
701
702 for (i = 0; i < n; i++, bi++, info++) {
703 struct spi_controller *ctlr;
704
705 memcpy(&bi->board_info, info, sizeof(*info));
706 if (info->properties) {
707 bi->board_info.properties =
708 property_entries_dup(info->properties);
709 if (IS_ERR(bi->board_info.properties))
710 return PTR_ERR(bi->board_info.properties);
711 }
712
713 mutex_lock(&board_lock);
714 list_add_tail(&bi->list, &board_list);
715 list_for_each_entry(ctlr, &spi_controller_list, list)
716 spi_match_controller_to_boardinfo(ctlr,
717 &bi->board_info);
718 mutex_unlock(&board_lock);
719 }
720
721 return 0;
722}
723
724/*-------------------------------------------------------------------------*/
725
726static void spi_set_cs(struct spi_device *spi, bool enable)
727{
728 if (spi->mode & SPI_CS_HIGH)
729 enable = !enable;
730
731 if (gpio_is_valid(spi->cs_gpio)) {
732 gpio_set_value(spi->cs_gpio, !enable);
733 /* Some SPI masters need both GPIO CS & slave_select */
734 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
735 spi->controller->set_cs)
736 spi->controller->set_cs(spi, !enable);
737 } else if (spi->controller->set_cs) {
738 spi->controller->set_cs(spi, !enable);
739 }
740}
741
742#ifdef CONFIG_HAS_DMA
743static int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
744 struct sg_table *sgt, void *buf, size_t len,
745 enum dma_data_direction dir)
746{
747 const bool vmalloced_buf = is_vmalloc_addr(buf);
748 unsigned int max_seg_size = dma_get_max_seg_size(dev);
749#ifdef CONFIG_HIGHMEM
750 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
751 (unsigned long)buf < (PKMAP_BASE +
752 (LAST_PKMAP * PAGE_SIZE)));
753#else
754 const bool kmap_buf = false;
755#endif
756 int desc_len;
757 int sgs;
758 struct page *vm_page;
759 struct scatterlist *sg;
760 void *sg_buf;
761 size_t min;
762 int i, ret;
763
764 if (vmalloced_buf || kmap_buf) {
765 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
766 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
767 } else if (virt_addr_valid(buf)) {
768 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
769 sgs = DIV_ROUND_UP(len, desc_len);
770 } else {
771 return -EINVAL;
772 }
773
774 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
775 if (ret != 0)
776 return ret;
777
778 sg = &sgt->sgl[0];
779 for (i = 0; i < sgs; i++) {
780
781 if (vmalloced_buf || kmap_buf) {
782 /*
783 * Next scatterlist entry size is the minimum between
784 * the desc_len and the remaining buffer length that
785 * fits in a page.
786 */
787 min = min_t(size_t, desc_len,
788 min_t(size_t, len,
789 PAGE_SIZE - offset_in_page(buf)));
790 if (vmalloced_buf)
791 vm_page = vmalloc_to_page(buf);
792 else
793 vm_page = kmap_to_page(buf);
794 if (!vm_page) {
795 sg_free_table(sgt);
796 return -ENOMEM;
797 }
798 sg_set_page(sg, vm_page,
799 min, offset_in_page(buf));
800 } else {
801 min = min_t(size_t, len, desc_len);
802 sg_buf = buf;
803 sg_set_buf(sg, sg_buf, min);
804 }
805
806 buf += min;
807 len -= min;
808 sg = sg_next(sg);
809 }
810
811 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
812 if (!ret)
813 ret = -ENOMEM;
814 if (ret < 0) {
815 sg_free_table(sgt);
816 return ret;
817 }
818
819 sgt->nents = ret;
820
821 return 0;
822}
823
824static void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
825 struct sg_table *sgt, enum dma_data_direction dir)
826{
827 if (sgt->orig_nents) {
828 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
829 sg_free_table(sgt);
830 }
831}
832
833static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
834{
835 struct device *tx_dev, *rx_dev;
836 struct spi_transfer *xfer;
837 int ret;
838
839 if (!ctlr->can_dma)
840 return 0;
841
842 if (ctlr->dma_tx)
843 tx_dev = ctlr->dma_tx->device->dev;
844 else
845 tx_dev = ctlr->dev.parent;
846
847 if (ctlr->dma_rx)
848 rx_dev = ctlr->dma_rx->device->dev;
849 else
850 rx_dev = ctlr->dev.parent;
851
852 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
853 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
854 continue;
855
856 if (xfer->tx_buf != NULL) {
857 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
858 (void *)xfer->tx_buf, xfer->len,
859 DMA_TO_DEVICE);
860 if (ret != 0)
861 return ret;
862 }
863
864 if (xfer->rx_buf != NULL) {
865 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
866 xfer->rx_buf, xfer->len,
867 DMA_FROM_DEVICE);
868 if (ret != 0) {
869 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
870 DMA_TO_DEVICE);
871 return ret;
872 }
873 }
874 }
875
876 ctlr->cur_msg_mapped = true;
877
878 return 0;
879}
880
881static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
882{
883 struct spi_transfer *xfer;
884 struct device *tx_dev, *rx_dev;
885
886 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
887 return 0;
888
889 if (ctlr->dma_tx)
890 tx_dev = ctlr->dma_tx->device->dev;
891 else
892 tx_dev = ctlr->dev.parent;
893
894 if (ctlr->dma_rx)
895 rx_dev = ctlr->dma_rx->device->dev;
896 else
897 rx_dev = ctlr->dev.parent;
898
899 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
900 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
901 continue;
902
903 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
904 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
905 }
906
907 return 0;
908}
909#else /* !CONFIG_HAS_DMA */
910static inline int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
911 struct sg_table *sgt, void *buf, size_t len,
912 enum dma_data_direction dir)
913{
914 return -EINVAL;
915}
916
917static inline void spi_unmap_buf(struct spi_controller *ctlr,
918 struct device *dev, struct sg_table *sgt,
919 enum dma_data_direction dir)
920{
921}
922
923static inline int __spi_map_msg(struct spi_controller *ctlr,
924 struct spi_message *msg)
925{
926 return 0;
927}
928
929static inline int __spi_unmap_msg(struct spi_controller *ctlr,
930 struct spi_message *msg)
931{
932 return 0;
933}
934#endif /* !CONFIG_HAS_DMA */
935
936static inline int spi_unmap_msg(struct spi_controller *ctlr,
937 struct spi_message *msg)
938{
939 struct spi_transfer *xfer;
940
941 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
942 /*
943 * Restore the original value of tx_buf or rx_buf if they are
944 * NULL.
945 */
946 if (xfer->tx_buf == ctlr->dummy_tx)
947 xfer->tx_buf = NULL;
948 if (xfer->rx_buf == ctlr->dummy_rx)
949 xfer->rx_buf = NULL;
950 }
951
952 return __spi_unmap_msg(ctlr, msg);
953}
954
955static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
956{
957 struct spi_transfer *xfer;
958 void *tmp;
959 unsigned int max_tx, max_rx;
960
961 if (ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) {
962 max_tx = 0;
963 max_rx = 0;
964
965 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
966 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
967 !xfer->tx_buf)
968 max_tx = max(xfer->len, max_tx);
969 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
970 !xfer->rx_buf)
971 max_rx = max(xfer->len, max_rx);
972 }
973
974 if (max_tx) {
975 tmp = krealloc(ctlr->dummy_tx, max_tx,
976 GFP_KERNEL | GFP_DMA);
977 if (!tmp)
978 return -ENOMEM;
979 ctlr->dummy_tx = tmp;
980 memset(tmp, 0, max_tx);
981 }
982
983 if (max_rx) {
984 tmp = krealloc(ctlr->dummy_rx, max_rx,
985 GFP_KERNEL | GFP_DMA);
986 if (!tmp)
987 return -ENOMEM;
988 ctlr->dummy_rx = tmp;
989 }
990
991 if (max_tx || max_rx) {
992 list_for_each_entry(xfer, &msg->transfers,
993 transfer_list) {
994 if (!xfer->tx_buf)
995 xfer->tx_buf = ctlr->dummy_tx;
996 if (!xfer->rx_buf)
997 xfer->rx_buf = ctlr->dummy_rx;
998 }
999 }
1000 }
1001
1002 return __spi_map_msg(ctlr, msg);
1003}
1004
1005/*
1006 * spi_transfer_one_message - Default implementation of transfer_one_message()
1007 *
1008 * This is a standard implementation of transfer_one_message() for
1009 * drivers which implement a transfer_one() operation. It provides
1010 * standard handling of delays and chip select management.
1011 */
1012static int spi_transfer_one_message(struct spi_controller *ctlr,
1013 struct spi_message *msg)
1014{
1015 struct spi_transfer *xfer;
1016 bool keep_cs = false;
1017 int ret = 0;
1018 unsigned long long ms = 1;
1019 struct spi_statistics *statm = &ctlr->statistics;
1020 struct spi_statistics *stats = &msg->spi->statistics;
1021
1022 spi_set_cs(msg->spi, true);
1023
1024 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1025 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1026
1027 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1028 trace_spi_transfer_start(msg, xfer);
1029
1030 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1031 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1032
1033 if (xfer->tx_buf || xfer->rx_buf) {
1034 reinit_completion(&ctlr->xfer_completion);
1035
1036 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1037 if (ret < 0) {
1038 SPI_STATISTICS_INCREMENT_FIELD(statm,
1039 errors);
1040 SPI_STATISTICS_INCREMENT_FIELD(stats,
1041 errors);
1042 dev_err(&msg->spi->dev,
1043 "SPI transfer failed: %d\n", ret);
1044 goto out;
1045 }
1046
1047 if (ret > 0) {
1048 ret = 0;
1049 ms = 8LL * 1000LL * xfer->len;
1050 do_div(ms, xfer->speed_hz);
1051 ms += ms + 200; /* some tolerance */
1052
1053 if (ms > UINT_MAX)
1054 ms = UINT_MAX;
1055
1056 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1057 msecs_to_jiffies(ms));
1058 }
1059
1060 if (ms == 0) {
1061 SPI_STATISTICS_INCREMENT_FIELD(statm,
1062 timedout);
1063 SPI_STATISTICS_INCREMENT_FIELD(stats,
1064 timedout);
1065 dev_err(&msg->spi->dev,
1066 "SPI transfer timed out\n");
1067 msg->status = -ETIMEDOUT;
1068 }
1069 } else {
1070 if (xfer->len)
1071 dev_err(&msg->spi->dev,
1072 "Bufferless transfer has length %u\n",
1073 xfer->len);
1074 }
1075
1076 trace_spi_transfer_stop(msg, xfer);
1077
1078 if (msg->status != -EINPROGRESS)
1079 goto out;
1080
1081 if (xfer->delay_usecs) {
1082 u16 us = xfer->delay_usecs;
1083
1084 if (us <= 10)
1085 udelay(us);
1086 else
1087 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1088 }
1089
1090 if (xfer->cs_change) {
1091 if (list_is_last(&xfer->transfer_list,
1092 &msg->transfers)) {
1093 keep_cs = true;
1094 } else {
1095 spi_set_cs(msg->spi, false);
1096 udelay(10);
1097 spi_set_cs(msg->spi, true);
1098 }
1099 }
1100
1101 msg->actual_length += xfer->len;
1102 }
1103
1104out:
1105 if (ret != 0 || !keep_cs)
1106 spi_set_cs(msg->spi, false);
1107
1108 if (msg->status == -EINPROGRESS)
1109 msg->status = ret;
1110
1111 if (msg->status && ctlr->handle_err)
1112 ctlr->handle_err(ctlr, msg);
1113
1114 spi_res_release(ctlr, msg);
1115
1116 spi_finalize_current_message(ctlr);
1117
1118 return ret;
1119}
1120
1121/**
1122 * spi_finalize_current_transfer - report completion of a transfer
1123 * @ctlr: the controller reporting completion
1124 *
1125 * Called by SPI drivers using the core transfer_one_message()
1126 * implementation to notify it that the current interrupt driven
1127 * transfer has finished and the next one may be scheduled.
1128 */
1129void spi_finalize_current_transfer(struct spi_controller *ctlr)
1130{
1131 complete(&ctlr->xfer_completion);
1132}
1133EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1134
1135/**
1136 * __spi_pump_messages - function which processes spi message queue
1137 * @ctlr: controller to process queue for
1138 * @in_kthread: true if we are in the context of the message pump thread
1139 *
1140 * This function checks if there is any spi message in the queue that
1141 * needs processing and if so call out to the driver to initialize hardware
1142 * and transfer each message.
1143 *
1144 * Note that it is called both from the kthread itself and also from
1145 * inside spi_sync(); the queue extraction handling at the top of the
1146 * function should deal with this safely.
1147 */
1148static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1149{
1150 unsigned long flags;
1151 bool was_busy = false;
1152 int ret;
1153
1154 /* Lock queue */
1155 spin_lock_irqsave(&ctlr->queue_lock, flags);
1156
1157 /* Make sure we are not already running a message */
1158 if (ctlr->cur_msg) {
1159 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1160 return;
1161 }
1162
1163 /* If another context is idling the device then defer */
1164 if (ctlr->idling) {
1165 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1166 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1167 return;
1168 }
1169
1170 /* Check if the queue is idle */
1171 if (list_empty(&ctlr->queue) || !ctlr->running) {
1172 if (!ctlr->busy) {
1173 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1174 return;
1175 }
1176
1177 /* Only do teardown in the thread */
1178 if (!in_kthread) {
1179 kthread_queue_work(&ctlr->kworker,
1180 &ctlr->pump_messages);
1181 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1182 return;
1183 }
1184
1185 ctlr->busy = false;
1186 ctlr->idling = true;
1187 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1188
1189 kfree(ctlr->dummy_rx);
1190 ctlr->dummy_rx = NULL;
1191 kfree(ctlr->dummy_tx);
1192 ctlr->dummy_tx = NULL;
1193 if (ctlr->unprepare_transfer_hardware &&
1194 ctlr->unprepare_transfer_hardware(ctlr))
1195 dev_err(&ctlr->dev,
1196 "failed to unprepare transfer hardware\n");
1197 if (ctlr->auto_runtime_pm) {
1198 pm_runtime_mark_last_busy(ctlr->dev.parent);
1199 pm_runtime_put_autosuspend(ctlr->dev.parent);
1200 }
1201 trace_spi_controller_idle(ctlr);
1202
1203 spin_lock_irqsave(&ctlr->queue_lock, flags);
1204 ctlr->idling = false;
1205 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1206 return;
1207 }
1208
1209 /* Extract head of queue */
1210 ctlr->cur_msg =
1211 list_first_entry(&ctlr->queue, struct spi_message, queue);
1212
1213 list_del_init(&ctlr->cur_msg->queue);
1214 if (ctlr->busy)
1215 was_busy = true;
1216 else
1217 ctlr->busy = true;
1218 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1219
1220 mutex_lock(&ctlr->io_mutex);
1221
1222 if (!was_busy && ctlr->auto_runtime_pm) {
1223 ret = pm_runtime_get_sync(ctlr->dev.parent);
1224 if (ret < 0) {
1225 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1226 ret);
1227 mutex_unlock(&ctlr->io_mutex);
1228 return;
1229 }
1230 }
1231
1232 if (!was_busy)
1233 trace_spi_controller_busy(ctlr);
1234
1235 if (!was_busy && ctlr->prepare_transfer_hardware) {
1236 ret = ctlr->prepare_transfer_hardware(ctlr);
1237 if (ret) {
1238 dev_err(&ctlr->dev,
1239 "failed to prepare transfer hardware\n");
1240
1241 if (ctlr->auto_runtime_pm)
1242 pm_runtime_put(ctlr->dev.parent);
1243 mutex_unlock(&ctlr->io_mutex);
1244 return;
1245 }
1246 }
1247
1248 trace_spi_message_start(ctlr->cur_msg);
1249
1250 if (ctlr->prepare_message) {
1251 ret = ctlr->prepare_message(ctlr, ctlr->cur_msg);
1252 if (ret) {
1253 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1254 ret);
1255 ctlr->cur_msg->status = ret;
1256 spi_finalize_current_message(ctlr);
1257 goto out;
1258 }
1259 ctlr->cur_msg_prepared = true;
1260 }
1261
1262 ret = spi_map_msg(ctlr, ctlr->cur_msg);
1263 if (ret) {
1264 ctlr->cur_msg->status = ret;
1265 spi_finalize_current_message(ctlr);
1266 goto out;
1267 }
1268
1269 ret = ctlr->transfer_one_message(ctlr, ctlr->cur_msg);
1270 if (ret) {
1271 dev_err(&ctlr->dev,
1272 "failed to transfer one message from queue\n");
1273 goto out;
1274 }
1275
1276out:
1277 mutex_unlock(&ctlr->io_mutex);
1278
1279 /* Prod the scheduler in case transfer_one() was busy waiting */
1280 if (!ret)
1281 cond_resched();
1282}
1283
1284/**
1285 * spi_pump_messages - kthread work function which processes spi message queue
1286 * @work: pointer to kthread work struct contained in the controller struct
1287 */
1288static void spi_pump_messages(struct kthread_work *work)
1289{
1290 struct spi_controller *ctlr =
1291 container_of(work, struct spi_controller, pump_messages);
1292
1293 __spi_pump_messages(ctlr, true);
1294}
1295
1296static int spi_init_queue(struct spi_controller *ctlr)
1297{
1298 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1299
1300 ctlr->running = false;
1301 ctlr->busy = false;
1302
1303 kthread_init_worker(&ctlr->kworker);
1304 ctlr->kworker_task = kthread_run(kthread_worker_fn, &ctlr->kworker,
1305 "%s", dev_name(&ctlr->dev));
1306 if (IS_ERR(ctlr->kworker_task)) {
1307 dev_err(&ctlr->dev, "failed to create message pump task\n");
1308 return PTR_ERR(ctlr->kworker_task);
1309 }
1310 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1311
1312 /*
1313 * Controller config will indicate if this controller should run the
1314 * message pump with high (realtime) priority to reduce the transfer
1315 * latency on the bus by minimising the delay between a transfer
1316 * request and the scheduling of the message pump thread. Without this
1317 * setting the message pump thread will remain at default priority.
1318 */
1319 if (ctlr->rt) {
1320 dev_info(&ctlr->dev,
1321 "will run message pump with realtime priority\n");
1322 sched_setscheduler(ctlr->kworker_task, SCHED_FIFO, ¶m);
1323 }
1324
1325 return 0;
1326}
1327
1328/**
1329 * spi_get_next_queued_message() - called by driver to check for queued
1330 * messages
1331 * @ctlr: the controller to check for queued messages
1332 *
1333 * If there are more messages in the queue, the next message is returned from
1334 * this call.
1335 *
1336 * Return: the next message in the queue, else NULL if the queue is empty.
1337 */
1338struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1339{
1340 struct spi_message *next;
1341 unsigned long flags;
1342
1343 /* get a pointer to the next message, if any */
1344 spin_lock_irqsave(&ctlr->queue_lock, flags);
1345 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1346 queue);
1347 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1348
1349 return next;
1350}
1351EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1352
1353/**
1354 * spi_finalize_current_message() - the current message is complete
1355 * @ctlr: the controller to return the message to
1356 *
1357 * Called by the driver to notify the core that the message in the front of the
1358 * queue is complete and can be removed from the queue.
1359 */
1360void spi_finalize_current_message(struct spi_controller *ctlr)
1361{
1362 struct spi_message *mesg;
1363 unsigned long flags;
1364 int ret;
1365
1366 spin_lock_irqsave(&ctlr->queue_lock, flags);
1367 mesg = ctlr->cur_msg;
1368 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1369
1370 spi_unmap_msg(ctlr, mesg);
1371
1372 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1373 ret = ctlr->unprepare_message(ctlr, mesg);
1374 if (ret) {
1375 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1376 ret);
1377 }
1378 }
1379
1380 spin_lock_irqsave(&ctlr->queue_lock, flags);
1381 ctlr->cur_msg = NULL;
1382 ctlr->cur_msg_prepared = false;
1383 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1384 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1385
1386 trace_spi_message_done(mesg);
1387
1388 mesg->state = NULL;
1389 if (mesg->complete)
1390 mesg->complete(mesg->context);
1391}
1392EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1393
1394static int spi_start_queue(struct spi_controller *ctlr)
1395{
1396 unsigned long flags;
1397
1398 spin_lock_irqsave(&ctlr->queue_lock, flags);
1399
1400 if (ctlr->running || ctlr->busy) {
1401 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1402 return -EBUSY;
1403 }
1404
1405 ctlr->running = true;
1406 ctlr->cur_msg = NULL;
1407 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1408
1409 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1410
1411 return 0;
1412}
1413
1414static int spi_stop_queue(struct spi_controller *ctlr)
1415{
1416 unsigned long flags;
1417 unsigned limit = 500;
1418 int ret = 0;
1419
1420 spin_lock_irqsave(&ctlr->queue_lock, flags);
1421
1422 /*
1423 * This is a bit lame, but is optimized for the common execution path.
1424 * A wait_queue on the ctlr->busy could be used, but then the common
1425 * execution path (pump_messages) would be required to call wake_up or
1426 * friends on every SPI message. Do this instead.
1427 */
1428 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1429 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1430 usleep_range(10000, 11000);
1431 spin_lock_irqsave(&ctlr->queue_lock, flags);
1432 }
1433
1434 if (!list_empty(&ctlr->queue) || ctlr->busy)
1435 ret = -EBUSY;
1436 else
1437 ctlr->running = false;
1438
1439 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1440
1441 if (ret) {
1442 dev_warn(&ctlr->dev, "could not stop message queue\n");
1443 return ret;
1444 }
1445 return ret;
1446}
1447
1448static int spi_destroy_queue(struct spi_controller *ctlr)
1449{
1450 int ret;
1451
1452 ret = spi_stop_queue(ctlr);
1453
1454 /*
1455 * kthread_flush_worker will block until all work is done.
1456 * If the reason that stop_queue timed out is that the work will never
1457 * finish, then it does no good to call flush/stop thread, so
1458 * return anyway.
1459 */
1460 if (ret) {
1461 dev_err(&ctlr->dev, "problem destroying queue\n");
1462 return ret;
1463 }
1464
1465 kthread_flush_worker(&ctlr->kworker);
1466 kthread_stop(ctlr->kworker_task);
1467
1468 return 0;
1469}
1470
1471static int __spi_queued_transfer(struct spi_device *spi,
1472 struct spi_message *msg,
1473 bool need_pump)
1474{
1475 struct spi_controller *ctlr = spi->controller;
1476 unsigned long flags;
1477
1478 spin_lock_irqsave(&ctlr->queue_lock, flags);
1479
1480 if (!ctlr->running) {
1481 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1482 return -ESHUTDOWN;
1483 }
1484 msg->actual_length = 0;
1485 msg->status = -EINPROGRESS;
1486
1487 list_add_tail(&msg->queue, &ctlr->queue);
1488 if (!ctlr->busy && need_pump)
1489 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1490
1491 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1492 return 0;
1493}
1494
1495/**
1496 * spi_queued_transfer - transfer function for queued transfers
1497 * @spi: spi device which is requesting transfer
1498 * @msg: spi message which is to handled is queued to driver queue
1499 *
1500 * Return: zero on success, else a negative error code.
1501 */
1502static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1503{
1504 return __spi_queued_transfer(spi, msg, true);
1505}
1506
1507static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1508{
1509 int ret;
1510
1511 ctlr->transfer = spi_queued_transfer;
1512 if (!ctlr->transfer_one_message)
1513 ctlr->transfer_one_message = spi_transfer_one_message;
1514
1515 /* Initialize and start queue */
1516 ret = spi_init_queue(ctlr);
1517 if (ret) {
1518 dev_err(&ctlr->dev, "problem initializing queue\n");
1519 goto err_init_queue;
1520 }
1521 ctlr->queued = true;
1522 ret = spi_start_queue(ctlr);
1523 if (ret) {
1524 dev_err(&ctlr->dev, "problem starting queue\n");
1525 goto err_start_queue;
1526 }
1527
1528 return 0;
1529
1530err_start_queue:
1531 spi_destroy_queue(ctlr);
1532err_init_queue:
1533 return ret;
1534}
1535
1536/*-------------------------------------------------------------------------*/
1537
1538#if defined(CONFIG_OF)
1539static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1540 struct device_node *nc)
1541{
1542 u32 value;
1543 int rc;
1544
1545 /* Mode (clock phase/polarity/etc.) */
1546 if (of_property_read_bool(nc, "spi-cpha"))
1547 spi->mode |= SPI_CPHA;
1548 if (of_property_read_bool(nc, "spi-cpol"))
1549 spi->mode |= SPI_CPOL;
1550 if (of_property_read_bool(nc, "spi-cs-high"))
1551 spi->mode |= SPI_CS_HIGH;
1552 if (of_property_read_bool(nc, "spi-3wire"))
1553 spi->mode |= SPI_3WIRE;
1554 if (of_property_read_bool(nc, "spi-lsb-first"))
1555 spi->mode |= SPI_LSB_FIRST;
1556
1557 /* Device DUAL/QUAD mode */
1558 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1559 switch (value) {
1560 case 1:
1561 break;
1562 case 2:
1563 spi->mode |= SPI_TX_DUAL;
1564 break;
1565 case 4:
1566 spi->mode |= SPI_TX_QUAD;
1567 break;
1568 default:
1569 dev_warn(&ctlr->dev,
1570 "spi-tx-bus-width %d not supported\n",
1571 value);
1572 break;
1573 }
1574 }
1575
1576 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1577 switch (value) {
1578 case 1:
1579 break;
1580 case 2:
1581 spi->mode |= SPI_RX_DUAL;
1582 break;
1583 case 4:
1584 spi->mode |= SPI_RX_QUAD;
1585 break;
1586 default:
1587 dev_warn(&ctlr->dev,
1588 "spi-rx-bus-width %d not supported\n",
1589 value);
1590 break;
1591 }
1592 }
1593
1594 if (spi_controller_is_slave(ctlr)) {
1595 if (strcmp(nc->name, "slave")) {
1596 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
1597 nc);
1598 return -EINVAL;
1599 }
1600 return 0;
1601 }
1602
1603 /* Device address */
1604 rc = of_property_read_u32(nc, "reg", &value);
1605 if (rc) {
1606 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
1607 nc, rc);
1608 return rc;
1609 }
1610 spi->chip_select = value;
1611
1612 /* Device speed */
1613 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1614 if (rc) {
1615 dev_err(&ctlr->dev,
1616 "%pOF has no valid 'spi-max-frequency' property (%d)\n", nc, rc);
1617 return rc;
1618 }
1619 spi->max_speed_hz = value;
1620
1621 return 0;
1622}
1623
1624static struct spi_device *
1625of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
1626{
1627 struct spi_device *spi;
1628 int rc;
1629
1630 /* Alloc an spi_device */
1631 spi = spi_alloc_device(ctlr);
1632 if (!spi) {
1633 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
1634 rc = -ENOMEM;
1635 goto err_out;
1636 }
1637
1638 /* Select device driver */
1639 rc = of_modalias_node(nc, spi->modalias,
1640 sizeof(spi->modalias));
1641 if (rc < 0) {
1642 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
1643 goto err_out;
1644 }
1645
1646 rc = of_spi_parse_dt(ctlr, spi, nc);
1647 if (rc)
1648 goto err_out;
1649
1650 /* Store a pointer to the node in the device structure */
1651 of_node_get(nc);
1652 spi->dev.of_node = nc;
1653
1654 /* Register the new device */
1655 rc = spi_add_device(spi);
1656 if (rc) {
1657 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
1658 goto err_of_node_put;
1659 }
1660
1661 return spi;
1662
1663err_of_node_put:
1664 of_node_put(nc);
1665err_out:
1666 spi_dev_put(spi);
1667 return ERR_PTR(rc);
1668}
1669
1670/**
1671 * of_register_spi_devices() - Register child devices onto the SPI bus
1672 * @ctlr: Pointer to spi_controller device
1673 *
1674 * Registers an spi_device for each child node of controller node which
1675 * represents a valid SPI slave.
1676 */
1677static void of_register_spi_devices(struct spi_controller *ctlr)
1678{
1679 struct spi_device *spi;
1680 struct device_node *nc;
1681
1682 if (!ctlr->dev.of_node)
1683 return;
1684
1685 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
1686 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1687 continue;
1688 spi = of_register_spi_device(ctlr, nc);
1689 if (IS_ERR(spi)) {
1690 dev_warn(&ctlr->dev,
1691 "Failed to create SPI device for %pOF\n", nc);
1692 of_node_clear_flag(nc, OF_POPULATED);
1693 }
1694 }
1695}
1696#else
1697static void of_register_spi_devices(struct spi_controller *ctlr) { }
1698#endif
1699
1700#ifdef CONFIG_ACPI
1701static void acpi_spi_parse_apple_properties(struct spi_device *spi)
1702{
1703 struct acpi_device *dev = ACPI_COMPANION(&spi->dev);
1704 const union acpi_object *obj;
1705
1706 if (!x86_apple_machine)
1707 return;
1708
1709 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
1710 && obj->buffer.length >= 4)
1711 spi->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
1712
1713 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
1714 && obj->buffer.length == 8)
1715 spi->bits_per_word = *(u64 *)obj->buffer.pointer;
1716
1717 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
1718 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
1719 spi->mode |= SPI_LSB_FIRST;
1720
1721 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
1722 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
1723 spi->mode |= SPI_CPOL;
1724
1725 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
1726 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
1727 spi->mode |= SPI_CPHA;
1728}
1729
1730static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1731{
1732 struct spi_device *spi = data;
1733 struct spi_controller *ctlr = spi->controller;
1734
1735 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1736 struct acpi_resource_spi_serialbus *sb;
1737
1738 sb = &ares->data.spi_serial_bus;
1739 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1740 /*
1741 * ACPI DeviceSelection numbering is handled by the
1742 * host controller driver in Windows and can vary
1743 * from driver to driver. In Linux we always expect
1744 * 0 .. max - 1 so we need to ask the driver to
1745 * translate between the two schemes.
1746 */
1747 if (ctlr->fw_translate_cs) {
1748 int cs = ctlr->fw_translate_cs(ctlr,
1749 sb->device_selection);
1750 if (cs < 0)
1751 return cs;
1752 spi->chip_select = cs;
1753 } else {
1754 spi->chip_select = sb->device_selection;
1755 }
1756
1757 spi->max_speed_hz = sb->connection_speed;
1758
1759 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1760 spi->mode |= SPI_CPHA;
1761 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1762 spi->mode |= SPI_CPOL;
1763 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1764 spi->mode |= SPI_CS_HIGH;
1765 }
1766 } else if (spi->irq < 0) {
1767 struct resource r;
1768
1769 if (acpi_dev_resource_interrupt(ares, 0, &r))
1770 spi->irq = r.start;
1771 }
1772
1773 /* Always tell the ACPI core to skip this resource */
1774 return 1;
1775}
1776
1777static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
1778 struct acpi_device *adev)
1779{
1780 struct list_head resource_list;
1781 struct spi_device *spi;
1782 int ret;
1783
1784 if (acpi_bus_get_status(adev) || !adev->status.present ||
1785 acpi_device_enumerated(adev))
1786 return AE_OK;
1787
1788 spi = spi_alloc_device(ctlr);
1789 if (!spi) {
1790 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
1791 dev_name(&adev->dev));
1792 return AE_NO_MEMORY;
1793 }
1794
1795 ACPI_COMPANION_SET(&spi->dev, adev);
1796 spi->irq = -1;
1797
1798 INIT_LIST_HEAD(&resource_list);
1799 ret = acpi_dev_get_resources(adev, &resource_list,
1800 acpi_spi_add_resource, spi);
1801 acpi_dev_free_resource_list(&resource_list);
1802
1803 acpi_spi_parse_apple_properties(spi);
1804
1805 if (ret < 0 || !spi->max_speed_hz) {
1806 spi_dev_put(spi);
1807 return AE_OK;
1808 }
1809
1810 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
1811 sizeof(spi->modalias));
1812
1813 if (spi->irq < 0)
1814 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1815
1816 acpi_device_set_enumerated(adev);
1817
1818 adev->power.flags.ignore_parent = true;
1819 if (spi_add_device(spi)) {
1820 adev->power.flags.ignore_parent = false;
1821 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
1822 dev_name(&adev->dev));
1823 spi_dev_put(spi);
1824 }
1825
1826 return AE_OK;
1827}
1828
1829static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1830 void *data, void **return_value)
1831{
1832 struct spi_controller *ctlr = data;
1833 struct acpi_device *adev;
1834
1835 if (acpi_bus_get_device(handle, &adev))
1836 return AE_OK;
1837
1838 return acpi_register_spi_device(ctlr, adev);
1839}
1840
1841static void acpi_register_spi_devices(struct spi_controller *ctlr)
1842{
1843 acpi_status status;
1844 acpi_handle handle;
1845
1846 handle = ACPI_HANDLE(ctlr->dev.parent);
1847 if (!handle)
1848 return;
1849
1850 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1851 acpi_spi_add_device, NULL, ctlr, NULL);
1852 if (ACPI_FAILURE(status))
1853 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
1854}
1855#else
1856static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
1857#endif /* CONFIG_ACPI */
1858
1859static void spi_controller_release(struct device *dev)
1860{
1861 struct spi_controller *ctlr;
1862
1863 ctlr = container_of(dev, struct spi_controller, dev);
1864 kfree(ctlr);
1865}
1866
1867static struct class spi_master_class = {
1868 .name = "spi_master",
1869 .owner = THIS_MODULE,
1870 .dev_release = spi_controller_release,
1871 .dev_groups = spi_master_groups,
1872};
1873
1874#ifdef CONFIG_SPI_SLAVE
1875/**
1876 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
1877 * controller
1878 * @spi: device used for the current transfer
1879 */
1880int spi_slave_abort(struct spi_device *spi)
1881{
1882 struct spi_controller *ctlr = spi->controller;
1883
1884 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
1885 return ctlr->slave_abort(ctlr);
1886
1887 return -ENOTSUPP;
1888}
1889EXPORT_SYMBOL_GPL(spi_slave_abort);
1890
1891static int match_true(struct device *dev, void *data)
1892{
1893 return 1;
1894}
1895
1896static ssize_t spi_slave_show(struct device *dev,
1897 struct device_attribute *attr, char *buf)
1898{
1899 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
1900 dev);
1901 struct device *child;
1902
1903 child = device_find_child(&ctlr->dev, NULL, match_true);
1904 return sprintf(buf, "%s\n",
1905 child ? to_spi_device(child)->modalias : NULL);
1906}
1907
1908static ssize_t spi_slave_store(struct device *dev,
1909 struct device_attribute *attr, const char *buf,
1910 size_t count)
1911{
1912 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
1913 dev);
1914 struct spi_device *spi;
1915 struct device *child;
1916 char name[32];
1917 int rc;
1918
1919 rc = sscanf(buf, "%31s", name);
1920 if (rc != 1 || !name[0])
1921 return -EINVAL;
1922
1923 child = device_find_child(&ctlr->dev, NULL, match_true);
1924 if (child) {
1925 /* Remove registered slave */
1926 device_unregister(child);
1927 put_device(child);
1928 }
1929
1930 if (strcmp(name, "(null)")) {
1931 /* Register new slave */
1932 spi = spi_alloc_device(ctlr);
1933 if (!spi)
1934 return -ENOMEM;
1935
1936 strlcpy(spi->modalias, name, sizeof(spi->modalias));
1937
1938 rc = spi_add_device(spi);
1939 if (rc) {
1940 spi_dev_put(spi);
1941 return rc;
1942 }
1943 }
1944
1945 return count;
1946}
1947
1948static DEVICE_ATTR(slave, 0644, spi_slave_show, spi_slave_store);
1949
1950static struct attribute *spi_slave_attrs[] = {
1951 &dev_attr_slave.attr,
1952 NULL,
1953};
1954
1955static const struct attribute_group spi_slave_group = {
1956 .attrs = spi_slave_attrs,
1957};
1958
1959static const struct attribute_group *spi_slave_groups[] = {
1960 &spi_controller_statistics_group,
1961 &spi_slave_group,
1962 NULL,
1963};
1964
1965static struct class spi_slave_class = {
1966 .name = "spi_slave",
1967 .owner = THIS_MODULE,
1968 .dev_release = spi_controller_release,
1969 .dev_groups = spi_slave_groups,
1970};
1971#else
1972extern struct class spi_slave_class; /* dummy */
1973#endif
1974
1975/**
1976 * __spi_alloc_controller - allocate an SPI master or slave controller
1977 * @dev: the controller, possibly using the platform_bus
1978 * @size: how much zeroed driver-private data to allocate; the pointer to this
1979 * memory is in the driver_data field of the returned device,
1980 * accessible with spi_controller_get_devdata().
1981 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
1982 * slave (true) controller
1983 * Context: can sleep
1984 *
1985 * This call is used only by SPI controller drivers, which are the
1986 * only ones directly touching chip registers. It's how they allocate
1987 * an spi_controller structure, prior to calling spi_register_controller().
1988 *
1989 * This must be called from context that can sleep.
1990 *
1991 * The caller is responsible for assigning the bus number and initializing the
1992 * controller's methods before calling spi_register_controller(); and (after
1993 * errors adding the device) calling spi_controller_put() to prevent a memory
1994 * leak.
1995 *
1996 * Return: the SPI controller structure on success, else NULL.
1997 */
1998struct spi_controller *__spi_alloc_controller(struct device *dev,
1999 unsigned int size, bool slave)
2000{
2001 struct spi_controller *ctlr;
2002
2003 if (!dev)
2004 return NULL;
2005
2006 ctlr = kzalloc(size + sizeof(*ctlr), GFP_KERNEL);
2007 if (!ctlr)
2008 return NULL;
2009
2010 device_initialize(&ctlr->dev);
2011 ctlr->bus_num = -1;
2012 ctlr->num_chipselect = 1;
2013 ctlr->slave = slave;
2014 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2015 ctlr->dev.class = &spi_slave_class;
2016 else
2017 ctlr->dev.class = &spi_master_class;
2018 ctlr->dev.parent = dev;
2019 pm_suspend_ignore_children(&ctlr->dev, true);
2020 spi_controller_set_devdata(ctlr, &ctlr[1]);
2021
2022 return ctlr;
2023}
2024EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2025
2026#ifdef CONFIG_OF
2027static int of_spi_register_master(struct spi_controller *ctlr)
2028{
2029 int nb, i, *cs;
2030 struct device_node *np = ctlr->dev.of_node;
2031
2032 if (!np)
2033 return 0;
2034
2035 nb = of_gpio_named_count(np, "cs-gpios");
2036 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2037
2038 /* Return error only for an incorrectly formed cs-gpios property */
2039 if (nb == 0 || nb == -ENOENT)
2040 return 0;
2041 else if (nb < 0)
2042 return nb;
2043
2044 cs = devm_kzalloc(&ctlr->dev, sizeof(int) * ctlr->num_chipselect,
2045 GFP_KERNEL);
2046 ctlr->cs_gpios = cs;
2047
2048 if (!ctlr->cs_gpios)
2049 return -ENOMEM;
2050
2051 for (i = 0; i < ctlr->num_chipselect; i++)
2052 cs[i] = -ENOENT;
2053
2054 for (i = 0; i < nb; i++)
2055 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2056
2057 return 0;
2058}
2059#else
2060static int of_spi_register_master(struct spi_controller *ctlr)
2061{
2062 return 0;
2063}
2064#endif
2065
2066/**
2067 * spi_register_controller - register SPI master or slave controller
2068 * @ctlr: initialized master, originally from spi_alloc_master() or
2069 * spi_alloc_slave()
2070 * Context: can sleep
2071 *
2072 * SPI controllers connect to their drivers using some non-SPI bus,
2073 * such as the platform bus. The final stage of probe() in that code
2074 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2075 *
2076 * SPI controllers use board specific (often SOC specific) bus numbers,
2077 * and board-specific addressing for SPI devices combines those numbers
2078 * with chip select numbers. Since SPI does not directly support dynamic
2079 * device identification, boards need configuration tables telling which
2080 * chip is at which address.
2081 *
2082 * This must be called from context that can sleep. It returns zero on
2083 * success, else a negative error code (dropping the controller's refcount).
2084 * After a successful return, the caller is responsible for calling
2085 * spi_unregister_controller().
2086 *
2087 * Return: zero on success, else a negative error code.
2088 */
2089int spi_register_controller(struct spi_controller *ctlr)
2090{
2091 struct device *dev = ctlr->dev.parent;
2092 struct boardinfo *bi;
2093 int status = -ENODEV;
2094 int id, first_dynamic;
2095
2096 if (!dev)
2097 return -ENODEV;
2098
2099 if (!spi_controller_is_slave(ctlr)) {
2100 status = of_spi_register_master(ctlr);
2101 if (status)
2102 return status;
2103 }
2104
2105 /* even if it's just one always-selected device, there must
2106 * be at least one chipselect
2107 */
2108 if (ctlr->num_chipselect == 0)
2109 return -EINVAL;
2110 /* allocate dynamic bus number using Linux idr */
2111 if ((ctlr->bus_num < 0) && ctlr->dev.of_node) {
2112 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2113 if (id >= 0) {
2114 ctlr->bus_num = id;
2115 mutex_lock(&board_lock);
2116 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2117 ctlr->bus_num + 1, GFP_KERNEL);
2118 mutex_unlock(&board_lock);
2119 if (WARN(id < 0, "couldn't get idr"))
2120 return id == -ENOSPC ? -EBUSY : id;
2121 }
2122 }
2123 if (ctlr->bus_num < 0) {
2124 first_dynamic = of_alias_get_highest_id("spi");
2125 if (first_dynamic < 0)
2126 first_dynamic = 0;
2127 else
2128 first_dynamic++;
2129
2130 mutex_lock(&board_lock);
2131 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2132 0, GFP_KERNEL);
2133 mutex_unlock(&board_lock);
2134 if (WARN(id < 0, "couldn't get idr"))
2135 return id;
2136 ctlr->bus_num = id;
2137 }
2138 INIT_LIST_HEAD(&ctlr->queue);
2139 spin_lock_init(&ctlr->queue_lock);
2140 spin_lock_init(&ctlr->bus_lock_spinlock);
2141 mutex_init(&ctlr->bus_lock_mutex);
2142 mutex_init(&ctlr->io_mutex);
2143 ctlr->bus_lock_flag = 0;
2144 init_completion(&ctlr->xfer_completion);
2145 if (!ctlr->max_dma_len)
2146 ctlr->max_dma_len = INT_MAX;
2147
2148 /* register the device, then userspace will see it.
2149 * registration fails if the bus ID is in use.
2150 */
2151 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2152 status = device_add(&ctlr->dev);
2153 if (status < 0) {
2154 /* free bus id */
2155 mutex_lock(&board_lock);
2156 idr_remove(&spi_master_idr, ctlr->bus_num);
2157 mutex_unlock(&board_lock);
2158 goto done;
2159 }
2160 dev_dbg(dev, "registered %s %s\n",
2161 spi_controller_is_slave(ctlr) ? "slave" : "master",
2162 dev_name(&ctlr->dev));
2163
2164 /* If we're using a queued driver, start the queue */
2165 if (ctlr->transfer)
2166 dev_info(dev, "controller is unqueued, this is deprecated\n");
2167 else {
2168 status = spi_controller_initialize_queue(ctlr);
2169 if (status) {
2170 device_del(&ctlr->dev);
2171 /* free bus id */
2172 mutex_lock(&board_lock);
2173 idr_remove(&spi_master_idr, ctlr->bus_num);
2174 mutex_unlock(&board_lock);
2175 goto done;
2176 }
2177 }
2178 /* add statistics */
2179 spin_lock_init(&ctlr->statistics.lock);
2180
2181 mutex_lock(&board_lock);
2182 list_add_tail(&ctlr->list, &spi_controller_list);
2183 list_for_each_entry(bi, &board_list, list)
2184 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2185 mutex_unlock(&board_lock);
2186
2187 /* Register devices from the device tree and ACPI */
2188 of_register_spi_devices(ctlr);
2189 acpi_register_spi_devices(ctlr);
2190done:
2191 return status;
2192}
2193EXPORT_SYMBOL_GPL(spi_register_controller);
2194
2195static void devm_spi_unregister(struct device *dev, void *res)
2196{
2197 spi_unregister_controller(*(struct spi_controller **)res);
2198}
2199
2200/**
2201 * devm_spi_register_controller - register managed SPI master or slave
2202 * controller
2203 * @dev: device managing SPI controller
2204 * @ctlr: initialized controller, originally from spi_alloc_master() or
2205 * spi_alloc_slave()
2206 * Context: can sleep
2207 *
2208 * Register a SPI device as with spi_register_controller() which will
2209 * automatically be unregistered and freed.
2210 *
2211 * Return: zero on success, else a negative error code.
2212 */
2213int devm_spi_register_controller(struct device *dev,
2214 struct spi_controller *ctlr)
2215{
2216 struct spi_controller **ptr;
2217 int ret;
2218
2219 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2220 if (!ptr)
2221 return -ENOMEM;
2222
2223 ret = spi_register_controller(ctlr);
2224 if (!ret) {
2225 *ptr = ctlr;
2226 devres_add(dev, ptr);
2227 } else {
2228 devres_free(ptr);
2229 }
2230
2231 return ret;
2232}
2233EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2234
2235static int __unregister(struct device *dev, void *null)
2236{
2237 spi_unregister_device(to_spi_device(dev));
2238 return 0;
2239}
2240
2241/**
2242 * spi_unregister_controller - unregister SPI master or slave controller
2243 * @ctlr: the controller being unregistered
2244 * Context: can sleep
2245 *
2246 * This call is used only by SPI controller drivers, which are the
2247 * only ones directly touching chip registers.
2248 *
2249 * This must be called from context that can sleep.
2250 *
2251 * Note that this function also drops a reference to the controller.
2252 */
2253void spi_unregister_controller(struct spi_controller *ctlr)
2254{
2255 struct spi_controller *found;
2256 int id = ctlr->bus_num;
2257 int dummy;
2258
2259 /* First make sure that this controller was ever added */
2260 mutex_lock(&board_lock);
2261 found = idr_find(&spi_master_idr, id);
2262 mutex_unlock(&board_lock);
2263 if (ctlr->queued) {
2264 if (spi_destroy_queue(ctlr))
2265 dev_err(&ctlr->dev, "queue remove failed\n");
2266 }
2267 mutex_lock(&board_lock);
2268 list_del(&ctlr->list);
2269 mutex_unlock(&board_lock);
2270
2271 dummy = device_for_each_child(&ctlr->dev, NULL, __unregister);
2272 device_unregister(&ctlr->dev);
2273 /* free bus id */
2274 mutex_lock(&board_lock);
2275 if (found == ctlr)
2276 idr_remove(&spi_master_idr, id);
2277 mutex_unlock(&board_lock);
2278}
2279EXPORT_SYMBOL_GPL(spi_unregister_controller);
2280
2281int spi_controller_suspend(struct spi_controller *ctlr)
2282{
2283 int ret;
2284
2285 /* Basically no-ops for non-queued controllers */
2286 if (!ctlr->queued)
2287 return 0;
2288
2289 ret = spi_stop_queue(ctlr);
2290 if (ret)
2291 dev_err(&ctlr->dev, "queue stop failed\n");
2292
2293 return ret;
2294}
2295EXPORT_SYMBOL_GPL(spi_controller_suspend);
2296
2297int spi_controller_resume(struct spi_controller *ctlr)
2298{
2299 int ret;
2300
2301 if (!ctlr->queued)
2302 return 0;
2303
2304 ret = spi_start_queue(ctlr);
2305 if (ret)
2306 dev_err(&ctlr->dev, "queue restart failed\n");
2307
2308 return ret;
2309}
2310EXPORT_SYMBOL_GPL(spi_controller_resume);
2311
2312static int __spi_controller_match(struct device *dev, const void *data)
2313{
2314 struct spi_controller *ctlr;
2315 const u16 *bus_num = data;
2316
2317 ctlr = container_of(dev, struct spi_controller, dev);
2318 return ctlr->bus_num == *bus_num;
2319}
2320
2321/**
2322 * spi_busnum_to_master - look up master associated with bus_num
2323 * @bus_num: the master's bus number
2324 * Context: can sleep
2325 *
2326 * This call may be used with devices that are registered after
2327 * arch init time. It returns a refcounted pointer to the relevant
2328 * spi_controller (which the caller must release), or NULL if there is
2329 * no such master registered.
2330 *
2331 * Return: the SPI master structure on success, else NULL.
2332 */
2333struct spi_controller *spi_busnum_to_master(u16 bus_num)
2334{
2335 struct device *dev;
2336 struct spi_controller *ctlr = NULL;
2337
2338 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2339 __spi_controller_match);
2340 if (dev)
2341 ctlr = container_of(dev, struct spi_controller, dev);
2342 /* reference got in class_find_device */
2343 return ctlr;
2344}
2345EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2346
2347/*-------------------------------------------------------------------------*/
2348
2349/* Core methods for SPI resource management */
2350
2351/**
2352 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2353 * during the processing of a spi_message while using
2354 * spi_transfer_one
2355 * @spi: the spi device for which we allocate memory
2356 * @release: the release code to execute for this resource
2357 * @size: size to alloc and return
2358 * @gfp: GFP allocation flags
2359 *
2360 * Return: the pointer to the allocated data
2361 *
2362 * This may get enhanced in the future to allocate from a memory pool
2363 * of the @spi_device or @spi_controller to avoid repeated allocations.
2364 */
2365void *spi_res_alloc(struct spi_device *spi,
2366 spi_res_release_t release,
2367 size_t size, gfp_t gfp)
2368{
2369 struct spi_res *sres;
2370
2371 sres = kzalloc(sizeof(*sres) + size, gfp);
2372 if (!sres)
2373 return NULL;
2374
2375 INIT_LIST_HEAD(&sres->entry);
2376 sres->release = release;
2377
2378 return sres->data;
2379}
2380EXPORT_SYMBOL_GPL(spi_res_alloc);
2381
2382/**
2383 * spi_res_free - free an spi resource
2384 * @res: pointer to the custom data of a resource
2385 *
2386 */
2387void spi_res_free(void *res)
2388{
2389 struct spi_res *sres = container_of(res, struct spi_res, data);
2390
2391 if (!res)
2392 return;
2393
2394 WARN_ON(!list_empty(&sres->entry));
2395 kfree(sres);
2396}
2397EXPORT_SYMBOL_GPL(spi_res_free);
2398
2399/**
2400 * spi_res_add - add a spi_res to the spi_message
2401 * @message: the spi message
2402 * @res: the spi_resource
2403 */
2404void spi_res_add(struct spi_message *message, void *res)
2405{
2406 struct spi_res *sres = container_of(res, struct spi_res, data);
2407
2408 WARN_ON(!list_empty(&sres->entry));
2409 list_add_tail(&sres->entry, &message->resources);
2410}
2411EXPORT_SYMBOL_GPL(spi_res_add);
2412
2413/**
2414 * spi_res_release - release all spi resources for this message
2415 * @ctlr: the @spi_controller
2416 * @message: the @spi_message
2417 */
2418void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
2419{
2420 struct spi_res *res;
2421
2422 while (!list_empty(&message->resources)) {
2423 res = list_last_entry(&message->resources,
2424 struct spi_res, entry);
2425
2426 if (res->release)
2427 res->release(ctlr, message, res->data);
2428
2429 list_del(&res->entry);
2430
2431 kfree(res);
2432 }
2433}
2434EXPORT_SYMBOL_GPL(spi_res_release);
2435
2436/*-------------------------------------------------------------------------*/
2437
2438/* Core methods for spi_message alterations */
2439
2440static void __spi_replace_transfers_release(struct spi_controller *ctlr,
2441 struct spi_message *msg,
2442 void *res)
2443{
2444 struct spi_replaced_transfers *rxfer = res;
2445 size_t i;
2446
2447 /* call extra callback if requested */
2448 if (rxfer->release)
2449 rxfer->release(ctlr, msg, res);
2450
2451 /* insert replaced transfers back into the message */
2452 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2453
2454 /* remove the formerly inserted entries */
2455 for (i = 0; i < rxfer->inserted; i++)
2456 list_del(&rxfer->inserted_transfers[i].transfer_list);
2457}
2458
2459/**
2460 * spi_replace_transfers - replace transfers with several transfers
2461 * and register change with spi_message.resources
2462 * @msg: the spi_message we work upon
2463 * @xfer_first: the first spi_transfer we want to replace
2464 * @remove: number of transfers to remove
2465 * @insert: the number of transfers we want to insert instead
2466 * @release: extra release code necessary in some circumstances
2467 * @extradatasize: extra data to allocate (with alignment guarantees
2468 * of struct @spi_transfer)
2469 * @gfp: gfp flags
2470 *
2471 * Returns: pointer to @spi_replaced_transfers,
2472 * PTR_ERR(...) in case of errors.
2473 */
2474struct spi_replaced_transfers *spi_replace_transfers(
2475 struct spi_message *msg,
2476 struct spi_transfer *xfer_first,
2477 size_t remove,
2478 size_t insert,
2479 spi_replaced_release_t release,
2480 size_t extradatasize,
2481 gfp_t gfp)
2482{
2483 struct spi_replaced_transfers *rxfer;
2484 struct spi_transfer *xfer;
2485 size_t i;
2486
2487 /* allocate the structure using spi_res */
2488 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2489 insert * sizeof(struct spi_transfer)
2490 + sizeof(struct spi_replaced_transfers)
2491 + extradatasize,
2492 gfp);
2493 if (!rxfer)
2494 return ERR_PTR(-ENOMEM);
2495
2496 /* the release code to invoke before running the generic release */
2497 rxfer->release = release;
2498
2499 /* assign extradata */
2500 if (extradatasize)
2501 rxfer->extradata =
2502 &rxfer->inserted_transfers[insert];
2503
2504 /* init the replaced_transfers list */
2505 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2506
2507 /* assign the list_entry after which we should reinsert
2508 * the @replaced_transfers - it may be spi_message.messages!
2509 */
2510 rxfer->replaced_after = xfer_first->transfer_list.prev;
2511
2512 /* remove the requested number of transfers */
2513 for (i = 0; i < remove; i++) {
2514 /* if the entry after replaced_after it is msg->transfers
2515 * then we have been requested to remove more transfers
2516 * than are in the list
2517 */
2518 if (rxfer->replaced_after->next == &msg->transfers) {
2519 dev_err(&msg->spi->dev,
2520 "requested to remove more spi_transfers than are available\n");
2521 /* insert replaced transfers back into the message */
2522 list_splice(&rxfer->replaced_transfers,
2523 rxfer->replaced_after);
2524
2525 /* free the spi_replace_transfer structure */
2526 spi_res_free(rxfer);
2527
2528 /* and return with an error */
2529 return ERR_PTR(-EINVAL);
2530 }
2531
2532 /* remove the entry after replaced_after from list of
2533 * transfers and add it to list of replaced_transfers
2534 */
2535 list_move_tail(rxfer->replaced_after->next,
2536 &rxfer->replaced_transfers);
2537 }
2538
2539 /* create copy of the given xfer with identical settings
2540 * based on the first transfer to get removed
2541 */
2542 for (i = 0; i < insert; i++) {
2543 /* we need to run in reverse order */
2544 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2545
2546 /* copy all spi_transfer data */
2547 memcpy(xfer, xfer_first, sizeof(*xfer));
2548
2549 /* add to list */
2550 list_add(&xfer->transfer_list, rxfer->replaced_after);
2551
2552 /* clear cs_change and delay_usecs for all but the last */
2553 if (i) {
2554 xfer->cs_change = false;
2555 xfer->delay_usecs = 0;
2556 }
2557 }
2558
2559 /* set up inserted */
2560 rxfer->inserted = insert;
2561
2562 /* and register it with spi_res/spi_message */
2563 spi_res_add(msg, rxfer);
2564
2565 return rxfer;
2566}
2567EXPORT_SYMBOL_GPL(spi_replace_transfers);
2568
2569static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
2570 struct spi_message *msg,
2571 struct spi_transfer **xferp,
2572 size_t maxsize,
2573 gfp_t gfp)
2574{
2575 struct spi_transfer *xfer = *xferp, *xfers;
2576 struct spi_replaced_transfers *srt;
2577 size_t offset;
2578 size_t count, i;
2579
2580 /* warn once about this fact that we are splitting a transfer */
2581 dev_warn_once(&msg->spi->dev,
2582 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2583 xfer->len, maxsize);
2584
2585 /* calculate how many we have to replace */
2586 count = DIV_ROUND_UP(xfer->len, maxsize);
2587
2588 /* create replacement */
2589 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
2590 if (IS_ERR(srt))
2591 return PTR_ERR(srt);
2592 xfers = srt->inserted_transfers;
2593
2594 /* now handle each of those newly inserted spi_transfers
2595 * note that the replacements spi_transfers all are preset
2596 * to the same values as *xferp, so tx_buf, rx_buf and len
2597 * are all identical (as well as most others)
2598 * so we just have to fix up len and the pointers.
2599 *
2600 * this also includes support for the depreciated
2601 * spi_message.is_dma_mapped interface
2602 */
2603
2604 /* the first transfer just needs the length modified, so we
2605 * run it outside the loop
2606 */
2607 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
2608
2609 /* all the others need rx_buf/tx_buf also set */
2610 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2611 /* update rx_buf, tx_buf and dma */
2612 if (xfers[i].rx_buf)
2613 xfers[i].rx_buf += offset;
2614 if (xfers[i].rx_dma)
2615 xfers[i].rx_dma += offset;
2616 if (xfers[i].tx_buf)
2617 xfers[i].tx_buf += offset;
2618 if (xfers[i].tx_dma)
2619 xfers[i].tx_dma += offset;
2620
2621 /* update length */
2622 xfers[i].len = min(maxsize, xfers[i].len - offset);
2623 }
2624
2625 /* we set up xferp to the last entry we have inserted,
2626 * so that we skip those already split transfers
2627 */
2628 *xferp = &xfers[count - 1];
2629
2630 /* increment statistics counters */
2631 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
2632 transfers_split_maxsize);
2633 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2634 transfers_split_maxsize);
2635
2636 return 0;
2637}
2638
2639/**
2640 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2641 * when an individual transfer exceeds a
2642 * certain size
2643 * @ctlr: the @spi_controller for this transfer
2644 * @msg: the @spi_message to transform
2645 * @maxsize: the maximum when to apply this
2646 * @gfp: GFP allocation flags
2647 *
2648 * Return: status of transformation
2649 */
2650int spi_split_transfers_maxsize(struct spi_controller *ctlr,
2651 struct spi_message *msg,
2652 size_t maxsize,
2653 gfp_t gfp)
2654{
2655 struct spi_transfer *xfer;
2656 int ret;
2657
2658 /* iterate over the transfer_list,
2659 * but note that xfer is advanced to the last transfer inserted
2660 * to avoid checking sizes again unnecessarily (also xfer does
2661 * potentiall belong to a different list by the time the
2662 * replacement has happened
2663 */
2664 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2665 if (xfer->len > maxsize) {
2666 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
2667 maxsize, gfp);
2668 if (ret)
2669 return ret;
2670 }
2671 }
2672
2673 return 0;
2674}
2675EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2676
2677/*-------------------------------------------------------------------------*/
2678
2679/* Core methods for SPI controller protocol drivers. Some of the
2680 * other core methods are currently defined as inline functions.
2681 */
2682
2683static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
2684 u8 bits_per_word)
2685{
2686 if (ctlr->bits_per_word_mask) {
2687 /* Only 32 bits fit in the mask */
2688 if (bits_per_word > 32)
2689 return -EINVAL;
2690 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
2691 return -EINVAL;
2692 }
2693
2694 return 0;
2695}
2696
2697/**
2698 * spi_setup - setup SPI mode and clock rate
2699 * @spi: the device whose settings are being modified
2700 * Context: can sleep, and no requests are queued to the device
2701 *
2702 * SPI protocol drivers may need to update the transfer mode if the
2703 * device doesn't work with its default. They may likewise need
2704 * to update clock rates or word sizes from initial values. This function
2705 * changes those settings, and must be called from a context that can sleep.
2706 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2707 * effect the next time the device is selected and data is transferred to
2708 * or from it. When this function returns, the spi device is deselected.
2709 *
2710 * Note that this call will fail if the protocol driver specifies an option
2711 * that the underlying controller or its driver does not support. For
2712 * example, not all hardware supports wire transfers using nine bit words,
2713 * LSB-first wire encoding, or active-high chipselects.
2714 *
2715 * Return: zero on success, else a negative error code.
2716 */
2717int spi_setup(struct spi_device *spi)
2718{
2719 unsigned bad_bits, ugly_bits;
2720 int status;
2721
2722 /* check mode to prevent that DUAL and QUAD set at the same time
2723 */
2724 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2725 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2726 dev_err(&spi->dev,
2727 "setup: can not select dual and quad at the same time\n");
2728 return -EINVAL;
2729 }
2730 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2731 */
2732 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2733 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2734 return -EINVAL;
2735 /* help drivers fail *cleanly* when they need options
2736 * that aren't supported with their current controller
2737 */
2738 bad_bits = spi->mode & ~spi->controller->mode_bits;
2739 ugly_bits = bad_bits &
2740 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2741 if (ugly_bits) {
2742 dev_warn(&spi->dev,
2743 "setup: ignoring unsupported mode bits %x\n",
2744 ugly_bits);
2745 spi->mode &= ~ugly_bits;
2746 bad_bits &= ~ugly_bits;
2747 }
2748 if (bad_bits) {
2749 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
2750 bad_bits);
2751 return -EINVAL;
2752 }
2753
2754 if (!spi->bits_per_word)
2755 spi->bits_per_word = 8;
2756
2757 status = __spi_validate_bits_per_word(spi->controller,
2758 spi->bits_per_word);
2759 if (status)
2760 return status;
2761
2762 if (!spi->max_speed_hz)
2763 spi->max_speed_hz = spi->controller->max_speed_hz;
2764
2765 if (spi->controller->setup)
2766 status = spi->controller->setup(spi);
2767
2768 spi_set_cs(spi, false);
2769
2770 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2771 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2772 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2773 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2774 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2775 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2776 spi->bits_per_word, spi->max_speed_hz,
2777 status);
2778
2779 return status;
2780}
2781EXPORT_SYMBOL_GPL(spi_setup);
2782
2783static int __spi_validate(struct spi_device *spi, struct spi_message *message)
2784{
2785 struct spi_controller *ctlr = spi->controller;
2786 struct spi_transfer *xfer;
2787 int w_size;
2788
2789 if (list_empty(&message->transfers))
2790 return -EINVAL;
2791
2792 /* Half-duplex links include original MicroWire, and ones with
2793 * only one data pin like SPI_3WIRE (switches direction) or where
2794 * either MOSI or MISO is missing. They can also be caused by
2795 * software limitations.
2796 */
2797 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
2798 (spi->mode & SPI_3WIRE)) {
2799 unsigned flags = ctlr->flags;
2800
2801 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2802 if (xfer->rx_buf && xfer->tx_buf)
2803 return -EINVAL;
2804 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
2805 return -EINVAL;
2806 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
2807 return -EINVAL;
2808 }
2809 }
2810
2811 /**
2812 * Set transfer bits_per_word and max speed as spi device default if
2813 * it is not set for this transfer.
2814 * Set transfer tx_nbits and rx_nbits as single transfer default
2815 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2816 */
2817 message->frame_length = 0;
2818 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2819 message->frame_length += xfer->len;
2820 if (!xfer->bits_per_word)
2821 xfer->bits_per_word = spi->bits_per_word;
2822
2823 if (!xfer->speed_hz)
2824 xfer->speed_hz = spi->max_speed_hz;
2825 if (!xfer->speed_hz)
2826 xfer->speed_hz = ctlr->max_speed_hz;
2827
2828 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
2829 xfer->speed_hz = ctlr->max_speed_hz;
2830
2831 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
2832 return -EINVAL;
2833
2834 /*
2835 * SPI transfer length should be multiple of SPI word size
2836 * where SPI word size should be power-of-two multiple
2837 */
2838 if (xfer->bits_per_word <= 8)
2839 w_size = 1;
2840 else if (xfer->bits_per_word <= 16)
2841 w_size = 2;
2842 else
2843 w_size = 4;
2844
2845 /* No partial transfers accepted */
2846 if (xfer->len % w_size)
2847 return -EINVAL;
2848
2849 if (xfer->speed_hz && ctlr->min_speed_hz &&
2850 xfer->speed_hz < ctlr->min_speed_hz)
2851 return -EINVAL;
2852
2853 if (xfer->tx_buf && !xfer->tx_nbits)
2854 xfer->tx_nbits = SPI_NBITS_SINGLE;
2855 if (xfer->rx_buf && !xfer->rx_nbits)
2856 xfer->rx_nbits = SPI_NBITS_SINGLE;
2857 /* check transfer tx/rx_nbits:
2858 * 1. check the value matches one of single, dual and quad
2859 * 2. check tx/rx_nbits match the mode in spi_device
2860 */
2861 if (xfer->tx_buf) {
2862 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2863 xfer->tx_nbits != SPI_NBITS_DUAL &&
2864 xfer->tx_nbits != SPI_NBITS_QUAD)
2865 return -EINVAL;
2866 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2867 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2868 return -EINVAL;
2869 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2870 !(spi->mode & SPI_TX_QUAD))
2871 return -EINVAL;
2872 }
2873 /* check transfer rx_nbits */
2874 if (xfer->rx_buf) {
2875 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2876 xfer->rx_nbits != SPI_NBITS_DUAL &&
2877 xfer->rx_nbits != SPI_NBITS_QUAD)
2878 return -EINVAL;
2879 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2880 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2881 return -EINVAL;
2882 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2883 !(spi->mode & SPI_RX_QUAD))
2884 return -EINVAL;
2885 }
2886 }
2887
2888 message->status = -EINPROGRESS;
2889
2890 return 0;
2891}
2892
2893static int __spi_async(struct spi_device *spi, struct spi_message *message)
2894{
2895 struct spi_controller *ctlr = spi->controller;
2896
2897 message->spi = spi;
2898
2899 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
2900 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2901
2902 trace_spi_message_submit(message);
2903
2904 return ctlr->transfer(spi, message);
2905}
2906
2907/**
2908 * spi_async - asynchronous SPI transfer
2909 * @spi: device with which data will be exchanged
2910 * @message: describes the data transfers, including completion callback
2911 * Context: any (irqs may be blocked, etc)
2912 *
2913 * This call may be used in_irq and other contexts which can't sleep,
2914 * as well as from task contexts which can sleep.
2915 *
2916 * The completion callback is invoked in a context which can't sleep.
2917 * Before that invocation, the value of message->status is undefined.
2918 * When the callback is issued, message->status holds either zero (to
2919 * indicate complete success) or a negative error code. After that
2920 * callback returns, the driver which issued the transfer request may
2921 * deallocate the associated memory; it's no longer in use by any SPI
2922 * core or controller driver code.
2923 *
2924 * Note that although all messages to a spi_device are handled in
2925 * FIFO order, messages may go to different devices in other orders.
2926 * Some device might be higher priority, or have various "hard" access
2927 * time requirements, for example.
2928 *
2929 * On detection of any fault during the transfer, processing of
2930 * the entire message is aborted, and the device is deselected.
2931 * Until returning from the associated message completion callback,
2932 * no other spi_message queued to that device will be processed.
2933 * (This rule applies equally to all the synchronous transfer calls,
2934 * which are wrappers around this core asynchronous primitive.)
2935 *
2936 * Return: zero on success, else a negative error code.
2937 */
2938int spi_async(struct spi_device *spi, struct spi_message *message)
2939{
2940 struct spi_controller *ctlr = spi->controller;
2941 int ret;
2942 unsigned long flags;
2943
2944 ret = __spi_validate(spi, message);
2945 if (ret != 0)
2946 return ret;
2947
2948 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
2949
2950 if (ctlr->bus_lock_flag)
2951 ret = -EBUSY;
2952 else
2953 ret = __spi_async(spi, message);
2954
2955 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
2956
2957 return ret;
2958}
2959EXPORT_SYMBOL_GPL(spi_async);
2960
2961/**
2962 * spi_async_locked - version of spi_async with exclusive bus usage
2963 * @spi: device with which data will be exchanged
2964 * @message: describes the data transfers, including completion callback
2965 * Context: any (irqs may be blocked, etc)
2966 *
2967 * This call may be used in_irq and other contexts which can't sleep,
2968 * as well as from task contexts which can sleep.
2969 *
2970 * The completion callback is invoked in a context which can't sleep.
2971 * Before that invocation, the value of message->status is undefined.
2972 * When the callback is issued, message->status holds either zero (to
2973 * indicate complete success) or a negative error code. After that
2974 * callback returns, the driver which issued the transfer request may
2975 * deallocate the associated memory; it's no longer in use by any SPI
2976 * core or controller driver code.
2977 *
2978 * Note that although all messages to a spi_device are handled in
2979 * FIFO order, messages may go to different devices in other orders.
2980 * Some device might be higher priority, or have various "hard" access
2981 * time requirements, for example.
2982 *
2983 * On detection of any fault during the transfer, processing of
2984 * the entire message is aborted, and the device is deselected.
2985 * Until returning from the associated message completion callback,
2986 * no other spi_message queued to that device will be processed.
2987 * (This rule applies equally to all the synchronous transfer calls,
2988 * which are wrappers around this core asynchronous primitive.)
2989 *
2990 * Return: zero on success, else a negative error code.
2991 */
2992int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2993{
2994 struct spi_controller *ctlr = spi->controller;
2995 int ret;
2996 unsigned long flags;
2997
2998 ret = __spi_validate(spi, message);
2999 if (ret != 0)
3000 return ret;
3001
3002 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3003
3004 ret = __spi_async(spi, message);
3005
3006 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3007
3008 return ret;
3009
3010}
3011EXPORT_SYMBOL_GPL(spi_async_locked);
3012
3013
3014int spi_flash_read(struct spi_device *spi,
3015 struct spi_flash_read_message *msg)
3016
3017{
3018 struct spi_controller *master = spi->controller;
3019 struct device *rx_dev = NULL;
3020 int ret;
3021
3022 if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
3023 msg->addr_nbits == SPI_NBITS_DUAL) &&
3024 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3025 return -EINVAL;
3026 if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
3027 msg->addr_nbits == SPI_NBITS_QUAD) &&
3028 !(spi->mode & SPI_TX_QUAD))
3029 return -EINVAL;
3030 if (msg->data_nbits == SPI_NBITS_DUAL &&
3031 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3032 return -EINVAL;
3033 if (msg->data_nbits == SPI_NBITS_QUAD &&
3034 !(spi->mode & SPI_RX_QUAD))
3035 return -EINVAL;
3036
3037 if (master->auto_runtime_pm) {
3038 ret = pm_runtime_get_sync(master->dev.parent);
3039 if (ret < 0) {
3040 dev_err(&master->dev, "Failed to power device: %d\n",
3041 ret);
3042 return ret;
3043 }
3044 }
3045
3046 mutex_lock(&master->bus_lock_mutex);
3047 mutex_lock(&master->io_mutex);
3048 if (master->dma_rx && master->spi_flash_can_dma(spi, msg)) {
3049 rx_dev = master->dma_rx->device->dev;
3050 ret = spi_map_buf(master, rx_dev, &msg->rx_sg,
3051 msg->buf, msg->len,
3052 DMA_FROM_DEVICE);
3053 if (!ret)
3054 msg->cur_msg_mapped = true;
3055 }
3056 ret = master->spi_flash_read(spi, msg);
3057 if (msg->cur_msg_mapped)
3058 spi_unmap_buf(master, rx_dev, &msg->rx_sg,
3059 DMA_FROM_DEVICE);
3060 mutex_unlock(&master->io_mutex);
3061 mutex_unlock(&master->bus_lock_mutex);
3062
3063 if (master->auto_runtime_pm)
3064 pm_runtime_put(master->dev.parent);
3065
3066 return ret;
3067}
3068EXPORT_SYMBOL_GPL(spi_flash_read);
3069
3070/*-------------------------------------------------------------------------*/
3071
3072/* Utility methods for SPI protocol drivers, layered on
3073 * top of the core. Some other utility methods are defined as
3074 * inline functions.
3075 */
3076
3077static void spi_complete(void *arg)
3078{
3079 complete(arg);
3080}
3081
3082static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3083{
3084 DECLARE_COMPLETION_ONSTACK(done);
3085 int status;
3086 struct spi_controller *ctlr = spi->controller;
3087 unsigned long flags;
3088
3089 status = __spi_validate(spi, message);
3090 if (status != 0)
3091 return status;
3092
3093 message->complete = spi_complete;
3094 message->context = &done;
3095 message->spi = spi;
3096
3097 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3098 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3099
3100 /* If we're not using the legacy transfer method then we will
3101 * try to transfer in the calling context so special case.
3102 * This code would be less tricky if we could remove the
3103 * support for driver implemented message queues.
3104 */
3105 if (ctlr->transfer == spi_queued_transfer) {
3106 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3107
3108 trace_spi_message_submit(message);
3109
3110 status = __spi_queued_transfer(spi, message, false);
3111
3112 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3113 } else {
3114 status = spi_async_locked(spi, message);
3115 }
3116
3117 if (status == 0) {
3118 /* Push out the messages in the calling context if we
3119 * can.
3120 */
3121 if (ctlr->transfer == spi_queued_transfer) {
3122 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3123 spi_sync_immediate);
3124 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3125 spi_sync_immediate);
3126 __spi_pump_messages(ctlr, false);
3127 }
3128
3129 wait_for_completion(&done);
3130 status = message->status;
3131 }
3132 message->context = NULL;
3133 return status;
3134}
3135
3136/**
3137 * spi_sync - blocking/synchronous SPI data transfers
3138 * @spi: device with which data will be exchanged
3139 * @message: describes the data transfers
3140 * Context: can sleep
3141 *
3142 * This call may only be used from a context that may sleep. The sleep
3143 * is non-interruptible, and has no timeout. Low-overhead controller
3144 * drivers may DMA directly into and out of the message buffers.
3145 *
3146 * Note that the SPI device's chip select is active during the message,
3147 * and then is normally disabled between messages. Drivers for some
3148 * frequently-used devices may want to minimize costs of selecting a chip,
3149 * by leaving it selected in anticipation that the next message will go
3150 * to the same chip. (That may increase power usage.)
3151 *
3152 * Also, the caller is guaranteeing that the memory associated with the
3153 * message will not be freed before this call returns.
3154 *
3155 * Return: zero on success, else a negative error code.
3156 */
3157int spi_sync(struct spi_device *spi, struct spi_message *message)
3158{
3159 int ret;
3160
3161 mutex_lock(&spi->controller->bus_lock_mutex);
3162 ret = __spi_sync(spi, message);
3163 mutex_unlock(&spi->controller->bus_lock_mutex);
3164
3165 return ret;
3166}
3167EXPORT_SYMBOL_GPL(spi_sync);
3168
3169/**
3170 * spi_sync_locked - version of spi_sync with exclusive bus usage
3171 * @spi: device with which data will be exchanged
3172 * @message: describes the data transfers
3173 * Context: can sleep
3174 *
3175 * This call may only be used from a context that may sleep. The sleep
3176 * is non-interruptible, and has no timeout. Low-overhead controller
3177 * drivers may DMA directly into and out of the message buffers.
3178 *
3179 * This call should be used by drivers that require exclusive access to the
3180 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3181 * be released by a spi_bus_unlock call when the exclusive access is over.
3182 *
3183 * Return: zero on success, else a negative error code.
3184 */
3185int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3186{
3187 return __spi_sync(spi, message);
3188}
3189EXPORT_SYMBOL_GPL(spi_sync_locked);
3190
3191/**
3192 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3193 * @ctlr: SPI bus master that should be locked for exclusive bus access
3194 * Context: can sleep
3195 *
3196 * This call may only be used from a context that may sleep. The sleep
3197 * is non-interruptible, and has no timeout.
3198 *
3199 * This call should be used by drivers that require exclusive access to the
3200 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3201 * exclusive access is over. Data transfer must be done by spi_sync_locked
3202 * and spi_async_locked calls when the SPI bus lock is held.
3203 *
3204 * Return: always zero.
3205 */
3206int spi_bus_lock(struct spi_controller *ctlr)
3207{
3208 unsigned long flags;
3209
3210 mutex_lock(&ctlr->bus_lock_mutex);
3211
3212 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3213 ctlr->bus_lock_flag = 1;
3214 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3215
3216 /* mutex remains locked until spi_bus_unlock is called */
3217
3218 return 0;
3219}
3220EXPORT_SYMBOL_GPL(spi_bus_lock);
3221
3222/**
3223 * spi_bus_unlock - release the lock for exclusive SPI bus usage
3224 * @ctlr: SPI bus master that was locked for exclusive bus access
3225 * Context: can sleep
3226 *
3227 * This call may only be used from a context that may sleep. The sleep
3228 * is non-interruptible, and has no timeout.
3229 *
3230 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3231 * call.
3232 *
3233 * Return: always zero.
3234 */
3235int spi_bus_unlock(struct spi_controller *ctlr)
3236{
3237 ctlr->bus_lock_flag = 0;
3238
3239 mutex_unlock(&ctlr->bus_lock_mutex);
3240
3241 return 0;
3242}
3243EXPORT_SYMBOL_GPL(spi_bus_unlock);
3244
3245/* portable code must never pass more than 32 bytes */
3246#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3247
3248static u8 *buf;
3249
3250/**
3251 * spi_write_then_read - SPI synchronous write followed by read
3252 * @spi: device with which data will be exchanged
3253 * @txbuf: data to be written (need not be dma-safe)
3254 * @n_tx: size of txbuf, in bytes
3255 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3256 * @n_rx: size of rxbuf, in bytes
3257 * Context: can sleep
3258 *
3259 * This performs a half duplex MicroWire style transaction with the
3260 * device, sending txbuf and then reading rxbuf. The return value
3261 * is zero for success, else a negative errno status code.
3262 * This call may only be used from a context that may sleep.
3263 *
3264 * Parameters to this routine are always copied using a small buffer;
3265 * portable code should never use this for more than 32 bytes.
3266 * Performance-sensitive or bulk transfer code should instead use
3267 * spi_{async,sync}() calls with dma-safe buffers.
3268 *
3269 * Return: zero on success, else a negative error code.
3270 */
3271int spi_write_then_read(struct spi_device *spi,
3272 const void *txbuf, unsigned n_tx,
3273 void *rxbuf, unsigned n_rx)
3274{
3275 static DEFINE_MUTEX(lock);
3276
3277 int status;
3278 struct spi_message message;
3279 struct spi_transfer x[2];
3280 u8 *local_buf;
3281
3282 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3283 * copying here, (as a pure convenience thing), but we can
3284 * keep heap costs out of the hot path unless someone else is
3285 * using the pre-allocated buffer or the transfer is too large.
3286 */
3287 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
3288 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3289 GFP_KERNEL | GFP_DMA);
3290 if (!local_buf)
3291 return -ENOMEM;
3292 } else {
3293 local_buf = buf;
3294 }
3295
3296 spi_message_init(&message);
3297 memset(x, 0, sizeof(x));
3298 if (n_tx) {
3299 x[0].len = n_tx;
3300 spi_message_add_tail(&x[0], &message);
3301 }
3302 if (n_rx) {
3303 x[1].len = n_rx;
3304 spi_message_add_tail(&x[1], &message);
3305 }
3306
3307 memcpy(local_buf, txbuf, n_tx);
3308 x[0].tx_buf = local_buf;
3309 x[1].rx_buf = local_buf + n_tx;
3310
3311 /* do the i/o */
3312 status = spi_sync(spi, &message);
3313 if (status == 0)
3314 memcpy(rxbuf, x[1].rx_buf, n_rx);
3315
3316 if (x[0].tx_buf == buf)
3317 mutex_unlock(&lock);
3318 else
3319 kfree(local_buf);
3320
3321 return status;
3322}
3323EXPORT_SYMBOL_GPL(spi_write_then_read);
3324
3325/*-------------------------------------------------------------------------*/
3326
3327#if IS_ENABLED(CONFIG_OF_DYNAMIC)
3328static int __spi_of_device_match(struct device *dev, void *data)
3329{
3330 return dev->of_node == data;
3331}
3332
3333/* must call put_device() when done with returned spi_device device */
3334static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3335{
3336 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3337 __spi_of_device_match);
3338 return dev ? to_spi_device(dev) : NULL;
3339}
3340
3341static int __spi_of_controller_match(struct device *dev, const void *data)
3342{
3343 return dev->of_node == data;
3344}
3345
3346/* the spi controllers are not using spi_bus, so we find it with another way */
3347static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
3348{
3349 struct device *dev;
3350
3351 dev = class_find_device(&spi_master_class, NULL, node,
3352 __spi_of_controller_match);
3353 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3354 dev = class_find_device(&spi_slave_class, NULL, node,
3355 __spi_of_controller_match);
3356 if (!dev)
3357 return NULL;
3358
3359 /* reference got in class_find_device */
3360 return container_of(dev, struct spi_controller, dev);
3361}
3362
3363static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3364 void *arg)
3365{
3366 struct of_reconfig_data *rd = arg;
3367 struct spi_controller *ctlr;
3368 struct spi_device *spi;
3369
3370 switch (of_reconfig_get_state_change(action, arg)) {
3371 case OF_RECONFIG_CHANGE_ADD:
3372 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
3373 if (ctlr == NULL)
3374 return NOTIFY_OK; /* not for us */
3375
3376 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3377 put_device(&ctlr->dev);
3378 return NOTIFY_OK;
3379 }
3380
3381 spi = of_register_spi_device(ctlr, rd->dn);
3382 put_device(&ctlr->dev);
3383
3384 if (IS_ERR(spi)) {
3385 pr_err("%s: failed to create for '%pOF'\n",
3386 __func__, rd->dn);
3387 of_node_clear_flag(rd->dn, OF_POPULATED);
3388 return notifier_from_errno(PTR_ERR(spi));
3389 }
3390 break;
3391
3392 case OF_RECONFIG_CHANGE_REMOVE:
3393 /* already depopulated? */
3394 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3395 return NOTIFY_OK;
3396
3397 /* find our device by node */
3398 spi = of_find_spi_device_by_node(rd->dn);
3399 if (spi == NULL)
3400 return NOTIFY_OK; /* no? not meant for us */
3401
3402 /* unregister takes one ref away */
3403 spi_unregister_device(spi);
3404
3405 /* and put the reference of the find */
3406 put_device(&spi->dev);
3407 break;
3408 }
3409
3410 return NOTIFY_OK;
3411}
3412
3413static struct notifier_block spi_of_notifier = {
3414 .notifier_call = of_spi_notify,
3415};
3416#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3417extern struct notifier_block spi_of_notifier;
3418#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3419
3420#if IS_ENABLED(CONFIG_ACPI)
3421static int spi_acpi_controller_match(struct device *dev, const void *data)
3422{
3423 return ACPI_COMPANION(dev->parent) == data;
3424}
3425
3426static int spi_acpi_device_match(struct device *dev, void *data)
3427{
3428 return ACPI_COMPANION(dev) == data;
3429}
3430
3431static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
3432{
3433 struct device *dev;
3434
3435 dev = class_find_device(&spi_master_class, NULL, adev,
3436 spi_acpi_controller_match);
3437 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3438 dev = class_find_device(&spi_slave_class, NULL, adev,
3439 spi_acpi_controller_match);
3440 if (!dev)
3441 return NULL;
3442
3443 return container_of(dev, struct spi_controller, dev);
3444}
3445
3446static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3447{
3448 struct device *dev;
3449
3450 dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3451
3452 return dev ? to_spi_device(dev) : NULL;
3453}
3454
3455static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3456 void *arg)
3457{
3458 struct acpi_device *adev = arg;
3459 struct spi_controller *ctlr;
3460 struct spi_device *spi;
3461
3462 switch (value) {
3463 case ACPI_RECONFIG_DEVICE_ADD:
3464 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
3465 if (!ctlr)
3466 break;
3467
3468 acpi_register_spi_device(ctlr, adev);
3469 put_device(&ctlr->dev);
3470 break;
3471 case ACPI_RECONFIG_DEVICE_REMOVE:
3472 if (!acpi_device_enumerated(adev))
3473 break;
3474
3475 spi = acpi_spi_find_device_by_adev(adev);
3476 if (!spi)
3477 break;
3478
3479 spi_unregister_device(spi);
3480 put_device(&spi->dev);
3481 break;
3482 }
3483
3484 return NOTIFY_OK;
3485}
3486
3487static struct notifier_block spi_acpi_notifier = {
3488 .notifier_call = acpi_spi_notify,
3489};
3490#else
3491extern struct notifier_block spi_acpi_notifier;
3492#endif
3493
3494static int __init spi_init(void)
3495{
3496 int status;
3497
3498 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
3499 if (!buf) {
3500 status = -ENOMEM;
3501 goto err0;
3502 }
3503
3504 status = bus_register(&spi_bus_type);
3505 if (status < 0)
3506 goto err1;
3507
3508 status = class_register(&spi_master_class);
3509 if (status < 0)
3510 goto err2;
3511
3512 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
3513 status = class_register(&spi_slave_class);
3514 if (status < 0)
3515 goto err3;
3516 }
3517
3518 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
3519 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3520 if (IS_ENABLED(CONFIG_ACPI))
3521 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
3522
3523 return 0;
3524
3525err3:
3526 class_unregister(&spi_master_class);
3527err2:
3528 bus_unregister(&spi_bus_type);
3529err1:
3530 kfree(buf);
3531 buf = NULL;
3532err0:
3533 return status;
3534}
3535
3536/* board_info is normally registered in arch_initcall(),
3537 * but even essential drivers wait till later
3538 *
3539 * REVISIT only boardinfo really needs static linking. the rest (device and
3540 * driver registration) _could_ be dynamically linked (modular) ... costs
3541 * include needing to have boardinfo data structures be much more public.
3542 */
3543postcore_initcall(spi_init);
3544
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 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#include <linux/kernel.h>
23#include <linux/kmod.h>
24#include <linux/device.h>
25#include <linux/init.h>
26#include <linux/cache.h>
27#include <linux/dma-mapping.h>
28#include <linux/dmaengine.h>
29#include <linux/mutex.h>
30#include <linux/of_device.h>
31#include <linux/of_irq.h>
32#include <linux/slab.h>
33#include <linux/mod_devicetable.h>
34#include <linux/spi/spi.h>
35#include <linux/of_gpio.h>
36#include <linux/pm_runtime.h>
37#include <linux/export.h>
38#include <linux/sched/rt.h>
39#include <linux/delay.h>
40#include <linux/kthread.h>
41#include <linux/ioport.h>
42#include <linux/acpi.h>
43
44#define CREATE_TRACE_POINTS
45#include <trace/events/spi.h>
46
47static void spidev_release(struct device *dev)
48{
49 struct spi_device *spi = to_spi_device(dev);
50
51 /* spi masters may cleanup for released devices */
52 if (spi->master->cleanup)
53 spi->master->cleanup(spi);
54
55 spi_master_put(spi->master);
56 kfree(spi);
57}
58
59static ssize_t
60modalias_show(struct device *dev, struct device_attribute *a, char *buf)
61{
62 const struct spi_device *spi = to_spi_device(dev);
63 int len;
64
65 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
66 if (len != -ENODEV)
67 return len;
68
69 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
70}
71static DEVICE_ATTR_RO(modalias);
72
73static struct attribute *spi_dev_attrs[] = {
74 &dev_attr_modalias.attr,
75 NULL,
76};
77ATTRIBUTE_GROUPS(spi_dev);
78
79/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
80 * and the sysfs version makes coldplug work too.
81 */
82
83static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
84 const struct spi_device *sdev)
85{
86 while (id->name[0]) {
87 if (!strcmp(sdev->modalias, id->name))
88 return id;
89 id++;
90 }
91 return NULL;
92}
93
94const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
95{
96 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
97
98 return spi_match_id(sdrv->id_table, sdev);
99}
100EXPORT_SYMBOL_GPL(spi_get_device_id);
101
102static int spi_match_device(struct device *dev, struct device_driver *drv)
103{
104 const struct spi_device *spi = to_spi_device(dev);
105 const struct spi_driver *sdrv = to_spi_driver(drv);
106
107 /* Attempt an OF style match */
108 if (of_driver_match_device(dev, drv))
109 return 1;
110
111 /* Then try ACPI */
112 if (acpi_driver_match_device(dev, drv))
113 return 1;
114
115 if (sdrv->id_table)
116 return !!spi_match_id(sdrv->id_table, spi);
117
118 return strcmp(spi->modalias, drv->name) == 0;
119}
120
121static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
122{
123 const struct spi_device *spi = to_spi_device(dev);
124 int rc;
125
126 rc = acpi_device_uevent_modalias(dev, env);
127 if (rc != -ENODEV)
128 return rc;
129
130 add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
131 return 0;
132}
133
134#ifdef CONFIG_PM_SLEEP
135static int spi_legacy_suspend(struct device *dev, pm_message_t message)
136{
137 int value = 0;
138 struct spi_driver *drv = to_spi_driver(dev->driver);
139
140 /* suspend will stop irqs and dma; no more i/o */
141 if (drv) {
142 if (drv->suspend)
143 value = drv->suspend(to_spi_device(dev), message);
144 else
145 dev_dbg(dev, "... can't suspend\n");
146 }
147 return value;
148}
149
150static int spi_legacy_resume(struct device *dev)
151{
152 int value = 0;
153 struct spi_driver *drv = to_spi_driver(dev->driver);
154
155 /* resume may restart the i/o queue */
156 if (drv) {
157 if (drv->resume)
158 value = drv->resume(to_spi_device(dev));
159 else
160 dev_dbg(dev, "... can't resume\n");
161 }
162 return value;
163}
164
165static int spi_pm_suspend(struct device *dev)
166{
167 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
168
169 if (pm)
170 return pm_generic_suspend(dev);
171 else
172 return spi_legacy_suspend(dev, PMSG_SUSPEND);
173}
174
175static int spi_pm_resume(struct device *dev)
176{
177 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
178
179 if (pm)
180 return pm_generic_resume(dev);
181 else
182 return spi_legacy_resume(dev);
183}
184
185static int spi_pm_freeze(struct device *dev)
186{
187 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
188
189 if (pm)
190 return pm_generic_freeze(dev);
191 else
192 return spi_legacy_suspend(dev, PMSG_FREEZE);
193}
194
195static int spi_pm_thaw(struct device *dev)
196{
197 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
198
199 if (pm)
200 return pm_generic_thaw(dev);
201 else
202 return spi_legacy_resume(dev);
203}
204
205static int spi_pm_poweroff(struct device *dev)
206{
207 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
208
209 if (pm)
210 return pm_generic_poweroff(dev);
211 else
212 return spi_legacy_suspend(dev, PMSG_HIBERNATE);
213}
214
215static int spi_pm_restore(struct device *dev)
216{
217 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
218
219 if (pm)
220 return pm_generic_restore(dev);
221 else
222 return spi_legacy_resume(dev);
223}
224#else
225#define spi_pm_suspend NULL
226#define spi_pm_resume NULL
227#define spi_pm_freeze NULL
228#define spi_pm_thaw NULL
229#define spi_pm_poweroff NULL
230#define spi_pm_restore NULL
231#endif
232
233static const struct dev_pm_ops spi_pm = {
234 .suspend = spi_pm_suspend,
235 .resume = spi_pm_resume,
236 .freeze = spi_pm_freeze,
237 .thaw = spi_pm_thaw,
238 .poweroff = spi_pm_poweroff,
239 .restore = spi_pm_restore,
240 SET_RUNTIME_PM_OPS(
241 pm_generic_runtime_suspend,
242 pm_generic_runtime_resume,
243 NULL
244 )
245};
246
247struct bus_type spi_bus_type = {
248 .name = "spi",
249 .dev_groups = spi_dev_groups,
250 .match = spi_match_device,
251 .uevent = spi_uevent,
252 .pm = &spi_pm,
253};
254EXPORT_SYMBOL_GPL(spi_bus_type);
255
256
257static int spi_drv_probe(struct device *dev)
258{
259 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
260 int ret;
261
262 acpi_dev_pm_attach(dev, true);
263 ret = sdrv->probe(to_spi_device(dev));
264 if (ret)
265 acpi_dev_pm_detach(dev, true);
266
267 return ret;
268}
269
270static int spi_drv_remove(struct device *dev)
271{
272 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
273 int ret;
274
275 ret = sdrv->remove(to_spi_device(dev));
276 acpi_dev_pm_detach(dev, true);
277
278 return ret;
279}
280
281static void spi_drv_shutdown(struct device *dev)
282{
283 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
284
285 sdrv->shutdown(to_spi_device(dev));
286}
287
288/**
289 * spi_register_driver - register a SPI driver
290 * @sdrv: the driver to register
291 * Context: can sleep
292 */
293int spi_register_driver(struct spi_driver *sdrv)
294{
295 sdrv->driver.bus = &spi_bus_type;
296 if (sdrv->probe)
297 sdrv->driver.probe = spi_drv_probe;
298 if (sdrv->remove)
299 sdrv->driver.remove = spi_drv_remove;
300 if (sdrv->shutdown)
301 sdrv->driver.shutdown = spi_drv_shutdown;
302 return driver_register(&sdrv->driver);
303}
304EXPORT_SYMBOL_GPL(spi_register_driver);
305
306/*-------------------------------------------------------------------------*/
307
308/* SPI devices should normally not be created by SPI device drivers; that
309 * would make them board-specific. Similarly with SPI master drivers.
310 * Device registration normally goes into like arch/.../mach.../board-YYY.c
311 * with other readonly (flashable) information about mainboard devices.
312 */
313
314struct boardinfo {
315 struct list_head list;
316 struct spi_board_info board_info;
317};
318
319static LIST_HEAD(board_list);
320static LIST_HEAD(spi_master_list);
321
322/*
323 * Used to protect add/del opertion for board_info list and
324 * spi_master list, and their matching process
325 */
326static DEFINE_MUTEX(board_lock);
327
328/**
329 * spi_alloc_device - Allocate a new SPI device
330 * @master: Controller to which device is connected
331 * Context: can sleep
332 *
333 * Allows a driver to allocate and initialize a spi_device without
334 * registering it immediately. This allows a driver to directly
335 * fill the spi_device with device parameters before calling
336 * spi_add_device() on it.
337 *
338 * Caller is responsible to call spi_add_device() on the returned
339 * spi_device structure to add it to the SPI master. If the caller
340 * needs to discard the spi_device without adding it, then it should
341 * call spi_dev_put() on it.
342 *
343 * Returns a pointer to the new device, or NULL.
344 */
345struct spi_device *spi_alloc_device(struct spi_master *master)
346{
347 struct spi_device *spi;
348 struct device *dev = master->dev.parent;
349
350 if (!spi_master_get(master))
351 return NULL;
352
353 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
354 if (!spi) {
355 dev_err(dev, "cannot alloc spi_device\n");
356 spi_master_put(master);
357 return NULL;
358 }
359
360 spi->master = master;
361 spi->dev.parent = &master->dev;
362 spi->dev.bus = &spi_bus_type;
363 spi->dev.release = spidev_release;
364 spi->cs_gpio = -ENOENT;
365 device_initialize(&spi->dev);
366 return spi;
367}
368EXPORT_SYMBOL_GPL(spi_alloc_device);
369
370static void spi_dev_set_name(struct spi_device *spi)
371{
372 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
373
374 if (adev) {
375 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
376 return;
377 }
378
379 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
380 spi->chip_select);
381}
382
383static int spi_dev_check(struct device *dev, void *data)
384{
385 struct spi_device *spi = to_spi_device(dev);
386 struct spi_device *new_spi = data;
387
388 if (spi->master == new_spi->master &&
389 spi->chip_select == new_spi->chip_select)
390 return -EBUSY;
391 return 0;
392}
393
394/**
395 * spi_add_device - Add spi_device allocated with spi_alloc_device
396 * @spi: spi_device to register
397 *
398 * Companion function to spi_alloc_device. Devices allocated with
399 * spi_alloc_device can be added onto the spi bus with this function.
400 *
401 * Returns 0 on success; negative errno on failure
402 */
403int spi_add_device(struct spi_device *spi)
404{
405 static DEFINE_MUTEX(spi_add_lock);
406 struct spi_master *master = spi->master;
407 struct device *dev = master->dev.parent;
408 int status;
409
410 /* Chipselects are numbered 0..max; validate. */
411 if (spi->chip_select >= master->num_chipselect) {
412 dev_err(dev, "cs%d >= max %d\n",
413 spi->chip_select,
414 master->num_chipselect);
415 return -EINVAL;
416 }
417
418 /* Set the bus ID string */
419 spi_dev_set_name(spi);
420
421 /* We need to make sure there's no other device with this
422 * chipselect **BEFORE** we call setup(), else we'll trash
423 * its configuration. Lock against concurrent add() calls.
424 */
425 mutex_lock(&spi_add_lock);
426
427 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
428 if (status) {
429 dev_err(dev, "chipselect %d already in use\n",
430 spi->chip_select);
431 goto done;
432 }
433
434 if (master->cs_gpios)
435 spi->cs_gpio = master->cs_gpios[spi->chip_select];
436
437 /* Drivers may modify this initial i/o setup, but will
438 * normally rely on the device being setup. Devices
439 * using SPI_CS_HIGH can't coexist well otherwise...
440 */
441 status = spi_setup(spi);
442 if (status < 0) {
443 dev_err(dev, "can't setup %s, status %d\n",
444 dev_name(&spi->dev), status);
445 goto done;
446 }
447
448 /* Device may be bound to an active driver when this returns */
449 status = device_add(&spi->dev);
450 if (status < 0)
451 dev_err(dev, "can't add %s, status %d\n",
452 dev_name(&spi->dev), status);
453 else
454 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
455
456done:
457 mutex_unlock(&spi_add_lock);
458 return status;
459}
460EXPORT_SYMBOL_GPL(spi_add_device);
461
462/**
463 * spi_new_device - instantiate one new SPI device
464 * @master: Controller to which device is connected
465 * @chip: Describes the SPI device
466 * Context: can sleep
467 *
468 * On typical mainboards, this is purely internal; and it's not needed
469 * after board init creates the hard-wired devices. Some development
470 * platforms may not be able to use spi_register_board_info though, and
471 * this is exported so that for example a USB or parport based adapter
472 * driver could add devices (which it would learn about out-of-band).
473 *
474 * Returns the new device, or NULL.
475 */
476struct spi_device *spi_new_device(struct spi_master *master,
477 struct spi_board_info *chip)
478{
479 struct spi_device *proxy;
480 int status;
481
482 /* NOTE: caller did any chip->bus_num checks necessary.
483 *
484 * Also, unless we change the return value convention to use
485 * error-or-pointer (not NULL-or-pointer), troubleshootability
486 * suggests syslogged diagnostics are best here (ugh).
487 */
488
489 proxy = spi_alloc_device(master);
490 if (!proxy)
491 return NULL;
492
493 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
494
495 proxy->chip_select = chip->chip_select;
496 proxy->max_speed_hz = chip->max_speed_hz;
497 proxy->mode = chip->mode;
498 proxy->irq = chip->irq;
499 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
500 proxy->dev.platform_data = (void *) chip->platform_data;
501 proxy->controller_data = chip->controller_data;
502 proxy->controller_state = NULL;
503
504 status = spi_add_device(proxy);
505 if (status < 0) {
506 spi_dev_put(proxy);
507 return NULL;
508 }
509
510 return proxy;
511}
512EXPORT_SYMBOL_GPL(spi_new_device);
513
514static void spi_match_master_to_boardinfo(struct spi_master *master,
515 struct spi_board_info *bi)
516{
517 struct spi_device *dev;
518
519 if (master->bus_num != bi->bus_num)
520 return;
521
522 dev = spi_new_device(master, bi);
523 if (!dev)
524 dev_err(master->dev.parent, "can't create new device for %s\n",
525 bi->modalias);
526}
527
528/**
529 * spi_register_board_info - register SPI devices for a given board
530 * @info: array of chip descriptors
531 * @n: how many descriptors are provided
532 * Context: can sleep
533 *
534 * Board-specific early init code calls this (probably during arch_initcall)
535 * with segments of the SPI device table. Any device nodes are created later,
536 * after the relevant parent SPI controller (bus_num) is defined. We keep
537 * this table of devices forever, so that reloading a controller driver will
538 * not make Linux forget about these hard-wired devices.
539 *
540 * Other code can also call this, e.g. a particular add-on board might provide
541 * SPI devices through its expansion connector, so code initializing that board
542 * would naturally declare its SPI devices.
543 *
544 * The board info passed can safely be __initdata ... but be careful of
545 * any embedded pointers (platform_data, etc), they're copied as-is.
546 */
547int spi_register_board_info(struct spi_board_info const *info, unsigned n)
548{
549 struct boardinfo *bi;
550 int i;
551
552 bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
553 if (!bi)
554 return -ENOMEM;
555
556 for (i = 0; i < n; i++, bi++, info++) {
557 struct spi_master *master;
558
559 memcpy(&bi->board_info, info, sizeof(*info));
560 mutex_lock(&board_lock);
561 list_add_tail(&bi->list, &board_list);
562 list_for_each_entry(master, &spi_master_list, list)
563 spi_match_master_to_boardinfo(master, &bi->board_info);
564 mutex_unlock(&board_lock);
565 }
566
567 return 0;
568}
569
570/*-------------------------------------------------------------------------*/
571
572static void spi_set_cs(struct spi_device *spi, bool enable)
573{
574 if (spi->mode & SPI_CS_HIGH)
575 enable = !enable;
576
577 if (spi->cs_gpio >= 0)
578 gpio_set_value(spi->cs_gpio, !enable);
579 else if (spi->master->set_cs)
580 spi->master->set_cs(spi, !enable);
581}
582
583#ifdef CONFIG_HAS_DMA
584static int spi_map_buf(struct spi_master *master, struct device *dev,
585 struct sg_table *sgt, void *buf, size_t len,
586 enum dma_data_direction dir)
587{
588 const bool vmalloced_buf = is_vmalloc_addr(buf);
589 const int desc_len = vmalloced_buf ? PAGE_SIZE : master->max_dma_len;
590 const int sgs = DIV_ROUND_UP(len, desc_len);
591 struct page *vm_page;
592 void *sg_buf;
593 size_t min;
594 int i, ret;
595
596 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
597 if (ret != 0)
598 return ret;
599
600 for (i = 0; i < sgs; i++) {
601 min = min_t(size_t, len, desc_len);
602
603 if (vmalloced_buf) {
604 vm_page = vmalloc_to_page(buf);
605 if (!vm_page) {
606 sg_free_table(sgt);
607 return -ENOMEM;
608 }
609 sg_buf = page_address(vm_page) +
610 ((size_t)buf & ~PAGE_MASK);
611 } else {
612 sg_buf = buf;
613 }
614
615 sg_set_buf(&sgt->sgl[i], sg_buf, min);
616
617 buf += min;
618 len -= min;
619 }
620
621 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
622 if (ret < 0) {
623 sg_free_table(sgt);
624 return ret;
625 }
626
627 sgt->nents = ret;
628
629 return 0;
630}
631
632static void spi_unmap_buf(struct spi_master *master, struct device *dev,
633 struct sg_table *sgt, enum dma_data_direction dir)
634{
635 if (sgt->orig_nents) {
636 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
637 sg_free_table(sgt);
638 }
639}
640
641static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
642{
643 struct device *tx_dev, *rx_dev;
644 struct spi_transfer *xfer;
645 int ret;
646
647 if (!master->can_dma)
648 return 0;
649
650 tx_dev = &master->dma_tx->dev->device;
651 rx_dev = &master->dma_rx->dev->device;
652
653 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
654 if (!master->can_dma(master, msg->spi, xfer))
655 continue;
656
657 if (xfer->tx_buf != NULL) {
658 ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
659 (void *)xfer->tx_buf, xfer->len,
660 DMA_TO_DEVICE);
661 if (ret != 0)
662 return ret;
663 }
664
665 if (xfer->rx_buf != NULL) {
666 ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
667 xfer->rx_buf, xfer->len,
668 DMA_FROM_DEVICE);
669 if (ret != 0) {
670 spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
671 DMA_TO_DEVICE);
672 return ret;
673 }
674 }
675 }
676
677 master->cur_msg_mapped = true;
678
679 return 0;
680}
681
682static int spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
683{
684 struct spi_transfer *xfer;
685 struct device *tx_dev, *rx_dev;
686
687 if (!master->cur_msg_mapped || !master->can_dma)
688 return 0;
689
690 tx_dev = &master->dma_tx->dev->device;
691 rx_dev = &master->dma_rx->dev->device;
692
693 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
694 if (!master->can_dma(master, msg->spi, xfer))
695 continue;
696
697 spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
698 spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
699 }
700
701 return 0;
702}
703#else /* !CONFIG_HAS_DMA */
704static inline int __spi_map_msg(struct spi_master *master,
705 struct spi_message *msg)
706{
707 return 0;
708}
709
710static inline int spi_unmap_msg(struct spi_master *master,
711 struct spi_message *msg)
712{
713 return 0;
714}
715#endif /* !CONFIG_HAS_DMA */
716
717static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
718{
719 struct spi_transfer *xfer;
720 void *tmp;
721 unsigned int max_tx, max_rx;
722
723 if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
724 max_tx = 0;
725 max_rx = 0;
726
727 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
728 if ((master->flags & SPI_MASTER_MUST_TX) &&
729 !xfer->tx_buf)
730 max_tx = max(xfer->len, max_tx);
731 if ((master->flags & SPI_MASTER_MUST_RX) &&
732 !xfer->rx_buf)
733 max_rx = max(xfer->len, max_rx);
734 }
735
736 if (max_tx) {
737 tmp = krealloc(master->dummy_tx, max_tx,
738 GFP_KERNEL | GFP_DMA);
739 if (!tmp)
740 return -ENOMEM;
741 master->dummy_tx = tmp;
742 memset(tmp, 0, max_tx);
743 }
744
745 if (max_rx) {
746 tmp = krealloc(master->dummy_rx, max_rx,
747 GFP_KERNEL | GFP_DMA);
748 if (!tmp)
749 return -ENOMEM;
750 master->dummy_rx = tmp;
751 }
752
753 if (max_tx || max_rx) {
754 list_for_each_entry(xfer, &msg->transfers,
755 transfer_list) {
756 if (!xfer->tx_buf)
757 xfer->tx_buf = master->dummy_tx;
758 if (!xfer->rx_buf)
759 xfer->rx_buf = master->dummy_rx;
760 }
761 }
762 }
763
764 return __spi_map_msg(master, msg);
765}
766
767/*
768 * spi_transfer_one_message - Default implementation of transfer_one_message()
769 *
770 * This is a standard implementation of transfer_one_message() for
771 * drivers which impelment a transfer_one() operation. It provides
772 * standard handling of delays and chip select management.
773 */
774static int spi_transfer_one_message(struct spi_master *master,
775 struct spi_message *msg)
776{
777 struct spi_transfer *xfer;
778 bool keep_cs = false;
779 int ret = 0;
780 int ms = 1;
781
782 spi_set_cs(msg->spi, true);
783
784 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
785 trace_spi_transfer_start(msg, xfer);
786
787 reinit_completion(&master->xfer_completion);
788
789 ret = master->transfer_one(master, msg->spi, xfer);
790 if (ret < 0) {
791 dev_err(&msg->spi->dev,
792 "SPI transfer failed: %d\n", ret);
793 goto out;
794 }
795
796 if (ret > 0) {
797 ret = 0;
798 ms = xfer->len * 8 * 1000 / xfer->speed_hz;
799 ms += 10; /* some tolerance */
800
801 ms = wait_for_completion_timeout(&master->xfer_completion,
802 msecs_to_jiffies(ms));
803 }
804
805 if (ms == 0) {
806 dev_err(&msg->spi->dev, "SPI transfer timed out\n");
807 msg->status = -ETIMEDOUT;
808 }
809
810 trace_spi_transfer_stop(msg, xfer);
811
812 if (msg->status != -EINPROGRESS)
813 goto out;
814
815 if (xfer->delay_usecs)
816 udelay(xfer->delay_usecs);
817
818 if (xfer->cs_change) {
819 if (list_is_last(&xfer->transfer_list,
820 &msg->transfers)) {
821 keep_cs = true;
822 } else {
823 spi_set_cs(msg->spi, false);
824 udelay(10);
825 spi_set_cs(msg->spi, true);
826 }
827 }
828
829 msg->actual_length += xfer->len;
830 }
831
832out:
833 if (ret != 0 || !keep_cs)
834 spi_set_cs(msg->spi, false);
835
836 if (msg->status == -EINPROGRESS)
837 msg->status = ret;
838
839 spi_finalize_current_message(master);
840
841 return ret;
842}
843
844/**
845 * spi_finalize_current_transfer - report completion of a transfer
846 *
847 * Called by SPI drivers using the core transfer_one_message()
848 * implementation to notify it that the current interrupt driven
849 * transfer has finished and the next one may be scheduled.
850 */
851void spi_finalize_current_transfer(struct spi_master *master)
852{
853 complete(&master->xfer_completion);
854}
855EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
856
857/**
858 * spi_pump_messages - kthread work function which processes spi message queue
859 * @work: pointer to kthread work struct contained in the master struct
860 *
861 * This function checks if there is any spi message in the queue that
862 * needs processing and if so call out to the driver to initialize hardware
863 * and transfer each message.
864 *
865 */
866static void spi_pump_messages(struct kthread_work *work)
867{
868 struct spi_master *master =
869 container_of(work, struct spi_master, pump_messages);
870 unsigned long flags;
871 bool was_busy = false;
872 int ret;
873
874 /* Lock queue and check for queue work */
875 spin_lock_irqsave(&master->queue_lock, flags);
876 if (list_empty(&master->queue) || !master->running) {
877 if (!master->busy) {
878 spin_unlock_irqrestore(&master->queue_lock, flags);
879 return;
880 }
881 master->busy = false;
882 spin_unlock_irqrestore(&master->queue_lock, flags);
883 kfree(master->dummy_rx);
884 master->dummy_rx = NULL;
885 kfree(master->dummy_tx);
886 master->dummy_tx = NULL;
887 if (master->unprepare_transfer_hardware &&
888 master->unprepare_transfer_hardware(master))
889 dev_err(&master->dev,
890 "failed to unprepare transfer hardware\n");
891 if (master->auto_runtime_pm) {
892 pm_runtime_mark_last_busy(master->dev.parent);
893 pm_runtime_put_autosuspend(master->dev.parent);
894 }
895 trace_spi_master_idle(master);
896 return;
897 }
898
899 /* Make sure we are not already running a message */
900 if (master->cur_msg) {
901 spin_unlock_irqrestore(&master->queue_lock, flags);
902 return;
903 }
904 /* Extract head of queue */
905 master->cur_msg =
906 list_first_entry(&master->queue, struct spi_message, queue);
907
908 list_del_init(&master->cur_msg->queue);
909 if (master->busy)
910 was_busy = true;
911 else
912 master->busy = true;
913 spin_unlock_irqrestore(&master->queue_lock, flags);
914
915 if (!was_busy && master->auto_runtime_pm) {
916 ret = pm_runtime_get_sync(master->dev.parent);
917 if (ret < 0) {
918 dev_err(&master->dev, "Failed to power device: %d\n",
919 ret);
920 return;
921 }
922 }
923
924 if (!was_busy)
925 trace_spi_master_busy(master);
926
927 if (!was_busy && master->prepare_transfer_hardware) {
928 ret = master->prepare_transfer_hardware(master);
929 if (ret) {
930 dev_err(&master->dev,
931 "failed to prepare transfer hardware\n");
932
933 if (master->auto_runtime_pm)
934 pm_runtime_put(master->dev.parent);
935 return;
936 }
937 }
938
939 trace_spi_message_start(master->cur_msg);
940
941 if (master->prepare_message) {
942 ret = master->prepare_message(master, master->cur_msg);
943 if (ret) {
944 dev_err(&master->dev,
945 "failed to prepare message: %d\n", ret);
946 master->cur_msg->status = ret;
947 spi_finalize_current_message(master);
948 return;
949 }
950 master->cur_msg_prepared = true;
951 }
952
953 ret = spi_map_msg(master, master->cur_msg);
954 if (ret) {
955 master->cur_msg->status = ret;
956 spi_finalize_current_message(master);
957 return;
958 }
959
960 ret = master->transfer_one_message(master, master->cur_msg);
961 if (ret) {
962 dev_err(&master->dev,
963 "failed to transfer one message from queue\n");
964 return;
965 }
966}
967
968static int spi_init_queue(struct spi_master *master)
969{
970 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
971
972 INIT_LIST_HEAD(&master->queue);
973 spin_lock_init(&master->queue_lock);
974
975 master->running = false;
976 master->busy = false;
977
978 init_kthread_worker(&master->kworker);
979 master->kworker_task = kthread_run(kthread_worker_fn,
980 &master->kworker, "%s",
981 dev_name(&master->dev));
982 if (IS_ERR(master->kworker_task)) {
983 dev_err(&master->dev, "failed to create message pump task\n");
984 return -ENOMEM;
985 }
986 init_kthread_work(&master->pump_messages, spi_pump_messages);
987
988 /*
989 * Master config will indicate if this controller should run the
990 * message pump with high (realtime) priority to reduce the transfer
991 * latency on the bus by minimising the delay between a transfer
992 * request and the scheduling of the message pump thread. Without this
993 * setting the message pump thread will remain at default priority.
994 */
995 if (master->rt) {
996 dev_info(&master->dev,
997 "will run message pump with realtime priority\n");
998 sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m);
999 }
1000
1001 return 0;
1002}
1003
1004/**
1005 * spi_get_next_queued_message() - called by driver to check for queued
1006 * messages
1007 * @master: the master to check for queued messages
1008 *
1009 * If there are more messages in the queue, the next message is returned from
1010 * this call.
1011 */
1012struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1013{
1014 struct spi_message *next;
1015 unsigned long flags;
1016
1017 /* get a pointer to the next message, if any */
1018 spin_lock_irqsave(&master->queue_lock, flags);
1019 next = list_first_entry_or_null(&master->queue, struct spi_message,
1020 queue);
1021 spin_unlock_irqrestore(&master->queue_lock, flags);
1022
1023 return next;
1024}
1025EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1026
1027/**
1028 * spi_finalize_current_message() - the current message is complete
1029 * @master: the master to return the message to
1030 *
1031 * Called by the driver to notify the core that the message in the front of the
1032 * queue is complete and can be removed from the queue.
1033 */
1034void spi_finalize_current_message(struct spi_master *master)
1035{
1036 struct spi_message *mesg;
1037 unsigned long flags;
1038 int ret;
1039
1040 spin_lock_irqsave(&master->queue_lock, flags);
1041 mesg = master->cur_msg;
1042 master->cur_msg = NULL;
1043
1044 queue_kthread_work(&master->kworker, &master->pump_messages);
1045 spin_unlock_irqrestore(&master->queue_lock, flags);
1046
1047 spi_unmap_msg(master, mesg);
1048
1049 if (master->cur_msg_prepared && master->unprepare_message) {
1050 ret = master->unprepare_message(master, mesg);
1051 if (ret) {
1052 dev_err(&master->dev,
1053 "failed to unprepare message: %d\n", ret);
1054 }
1055 }
1056 master->cur_msg_prepared = false;
1057
1058 mesg->state = NULL;
1059 if (mesg->complete)
1060 mesg->complete(mesg->context);
1061
1062 trace_spi_message_done(mesg);
1063}
1064EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1065
1066static int spi_start_queue(struct spi_master *master)
1067{
1068 unsigned long flags;
1069
1070 spin_lock_irqsave(&master->queue_lock, flags);
1071
1072 if (master->running || master->busy) {
1073 spin_unlock_irqrestore(&master->queue_lock, flags);
1074 return -EBUSY;
1075 }
1076
1077 master->running = true;
1078 master->cur_msg = NULL;
1079 spin_unlock_irqrestore(&master->queue_lock, flags);
1080
1081 queue_kthread_work(&master->kworker, &master->pump_messages);
1082
1083 return 0;
1084}
1085
1086static int spi_stop_queue(struct spi_master *master)
1087{
1088 unsigned long flags;
1089 unsigned limit = 500;
1090 int ret = 0;
1091
1092 spin_lock_irqsave(&master->queue_lock, flags);
1093
1094 /*
1095 * This is a bit lame, but is optimized for the common execution path.
1096 * A wait_queue on the master->busy could be used, but then the common
1097 * execution path (pump_messages) would be required to call wake_up or
1098 * friends on every SPI message. Do this instead.
1099 */
1100 while ((!list_empty(&master->queue) || master->busy) && limit--) {
1101 spin_unlock_irqrestore(&master->queue_lock, flags);
1102 usleep_range(10000, 11000);
1103 spin_lock_irqsave(&master->queue_lock, flags);
1104 }
1105
1106 if (!list_empty(&master->queue) || master->busy)
1107 ret = -EBUSY;
1108 else
1109 master->running = false;
1110
1111 spin_unlock_irqrestore(&master->queue_lock, flags);
1112
1113 if (ret) {
1114 dev_warn(&master->dev,
1115 "could not stop message queue\n");
1116 return ret;
1117 }
1118 return ret;
1119}
1120
1121static int spi_destroy_queue(struct spi_master *master)
1122{
1123 int ret;
1124
1125 ret = spi_stop_queue(master);
1126
1127 /*
1128 * flush_kthread_worker will block until all work is done.
1129 * If the reason that stop_queue timed out is that the work will never
1130 * finish, then it does no good to call flush/stop thread, so
1131 * return anyway.
1132 */
1133 if (ret) {
1134 dev_err(&master->dev, "problem destroying queue\n");
1135 return ret;
1136 }
1137
1138 flush_kthread_worker(&master->kworker);
1139 kthread_stop(master->kworker_task);
1140
1141 return 0;
1142}
1143
1144/**
1145 * spi_queued_transfer - transfer function for queued transfers
1146 * @spi: spi device which is requesting transfer
1147 * @msg: spi message which is to handled is queued to driver queue
1148 */
1149static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1150{
1151 struct spi_master *master = spi->master;
1152 unsigned long flags;
1153
1154 spin_lock_irqsave(&master->queue_lock, flags);
1155
1156 if (!master->running) {
1157 spin_unlock_irqrestore(&master->queue_lock, flags);
1158 return -ESHUTDOWN;
1159 }
1160 msg->actual_length = 0;
1161 msg->status = -EINPROGRESS;
1162
1163 list_add_tail(&msg->queue, &master->queue);
1164 if (!master->busy)
1165 queue_kthread_work(&master->kworker, &master->pump_messages);
1166
1167 spin_unlock_irqrestore(&master->queue_lock, flags);
1168 return 0;
1169}
1170
1171static int spi_master_initialize_queue(struct spi_master *master)
1172{
1173 int ret;
1174
1175 master->transfer = spi_queued_transfer;
1176 if (!master->transfer_one_message)
1177 master->transfer_one_message = spi_transfer_one_message;
1178
1179 /* Initialize and start queue */
1180 ret = spi_init_queue(master);
1181 if (ret) {
1182 dev_err(&master->dev, "problem initializing queue\n");
1183 goto err_init_queue;
1184 }
1185 master->queued = true;
1186 ret = spi_start_queue(master);
1187 if (ret) {
1188 dev_err(&master->dev, "problem starting queue\n");
1189 goto err_start_queue;
1190 }
1191
1192 return 0;
1193
1194err_start_queue:
1195 spi_destroy_queue(master);
1196err_init_queue:
1197 return ret;
1198}
1199
1200/*-------------------------------------------------------------------------*/
1201
1202#if defined(CONFIG_OF)
1203/**
1204 * of_register_spi_devices() - Register child devices onto the SPI bus
1205 * @master: Pointer to spi_master device
1206 *
1207 * Registers an spi_device for each child node of master node which has a 'reg'
1208 * property.
1209 */
1210static void of_register_spi_devices(struct spi_master *master)
1211{
1212 struct spi_device *spi;
1213 struct device_node *nc;
1214 int rc;
1215 u32 value;
1216
1217 if (!master->dev.of_node)
1218 return;
1219
1220 for_each_available_child_of_node(master->dev.of_node, nc) {
1221 /* Alloc an spi_device */
1222 spi = spi_alloc_device(master);
1223 if (!spi) {
1224 dev_err(&master->dev, "spi_device alloc error for %s\n",
1225 nc->full_name);
1226 spi_dev_put(spi);
1227 continue;
1228 }
1229
1230 /* Select device driver */
1231 if (of_modalias_node(nc, spi->modalias,
1232 sizeof(spi->modalias)) < 0) {
1233 dev_err(&master->dev, "cannot find modalias for %s\n",
1234 nc->full_name);
1235 spi_dev_put(spi);
1236 continue;
1237 }
1238
1239 /* Device address */
1240 rc = of_property_read_u32(nc, "reg", &value);
1241 if (rc) {
1242 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1243 nc->full_name, rc);
1244 spi_dev_put(spi);
1245 continue;
1246 }
1247 spi->chip_select = value;
1248
1249 /* Mode (clock phase/polarity/etc.) */
1250 if (of_find_property(nc, "spi-cpha", NULL))
1251 spi->mode |= SPI_CPHA;
1252 if (of_find_property(nc, "spi-cpol", NULL))
1253 spi->mode |= SPI_CPOL;
1254 if (of_find_property(nc, "spi-cs-high", NULL))
1255 spi->mode |= SPI_CS_HIGH;
1256 if (of_find_property(nc, "spi-3wire", NULL))
1257 spi->mode |= SPI_3WIRE;
1258
1259 /* Device DUAL/QUAD mode */
1260 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1261 switch (value) {
1262 case 1:
1263 break;
1264 case 2:
1265 spi->mode |= SPI_TX_DUAL;
1266 break;
1267 case 4:
1268 spi->mode |= SPI_TX_QUAD;
1269 break;
1270 default:
1271 dev_err(&master->dev,
1272 "spi-tx-bus-width %d not supported\n",
1273 value);
1274 spi_dev_put(spi);
1275 continue;
1276 }
1277 }
1278
1279 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1280 switch (value) {
1281 case 1:
1282 break;
1283 case 2:
1284 spi->mode |= SPI_RX_DUAL;
1285 break;
1286 case 4:
1287 spi->mode |= SPI_RX_QUAD;
1288 break;
1289 default:
1290 dev_err(&master->dev,
1291 "spi-rx-bus-width %d not supported\n",
1292 value);
1293 spi_dev_put(spi);
1294 continue;
1295 }
1296 }
1297
1298 /* Device speed */
1299 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1300 if (rc) {
1301 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1302 nc->full_name, rc);
1303 spi_dev_put(spi);
1304 continue;
1305 }
1306 spi->max_speed_hz = value;
1307
1308 /* IRQ */
1309 spi->irq = irq_of_parse_and_map(nc, 0);
1310
1311 /* Store a pointer to the node in the device structure */
1312 of_node_get(nc);
1313 spi->dev.of_node = nc;
1314
1315 /* Register the new device */
1316 request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias);
1317 rc = spi_add_device(spi);
1318 if (rc) {
1319 dev_err(&master->dev, "spi_device register error %s\n",
1320 nc->full_name);
1321 spi_dev_put(spi);
1322 }
1323
1324 }
1325}
1326#else
1327static void of_register_spi_devices(struct spi_master *master) { }
1328#endif
1329
1330#ifdef CONFIG_ACPI
1331static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1332{
1333 struct spi_device *spi = data;
1334
1335 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1336 struct acpi_resource_spi_serialbus *sb;
1337
1338 sb = &ares->data.spi_serial_bus;
1339 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1340 spi->chip_select = sb->device_selection;
1341 spi->max_speed_hz = sb->connection_speed;
1342
1343 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1344 spi->mode |= SPI_CPHA;
1345 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1346 spi->mode |= SPI_CPOL;
1347 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1348 spi->mode |= SPI_CS_HIGH;
1349 }
1350 } else if (spi->irq < 0) {
1351 struct resource r;
1352
1353 if (acpi_dev_resource_interrupt(ares, 0, &r))
1354 spi->irq = r.start;
1355 }
1356
1357 /* Always tell the ACPI core to skip this resource */
1358 return 1;
1359}
1360
1361static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1362 void *data, void **return_value)
1363{
1364 struct spi_master *master = data;
1365 struct list_head resource_list;
1366 struct acpi_device *adev;
1367 struct spi_device *spi;
1368 int ret;
1369
1370 if (acpi_bus_get_device(handle, &adev))
1371 return AE_OK;
1372 if (acpi_bus_get_status(adev) || !adev->status.present)
1373 return AE_OK;
1374
1375 spi = spi_alloc_device(master);
1376 if (!spi) {
1377 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1378 dev_name(&adev->dev));
1379 return AE_NO_MEMORY;
1380 }
1381
1382 ACPI_COMPANION_SET(&spi->dev, adev);
1383 spi->irq = -1;
1384
1385 INIT_LIST_HEAD(&resource_list);
1386 ret = acpi_dev_get_resources(adev, &resource_list,
1387 acpi_spi_add_resource, spi);
1388 acpi_dev_free_resource_list(&resource_list);
1389
1390 if (ret < 0 || !spi->max_speed_hz) {
1391 spi_dev_put(spi);
1392 return AE_OK;
1393 }
1394
1395 adev->power.flags.ignore_parent = true;
1396 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
1397 if (spi_add_device(spi)) {
1398 adev->power.flags.ignore_parent = false;
1399 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1400 dev_name(&adev->dev));
1401 spi_dev_put(spi);
1402 }
1403
1404 return AE_OK;
1405}
1406
1407static void acpi_register_spi_devices(struct spi_master *master)
1408{
1409 acpi_status status;
1410 acpi_handle handle;
1411
1412 handle = ACPI_HANDLE(master->dev.parent);
1413 if (!handle)
1414 return;
1415
1416 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1417 acpi_spi_add_device, NULL,
1418 master, NULL);
1419 if (ACPI_FAILURE(status))
1420 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1421}
1422#else
1423static inline void acpi_register_spi_devices(struct spi_master *master) {}
1424#endif /* CONFIG_ACPI */
1425
1426static void spi_master_release(struct device *dev)
1427{
1428 struct spi_master *master;
1429
1430 master = container_of(dev, struct spi_master, dev);
1431 kfree(master);
1432}
1433
1434static struct class spi_master_class = {
1435 .name = "spi_master",
1436 .owner = THIS_MODULE,
1437 .dev_release = spi_master_release,
1438};
1439
1440
1441
1442/**
1443 * spi_alloc_master - allocate SPI master controller
1444 * @dev: the controller, possibly using the platform_bus
1445 * @size: how much zeroed driver-private data to allocate; the pointer to this
1446 * memory is in the driver_data field of the returned device,
1447 * accessible with spi_master_get_devdata().
1448 * Context: can sleep
1449 *
1450 * This call is used only by SPI master controller drivers, which are the
1451 * only ones directly touching chip registers. It's how they allocate
1452 * an spi_master structure, prior to calling spi_register_master().
1453 *
1454 * This must be called from context that can sleep. It returns the SPI
1455 * master structure on success, else NULL.
1456 *
1457 * The caller is responsible for assigning the bus number and initializing
1458 * the master's methods before calling spi_register_master(); and (after errors
1459 * adding the device) calling spi_master_put() and kfree() to prevent a memory
1460 * leak.
1461 */
1462struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
1463{
1464 struct spi_master *master;
1465
1466 if (!dev)
1467 return NULL;
1468
1469 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
1470 if (!master)
1471 return NULL;
1472
1473 device_initialize(&master->dev);
1474 master->bus_num = -1;
1475 master->num_chipselect = 1;
1476 master->dev.class = &spi_master_class;
1477 master->dev.parent = get_device(dev);
1478 spi_master_set_devdata(master, &master[1]);
1479
1480 return master;
1481}
1482EXPORT_SYMBOL_GPL(spi_alloc_master);
1483
1484#ifdef CONFIG_OF
1485static int of_spi_register_master(struct spi_master *master)
1486{
1487 int nb, i, *cs;
1488 struct device_node *np = master->dev.of_node;
1489
1490 if (!np)
1491 return 0;
1492
1493 nb = of_gpio_named_count(np, "cs-gpios");
1494 master->num_chipselect = max_t(int, nb, master->num_chipselect);
1495
1496 /* Return error only for an incorrectly formed cs-gpios property */
1497 if (nb == 0 || nb == -ENOENT)
1498 return 0;
1499 else if (nb < 0)
1500 return nb;
1501
1502 cs = devm_kzalloc(&master->dev,
1503 sizeof(int) * master->num_chipselect,
1504 GFP_KERNEL);
1505 master->cs_gpios = cs;
1506
1507 if (!master->cs_gpios)
1508 return -ENOMEM;
1509
1510 for (i = 0; i < master->num_chipselect; i++)
1511 cs[i] = -ENOENT;
1512
1513 for (i = 0; i < nb; i++)
1514 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1515
1516 return 0;
1517}
1518#else
1519static int of_spi_register_master(struct spi_master *master)
1520{
1521 return 0;
1522}
1523#endif
1524
1525/**
1526 * spi_register_master - register SPI master controller
1527 * @master: initialized master, originally from spi_alloc_master()
1528 * Context: can sleep
1529 *
1530 * SPI master controllers connect to their drivers using some non-SPI bus,
1531 * such as the platform bus. The final stage of probe() in that code
1532 * includes calling spi_register_master() to hook up to this SPI bus glue.
1533 *
1534 * SPI controllers use board specific (often SOC specific) bus numbers,
1535 * and board-specific addressing for SPI devices combines those numbers
1536 * with chip select numbers. Since SPI does not directly support dynamic
1537 * device identification, boards need configuration tables telling which
1538 * chip is at which address.
1539 *
1540 * This must be called from context that can sleep. It returns zero on
1541 * success, else a negative error code (dropping the master's refcount).
1542 * After a successful return, the caller is responsible for calling
1543 * spi_unregister_master().
1544 */
1545int spi_register_master(struct spi_master *master)
1546{
1547 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
1548 struct device *dev = master->dev.parent;
1549 struct boardinfo *bi;
1550 int status = -ENODEV;
1551 int dynamic = 0;
1552
1553 if (!dev)
1554 return -ENODEV;
1555
1556 status = of_spi_register_master(master);
1557 if (status)
1558 return status;
1559
1560 /* even if it's just one always-selected device, there must
1561 * be at least one chipselect
1562 */
1563 if (master->num_chipselect == 0)
1564 return -EINVAL;
1565
1566 if ((master->bus_num < 0) && master->dev.of_node)
1567 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1568
1569 /* convention: dynamically assigned bus IDs count down from the max */
1570 if (master->bus_num < 0) {
1571 /* FIXME switch to an IDR based scheme, something like
1572 * I2C now uses, so we can't run out of "dynamic" IDs
1573 */
1574 master->bus_num = atomic_dec_return(&dyn_bus_id);
1575 dynamic = 1;
1576 }
1577
1578 spin_lock_init(&master->bus_lock_spinlock);
1579 mutex_init(&master->bus_lock_mutex);
1580 master->bus_lock_flag = 0;
1581 init_completion(&master->xfer_completion);
1582 if (!master->max_dma_len)
1583 master->max_dma_len = INT_MAX;
1584
1585 /* register the device, then userspace will see it.
1586 * registration fails if the bus ID is in use.
1587 */
1588 dev_set_name(&master->dev, "spi%u", master->bus_num);
1589 status = device_add(&master->dev);
1590 if (status < 0)
1591 goto done;
1592 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
1593 dynamic ? " (dynamic)" : "");
1594
1595 /* If we're using a queued driver, start the queue */
1596 if (master->transfer)
1597 dev_info(dev, "master is unqueued, this is deprecated\n");
1598 else {
1599 status = spi_master_initialize_queue(master);
1600 if (status) {
1601 device_del(&master->dev);
1602 goto done;
1603 }
1604 }
1605
1606 mutex_lock(&board_lock);
1607 list_add_tail(&master->list, &spi_master_list);
1608 list_for_each_entry(bi, &board_list, list)
1609 spi_match_master_to_boardinfo(master, &bi->board_info);
1610 mutex_unlock(&board_lock);
1611
1612 /* Register devices from the device tree and ACPI */
1613 of_register_spi_devices(master);
1614 acpi_register_spi_devices(master);
1615done:
1616 return status;
1617}
1618EXPORT_SYMBOL_GPL(spi_register_master);
1619
1620static void devm_spi_unregister(struct device *dev, void *res)
1621{
1622 spi_unregister_master(*(struct spi_master **)res);
1623}
1624
1625/**
1626 * dev_spi_register_master - register managed SPI master controller
1627 * @dev: device managing SPI master
1628 * @master: initialized master, originally from spi_alloc_master()
1629 * Context: can sleep
1630 *
1631 * Register a SPI device as with spi_register_master() which will
1632 * automatically be unregister
1633 */
1634int devm_spi_register_master(struct device *dev, struct spi_master *master)
1635{
1636 struct spi_master **ptr;
1637 int ret;
1638
1639 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
1640 if (!ptr)
1641 return -ENOMEM;
1642
1643 ret = spi_register_master(master);
1644 if (!ret) {
1645 *ptr = master;
1646 devres_add(dev, ptr);
1647 } else {
1648 devres_free(ptr);
1649 }
1650
1651 return ret;
1652}
1653EXPORT_SYMBOL_GPL(devm_spi_register_master);
1654
1655static int __unregister(struct device *dev, void *null)
1656{
1657 spi_unregister_device(to_spi_device(dev));
1658 return 0;
1659}
1660
1661/**
1662 * spi_unregister_master - unregister SPI master controller
1663 * @master: the master being unregistered
1664 * Context: can sleep
1665 *
1666 * This call is used only by SPI master controller drivers, which are the
1667 * only ones directly touching chip registers.
1668 *
1669 * This must be called from context that can sleep.
1670 */
1671void spi_unregister_master(struct spi_master *master)
1672{
1673 int dummy;
1674
1675 if (master->queued) {
1676 if (spi_destroy_queue(master))
1677 dev_err(&master->dev, "queue remove failed\n");
1678 }
1679
1680 mutex_lock(&board_lock);
1681 list_del(&master->list);
1682 mutex_unlock(&board_lock);
1683
1684 dummy = device_for_each_child(&master->dev, NULL, __unregister);
1685 device_unregister(&master->dev);
1686}
1687EXPORT_SYMBOL_GPL(spi_unregister_master);
1688
1689int spi_master_suspend(struct spi_master *master)
1690{
1691 int ret;
1692
1693 /* Basically no-ops for non-queued masters */
1694 if (!master->queued)
1695 return 0;
1696
1697 ret = spi_stop_queue(master);
1698 if (ret)
1699 dev_err(&master->dev, "queue stop failed\n");
1700
1701 return ret;
1702}
1703EXPORT_SYMBOL_GPL(spi_master_suspend);
1704
1705int spi_master_resume(struct spi_master *master)
1706{
1707 int ret;
1708
1709 if (!master->queued)
1710 return 0;
1711
1712 ret = spi_start_queue(master);
1713 if (ret)
1714 dev_err(&master->dev, "queue restart failed\n");
1715
1716 return ret;
1717}
1718EXPORT_SYMBOL_GPL(spi_master_resume);
1719
1720static int __spi_master_match(struct device *dev, const void *data)
1721{
1722 struct spi_master *m;
1723 const u16 *bus_num = data;
1724
1725 m = container_of(dev, struct spi_master, dev);
1726 return m->bus_num == *bus_num;
1727}
1728
1729/**
1730 * spi_busnum_to_master - look up master associated with bus_num
1731 * @bus_num: the master's bus number
1732 * Context: can sleep
1733 *
1734 * This call may be used with devices that are registered after
1735 * arch init time. It returns a refcounted pointer to the relevant
1736 * spi_master (which the caller must release), or NULL if there is
1737 * no such master registered.
1738 */
1739struct spi_master *spi_busnum_to_master(u16 bus_num)
1740{
1741 struct device *dev;
1742 struct spi_master *master = NULL;
1743
1744 dev = class_find_device(&spi_master_class, NULL, &bus_num,
1745 __spi_master_match);
1746 if (dev)
1747 master = container_of(dev, struct spi_master, dev);
1748 /* reference got in class_find_device */
1749 return master;
1750}
1751EXPORT_SYMBOL_GPL(spi_busnum_to_master);
1752
1753
1754/*-------------------------------------------------------------------------*/
1755
1756/* Core methods for SPI master protocol drivers. Some of the
1757 * other core methods are currently defined as inline functions.
1758 */
1759
1760/**
1761 * spi_setup - setup SPI mode and clock rate
1762 * @spi: the device whose settings are being modified
1763 * Context: can sleep, and no requests are queued to the device
1764 *
1765 * SPI protocol drivers may need to update the transfer mode if the
1766 * device doesn't work with its default. They may likewise need
1767 * to update clock rates or word sizes from initial values. This function
1768 * changes those settings, and must be called from a context that can sleep.
1769 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
1770 * effect the next time the device is selected and data is transferred to
1771 * or from it. When this function returns, the spi device is deselected.
1772 *
1773 * Note that this call will fail if the protocol driver specifies an option
1774 * that the underlying controller or its driver does not support. For
1775 * example, not all hardware supports wire transfers using nine bit words,
1776 * LSB-first wire encoding, or active-high chipselects.
1777 */
1778int spi_setup(struct spi_device *spi)
1779{
1780 unsigned bad_bits, ugly_bits;
1781 int status = 0;
1782
1783 /* check mode to prevent that DUAL and QUAD set at the same time
1784 */
1785 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
1786 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
1787 dev_err(&spi->dev,
1788 "setup: can not select dual and quad at the same time\n");
1789 return -EINVAL;
1790 }
1791 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
1792 */
1793 if ((spi->mode & SPI_3WIRE) && (spi->mode &
1794 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
1795 return -EINVAL;
1796 /* help drivers fail *cleanly* when they need options
1797 * that aren't supported with their current master
1798 */
1799 bad_bits = spi->mode & ~spi->master->mode_bits;
1800 ugly_bits = bad_bits &
1801 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
1802 if (ugly_bits) {
1803 dev_warn(&spi->dev,
1804 "setup: ignoring unsupported mode bits %x\n",
1805 ugly_bits);
1806 spi->mode &= ~ugly_bits;
1807 bad_bits &= ~ugly_bits;
1808 }
1809 if (bad_bits) {
1810 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
1811 bad_bits);
1812 return -EINVAL;
1813 }
1814
1815 if (!spi->bits_per_word)
1816 spi->bits_per_word = 8;
1817
1818 if (!spi->max_speed_hz)
1819 spi->max_speed_hz = spi->master->max_speed_hz;
1820
1821 if (spi->master->setup)
1822 status = spi->master->setup(spi);
1823
1824 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
1825 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
1826 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
1827 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
1828 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
1829 (spi->mode & SPI_LOOP) ? "loopback, " : "",
1830 spi->bits_per_word, spi->max_speed_hz,
1831 status);
1832
1833 return status;
1834}
1835EXPORT_SYMBOL_GPL(spi_setup);
1836
1837static int __spi_validate(struct spi_device *spi, struct spi_message *message)
1838{
1839 struct spi_master *master = spi->master;
1840 struct spi_transfer *xfer;
1841 int w_size;
1842
1843 if (list_empty(&message->transfers))
1844 return -EINVAL;
1845
1846 /* Half-duplex links include original MicroWire, and ones with
1847 * only one data pin like SPI_3WIRE (switches direction) or where
1848 * either MOSI or MISO is missing. They can also be caused by
1849 * software limitations.
1850 */
1851 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
1852 || (spi->mode & SPI_3WIRE)) {
1853 unsigned flags = master->flags;
1854
1855 list_for_each_entry(xfer, &message->transfers, transfer_list) {
1856 if (xfer->rx_buf && xfer->tx_buf)
1857 return -EINVAL;
1858 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
1859 return -EINVAL;
1860 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
1861 return -EINVAL;
1862 }
1863 }
1864
1865 /**
1866 * Set transfer bits_per_word and max speed as spi device default if
1867 * it is not set for this transfer.
1868 * Set transfer tx_nbits and rx_nbits as single transfer default
1869 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
1870 */
1871 list_for_each_entry(xfer, &message->transfers, transfer_list) {
1872 message->frame_length += xfer->len;
1873 if (!xfer->bits_per_word)
1874 xfer->bits_per_word = spi->bits_per_word;
1875
1876 if (!xfer->speed_hz)
1877 xfer->speed_hz = spi->max_speed_hz;
1878
1879 if (master->max_speed_hz &&
1880 xfer->speed_hz > master->max_speed_hz)
1881 xfer->speed_hz = master->max_speed_hz;
1882
1883 if (master->bits_per_word_mask) {
1884 /* Only 32 bits fit in the mask */
1885 if (xfer->bits_per_word > 32)
1886 return -EINVAL;
1887 if (!(master->bits_per_word_mask &
1888 BIT(xfer->bits_per_word - 1)))
1889 return -EINVAL;
1890 }
1891
1892 /*
1893 * SPI transfer length should be multiple of SPI word size
1894 * where SPI word size should be power-of-two multiple
1895 */
1896 if (xfer->bits_per_word <= 8)
1897 w_size = 1;
1898 else if (xfer->bits_per_word <= 16)
1899 w_size = 2;
1900 else
1901 w_size = 4;
1902
1903 /* No partial transfers accepted */
1904 if (xfer->len % w_size)
1905 return -EINVAL;
1906
1907 if (xfer->speed_hz && master->min_speed_hz &&
1908 xfer->speed_hz < master->min_speed_hz)
1909 return -EINVAL;
1910
1911 if (xfer->tx_buf && !xfer->tx_nbits)
1912 xfer->tx_nbits = SPI_NBITS_SINGLE;
1913 if (xfer->rx_buf && !xfer->rx_nbits)
1914 xfer->rx_nbits = SPI_NBITS_SINGLE;
1915 /* check transfer tx/rx_nbits:
1916 * 1. check the value matches one of single, dual and quad
1917 * 2. check tx/rx_nbits match the mode in spi_device
1918 */
1919 if (xfer->tx_buf) {
1920 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
1921 xfer->tx_nbits != SPI_NBITS_DUAL &&
1922 xfer->tx_nbits != SPI_NBITS_QUAD)
1923 return -EINVAL;
1924 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
1925 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
1926 return -EINVAL;
1927 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
1928 !(spi->mode & SPI_TX_QUAD))
1929 return -EINVAL;
1930 }
1931 /* check transfer rx_nbits */
1932 if (xfer->rx_buf) {
1933 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
1934 xfer->rx_nbits != SPI_NBITS_DUAL &&
1935 xfer->rx_nbits != SPI_NBITS_QUAD)
1936 return -EINVAL;
1937 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
1938 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
1939 return -EINVAL;
1940 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
1941 !(spi->mode & SPI_RX_QUAD))
1942 return -EINVAL;
1943 }
1944 }
1945
1946 message->status = -EINPROGRESS;
1947
1948 return 0;
1949}
1950
1951static int __spi_async(struct spi_device *spi, struct spi_message *message)
1952{
1953 struct spi_master *master = spi->master;
1954
1955 message->spi = spi;
1956
1957 trace_spi_message_submit(message);
1958
1959 return master->transfer(spi, message);
1960}
1961
1962/**
1963 * spi_async - asynchronous SPI transfer
1964 * @spi: device with which data will be exchanged
1965 * @message: describes the data transfers, including completion callback
1966 * Context: any (irqs may be blocked, etc)
1967 *
1968 * This call may be used in_irq and other contexts which can't sleep,
1969 * as well as from task contexts which can sleep.
1970 *
1971 * The completion callback is invoked in a context which can't sleep.
1972 * Before that invocation, the value of message->status is undefined.
1973 * When the callback is issued, message->status holds either zero (to
1974 * indicate complete success) or a negative error code. After that
1975 * callback returns, the driver which issued the transfer request may
1976 * deallocate the associated memory; it's no longer in use by any SPI
1977 * core or controller driver code.
1978 *
1979 * Note that although all messages to a spi_device are handled in
1980 * FIFO order, messages may go to different devices in other orders.
1981 * Some device might be higher priority, or have various "hard" access
1982 * time requirements, for example.
1983 *
1984 * On detection of any fault during the transfer, processing of
1985 * the entire message is aborted, and the device is deselected.
1986 * Until returning from the associated message completion callback,
1987 * no other spi_message queued to that device will be processed.
1988 * (This rule applies equally to all the synchronous transfer calls,
1989 * which are wrappers around this core asynchronous primitive.)
1990 */
1991int spi_async(struct spi_device *spi, struct spi_message *message)
1992{
1993 struct spi_master *master = spi->master;
1994 int ret;
1995 unsigned long flags;
1996
1997 ret = __spi_validate(spi, message);
1998 if (ret != 0)
1999 return ret;
2000
2001 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2002
2003 if (master->bus_lock_flag)
2004 ret = -EBUSY;
2005 else
2006 ret = __spi_async(spi, message);
2007
2008 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2009
2010 return ret;
2011}
2012EXPORT_SYMBOL_GPL(spi_async);
2013
2014/**
2015 * spi_async_locked - version of spi_async with exclusive bus usage
2016 * @spi: device with which data will be exchanged
2017 * @message: describes the data transfers, including completion callback
2018 * Context: any (irqs may be blocked, etc)
2019 *
2020 * This call may be used in_irq and other contexts which can't sleep,
2021 * as well as from task contexts which can sleep.
2022 *
2023 * The completion callback is invoked in a context which can't sleep.
2024 * Before that invocation, the value of message->status is undefined.
2025 * When the callback is issued, message->status holds either zero (to
2026 * indicate complete success) or a negative error code. After that
2027 * callback returns, the driver which issued the transfer request may
2028 * deallocate the associated memory; it's no longer in use by any SPI
2029 * core or controller driver code.
2030 *
2031 * Note that although all messages to a spi_device are handled in
2032 * FIFO order, messages may go to different devices in other orders.
2033 * Some device might be higher priority, or have various "hard" access
2034 * time requirements, for example.
2035 *
2036 * On detection of any fault during the transfer, processing of
2037 * the entire message is aborted, and the device is deselected.
2038 * Until returning from the associated message completion callback,
2039 * no other spi_message queued to that device will be processed.
2040 * (This rule applies equally to all the synchronous transfer calls,
2041 * which are wrappers around this core asynchronous primitive.)
2042 */
2043int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2044{
2045 struct spi_master *master = spi->master;
2046 int ret;
2047 unsigned long flags;
2048
2049 ret = __spi_validate(spi, message);
2050 if (ret != 0)
2051 return ret;
2052
2053 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2054
2055 ret = __spi_async(spi, message);
2056
2057 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2058
2059 return ret;
2060
2061}
2062EXPORT_SYMBOL_GPL(spi_async_locked);
2063
2064
2065/*-------------------------------------------------------------------------*/
2066
2067/* Utility methods for SPI master protocol drivers, layered on
2068 * top of the core. Some other utility methods are defined as
2069 * inline functions.
2070 */
2071
2072static void spi_complete(void *arg)
2073{
2074 complete(arg);
2075}
2076
2077static int __spi_sync(struct spi_device *spi, struct spi_message *message,
2078 int bus_locked)
2079{
2080 DECLARE_COMPLETION_ONSTACK(done);
2081 int status;
2082 struct spi_master *master = spi->master;
2083
2084 message->complete = spi_complete;
2085 message->context = &done;
2086
2087 if (!bus_locked)
2088 mutex_lock(&master->bus_lock_mutex);
2089
2090 status = spi_async_locked(spi, message);
2091
2092 if (!bus_locked)
2093 mutex_unlock(&master->bus_lock_mutex);
2094
2095 if (status == 0) {
2096 wait_for_completion(&done);
2097 status = message->status;
2098 }
2099 message->context = NULL;
2100 return status;
2101}
2102
2103/**
2104 * spi_sync - blocking/synchronous SPI data transfers
2105 * @spi: device with which data will be exchanged
2106 * @message: describes the data transfers
2107 * Context: can sleep
2108 *
2109 * This call may only be used from a context that may sleep. The sleep
2110 * is non-interruptible, and has no timeout. Low-overhead controller
2111 * drivers may DMA directly into and out of the message buffers.
2112 *
2113 * Note that the SPI device's chip select is active during the message,
2114 * and then is normally disabled between messages. Drivers for some
2115 * frequently-used devices may want to minimize costs of selecting a chip,
2116 * by leaving it selected in anticipation that the next message will go
2117 * to the same chip. (That may increase power usage.)
2118 *
2119 * Also, the caller is guaranteeing that the memory associated with the
2120 * message will not be freed before this call returns.
2121 *
2122 * It returns zero on success, else a negative error code.
2123 */
2124int spi_sync(struct spi_device *spi, struct spi_message *message)
2125{
2126 return __spi_sync(spi, message, 0);
2127}
2128EXPORT_SYMBOL_GPL(spi_sync);
2129
2130/**
2131 * spi_sync_locked - version of spi_sync with exclusive bus usage
2132 * @spi: device with which data will be exchanged
2133 * @message: describes the data transfers
2134 * Context: can sleep
2135 *
2136 * This call may only be used from a context that may sleep. The sleep
2137 * is non-interruptible, and has no timeout. Low-overhead controller
2138 * drivers may DMA directly into and out of the message buffers.
2139 *
2140 * This call should be used by drivers that require exclusive access to the
2141 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
2142 * be released by a spi_bus_unlock call when the exclusive access is over.
2143 *
2144 * It returns zero on success, else a negative error code.
2145 */
2146int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2147{
2148 return __spi_sync(spi, message, 1);
2149}
2150EXPORT_SYMBOL_GPL(spi_sync_locked);
2151
2152/**
2153 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2154 * @master: SPI bus master that should be locked for exclusive bus access
2155 * Context: can sleep
2156 *
2157 * This call may only be used from a context that may sleep. The sleep
2158 * is non-interruptible, and has no timeout.
2159 *
2160 * This call should be used by drivers that require exclusive access to the
2161 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2162 * exclusive access is over. Data transfer must be done by spi_sync_locked
2163 * and spi_async_locked calls when the SPI bus lock is held.
2164 *
2165 * It returns zero on success, else a negative error code.
2166 */
2167int spi_bus_lock(struct spi_master *master)
2168{
2169 unsigned long flags;
2170
2171 mutex_lock(&master->bus_lock_mutex);
2172
2173 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2174 master->bus_lock_flag = 1;
2175 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2176
2177 /* mutex remains locked until spi_bus_unlock is called */
2178
2179 return 0;
2180}
2181EXPORT_SYMBOL_GPL(spi_bus_lock);
2182
2183/**
2184 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2185 * @master: SPI bus master that was locked for exclusive bus access
2186 * Context: can sleep
2187 *
2188 * This call may only be used from a context that may sleep. The sleep
2189 * is non-interruptible, and has no timeout.
2190 *
2191 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2192 * call.
2193 *
2194 * It returns zero on success, else a negative error code.
2195 */
2196int spi_bus_unlock(struct spi_master *master)
2197{
2198 master->bus_lock_flag = 0;
2199
2200 mutex_unlock(&master->bus_lock_mutex);
2201
2202 return 0;
2203}
2204EXPORT_SYMBOL_GPL(spi_bus_unlock);
2205
2206/* portable code must never pass more than 32 bytes */
2207#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
2208
2209static u8 *buf;
2210
2211/**
2212 * spi_write_then_read - SPI synchronous write followed by read
2213 * @spi: device with which data will be exchanged
2214 * @txbuf: data to be written (need not be dma-safe)
2215 * @n_tx: size of txbuf, in bytes
2216 * @rxbuf: buffer into which data will be read (need not be dma-safe)
2217 * @n_rx: size of rxbuf, in bytes
2218 * Context: can sleep
2219 *
2220 * This performs a half duplex MicroWire style transaction with the
2221 * device, sending txbuf and then reading rxbuf. The return value
2222 * is zero for success, else a negative errno status code.
2223 * This call may only be used from a context that may sleep.
2224 *
2225 * Parameters to this routine are always copied using a small buffer;
2226 * portable code should never use this for more than 32 bytes.
2227 * Performance-sensitive or bulk transfer code should instead use
2228 * spi_{async,sync}() calls with dma-safe buffers.
2229 */
2230int spi_write_then_read(struct spi_device *spi,
2231 const void *txbuf, unsigned n_tx,
2232 void *rxbuf, unsigned n_rx)
2233{
2234 static DEFINE_MUTEX(lock);
2235
2236 int status;
2237 struct spi_message message;
2238 struct spi_transfer x[2];
2239 u8 *local_buf;
2240
2241 /* Use preallocated DMA-safe buffer if we can. We can't avoid
2242 * copying here, (as a pure convenience thing), but we can
2243 * keep heap costs out of the hot path unless someone else is
2244 * using the pre-allocated buffer or the transfer is too large.
2245 */
2246 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
2247 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
2248 GFP_KERNEL | GFP_DMA);
2249 if (!local_buf)
2250 return -ENOMEM;
2251 } else {
2252 local_buf = buf;
2253 }
2254
2255 spi_message_init(&message);
2256 memset(x, 0, sizeof(x));
2257 if (n_tx) {
2258 x[0].len = n_tx;
2259 spi_message_add_tail(&x[0], &message);
2260 }
2261 if (n_rx) {
2262 x[1].len = n_rx;
2263 spi_message_add_tail(&x[1], &message);
2264 }
2265
2266 memcpy(local_buf, txbuf, n_tx);
2267 x[0].tx_buf = local_buf;
2268 x[1].rx_buf = local_buf + n_tx;
2269
2270 /* do the i/o */
2271 status = spi_sync(spi, &message);
2272 if (status == 0)
2273 memcpy(rxbuf, x[1].rx_buf, n_rx);
2274
2275 if (x[0].tx_buf == buf)
2276 mutex_unlock(&lock);
2277 else
2278 kfree(local_buf);
2279
2280 return status;
2281}
2282EXPORT_SYMBOL_GPL(spi_write_then_read);
2283
2284/*-------------------------------------------------------------------------*/
2285
2286static int __init spi_init(void)
2287{
2288 int status;
2289
2290 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
2291 if (!buf) {
2292 status = -ENOMEM;
2293 goto err0;
2294 }
2295
2296 status = bus_register(&spi_bus_type);
2297 if (status < 0)
2298 goto err1;
2299
2300 status = class_register(&spi_master_class);
2301 if (status < 0)
2302 goto err2;
2303 return 0;
2304
2305err2:
2306 bus_unregister(&spi_bus_type);
2307err1:
2308 kfree(buf);
2309 buf = NULL;
2310err0:
2311 return status;
2312}
2313
2314/* board_info is normally registered in arch_initcall(),
2315 * but even essential drivers wait till later
2316 *
2317 * REVISIT only boardinfo really needs static linking. the rest (device and
2318 * driver registration) _could_ be dynamically linked (modular) ... costs
2319 * include needing to have boardinfo data structures be much more public.
2320 */
2321postcore_initcall(spi_init);
2322