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spi: mediatek: Don't modify spi_transfer when transfer.
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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/spi/spi-mem.h>
32#include <linux/of_gpio.h>
33#include <linux/pm_runtime.h>
34#include <linux/pm_domain.h>
35#include <linux/property.h>
36#include <linux/export.h>
37#include <linux/sched/rt.h>
38#include <uapi/linux/sched/types.h>
39#include <linux/delay.h>
40#include <linux/kthread.h>
41#include <linux/ioport.h>
42#include <linux/acpi.h>
43#include <linux/highmem.h>
44#include <linux/idr.h>
45#include <linux/platform_data/x86/apple.h>
46
47#define CREATE_TRACE_POINTS
48#include <trace/events/spi.h>
49
50#include "internals.h"
51
52static DEFINE_IDR(spi_master_idr);
53
54static void spidev_release(struct device *dev)
55{
56 struct spi_device *spi = to_spi_device(dev);
57
58 /* spi controllers may cleanup for released devices */
59 if (spi->controller->cleanup)
60 spi->controller->cleanup(spi);
61
62 spi_controller_put(spi->controller);
63 kfree(spi);
64}
65
66static ssize_t
67modalias_show(struct device *dev, struct device_attribute *a, char *buf)
68{
69 const struct spi_device *spi = to_spi_device(dev);
70 int len;
71
72 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
73 if (len != -ENODEV)
74 return len;
75
76 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
77}
78static DEVICE_ATTR_RO(modalias);
79
80#define SPI_STATISTICS_ATTRS(field, file) \
81static ssize_t spi_controller_##field##_show(struct device *dev, \
82 struct device_attribute *attr, \
83 char *buf) \
84{ \
85 struct spi_controller *ctlr = container_of(dev, \
86 struct spi_controller, dev); \
87 return spi_statistics_##field##_show(&ctlr->statistics, buf); \
88} \
89static struct device_attribute dev_attr_spi_controller_##field = { \
90 .attr = { .name = file, .mode = 0444 }, \
91 .show = spi_controller_##field##_show, \
92}; \
93static ssize_t spi_device_##field##_show(struct device *dev, \
94 struct device_attribute *attr, \
95 char *buf) \
96{ \
97 struct spi_device *spi = to_spi_device(dev); \
98 return spi_statistics_##field##_show(&spi->statistics, buf); \
99} \
100static struct device_attribute dev_attr_spi_device_##field = { \
101 .attr = { .name = file, .mode = 0444 }, \
102 .show = spi_device_##field##_show, \
103}
104
105#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
106static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
107 char *buf) \
108{ \
109 unsigned long flags; \
110 ssize_t len; \
111 spin_lock_irqsave(&stat->lock, flags); \
112 len = sprintf(buf, format_string, stat->field); \
113 spin_unlock_irqrestore(&stat->lock, flags); \
114 return len; \
115} \
116SPI_STATISTICS_ATTRS(name, file)
117
118#define SPI_STATISTICS_SHOW(field, format_string) \
119 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
120 field, format_string)
121
122SPI_STATISTICS_SHOW(messages, "%lu");
123SPI_STATISTICS_SHOW(transfers, "%lu");
124SPI_STATISTICS_SHOW(errors, "%lu");
125SPI_STATISTICS_SHOW(timedout, "%lu");
126
127SPI_STATISTICS_SHOW(spi_sync, "%lu");
128SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
129SPI_STATISTICS_SHOW(spi_async, "%lu");
130
131SPI_STATISTICS_SHOW(bytes, "%llu");
132SPI_STATISTICS_SHOW(bytes_rx, "%llu");
133SPI_STATISTICS_SHOW(bytes_tx, "%llu");
134
135#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
136 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
137 "transfer_bytes_histo_" number, \
138 transfer_bytes_histo[index], "%lu")
139SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
140SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
141SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
142SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
143SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
144SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
145SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
146SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
147SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
148SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
149SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
150SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
151SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
152SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
153SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
154SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
155SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
156
157SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
158
159static struct attribute *spi_dev_attrs[] = {
160 &dev_attr_modalias.attr,
161 NULL,
162};
163
164static const struct attribute_group spi_dev_group = {
165 .attrs = spi_dev_attrs,
166};
167
168static struct attribute *spi_device_statistics_attrs[] = {
169 &dev_attr_spi_device_messages.attr,
170 &dev_attr_spi_device_transfers.attr,
171 &dev_attr_spi_device_errors.attr,
172 &dev_attr_spi_device_timedout.attr,
173 &dev_attr_spi_device_spi_sync.attr,
174 &dev_attr_spi_device_spi_sync_immediate.attr,
175 &dev_attr_spi_device_spi_async.attr,
176 &dev_attr_spi_device_bytes.attr,
177 &dev_attr_spi_device_bytes_rx.attr,
178 &dev_attr_spi_device_bytes_tx.attr,
179 &dev_attr_spi_device_transfer_bytes_histo0.attr,
180 &dev_attr_spi_device_transfer_bytes_histo1.attr,
181 &dev_attr_spi_device_transfer_bytes_histo2.attr,
182 &dev_attr_spi_device_transfer_bytes_histo3.attr,
183 &dev_attr_spi_device_transfer_bytes_histo4.attr,
184 &dev_attr_spi_device_transfer_bytes_histo5.attr,
185 &dev_attr_spi_device_transfer_bytes_histo6.attr,
186 &dev_attr_spi_device_transfer_bytes_histo7.attr,
187 &dev_attr_spi_device_transfer_bytes_histo8.attr,
188 &dev_attr_spi_device_transfer_bytes_histo9.attr,
189 &dev_attr_spi_device_transfer_bytes_histo10.attr,
190 &dev_attr_spi_device_transfer_bytes_histo11.attr,
191 &dev_attr_spi_device_transfer_bytes_histo12.attr,
192 &dev_attr_spi_device_transfer_bytes_histo13.attr,
193 &dev_attr_spi_device_transfer_bytes_histo14.attr,
194 &dev_attr_spi_device_transfer_bytes_histo15.attr,
195 &dev_attr_spi_device_transfer_bytes_histo16.attr,
196 &dev_attr_spi_device_transfers_split_maxsize.attr,
197 NULL,
198};
199
200static const struct attribute_group spi_device_statistics_group = {
201 .name = "statistics",
202 .attrs = spi_device_statistics_attrs,
203};
204
205static const struct attribute_group *spi_dev_groups[] = {
206 &spi_dev_group,
207 &spi_device_statistics_group,
208 NULL,
209};
210
211static struct attribute *spi_controller_statistics_attrs[] = {
212 &dev_attr_spi_controller_messages.attr,
213 &dev_attr_spi_controller_transfers.attr,
214 &dev_attr_spi_controller_errors.attr,
215 &dev_attr_spi_controller_timedout.attr,
216 &dev_attr_spi_controller_spi_sync.attr,
217 &dev_attr_spi_controller_spi_sync_immediate.attr,
218 &dev_attr_spi_controller_spi_async.attr,
219 &dev_attr_spi_controller_bytes.attr,
220 &dev_attr_spi_controller_bytes_rx.attr,
221 &dev_attr_spi_controller_bytes_tx.attr,
222 &dev_attr_spi_controller_transfer_bytes_histo0.attr,
223 &dev_attr_spi_controller_transfer_bytes_histo1.attr,
224 &dev_attr_spi_controller_transfer_bytes_histo2.attr,
225 &dev_attr_spi_controller_transfer_bytes_histo3.attr,
226 &dev_attr_spi_controller_transfer_bytes_histo4.attr,
227 &dev_attr_spi_controller_transfer_bytes_histo5.attr,
228 &dev_attr_spi_controller_transfer_bytes_histo6.attr,
229 &dev_attr_spi_controller_transfer_bytes_histo7.attr,
230 &dev_attr_spi_controller_transfer_bytes_histo8.attr,
231 &dev_attr_spi_controller_transfer_bytes_histo9.attr,
232 &dev_attr_spi_controller_transfer_bytes_histo10.attr,
233 &dev_attr_spi_controller_transfer_bytes_histo11.attr,
234 &dev_attr_spi_controller_transfer_bytes_histo12.attr,
235 &dev_attr_spi_controller_transfer_bytes_histo13.attr,
236 &dev_attr_spi_controller_transfer_bytes_histo14.attr,
237 &dev_attr_spi_controller_transfer_bytes_histo15.attr,
238 &dev_attr_spi_controller_transfer_bytes_histo16.attr,
239 &dev_attr_spi_controller_transfers_split_maxsize.attr,
240 NULL,
241};
242
243static const struct attribute_group spi_controller_statistics_group = {
244 .name = "statistics",
245 .attrs = spi_controller_statistics_attrs,
246};
247
248static const struct attribute_group *spi_master_groups[] = {
249 &spi_controller_statistics_group,
250 NULL,
251};
252
253void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
254 struct spi_transfer *xfer,
255 struct spi_controller *ctlr)
256{
257 unsigned long flags;
258 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
259
260 if (l2len < 0)
261 l2len = 0;
262
263 spin_lock_irqsave(&stats->lock, flags);
264
265 stats->transfers++;
266 stats->transfer_bytes_histo[l2len]++;
267
268 stats->bytes += xfer->len;
269 if ((xfer->tx_buf) &&
270 (xfer->tx_buf != ctlr->dummy_tx))
271 stats->bytes_tx += xfer->len;
272 if ((xfer->rx_buf) &&
273 (xfer->rx_buf != ctlr->dummy_rx))
274 stats->bytes_rx += xfer->len;
275
276 spin_unlock_irqrestore(&stats->lock, flags);
277}
278EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
279
280/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
281 * and the sysfs version makes coldplug work too.
282 */
283
284static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
285 const struct spi_device *sdev)
286{
287 while (id->name[0]) {
288 if (!strcmp(sdev->modalias, id->name))
289 return id;
290 id++;
291 }
292 return NULL;
293}
294
295const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
296{
297 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
298
299 return spi_match_id(sdrv->id_table, sdev);
300}
301EXPORT_SYMBOL_GPL(spi_get_device_id);
302
303static int spi_match_device(struct device *dev, struct device_driver *drv)
304{
305 const struct spi_device *spi = to_spi_device(dev);
306 const struct spi_driver *sdrv = to_spi_driver(drv);
307
308 /* Attempt an OF style match */
309 if (of_driver_match_device(dev, drv))
310 return 1;
311
312 /* Then try ACPI */
313 if (acpi_driver_match_device(dev, drv))
314 return 1;
315
316 if (sdrv->id_table)
317 return !!spi_match_id(sdrv->id_table, spi);
318
319 return strcmp(spi->modalias, drv->name) == 0;
320}
321
322static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
323{
324 const struct spi_device *spi = to_spi_device(dev);
325 int rc;
326
327 rc = acpi_device_uevent_modalias(dev, env);
328 if (rc != -ENODEV)
329 return rc;
330
331 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
332}
333
334struct bus_type spi_bus_type = {
335 .name = "spi",
336 .dev_groups = spi_dev_groups,
337 .match = spi_match_device,
338 .uevent = spi_uevent,
339};
340EXPORT_SYMBOL_GPL(spi_bus_type);
341
342
343static int spi_drv_probe(struct device *dev)
344{
345 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
346 struct spi_device *spi = to_spi_device(dev);
347 int ret;
348
349 ret = of_clk_set_defaults(dev->of_node, false);
350 if (ret)
351 return ret;
352
353 if (dev->of_node) {
354 spi->irq = of_irq_get(dev->of_node, 0);
355 if (spi->irq == -EPROBE_DEFER)
356 return -EPROBE_DEFER;
357 if (spi->irq < 0)
358 spi->irq = 0;
359 }
360
361 ret = dev_pm_domain_attach(dev, true);
362 if (ret)
363 return ret;
364
365 ret = sdrv->probe(spi);
366 if (ret)
367 dev_pm_domain_detach(dev, true);
368
369 return ret;
370}
371
372static int spi_drv_remove(struct device *dev)
373{
374 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
375 int ret;
376
377 ret = sdrv->remove(to_spi_device(dev));
378 dev_pm_domain_detach(dev, true);
379
380 return ret;
381}
382
383static void spi_drv_shutdown(struct device *dev)
384{
385 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
386
387 sdrv->shutdown(to_spi_device(dev));
388}
389
390/**
391 * __spi_register_driver - register a SPI driver
392 * @owner: owner module of the driver to register
393 * @sdrv: the driver to register
394 * Context: can sleep
395 *
396 * Return: zero on success, else a negative error code.
397 */
398int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
399{
400 sdrv->driver.owner = owner;
401 sdrv->driver.bus = &spi_bus_type;
402 if (sdrv->probe)
403 sdrv->driver.probe = spi_drv_probe;
404 if (sdrv->remove)
405 sdrv->driver.remove = spi_drv_remove;
406 if (sdrv->shutdown)
407 sdrv->driver.shutdown = spi_drv_shutdown;
408 return driver_register(&sdrv->driver);
409}
410EXPORT_SYMBOL_GPL(__spi_register_driver);
411
412/*-------------------------------------------------------------------------*/
413
414/* SPI devices should normally not be created by SPI device drivers; that
415 * would make them board-specific. Similarly with SPI controller drivers.
416 * Device registration normally goes into like arch/.../mach.../board-YYY.c
417 * with other readonly (flashable) information about mainboard devices.
418 */
419
420struct boardinfo {
421 struct list_head list;
422 struct spi_board_info board_info;
423};
424
425static LIST_HEAD(board_list);
426static LIST_HEAD(spi_controller_list);
427
428/*
429 * Used to protect add/del opertion for board_info list and
430 * spi_controller list, and their matching process
431 * also used to protect object of type struct idr
432 */
433static DEFINE_MUTEX(board_lock);
434
435/**
436 * spi_alloc_device - Allocate a new SPI device
437 * @ctlr: Controller to which device is connected
438 * Context: can sleep
439 *
440 * Allows a driver to allocate and initialize a spi_device without
441 * registering it immediately. This allows a driver to directly
442 * fill the spi_device with device parameters before calling
443 * spi_add_device() on it.
444 *
445 * Caller is responsible to call spi_add_device() on the returned
446 * spi_device structure to add it to the SPI controller. If the caller
447 * needs to discard the spi_device without adding it, then it should
448 * call spi_dev_put() on it.
449 *
450 * Return: a pointer to the new device, or NULL.
451 */
452struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
453{
454 struct spi_device *spi;
455
456 if (!spi_controller_get(ctlr))
457 return NULL;
458
459 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
460 if (!spi) {
461 spi_controller_put(ctlr);
462 return NULL;
463 }
464
465 spi->master = spi->controller = ctlr;
466 spi->dev.parent = &ctlr->dev;
467 spi->dev.bus = &spi_bus_type;
468 spi->dev.release = spidev_release;
469 spi->cs_gpio = -ENOENT;
470
471 spin_lock_init(&spi->statistics.lock);
472
473 device_initialize(&spi->dev);
474 return spi;
475}
476EXPORT_SYMBOL_GPL(spi_alloc_device);
477
478static void spi_dev_set_name(struct spi_device *spi)
479{
480 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
481
482 if (adev) {
483 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
484 return;
485 }
486
487 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
488 spi->chip_select);
489}
490
491static int spi_dev_check(struct device *dev, void *data)
492{
493 struct spi_device *spi = to_spi_device(dev);
494 struct spi_device *new_spi = data;
495
496 if (spi->controller == new_spi->controller &&
497 spi->chip_select == new_spi->chip_select)
498 return -EBUSY;
499 return 0;
500}
501
502/**
503 * spi_add_device - Add spi_device allocated with spi_alloc_device
504 * @spi: spi_device to register
505 *
506 * Companion function to spi_alloc_device. Devices allocated with
507 * spi_alloc_device can be added onto the spi bus with this function.
508 *
509 * Return: 0 on success; negative errno on failure
510 */
511int spi_add_device(struct spi_device *spi)
512{
513 static DEFINE_MUTEX(spi_add_lock);
514 struct spi_controller *ctlr = spi->controller;
515 struct device *dev = ctlr->dev.parent;
516 int status;
517
518 /* Chipselects are numbered 0..max; validate. */
519 if (spi->chip_select >= ctlr->num_chipselect) {
520 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
521 ctlr->num_chipselect);
522 return -EINVAL;
523 }
524
525 /* Set the bus ID string */
526 spi_dev_set_name(spi);
527
528 /* We need to make sure there's no other device with this
529 * chipselect **BEFORE** we call setup(), else we'll trash
530 * its configuration. Lock against concurrent add() calls.
531 */
532 mutex_lock(&spi_add_lock);
533
534 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
535 if (status) {
536 dev_err(dev, "chipselect %d already in use\n",
537 spi->chip_select);
538 goto done;
539 }
540
541 if (ctlr->cs_gpios)
542 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
543
544 /* Drivers may modify this initial i/o setup, but will
545 * normally rely on the device being setup. Devices
546 * using SPI_CS_HIGH can't coexist well otherwise...
547 */
548 status = spi_setup(spi);
549 if (status < 0) {
550 dev_err(dev, "can't setup %s, status %d\n",
551 dev_name(&spi->dev), status);
552 goto done;
553 }
554
555 /* Device may be bound to an active driver when this returns */
556 status = device_add(&spi->dev);
557 if (status < 0)
558 dev_err(dev, "can't add %s, status %d\n",
559 dev_name(&spi->dev), status);
560 else
561 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
562
563done:
564 mutex_unlock(&spi_add_lock);
565 return status;
566}
567EXPORT_SYMBOL_GPL(spi_add_device);
568
569/**
570 * spi_new_device - instantiate one new SPI device
571 * @ctlr: Controller to which device is connected
572 * @chip: Describes the SPI device
573 * Context: can sleep
574 *
575 * On typical mainboards, this is purely internal; and it's not needed
576 * after board init creates the hard-wired devices. Some development
577 * platforms may not be able to use spi_register_board_info though, and
578 * this is exported so that for example a USB or parport based adapter
579 * driver could add devices (which it would learn about out-of-band).
580 *
581 * Return: the new device, or NULL.
582 */
583struct spi_device *spi_new_device(struct spi_controller *ctlr,
584 struct spi_board_info *chip)
585{
586 struct spi_device *proxy;
587 int status;
588
589 /* NOTE: caller did any chip->bus_num checks necessary.
590 *
591 * Also, unless we change the return value convention to use
592 * error-or-pointer (not NULL-or-pointer), troubleshootability
593 * suggests syslogged diagnostics are best here (ugh).
594 */
595
596 proxy = spi_alloc_device(ctlr);
597 if (!proxy)
598 return NULL;
599
600 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
601
602 proxy->chip_select = chip->chip_select;
603 proxy->max_speed_hz = chip->max_speed_hz;
604 proxy->mode = chip->mode;
605 proxy->irq = chip->irq;
606 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
607 proxy->dev.platform_data = (void *) chip->platform_data;
608 proxy->controller_data = chip->controller_data;
609 proxy->controller_state = NULL;
610
611 if (chip->properties) {
612 status = device_add_properties(&proxy->dev, chip->properties);
613 if (status) {
614 dev_err(&ctlr->dev,
615 "failed to add properties to '%s': %d\n",
616 chip->modalias, status);
617 goto err_dev_put;
618 }
619 }
620
621 status = spi_add_device(proxy);
622 if (status < 0)
623 goto err_remove_props;
624
625 return proxy;
626
627err_remove_props:
628 if (chip->properties)
629 device_remove_properties(&proxy->dev);
630err_dev_put:
631 spi_dev_put(proxy);
632 return NULL;
633}
634EXPORT_SYMBOL_GPL(spi_new_device);
635
636/**
637 * spi_unregister_device - unregister a single SPI device
638 * @spi: spi_device to unregister
639 *
640 * Start making the passed SPI device vanish. Normally this would be handled
641 * by spi_unregister_controller().
642 */
643void spi_unregister_device(struct spi_device *spi)
644{
645 if (!spi)
646 return;
647
648 if (spi->dev.of_node) {
649 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
650 of_node_put(spi->dev.of_node);
651 }
652 if (ACPI_COMPANION(&spi->dev))
653 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
654 device_unregister(&spi->dev);
655}
656EXPORT_SYMBOL_GPL(spi_unregister_device);
657
658static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
659 struct spi_board_info *bi)
660{
661 struct spi_device *dev;
662
663 if (ctlr->bus_num != bi->bus_num)
664 return;
665
666 dev = spi_new_device(ctlr, bi);
667 if (!dev)
668 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
669 bi->modalias);
670}
671
672/**
673 * spi_register_board_info - register SPI devices for a given board
674 * @info: array of chip descriptors
675 * @n: how many descriptors are provided
676 * Context: can sleep
677 *
678 * Board-specific early init code calls this (probably during arch_initcall)
679 * with segments of the SPI device table. Any device nodes are created later,
680 * after the relevant parent SPI controller (bus_num) is defined. We keep
681 * this table of devices forever, so that reloading a controller driver will
682 * not make Linux forget about these hard-wired devices.
683 *
684 * Other code can also call this, e.g. a particular add-on board might provide
685 * SPI devices through its expansion connector, so code initializing that board
686 * would naturally declare its SPI devices.
687 *
688 * The board info passed can safely be __initdata ... but be careful of
689 * any embedded pointers (platform_data, etc), they're copied as-is.
690 * Device properties are deep-copied though.
691 *
692 * Return: zero on success, else a negative error code.
693 */
694int spi_register_board_info(struct spi_board_info const *info, unsigned n)
695{
696 struct boardinfo *bi;
697 int i;
698
699 if (!n)
700 return 0;
701
702 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
703 if (!bi)
704 return -ENOMEM;
705
706 for (i = 0; i < n; i++, bi++, info++) {
707 struct spi_controller *ctlr;
708
709 memcpy(&bi->board_info, info, sizeof(*info));
710 if (info->properties) {
711 bi->board_info.properties =
712 property_entries_dup(info->properties);
713 if (IS_ERR(bi->board_info.properties))
714 return PTR_ERR(bi->board_info.properties);
715 }
716
717 mutex_lock(&board_lock);
718 list_add_tail(&bi->list, &board_list);
719 list_for_each_entry(ctlr, &spi_controller_list, list)
720 spi_match_controller_to_boardinfo(ctlr,
721 &bi->board_info);
722 mutex_unlock(&board_lock);
723 }
724
725 return 0;
726}
727
728/*-------------------------------------------------------------------------*/
729
730static void spi_set_cs(struct spi_device *spi, bool enable)
731{
732 if (spi->mode & SPI_CS_HIGH)
733 enable = !enable;
734
735 if (gpio_is_valid(spi->cs_gpio)) {
736 gpio_set_value(spi->cs_gpio, !enable);
737 /* Some SPI masters need both GPIO CS & slave_select */
738 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
739 spi->controller->set_cs)
740 spi->controller->set_cs(spi, !enable);
741 } else if (spi->controller->set_cs) {
742 spi->controller->set_cs(spi, !enable);
743 }
744}
745
746#ifdef CONFIG_HAS_DMA
747int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
748 struct sg_table *sgt, void *buf, size_t len,
749 enum dma_data_direction dir)
750{
751 const bool vmalloced_buf = is_vmalloc_addr(buf);
752 unsigned int max_seg_size = dma_get_max_seg_size(dev);
753#ifdef CONFIG_HIGHMEM
754 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
755 (unsigned long)buf < (PKMAP_BASE +
756 (LAST_PKMAP * PAGE_SIZE)));
757#else
758 const bool kmap_buf = false;
759#endif
760 int desc_len;
761 int sgs;
762 struct page *vm_page;
763 struct scatterlist *sg;
764 void *sg_buf;
765 size_t min;
766 int i, ret;
767
768 if (vmalloced_buf || kmap_buf) {
769 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
770 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
771 } else if (virt_addr_valid(buf)) {
772 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
773 sgs = DIV_ROUND_UP(len, desc_len);
774 } else {
775 return -EINVAL;
776 }
777
778 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
779 if (ret != 0)
780 return ret;
781
782 sg = &sgt->sgl[0];
783 for (i = 0; i < sgs; i++) {
784
785 if (vmalloced_buf || kmap_buf) {
786 /*
787 * Next scatterlist entry size is the minimum between
788 * the desc_len and the remaining buffer length that
789 * fits in a page.
790 */
791 min = min_t(size_t, desc_len,
792 min_t(size_t, len,
793 PAGE_SIZE - offset_in_page(buf)));
794 if (vmalloced_buf)
795 vm_page = vmalloc_to_page(buf);
796 else
797 vm_page = kmap_to_page(buf);
798 if (!vm_page) {
799 sg_free_table(sgt);
800 return -ENOMEM;
801 }
802 sg_set_page(sg, vm_page,
803 min, offset_in_page(buf));
804 } else {
805 min = min_t(size_t, len, desc_len);
806 sg_buf = buf;
807 sg_set_buf(sg, sg_buf, min);
808 }
809
810 buf += min;
811 len -= min;
812 sg = sg_next(sg);
813 }
814
815 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
816 if (!ret)
817 ret = -ENOMEM;
818 if (ret < 0) {
819 sg_free_table(sgt);
820 return ret;
821 }
822
823 sgt->nents = ret;
824
825 return 0;
826}
827
828void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
829 struct sg_table *sgt, enum dma_data_direction dir)
830{
831 if (sgt->orig_nents) {
832 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
833 sg_free_table(sgt);
834 }
835}
836
837static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
838{
839 struct device *tx_dev, *rx_dev;
840 struct spi_transfer *xfer;
841 int ret;
842
843 if (!ctlr->can_dma)
844 return 0;
845
846 if (ctlr->dma_tx)
847 tx_dev = ctlr->dma_tx->device->dev;
848 else
849 tx_dev = ctlr->dev.parent;
850
851 if (ctlr->dma_rx)
852 rx_dev = ctlr->dma_rx->device->dev;
853 else
854 rx_dev = ctlr->dev.parent;
855
856 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
857 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
858 continue;
859
860 if (xfer->tx_buf != NULL) {
861 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
862 (void *)xfer->tx_buf, xfer->len,
863 DMA_TO_DEVICE);
864 if (ret != 0)
865 return ret;
866 }
867
868 if (xfer->rx_buf != NULL) {
869 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
870 xfer->rx_buf, xfer->len,
871 DMA_FROM_DEVICE);
872 if (ret != 0) {
873 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
874 DMA_TO_DEVICE);
875 return ret;
876 }
877 }
878 }
879
880 ctlr->cur_msg_mapped = true;
881
882 return 0;
883}
884
885static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
886{
887 struct spi_transfer *xfer;
888 struct device *tx_dev, *rx_dev;
889
890 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
891 return 0;
892
893 if (ctlr->dma_tx)
894 tx_dev = ctlr->dma_tx->device->dev;
895 else
896 tx_dev = ctlr->dev.parent;
897
898 if (ctlr->dma_rx)
899 rx_dev = ctlr->dma_rx->device->dev;
900 else
901 rx_dev = ctlr->dev.parent;
902
903 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
904 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
905 continue;
906
907 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
908 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
909 }
910
911 return 0;
912}
913#else /* !CONFIG_HAS_DMA */
914static inline int __spi_map_msg(struct spi_controller *ctlr,
915 struct spi_message *msg)
916{
917 return 0;
918}
919
920static inline int __spi_unmap_msg(struct spi_controller *ctlr,
921 struct spi_message *msg)
922{
923 return 0;
924}
925#endif /* !CONFIG_HAS_DMA */
926
927static inline int spi_unmap_msg(struct spi_controller *ctlr,
928 struct spi_message *msg)
929{
930 struct spi_transfer *xfer;
931
932 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
933 /*
934 * Restore the original value of tx_buf or rx_buf if they are
935 * NULL.
936 */
937 if (xfer->tx_buf == ctlr->dummy_tx)
938 xfer->tx_buf = NULL;
939 if (xfer->rx_buf == ctlr->dummy_rx)
940 xfer->rx_buf = NULL;
941 }
942
943 return __spi_unmap_msg(ctlr, msg);
944}
945
946static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
947{
948 struct spi_transfer *xfer;
949 void *tmp;
950 unsigned int max_tx, max_rx;
951
952 if (ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) {
953 max_tx = 0;
954 max_rx = 0;
955
956 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
957 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
958 !xfer->tx_buf)
959 max_tx = max(xfer->len, max_tx);
960 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
961 !xfer->rx_buf)
962 max_rx = max(xfer->len, max_rx);
963 }
964
965 if (max_tx) {
966 tmp = krealloc(ctlr->dummy_tx, max_tx,
967 GFP_KERNEL | GFP_DMA);
968 if (!tmp)
969 return -ENOMEM;
970 ctlr->dummy_tx = tmp;
971 memset(tmp, 0, max_tx);
972 }
973
974 if (max_rx) {
975 tmp = krealloc(ctlr->dummy_rx, max_rx,
976 GFP_KERNEL | GFP_DMA);
977 if (!tmp)
978 return -ENOMEM;
979 ctlr->dummy_rx = tmp;
980 }
981
982 if (max_tx || max_rx) {
983 list_for_each_entry(xfer, &msg->transfers,
984 transfer_list) {
985 if (!xfer->tx_buf)
986 xfer->tx_buf = ctlr->dummy_tx;
987 if (!xfer->rx_buf)
988 xfer->rx_buf = ctlr->dummy_rx;
989 }
990 }
991 }
992
993 return __spi_map_msg(ctlr, msg);
994}
995
996/*
997 * spi_transfer_one_message - Default implementation of transfer_one_message()
998 *
999 * This is a standard implementation of transfer_one_message() for
1000 * drivers which implement a transfer_one() operation. It provides
1001 * standard handling of delays and chip select management.
1002 */
1003static int spi_transfer_one_message(struct spi_controller *ctlr,
1004 struct spi_message *msg)
1005{
1006 struct spi_transfer *xfer;
1007 bool keep_cs = false;
1008 int ret = 0;
1009 unsigned long long ms = 1;
1010 struct spi_statistics *statm = &ctlr->statistics;
1011 struct spi_statistics *stats = &msg->spi->statistics;
1012
1013 spi_set_cs(msg->spi, true);
1014
1015 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1016 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1017
1018 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1019 trace_spi_transfer_start(msg, xfer);
1020
1021 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1022 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1023
1024 if (xfer->tx_buf || xfer->rx_buf) {
1025 reinit_completion(&ctlr->xfer_completion);
1026
1027 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1028 if (ret < 0) {
1029 SPI_STATISTICS_INCREMENT_FIELD(statm,
1030 errors);
1031 SPI_STATISTICS_INCREMENT_FIELD(stats,
1032 errors);
1033 dev_err(&msg->spi->dev,
1034 "SPI transfer failed: %d\n", ret);
1035 goto out;
1036 }
1037
1038 if (ret > 0) {
1039 ret = 0;
1040 ms = 8LL * 1000LL * xfer->len;
1041 do_div(ms, xfer->speed_hz);
1042 ms += ms + 200; /* some tolerance */
1043
1044 if (ms > UINT_MAX)
1045 ms = UINT_MAX;
1046
1047 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1048 msecs_to_jiffies(ms));
1049 }
1050
1051 if (ms == 0) {
1052 SPI_STATISTICS_INCREMENT_FIELD(statm,
1053 timedout);
1054 SPI_STATISTICS_INCREMENT_FIELD(stats,
1055 timedout);
1056 dev_err(&msg->spi->dev,
1057 "SPI transfer timed out\n");
1058 msg->status = -ETIMEDOUT;
1059 }
1060 } else {
1061 if (xfer->len)
1062 dev_err(&msg->spi->dev,
1063 "Bufferless transfer has length %u\n",
1064 xfer->len);
1065 }
1066
1067 trace_spi_transfer_stop(msg, xfer);
1068
1069 if (msg->status != -EINPROGRESS)
1070 goto out;
1071
1072 if (xfer->delay_usecs) {
1073 u16 us = xfer->delay_usecs;
1074
1075 if (us <= 10)
1076 udelay(us);
1077 else
1078 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1079 }
1080
1081 if (xfer->cs_change) {
1082 if (list_is_last(&xfer->transfer_list,
1083 &msg->transfers)) {
1084 keep_cs = true;
1085 } else {
1086 spi_set_cs(msg->spi, false);
1087 udelay(10);
1088 spi_set_cs(msg->spi, true);
1089 }
1090 }
1091
1092 msg->actual_length += xfer->len;
1093 }
1094
1095out:
1096 if (ret != 0 || !keep_cs)
1097 spi_set_cs(msg->spi, false);
1098
1099 if (msg->status == -EINPROGRESS)
1100 msg->status = ret;
1101
1102 if (msg->status && ctlr->handle_err)
1103 ctlr->handle_err(ctlr, msg);
1104
1105 spi_res_release(ctlr, msg);
1106
1107 spi_finalize_current_message(ctlr);
1108
1109 return ret;
1110}
1111
1112/**
1113 * spi_finalize_current_transfer - report completion of a transfer
1114 * @ctlr: the controller reporting completion
1115 *
1116 * Called by SPI drivers using the core transfer_one_message()
1117 * implementation to notify it that the current interrupt driven
1118 * transfer has finished and the next one may be scheduled.
1119 */
1120void spi_finalize_current_transfer(struct spi_controller *ctlr)
1121{
1122 complete(&ctlr->xfer_completion);
1123}
1124EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1125
1126/**
1127 * __spi_pump_messages - function which processes spi message queue
1128 * @ctlr: controller to process queue for
1129 * @in_kthread: true if we are in the context of the message pump thread
1130 *
1131 * This function checks if there is any spi message in the queue that
1132 * needs processing and if so call out to the driver to initialize hardware
1133 * and transfer each message.
1134 *
1135 * Note that it is called both from the kthread itself and also from
1136 * inside spi_sync(); the queue extraction handling at the top of the
1137 * function should deal with this safely.
1138 */
1139static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1140{
1141 unsigned long flags;
1142 bool was_busy = false;
1143 int ret;
1144
1145 /* Lock queue */
1146 spin_lock_irqsave(&ctlr->queue_lock, flags);
1147
1148 /* Make sure we are not already running a message */
1149 if (ctlr->cur_msg) {
1150 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1151 return;
1152 }
1153
1154 /* If another context is idling the device then defer */
1155 if (ctlr->idling) {
1156 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1157 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1158 return;
1159 }
1160
1161 /* Check if the queue is idle */
1162 if (list_empty(&ctlr->queue) || !ctlr->running) {
1163 if (!ctlr->busy) {
1164 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1165 return;
1166 }
1167
1168 /* Only do teardown in the thread */
1169 if (!in_kthread) {
1170 kthread_queue_work(&ctlr->kworker,
1171 &ctlr->pump_messages);
1172 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1173 return;
1174 }
1175
1176 ctlr->busy = false;
1177 ctlr->idling = true;
1178 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1179
1180 kfree(ctlr->dummy_rx);
1181 ctlr->dummy_rx = NULL;
1182 kfree(ctlr->dummy_tx);
1183 ctlr->dummy_tx = NULL;
1184 if (ctlr->unprepare_transfer_hardware &&
1185 ctlr->unprepare_transfer_hardware(ctlr))
1186 dev_err(&ctlr->dev,
1187 "failed to unprepare transfer hardware\n");
1188 if (ctlr->auto_runtime_pm) {
1189 pm_runtime_mark_last_busy(ctlr->dev.parent);
1190 pm_runtime_put_autosuspend(ctlr->dev.parent);
1191 }
1192 trace_spi_controller_idle(ctlr);
1193
1194 spin_lock_irqsave(&ctlr->queue_lock, flags);
1195 ctlr->idling = false;
1196 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1197 return;
1198 }
1199
1200 /* Extract head of queue */
1201 ctlr->cur_msg =
1202 list_first_entry(&ctlr->queue, struct spi_message, queue);
1203
1204 list_del_init(&ctlr->cur_msg->queue);
1205 if (ctlr->busy)
1206 was_busy = true;
1207 else
1208 ctlr->busy = true;
1209 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1210
1211 mutex_lock(&ctlr->io_mutex);
1212
1213 if (!was_busy && ctlr->auto_runtime_pm) {
1214 ret = pm_runtime_get_sync(ctlr->dev.parent);
1215 if (ret < 0) {
1216 pm_runtime_put_noidle(ctlr->dev.parent);
1217 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1218 ret);
1219 mutex_unlock(&ctlr->io_mutex);
1220 return;
1221 }
1222 }
1223
1224 if (!was_busy)
1225 trace_spi_controller_busy(ctlr);
1226
1227 if (!was_busy && ctlr->prepare_transfer_hardware) {
1228 ret = ctlr->prepare_transfer_hardware(ctlr);
1229 if (ret) {
1230 dev_err(&ctlr->dev,
1231 "failed to prepare transfer hardware\n");
1232
1233 if (ctlr->auto_runtime_pm)
1234 pm_runtime_put(ctlr->dev.parent);
1235 mutex_unlock(&ctlr->io_mutex);
1236 return;
1237 }
1238 }
1239
1240 trace_spi_message_start(ctlr->cur_msg);
1241
1242 if (ctlr->prepare_message) {
1243 ret = ctlr->prepare_message(ctlr, ctlr->cur_msg);
1244 if (ret) {
1245 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1246 ret);
1247 ctlr->cur_msg->status = ret;
1248 spi_finalize_current_message(ctlr);
1249 goto out;
1250 }
1251 ctlr->cur_msg_prepared = true;
1252 }
1253
1254 ret = spi_map_msg(ctlr, ctlr->cur_msg);
1255 if (ret) {
1256 ctlr->cur_msg->status = ret;
1257 spi_finalize_current_message(ctlr);
1258 goto out;
1259 }
1260
1261 ret = ctlr->transfer_one_message(ctlr, ctlr->cur_msg);
1262 if (ret) {
1263 dev_err(&ctlr->dev,
1264 "failed to transfer one message from queue\n");
1265 goto out;
1266 }
1267
1268out:
1269 mutex_unlock(&ctlr->io_mutex);
1270
1271 /* Prod the scheduler in case transfer_one() was busy waiting */
1272 if (!ret)
1273 cond_resched();
1274}
1275
1276/**
1277 * spi_pump_messages - kthread work function which processes spi message queue
1278 * @work: pointer to kthread work struct contained in the controller struct
1279 */
1280static void spi_pump_messages(struct kthread_work *work)
1281{
1282 struct spi_controller *ctlr =
1283 container_of(work, struct spi_controller, pump_messages);
1284
1285 __spi_pump_messages(ctlr, true);
1286}
1287
1288static int spi_init_queue(struct spi_controller *ctlr)
1289{
1290 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1291
1292 ctlr->running = false;
1293 ctlr->busy = false;
1294
1295 kthread_init_worker(&ctlr->kworker);
1296 ctlr->kworker_task = kthread_run(kthread_worker_fn, &ctlr->kworker,
1297 "%s", dev_name(&ctlr->dev));
1298 if (IS_ERR(ctlr->kworker_task)) {
1299 dev_err(&ctlr->dev, "failed to create message pump task\n");
1300 return PTR_ERR(ctlr->kworker_task);
1301 }
1302 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1303
1304 /*
1305 * Controller config will indicate if this controller should run the
1306 * message pump with high (realtime) priority to reduce the transfer
1307 * latency on the bus by minimising the delay between a transfer
1308 * request and the scheduling of the message pump thread. Without this
1309 * setting the message pump thread will remain at default priority.
1310 */
1311 if (ctlr->rt) {
1312 dev_info(&ctlr->dev,
1313 "will run message pump with realtime priority\n");
1314 sched_setscheduler(ctlr->kworker_task, SCHED_FIFO, &param);
1315 }
1316
1317 return 0;
1318}
1319
1320/**
1321 * spi_get_next_queued_message() - called by driver to check for queued
1322 * messages
1323 * @ctlr: the controller to check for queued messages
1324 *
1325 * If there are more messages in the queue, the next message is returned from
1326 * this call.
1327 *
1328 * Return: the next message in the queue, else NULL if the queue is empty.
1329 */
1330struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1331{
1332 struct spi_message *next;
1333 unsigned long flags;
1334
1335 /* get a pointer to the next message, if any */
1336 spin_lock_irqsave(&ctlr->queue_lock, flags);
1337 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1338 queue);
1339 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1340
1341 return next;
1342}
1343EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1344
1345/**
1346 * spi_finalize_current_message() - the current message is complete
1347 * @ctlr: the controller to return the message to
1348 *
1349 * Called by the driver to notify the core that the message in the front of the
1350 * queue is complete and can be removed from the queue.
1351 */
1352void spi_finalize_current_message(struct spi_controller *ctlr)
1353{
1354 struct spi_message *mesg;
1355 unsigned long flags;
1356 int ret;
1357
1358 spin_lock_irqsave(&ctlr->queue_lock, flags);
1359 mesg = ctlr->cur_msg;
1360 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1361
1362 spi_unmap_msg(ctlr, mesg);
1363
1364 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1365 ret = ctlr->unprepare_message(ctlr, mesg);
1366 if (ret) {
1367 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1368 ret);
1369 }
1370 }
1371
1372 spin_lock_irqsave(&ctlr->queue_lock, flags);
1373 ctlr->cur_msg = NULL;
1374 ctlr->cur_msg_prepared = false;
1375 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1376 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1377
1378 trace_spi_message_done(mesg);
1379
1380 mesg->state = NULL;
1381 if (mesg->complete)
1382 mesg->complete(mesg->context);
1383}
1384EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1385
1386static int spi_start_queue(struct spi_controller *ctlr)
1387{
1388 unsigned long flags;
1389
1390 spin_lock_irqsave(&ctlr->queue_lock, flags);
1391
1392 if (ctlr->running || ctlr->busy) {
1393 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1394 return -EBUSY;
1395 }
1396
1397 ctlr->running = true;
1398 ctlr->cur_msg = NULL;
1399 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1400
1401 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1402
1403 return 0;
1404}
1405
1406static int spi_stop_queue(struct spi_controller *ctlr)
1407{
1408 unsigned long flags;
1409 unsigned limit = 500;
1410 int ret = 0;
1411
1412 spin_lock_irqsave(&ctlr->queue_lock, flags);
1413
1414 /*
1415 * This is a bit lame, but is optimized for the common execution path.
1416 * A wait_queue on the ctlr->busy could be used, but then the common
1417 * execution path (pump_messages) would be required to call wake_up or
1418 * friends on every SPI message. Do this instead.
1419 */
1420 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1421 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1422 usleep_range(10000, 11000);
1423 spin_lock_irqsave(&ctlr->queue_lock, flags);
1424 }
1425
1426 if (!list_empty(&ctlr->queue) || ctlr->busy)
1427 ret = -EBUSY;
1428 else
1429 ctlr->running = false;
1430
1431 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1432
1433 if (ret) {
1434 dev_warn(&ctlr->dev, "could not stop message queue\n");
1435 return ret;
1436 }
1437 return ret;
1438}
1439
1440static int spi_destroy_queue(struct spi_controller *ctlr)
1441{
1442 int ret;
1443
1444 ret = spi_stop_queue(ctlr);
1445
1446 /*
1447 * kthread_flush_worker will block until all work is done.
1448 * If the reason that stop_queue timed out is that the work will never
1449 * finish, then it does no good to call flush/stop thread, so
1450 * return anyway.
1451 */
1452 if (ret) {
1453 dev_err(&ctlr->dev, "problem destroying queue\n");
1454 return ret;
1455 }
1456
1457 kthread_flush_worker(&ctlr->kworker);
1458 kthread_stop(ctlr->kworker_task);
1459
1460 return 0;
1461}
1462
1463static int __spi_queued_transfer(struct spi_device *spi,
1464 struct spi_message *msg,
1465 bool need_pump)
1466{
1467 struct spi_controller *ctlr = spi->controller;
1468 unsigned long flags;
1469
1470 spin_lock_irqsave(&ctlr->queue_lock, flags);
1471
1472 if (!ctlr->running) {
1473 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1474 return -ESHUTDOWN;
1475 }
1476 msg->actual_length = 0;
1477 msg->status = -EINPROGRESS;
1478
1479 list_add_tail(&msg->queue, &ctlr->queue);
1480 if (!ctlr->busy && need_pump)
1481 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1482
1483 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1484 return 0;
1485}
1486
1487/**
1488 * spi_queued_transfer - transfer function for queued transfers
1489 * @spi: spi device which is requesting transfer
1490 * @msg: spi message which is to handled is queued to driver queue
1491 *
1492 * Return: zero on success, else a negative error code.
1493 */
1494static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1495{
1496 return __spi_queued_transfer(spi, msg, true);
1497}
1498
1499static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1500{
1501 int ret;
1502
1503 ctlr->transfer = spi_queued_transfer;
1504 if (!ctlr->transfer_one_message)
1505 ctlr->transfer_one_message = spi_transfer_one_message;
1506
1507 /* Initialize and start queue */
1508 ret = spi_init_queue(ctlr);
1509 if (ret) {
1510 dev_err(&ctlr->dev, "problem initializing queue\n");
1511 goto err_init_queue;
1512 }
1513 ctlr->queued = true;
1514 ret = spi_start_queue(ctlr);
1515 if (ret) {
1516 dev_err(&ctlr->dev, "problem starting queue\n");
1517 goto err_start_queue;
1518 }
1519
1520 return 0;
1521
1522err_start_queue:
1523 spi_destroy_queue(ctlr);
1524err_init_queue:
1525 return ret;
1526}
1527
1528/**
1529 * spi_flush_queue - Send all pending messages in the queue from the callers'
1530 * context
1531 * @ctlr: controller to process queue for
1532 *
1533 * This should be used when one wants to ensure all pending messages have been
1534 * sent before doing something. Is used by the spi-mem code to make sure SPI
1535 * memory operations do not preempt regular SPI transfers that have been queued
1536 * before the spi-mem operation.
1537 */
1538void spi_flush_queue(struct spi_controller *ctlr)
1539{
1540 if (ctlr->transfer == spi_queued_transfer)
1541 __spi_pump_messages(ctlr, false);
1542}
1543
1544/*-------------------------------------------------------------------------*/
1545
1546#if defined(CONFIG_OF)
1547static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1548 struct device_node *nc)
1549{
1550 u32 value;
1551 int rc;
1552
1553 /* Mode (clock phase/polarity/etc.) */
1554 if (of_property_read_bool(nc, "spi-cpha"))
1555 spi->mode |= SPI_CPHA;
1556 if (of_property_read_bool(nc, "spi-cpol"))
1557 spi->mode |= SPI_CPOL;
1558 if (of_property_read_bool(nc, "spi-cs-high"))
1559 spi->mode |= SPI_CS_HIGH;
1560 if (of_property_read_bool(nc, "spi-3wire"))
1561 spi->mode |= SPI_3WIRE;
1562 if (of_property_read_bool(nc, "spi-lsb-first"))
1563 spi->mode |= SPI_LSB_FIRST;
1564
1565 /* Device DUAL/QUAD mode */
1566 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1567 switch (value) {
1568 case 1:
1569 break;
1570 case 2:
1571 spi->mode |= SPI_TX_DUAL;
1572 break;
1573 case 4:
1574 spi->mode |= SPI_TX_QUAD;
1575 break;
1576 default:
1577 dev_warn(&ctlr->dev,
1578 "spi-tx-bus-width %d not supported\n",
1579 value);
1580 break;
1581 }
1582 }
1583
1584 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1585 switch (value) {
1586 case 1:
1587 break;
1588 case 2:
1589 spi->mode |= SPI_RX_DUAL;
1590 break;
1591 case 4:
1592 spi->mode |= SPI_RX_QUAD;
1593 break;
1594 default:
1595 dev_warn(&ctlr->dev,
1596 "spi-rx-bus-width %d not supported\n",
1597 value);
1598 break;
1599 }
1600 }
1601
1602 if (spi_controller_is_slave(ctlr)) {
1603 if (strcmp(nc->name, "slave")) {
1604 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
1605 nc);
1606 return -EINVAL;
1607 }
1608 return 0;
1609 }
1610
1611 /* Device address */
1612 rc = of_property_read_u32(nc, "reg", &value);
1613 if (rc) {
1614 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
1615 nc, rc);
1616 return rc;
1617 }
1618 spi->chip_select = value;
1619
1620 /* Device speed */
1621 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1622 if (rc) {
1623 dev_err(&ctlr->dev,
1624 "%pOF has no valid 'spi-max-frequency' property (%d)\n", nc, rc);
1625 return rc;
1626 }
1627 spi->max_speed_hz = value;
1628
1629 return 0;
1630}
1631
1632static struct spi_device *
1633of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
1634{
1635 struct spi_device *spi;
1636 int rc;
1637
1638 /* Alloc an spi_device */
1639 spi = spi_alloc_device(ctlr);
1640 if (!spi) {
1641 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
1642 rc = -ENOMEM;
1643 goto err_out;
1644 }
1645
1646 /* Select device driver */
1647 rc = of_modalias_node(nc, spi->modalias,
1648 sizeof(spi->modalias));
1649 if (rc < 0) {
1650 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
1651 goto err_out;
1652 }
1653
1654 rc = of_spi_parse_dt(ctlr, spi, nc);
1655 if (rc)
1656 goto err_out;
1657
1658 /* Store a pointer to the node in the device structure */
1659 of_node_get(nc);
1660 spi->dev.of_node = nc;
1661
1662 /* Register the new device */
1663 rc = spi_add_device(spi);
1664 if (rc) {
1665 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
1666 goto err_of_node_put;
1667 }
1668
1669 return spi;
1670
1671err_of_node_put:
1672 of_node_put(nc);
1673err_out:
1674 spi_dev_put(spi);
1675 return ERR_PTR(rc);
1676}
1677
1678/**
1679 * of_register_spi_devices() - Register child devices onto the SPI bus
1680 * @ctlr: Pointer to spi_controller device
1681 *
1682 * Registers an spi_device for each child node of controller node which
1683 * represents a valid SPI slave.
1684 */
1685static void of_register_spi_devices(struct spi_controller *ctlr)
1686{
1687 struct spi_device *spi;
1688 struct device_node *nc;
1689
1690 if (!ctlr->dev.of_node)
1691 return;
1692
1693 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
1694 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1695 continue;
1696 spi = of_register_spi_device(ctlr, nc);
1697 if (IS_ERR(spi)) {
1698 dev_warn(&ctlr->dev,
1699 "Failed to create SPI device for %pOF\n", nc);
1700 of_node_clear_flag(nc, OF_POPULATED);
1701 }
1702 }
1703}
1704#else
1705static void of_register_spi_devices(struct spi_controller *ctlr) { }
1706#endif
1707
1708#ifdef CONFIG_ACPI
1709static void acpi_spi_parse_apple_properties(struct spi_device *spi)
1710{
1711 struct acpi_device *dev = ACPI_COMPANION(&spi->dev);
1712 const union acpi_object *obj;
1713
1714 if (!x86_apple_machine)
1715 return;
1716
1717 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
1718 && obj->buffer.length >= 4)
1719 spi->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
1720
1721 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
1722 && obj->buffer.length == 8)
1723 spi->bits_per_word = *(u64 *)obj->buffer.pointer;
1724
1725 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
1726 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
1727 spi->mode |= SPI_LSB_FIRST;
1728
1729 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
1730 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
1731 spi->mode |= SPI_CPOL;
1732
1733 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
1734 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
1735 spi->mode |= SPI_CPHA;
1736}
1737
1738static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1739{
1740 struct spi_device *spi = data;
1741 struct spi_controller *ctlr = spi->controller;
1742
1743 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1744 struct acpi_resource_spi_serialbus *sb;
1745
1746 sb = &ares->data.spi_serial_bus;
1747 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1748 /*
1749 * ACPI DeviceSelection numbering is handled by the
1750 * host controller driver in Windows and can vary
1751 * from driver to driver. In Linux we always expect
1752 * 0 .. max - 1 so we need to ask the driver to
1753 * translate between the two schemes.
1754 */
1755 if (ctlr->fw_translate_cs) {
1756 int cs = ctlr->fw_translate_cs(ctlr,
1757 sb->device_selection);
1758 if (cs < 0)
1759 return cs;
1760 spi->chip_select = cs;
1761 } else {
1762 spi->chip_select = sb->device_selection;
1763 }
1764
1765 spi->max_speed_hz = sb->connection_speed;
1766
1767 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1768 spi->mode |= SPI_CPHA;
1769 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1770 spi->mode |= SPI_CPOL;
1771 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1772 spi->mode |= SPI_CS_HIGH;
1773 }
1774 } else if (spi->irq < 0) {
1775 struct resource r;
1776
1777 if (acpi_dev_resource_interrupt(ares, 0, &r))
1778 spi->irq = r.start;
1779 }
1780
1781 /* Always tell the ACPI core to skip this resource */
1782 return 1;
1783}
1784
1785static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
1786 struct acpi_device *adev)
1787{
1788 struct list_head resource_list;
1789 struct spi_device *spi;
1790 int ret;
1791
1792 if (acpi_bus_get_status(adev) || !adev->status.present ||
1793 acpi_device_enumerated(adev))
1794 return AE_OK;
1795
1796 spi = spi_alloc_device(ctlr);
1797 if (!spi) {
1798 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
1799 dev_name(&adev->dev));
1800 return AE_NO_MEMORY;
1801 }
1802
1803 ACPI_COMPANION_SET(&spi->dev, adev);
1804 spi->irq = -1;
1805
1806 INIT_LIST_HEAD(&resource_list);
1807 ret = acpi_dev_get_resources(adev, &resource_list,
1808 acpi_spi_add_resource, spi);
1809 acpi_dev_free_resource_list(&resource_list);
1810
1811 acpi_spi_parse_apple_properties(spi);
1812
1813 if (ret < 0 || !spi->max_speed_hz) {
1814 spi_dev_put(spi);
1815 return AE_OK;
1816 }
1817
1818 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
1819 sizeof(spi->modalias));
1820
1821 if (spi->irq < 0)
1822 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1823
1824 acpi_device_set_enumerated(adev);
1825
1826 adev->power.flags.ignore_parent = true;
1827 if (spi_add_device(spi)) {
1828 adev->power.flags.ignore_parent = false;
1829 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
1830 dev_name(&adev->dev));
1831 spi_dev_put(spi);
1832 }
1833
1834 return AE_OK;
1835}
1836
1837static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1838 void *data, void **return_value)
1839{
1840 struct spi_controller *ctlr = data;
1841 struct acpi_device *adev;
1842
1843 if (acpi_bus_get_device(handle, &adev))
1844 return AE_OK;
1845
1846 return acpi_register_spi_device(ctlr, adev);
1847}
1848
1849static void acpi_register_spi_devices(struct spi_controller *ctlr)
1850{
1851 acpi_status status;
1852 acpi_handle handle;
1853
1854 handle = ACPI_HANDLE(ctlr->dev.parent);
1855 if (!handle)
1856 return;
1857
1858 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1859 acpi_spi_add_device, NULL, ctlr, NULL);
1860 if (ACPI_FAILURE(status))
1861 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
1862}
1863#else
1864static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
1865#endif /* CONFIG_ACPI */
1866
1867static void spi_controller_release(struct device *dev)
1868{
1869 struct spi_controller *ctlr;
1870
1871 ctlr = container_of(dev, struct spi_controller, dev);
1872 kfree(ctlr);
1873}
1874
1875static struct class spi_master_class = {
1876 .name = "spi_master",
1877 .owner = THIS_MODULE,
1878 .dev_release = spi_controller_release,
1879 .dev_groups = spi_master_groups,
1880};
1881
1882#ifdef CONFIG_SPI_SLAVE
1883/**
1884 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
1885 * controller
1886 * @spi: device used for the current transfer
1887 */
1888int spi_slave_abort(struct spi_device *spi)
1889{
1890 struct spi_controller *ctlr = spi->controller;
1891
1892 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
1893 return ctlr->slave_abort(ctlr);
1894
1895 return -ENOTSUPP;
1896}
1897EXPORT_SYMBOL_GPL(spi_slave_abort);
1898
1899static int match_true(struct device *dev, void *data)
1900{
1901 return 1;
1902}
1903
1904static ssize_t spi_slave_show(struct device *dev,
1905 struct device_attribute *attr, char *buf)
1906{
1907 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
1908 dev);
1909 struct device *child;
1910
1911 child = device_find_child(&ctlr->dev, NULL, match_true);
1912 return sprintf(buf, "%s\n",
1913 child ? to_spi_device(child)->modalias : NULL);
1914}
1915
1916static ssize_t spi_slave_store(struct device *dev,
1917 struct device_attribute *attr, const char *buf,
1918 size_t count)
1919{
1920 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
1921 dev);
1922 struct spi_device *spi;
1923 struct device *child;
1924 char name[32];
1925 int rc;
1926
1927 rc = sscanf(buf, "%31s", name);
1928 if (rc != 1 || !name[0])
1929 return -EINVAL;
1930
1931 child = device_find_child(&ctlr->dev, NULL, match_true);
1932 if (child) {
1933 /* Remove registered slave */
1934 device_unregister(child);
1935 put_device(child);
1936 }
1937
1938 if (strcmp(name, "(null)")) {
1939 /* Register new slave */
1940 spi = spi_alloc_device(ctlr);
1941 if (!spi)
1942 return -ENOMEM;
1943
1944 strlcpy(spi->modalias, name, sizeof(spi->modalias));
1945
1946 rc = spi_add_device(spi);
1947 if (rc) {
1948 spi_dev_put(spi);
1949 return rc;
1950 }
1951 }
1952
1953 return count;
1954}
1955
1956static DEVICE_ATTR(slave, 0644, spi_slave_show, spi_slave_store);
1957
1958static struct attribute *spi_slave_attrs[] = {
1959 &dev_attr_slave.attr,
1960 NULL,
1961};
1962
1963static const struct attribute_group spi_slave_group = {
1964 .attrs = spi_slave_attrs,
1965};
1966
1967static const struct attribute_group *spi_slave_groups[] = {
1968 &spi_controller_statistics_group,
1969 &spi_slave_group,
1970 NULL,
1971};
1972
1973static struct class spi_slave_class = {
1974 .name = "spi_slave",
1975 .owner = THIS_MODULE,
1976 .dev_release = spi_controller_release,
1977 .dev_groups = spi_slave_groups,
1978};
1979#else
1980extern struct class spi_slave_class; /* dummy */
1981#endif
1982
1983/**
1984 * __spi_alloc_controller - allocate an SPI master or slave controller
1985 * @dev: the controller, possibly using the platform_bus
1986 * @size: how much zeroed driver-private data to allocate; the pointer to this
1987 * memory is in the driver_data field of the returned device,
1988 * accessible with spi_controller_get_devdata().
1989 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
1990 * slave (true) controller
1991 * Context: can sleep
1992 *
1993 * This call is used only by SPI controller drivers, which are the
1994 * only ones directly touching chip registers. It's how they allocate
1995 * an spi_controller structure, prior to calling spi_register_controller().
1996 *
1997 * This must be called from context that can sleep.
1998 *
1999 * The caller is responsible for assigning the bus number and initializing the
2000 * controller's methods before calling spi_register_controller(); and (after
2001 * errors adding the device) calling spi_controller_put() to prevent a memory
2002 * leak.
2003 *
2004 * Return: the SPI controller structure on success, else NULL.
2005 */
2006struct spi_controller *__spi_alloc_controller(struct device *dev,
2007 unsigned int size, bool slave)
2008{
2009 struct spi_controller *ctlr;
2010
2011 if (!dev)
2012 return NULL;
2013
2014 ctlr = kzalloc(size + sizeof(*ctlr), GFP_KERNEL);
2015 if (!ctlr)
2016 return NULL;
2017
2018 device_initialize(&ctlr->dev);
2019 ctlr->bus_num = -1;
2020 ctlr->num_chipselect = 1;
2021 ctlr->slave = slave;
2022 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2023 ctlr->dev.class = &spi_slave_class;
2024 else
2025 ctlr->dev.class = &spi_master_class;
2026 ctlr->dev.parent = dev;
2027 pm_suspend_ignore_children(&ctlr->dev, true);
2028 spi_controller_set_devdata(ctlr, &ctlr[1]);
2029
2030 return ctlr;
2031}
2032EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2033
2034#ifdef CONFIG_OF
2035static int of_spi_register_master(struct spi_controller *ctlr)
2036{
2037 int nb, i, *cs;
2038 struct device_node *np = ctlr->dev.of_node;
2039
2040 if (!np)
2041 return 0;
2042
2043 nb = of_gpio_named_count(np, "cs-gpios");
2044 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2045
2046 /* Return error only for an incorrectly formed cs-gpios property */
2047 if (nb == 0 || nb == -ENOENT)
2048 return 0;
2049 else if (nb < 0)
2050 return nb;
2051
2052 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2053 GFP_KERNEL);
2054 ctlr->cs_gpios = cs;
2055
2056 if (!ctlr->cs_gpios)
2057 return -ENOMEM;
2058
2059 for (i = 0; i < ctlr->num_chipselect; i++)
2060 cs[i] = -ENOENT;
2061
2062 for (i = 0; i < nb; i++)
2063 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2064
2065 return 0;
2066}
2067#else
2068static int of_spi_register_master(struct spi_controller *ctlr)
2069{
2070 return 0;
2071}
2072#endif
2073
2074static int spi_controller_check_ops(struct spi_controller *ctlr)
2075{
2076 /*
2077 * The controller may implement only the high-level SPI-memory like
2078 * operations if it does not support regular SPI transfers, and this is
2079 * valid use case.
2080 * If ->mem_ops is NULL, we request that at least one of the
2081 * ->transfer_xxx() method be implemented.
2082 */
2083 if (ctlr->mem_ops) {
2084 if (!ctlr->mem_ops->exec_op)
2085 return -EINVAL;
2086 } else if (!ctlr->transfer && !ctlr->transfer_one &&
2087 !ctlr->transfer_one_message) {
2088 return -EINVAL;
2089 }
2090
2091 return 0;
2092}
2093
2094/**
2095 * spi_register_controller - register SPI master or slave controller
2096 * @ctlr: initialized master, originally from spi_alloc_master() or
2097 * spi_alloc_slave()
2098 * Context: can sleep
2099 *
2100 * SPI controllers connect to their drivers using some non-SPI bus,
2101 * such as the platform bus. The final stage of probe() in that code
2102 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2103 *
2104 * SPI controllers use board specific (often SOC specific) bus numbers,
2105 * and board-specific addressing for SPI devices combines those numbers
2106 * with chip select numbers. Since SPI does not directly support dynamic
2107 * device identification, boards need configuration tables telling which
2108 * chip is at which address.
2109 *
2110 * This must be called from context that can sleep. It returns zero on
2111 * success, else a negative error code (dropping the controller's refcount).
2112 * After a successful return, the caller is responsible for calling
2113 * spi_unregister_controller().
2114 *
2115 * Return: zero on success, else a negative error code.
2116 */
2117int spi_register_controller(struct spi_controller *ctlr)
2118{
2119 struct device *dev = ctlr->dev.parent;
2120 struct boardinfo *bi;
2121 int status = -ENODEV;
2122 int id, first_dynamic;
2123
2124 if (!dev)
2125 return -ENODEV;
2126
2127 /*
2128 * Make sure all necessary hooks are implemented before registering
2129 * the SPI controller.
2130 */
2131 status = spi_controller_check_ops(ctlr);
2132 if (status)
2133 return status;
2134
2135 if (!spi_controller_is_slave(ctlr)) {
2136 status = of_spi_register_master(ctlr);
2137 if (status)
2138 return status;
2139 }
2140
2141 /* even if it's just one always-selected device, there must
2142 * be at least one chipselect
2143 */
2144 if (ctlr->num_chipselect == 0)
2145 return -EINVAL;
2146 /* allocate dynamic bus number using Linux idr */
2147 if ((ctlr->bus_num < 0) && ctlr->dev.of_node) {
2148 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2149 if (id >= 0) {
2150 ctlr->bus_num = id;
2151 mutex_lock(&board_lock);
2152 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2153 ctlr->bus_num + 1, GFP_KERNEL);
2154 mutex_unlock(&board_lock);
2155 if (WARN(id < 0, "couldn't get idr"))
2156 return id == -ENOSPC ? -EBUSY : id;
2157 }
2158 }
2159 if (ctlr->bus_num < 0) {
2160 first_dynamic = of_alias_get_highest_id("spi");
2161 if (first_dynamic < 0)
2162 first_dynamic = 0;
2163 else
2164 first_dynamic++;
2165
2166 mutex_lock(&board_lock);
2167 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2168 0, GFP_KERNEL);
2169 mutex_unlock(&board_lock);
2170 if (WARN(id < 0, "couldn't get idr"))
2171 return id;
2172 ctlr->bus_num = id;
2173 }
2174 INIT_LIST_HEAD(&ctlr->queue);
2175 spin_lock_init(&ctlr->queue_lock);
2176 spin_lock_init(&ctlr->bus_lock_spinlock);
2177 mutex_init(&ctlr->bus_lock_mutex);
2178 mutex_init(&ctlr->io_mutex);
2179 ctlr->bus_lock_flag = 0;
2180 init_completion(&ctlr->xfer_completion);
2181 if (!ctlr->max_dma_len)
2182 ctlr->max_dma_len = INT_MAX;
2183
2184 /* register the device, then userspace will see it.
2185 * registration fails if the bus ID is in use.
2186 */
2187 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2188 status = device_add(&ctlr->dev);
2189 if (status < 0) {
2190 /* free bus id */
2191 mutex_lock(&board_lock);
2192 idr_remove(&spi_master_idr, ctlr->bus_num);
2193 mutex_unlock(&board_lock);
2194 goto done;
2195 }
2196 dev_dbg(dev, "registered %s %s\n",
2197 spi_controller_is_slave(ctlr) ? "slave" : "master",
2198 dev_name(&ctlr->dev));
2199
2200 /*
2201 * If we're using a queued driver, start the queue. Note that we don't
2202 * need the queueing logic if the driver is only supporting high-level
2203 * memory operations.
2204 */
2205 if (ctlr->transfer) {
2206 dev_info(dev, "controller is unqueued, this is deprecated\n");
2207 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2208 status = spi_controller_initialize_queue(ctlr);
2209 if (status) {
2210 device_del(&ctlr->dev);
2211 /* free bus id */
2212 mutex_lock(&board_lock);
2213 idr_remove(&spi_master_idr, ctlr->bus_num);
2214 mutex_unlock(&board_lock);
2215 goto done;
2216 }
2217 }
2218 /* add statistics */
2219 spin_lock_init(&ctlr->statistics.lock);
2220
2221 mutex_lock(&board_lock);
2222 list_add_tail(&ctlr->list, &spi_controller_list);
2223 list_for_each_entry(bi, &board_list, list)
2224 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2225 mutex_unlock(&board_lock);
2226
2227 /* Register devices from the device tree and ACPI */
2228 of_register_spi_devices(ctlr);
2229 acpi_register_spi_devices(ctlr);
2230done:
2231 return status;
2232}
2233EXPORT_SYMBOL_GPL(spi_register_controller);
2234
2235static void devm_spi_unregister(struct device *dev, void *res)
2236{
2237 spi_unregister_controller(*(struct spi_controller **)res);
2238}
2239
2240/**
2241 * devm_spi_register_controller - register managed SPI master or slave
2242 * controller
2243 * @dev: device managing SPI controller
2244 * @ctlr: initialized controller, originally from spi_alloc_master() or
2245 * spi_alloc_slave()
2246 * Context: can sleep
2247 *
2248 * Register a SPI device as with spi_register_controller() which will
2249 * automatically be unregistered and freed.
2250 *
2251 * Return: zero on success, else a negative error code.
2252 */
2253int devm_spi_register_controller(struct device *dev,
2254 struct spi_controller *ctlr)
2255{
2256 struct spi_controller **ptr;
2257 int ret;
2258
2259 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2260 if (!ptr)
2261 return -ENOMEM;
2262
2263 ret = spi_register_controller(ctlr);
2264 if (!ret) {
2265 *ptr = ctlr;
2266 devres_add(dev, ptr);
2267 } else {
2268 devres_free(ptr);
2269 }
2270
2271 return ret;
2272}
2273EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2274
2275static int __unregister(struct device *dev, void *null)
2276{
2277 spi_unregister_device(to_spi_device(dev));
2278 return 0;
2279}
2280
2281/**
2282 * spi_unregister_controller - unregister SPI master or slave controller
2283 * @ctlr: the controller being unregistered
2284 * Context: can sleep
2285 *
2286 * This call is used only by SPI controller drivers, which are the
2287 * only ones directly touching chip registers.
2288 *
2289 * This must be called from context that can sleep.
2290 *
2291 * Note that this function also drops a reference to the controller.
2292 */
2293void spi_unregister_controller(struct spi_controller *ctlr)
2294{
2295 struct spi_controller *found;
2296 int id = ctlr->bus_num;
2297 int dummy;
2298
2299 /* First make sure that this controller was ever added */
2300 mutex_lock(&board_lock);
2301 found = idr_find(&spi_master_idr, id);
2302 mutex_unlock(&board_lock);
2303 if (ctlr->queued) {
2304 if (spi_destroy_queue(ctlr))
2305 dev_err(&ctlr->dev, "queue remove failed\n");
2306 }
2307 mutex_lock(&board_lock);
2308 list_del(&ctlr->list);
2309 mutex_unlock(&board_lock);
2310
2311 dummy = device_for_each_child(&ctlr->dev, NULL, __unregister);
2312 device_unregister(&ctlr->dev);
2313 /* free bus id */
2314 mutex_lock(&board_lock);
2315 if (found == ctlr)
2316 idr_remove(&spi_master_idr, id);
2317 mutex_unlock(&board_lock);
2318}
2319EXPORT_SYMBOL_GPL(spi_unregister_controller);
2320
2321int spi_controller_suspend(struct spi_controller *ctlr)
2322{
2323 int ret;
2324
2325 /* Basically no-ops for non-queued controllers */
2326 if (!ctlr->queued)
2327 return 0;
2328
2329 ret = spi_stop_queue(ctlr);
2330 if (ret)
2331 dev_err(&ctlr->dev, "queue stop failed\n");
2332
2333 return ret;
2334}
2335EXPORT_SYMBOL_GPL(spi_controller_suspend);
2336
2337int spi_controller_resume(struct spi_controller *ctlr)
2338{
2339 int ret;
2340
2341 if (!ctlr->queued)
2342 return 0;
2343
2344 ret = spi_start_queue(ctlr);
2345 if (ret)
2346 dev_err(&ctlr->dev, "queue restart failed\n");
2347
2348 return ret;
2349}
2350EXPORT_SYMBOL_GPL(spi_controller_resume);
2351
2352static int __spi_controller_match(struct device *dev, const void *data)
2353{
2354 struct spi_controller *ctlr;
2355 const u16 *bus_num = data;
2356
2357 ctlr = container_of(dev, struct spi_controller, dev);
2358 return ctlr->bus_num == *bus_num;
2359}
2360
2361/**
2362 * spi_busnum_to_master - look up master associated with bus_num
2363 * @bus_num: the master's bus number
2364 * Context: can sleep
2365 *
2366 * This call may be used with devices that are registered after
2367 * arch init time. It returns a refcounted pointer to the relevant
2368 * spi_controller (which the caller must release), or NULL if there is
2369 * no such master registered.
2370 *
2371 * Return: the SPI master structure on success, else NULL.
2372 */
2373struct spi_controller *spi_busnum_to_master(u16 bus_num)
2374{
2375 struct device *dev;
2376 struct spi_controller *ctlr = NULL;
2377
2378 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2379 __spi_controller_match);
2380 if (dev)
2381 ctlr = container_of(dev, struct spi_controller, dev);
2382 /* reference got in class_find_device */
2383 return ctlr;
2384}
2385EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2386
2387/*-------------------------------------------------------------------------*/
2388
2389/* Core methods for SPI resource management */
2390
2391/**
2392 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2393 * during the processing of a spi_message while using
2394 * spi_transfer_one
2395 * @spi: the spi device for which we allocate memory
2396 * @release: the release code to execute for this resource
2397 * @size: size to alloc and return
2398 * @gfp: GFP allocation flags
2399 *
2400 * Return: the pointer to the allocated data
2401 *
2402 * This may get enhanced in the future to allocate from a memory pool
2403 * of the @spi_device or @spi_controller to avoid repeated allocations.
2404 */
2405void *spi_res_alloc(struct spi_device *spi,
2406 spi_res_release_t release,
2407 size_t size, gfp_t gfp)
2408{
2409 struct spi_res *sres;
2410
2411 sres = kzalloc(sizeof(*sres) + size, gfp);
2412 if (!sres)
2413 return NULL;
2414
2415 INIT_LIST_HEAD(&sres->entry);
2416 sres->release = release;
2417
2418 return sres->data;
2419}
2420EXPORT_SYMBOL_GPL(spi_res_alloc);
2421
2422/**
2423 * spi_res_free - free an spi resource
2424 * @res: pointer to the custom data of a resource
2425 *
2426 */
2427void spi_res_free(void *res)
2428{
2429 struct spi_res *sres = container_of(res, struct spi_res, data);
2430
2431 if (!res)
2432 return;
2433
2434 WARN_ON(!list_empty(&sres->entry));
2435 kfree(sres);
2436}
2437EXPORT_SYMBOL_GPL(spi_res_free);
2438
2439/**
2440 * spi_res_add - add a spi_res to the spi_message
2441 * @message: the spi message
2442 * @res: the spi_resource
2443 */
2444void spi_res_add(struct spi_message *message, void *res)
2445{
2446 struct spi_res *sres = container_of(res, struct spi_res, data);
2447
2448 WARN_ON(!list_empty(&sres->entry));
2449 list_add_tail(&sres->entry, &message->resources);
2450}
2451EXPORT_SYMBOL_GPL(spi_res_add);
2452
2453/**
2454 * spi_res_release - release all spi resources for this message
2455 * @ctlr: the @spi_controller
2456 * @message: the @spi_message
2457 */
2458void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
2459{
2460 struct spi_res *res;
2461
2462 while (!list_empty(&message->resources)) {
2463 res = list_last_entry(&message->resources,
2464 struct spi_res, entry);
2465
2466 if (res->release)
2467 res->release(ctlr, message, res->data);
2468
2469 list_del(&res->entry);
2470
2471 kfree(res);
2472 }
2473}
2474EXPORT_SYMBOL_GPL(spi_res_release);
2475
2476/*-------------------------------------------------------------------------*/
2477
2478/* Core methods for spi_message alterations */
2479
2480static void __spi_replace_transfers_release(struct spi_controller *ctlr,
2481 struct spi_message *msg,
2482 void *res)
2483{
2484 struct spi_replaced_transfers *rxfer = res;
2485 size_t i;
2486
2487 /* call extra callback if requested */
2488 if (rxfer->release)
2489 rxfer->release(ctlr, msg, res);
2490
2491 /* insert replaced transfers back into the message */
2492 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2493
2494 /* remove the formerly inserted entries */
2495 for (i = 0; i < rxfer->inserted; i++)
2496 list_del(&rxfer->inserted_transfers[i].transfer_list);
2497}
2498
2499/**
2500 * spi_replace_transfers - replace transfers with several transfers
2501 * and register change with spi_message.resources
2502 * @msg: the spi_message we work upon
2503 * @xfer_first: the first spi_transfer we want to replace
2504 * @remove: number of transfers to remove
2505 * @insert: the number of transfers we want to insert instead
2506 * @release: extra release code necessary in some circumstances
2507 * @extradatasize: extra data to allocate (with alignment guarantees
2508 * of struct @spi_transfer)
2509 * @gfp: gfp flags
2510 *
2511 * Returns: pointer to @spi_replaced_transfers,
2512 * PTR_ERR(...) in case of errors.
2513 */
2514struct spi_replaced_transfers *spi_replace_transfers(
2515 struct spi_message *msg,
2516 struct spi_transfer *xfer_first,
2517 size_t remove,
2518 size_t insert,
2519 spi_replaced_release_t release,
2520 size_t extradatasize,
2521 gfp_t gfp)
2522{
2523 struct spi_replaced_transfers *rxfer;
2524 struct spi_transfer *xfer;
2525 size_t i;
2526
2527 /* allocate the structure using spi_res */
2528 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2529 insert * sizeof(struct spi_transfer)
2530 + sizeof(struct spi_replaced_transfers)
2531 + extradatasize,
2532 gfp);
2533 if (!rxfer)
2534 return ERR_PTR(-ENOMEM);
2535
2536 /* the release code to invoke before running the generic release */
2537 rxfer->release = release;
2538
2539 /* assign extradata */
2540 if (extradatasize)
2541 rxfer->extradata =
2542 &rxfer->inserted_transfers[insert];
2543
2544 /* init the replaced_transfers list */
2545 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2546
2547 /* assign the list_entry after which we should reinsert
2548 * the @replaced_transfers - it may be spi_message.messages!
2549 */
2550 rxfer->replaced_after = xfer_first->transfer_list.prev;
2551
2552 /* remove the requested number of transfers */
2553 for (i = 0; i < remove; i++) {
2554 /* if the entry after replaced_after it is msg->transfers
2555 * then we have been requested to remove more transfers
2556 * than are in the list
2557 */
2558 if (rxfer->replaced_after->next == &msg->transfers) {
2559 dev_err(&msg->spi->dev,
2560 "requested to remove more spi_transfers than are available\n");
2561 /* insert replaced transfers back into the message */
2562 list_splice(&rxfer->replaced_transfers,
2563 rxfer->replaced_after);
2564
2565 /* free the spi_replace_transfer structure */
2566 spi_res_free(rxfer);
2567
2568 /* and return with an error */
2569 return ERR_PTR(-EINVAL);
2570 }
2571
2572 /* remove the entry after replaced_after from list of
2573 * transfers and add it to list of replaced_transfers
2574 */
2575 list_move_tail(rxfer->replaced_after->next,
2576 &rxfer->replaced_transfers);
2577 }
2578
2579 /* create copy of the given xfer with identical settings
2580 * based on the first transfer to get removed
2581 */
2582 for (i = 0; i < insert; i++) {
2583 /* we need to run in reverse order */
2584 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2585
2586 /* copy all spi_transfer data */
2587 memcpy(xfer, xfer_first, sizeof(*xfer));
2588
2589 /* add to list */
2590 list_add(&xfer->transfer_list, rxfer->replaced_after);
2591
2592 /* clear cs_change and delay_usecs for all but the last */
2593 if (i) {
2594 xfer->cs_change = false;
2595 xfer->delay_usecs = 0;
2596 }
2597 }
2598
2599 /* set up inserted */
2600 rxfer->inserted = insert;
2601
2602 /* and register it with spi_res/spi_message */
2603 spi_res_add(msg, rxfer);
2604
2605 return rxfer;
2606}
2607EXPORT_SYMBOL_GPL(spi_replace_transfers);
2608
2609static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
2610 struct spi_message *msg,
2611 struct spi_transfer **xferp,
2612 size_t maxsize,
2613 gfp_t gfp)
2614{
2615 struct spi_transfer *xfer = *xferp, *xfers;
2616 struct spi_replaced_transfers *srt;
2617 size_t offset;
2618 size_t count, i;
2619
2620 /* warn once about this fact that we are splitting a transfer */
2621 dev_warn_once(&msg->spi->dev,
2622 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2623 xfer->len, maxsize);
2624
2625 /* calculate how many we have to replace */
2626 count = DIV_ROUND_UP(xfer->len, maxsize);
2627
2628 /* create replacement */
2629 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
2630 if (IS_ERR(srt))
2631 return PTR_ERR(srt);
2632 xfers = srt->inserted_transfers;
2633
2634 /* now handle each of those newly inserted spi_transfers
2635 * note that the replacements spi_transfers all are preset
2636 * to the same values as *xferp, so tx_buf, rx_buf and len
2637 * are all identical (as well as most others)
2638 * so we just have to fix up len and the pointers.
2639 *
2640 * this also includes support for the depreciated
2641 * spi_message.is_dma_mapped interface
2642 */
2643
2644 /* the first transfer just needs the length modified, so we
2645 * run it outside the loop
2646 */
2647 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
2648
2649 /* all the others need rx_buf/tx_buf also set */
2650 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2651 /* update rx_buf, tx_buf and dma */
2652 if (xfers[i].rx_buf)
2653 xfers[i].rx_buf += offset;
2654 if (xfers[i].rx_dma)
2655 xfers[i].rx_dma += offset;
2656 if (xfers[i].tx_buf)
2657 xfers[i].tx_buf += offset;
2658 if (xfers[i].tx_dma)
2659 xfers[i].tx_dma += offset;
2660
2661 /* update length */
2662 xfers[i].len = min(maxsize, xfers[i].len - offset);
2663 }
2664
2665 /* we set up xferp to the last entry we have inserted,
2666 * so that we skip those already split transfers
2667 */
2668 *xferp = &xfers[count - 1];
2669
2670 /* increment statistics counters */
2671 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
2672 transfers_split_maxsize);
2673 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2674 transfers_split_maxsize);
2675
2676 return 0;
2677}
2678
2679/**
2680 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2681 * when an individual transfer exceeds a
2682 * certain size
2683 * @ctlr: the @spi_controller for this transfer
2684 * @msg: the @spi_message to transform
2685 * @maxsize: the maximum when to apply this
2686 * @gfp: GFP allocation flags
2687 *
2688 * Return: status of transformation
2689 */
2690int spi_split_transfers_maxsize(struct spi_controller *ctlr,
2691 struct spi_message *msg,
2692 size_t maxsize,
2693 gfp_t gfp)
2694{
2695 struct spi_transfer *xfer;
2696 int ret;
2697
2698 /* iterate over the transfer_list,
2699 * but note that xfer is advanced to the last transfer inserted
2700 * to avoid checking sizes again unnecessarily (also xfer does
2701 * potentiall belong to a different list by the time the
2702 * replacement has happened
2703 */
2704 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2705 if (xfer->len > maxsize) {
2706 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
2707 maxsize, gfp);
2708 if (ret)
2709 return ret;
2710 }
2711 }
2712
2713 return 0;
2714}
2715EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2716
2717/*-------------------------------------------------------------------------*/
2718
2719/* Core methods for SPI controller protocol drivers. Some of the
2720 * other core methods are currently defined as inline functions.
2721 */
2722
2723static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
2724 u8 bits_per_word)
2725{
2726 if (ctlr->bits_per_word_mask) {
2727 /* Only 32 bits fit in the mask */
2728 if (bits_per_word > 32)
2729 return -EINVAL;
2730 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
2731 return -EINVAL;
2732 }
2733
2734 return 0;
2735}
2736
2737/**
2738 * spi_setup - setup SPI mode and clock rate
2739 * @spi: the device whose settings are being modified
2740 * Context: can sleep, and no requests are queued to the device
2741 *
2742 * SPI protocol drivers may need to update the transfer mode if the
2743 * device doesn't work with its default. They may likewise need
2744 * to update clock rates or word sizes from initial values. This function
2745 * changes those settings, and must be called from a context that can sleep.
2746 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2747 * effect the next time the device is selected and data is transferred to
2748 * or from it. When this function returns, the spi device is deselected.
2749 *
2750 * Note that this call will fail if the protocol driver specifies an option
2751 * that the underlying controller or its driver does not support. For
2752 * example, not all hardware supports wire transfers using nine bit words,
2753 * LSB-first wire encoding, or active-high chipselects.
2754 *
2755 * Return: zero on success, else a negative error code.
2756 */
2757int spi_setup(struct spi_device *spi)
2758{
2759 unsigned bad_bits, ugly_bits;
2760 int status;
2761
2762 /* check mode to prevent that DUAL and QUAD set at the same time
2763 */
2764 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2765 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2766 dev_err(&spi->dev,
2767 "setup: can not select dual and quad at the same time\n");
2768 return -EINVAL;
2769 }
2770 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2771 */
2772 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2773 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2774 return -EINVAL;
2775 /* help drivers fail *cleanly* when they need options
2776 * that aren't supported with their current controller
2777 * SPI_CS_WORD has a fallback software implementation,
2778 * so it is ignored here.
2779 */
2780 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
2781 ugly_bits = bad_bits &
2782 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2783 if (ugly_bits) {
2784 dev_warn(&spi->dev,
2785 "setup: ignoring unsupported mode bits %x\n",
2786 ugly_bits);
2787 spi->mode &= ~ugly_bits;
2788 bad_bits &= ~ugly_bits;
2789 }
2790 if (bad_bits) {
2791 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
2792 bad_bits);
2793 return -EINVAL;
2794 }
2795
2796 if (!spi->bits_per_word)
2797 spi->bits_per_word = 8;
2798
2799 status = __spi_validate_bits_per_word(spi->controller,
2800 spi->bits_per_word);
2801 if (status)
2802 return status;
2803
2804 if (!spi->max_speed_hz)
2805 spi->max_speed_hz = spi->controller->max_speed_hz;
2806
2807 if (spi->controller->setup)
2808 status = spi->controller->setup(spi);
2809
2810 spi_set_cs(spi, false);
2811
2812 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2813 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2814 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2815 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2816 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2817 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2818 spi->bits_per_word, spi->max_speed_hz,
2819 status);
2820
2821 return status;
2822}
2823EXPORT_SYMBOL_GPL(spi_setup);
2824
2825static int __spi_validate(struct spi_device *spi, struct spi_message *message)
2826{
2827 struct spi_controller *ctlr = spi->controller;
2828 struct spi_transfer *xfer;
2829 int w_size;
2830
2831 if (list_empty(&message->transfers))
2832 return -EINVAL;
2833
2834 /* If an SPI controller does not support toggling the CS line on each
2835 * transfer (indicated by the SPI_CS_WORD flag), we can emulate it by
2836 * splitting transfers into one-word transfers and ensuring that
2837 * cs_change is set for each transfer.
2838 */
2839 if ((spi->mode & SPI_CS_WORD) && !(ctlr->mode_bits & SPI_CS_WORD)) {
2840 size_t maxsize;
2841 int ret;
2842
2843 maxsize = (spi->bits_per_word + 7) / 8;
2844
2845 /* spi_split_transfers_maxsize() requires message->spi */
2846 message->spi = spi;
2847
2848 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
2849 GFP_KERNEL);
2850 if (ret)
2851 return ret;
2852
2853 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2854 /* don't change cs_change on the last entry in the list */
2855 if (list_is_last(&xfer->transfer_list, &message->transfers))
2856 break;
2857 xfer->cs_change = 1;
2858 }
2859 }
2860
2861 /* Half-duplex links include original MicroWire, and ones with
2862 * only one data pin like SPI_3WIRE (switches direction) or where
2863 * either MOSI or MISO is missing. They can also be caused by
2864 * software limitations.
2865 */
2866 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
2867 (spi->mode & SPI_3WIRE)) {
2868 unsigned flags = ctlr->flags;
2869
2870 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2871 if (xfer->rx_buf && xfer->tx_buf)
2872 return -EINVAL;
2873 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
2874 return -EINVAL;
2875 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
2876 return -EINVAL;
2877 }
2878 }
2879
2880 /**
2881 * Set transfer bits_per_word and max speed as spi device default if
2882 * it is not set for this transfer.
2883 * Set transfer tx_nbits and rx_nbits as single transfer default
2884 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2885 */
2886 message->frame_length = 0;
2887 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2888 message->frame_length += xfer->len;
2889 if (!xfer->bits_per_word)
2890 xfer->bits_per_word = spi->bits_per_word;
2891
2892 if (!xfer->speed_hz)
2893 xfer->speed_hz = spi->max_speed_hz;
2894 if (!xfer->speed_hz)
2895 xfer->speed_hz = ctlr->max_speed_hz;
2896
2897 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
2898 xfer->speed_hz = ctlr->max_speed_hz;
2899
2900 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
2901 return -EINVAL;
2902
2903 /*
2904 * SPI transfer length should be multiple of SPI word size
2905 * where SPI word size should be power-of-two multiple
2906 */
2907 if (xfer->bits_per_word <= 8)
2908 w_size = 1;
2909 else if (xfer->bits_per_word <= 16)
2910 w_size = 2;
2911 else
2912 w_size = 4;
2913
2914 /* No partial transfers accepted */
2915 if (xfer->len % w_size)
2916 return -EINVAL;
2917
2918 if (xfer->speed_hz && ctlr->min_speed_hz &&
2919 xfer->speed_hz < ctlr->min_speed_hz)
2920 return -EINVAL;
2921
2922 if (xfer->tx_buf && !xfer->tx_nbits)
2923 xfer->tx_nbits = SPI_NBITS_SINGLE;
2924 if (xfer->rx_buf && !xfer->rx_nbits)
2925 xfer->rx_nbits = SPI_NBITS_SINGLE;
2926 /* check transfer tx/rx_nbits:
2927 * 1. check the value matches one of single, dual and quad
2928 * 2. check tx/rx_nbits match the mode in spi_device
2929 */
2930 if (xfer->tx_buf) {
2931 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2932 xfer->tx_nbits != SPI_NBITS_DUAL &&
2933 xfer->tx_nbits != SPI_NBITS_QUAD)
2934 return -EINVAL;
2935 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2936 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2937 return -EINVAL;
2938 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2939 !(spi->mode & SPI_TX_QUAD))
2940 return -EINVAL;
2941 }
2942 /* check transfer rx_nbits */
2943 if (xfer->rx_buf) {
2944 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2945 xfer->rx_nbits != SPI_NBITS_DUAL &&
2946 xfer->rx_nbits != SPI_NBITS_QUAD)
2947 return -EINVAL;
2948 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2949 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2950 return -EINVAL;
2951 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2952 !(spi->mode & SPI_RX_QUAD))
2953 return -EINVAL;
2954 }
2955 }
2956
2957 message->status = -EINPROGRESS;
2958
2959 return 0;
2960}
2961
2962static int __spi_async(struct spi_device *spi, struct spi_message *message)
2963{
2964 struct spi_controller *ctlr = spi->controller;
2965
2966 /*
2967 * Some controllers do not support doing regular SPI transfers. Return
2968 * ENOTSUPP when this is the case.
2969 */
2970 if (!ctlr->transfer)
2971 return -ENOTSUPP;
2972
2973 message->spi = spi;
2974
2975 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
2976 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2977
2978 trace_spi_message_submit(message);
2979
2980 return ctlr->transfer(spi, message);
2981}
2982
2983/**
2984 * spi_async - asynchronous SPI transfer
2985 * @spi: device with which data will be exchanged
2986 * @message: describes the data transfers, including completion callback
2987 * Context: any (irqs may be blocked, etc)
2988 *
2989 * This call may be used in_irq and other contexts which can't sleep,
2990 * as well as from task contexts which can sleep.
2991 *
2992 * The completion callback is invoked in a context which can't sleep.
2993 * Before that invocation, the value of message->status is undefined.
2994 * When the callback is issued, message->status holds either zero (to
2995 * indicate complete success) or a negative error code. After that
2996 * callback returns, the driver which issued the transfer request may
2997 * deallocate the associated memory; it's no longer in use by any SPI
2998 * core or controller driver code.
2999 *
3000 * Note that although all messages to a spi_device are handled in
3001 * FIFO order, messages may go to different devices in other orders.
3002 * Some device might be higher priority, or have various "hard" access
3003 * time requirements, for example.
3004 *
3005 * On detection of any fault during the transfer, processing of
3006 * the entire message is aborted, and the device is deselected.
3007 * Until returning from the associated message completion callback,
3008 * no other spi_message queued to that device will be processed.
3009 * (This rule applies equally to all the synchronous transfer calls,
3010 * which are wrappers around this core asynchronous primitive.)
3011 *
3012 * Return: zero on success, else a negative error code.
3013 */
3014int spi_async(struct spi_device *spi, struct spi_message *message)
3015{
3016 struct spi_controller *ctlr = spi->controller;
3017 int ret;
3018 unsigned long flags;
3019
3020 ret = __spi_validate(spi, message);
3021 if (ret != 0)
3022 return ret;
3023
3024 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3025
3026 if (ctlr->bus_lock_flag)
3027 ret = -EBUSY;
3028 else
3029 ret = __spi_async(spi, message);
3030
3031 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3032
3033 return ret;
3034}
3035EXPORT_SYMBOL_GPL(spi_async);
3036
3037/**
3038 * spi_async_locked - version of spi_async with exclusive bus usage
3039 * @spi: device with which data will be exchanged
3040 * @message: describes the data transfers, including completion callback
3041 * Context: any (irqs may be blocked, etc)
3042 *
3043 * This call may be used in_irq and other contexts which can't sleep,
3044 * as well as from task contexts which can sleep.
3045 *
3046 * The completion callback is invoked in a context which can't sleep.
3047 * Before that invocation, the value of message->status is undefined.
3048 * When the callback is issued, message->status holds either zero (to
3049 * indicate complete success) or a negative error code. After that
3050 * callback returns, the driver which issued the transfer request may
3051 * deallocate the associated memory; it's no longer in use by any SPI
3052 * core or controller driver code.
3053 *
3054 * Note that although all messages to a spi_device are handled in
3055 * FIFO order, messages may go to different devices in other orders.
3056 * Some device might be higher priority, or have various "hard" access
3057 * time requirements, for example.
3058 *
3059 * On detection of any fault during the transfer, processing of
3060 * the entire message is aborted, and the device is deselected.
3061 * Until returning from the associated message completion callback,
3062 * no other spi_message queued to that device will be processed.
3063 * (This rule applies equally to all the synchronous transfer calls,
3064 * which are wrappers around this core asynchronous primitive.)
3065 *
3066 * Return: zero on success, else a negative error code.
3067 */
3068int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3069{
3070 struct spi_controller *ctlr = spi->controller;
3071 int ret;
3072 unsigned long flags;
3073
3074 ret = __spi_validate(spi, message);
3075 if (ret != 0)
3076 return ret;
3077
3078 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3079
3080 ret = __spi_async(spi, message);
3081
3082 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3083
3084 return ret;
3085
3086}
3087EXPORT_SYMBOL_GPL(spi_async_locked);
3088
3089/*-------------------------------------------------------------------------*/
3090
3091/* Utility methods for SPI protocol drivers, layered on
3092 * top of the core. Some other utility methods are defined as
3093 * inline functions.
3094 */
3095
3096static void spi_complete(void *arg)
3097{
3098 complete(arg);
3099}
3100
3101static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3102{
3103 DECLARE_COMPLETION_ONSTACK(done);
3104 int status;
3105 struct spi_controller *ctlr = spi->controller;
3106 unsigned long flags;
3107
3108 status = __spi_validate(spi, message);
3109 if (status != 0)
3110 return status;
3111
3112 message->complete = spi_complete;
3113 message->context = &done;
3114 message->spi = spi;
3115
3116 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3117 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3118
3119 /* If we're not using the legacy transfer method then we will
3120 * try to transfer in the calling context so special case.
3121 * This code would be less tricky if we could remove the
3122 * support for driver implemented message queues.
3123 */
3124 if (ctlr->transfer == spi_queued_transfer) {
3125 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3126
3127 trace_spi_message_submit(message);
3128
3129 status = __spi_queued_transfer(spi, message, false);
3130
3131 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3132 } else {
3133 status = spi_async_locked(spi, message);
3134 }
3135
3136 if (status == 0) {
3137 /* Push out the messages in the calling context if we
3138 * can.
3139 */
3140 if (ctlr->transfer == spi_queued_transfer) {
3141 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3142 spi_sync_immediate);
3143 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3144 spi_sync_immediate);
3145 __spi_pump_messages(ctlr, false);
3146 }
3147
3148 wait_for_completion(&done);
3149 status = message->status;
3150 }
3151 message->context = NULL;
3152 return status;
3153}
3154
3155/**
3156 * spi_sync - blocking/synchronous SPI data transfers
3157 * @spi: device with which data will be exchanged
3158 * @message: describes the data transfers
3159 * Context: can sleep
3160 *
3161 * This call may only be used from a context that may sleep. The sleep
3162 * is non-interruptible, and has no timeout. Low-overhead controller
3163 * drivers may DMA directly into and out of the message buffers.
3164 *
3165 * Note that the SPI device's chip select is active during the message,
3166 * and then is normally disabled between messages. Drivers for some
3167 * frequently-used devices may want to minimize costs of selecting a chip,
3168 * by leaving it selected in anticipation that the next message will go
3169 * to the same chip. (That may increase power usage.)
3170 *
3171 * Also, the caller is guaranteeing that the memory associated with the
3172 * message will not be freed before this call returns.
3173 *
3174 * Return: zero on success, else a negative error code.
3175 */
3176int spi_sync(struct spi_device *spi, struct spi_message *message)
3177{
3178 int ret;
3179
3180 mutex_lock(&spi->controller->bus_lock_mutex);
3181 ret = __spi_sync(spi, message);
3182 mutex_unlock(&spi->controller->bus_lock_mutex);
3183
3184 return ret;
3185}
3186EXPORT_SYMBOL_GPL(spi_sync);
3187
3188/**
3189 * spi_sync_locked - version of spi_sync with exclusive bus usage
3190 * @spi: device with which data will be exchanged
3191 * @message: describes the data transfers
3192 * Context: can sleep
3193 *
3194 * This call may only be used from a context that may sleep. The sleep
3195 * is non-interruptible, and has no timeout. Low-overhead controller
3196 * drivers may DMA directly into and out of the message buffers.
3197 *
3198 * This call should be used by drivers that require exclusive access to the
3199 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3200 * be released by a spi_bus_unlock call when the exclusive access is over.
3201 *
3202 * Return: zero on success, else a negative error code.
3203 */
3204int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3205{
3206 return __spi_sync(spi, message);
3207}
3208EXPORT_SYMBOL_GPL(spi_sync_locked);
3209
3210/**
3211 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3212 * @ctlr: SPI bus master that should be locked for exclusive bus access
3213 * Context: can sleep
3214 *
3215 * This call may only be used from a context that may sleep. The sleep
3216 * is non-interruptible, and has no timeout.
3217 *
3218 * This call should be used by drivers that require exclusive access to the
3219 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3220 * exclusive access is over. Data transfer must be done by spi_sync_locked
3221 * and spi_async_locked calls when the SPI bus lock is held.
3222 *
3223 * Return: always zero.
3224 */
3225int spi_bus_lock(struct spi_controller *ctlr)
3226{
3227 unsigned long flags;
3228
3229 mutex_lock(&ctlr->bus_lock_mutex);
3230
3231 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3232 ctlr->bus_lock_flag = 1;
3233 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3234
3235 /* mutex remains locked until spi_bus_unlock is called */
3236
3237 return 0;
3238}
3239EXPORT_SYMBOL_GPL(spi_bus_lock);
3240
3241/**
3242 * spi_bus_unlock - release the lock for exclusive SPI bus usage
3243 * @ctlr: SPI bus master that was locked for exclusive bus access
3244 * Context: can sleep
3245 *
3246 * This call may only be used from a context that may sleep. The sleep
3247 * is non-interruptible, and has no timeout.
3248 *
3249 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3250 * call.
3251 *
3252 * Return: always zero.
3253 */
3254int spi_bus_unlock(struct spi_controller *ctlr)
3255{
3256 ctlr->bus_lock_flag = 0;
3257
3258 mutex_unlock(&ctlr->bus_lock_mutex);
3259
3260 return 0;
3261}
3262EXPORT_SYMBOL_GPL(spi_bus_unlock);
3263
3264/* portable code must never pass more than 32 bytes */
3265#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3266
3267static u8 *buf;
3268
3269/**
3270 * spi_write_then_read - SPI synchronous write followed by read
3271 * @spi: device with which data will be exchanged
3272 * @txbuf: data to be written (need not be dma-safe)
3273 * @n_tx: size of txbuf, in bytes
3274 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3275 * @n_rx: size of rxbuf, in bytes
3276 * Context: can sleep
3277 *
3278 * This performs a half duplex MicroWire style transaction with the
3279 * device, sending txbuf and then reading rxbuf. The return value
3280 * is zero for success, else a negative errno status code.
3281 * This call may only be used from a context that may sleep.
3282 *
3283 * Parameters to this routine are always copied using a small buffer;
3284 * portable code should never use this for more than 32 bytes.
3285 * Performance-sensitive or bulk transfer code should instead use
3286 * spi_{async,sync}() calls with dma-safe buffers.
3287 *
3288 * Return: zero on success, else a negative error code.
3289 */
3290int spi_write_then_read(struct spi_device *spi,
3291 const void *txbuf, unsigned n_tx,
3292 void *rxbuf, unsigned n_rx)
3293{
3294 static DEFINE_MUTEX(lock);
3295
3296 int status;
3297 struct spi_message message;
3298 struct spi_transfer x[2];
3299 u8 *local_buf;
3300
3301 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3302 * copying here, (as a pure convenience thing), but we can
3303 * keep heap costs out of the hot path unless someone else is
3304 * using the pre-allocated buffer or the transfer is too large.
3305 */
3306 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
3307 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3308 GFP_KERNEL | GFP_DMA);
3309 if (!local_buf)
3310 return -ENOMEM;
3311 } else {
3312 local_buf = buf;
3313 }
3314
3315 spi_message_init(&message);
3316 memset(x, 0, sizeof(x));
3317 if (n_tx) {
3318 x[0].len = n_tx;
3319 spi_message_add_tail(&x[0], &message);
3320 }
3321 if (n_rx) {
3322 x[1].len = n_rx;
3323 spi_message_add_tail(&x[1], &message);
3324 }
3325
3326 memcpy(local_buf, txbuf, n_tx);
3327 x[0].tx_buf = local_buf;
3328 x[1].rx_buf = local_buf + n_tx;
3329
3330 /* do the i/o */
3331 status = spi_sync(spi, &message);
3332 if (status == 0)
3333 memcpy(rxbuf, x[1].rx_buf, n_rx);
3334
3335 if (x[0].tx_buf == buf)
3336 mutex_unlock(&lock);
3337 else
3338 kfree(local_buf);
3339
3340 return status;
3341}
3342EXPORT_SYMBOL_GPL(spi_write_then_read);
3343
3344/*-------------------------------------------------------------------------*/
3345
3346#if IS_ENABLED(CONFIG_OF_DYNAMIC)
3347static int __spi_of_device_match(struct device *dev, void *data)
3348{
3349 return dev->of_node == data;
3350}
3351
3352/* must call put_device() when done with returned spi_device device */
3353static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3354{
3355 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3356 __spi_of_device_match);
3357 return dev ? to_spi_device(dev) : NULL;
3358}
3359
3360static int __spi_of_controller_match(struct device *dev, const void *data)
3361{
3362 return dev->of_node == data;
3363}
3364
3365/* the spi controllers are not using spi_bus, so we find it with another way */
3366static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
3367{
3368 struct device *dev;
3369
3370 dev = class_find_device(&spi_master_class, NULL, node,
3371 __spi_of_controller_match);
3372 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3373 dev = class_find_device(&spi_slave_class, NULL, node,
3374 __spi_of_controller_match);
3375 if (!dev)
3376 return NULL;
3377
3378 /* reference got in class_find_device */
3379 return container_of(dev, struct spi_controller, dev);
3380}
3381
3382static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3383 void *arg)
3384{
3385 struct of_reconfig_data *rd = arg;
3386 struct spi_controller *ctlr;
3387 struct spi_device *spi;
3388
3389 switch (of_reconfig_get_state_change(action, arg)) {
3390 case OF_RECONFIG_CHANGE_ADD:
3391 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
3392 if (ctlr == NULL)
3393 return NOTIFY_OK; /* not for us */
3394
3395 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3396 put_device(&ctlr->dev);
3397 return NOTIFY_OK;
3398 }
3399
3400 spi = of_register_spi_device(ctlr, rd->dn);
3401 put_device(&ctlr->dev);
3402
3403 if (IS_ERR(spi)) {
3404 pr_err("%s: failed to create for '%pOF'\n",
3405 __func__, rd->dn);
3406 of_node_clear_flag(rd->dn, OF_POPULATED);
3407 return notifier_from_errno(PTR_ERR(spi));
3408 }
3409 break;
3410
3411 case OF_RECONFIG_CHANGE_REMOVE:
3412 /* already depopulated? */
3413 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3414 return NOTIFY_OK;
3415
3416 /* find our device by node */
3417 spi = of_find_spi_device_by_node(rd->dn);
3418 if (spi == NULL)
3419 return NOTIFY_OK; /* no? not meant for us */
3420
3421 /* unregister takes one ref away */
3422 spi_unregister_device(spi);
3423
3424 /* and put the reference of the find */
3425 put_device(&spi->dev);
3426 break;
3427 }
3428
3429 return NOTIFY_OK;
3430}
3431
3432static struct notifier_block spi_of_notifier = {
3433 .notifier_call = of_spi_notify,
3434};
3435#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3436extern struct notifier_block spi_of_notifier;
3437#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3438
3439#if IS_ENABLED(CONFIG_ACPI)
3440static int spi_acpi_controller_match(struct device *dev, const void *data)
3441{
3442 return ACPI_COMPANION(dev->parent) == data;
3443}
3444
3445static int spi_acpi_device_match(struct device *dev, void *data)
3446{
3447 return ACPI_COMPANION(dev) == data;
3448}
3449
3450static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
3451{
3452 struct device *dev;
3453
3454 dev = class_find_device(&spi_master_class, NULL, adev,
3455 spi_acpi_controller_match);
3456 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3457 dev = class_find_device(&spi_slave_class, NULL, adev,
3458 spi_acpi_controller_match);
3459 if (!dev)
3460 return NULL;
3461
3462 return container_of(dev, struct spi_controller, dev);
3463}
3464
3465static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3466{
3467 struct device *dev;
3468
3469 dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3470
3471 return dev ? to_spi_device(dev) : NULL;
3472}
3473
3474static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3475 void *arg)
3476{
3477 struct acpi_device *adev = arg;
3478 struct spi_controller *ctlr;
3479 struct spi_device *spi;
3480
3481 switch (value) {
3482 case ACPI_RECONFIG_DEVICE_ADD:
3483 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
3484 if (!ctlr)
3485 break;
3486
3487 acpi_register_spi_device(ctlr, adev);
3488 put_device(&ctlr->dev);
3489 break;
3490 case ACPI_RECONFIG_DEVICE_REMOVE:
3491 if (!acpi_device_enumerated(adev))
3492 break;
3493
3494 spi = acpi_spi_find_device_by_adev(adev);
3495 if (!spi)
3496 break;
3497
3498 spi_unregister_device(spi);
3499 put_device(&spi->dev);
3500 break;
3501 }
3502
3503 return NOTIFY_OK;
3504}
3505
3506static struct notifier_block spi_acpi_notifier = {
3507 .notifier_call = acpi_spi_notify,
3508};
3509#else
3510extern struct notifier_block spi_acpi_notifier;
3511#endif
3512
3513static int __init spi_init(void)
3514{
3515 int status;
3516
3517 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
3518 if (!buf) {
3519 status = -ENOMEM;
3520 goto err0;
3521 }
3522
3523 status = bus_register(&spi_bus_type);
3524 if (status < 0)
3525 goto err1;
3526
3527 status = class_register(&spi_master_class);
3528 if (status < 0)
3529 goto err2;
3530
3531 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
3532 status = class_register(&spi_slave_class);
3533 if (status < 0)
3534 goto err3;
3535 }
3536
3537 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
3538 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3539 if (IS_ENABLED(CONFIG_ACPI))
3540 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
3541
3542 return 0;
3543
3544err3:
3545 class_unregister(&spi_master_class);
3546err2:
3547 bus_unregister(&spi_bus_type);
3548err1:
3549 kfree(buf);
3550 buf = NULL;
3551err0:
3552 return status;
3553}
3554
3555/* board_info is normally registered in arch_initcall(),
3556 * but even essential drivers wait till later
3557 *
3558 * REVISIT only boardinfo really needs static linking. the rest (device and
3559 * driver registration) _could_ be dynamically linked (modular) ... costs
3560 * include needing to have boardinfo data structures be much more public.
3561 */
3562postcore_initcall(spi_init);
3563
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