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1// SPDX-License-Identifier: GPL-2.0-or-later
2// SPI init/core code
3//
4// Copyright (C) 2005 David Brownell
5// Copyright (C) 2008 Secret Lab Technologies Ltd.
6
7#include <linux/kernel.h>
8#include <linux/device.h>
9#include <linux/init.h>
10#include <linux/cache.h>
11#include <linux/dma-mapping.h>
12#include <linux/dmaengine.h>
13#include <linux/mutex.h>
14#include <linux/of_device.h>
15#include <linux/of_irq.h>
16#include <linux/clk/clk-conf.h>
17#include <linux/slab.h>
18#include <linux/mod_devicetable.h>
19#include <linux/spi/spi.h>
20#include <linux/spi/spi-mem.h>
21#include <linux/gpio/consumer.h>
22#include <linux/pm_runtime.h>
23#include <linux/pm_domain.h>
24#include <linux/property.h>
25#include <linux/export.h>
26#include <linux/sched/rt.h>
27#include <uapi/linux/sched/types.h>
28#include <linux/delay.h>
29#include <linux/kthread.h>
30#include <linux/ioport.h>
31#include <linux/acpi.h>
32#include <linux/highmem.h>
33#include <linux/idr.h>
34#include <linux/platform_data/x86/apple.h>
35#include <linux/ptp_clock_kernel.h>
36#include <linux/percpu.h>
37
38#define CREATE_TRACE_POINTS
39#include <trace/events/spi.h>
40EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start);
41EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop);
42
43#include "internals.h"
44
45static DEFINE_IDR(spi_master_idr);
46
47static void spidev_release(struct device *dev)
48{
49 struct spi_device *spi = to_spi_device(dev);
50
51 spi_controller_put(spi->controller);
52 kfree(spi->driver_override);
53 free_percpu(spi->pcpu_statistics);
54 kfree(spi);
55}
56
57static ssize_t
58modalias_show(struct device *dev, struct device_attribute *a, char *buf)
59{
60 const struct spi_device *spi = to_spi_device(dev);
61 int len;
62
63 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
64 if (len != -ENODEV)
65 return len;
66
67 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
68}
69static DEVICE_ATTR_RO(modalias);
70
71static ssize_t driver_override_store(struct device *dev,
72 struct device_attribute *a,
73 const char *buf, size_t count)
74{
75 struct spi_device *spi = to_spi_device(dev);
76 int ret;
77
78 ret = driver_set_override(dev, &spi->driver_override, buf, count);
79 if (ret)
80 return ret;
81
82 return count;
83}
84
85static ssize_t driver_override_show(struct device *dev,
86 struct device_attribute *a, char *buf)
87{
88 const struct spi_device *spi = to_spi_device(dev);
89 ssize_t len;
90
91 device_lock(dev);
92 len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
93 device_unlock(dev);
94 return len;
95}
96static DEVICE_ATTR_RW(driver_override);
97
98static struct spi_statistics __percpu *spi_alloc_pcpu_stats(struct device *dev)
99{
100 struct spi_statistics __percpu *pcpu_stats;
101
102 if (dev)
103 pcpu_stats = devm_alloc_percpu(dev, struct spi_statistics);
104 else
105 pcpu_stats = alloc_percpu_gfp(struct spi_statistics, GFP_KERNEL);
106
107 if (pcpu_stats) {
108 int cpu;
109
110 for_each_possible_cpu(cpu) {
111 struct spi_statistics *stat;
112
113 stat = per_cpu_ptr(pcpu_stats, cpu);
114 u64_stats_init(&stat->syncp);
115 }
116 }
117 return pcpu_stats;
118}
119
120#define spi_pcpu_stats_totalize(ret, in, field) \
121do { \
122 int i; \
123 ret = 0; \
124 for_each_possible_cpu(i) { \
125 const struct spi_statistics *pcpu_stats; \
126 u64 inc; \
127 unsigned int start; \
128 pcpu_stats = per_cpu_ptr(in, i); \
129 do { \
130 start = u64_stats_fetch_begin( \
131 &pcpu_stats->syncp); \
132 inc = u64_stats_read(&pcpu_stats->field); \
133 } while (u64_stats_fetch_retry( \
134 &pcpu_stats->syncp, start)); \
135 ret += inc; \
136 } \
137} while (0)
138
139#define SPI_STATISTICS_ATTRS(field, file) \
140static ssize_t spi_controller_##field##_show(struct device *dev, \
141 struct device_attribute *attr, \
142 char *buf) \
143{ \
144 struct spi_controller *ctlr = container_of(dev, \
145 struct spi_controller, dev); \
146 return spi_statistics_##field##_show(ctlr->pcpu_statistics, buf); \
147} \
148static struct device_attribute dev_attr_spi_controller_##field = { \
149 .attr = { .name = file, .mode = 0444 }, \
150 .show = spi_controller_##field##_show, \
151}; \
152static ssize_t spi_device_##field##_show(struct device *dev, \
153 struct device_attribute *attr, \
154 char *buf) \
155{ \
156 struct spi_device *spi = to_spi_device(dev); \
157 return spi_statistics_##field##_show(spi->pcpu_statistics, buf); \
158} \
159static struct device_attribute dev_attr_spi_device_##field = { \
160 .attr = { .name = file, .mode = 0444 }, \
161 .show = spi_device_##field##_show, \
162}
163
164#define SPI_STATISTICS_SHOW_NAME(name, file, field) \
165static ssize_t spi_statistics_##name##_show(struct spi_statistics __percpu *stat, \
166 char *buf) \
167{ \
168 ssize_t len; \
169 u64 val; \
170 spi_pcpu_stats_totalize(val, stat, field); \
171 len = sysfs_emit(buf, "%llu\n", val); \
172 return len; \
173} \
174SPI_STATISTICS_ATTRS(name, file)
175
176#define SPI_STATISTICS_SHOW(field) \
177 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
178 field)
179
180SPI_STATISTICS_SHOW(messages);
181SPI_STATISTICS_SHOW(transfers);
182SPI_STATISTICS_SHOW(errors);
183SPI_STATISTICS_SHOW(timedout);
184
185SPI_STATISTICS_SHOW(spi_sync);
186SPI_STATISTICS_SHOW(spi_sync_immediate);
187SPI_STATISTICS_SHOW(spi_async);
188
189SPI_STATISTICS_SHOW(bytes);
190SPI_STATISTICS_SHOW(bytes_rx);
191SPI_STATISTICS_SHOW(bytes_tx);
192
193#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
194 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
195 "transfer_bytes_histo_" number, \
196 transfer_bytes_histo[index])
197SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
198SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
199SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
200SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
201SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
202SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
203SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
204SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
205SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
206SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
207SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
208SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
209SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
210SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
211SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
212SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
213SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
214
215SPI_STATISTICS_SHOW(transfers_split_maxsize);
216
217static struct attribute *spi_dev_attrs[] = {
218 &dev_attr_modalias.attr,
219 &dev_attr_driver_override.attr,
220 NULL,
221};
222
223static const struct attribute_group spi_dev_group = {
224 .attrs = spi_dev_attrs,
225};
226
227static struct attribute *spi_device_statistics_attrs[] = {
228 &dev_attr_spi_device_messages.attr,
229 &dev_attr_spi_device_transfers.attr,
230 &dev_attr_spi_device_errors.attr,
231 &dev_attr_spi_device_timedout.attr,
232 &dev_attr_spi_device_spi_sync.attr,
233 &dev_attr_spi_device_spi_sync_immediate.attr,
234 &dev_attr_spi_device_spi_async.attr,
235 &dev_attr_spi_device_bytes.attr,
236 &dev_attr_spi_device_bytes_rx.attr,
237 &dev_attr_spi_device_bytes_tx.attr,
238 &dev_attr_spi_device_transfer_bytes_histo0.attr,
239 &dev_attr_spi_device_transfer_bytes_histo1.attr,
240 &dev_attr_spi_device_transfer_bytes_histo2.attr,
241 &dev_attr_spi_device_transfer_bytes_histo3.attr,
242 &dev_attr_spi_device_transfer_bytes_histo4.attr,
243 &dev_attr_spi_device_transfer_bytes_histo5.attr,
244 &dev_attr_spi_device_transfer_bytes_histo6.attr,
245 &dev_attr_spi_device_transfer_bytes_histo7.attr,
246 &dev_attr_spi_device_transfer_bytes_histo8.attr,
247 &dev_attr_spi_device_transfer_bytes_histo9.attr,
248 &dev_attr_spi_device_transfer_bytes_histo10.attr,
249 &dev_attr_spi_device_transfer_bytes_histo11.attr,
250 &dev_attr_spi_device_transfer_bytes_histo12.attr,
251 &dev_attr_spi_device_transfer_bytes_histo13.attr,
252 &dev_attr_spi_device_transfer_bytes_histo14.attr,
253 &dev_attr_spi_device_transfer_bytes_histo15.attr,
254 &dev_attr_spi_device_transfer_bytes_histo16.attr,
255 &dev_attr_spi_device_transfers_split_maxsize.attr,
256 NULL,
257};
258
259static const struct attribute_group spi_device_statistics_group = {
260 .name = "statistics",
261 .attrs = spi_device_statistics_attrs,
262};
263
264static const struct attribute_group *spi_dev_groups[] = {
265 &spi_dev_group,
266 &spi_device_statistics_group,
267 NULL,
268};
269
270static struct attribute *spi_controller_statistics_attrs[] = {
271 &dev_attr_spi_controller_messages.attr,
272 &dev_attr_spi_controller_transfers.attr,
273 &dev_attr_spi_controller_errors.attr,
274 &dev_attr_spi_controller_timedout.attr,
275 &dev_attr_spi_controller_spi_sync.attr,
276 &dev_attr_spi_controller_spi_sync_immediate.attr,
277 &dev_attr_spi_controller_spi_async.attr,
278 &dev_attr_spi_controller_bytes.attr,
279 &dev_attr_spi_controller_bytes_rx.attr,
280 &dev_attr_spi_controller_bytes_tx.attr,
281 &dev_attr_spi_controller_transfer_bytes_histo0.attr,
282 &dev_attr_spi_controller_transfer_bytes_histo1.attr,
283 &dev_attr_spi_controller_transfer_bytes_histo2.attr,
284 &dev_attr_spi_controller_transfer_bytes_histo3.attr,
285 &dev_attr_spi_controller_transfer_bytes_histo4.attr,
286 &dev_attr_spi_controller_transfer_bytes_histo5.attr,
287 &dev_attr_spi_controller_transfer_bytes_histo6.attr,
288 &dev_attr_spi_controller_transfer_bytes_histo7.attr,
289 &dev_attr_spi_controller_transfer_bytes_histo8.attr,
290 &dev_attr_spi_controller_transfer_bytes_histo9.attr,
291 &dev_attr_spi_controller_transfer_bytes_histo10.attr,
292 &dev_attr_spi_controller_transfer_bytes_histo11.attr,
293 &dev_attr_spi_controller_transfer_bytes_histo12.attr,
294 &dev_attr_spi_controller_transfer_bytes_histo13.attr,
295 &dev_attr_spi_controller_transfer_bytes_histo14.attr,
296 &dev_attr_spi_controller_transfer_bytes_histo15.attr,
297 &dev_attr_spi_controller_transfer_bytes_histo16.attr,
298 &dev_attr_spi_controller_transfers_split_maxsize.attr,
299 NULL,
300};
301
302static const struct attribute_group spi_controller_statistics_group = {
303 .name = "statistics",
304 .attrs = spi_controller_statistics_attrs,
305};
306
307static const struct attribute_group *spi_master_groups[] = {
308 &spi_controller_statistics_group,
309 NULL,
310};
311
312static void spi_statistics_add_transfer_stats(struct spi_statistics __percpu *pcpu_stats,
313 struct spi_transfer *xfer,
314 struct spi_controller *ctlr)
315{
316 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
317 struct spi_statistics *stats;
318
319 if (l2len < 0)
320 l2len = 0;
321
322 get_cpu();
323 stats = this_cpu_ptr(pcpu_stats);
324 u64_stats_update_begin(&stats->syncp);
325
326 u64_stats_inc(&stats->transfers);
327 u64_stats_inc(&stats->transfer_bytes_histo[l2len]);
328
329 u64_stats_add(&stats->bytes, xfer->len);
330 if ((xfer->tx_buf) &&
331 (xfer->tx_buf != ctlr->dummy_tx))
332 u64_stats_add(&stats->bytes_tx, xfer->len);
333 if ((xfer->rx_buf) &&
334 (xfer->rx_buf != ctlr->dummy_rx))
335 u64_stats_add(&stats->bytes_rx, xfer->len);
336
337 u64_stats_update_end(&stats->syncp);
338 put_cpu();
339}
340
341/*
342 * modalias support makes "modprobe $MODALIAS" new-style hotplug work,
343 * and the sysfs version makes coldplug work too.
344 */
345static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, const char *name)
346{
347 while (id->name[0]) {
348 if (!strcmp(name, id->name))
349 return id;
350 id++;
351 }
352 return NULL;
353}
354
355const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
356{
357 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
358
359 return spi_match_id(sdrv->id_table, sdev->modalias);
360}
361EXPORT_SYMBOL_GPL(spi_get_device_id);
362
363const void *spi_get_device_match_data(const struct spi_device *sdev)
364{
365 const void *match;
366
367 match = device_get_match_data(&sdev->dev);
368 if (match)
369 return match;
370
371 return (const void *)spi_get_device_id(sdev)->driver_data;
372}
373EXPORT_SYMBOL_GPL(spi_get_device_match_data);
374
375static int spi_match_device(struct device *dev, struct device_driver *drv)
376{
377 const struct spi_device *spi = to_spi_device(dev);
378 const struct spi_driver *sdrv = to_spi_driver(drv);
379
380 /* Check override first, and if set, only use the named driver */
381 if (spi->driver_override)
382 return strcmp(spi->driver_override, drv->name) == 0;
383
384 /* Attempt an OF style match */
385 if (of_driver_match_device(dev, drv))
386 return 1;
387
388 /* Then try ACPI */
389 if (acpi_driver_match_device(dev, drv))
390 return 1;
391
392 if (sdrv->id_table)
393 return !!spi_match_id(sdrv->id_table, spi->modalias);
394
395 return strcmp(spi->modalias, drv->name) == 0;
396}
397
398static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
399{
400 const struct spi_device *spi = to_spi_device(dev);
401 int rc;
402
403 rc = acpi_device_uevent_modalias(dev, env);
404 if (rc != -ENODEV)
405 return rc;
406
407 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
408}
409
410static int spi_probe(struct device *dev)
411{
412 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
413 struct spi_device *spi = to_spi_device(dev);
414 int ret;
415
416 ret = of_clk_set_defaults(dev->of_node, false);
417 if (ret)
418 return ret;
419
420 if (dev->of_node) {
421 spi->irq = of_irq_get(dev->of_node, 0);
422 if (spi->irq == -EPROBE_DEFER)
423 return -EPROBE_DEFER;
424 if (spi->irq < 0)
425 spi->irq = 0;
426 }
427
428 ret = dev_pm_domain_attach(dev, true);
429 if (ret)
430 return ret;
431
432 if (sdrv->probe) {
433 ret = sdrv->probe(spi);
434 if (ret)
435 dev_pm_domain_detach(dev, true);
436 }
437
438 return ret;
439}
440
441static void spi_remove(struct device *dev)
442{
443 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
444
445 if (sdrv->remove)
446 sdrv->remove(to_spi_device(dev));
447
448 dev_pm_domain_detach(dev, true);
449}
450
451static void spi_shutdown(struct device *dev)
452{
453 if (dev->driver) {
454 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
455
456 if (sdrv->shutdown)
457 sdrv->shutdown(to_spi_device(dev));
458 }
459}
460
461struct bus_type spi_bus_type = {
462 .name = "spi",
463 .dev_groups = spi_dev_groups,
464 .match = spi_match_device,
465 .uevent = spi_uevent,
466 .probe = spi_probe,
467 .remove = spi_remove,
468 .shutdown = spi_shutdown,
469};
470EXPORT_SYMBOL_GPL(spi_bus_type);
471
472/**
473 * __spi_register_driver - register a SPI driver
474 * @owner: owner module of the driver to register
475 * @sdrv: the driver to register
476 * Context: can sleep
477 *
478 * Return: zero on success, else a negative error code.
479 */
480int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
481{
482 sdrv->driver.owner = owner;
483 sdrv->driver.bus = &spi_bus_type;
484
485 /*
486 * For Really Good Reasons we use spi: modaliases not of:
487 * modaliases for DT so module autoloading won't work if we
488 * don't have a spi_device_id as well as a compatible string.
489 */
490 if (sdrv->driver.of_match_table) {
491 const struct of_device_id *of_id;
492
493 for (of_id = sdrv->driver.of_match_table; of_id->compatible[0];
494 of_id++) {
495 const char *of_name;
496
497 /* Strip off any vendor prefix */
498 of_name = strnchr(of_id->compatible,
499 sizeof(of_id->compatible), ',');
500 if (of_name)
501 of_name++;
502 else
503 of_name = of_id->compatible;
504
505 if (sdrv->id_table) {
506 const struct spi_device_id *spi_id;
507
508 spi_id = spi_match_id(sdrv->id_table, of_name);
509 if (spi_id)
510 continue;
511 } else {
512 if (strcmp(sdrv->driver.name, of_name) == 0)
513 continue;
514 }
515
516 pr_warn("SPI driver %s has no spi_device_id for %s\n",
517 sdrv->driver.name, of_id->compatible);
518 }
519 }
520
521 return driver_register(&sdrv->driver);
522}
523EXPORT_SYMBOL_GPL(__spi_register_driver);
524
525/*-------------------------------------------------------------------------*/
526
527/*
528 * SPI devices should normally not be created by SPI device drivers; that
529 * would make them board-specific. Similarly with SPI controller drivers.
530 * Device registration normally goes into like arch/.../mach.../board-YYY.c
531 * with other readonly (flashable) information about mainboard devices.
532 */
533
534struct boardinfo {
535 struct list_head list;
536 struct spi_board_info board_info;
537};
538
539static LIST_HEAD(board_list);
540static LIST_HEAD(spi_controller_list);
541
542/*
543 * Used to protect add/del operation for board_info list and
544 * spi_controller list, and their matching process also used
545 * to protect object of type struct idr.
546 */
547static DEFINE_MUTEX(board_lock);
548
549/**
550 * spi_alloc_device - Allocate a new SPI device
551 * @ctlr: Controller to which device is connected
552 * Context: can sleep
553 *
554 * Allows a driver to allocate and initialize a spi_device without
555 * registering it immediately. This allows a driver to directly
556 * fill the spi_device with device parameters before calling
557 * spi_add_device() on it.
558 *
559 * Caller is responsible to call spi_add_device() on the returned
560 * spi_device structure to add it to the SPI controller. If the caller
561 * needs to discard the spi_device without adding it, then it should
562 * call spi_dev_put() on it.
563 *
564 * Return: a pointer to the new device, or NULL.
565 */
566struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
567{
568 struct spi_device *spi;
569
570 if (!spi_controller_get(ctlr))
571 return NULL;
572
573 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
574 if (!spi) {
575 spi_controller_put(ctlr);
576 return NULL;
577 }
578
579 spi->pcpu_statistics = spi_alloc_pcpu_stats(NULL);
580 if (!spi->pcpu_statistics) {
581 kfree(spi);
582 spi_controller_put(ctlr);
583 return NULL;
584 }
585
586 spi->master = spi->controller = ctlr;
587 spi->dev.parent = &ctlr->dev;
588 spi->dev.bus = &spi_bus_type;
589 spi->dev.release = spidev_release;
590 spi->mode = ctlr->buswidth_override_bits;
591
592 device_initialize(&spi->dev);
593 return spi;
594}
595EXPORT_SYMBOL_GPL(spi_alloc_device);
596
597static void spi_dev_set_name(struct spi_device *spi)
598{
599 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
600
601 if (adev) {
602 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
603 return;
604 }
605
606 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
607 spi->chip_select);
608}
609
610static int spi_dev_check(struct device *dev, void *data)
611{
612 struct spi_device *spi = to_spi_device(dev);
613 struct spi_device *new_spi = data;
614
615 if (spi->controller == new_spi->controller &&
616 spi->chip_select == new_spi->chip_select)
617 return -EBUSY;
618 return 0;
619}
620
621static void spi_cleanup(struct spi_device *spi)
622{
623 if (spi->controller->cleanup)
624 spi->controller->cleanup(spi);
625}
626
627static int __spi_add_device(struct spi_device *spi)
628{
629 struct spi_controller *ctlr = spi->controller;
630 struct device *dev = ctlr->dev.parent;
631 int status;
632
633 /*
634 * We need to make sure there's no other device with this
635 * chipselect **BEFORE** we call setup(), else we'll trash
636 * its configuration.
637 */
638 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
639 if (status) {
640 dev_err(dev, "chipselect %d already in use\n",
641 spi->chip_select);
642 return status;
643 }
644
645 /* Controller may unregister concurrently */
646 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
647 !device_is_registered(&ctlr->dev)) {
648 return -ENODEV;
649 }
650
651 if (ctlr->cs_gpiods)
652 spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
653
654 /*
655 * Drivers may modify this initial i/o setup, but will
656 * normally rely on the device being setup. Devices
657 * using SPI_CS_HIGH can't coexist well otherwise...
658 */
659 status = spi_setup(spi);
660 if (status < 0) {
661 dev_err(dev, "can't setup %s, status %d\n",
662 dev_name(&spi->dev), status);
663 return status;
664 }
665
666 /* Device may be bound to an active driver when this returns */
667 status = device_add(&spi->dev);
668 if (status < 0) {
669 dev_err(dev, "can't add %s, status %d\n",
670 dev_name(&spi->dev), status);
671 spi_cleanup(spi);
672 } else {
673 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
674 }
675
676 return status;
677}
678
679/**
680 * spi_add_device - Add spi_device allocated with spi_alloc_device
681 * @spi: spi_device to register
682 *
683 * Companion function to spi_alloc_device. Devices allocated with
684 * spi_alloc_device can be added onto the spi bus with this function.
685 *
686 * Return: 0 on success; negative errno on failure
687 */
688int spi_add_device(struct spi_device *spi)
689{
690 struct spi_controller *ctlr = spi->controller;
691 struct device *dev = ctlr->dev.parent;
692 int status;
693
694 /* Chipselects are numbered 0..max; validate. */
695 if (spi->chip_select >= ctlr->num_chipselect) {
696 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
697 ctlr->num_chipselect);
698 return -EINVAL;
699 }
700
701 /* Set the bus ID string */
702 spi_dev_set_name(spi);
703
704 mutex_lock(&ctlr->add_lock);
705 status = __spi_add_device(spi);
706 mutex_unlock(&ctlr->add_lock);
707 return status;
708}
709EXPORT_SYMBOL_GPL(spi_add_device);
710
711static int spi_add_device_locked(struct spi_device *spi)
712{
713 struct spi_controller *ctlr = spi->controller;
714 struct device *dev = ctlr->dev.parent;
715
716 /* Chipselects are numbered 0..max; validate. */
717 if (spi->chip_select >= ctlr->num_chipselect) {
718 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
719 ctlr->num_chipselect);
720 return -EINVAL;
721 }
722
723 /* Set the bus ID string */
724 spi_dev_set_name(spi);
725
726 WARN_ON(!mutex_is_locked(&ctlr->add_lock));
727 return __spi_add_device(spi);
728}
729
730/**
731 * spi_new_device - instantiate one new SPI device
732 * @ctlr: Controller to which device is connected
733 * @chip: Describes the SPI device
734 * Context: can sleep
735 *
736 * On typical mainboards, this is purely internal; and it's not needed
737 * after board init creates the hard-wired devices. Some development
738 * platforms may not be able to use spi_register_board_info though, and
739 * this is exported so that for example a USB or parport based adapter
740 * driver could add devices (which it would learn about out-of-band).
741 *
742 * Return: the new device, or NULL.
743 */
744struct spi_device *spi_new_device(struct spi_controller *ctlr,
745 struct spi_board_info *chip)
746{
747 struct spi_device *proxy;
748 int status;
749
750 /*
751 * NOTE: caller did any chip->bus_num checks necessary.
752 *
753 * Also, unless we change the return value convention to use
754 * error-or-pointer (not NULL-or-pointer), troubleshootability
755 * suggests syslogged diagnostics are best here (ugh).
756 */
757
758 proxy = spi_alloc_device(ctlr);
759 if (!proxy)
760 return NULL;
761
762 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
763
764 proxy->chip_select = chip->chip_select;
765 proxy->max_speed_hz = chip->max_speed_hz;
766 proxy->mode = chip->mode;
767 proxy->irq = chip->irq;
768 strscpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
769 proxy->dev.platform_data = (void *) chip->platform_data;
770 proxy->controller_data = chip->controller_data;
771 proxy->controller_state = NULL;
772
773 if (chip->swnode) {
774 status = device_add_software_node(&proxy->dev, chip->swnode);
775 if (status) {
776 dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n",
777 chip->modalias, status);
778 goto err_dev_put;
779 }
780 }
781
782 status = spi_add_device(proxy);
783 if (status < 0)
784 goto err_dev_put;
785
786 return proxy;
787
788err_dev_put:
789 device_remove_software_node(&proxy->dev);
790 spi_dev_put(proxy);
791 return NULL;
792}
793EXPORT_SYMBOL_GPL(spi_new_device);
794
795/**
796 * spi_unregister_device - unregister a single SPI device
797 * @spi: spi_device to unregister
798 *
799 * Start making the passed SPI device vanish. Normally this would be handled
800 * by spi_unregister_controller().
801 */
802void spi_unregister_device(struct spi_device *spi)
803{
804 if (!spi)
805 return;
806
807 if (spi->dev.of_node) {
808 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
809 of_node_put(spi->dev.of_node);
810 }
811 if (ACPI_COMPANION(&spi->dev))
812 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
813 device_remove_software_node(&spi->dev);
814 device_del(&spi->dev);
815 spi_cleanup(spi);
816 put_device(&spi->dev);
817}
818EXPORT_SYMBOL_GPL(spi_unregister_device);
819
820static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
821 struct spi_board_info *bi)
822{
823 struct spi_device *dev;
824
825 if (ctlr->bus_num != bi->bus_num)
826 return;
827
828 dev = spi_new_device(ctlr, bi);
829 if (!dev)
830 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
831 bi->modalias);
832}
833
834/**
835 * spi_register_board_info - register SPI devices for a given board
836 * @info: array of chip descriptors
837 * @n: how many descriptors are provided
838 * Context: can sleep
839 *
840 * Board-specific early init code calls this (probably during arch_initcall)
841 * with segments of the SPI device table. Any device nodes are created later,
842 * after the relevant parent SPI controller (bus_num) is defined. We keep
843 * this table of devices forever, so that reloading a controller driver will
844 * not make Linux forget about these hard-wired devices.
845 *
846 * Other code can also call this, e.g. a particular add-on board might provide
847 * SPI devices through its expansion connector, so code initializing that board
848 * would naturally declare its SPI devices.
849 *
850 * The board info passed can safely be __initdata ... but be careful of
851 * any embedded pointers (platform_data, etc), they're copied as-is.
852 *
853 * Return: zero on success, else a negative error code.
854 */
855int spi_register_board_info(struct spi_board_info const *info, unsigned n)
856{
857 struct boardinfo *bi;
858 int i;
859
860 if (!n)
861 return 0;
862
863 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
864 if (!bi)
865 return -ENOMEM;
866
867 for (i = 0; i < n; i++, bi++, info++) {
868 struct spi_controller *ctlr;
869
870 memcpy(&bi->board_info, info, sizeof(*info));
871
872 mutex_lock(&board_lock);
873 list_add_tail(&bi->list, &board_list);
874 list_for_each_entry(ctlr, &spi_controller_list, list)
875 spi_match_controller_to_boardinfo(ctlr,
876 &bi->board_info);
877 mutex_unlock(&board_lock);
878 }
879
880 return 0;
881}
882
883/*-------------------------------------------------------------------------*/
884
885/* Core methods for SPI resource management */
886
887/**
888 * spi_res_alloc - allocate a spi resource that is life-cycle managed
889 * during the processing of a spi_message while using
890 * spi_transfer_one
891 * @spi: the spi device for which we allocate memory
892 * @release: the release code to execute for this resource
893 * @size: size to alloc and return
894 * @gfp: GFP allocation flags
895 *
896 * Return: the pointer to the allocated data
897 *
898 * This may get enhanced in the future to allocate from a memory pool
899 * of the @spi_device or @spi_controller to avoid repeated allocations.
900 */
901static void *spi_res_alloc(struct spi_device *spi, spi_res_release_t release,
902 size_t size, gfp_t gfp)
903{
904 struct spi_res *sres;
905
906 sres = kzalloc(sizeof(*sres) + size, gfp);
907 if (!sres)
908 return NULL;
909
910 INIT_LIST_HEAD(&sres->entry);
911 sres->release = release;
912
913 return sres->data;
914}
915
916/**
917 * spi_res_free - free an spi resource
918 * @res: pointer to the custom data of a resource
919 */
920static void spi_res_free(void *res)
921{
922 struct spi_res *sres = container_of(res, struct spi_res, data);
923
924 if (!res)
925 return;
926
927 WARN_ON(!list_empty(&sres->entry));
928 kfree(sres);
929}
930
931/**
932 * spi_res_add - add a spi_res to the spi_message
933 * @message: the spi message
934 * @res: the spi_resource
935 */
936static void spi_res_add(struct spi_message *message, void *res)
937{
938 struct spi_res *sres = container_of(res, struct spi_res, data);
939
940 WARN_ON(!list_empty(&sres->entry));
941 list_add_tail(&sres->entry, &message->resources);
942}
943
944/**
945 * spi_res_release - release all spi resources for this message
946 * @ctlr: the @spi_controller
947 * @message: the @spi_message
948 */
949static void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
950{
951 struct spi_res *res, *tmp;
952
953 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
954 if (res->release)
955 res->release(ctlr, message, res->data);
956
957 list_del(&res->entry);
958
959 kfree(res);
960 }
961}
962
963/*-------------------------------------------------------------------------*/
964
965static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
966{
967 bool activate = enable;
968
969 /*
970 * Avoid calling into the driver (or doing delays) if the chip select
971 * isn't actually changing from the last time this was called.
972 */
973 if (!force && ((enable && spi->controller->last_cs == spi->chip_select) ||
974 (!enable && spi->controller->last_cs != spi->chip_select)) &&
975 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
976 return;
977
978 trace_spi_set_cs(spi, activate);
979
980 spi->controller->last_cs = enable ? spi->chip_select : -1;
981 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
982
983 if ((spi->cs_gpiod || !spi->controller->set_cs_timing) && !activate) {
984 spi_delay_exec(&spi->cs_hold, NULL);
985 }
986
987 if (spi->mode & SPI_CS_HIGH)
988 enable = !enable;
989
990 if (spi->cs_gpiod) {
991 if (!(spi->mode & SPI_NO_CS)) {
992 /*
993 * Historically ACPI has no means of the GPIO polarity and
994 * thus the SPISerialBus() resource defines it on the per-chip
995 * basis. In order to avoid a chain of negations, the GPIO
996 * polarity is considered being Active High. Even for the cases
997 * when _DSD() is involved (in the updated versions of ACPI)
998 * the GPIO CS polarity must be defined Active High to avoid
999 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
1000 * into account.
1001 */
1002 if (has_acpi_companion(&spi->dev))
1003 gpiod_set_value_cansleep(spi->cs_gpiod, !enable);
1004 else
1005 /* Polarity handled by GPIO library */
1006 gpiod_set_value_cansleep(spi->cs_gpiod, activate);
1007 }
1008 /* Some SPI masters need both GPIO CS & slave_select */
1009 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
1010 spi->controller->set_cs)
1011 spi->controller->set_cs(spi, !enable);
1012 } else if (spi->controller->set_cs) {
1013 spi->controller->set_cs(spi, !enable);
1014 }
1015
1016 if (spi->cs_gpiod || !spi->controller->set_cs_timing) {
1017 if (activate)
1018 spi_delay_exec(&spi->cs_setup, NULL);
1019 else
1020 spi_delay_exec(&spi->cs_inactive, NULL);
1021 }
1022}
1023
1024#ifdef CONFIG_HAS_DMA
1025static int spi_map_buf_attrs(struct spi_controller *ctlr, struct device *dev,
1026 struct sg_table *sgt, void *buf, size_t len,
1027 enum dma_data_direction dir, unsigned long attrs)
1028{
1029 const bool vmalloced_buf = is_vmalloc_addr(buf);
1030 unsigned int max_seg_size = dma_get_max_seg_size(dev);
1031#ifdef CONFIG_HIGHMEM
1032 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
1033 (unsigned long)buf < (PKMAP_BASE +
1034 (LAST_PKMAP * PAGE_SIZE)));
1035#else
1036 const bool kmap_buf = false;
1037#endif
1038 int desc_len;
1039 int sgs;
1040 struct page *vm_page;
1041 struct scatterlist *sg;
1042 void *sg_buf;
1043 size_t min;
1044 int i, ret;
1045
1046 if (vmalloced_buf || kmap_buf) {
1047 desc_len = min_t(unsigned long, max_seg_size, PAGE_SIZE);
1048 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
1049 } else if (virt_addr_valid(buf)) {
1050 desc_len = min_t(size_t, max_seg_size, ctlr->max_dma_len);
1051 sgs = DIV_ROUND_UP(len, desc_len);
1052 } else {
1053 return -EINVAL;
1054 }
1055
1056 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
1057 if (ret != 0)
1058 return ret;
1059
1060 sg = &sgt->sgl[0];
1061 for (i = 0; i < sgs; i++) {
1062
1063 if (vmalloced_buf || kmap_buf) {
1064 /*
1065 * Next scatterlist entry size is the minimum between
1066 * the desc_len and the remaining buffer length that
1067 * fits in a page.
1068 */
1069 min = min_t(size_t, desc_len,
1070 min_t(size_t, len,
1071 PAGE_SIZE - offset_in_page(buf)));
1072 if (vmalloced_buf)
1073 vm_page = vmalloc_to_page(buf);
1074 else
1075 vm_page = kmap_to_page(buf);
1076 if (!vm_page) {
1077 sg_free_table(sgt);
1078 return -ENOMEM;
1079 }
1080 sg_set_page(sg, vm_page,
1081 min, offset_in_page(buf));
1082 } else {
1083 min = min_t(size_t, len, desc_len);
1084 sg_buf = buf;
1085 sg_set_buf(sg, sg_buf, min);
1086 }
1087
1088 buf += min;
1089 len -= min;
1090 sg = sg_next(sg);
1091 }
1092
1093 ret = dma_map_sgtable(dev, sgt, dir, attrs);
1094 if (ret < 0) {
1095 sg_free_table(sgt);
1096 return ret;
1097 }
1098
1099 return 0;
1100}
1101
1102int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
1103 struct sg_table *sgt, void *buf, size_t len,
1104 enum dma_data_direction dir)
1105{
1106 return spi_map_buf_attrs(ctlr, dev, sgt, buf, len, dir, 0);
1107}
1108
1109static void spi_unmap_buf_attrs(struct spi_controller *ctlr,
1110 struct device *dev, struct sg_table *sgt,
1111 enum dma_data_direction dir,
1112 unsigned long attrs)
1113{
1114 if (sgt->orig_nents) {
1115 dma_unmap_sgtable(dev, sgt, dir, attrs);
1116 sg_free_table(sgt);
1117 sgt->orig_nents = 0;
1118 sgt->nents = 0;
1119 }
1120}
1121
1122void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
1123 struct sg_table *sgt, enum dma_data_direction dir)
1124{
1125 spi_unmap_buf_attrs(ctlr, dev, sgt, dir, 0);
1126}
1127
1128static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1129{
1130 struct device *tx_dev, *rx_dev;
1131 struct spi_transfer *xfer;
1132 int ret;
1133
1134 if (!ctlr->can_dma)
1135 return 0;
1136
1137 if (ctlr->dma_tx)
1138 tx_dev = ctlr->dma_tx->device->dev;
1139 else if (ctlr->dma_map_dev)
1140 tx_dev = ctlr->dma_map_dev;
1141 else
1142 tx_dev = ctlr->dev.parent;
1143
1144 if (ctlr->dma_rx)
1145 rx_dev = ctlr->dma_rx->device->dev;
1146 else if (ctlr->dma_map_dev)
1147 rx_dev = ctlr->dma_map_dev;
1148 else
1149 rx_dev = ctlr->dev.parent;
1150
1151 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1152 /* The sync is done before each transfer. */
1153 unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC;
1154
1155 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1156 continue;
1157
1158 if (xfer->tx_buf != NULL) {
1159 ret = spi_map_buf_attrs(ctlr, tx_dev, &xfer->tx_sg,
1160 (void *)xfer->tx_buf,
1161 xfer->len, DMA_TO_DEVICE,
1162 attrs);
1163 if (ret != 0)
1164 return ret;
1165 }
1166
1167 if (xfer->rx_buf != NULL) {
1168 ret = spi_map_buf_attrs(ctlr, rx_dev, &xfer->rx_sg,
1169 xfer->rx_buf, xfer->len,
1170 DMA_FROM_DEVICE, attrs);
1171 if (ret != 0) {
1172 spi_unmap_buf_attrs(ctlr, tx_dev,
1173 &xfer->tx_sg, DMA_TO_DEVICE,
1174 attrs);
1175
1176 return ret;
1177 }
1178 }
1179 }
1180
1181 ctlr->cur_rx_dma_dev = rx_dev;
1182 ctlr->cur_tx_dma_dev = tx_dev;
1183 ctlr->cur_msg_mapped = true;
1184
1185 return 0;
1186}
1187
1188static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
1189{
1190 struct device *rx_dev = ctlr->cur_rx_dma_dev;
1191 struct device *tx_dev = ctlr->cur_tx_dma_dev;
1192 struct spi_transfer *xfer;
1193
1194 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
1195 return 0;
1196
1197 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1198 /* The sync has already been done after each transfer. */
1199 unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC;
1200
1201 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1202 continue;
1203
1204 spi_unmap_buf_attrs(ctlr, rx_dev, &xfer->rx_sg,
1205 DMA_FROM_DEVICE, attrs);
1206 spi_unmap_buf_attrs(ctlr, tx_dev, &xfer->tx_sg,
1207 DMA_TO_DEVICE, attrs);
1208 }
1209
1210 ctlr->cur_msg_mapped = false;
1211
1212 return 0;
1213}
1214
1215static void spi_dma_sync_for_device(struct spi_controller *ctlr,
1216 struct spi_transfer *xfer)
1217{
1218 struct device *rx_dev = ctlr->cur_rx_dma_dev;
1219 struct device *tx_dev = ctlr->cur_tx_dma_dev;
1220
1221 if (!ctlr->cur_msg_mapped)
1222 return;
1223
1224 if (xfer->tx_sg.orig_nents)
1225 dma_sync_sgtable_for_device(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1226 if (xfer->rx_sg.orig_nents)
1227 dma_sync_sgtable_for_device(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1228}
1229
1230static void spi_dma_sync_for_cpu(struct spi_controller *ctlr,
1231 struct spi_transfer *xfer)
1232{
1233 struct device *rx_dev = ctlr->cur_rx_dma_dev;
1234 struct device *tx_dev = ctlr->cur_tx_dma_dev;
1235
1236 if (!ctlr->cur_msg_mapped)
1237 return;
1238
1239 if (xfer->rx_sg.orig_nents)
1240 dma_sync_sgtable_for_cpu(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1241 if (xfer->tx_sg.orig_nents)
1242 dma_sync_sgtable_for_cpu(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1243}
1244#else /* !CONFIG_HAS_DMA */
1245static inline int __spi_map_msg(struct spi_controller *ctlr,
1246 struct spi_message *msg)
1247{
1248 return 0;
1249}
1250
1251static inline int __spi_unmap_msg(struct spi_controller *ctlr,
1252 struct spi_message *msg)
1253{
1254 return 0;
1255}
1256
1257static void spi_dma_sync_for_device(struct spi_controller *ctrl,
1258 struct spi_transfer *xfer)
1259{
1260}
1261
1262static void spi_dma_sync_for_cpu(struct spi_controller *ctrl,
1263 struct spi_transfer *xfer)
1264{
1265}
1266#endif /* !CONFIG_HAS_DMA */
1267
1268static inline int spi_unmap_msg(struct spi_controller *ctlr,
1269 struct spi_message *msg)
1270{
1271 struct spi_transfer *xfer;
1272
1273 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1274 /*
1275 * Restore the original value of tx_buf or rx_buf if they are
1276 * NULL.
1277 */
1278 if (xfer->tx_buf == ctlr->dummy_tx)
1279 xfer->tx_buf = NULL;
1280 if (xfer->rx_buf == ctlr->dummy_rx)
1281 xfer->rx_buf = NULL;
1282 }
1283
1284 return __spi_unmap_msg(ctlr, msg);
1285}
1286
1287static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1288{
1289 struct spi_transfer *xfer;
1290 void *tmp;
1291 unsigned int max_tx, max_rx;
1292
1293 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1294 && !(msg->spi->mode & SPI_3WIRE)) {
1295 max_tx = 0;
1296 max_rx = 0;
1297
1298 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1299 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1300 !xfer->tx_buf)
1301 max_tx = max(xfer->len, max_tx);
1302 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1303 !xfer->rx_buf)
1304 max_rx = max(xfer->len, max_rx);
1305 }
1306
1307 if (max_tx) {
1308 tmp = krealloc(ctlr->dummy_tx, max_tx,
1309 GFP_KERNEL | GFP_DMA | __GFP_ZERO);
1310 if (!tmp)
1311 return -ENOMEM;
1312 ctlr->dummy_tx = tmp;
1313 }
1314
1315 if (max_rx) {
1316 tmp = krealloc(ctlr->dummy_rx, max_rx,
1317 GFP_KERNEL | GFP_DMA);
1318 if (!tmp)
1319 return -ENOMEM;
1320 ctlr->dummy_rx = tmp;
1321 }
1322
1323 if (max_tx || max_rx) {
1324 list_for_each_entry(xfer, &msg->transfers,
1325 transfer_list) {
1326 if (!xfer->len)
1327 continue;
1328 if (!xfer->tx_buf)
1329 xfer->tx_buf = ctlr->dummy_tx;
1330 if (!xfer->rx_buf)
1331 xfer->rx_buf = ctlr->dummy_rx;
1332 }
1333 }
1334 }
1335
1336 return __spi_map_msg(ctlr, msg);
1337}
1338
1339static int spi_transfer_wait(struct spi_controller *ctlr,
1340 struct spi_message *msg,
1341 struct spi_transfer *xfer)
1342{
1343 struct spi_statistics __percpu *statm = ctlr->pcpu_statistics;
1344 struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics;
1345 u32 speed_hz = xfer->speed_hz;
1346 unsigned long long ms;
1347
1348 if (spi_controller_is_slave(ctlr)) {
1349 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1350 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1351 return -EINTR;
1352 }
1353 } else {
1354 if (!speed_hz)
1355 speed_hz = 100000;
1356
1357 /*
1358 * For each byte we wait for 8 cycles of the SPI clock.
1359 * Since speed is defined in Hz and we want milliseconds,
1360 * use respective multiplier, but before the division,
1361 * otherwise we may get 0 for short transfers.
1362 */
1363 ms = 8LL * MSEC_PER_SEC * xfer->len;
1364 do_div(ms, speed_hz);
1365
1366 /*
1367 * Increase it twice and add 200 ms tolerance, use
1368 * predefined maximum in case of overflow.
1369 */
1370 ms += ms + 200;
1371 if (ms > UINT_MAX)
1372 ms = UINT_MAX;
1373
1374 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1375 msecs_to_jiffies(ms));
1376
1377 if (ms == 0) {
1378 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1379 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1380 dev_err(&msg->spi->dev,
1381 "SPI transfer timed out\n");
1382 return -ETIMEDOUT;
1383 }
1384 }
1385
1386 return 0;
1387}
1388
1389static void _spi_transfer_delay_ns(u32 ns)
1390{
1391 if (!ns)
1392 return;
1393 if (ns <= NSEC_PER_USEC) {
1394 ndelay(ns);
1395 } else {
1396 u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC);
1397
1398 if (us <= 10)
1399 udelay(us);
1400 else
1401 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1402 }
1403}
1404
1405int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1406{
1407 u32 delay = _delay->value;
1408 u32 unit = _delay->unit;
1409 u32 hz;
1410
1411 if (!delay)
1412 return 0;
1413
1414 switch (unit) {
1415 case SPI_DELAY_UNIT_USECS:
1416 delay *= NSEC_PER_USEC;
1417 break;
1418 case SPI_DELAY_UNIT_NSECS:
1419 /* Nothing to do here */
1420 break;
1421 case SPI_DELAY_UNIT_SCK:
1422 /* Clock cycles need to be obtained from spi_transfer */
1423 if (!xfer)
1424 return -EINVAL;
1425 /*
1426 * If there is unknown effective speed, approximate it
1427 * by underestimating with half of the requested hz.
1428 */
1429 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1430 if (!hz)
1431 return -EINVAL;
1432
1433 /* Convert delay to nanoseconds */
1434 delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz);
1435 break;
1436 default:
1437 return -EINVAL;
1438 }
1439
1440 return delay;
1441}
1442EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1443
1444int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1445{
1446 int delay;
1447
1448 might_sleep();
1449
1450 if (!_delay)
1451 return -EINVAL;
1452
1453 delay = spi_delay_to_ns(_delay, xfer);
1454 if (delay < 0)
1455 return delay;
1456
1457 _spi_transfer_delay_ns(delay);
1458
1459 return 0;
1460}
1461EXPORT_SYMBOL_GPL(spi_delay_exec);
1462
1463static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1464 struct spi_transfer *xfer)
1465{
1466 u32 default_delay_ns = 10 * NSEC_PER_USEC;
1467 u32 delay = xfer->cs_change_delay.value;
1468 u32 unit = xfer->cs_change_delay.unit;
1469 int ret;
1470
1471 /* Return early on "fast" mode - for everything but USECS */
1472 if (!delay) {
1473 if (unit == SPI_DELAY_UNIT_USECS)
1474 _spi_transfer_delay_ns(default_delay_ns);
1475 return;
1476 }
1477
1478 ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1479 if (ret) {
1480 dev_err_once(&msg->spi->dev,
1481 "Use of unsupported delay unit %i, using default of %luus\n",
1482 unit, default_delay_ns / NSEC_PER_USEC);
1483 _spi_transfer_delay_ns(default_delay_ns);
1484 }
1485}
1486
1487/*
1488 * spi_transfer_one_message - Default implementation of transfer_one_message()
1489 *
1490 * This is a standard implementation of transfer_one_message() for
1491 * drivers which implement a transfer_one() operation. It provides
1492 * standard handling of delays and chip select management.
1493 */
1494static int spi_transfer_one_message(struct spi_controller *ctlr,
1495 struct spi_message *msg)
1496{
1497 struct spi_transfer *xfer;
1498 bool keep_cs = false;
1499 int ret = 0;
1500 struct spi_statistics __percpu *statm = ctlr->pcpu_statistics;
1501 struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics;
1502
1503 xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list);
1504 spi_set_cs(msg->spi, !xfer->cs_off, false);
1505
1506 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1507 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1508
1509 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1510 trace_spi_transfer_start(msg, xfer);
1511
1512 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1513 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1514
1515 if (!ctlr->ptp_sts_supported) {
1516 xfer->ptp_sts_word_pre = 0;
1517 ptp_read_system_prets(xfer->ptp_sts);
1518 }
1519
1520 if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) {
1521 reinit_completion(&ctlr->xfer_completion);
1522
1523fallback_pio:
1524 spi_dma_sync_for_device(ctlr, xfer);
1525 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1526 if (ret < 0) {
1527 spi_dma_sync_for_cpu(ctlr, xfer);
1528
1529 if (ctlr->cur_msg_mapped &&
1530 (xfer->error & SPI_TRANS_FAIL_NO_START)) {
1531 __spi_unmap_msg(ctlr, msg);
1532 ctlr->fallback = true;
1533 xfer->error &= ~SPI_TRANS_FAIL_NO_START;
1534 goto fallback_pio;
1535 }
1536
1537 SPI_STATISTICS_INCREMENT_FIELD(statm,
1538 errors);
1539 SPI_STATISTICS_INCREMENT_FIELD(stats,
1540 errors);
1541 dev_err(&msg->spi->dev,
1542 "SPI transfer failed: %d\n", ret);
1543 goto out;
1544 }
1545
1546 if (ret > 0) {
1547 ret = spi_transfer_wait(ctlr, msg, xfer);
1548 if (ret < 0)
1549 msg->status = ret;
1550 }
1551
1552 spi_dma_sync_for_cpu(ctlr, xfer);
1553 } else {
1554 if (xfer->len)
1555 dev_err(&msg->spi->dev,
1556 "Bufferless transfer has length %u\n",
1557 xfer->len);
1558 }
1559
1560 if (!ctlr->ptp_sts_supported) {
1561 ptp_read_system_postts(xfer->ptp_sts);
1562 xfer->ptp_sts_word_post = xfer->len;
1563 }
1564
1565 trace_spi_transfer_stop(msg, xfer);
1566
1567 if (msg->status != -EINPROGRESS)
1568 goto out;
1569
1570 spi_transfer_delay_exec(xfer);
1571
1572 if (xfer->cs_change) {
1573 if (list_is_last(&xfer->transfer_list,
1574 &msg->transfers)) {
1575 keep_cs = true;
1576 } else {
1577 if (!xfer->cs_off)
1578 spi_set_cs(msg->spi, false, false);
1579 _spi_transfer_cs_change_delay(msg, xfer);
1580 if (!list_next_entry(xfer, transfer_list)->cs_off)
1581 spi_set_cs(msg->spi, true, false);
1582 }
1583 } else if (!list_is_last(&xfer->transfer_list, &msg->transfers) &&
1584 xfer->cs_off != list_next_entry(xfer, transfer_list)->cs_off) {
1585 spi_set_cs(msg->spi, xfer->cs_off, false);
1586 }
1587
1588 msg->actual_length += xfer->len;
1589 }
1590
1591out:
1592 if (ret != 0 || !keep_cs)
1593 spi_set_cs(msg->spi, false, false);
1594
1595 if (msg->status == -EINPROGRESS)
1596 msg->status = ret;
1597
1598 if (msg->status && ctlr->handle_err)
1599 ctlr->handle_err(ctlr, msg);
1600
1601 spi_finalize_current_message(ctlr);
1602
1603 return ret;
1604}
1605
1606/**
1607 * spi_finalize_current_transfer - report completion of a transfer
1608 * @ctlr: the controller reporting completion
1609 *
1610 * Called by SPI drivers using the core transfer_one_message()
1611 * implementation to notify it that the current interrupt driven
1612 * transfer has finished and the next one may be scheduled.
1613 */
1614void spi_finalize_current_transfer(struct spi_controller *ctlr)
1615{
1616 complete(&ctlr->xfer_completion);
1617}
1618EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1619
1620static void spi_idle_runtime_pm(struct spi_controller *ctlr)
1621{
1622 if (ctlr->auto_runtime_pm) {
1623 pm_runtime_mark_last_busy(ctlr->dev.parent);
1624 pm_runtime_put_autosuspend(ctlr->dev.parent);
1625 }
1626}
1627
1628static int __spi_pump_transfer_message(struct spi_controller *ctlr,
1629 struct spi_message *msg, bool was_busy)
1630{
1631 struct spi_transfer *xfer;
1632 int ret;
1633
1634 if (!was_busy && ctlr->auto_runtime_pm) {
1635 ret = pm_runtime_get_sync(ctlr->dev.parent);
1636 if (ret < 0) {
1637 pm_runtime_put_noidle(ctlr->dev.parent);
1638 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1639 ret);
1640 return ret;
1641 }
1642 }
1643
1644 if (!was_busy)
1645 trace_spi_controller_busy(ctlr);
1646
1647 if (!was_busy && ctlr->prepare_transfer_hardware) {
1648 ret = ctlr->prepare_transfer_hardware(ctlr);
1649 if (ret) {
1650 dev_err(&ctlr->dev,
1651 "failed to prepare transfer hardware: %d\n",
1652 ret);
1653
1654 if (ctlr->auto_runtime_pm)
1655 pm_runtime_put(ctlr->dev.parent);
1656
1657 msg->status = ret;
1658 spi_finalize_current_message(ctlr);
1659
1660 return ret;
1661 }
1662 }
1663
1664 trace_spi_message_start(msg);
1665
1666 ret = spi_split_transfers_maxsize(ctlr, msg,
1667 spi_max_transfer_size(msg->spi),
1668 GFP_KERNEL | GFP_DMA);
1669 if (ret) {
1670 msg->status = ret;
1671 spi_finalize_current_message(ctlr);
1672 return ret;
1673 }
1674
1675 if (ctlr->prepare_message) {
1676 ret = ctlr->prepare_message(ctlr, msg);
1677 if (ret) {
1678 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1679 ret);
1680 msg->status = ret;
1681 spi_finalize_current_message(ctlr);
1682 return ret;
1683 }
1684 msg->prepared = true;
1685 }
1686
1687 ret = spi_map_msg(ctlr, msg);
1688 if (ret) {
1689 msg->status = ret;
1690 spi_finalize_current_message(ctlr);
1691 return ret;
1692 }
1693
1694 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1695 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1696 xfer->ptp_sts_word_pre = 0;
1697 ptp_read_system_prets(xfer->ptp_sts);
1698 }
1699 }
1700
1701 /*
1702 * Drivers implementation of transfer_one_message() must arrange for
1703 * spi_finalize_current_message() to get called. Most drivers will do
1704 * this in the calling context, but some don't. For those cases, a
1705 * completion is used to guarantee that this function does not return
1706 * until spi_finalize_current_message() is done accessing
1707 * ctlr->cur_msg.
1708 * Use of the following two flags enable to opportunistically skip the
1709 * use of the completion since its use involves expensive spin locks.
1710 * In case of a race with the context that calls
1711 * spi_finalize_current_message() the completion will always be used,
1712 * due to strict ordering of these flags using barriers.
1713 */
1714 WRITE_ONCE(ctlr->cur_msg_incomplete, true);
1715 WRITE_ONCE(ctlr->cur_msg_need_completion, false);
1716 reinit_completion(&ctlr->cur_msg_completion);
1717 smp_wmb(); /* Make these available to spi_finalize_current_message() */
1718
1719 ret = ctlr->transfer_one_message(ctlr, msg);
1720 if (ret) {
1721 dev_err(&ctlr->dev,
1722 "failed to transfer one message from queue\n");
1723 return ret;
1724 }
1725
1726 WRITE_ONCE(ctlr->cur_msg_need_completion, true);
1727 smp_mb(); /* See spi_finalize_current_message()... */
1728 if (READ_ONCE(ctlr->cur_msg_incomplete))
1729 wait_for_completion(&ctlr->cur_msg_completion);
1730
1731 return 0;
1732}
1733
1734/**
1735 * __spi_pump_messages - function which processes spi message queue
1736 * @ctlr: controller to process queue for
1737 * @in_kthread: true if we are in the context of the message pump thread
1738 *
1739 * This function checks if there is any spi message in the queue that
1740 * needs processing and if so call out to the driver to initialize hardware
1741 * and transfer each message.
1742 *
1743 * Note that it is called both from the kthread itself and also from
1744 * inside spi_sync(); the queue extraction handling at the top of the
1745 * function should deal with this safely.
1746 */
1747static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1748{
1749 struct spi_message *msg;
1750 bool was_busy = false;
1751 unsigned long flags;
1752 int ret;
1753
1754 /* Take the IO mutex */
1755 mutex_lock(&ctlr->io_mutex);
1756
1757 /* Lock queue */
1758 spin_lock_irqsave(&ctlr->queue_lock, flags);
1759
1760 /* Make sure we are not already running a message */
1761 if (ctlr->cur_msg)
1762 goto out_unlock;
1763
1764 /* Check if the queue is idle */
1765 if (list_empty(&ctlr->queue) || !ctlr->running) {
1766 if (!ctlr->busy)
1767 goto out_unlock;
1768
1769 /* Defer any non-atomic teardown to the thread */
1770 if (!in_kthread) {
1771 if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
1772 !ctlr->unprepare_transfer_hardware) {
1773 spi_idle_runtime_pm(ctlr);
1774 ctlr->busy = false;
1775 ctlr->queue_empty = true;
1776 trace_spi_controller_idle(ctlr);
1777 } else {
1778 kthread_queue_work(ctlr->kworker,
1779 &ctlr->pump_messages);
1780 }
1781 goto out_unlock;
1782 }
1783
1784 ctlr->busy = false;
1785 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1786
1787 kfree(ctlr->dummy_rx);
1788 ctlr->dummy_rx = NULL;
1789 kfree(ctlr->dummy_tx);
1790 ctlr->dummy_tx = NULL;
1791 if (ctlr->unprepare_transfer_hardware &&
1792 ctlr->unprepare_transfer_hardware(ctlr))
1793 dev_err(&ctlr->dev,
1794 "failed to unprepare transfer hardware\n");
1795 spi_idle_runtime_pm(ctlr);
1796 trace_spi_controller_idle(ctlr);
1797
1798 spin_lock_irqsave(&ctlr->queue_lock, flags);
1799 ctlr->queue_empty = true;
1800 goto out_unlock;
1801 }
1802
1803 /* Extract head of queue */
1804 msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1805 ctlr->cur_msg = msg;
1806
1807 list_del_init(&msg->queue);
1808 if (ctlr->busy)
1809 was_busy = true;
1810 else
1811 ctlr->busy = true;
1812 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1813
1814 ret = __spi_pump_transfer_message(ctlr, msg, was_busy);
1815 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1816
1817 ctlr->cur_msg = NULL;
1818 ctlr->fallback = false;
1819
1820 mutex_unlock(&ctlr->io_mutex);
1821
1822 /* Prod the scheduler in case transfer_one() was busy waiting */
1823 if (!ret)
1824 cond_resched();
1825 return;
1826
1827out_unlock:
1828 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1829 mutex_unlock(&ctlr->io_mutex);
1830}
1831
1832/**
1833 * spi_pump_messages - kthread work function which processes spi message queue
1834 * @work: pointer to kthread work struct contained in the controller struct
1835 */
1836static void spi_pump_messages(struct kthread_work *work)
1837{
1838 struct spi_controller *ctlr =
1839 container_of(work, struct spi_controller, pump_messages);
1840
1841 __spi_pump_messages(ctlr, true);
1842}
1843
1844/**
1845 * spi_take_timestamp_pre - helper to collect the beginning of the TX timestamp
1846 * @ctlr: Pointer to the spi_controller structure of the driver
1847 * @xfer: Pointer to the transfer being timestamped
1848 * @progress: How many words (not bytes) have been transferred so far
1849 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1850 * transfer, for less jitter in time measurement. Only compatible
1851 * with PIO drivers. If true, must follow up with
1852 * spi_take_timestamp_post or otherwise system will crash.
1853 * WARNING: for fully predictable results, the CPU frequency must
1854 * also be under control (governor).
1855 *
1856 * This is a helper for drivers to collect the beginning of the TX timestamp
1857 * for the requested byte from the SPI transfer. The frequency with which this
1858 * function must be called (once per word, once for the whole transfer, once
1859 * per batch of words etc) is arbitrary as long as the @tx buffer offset is
1860 * greater than or equal to the requested byte at the time of the call. The
1861 * timestamp is only taken once, at the first such call. It is assumed that
1862 * the driver advances its @tx buffer pointer monotonically.
1863 */
1864void spi_take_timestamp_pre(struct spi_controller *ctlr,
1865 struct spi_transfer *xfer,
1866 size_t progress, bool irqs_off)
1867{
1868 if (!xfer->ptp_sts)
1869 return;
1870
1871 if (xfer->timestamped)
1872 return;
1873
1874 if (progress > xfer->ptp_sts_word_pre)
1875 return;
1876
1877 /* Capture the resolution of the timestamp */
1878 xfer->ptp_sts_word_pre = progress;
1879
1880 if (irqs_off) {
1881 local_irq_save(ctlr->irq_flags);
1882 preempt_disable();
1883 }
1884
1885 ptp_read_system_prets(xfer->ptp_sts);
1886}
1887EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
1888
1889/**
1890 * spi_take_timestamp_post - helper to collect the end of the TX timestamp
1891 * @ctlr: Pointer to the spi_controller structure of the driver
1892 * @xfer: Pointer to the transfer being timestamped
1893 * @progress: How many words (not bytes) have been transferred so far
1894 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1895 *
1896 * This is a helper for drivers to collect the end of the TX timestamp for
1897 * the requested byte from the SPI transfer. Can be called with an arbitrary
1898 * frequency: only the first call where @tx exceeds or is equal to the
1899 * requested word will be timestamped.
1900 */
1901void spi_take_timestamp_post(struct spi_controller *ctlr,
1902 struct spi_transfer *xfer,
1903 size_t progress, bool irqs_off)
1904{
1905 if (!xfer->ptp_sts)
1906 return;
1907
1908 if (xfer->timestamped)
1909 return;
1910
1911 if (progress < xfer->ptp_sts_word_post)
1912 return;
1913
1914 ptp_read_system_postts(xfer->ptp_sts);
1915
1916 if (irqs_off) {
1917 local_irq_restore(ctlr->irq_flags);
1918 preempt_enable();
1919 }
1920
1921 /* Capture the resolution of the timestamp */
1922 xfer->ptp_sts_word_post = progress;
1923
1924 xfer->timestamped = true;
1925}
1926EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
1927
1928/**
1929 * spi_set_thread_rt - set the controller to pump at realtime priority
1930 * @ctlr: controller to boost priority of
1931 *
1932 * This can be called because the controller requested realtime priority
1933 * (by setting the ->rt value before calling spi_register_controller()) or
1934 * because a device on the bus said that its transfers needed realtime
1935 * priority.
1936 *
1937 * NOTE: at the moment if any device on a bus says it needs realtime then
1938 * the thread will be at realtime priority for all transfers on that
1939 * controller. If this eventually becomes a problem we may see if we can
1940 * find a way to boost the priority only temporarily during relevant
1941 * transfers.
1942 */
1943static void spi_set_thread_rt(struct spi_controller *ctlr)
1944{
1945 dev_info(&ctlr->dev,
1946 "will run message pump with realtime priority\n");
1947 sched_set_fifo(ctlr->kworker->task);
1948}
1949
1950static int spi_init_queue(struct spi_controller *ctlr)
1951{
1952 ctlr->running = false;
1953 ctlr->busy = false;
1954 ctlr->queue_empty = true;
1955
1956 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
1957 if (IS_ERR(ctlr->kworker)) {
1958 dev_err(&ctlr->dev, "failed to create message pump kworker\n");
1959 return PTR_ERR(ctlr->kworker);
1960 }
1961
1962 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1963
1964 /*
1965 * Controller config will indicate if this controller should run the
1966 * message pump with high (realtime) priority to reduce the transfer
1967 * latency on the bus by minimising the delay between a transfer
1968 * request and the scheduling of the message pump thread. Without this
1969 * setting the message pump thread will remain at default priority.
1970 */
1971 if (ctlr->rt)
1972 spi_set_thread_rt(ctlr);
1973
1974 return 0;
1975}
1976
1977/**
1978 * spi_get_next_queued_message() - called by driver to check for queued
1979 * messages
1980 * @ctlr: the controller to check for queued messages
1981 *
1982 * If there are more messages in the queue, the next message is returned from
1983 * this call.
1984 *
1985 * Return: the next message in the queue, else NULL if the queue is empty.
1986 */
1987struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1988{
1989 struct spi_message *next;
1990 unsigned long flags;
1991
1992 /* Get a pointer to the next message, if any */
1993 spin_lock_irqsave(&ctlr->queue_lock, flags);
1994 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1995 queue);
1996 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1997
1998 return next;
1999}
2000EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
2001
2002/**
2003 * spi_finalize_current_message() - the current message is complete
2004 * @ctlr: the controller to return the message to
2005 *
2006 * Called by the driver to notify the core that the message in the front of the
2007 * queue is complete and can be removed from the queue.
2008 */
2009void spi_finalize_current_message(struct spi_controller *ctlr)
2010{
2011 struct spi_transfer *xfer;
2012 struct spi_message *mesg;
2013 int ret;
2014
2015 mesg = ctlr->cur_msg;
2016
2017 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
2018 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
2019 ptp_read_system_postts(xfer->ptp_sts);
2020 xfer->ptp_sts_word_post = xfer->len;
2021 }
2022 }
2023
2024 if (unlikely(ctlr->ptp_sts_supported))
2025 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
2026 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
2027
2028 spi_unmap_msg(ctlr, mesg);
2029
2030 /*
2031 * In the prepare_messages callback the SPI bus has the opportunity
2032 * to split a transfer to smaller chunks.
2033 *
2034 * Release the split transfers here since spi_map_msg() is done on
2035 * the split transfers.
2036 */
2037 spi_res_release(ctlr, mesg);
2038
2039 if (mesg->prepared && ctlr->unprepare_message) {
2040 ret = ctlr->unprepare_message(ctlr, mesg);
2041 if (ret) {
2042 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
2043 ret);
2044 }
2045 }
2046
2047 mesg->prepared = false;
2048
2049 WRITE_ONCE(ctlr->cur_msg_incomplete, false);
2050 smp_mb(); /* See __spi_pump_transfer_message()... */
2051 if (READ_ONCE(ctlr->cur_msg_need_completion))
2052 complete(&ctlr->cur_msg_completion);
2053
2054 trace_spi_message_done(mesg);
2055
2056 mesg->state = NULL;
2057 if (mesg->complete)
2058 mesg->complete(mesg->context);
2059}
2060EXPORT_SYMBOL_GPL(spi_finalize_current_message);
2061
2062static int spi_start_queue(struct spi_controller *ctlr)
2063{
2064 unsigned long flags;
2065
2066 spin_lock_irqsave(&ctlr->queue_lock, flags);
2067
2068 if (ctlr->running || ctlr->busy) {
2069 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2070 return -EBUSY;
2071 }
2072
2073 ctlr->running = true;
2074 ctlr->cur_msg = NULL;
2075 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2076
2077 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
2078
2079 return 0;
2080}
2081
2082static int spi_stop_queue(struct spi_controller *ctlr)
2083{
2084 unsigned long flags;
2085 unsigned limit = 500;
2086 int ret = 0;
2087
2088 spin_lock_irqsave(&ctlr->queue_lock, flags);
2089
2090 /*
2091 * This is a bit lame, but is optimized for the common execution path.
2092 * A wait_queue on the ctlr->busy could be used, but then the common
2093 * execution path (pump_messages) would be required to call wake_up or
2094 * friends on every SPI message. Do this instead.
2095 */
2096 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
2097 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2098 usleep_range(10000, 11000);
2099 spin_lock_irqsave(&ctlr->queue_lock, flags);
2100 }
2101
2102 if (!list_empty(&ctlr->queue) || ctlr->busy)
2103 ret = -EBUSY;
2104 else
2105 ctlr->running = false;
2106
2107 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2108
2109 if (ret) {
2110 dev_warn(&ctlr->dev, "could not stop message queue\n");
2111 return ret;
2112 }
2113 return ret;
2114}
2115
2116static int spi_destroy_queue(struct spi_controller *ctlr)
2117{
2118 int ret;
2119
2120 ret = spi_stop_queue(ctlr);
2121
2122 /*
2123 * kthread_flush_worker will block until all work is done.
2124 * If the reason that stop_queue timed out is that the work will never
2125 * finish, then it does no good to call flush/stop thread, so
2126 * return anyway.
2127 */
2128 if (ret) {
2129 dev_err(&ctlr->dev, "problem destroying queue\n");
2130 return ret;
2131 }
2132
2133 kthread_destroy_worker(ctlr->kworker);
2134
2135 return 0;
2136}
2137
2138static int __spi_queued_transfer(struct spi_device *spi,
2139 struct spi_message *msg,
2140 bool need_pump)
2141{
2142 struct spi_controller *ctlr = spi->controller;
2143 unsigned long flags;
2144
2145 spin_lock_irqsave(&ctlr->queue_lock, flags);
2146
2147 if (!ctlr->running) {
2148 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2149 return -ESHUTDOWN;
2150 }
2151 msg->actual_length = 0;
2152 msg->status = -EINPROGRESS;
2153
2154 list_add_tail(&msg->queue, &ctlr->queue);
2155 ctlr->queue_empty = false;
2156 if (!ctlr->busy && need_pump)
2157 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
2158
2159 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2160 return 0;
2161}
2162
2163/**
2164 * spi_queued_transfer - transfer function for queued transfers
2165 * @spi: spi device which is requesting transfer
2166 * @msg: spi message which is to handled is queued to driver queue
2167 *
2168 * Return: zero on success, else a negative error code.
2169 */
2170static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
2171{
2172 return __spi_queued_transfer(spi, msg, true);
2173}
2174
2175static int spi_controller_initialize_queue(struct spi_controller *ctlr)
2176{
2177 int ret;
2178
2179 ctlr->transfer = spi_queued_transfer;
2180 if (!ctlr->transfer_one_message)
2181 ctlr->transfer_one_message = spi_transfer_one_message;
2182
2183 /* Initialize and start queue */
2184 ret = spi_init_queue(ctlr);
2185 if (ret) {
2186 dev_err(&ctlr->dev, "problem initializing queue\n");
2187 goto err_init_queue;
2188 }
2189 ctlr->queued = true;
2190 ret = spi_start_queue(ctlr);
2191 if (ret) {
2192 dev_err(&ctlr->dev, "problem starting queue\n");
2193 goto err_start_queue;
2194 }
2195
2196 return 0;
2197
2198err_start_queue:
2199 spi_destroy_queue(ctlr);
2200err_init_queue:
2201 return ret;
2202}
2203
2204/**
2205 * spi_flush_queue - Send all pending messages in the queue from the callers'
2206 * context
2207 * @ctlr: controller to process queue for
2208 *
2209 * This should be used when one wants to ensure all pending messages have been
2210 * sent before doing something. Is used by the spi-mem code to make sure SPI
2211 * memory operations do not preempt regular SPI transfers that have been queued
2212 * before the spi-mem operation.
2213 */
2214void spi_flush_queue(struct spi_controller *ctlr)
2215{
2216 if (ctlr->transfer == spi_queued_transfer)
2217 __spi_pump_messages(ctlr, false);
2218}
2219
2220/*-------------------------------------------------------------------------*/
2221
2222#if defined(CONFIG_OF)
2223static void of_spi_parse_dt_cs_delay(struct device_node *nc,
2224 struct spi_delay *delay, const char *prop)
2225{
2226 u32 value;
2227
2228 if (!of_property_read_u32(nc, prop, &value)) {
2229 if (value > U16_MAX) {
2230 delay->value = DIV_ROUND_UP(value, 1000);
2231 delay->unit = SPI_DELAY_UNIT_USECS;
2232 } else {
2233 delay->value = value;
2234 delay->unit = SPI_DELAY_UNIT_NSECS;
2235 }
2236 }
2237}
2238
2239static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
2240 struct device_node *nc)
2241{
2242 u32 value;
2243 int rc;
2244
2245 /* Mode (clock phase/polarity/etc.) */
2246 if (of_property_read_bool(nc, "spi-cpha"))
2247 spi->mode |= SPI_CPHA;
2248 if (of_property_read_bool(nc, "spi-cpol"))
2249 spi->mode |= SPI_CPOL;
2250 if (of_property_read_bool(nc, "spi-3wire"))
2251 spi->mode |= SPI_3WIRE;
2252 if (of_property_read_bool(nc, "spi-lsb-first"))
2253 spi->mode |= SPI_LSB_FIRST;
2254 if (of_property_read_bool(nc, "spi-cs-high"))
2255 spi->mode |= SPI_CS_HIGH;
2256
2257 /* Device DUAL/QUAD mode */
2258 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
2259 switch (value) {
2260 case 0:
2261 spi->mode |= SPI_NO_TX;
2262 break;
2263 case 1:
2264 break;
2265 case 2:
2266 spi->mode |= SPI_TX_DUAL;
2267 break;
2268 case 4:
2269 spi->mode |= SPI_TX_QUAD;
2270 break;
2271 case 8:
2272 spi->mode |= SPI_TX_OCTAL;
2273 break;
2274 default:
2275 dev_warn(&ctlr->dev,
2276 "spi-tx-bus-width %d not supported\n",
2277 value);
2278 break;
2279 }
2280 }
2281
2282 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
2283 switch (value) {
2284 case 0:
2285 spi->mode |= SPI_NO_RX;
2286 break;
2287 case 1:
2288 break;
2289 case 2:
2290 spi->mode |= SPI_RX_DUAL;
2291 break;
2292 case 4:
2293 spi->mode |= SPI_RX_QUAD;
2294 break;
2295 case 8:
2296 spi->mode |= SPI_RX_OCTAL;
2297 break;
2298 default:
2299 dev_warn(&ctlr->dev,
2300 "spi-rx-bus-width %d not supported\n",
2301 value);
2302 break;
2303 }
2304 }
2305
2306 if (spi_controller_is_slave(ctlr)) {
2307 if (!of_node_name_eq(nc, "slave")) {
2308 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
2309 nc);
2310 return -EINVAL;
2311 }
2312 return 0;
2313 }
2314
2315 /* Device address */
2316 rc = of_property_read_u32(nc, "reg", &value);
2317 if (rc) {
2318 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
2319 nc, rc);
2320 return rc;
2321 }
2322 spi->chip_select = value;
2323
2324 /* Device speed */
2325 if (!of_property_read_u32(nc, "spi-max-frequency", &value))
2326 spi->max_speed_hz = value;
2327
2328 /* Device CS delays */
2329 of_spi_parse_dt_cs_delay(nc, &spi->cs_setup, "spi-cs-setup-delay-ns");
2330
2331 return 0;
2332}
2333
2334static struct spi_device *
2335of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
2336{
2337 struct spi_device *spi;
2338 int rc;
2339
2340 /* Alloc an spi_device */
2341 spi = spi_alloc_device(ctlr);
2342 if (!spi) {
2343 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
2344 rc = -ENOMEM;
2345 goto err_out;
2346 }
2347
2348 /* Select device driver */
2349 rc = of_modalias_node(nc, spi->modalias,
2350 sizeof(spi->modalias));
2351 if (rc < 0) {
2352 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
2353 goto err_out;
2354 }
2355
2356 rc = of_spi_parse_dt(ctlr, spi, nc);
2357 if (rc)
2358 goto err_out;
2359
2360 /* Store a pointer to the node in the device structure */
2361 of_node_get(nc);
2362 spi->dev.of_node = nc;
2363 spi->dev.fwnode = of_fwnode_handle(nc);
2364
2365 /* Register the new device */
2366 rc = spi_add_device(spi);
2367 if (rc) {
2368 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
2369 goto err_of_node_put;
2370 }
2371
2372 return spi;
2373
2374err_of_node_put:
2375 of_node_put(nc);
2376err_out:
2377 spi_dev_put(spi);
2378 return ERR_PTR(rc);
2379}
2380
2381/**
2382 * of_register_spi_devices() - Register child devices onto the SPI bus
2383 * @ctlr: Pointer to spi_controller device
2384 *
2385 * Registers an spi_device for each child node of controller node which
2386 * represents a valid SPI slave.
2387 */
2388static void of_register_spi_devices(struct spi_controller *ctlr)
2389{
2390 struct spi_device *spi;
2391 struct device_node *nc;
2392
2393 if (!ctlr->dev.of_node)
2394 return;
2395
2396 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2397 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2398 continue;
2399 spi = of_register_spi_device(ctlr, nc);
2400 if (IS_ERR(spi)) {
2401 dev_warn(&ctlr->dev,
2402 "Failed to create SPI device for %pOF\n", nc);
2403 of_node_clear_flag(nc, OF_POPULATED);
2404 }
2405 }
2406}
2407#else
2408static void of_register_spi_devices(struct spi_controller *ctlr) { }
2409#endif
2410
2411/**
2412 * spi_new_ancillary_device() - Register ancillary SPI device
2413 * @spi: Pointer to the main SPI device registering the ancillary device
2414 * @chip_select: Chip Select of the ancillary device
2415 *
2416 * Register an ancillary SPI device; for example some chips have a chip-select
2417 * for normal device usage and another one for setup/firmware upload.
2418 *
2419 * This may only be called from main SPI device's probe routine.
2420 *
2421 * Return: 0 on success; negative errno on failure
2422 */
2423struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
2424 u8 chip_select)
2425{
2426 struct spi_device *ancillary;
2427 int rc = 0;
2428
2429 /* Alloc an spi_device */
2430 ancillary = spi_alloc_device(spi->controller);
2431 if (!ancillary) {
2432 rc = -ENOMEM;
2433 goto err_out;
2434 }
2435
2436 strscpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));
2437
2438 /* Use provided chip-select for ancillary device */
2439 ancillary->chip_select = chip_select;
2440
2441 /* Take over SPI mode/speed from SPI main device */
2442 ancillary->max_speed_hz = spi->max_speed_hz;
2443 ancillary->mode = spi->mode;
2444
2445 /* Register the new device */
2446 rc = spi_add_device_locked(ancillary);
2447 if (rc) {
2448 dev_err(&spi->dev, "failed to register ancillary device\n");
2449 goto err_out;
2450 }
2451
2452 return ancillary;
2453
2454err_out:
2455 spi_dev_put(ancillary);
2456 return ERR_PTR(rc);
2457}
2458EXPORT_SYMBOL_GPL(spi_new_ancillary_device);
2459
2460#ifdef CONFIG_ACPI
2461struct acpi_spi_lookup {
2462 struct spi_controller *ctlr;
2463 u32 max_speed_hz;
2464 u32 mode;
2465 int irq;
2466 u8 bits_per_word;
2467 u8 chip_select;
2468 int n;
2469 int index;
2470};
2471
2472static int acpi_spi_count(struct acpi_resource *ares, void *data)
2473{
2474 struct acpi_resource_spi_serialbus *sb;
2475 int *count = data;
2476
2477 if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
2478 return 1;
2479
2480 sb = &ares->data.spi_serial_bus;
2481 if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_SPI)
2482 return 1;
2483
2484 *count = *count + 1;
2485
2486 return 1;
2487}
2488
2489/**
2490 * acpi_spi_count_resources - Count the number of SpiSerialBus resources
2491 * @adev: ACPI device
2492 *
2493 * Returns the number of SpiSerialBus resources in the ACPI-device's
2494 * resource-list; or a negative error code.
2495 */
2496int acpi_spi_count_resources(struct acpi_device *adev)
2497{
2498 LIST_HEAD(r);
2499 int count = 0;
2500 int ret;
2501
2502 ret = acpi_dev_get_resources(adev, &r, acpi_spi_count, &count);
2503 if (ret < 0)
2504 return ret;
2505
2506 acpi_dev_free_resource_list(&r);
2507
2508 return count;
2509}
2510EXPORT_SYMBOL_GPL(acpi_spi_count_resources);
2511
2512static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2513 struct acpi_spi_lookup *lookup)
2514{
2515 const union acpi_object *obj;
2516
2517 if (!x86_apple_machine)
2518 return;
2519
2520 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2521 && obj->buffer.length >= 4)
2522 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2523
2524 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2525 && obj->buffer.length == 8)
2526 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2527
2528 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2529 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2530 lookup->mode |= SPI_LSB_FIRST;
2531
2532 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2533 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2534 lookup->mode |= SPI_CPOL;
2535
2536 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2537 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2538 lookup->mode |= SPI_CPHA;
2539}
2540
2541static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev);
2542
2543static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2544{
2545 struct acpi_spi_lookup *lookup = data;
2546 struct spi_controller *ctlr = lookup->ctlr;
2547
2548 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2549 struct acpi_resource_spi_serialbus *sb;
2550 acpi_handle parent_handle;
2551 acpi_status status;
2552
2553 sb = &ares->data.spi_serial_bus;
2554 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2555
2556 if (lookup->index != -1 && lookup->n++ != lookup->index)
2557 return 1;
2558
2559 status = acpi_get_handle(NULL,
2560 sb->resource_source.string_ptr,
2561 &parent_handle);
2562
2563 if (ACPI_FAILURE(status))
2564 return -ENODEV;
2565
2566 if (ctlr) {
2567 if (ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
2568 return -ENODEV;
2569 } else {
2570 struct acpi_device *adev;
2571
2572 adev = acpi_fetch_acpi_dev(parent_handle);
2573 if (!adev)
2574 return -ENODEV;
2575
2576 ctlr = acpi_spi_find_controller_by_adev(adev);
2577 if (!ctlr)
2578 return -EPROBE_DEFER;
2579
2580 lookup->ctlr = ctlr;
2581 }
2582
2583 /*
2584 * ACPI DeviceSelection numbering is handled by the
2585 * host controller driver in Windows and can vary
2586 * from driver to driver. In Linux we always expect
2587 * 0 .. max - 1 so we need to ask the driver to
2588 * translate between the two schemes.
2589 */
2590 if (ctlr->fw_translate_cs) {
2591 int cs = ctlr->fw_translate_cs(ctlr,
2592 sb->device_selection);
2593 if (cs < 0)
2594 return cs;
2595 lookup->chip_select = cs;
2596 } else {
2597 lookup->chip_select = sb->device_selection;
2598 }
2599
2600 lookup->max_speed_hz = sb->connection_speed;
2601 lookup->bits_per_word = sb->data_bit_length;
2602
2603 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2604 lookup->mode |= SPI_CPHA;
2605 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2606 lookup->mode |= SPI_CPOL;
2607 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2608 lookup->mode |= SPI_CS_HIGH;
2609 }
2610 } else if (lookup->irq < 0) {
2611 struct resource r;
2612
2613 if (acpi_dev_resource_interrupt(ares, 0, &r))
2614 lookup->irq = r.start;
2615 }
2616
2617 /* Always tell the ACPI core to skip this resource */
2618 return 1;
2619}
2620
2621/**
2622 * acpi_spi_device_alloc - Allocate a spi device, and fill it in with ACPI information
2623 * @ctlr: controller to which the spi device belongs
2624 * @adev: ACPI Device for the spi device
2625 * @index: Index of the spi resource inside the ACPI Node
2626 *
2627 * This should be used to allocate a new spi device from and ACPI Node.
2628 * The caller is responsible for calling spi_add_device to register the spi device.
2629 *
2630 * If ctlr is set to NULL, the Controller for the spi device will be looked up
2631 * using the resource.
2632 * If index is set to -1, index is not used.
2633 * Note: If index is -1, ctlr must be set.
2634 *
2635 * Return: a pointer to the new device, or ERR_PTR on error.
2636 */
2637struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
2638 struct acpi_device *adev,
2639 int index)
2640{
2641 acpi_handle parent_handle = NULL;
2642 struct list_head resource_list;
2643 struct acpi_spi_lookup lookup = {};
2644 struct spi_device *spi;
2645 int ret;
2646
2647 if (!ctlr && index == -1)
2648 return ERR_PTR(-EINVAL);
2649
2650 lookup.ctlr = ctlr;
2651 lookup.irq = -1;
2652 lookup.index = index;
2653 lookup.n = 0;
2654
2655 INIT_LIST_HEAD(&resource_list);
2656 ret = acpi_dev_get_resources(adev, &resource_list,
2657 acpi_spi_add_resource, &lookup);
2658 acpi_dev_free_resource_list(&resource_list);
2659
2660 if (ret < 0)
2661 /* Found SPI in _CRS but it points to another controller */
2662 return ERR_PTR(ret);
2663
2664 if (!lookup.max_speed_hz &&
2665 ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
2666 ACPI_HANDLE(lookup.ctlr->dev.parent) == parent_handle) {
2667 /* Apple does not use _CRS but nested devices for SPI slaves */
2668 acpi_spi_parse_apple_properties(adev, &lookup);
2669 }
2670
2671 if (!lookup.max_speed_hz)
2672 return ERR_PTR(-ENODEV);
2673
2674 spi = spi_alloc_device(lookup.ctlr);
2675 if (!spi) {
2676 dev_err(&lookup.ctlr->dev, "failed to allocate SPI device for %s\n",
2677 dev_name(&adev->dev));
2678 return ERR_PTR(-ENOMEM);
2679 }
2680
2681 ACPI_COMPANION_SET(&spi->dev, adev);
2682 spi->max_speed_hz = lookup.max_speed_hz;
2683 spi->mode |= lookup.mode;
2684 spi->irq = lookup.irq;
2685 spi->bits_per_word = lookup.bits_per_word;
2686 spi->chip_select = lookup.chip_select;
2687
2688 return spi;
2689}
2690EXPORT_SYMBOL_GPL(acpi_spi_device_alloc);
2691
2692static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2693 struct acpi_device *adev)
2694{
2695 struct spi_device *spi;
2696
2697 if (acpi_bus_get_status(adev) || !adev->status.present ||
2698 acpi_device_enumerated(adev))
2699 return AE_OK;
2700
2701 spi = acpi_spi_device_alloc(ctlr, adev, -1);
2702 if (IS_ERR(spi)) {
2703 if (PTR_ERR(spi) == -ENOMEM)
2704 return AE_NO_MEMORY;
2705 else
2706 return AE_OK;
2707 }
2708
2709 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2710 sizeof(spi->modalias));
2711
2712 if (spi->irq < 0)
2713 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
2714
2715 acpi_device_set_enumerated(adev);
2716
2717 adev->power.flags.ignore_parent = true;
2718 if (spi_add_device(spi)) {
2719 adev->power.flags.ignore_parent = false;
2720 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2721 dev_name(&adev->dev));
2722 spi_dev_put(spi);
2723 }
2724
2725 return AE_OK;
2726}
2727
2728static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2729 void *data, void **return_value)
2730{
2731 struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
2732 struct spi_controller *ctlr = data;
2733
2734 if (!adev)
2735 return AE_OK;
2736
2737 return acpi_register_spi_device(ctlr, adev);
2738}
2739
2740#define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2741
2742static void acpi_register_spi_devices(struct spi_controller *ctlr)
2743{
2744 acpi_status status;
2745 acpi_handle handle;
2746
2747 handle = ACPI_HANDLE(ctlr->dev.parent);
2748 if (!handle)
2749 return;
2750
2751 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2752 SPI_ACPI_ENUMERATE_MAX_DEPTH,
2753 acpi_spi_add_device, NULL, ctlr, NULL);
2754 if (ACPI_FAILURE(status))
2755 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2756}
2757#else
2758static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2759#endif /* CONFIG_ACPI */
2760
2761static void spi_controller_release(struct device *dev)
2762{
2763 struct spi_controller *ctlr;
2764
2765 ctlr = container_of(dev, struct spi_controller, dev);
2766 kfree(ctlr);
2767}
2768
2769static struct class spi_master_class = {
2770 .name = "spi_master",
2771 .owner = THIS_MODULE,
2772 .dev_release = spi_controller_release,
2773 .dev_groups = spi_master_groups,
2774};
2775
2776#ifdef CONFIG_SPI_SLAVE
2777/**
2778 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2779 * controller
2780 * @spi: device used for the current transfer
2781 */
2782int spi_slave_abort(struct spi_device *spi)
2783{
2784 struct spi_controller *ctlr = spi->controller;
2785
2786 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
2787 return ctlr->slave_abort(ctlr);
2788
2789 return -ENOTSUPP;
2790}
2791EXPORT_SYMBOL_GPL(spi_slave_abort);
2792
2793int spi_target_abort(struct spi_device *spi)
2794{
2795 struct spi_controller *ctlr = spi->controller;
2796
2797 if (spi_controller_is_target(ctlr) && ctlr->target_abort)
2798 return ctlr->target_abort(ctlr);
2799
2800 return -ENOTSUPP;
2801}
2802EXPORT_SYMBOL_GPL(spi_target_abort);
2803
2804static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2805 char *buf)
2806{
2807 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2808 dev);
2809 struct device *child;
2810
2811 child = device_find_any_child(&ctlr->dev);
2812 return sprintf(buf, "%s\n",
2813 child ? to_spi_device(child)->modalias : NULL);
2814}
2815
2816static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
2817 const char *buf, size_t count)
2818{
2819 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2820 dev);
2821 struct spi_device *spi;
2822 struct device *child;
2823 char name[32];
2824 int rc;
2825
2826 rc = sscanf(buf, "%31s", name);
2827 if (rc != 1 || !name[0])
2828 return -EINVAL;
2829
2830 child = device_find_any_child(&ctlr->dev);
2831 if (child) {
2832 /* Remove registered slave */
2833 device_unregister(child);
2834 put_device(child);
2835 }
2836
2837 if (strcmp(name, "(null)")) {
2838 /* Register new slave */
2839 spi = spi_alloc_device(ctlr);
2840 if (!spi)
2841 return -ENOMEM;
2842
2843 strscpy(spi->modalias, name, sizeof(spi->modalias));
2844
2845 rc = spi_add_device(spi);
2846 if (rc) {
2847 spi_dev_put(spi);
2848 return rc;
2849 }
2850 }
2851
2852 return count;
2853}
2854
2855static DEVICE_ATTR_RW(slave);
2856
2857static struct attribute *spi_slave_attrs[] = {
2858 &dev_attr_slave.attr,
2859 NULL,
2860};
2861
2862static const struct attribute_group spi_slave_group = {
2863 .attrs = spi_slave_attrs,
2864};
2865
2866static const struct attribute_group *spi_slave_groups[] = {
2867 &spi_controller_statistics_group,
2868 &spi_slave_group,
2869 NULL,
2870};
2871
2872static struct class spi_slave_class = {
2873 .name = "spi_slave",
2874 .owner = THIS_MODULE,
2875 .dev_release = spi_controller_release,
2876 .dev_groups = spi_slave_groups,
2877};
2878#else
2879extern struct class spi_slave_class; /* dummy */
2880#endif
2881
2882/**
2883 * __spi_alloc_controller - allocate an SPI master or slave controller
2884 * @dev: the controller, possibly using the platform_bus
2885 * @size: how much zeroed driver-private data to allocate; the pointer to this
2886 * memory is in the driver_data field of the returned device, accessible
2887 * with spi_controller_get_devdata(); the memory is cacheline aligned;
2888 * drivers granting DMA access to portions of their private data need to
2889 * round up @size using ALIGN(size, dma_get_cache_alignment()).
2890 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2891 * slave (true) controller
2892 * Context: can sleep
2893 *
2894 * This call is used only by SPI controller drivers, which are the
2895 * only ones directly touching chip registers. It's how they allocate
2896 * an spi_controller structure, prior to calling spi_register_controller().
2897 *
2898 * This must be called from context that can sleep.
2899 *
2900 * The caller is responsible for assigning the bus number and initializing the
2901 * controller's methods before calling spi_register_controller(); and (after
2902 * errors adding the device) calling spi_controller_put() to prevent a memory
2903 * leak.
2904 *
2905 * Return: the SPI controller structure on success, else NULL.
2906 */
2907struct spi_controller *__spi_alloc_controller(struct device *dev,
2908 unsigned int size, bool slave)
2909{
2910 struct spi_controller *ctlr;
2911 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
2912
2913 if (!dev)
2914 return NULL;
2915
2916 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
2917 if (!ctlr)
2918 return NULL;
2919
2920 device_initialize(&ctlr->dev);
2921 INIT_LIST_HEAD(&ctlr->queue);
2922 spin_lock_init(&ctlr->queue_lock);
2923 spin_lock_init(&ctlr->bus_lock_spinlock);
2924 mutex_init(&ctlr->bus_lock_mutex);
2925 mutex_init(&ctlr->io_mutex);
2926 mutex_init(&ctlr->add_lock);
2927 ctlr->bus_num = -1;
2928 ctlr->num_chipselect = 1;
2929 ctlr->slave = slave;
2930 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2931 ctlr->dev.class = &spi_slave_class;
2932 else
2933 ctlr->dev.class = &spi_master_class;
2934 ctlr->dev.parent = dev;
2935 pm_suspend_ignore_children(&ctlr->dev, true);
2936 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
2937
2938 return ctlr;
2939}
2940EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2941
2942static void devm_spi_release_controller(struct device *dev, void *ctlr)
2943{
2944 spi_controller_put(*(struct spi_controller **)ctlr);
2945}
2946
2947/**
2948 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
2949 * @dev: physical device of SPI controller
2950 * @size: how much zeroed driver-private data to allocate
2951 * @slave: whether to allocate an SPI master (false) or SPI slave (true)
2952 * Context: can sleep
2953 *
2954 * Allocate an SPI controller and automatically release a reference on it
2955 * when @dev is unbound from its driver. Drivers are thus relieved from
2956 * having to call spi_controller_put().
2957 *
2958 * The arguments to this function are identical to __spi_alloc_controller().
2959 *
2960 * Return: the SPI controller structure on success, else NULL.
2961 */
2962struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
2963 unsigned int size,
2964 bool slave)
2965{
2966 struct spi_controller **ptr, *ctlr;
2967
2968 ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),
2969 GFP_KERNEL);
2970 if (!ptr)
2971 return NULL;
2972
2973 ctlr = __spi_alloc_controller(dev, size, slave);
2974 if (ctlr) {
2975 ctlr->devm_allocated = true;
2976 *ptr = ctlr;
2977 devres_add(dev, ptr);
2978 } else {
2979 devres_free(ptr);
2980 }
2981
2982 return ctlr;
2983}
2984EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);
2985
2986/**
2987 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2988 * @ctlr: The SPI master to grab GPIO descriptors for
2989 */
2990static int spi_get_gpio_descs(struct spi_controller *ctlr)
2991{
2992 int nb, i;
2993 struct gpio_desc **cs;
2994 struct device *dev = &ctlr->dev;
2995 unsigned long native_cs_mask = 0;
2996 unsigned int num_cs_gpios = 0;
2997
2998 nb = gpiod_count(dev, "cs");
2999 if (nb < 0) {
3000 /* No GPIOs at all is fine, else return the error */
3001 if (nb == -ENOENT)
3002 return 0;
3003 return nb;
3004 }
3005
3006 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
3007
3008 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
3009 GFP_KERNEL);
3010 if (!cs)
3011 return -ENOMEM;
3012 ctlr->cs_gpiods = cs;
3013
3014 for (i = 0; i < nb; i++) {
3015 /*
3016 * Most chipselects are active low, the inverted
3017 * semantics are handled by special quirks in gpiolib,
3018 * so initializing them GPIOD_OUT_LOW here means
3019 * "unasserted", in most cases this will drive the physical
3020 * line high.
3021 */
3022 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
3023 GPIOD_OUT_LOW);
3024 if (IS_ERR(cs[i]))
3025 return PTR_ERR(cs[i]);
3026
3027 if (cs[i]) {
3028 /*
3029 * If we find a CS GPIO, name it after the device and
3030 * chip select line.
3031 */
3032 char *gpioname;
3033
3034 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
3035 dev_name(dev), i);
3036 if (!gpioname)
3037 return -ENOMEM;
3038 gpiod_set_consumer_name(cs[i], gpioname);
3039 num_cs_gpios++;
3040 continue;
3041 }
3042
3043 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
3044 dev_err(dev, "Invalid native chip select %d\n", i);
3045 return -EINVAL;
3046 }
3047 native_cs_mask |= BIT(i);
3048 }
3049
3050 ctlr->unused_native_cs = ffs(~native_cs_mask) - 1;
3051
3052 if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios &&
3053 ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {
3054 dev_err(dev, "No unused native chip select available\n");
3055 return -EINVAL;
3056 }
3057
3058 return 0;
3059}
3060
3061static int spi_controller_check_ops(struct spi_controller *ctlr)
3062{
3063 /*
3064 * The controller may implement only the high-level SPI-memory like
3065 * operations if it does not support regular SPI transfers, and this is
3066 * valid use case.
3067 * If ->mem_ops is NULL, we request that at least one of the
3068 * ->transfer_xxx() method be implemented.
3069 */
3070 if (ctlr->mem_ops) {
3071 if (!ctlr->mem_ops->exec_op)
3072 return -EINVAL;
3073 } else if (!ctlr->transfer && !ctlr->transfer_one &&
3074 !ctlr->transfer_one_message) {
3075 return -EINVAL;
3076 }
3077
3078 return 0;
3079}
3080
3081/**
3082 * spi_register_controller - register SPI master or slave controller
3083 * @ctlr: initialized master, originally from spi_alloc_master() or
3084 * spi_alloc_slave()
3085 * Context: can sleep
3086 *
3087 * SPI controllers connect to their drivers using some non-SPI bus,
3088 * such as the platform bus. The final stage of probe() in that code
3089 * includes calling spi_register_controller() to hook up to this SPI bus glue.
3090 *
3091 * SPI controllers use board specific (often SOC specific) bus numbers,
3092 * and board-specific addressing for SPI devices combines those numbers
3093 * with chip select numbers. Since SPI does not directly support dynamic
3094 * device identification, boards need configuration tables telling which
3095 * chip is at which address.
3096 *
3097 * This must be called from context that can sleep. It returns zero on
3098 * success, else a negative error code (dropping the controller's refcount).
3099 * After a successful return, the caller is responsible for calling
3100 * spi_unregister_controller().
3101 *
3102 * Return: zero on success, else a negative error code.
3103 */
3104int spi_register_controller(struct spi_controller *ctlr)
3105{
3106 struct device *dev = ctlr->dev.parent;
3107 struct boardinfo *bi;
3108 int status;
3109 int id, first_dynamic;
3110
3111 if (!dev)
3112 return -ENODEV;
3113
3114 /*
3115 * Make sure all necessary hooks are implemented before registering
3116 * the SPI controller.
3117 */
3118 status = spi_controller_check_ops(ctlr);
3119 if (status)
3120 return status;
3121
3122 if (ctlr->bus_num >= 0) {
3123 /* Devices with a fixed bus num must check-in with the num */
3124 mutex_lock(&board_lock);
3125 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
3126 ctlr->bus_num + 1, GFP_KERNEL);
3127 mutex_unlock(&board_lock);
3128 if (WARN(id < 0, "couldn't get idr"))
3129 return id == -ENOSPC ? -EBUSY : id;
3130 ctlr->bus_num = id;
3131 } else if (ctlr->dev.of_node) {
3132 /* Allocate dynamic bus number using Linux idr */
3133 id = of_alias_get_id(ctlr->dev.of_node, "spi");
3134 if (id >= 0) {
3135 ctlr->bus_num = id;
3136 mutex_lock(&board_lock);
3137 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
3138 ctlr->bus_num + 1, GFP_KERNEL);
3139 mutex_unlock(&board_lock);
3140 if (WARN(id < 0, "couldn't get idr"))
3141 return id == -ENOSPC ? -EBUSY : id;
3142 }
3143 }
3144 if (ctlr->bus_num < 0) {
3145 first_dynamic = of_alias_get_highest_id("spi");
3146 if (first_dynamic < 0)
3147 first_dynamic = 0;
3148 else
3149 first_dynamic++;
3150
3151 mutex_lock(&board_lock);
3152 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
3153 0, GFP_KERNEL);
3154 mutex_unlock(&board_lock);
3155 if (WARN(id < 0, "couldn't get idr"))
3156 return id;
3157 ctlr->bus_num = id;
3158 }
3159 ctlr->bus_lock_flag = 0;
3160 init_completion(&ctlr->xfer_completion);
3161 init_completion(&ctlr->cur_msg_completion);
3162 if (!ctlr->max_dma_len)
3163 ctlr->max_dma_len = INT_MAX;
3164
3165 /*
3166 * Register the device, then userspace will see it.
3167 * Registration fails if the bus ID is in use.
3168 */
3169 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
3170
3171 if (!spi_controller_is_slave(ctlr) && ctlr->use_gpio_descriptors) {
3172 status = spi_get_gpio_descs(ctlr);
3173 if (status)
3174 goto free_bus_id;
3175 /*
3176 * A controller using GPIO descriptors always
3177 * supports SPI_CS_HIGH if need be.
3178 */
3179 ctlr->mode_bits |= SPI_CS_HIGH;
3180 }
3181
3182 /*
3183 * Even if it's just one always-selected device, there must
3184 * be at least one chipselect.
3185 */
3186 if (!ctlr->num_chipselect) {
3187 status = -EINVAL;
3188 goto free_bus_id;
3189 }
3190
3191 /* Setting last_cs to -1 means no chip selected */
3192 ctlr->last_cs = -1;
3193
3194 status = device_add(&ctlr->dev);
3195 if (status < 0)
3196 goto free_bus_id;
3197 dev_dbg(dev, "registered %s %s\n",
3198 spi_controller_is_slave(ctlr) ? "slave" : "master",
3199 dev_name(&ctlr->dev));
3200
3201 /*
3202 * If we're using a queued driver, start the queue. Note that we don't
3203 * need the queueing logic if the driver is only supporting high-level
3204 * memory operations.
3205 */
3206 if (ctlr->transfer) {
3207 dev_info(dev, "controller is unqueued, this is deprecated\n");
3208 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
3209 status = spi_controller_initialize_queue(ctlr);
3210 if (status) {
3211 device_del(&ctlr->dev);
3212 goto free_bus_id;
3213 }
3214 }
3215 /* Add statistics */
3216 ctlr->pcpu_statistics = spi_alloc_pcpu_stats(dev);
3217 if (!ctlr->pcpu_statistics) {
3218 dev_err(dev, "Error allocating per-cpu statistics\n");
3219 status = -ENOMEM;
3220 goto destroy_queue;
3221 }
3222
3223 mutex_lock(&board_lock);
3224 list_add_tail(&ctlr->list, &spi_controller_list);
3225 list_for_each_entry(bi, &board_list, list)
3226 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
3227 mutex_unlock(&board_lock);
3228
3229 /* Register devices from the device tree and ACPI */
3230 of_register_spi_devices(ctlr);
3231 acpi_register_spi_devices(ctlr);
3232 return status;
3233
3234destroy_queue:
3235 spi_destroy_queue(ctlr);
3236free_bus_id:
3237 mutex_lock(&board_lock);
3238 idr_remove(&spi_master_idr, ctlr->bus_num);
3239 mutex_unlock(&board_lock);
3240 return status;
3241}
3242EXPORT_SYMBOL_GPL(spi_register_controller);
3243
3244static void devm_spi_unregister(struct device *dev, void *res)
3245{
3246 spi_unregister_controller(*(struct spi_controller **)res);
3247}
3248
3249/**
3250 * devm_spi_register_controller - register managed SPI master or slave
3251 * controller
3252 * @dev: device managing SPI controller
3253 * @ctlr: initialized controller, originally from spi_alloc_master() or
3254 * spi_alloc_slave()
3255 * Context: can sleep
3256 *
3257 * Register a SPI device as with spi_register_controller() which will
3258 * automatically be unregistered and freed.
3259 *
3260 * Return: zero on success, else a negative error code.
3261 */
3262int devm_spi_register_controller(struct device *dev,
3263 struct spi_controller *ctlr)
3264{
3265 struct spi_controller **ptr;
3266 int ret;
3267
3268 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
3269 if (!ptr)
3270 return -ENOMEM;
3271
3272 ret = spi_register_controller(ctlr);
3273 if (!ret) {
3274 *ptr = ctlr;
3275 devres_add(dev, ptr);
3276 } else {
3277 devres_free(ptr);
3278 }
3279
3280 return ret;
3281}
3282EXPORT_SYMBOL_GPL(devm_spi_register_controller);
3283
3284static int __unregister(struct device *dev, void *null)
3285{
3286 spi_unregister_device(to_spi_device(dev));
3287 return 0;
3288}
3289
3290/**
3291 * spi_unregister_controller - unregister SPI master or slave controller
3292 * @ctlr: the controller being unregistered
3293 * Context: can sleep
3294 *
3295 * This call is used only by SPI controller drivers, which are the
3296 * only ones directly touching chip registers.
3297 *
3298 * This must be called from context that can sleep.
3299 *
3300 * Note that this function also drops a reference to the controller.
3301 */
3302void spi_unregister_controller(struct spi_controller *ctlr)
3303{
3304 struct spi_controller *found;
3305 int id = ctlr->bus_num;
3306
3307 /* Prevent addition of new devices, unregister existing ones */
3308 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
3309 mutex_lock(&ctlr->add_lock);
3310
3311 device_for_each_child(&ctlr->dev, NULL, __unregister);
3312
3313 /* First make sure that this controller was ever added */
3314 mutex_lock(&board_lock);
3315 found = idr_find(&spi_master_idr, id);
3316 mutex_unlock(&board_lock);
3317 if (ctlr->queued) {
3318 if (spi_destroy_queue(ctlr))
3319 dev_err(&ctlr->dev, "queue remove failed\n");
3320 }
3321 mutex_lock(&board_lock);
3322 list_del(&ctlr->list);
3323 mutex_unlock(&board_lock);
3324
3325 device_del(&ctlr->dev);
3326
3327 /* Free bus id */
3328 mutex_lock(&board_lock);
3329 if (found == ctlr)
3330 idr_remove(&spi_master_idr, id);
3331 mutex_unlock(&board_lock);
3332
3333 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
3334 mutex_unlock(&ctlr->add_lock);
3335
3336 /* Release the last reference on the controller if its driver
3337 * has not yet been converted to devm_spi_alloc_master/slave().
3338 */
3339 if (!ctlr->devm_allocated)
3340 put_device(&ctlr->dev);
3341}
3342EXPORT_SYMBOL_GPL(spi_unregister_controller);
3343
3344int spi_controller_suspend(struct spi_controller *ctlr)
3345{
3346 int ret;
3347
3348 /* Basically no-ops for non-queued controllers */
3349 if (!ctlr->queued)
3350 return 0;
3351
3352 ret = spi_stop_queue(ctlr);
3353 if (ret)
3354 dev_err(&ctlr->dev, "queue stop failed\n");
3355
3356 return ret;
3357}
3358EXPORT_SYMBOL_GPL(spi_controller_suspend);
3359
3360int spi_controller_resume(struct spi_controller *ctlr)
3361{
3362 int ret;
3363
3364 if (!ctlr->queued)
3365 return 0;
3366
3367 ret = spi_start_queue(ctlr);
3368 if (ret)
3369 dev_err(&ctlr->dev, "queue restart failed\n");
3370
3371 return ret;
3372}
3373EXPORT_SYMBOL_GPL(spi_controller_resume);
3374
3375/*-------------------------------------------------------------------------*/
3376
3377/* Core methods for spi_message alterations */
3378
3379static void __spi_replace_transfers_release(struct spi_controller *ctlr,
3380 struct spi_message *msg,
3381 void *res)
3382{
3383 struct spi_replaced_transfers *rxfer = res;
3384 size_t i;
3385
3386 /* Call extra callback if requested */
3387 if (rxfer->release)
3388 rxfer->release(ctlr, msg, res);
3389
3390 /* Insert replaced transfers back into the message */
3391 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
3392
3393 /* Remove the formerly inserted entries */
3394 for (i = 0; i < rxfer->inserted; i++)
3395 list_del(&rxfer->inserted_transfers[i].transfer_list);
3396}
3397
3398/**
3399 * spi_replace_transfers - replace transfers with several transfers
3400 * and register change with spi_message.resources
3401 * @msg: the spi_message we work upon
3402 * @xfer_first: the first spi_transfer we want to replace
3403 * @remove: number of transfers to remove
3404 * @insert: the number of transfers we want to insert instead
3405 * @release: extra release code necessary in some circumstances
3406 * @extradatasize: extra data to allocate (with alignment guarantees
3407 * of struct @spi_transfer)
3408 * @gfp: gfp flags
3409 *
3410 * Returns: pointer to @spi_replaced_transfers,
3411 * PTR_ERR(...) in case of errors.
3412 */
3413static struct spi_replaced_transfers *spi_replace_transfers(
3414 struct spi_message *msg,
3415 struct spi_transfer *xfer_first,
3416 size_t remove,
3417 size_t insert,
3418 spi_replaced_release_t release,
3419 size_t extradatasize,
3420 gfp_t gfp)
3421{
3422 struct spi_replaced_transfers *rxfer;
3423 struct spi_transfer *xfer;
3424 size_t i;
3425
3426 /* Allocate the structure using spi_res */
3427 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
3428 struct_size(rxfer, inserted_transfers, insert)
3429 + extradatasize,
3430 gfp);
3431 if (!rxfer)
3432 return ERR_PTR(-ENOMEM);
3433
3434 /* The release code to invoke before running the generic release */
3435 rxfer->release = release;
3436
3437 /* Assign extradata */
3438 if (extradatasize)
3439 rxfer->extradata =
3440 &rxfer->inserted_transfers[insert];
3441
3442 /* Init the replaced_transfers list */
3443 INIT_LIST_HEAD(&rxfer->replaced_transfers);
3444
3445 /*
3446 * Assign the list_entry after which we should reinsert
3447 * the @replaced_transfers - it may be spi_message.messages!
3448 */
3449 rxfer->replaced_after = xfer_first->transfer_list.prev;
3450
3451 /* Remove the requested number of transfers */
3452 for (i = 0; i < remove; i++) {
3453 /*
3454 * If the entry after replaced_after it is msg->transfers
3455 * then we have been requested to remove more transfers
3456 * than are in the list.
3457 */
3458 if (rxfer->replaced_after->next == &msg->transfers) {
3459 dev_err(&msg->spi->dev,
3460 "requested to remove more spi_transfers than are available\n");
3461 /* Insert replaced transfers back into the message */
3462 list_splice(&rxfer->replaced_transfers,
3463 rxfer->replaced_after);
3464
3465 /* Free the spi_replace_transfer structure... */
3466 spi_res_free(rxfer);
3467
3468 /* ...and return with an error */
3469 return ERR_PTR(-EINVAL);
3470 }
3471
3472 /*
3473 * Remove the entry after replaced_after from list of
3474 * transfers and add it to list of replaced_transfers.
3475 */
3476 list_move_tail(rxfer->replaced_after->next,
3477 &rxfer->replaced_transfers);
3478 }
3479
3480 /*
3481 * Create copy of the given xfer with identical settings
3482 * based on the first transfer to get removed.
3483 */
3484 for (i = 0; i < insert; i++) {
3485 /* We need to run in reverse order */
3486 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3487
3488 /* Copy all spi_transfer data */
3489 memcpy(xfer, xfer_first, sizeof(*xfer));
3490
3491 /* Add to list */
3492 list_add(&xfer->transfer_list, rxfer->replaced_after);
3493
3494 /* Clear cs_change and delay for all but the last */
3495 if (i) {
3496 xfer->cs_change = false;
3497 xfer->delay.value = 0;
3498 }
3499 }
3500
3501 /* Set up inserted... */
3502 rxfer->inserted = insert;
3503
3504 /* ...and register it with spi_res/spi_message */
3505 spi_res_add(msg, rxfer);
3506
3507 return rxfer;
3508}
3509
3510static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3511 struct spi_message *msg,
3512 struct spi_transfer **xferp,
3513 size_t maxsize,
3514 gfp_t gfp)
3515{
3516 struct spi_transfer *xfer = *xferp, *xfers;
3517 struct spi_replaced_transfers *srt;
3518 size_t offset;
3519 size_t count, i;
3520
3521 /* Calculate how many we have to replace */
3522 count = DIV_ROUND_UP(xfer->len, maxsize);
3523
3524 /* Create replacement */
3525 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
3526 if (IS_ERR(srt))
3527 return PTR_ERR(srt);
3528 xfers = srt->inserted_transfers;
3529
3530 /*
3531 * Now handle each of those newly inserted spi_transfers.
3532 * Note that the replacements spi_transfers all are preset
3533 * to the same values as *xferp, so tx_buf, rx_buf and len
3534 * are all identical (as well as most others)
3535 * so we just have to fix up len and the pointers.
3536 *
3537 * This also includes support for the depreciated
3538 * spi_message.is_dma_mapped interface.
3539 */
3540
3541 /*
3542 * The first transfer just needs the length modified, so we
3543 * run it outside the loop.
3544 */
3545 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3546
3547 /* All the others need rx_buf/tx_buf also set */
3548 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3549 /* Update rx_buf, tx_buf and dma */
3550 if (xfers[i].rx_buf)
3551 xfers[i].rx_buf += offset;
3552 if (xfers[i].rx_dma)
3553 xfers[i].rx_dma += offset;
3554 if (xfers[i].tx_buf)
3555 xfers[i].tx_buf += offset;
3556 if (xfers[i].tx_dma)
3557 xfers[i].tx_dma += offset;
3558
3559 /* Update length */
3560 xfers[i].len = min(maxsize, xfers[i].len - offset);
3561 }
3562
3563 /*
3564 * We set up xferp to the last entry we have inserted,
3565 * so that we skip those already split transfers.
3566 */
3567 *xferp = &xfers[count - 1];
3568
3569 /* Increment statistics counters */
3570 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics,
3571 transfers_split_maxsize);
3572 SPI_STATISTICS_INCREMENT_FIELD(msg->spi->pcpu_statistics,
3573 transfers_split_maxsize);
3574
3575 return 0;
3576}
3577
3578/**
3579 * spi_split_transfers_maxsize - split spi transfers into multiple transfers
3580 * when an individual transfer exceeds a
3581 * certain size
3582 * @ctlr: the @spi_controller for this transfer
3583 * @msg: the @spi_message to transform
3584 * @maxsize: the maximum when to apply this
3585 * @gfp: GFP allocation flags
3586 *
3587 * Return: status of transformation
3588 */
3589int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3590 struct spi_message *msg,
3591 size_t maxsize,
3592 gfp_t gfp)
3593{
3594 struct spi_transfer *xfer;
3595 int ret;
3596
3597 /*
3598 * Iterate over the transfer_list,
3599 * but note that xfer is advanced to the last transfer inserted
3600 * to avoid checking sizes again unnecessarily (also xfer does
3601 * potentially belong to a different list by the time the
3602 * replacement has happened).
3603 */
3604 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3605 if (xfer->len > maxsize) {
3606 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3607 maxsize, gfp);
3608 if (ret)
3609 return ret;
3610 }
3611 }
3612
3613 return 0;
3614}
3615EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3616
3617/*-------------------------------------------------------------------------*/
3618
3619/* Core methods for SPI controller protocol drivers. Some of the
3620 * other core methods are currently defined as inline functions.
3621 */
3622
3623static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3624 u8 bits_per_word)
3625{
3626 if (ctlr->bits_per_word_mask) {
3627 /* Only 32 bits fit in the mask */
3628 if (bits_per_word > 32)
3629 return -EINVAL;
3630 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3631 return -EINVAL;
3632 }
3633
3634 return 0;
3635}
3636
3637/**
3638 * spi_set_cs_timing - configure CS setup, hold, and inactive delays
3639 * @spi: the device that requires specific CS timing configuration
3640 *
3641 * Return: zero on success, else a negative error code.
3642 */
3643static int spi_set_cs_timing(struct spi_device *spi)
3644{
3645 struct device *parent = spi->controller->dev.parent;
3646 int status = 0;
3647
3648 if (spi->controller->set_cs_timing && !spi->cs_gpiod) {
3649 if (spi->controller->auto_runtime_pm) {
3650 status = pm_runtime_get_sync(parent);
3651 if (status < 0) {
3652 pm_runtime_put_noidle(parent);
3653 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3654 status);
3655 return status;
3656 }
3657
3658 status = spi->controller->set_cs_timing(spi);
3659 pm_runtime_mark_last_busy(parent);
3660 pm_runtime_put_autosuspend(parent);
3661 } else {
3662 status = spi->controller->set_cs_timing(spi);
3663 }
3664 }
3665 return status;
3666}
3667
3668/**
3669 * spi_setup - setup SPI mode and clock rate
3670 * @spi: the device whose settings are being modified
3671 * Context: can sleep, and no requests are queued to the device
3672 *
3673 * SPI protocol drivers may need to update the transfer mode if the
3674 * device doesn't work with its default. They may likewise need
3675 * to update clock rates or word sizes from initial values. This function
3676 * changes those settings, and must be called from a context that can sleep.
3677 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3678 * effect the next time the device is selected and data is transferred to
3679 * or from it. When this function returns, the spi device is deselected.
3680 *
3681 * Note that this call will fail if the protocol driver specifies an option
3682 * that the underlying controller or its driver does not support. For
3683 * example, not all hardware supports wire transfers using nine bit words,
3684 * LSB-first wire encoding, or active-high chipselects.
3685 *
3686 * Return: zero on success, else a negative error code.
3687 */
3688int spi_setup(struct spi_device *spi)
3689{
3690 unsigned bad_bits, ugly_bits;
3691 int status = 0;
3692
3693 /*
3694 * Check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
3695 * are set at the same time.
3696 */
3697 if ((hweight_long(spi->mode &
3698 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
3699 (hweight_long(spi->mode &
3700 (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
3701 dev_err(&spi->dev,
3702 "setup: can not select any two of dual, quad and no-rx/tx at the same time\n");
3703 return -EINVAL;
3704 }
3705 /* If it is SPI_3WIRE mode, DUAL and QUAD should be forbidden */
3706 if ((spi->mode & SPI_3WIRE) && (spi->mode &
3707 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3708 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3709 return -EINVAL;
3710 /*
3711 * Help drivers fail *cleanly* when they need options
3712 * that aren't supported with their current controller.
3713 * SPI_CS_WORD has a fallback software implementation,
3714 * so it is ignored here.
3715 */
3716 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
3717 SPI_NO_TX | SPI_NO_RX);
3718 ugly_bits = bad_bits &
3719 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3720 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3721 if (ugly_bits) {
3722 dev_warn(&spi->dev,
3723 "setup: ignoring unsupported mode bits %x\n",
3724 ugly_bits);
3725 spi->mode &= ~ugly_bits;
3726 bad_bits &= ~ugly_bits;
3727 }
3728 if (bad_bits) {
3729 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3730 bad_bits);
3731 return -EINVAL;
3732 }
3733
3734 if (!spi->bits_per_word) {
3735 spi->bits_per_word = 8;
3736 } else {
3737 /*
3738 * Some controllers may not support the default 8 bits-per-word
3739 * so only perform the check when this is explicitly provided.
3740 */
3741 status = __spi_validate_bits_per_word(spi->controller,
3742 spi->bits_per_word);
3743 if (status)
3744 return status;
3745 }
3746
3747 if (spi->controller->max_speed_hz &&
3748 (!spi->max_speed_hz ||
3749 spi->max_speed_hz > spi->controller->max_speed_hz))
3750 spi->max_speed_hz = spi->controller->max_speed_hz;
3751
3752 mutex_lock(&spi->controller->io_mutex);
3753
3754 if (spi->controller->setup) {
3755 status = spi->controller->setup(spi);
3756 if (status) {
3757 mutex_unlock(&spi->controller->io_mutex);
3758 dev_err(&spi->controller->dev, "Failed to setup device: %d\n",
3759 status);
3760 return status;
3761 }
3762 }
3763
3764 status = spi_set_cs_timing(spi);
3765 if (status) {
3766 mutex_unlock(&spi->controller->io_mutex);
3767 return status;
3768 }
3769
3770 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
3771 status = pm_runtime_resume_and_get(spi->controller->dev.parent);
3772 if (status < 0) {
3773 mutex_unlock(&spi->controller->io_mutex);
3774 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3775 status);
3776 return status;
3777 }
3778
3779 /*
3780 * We do not want to return positive value from pm_runtime_get,
3781 * there are many instances of devices calling spi_setup() and
3782 * checking for a non-zero return value instead of a negative
3783 * return value.
3784 */
3785 status = 0;
3786
3787 spi_set_cs(spi, false, true);
3788 pm_runtime_mark_last_busy(spi->controller->dev.parent);
3789 pm_runtime_put_autosuspend(spi->controller->dev.parent);
3790 } else {
3791 spi_set_cs(spi, false, true);
3792 }
3793
3794 mutex_unlock(&spi->controller->io_mutex);
3795
3796 if (spi->rt && !spi->controller->rt) {
3797 spi->controller->rt = true;
3798 spi_set_thread_rt(spi->controller);
3799 }
3800
3801 trace_spi_setup(spi, status);
3802
3803 dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3804 spi->mode & SPI_MODE_X_MASK,
3805 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
3806 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
3807 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
3808 (spi->mode & SPI_LOOP) ? "loopback, " : "",
3809 spi->bits_per_word, spi->max_speed_hz,
3810 status);
3811
3812 return status;
3813}
3814EXPORT_SYMBOL_GPL(spi_setup);
3815
3816static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
3817 struct spi_device *spi)
3818{
3819 int delay1, delay2;
3820
3821 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
3822 if (delay1 < 0)
3823 return delay1;
3824
3825 delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
3826 if (delay2 < 0)
3827 return delay2;
3828
3829 if (delay1 < delay2)
3830 memcpy(&xfer->word_delay, &spi->word_delay,
3831 sizeof(xfer->word_delay));
3832
3833 return 0;
3834}
3835
3836static int __spi_validate(struct spi_device *spi, struct spi_message *message)
3837{
3838 struct spi_controller *ctlr = spi->controller;
3839 struct spi_transfer *xfer;
3840 int w_size;
3841
3842 if (list_empty(&message->transfers))
3843 return -EINVAL;
3844
3845 /*
3846 * If an SPI controller does not support toggling the CS line on each
3847 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3848 * for the CS line, we can emulate the CS-per-word hardware function by
3849 * splitting transfers into one-word transfers and ensuring that
3850 * cs_change is set for each transfer.
3851 */
3852 if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
3853 spi->cs_gpiod)) {
3854 size_t maxsize;
3855 int ret;
3856
3857 maxsize = (spi->bits_per_word + 7) / 8;
3858
3859 /* spi_split_transfers_maxsize() requires message->spi */
3860 message->spi = spi;
3861
3862 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
3863 GFP_KERNEL);
3864 if (ret)
3865 return ret;
3866
3867 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3868 /* Don't change cs_change on the last entry in the list */
3869 if (list_is_last(&xfer->transfer_list, &message->transfers))
3870 break;
3871 xfer->cs_change = 1;
3872 }
3873 }
3874
3875 /*
3876 * Half-duplex links include original MicroWire, and ones with
3877 * only one data pin like SPI_3WIRE (switches direction) or where
3878 * either MOSI or MISO is missing. They can also be caused by
3879 * software limitations.
3880 */
3881 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
3882 (spi->mode & SPI_3WIRE)) {
3883 unsigned flags = ctlr->flags;
3884
3885 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3886 if (xfer->rx_buf && xfer->tx_buf)
3887 return -EINVAL;
3888 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
3889 return -EINVAL;
3890 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
3891 return -EINVAL;
3892 }
3893 }
3894
3895 /*
3896 * Set transfer bits_per_word and max speed as spi device default if
3897 * it is not set for this transfer.
3898 * Set transfer tx_nbits and rx_nbits as single transfer default
3899 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3900 * Ensure transfer word_delay is at least as long as that required by
3901 * device itself.
3902 */
3903 message->frame_length = 0;
3904 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3905 xfer->effective_speed_hz = 0;
3906 message->frame_length += xfer->len;
3907 if (!xfer->bits_per_word)
3908 xfer->bits_per_word = spi->bits_per_word;
3909
3910 if (!xfer->speed_hz)
3911 xfer->speed_hz = spi->max_speed_hz;
3912
3913 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
3914 xfer->speed_hz = ctlr->max_speed_hz;
3915
3916 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
3917 return -EINVAL;
3918
3919 /*
3920 * SPI transfer length should be multiple of SPI word size
3921 * where SPI word size should be power-of-two multiple.
3922 */
3923 if (xfer->bits_per_word <= 8)
3924 w_size = 1;
3925 else if (xfer->bits_per_word <= 16)
3926 w_size = 2;
3927 else
3928 w_size = 4;
3929
3930 /* No partial transfers accepted */
3931 if (xfer->len % w_size)
3932 return -EINVAL;
3933
3934 if (xfer->speed_hz && ctlr->min_speed_hz &&
3935 xfer->speed_hz < ctlr->min_speed_hz)
3936 return -EINVAL;
3937
3938 if (xfer->tx_buf && !xfer->tx_nbits)
3939 xfer->tx_nbits = SPI_NBITS_SINGLE;
3940 if (xfer->rx_buf && !xfer->rx_nbits)
3941 xfer->rx_nbits = SPI_NBITS_SINGLE;
3942 /*
3943 * Check transfer tx/rx_nbits:
3944 * 1. check the value matches one of single, dual and quad
3945 * 2. check tx/rx_nbits match the mode in spi_device
3946 */
3947 if (xfer->tx_buf) {
3948 if (spi->mode & SPI_NO_TX)
3949 return -EINVAL;
3950 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3951 xfer->tx_nbits != SPI_NBITS_DUAL &&
3952 xfer->tx_nbits != SPI_NBITS_QUAD)
3953 return -EINVAL;
3954 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3955 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3956 return -EINVAL;
3957 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3958 !(spi->mode & SPI_TX_QUAD))
3959 return -EINVAL;
3960 }
3961 /* Check transfer rx_nbits */
3962 if (xfer->rx_buf) {
3963 if (spi->mode & SPI_NO_RX)
3964 return -EINVAL;
3965 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3966 xfer->rx_nbits != SPI_NBITS_DUAL &&
3967 xfer->rx_nbits != SPI_NBITS_QUAD)
3968 return -EINVAL;
3969 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3970 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3971 return -EINVAL;
3972 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3973 !(spi->mode & SPI_RX_QUAD))
3974 return -EINVAL;
3975 }
3976
3977 if (_spi_xfer_word_delay_update(xfer, spi))
3978 return -EINVAL;
3979 }
3980
3981 message->status = -EINPROGRESS;
3982
3983 return 0;
3984}
3985
3986static int __spi_async(struct spi_device *spi, struct spi_message *message)
3987{
3988 struct spi_controller *ctlr = spi->controller;
3989 struct spi_transfer *xfer;
3990
3991 /*
3992 * Some controllers do not support doing regular SPI transfers. Return
3993 * ENOTSUPP when this is the case.
3994 */
3995 if (!ctlr->transfer)
3996 return -ENOTSUPP;
3997
3998 message->spi = spi;
3999
4000 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_async);
4001 SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_async);
4002
4003 trace_spi_message_submit(message);
4004
4005 if (!ctlr->ptp_sts_supported) {
4006 list_for_each_entry(xfer, &message->transfers, transfer_list) {
4007 xfer->ptp_sts_word_pre = 0;
4008 ptp_read_system_prets(xfer->ptp_sts);
4009 }
4010 }
4011
4012 return ctlr->transfer(spi, message);
4013}
4014
4015/**
4016 * spi_async - asynchronous SPI transfer
4017 * @spi: device with which data will be exchanged
4018 * @message: describes the data transfers, including completion callback
4019 * Context: any (irqs may be blocked, etc)
4020 *
4021 * This call may be used in_irq and other contexts which can't sleep,
4022 * as well as from task contexts which can sleep.
4023 *
4024 * The completion callback is invoked in a context which can't sleep.
4025 * Before that invocation, the value of message->status is undefined.
4026 * When the callback is issued, message->status holds either zero (to
4027 * indicate complete success) or a negative error code. After that
4028 * callback returns, the driver which issued the transfer request may
4029 * deallocate the associated memory; it's no longer in use by any SPI
4030 * core or controller driver code.
4031 *
4032 * Note that although all messages to a spi_device are handled in
4033 * FIFO order, messages may go to different devices in other orders.
4034 * Some device might be higher priority, or have various "hard" access
4035 * time requirements, for example.
4036 *
4037 * On detection of any fault during the transfer, processing of
4038 * the entire message is aborted, and the device is deselected.
4039 * Until returning from the associated message completion callback,
4040 * no other spi_message queued to that device will be processed.
4041 * (This rule applies equally to all the synchronous transfer calls,
4042 * which are wrappers around this core asynchronous primitive.)
4043 *
4044 * Return: zero on success, else a negative error code.
4045 */
4046int spi_async(struct spi_device *spi, struct spi_message *message)
4047{
4048 struct spi_controller *ctlr = spi->controller;
4049 int ret;
4050 unsigned long flags;
4051
4052 ret = __spi_validate(spi, message);
4053 if (ret != 0)
4054 return ret;
4055
4056 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
4057
4058 if (ctlr->bus_lock_flag)
4059 ret = -EBUSY;
4060 else
4061 ret = __spi_async(spi, message);
4062
4063 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
4064
4065 return ret;
4066}
4067EXPORT_SYMBOL_GPL(spi_async);
4068
4069/**
4070 * spi_async_locked - version of spi_async with exclusive bus usage
4071 * @spi: device with which data will be exchanged
4072 * @message: describes the data transfers, including completion callback
4073 * Context: any (irqs may be blocked, etc)
4074 *
4075 * This call may be used in_irq and other contexts which can't sleep,
4076 * as well as from task contexts which can sleep.
4077 *
4078 * The completion callback is invoked in a context which can't sleep.
4079 * Before that invocation, the value of message->status is undefined.
4080 * When the callback is issued, message->status holds either zero (to
4081 * indicate complete success) or a negative error code. After that
4082 * callback returns, the driver which issued the transfer request may
4083 * deallocate the associated memory; it's no longer in use by any SPI
4084 * core or controller driver code.
4085 *
4086 * Note that although all messages to a spi_device are handled in
4087 * FIFO order, messages may go to different devices in other orders.
4088 * Some device might be higher priority, or have various "hard" access
4089 * time requirements, for example.
4090 *
4091 * On detection of any fault during the transfer, processing of
4092 * the entire message is aborted, and the device is deselected.
4093 * Until returning from the associated message completion callback,
4094 * no other spi_message queued to that device will be processed.
4095 * (This rule applies equally to all the synchronous transfer calls,
4096 * which are wrappers around this core asynchronous primitive.)
4097 *
4098 * Return: zero on success, else a negative error code.
4099 */
4100static int spi_async_locked(struct spi_device *spi, struct spi_message *message)
4101{
4102 struct spi_controller *ctlr = spi->controller;
4103 int ret;
4104 unsigned long flags;
4105
4106 ret = __spi_validate(spi, message);
4107 if (ret != 0)
4108 return ret;
4109
4110 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
4111
4112 ret = __spi_async(spi, message);
4113
4114 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
4115
4116 return ret;
4117
4118}
4119
4120static void __spi_transfer_message_noqueue(struct spi_controller *ctlr, struct spi_message *msg)
4121{
4122 bool was_busy;
4123 int ret;
4124
4125 mutex_lock(&ctlr->io_mutex);
4126
4127 was_busy = ctlr->busy;
4128
4129 ctlr->cur_msg = msg;
4130 ret = __spi_pump_transfer_message(ctlr, msg, was_busy);
4131 if (ret)
4132 goto out;
4133
4134 ctlr->cur_msg = NULL;
4135 ctlr->fallback = false;
4136
4137 if (!was_busy) {
4138 kfree(ctlr->dummy_rx);
4139 ctlr->dummy_rx = NULL;
4140 kfree(ctlr->dummy_tx);
4141 ctlr->dummy_tx = NULL;
4142 if (ctlr->unprepare_transfer_hardware &&
4143 ctlr->unprepare_transfer_hardware(ctlr))
4144 dev_err(&ctlr->dev,
4145 "failed to unprepare transfer hardware\n");
4146 spi_idle_runtime_pm(ctlr);
4147 }
4148
4149out:
4150 mutex_unlock(&ctlr->io_mutex);
4151}
4152
4153/*-------------------------------------------------------------------------*/
4154
4155/*
4156 * Utility methods for SPI protocol drivers, layered on
4157 * top of the core. Some other utility methods are defined as
4158 * inline functions.
4159 */
4160
4161static void spi_complete(void *arg)
4162{
4163 complete(arg);
4164}
4165
4166static int __spi_sync(struct spi_device *spi, struct spi_message *message)
4167{
4168 DECLARE_COMPLETION_ONSTACK(done);
4169 int status;
4170 struct spi_controller *ctlr = spi->controller;
4171
4172 status = __spi_validate(spi, message);
4173 if (status != 0)
4174 return status;
4175
4176 message->spi = spi;
4177
4178 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync);
4179 SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync);
4180
4181 /*
4182 * Checking queue_empty here only guarantees async/sync message
4183 * ordering when coming from the same context. It does not need to
4184 * guard against reentrancy from a different context. The io_mutex
4185 * will catch those cases.
4186 */
4187 if (READ_ONCE(ctlr->queue_empty) && !ctlr->must_async) {
4188 message->actual_length = 0;
4189 message->status = -EINPROGRESS;
4190
4191 trace_spi_message_submit(message);
4192
4193 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync_immediate);
4194 SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync_immediate);
4195
4196 __spi_transfer_message_noqueue(ctlr, message);
4197
4198 return message->status;
4199 }
4200
4201 /*
4202 * There are messages in the async queue that could have originated
4203 * from the same context, so we need to preserve ordering.
4204 * Therefor we send the message to the async queue and wait until they
4205 * are completed.
4206 */
4207 message->complete = spi_complete;
4208 message->context = &done;
4209 status = spi_async_locked(spi, message);
4210 if (status == 0) {
4211 wait_for_completion(&done);
4212 status = message->status;
4213 }
4214 message->context = NULL;
4215
4216 return status;
4217}
4218
4219/**
4220 * spi_sync - blocking/synchronous SPI data transfers
4221 * @spi: device with which data will be exchanged
4222 * @message: describes the data transfers
4223 * Context: can sleep
4224 *
4225 * This call may only be used from a context that may sleep. The sleep
4226 * is non-interruptible, and has no timeout. Low-overhead controller
4227 * drivers may DMA directly into and out of the message buffers.
4228 *
4229 * Note that the SPI device's chip select is active during the message,
4230 * and then is normally disabled between messages. Drivers for some
4231 * frequently-used devices may want to minimize costs of selecting a chip,
4232 * by leaving it selected in anticipation that the next message will go
4233 * to the same chip. (That may increase power usage.)
4234 *
4235 * Also, the caller is guaranteeing that the memory associated with the
4236 * message will not be freed before this call returns.
4237 *
4238 * Return: zero on success, else a negative error code.
4239 */
4240int spi_sync(struct spi_device *spi, struct spi_message *message)
4241{
4242 int ret;
4243
4244 mutex_lock(&spi->controller->bus_lock_mutex);
4245 ret = __spi_sync(spi, message);
4246 mutex_unlock(&spi->controller->bus_lock_mutex);
4247
4248 return ret;
4249}
4250EXPORT_SYMBOL_GPL(spi_sync);
4251
4252/**
4253 * spi_sync_locked - version of spi_sync with exclusive bus usage
4254 * @spi: device with which data will be exchanged
4255 * @message: describes the data transfers
4256 * Context: can sleep
4257 *
4258 * This call may only be used from a context that may sleep. The sleep
4259 * is non-interruptible, and has no timeout. Low-overhead controller
4260 * drivers may DMA directly into and out of the message buffers.
4261 *
4262 * This call should be used by drivers that require exclusive access to the
4263 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
4264 * be released by a spi_bus_unlock call when the exclusive access is over.
4265 *
4266 * Return: zero on success, else a negative error code.
4267 */
4268int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
4269{
4270 return __spi_sync(spi, message);
4271}
4272EXPORT_SYMBOL_GPL(spi_sync_locked);
4273
4274/**
4275 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
4276 * @ctlr: SPI bus master that should be locked for exclusive bus access
4277 * Context: can sleep
4278 *
4279 * This call may only be used from a context that may sleep. The sleep
4280 * is non-interruptible, and has no timeout.
4281 *
4282 * This call should be used by drivers that require exclusive access to the
4283 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
4284 * exclusive access is over. Data transfer must be done by spi_sync_locked
4285 * and spi_async_locked calls when the SPI bus lock is held.
4286 *
4287 * Return: always zero.
4288 */
4289int spi_bus_lock(struct spi_controller *ctlr)
4290{
4291 unsigned long flags;
4292
4293 mutex_lock(&ctlr->bus_lock_mutex);
4294
4295 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
4296 ctlr->bus_lock_flag = 1;
4297 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
4298
4299 /* Mutex remains locked until spi_bus_unlock() is called */
4300
4301 return 0;
4302}
4303EXPORT_SYMBOL_GPL(spi_bus_lock);
4304
4305/**
4306 * spi_bus_unlock - release the lock for exclusive SPI bus usage
4307 * @ctlr: SPI bus master that was locked for exclusive bus access
4308 * Context: can sleep
4309 *
4310 * This call may only be used from a context that may sleep. The sleep
4311 * is non-interruptible, and has no timeout.
4312 *
4313 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
4314 * call.
4315 *
4316 * Return: always zero.
4317 */
4318int spi_bus_unlock(struct spi_controller *ctlr)
4319{
4320 ctlr->bus_lock_flag = 0;
4321
4322 mutex_unlock(&ctlr->bus_lock_mutex);
4323
4324 return 0;
4325}
4326EXPORT_SYMBOL_GPL(spi_bus_unlock);
4327
4328/* Portable code must never pass more than 32 bytes */
4329#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
4330
4331static u8 *buf;
4332
4333/**
4334 * spi_write_then_read - SPI synchronous write followed by read
4335 * @spi: device with which data will be exchanged
4336 * @txbuf: data to be written (need not be dma-safe)
4337 * @n_tx: size of txbuf, in bytes
4338 * @rxbuf: buffer into which data will be read (need not be dma-safe)
4339 * @n_rx: size of rxbuf, in bytes
4340 * Context: can sleep
4341 *
4342 * This performs a half duplex MicroWire style transaction with the
4343 * device, sending txbuf and then reading rxbuf. The return value
4344 * is zero for success, else a negative errno status code.
4345 * This call may only be used from a context that may sleep.
4346 *
4347 * Parameters to this routine are always copied using a small buffer.
4348 * Performance-sensitive or bulk transfer code should instead use
4349 * spi_{async,sync}() calls with dma-safe buffers.
4350 *
4351 * Return: zero on success, else a negative error code.
4352 */
4353int spi_write_then_read(struct spi_device *spi,
4354 const void *txbuf, unsigned n_tx,
4355 void *rxbuf, unsigned n_rx)
4356{
4357 static DEFINE_MUTEX(lock);
4358
4359 int status;
4360 struct spi_message message;
4361 struct spi_transfer x[2];
4362 u8 *local_buf;
4363
4364 /*
4365 * Use preallocated DMA-safe buffer if we can. We can't avoid
4366 * copying here, (as a pure convenience thing), but we can
4367 * keep heap costs out of the hot path unless someone else is
4368 * using the pre-allocated buffer or the transfer is too large.
4369 */
4370 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
4371 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
4372 GFP_KERNEL | GFP_DMA);
4373 if (!local_buf)
4374 return -ENOMEM;
4375 } else {
4376 local_buf = buf;
4377 }
4378
4379 spi_message_init(&message);
4380 memset(x, 0, sizeof(x));
4381 if (n_tx) {
4382 x[0].len = n_tx;
4383 spi_message_add_tail(&x[0], &message);
4384 }
4385 if (n_rx) {
4386 x[1].len = n_rx;
4387 spi_message_add_tail(&x[1], &message);
4388 }
4389
4390 memcpy(local_buf, txbuf, n_tx);
4391 x[0].tx_buf = local_buf;
4392 x[1].rx_buf = local_buf + n_tx;
4393
4394 /* Do the i/o */
4395 status = spi_sync(spi, &message);
4396 if (status == 0)
4397 memcpy(rxbuf, x[1].rx_buf, n_rx);
4398
4399 if (x[0].tx_buf == buf)
4400 mutex_unlock(&lock);
4401 else
4402 kfree(local_buf);
4403
4404 return status;
4405}
4406EXPORT_SYMBOL_GPL(spi_write_then_read);
4407
4408/*-------------------------------------------------------------------------*/
4409
4410#if IS_ENABLED(CONFIG_OF_DYNAMIC)
4411/* Must call put_device() when done with returned spi_device device */
4412static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
4413{
4414 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
4415
4416 return dev ? to_spi_device(dev) : NULL;
4417}
4418
4419/* The spi controllers are not using spi_bus, so we find it with another way */
4420static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
4421{
4422 struct device *dev;
4423
4424 dev = class_find_device_by_of_node(&spi_master_class, node);
4425 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4426 dev = class_find_device_by_of_node(&spi_slave_class, node);
4427 if (!dev)
4428 return NULL;
4429
4430 /* Reference got in class_find_device */
4431 return container_of(dev, struct spi_controller, dev);
4432}
4433
4434static int of_spi_notify(struct notifier_block *nb, unsigned long action,
4435 void *arg)
4436{
4437 struct of_reconfig_data *rd = arg;
4438 struct spi_controller *ctlr;
4439 struct spi_device *spi;
4440
4441 switch (of_reconfig_get_state_change(action, arg)) {
4442 case OF_RECONFIG_CHANGE_ADD:
4443 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
4444 if (ctlr == NULL)
4445 return NOTIFY_OK; /* Not for us */
4446
4447 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
4448 put_device(&ctlr->dev);
4449 return NOTIFY_OK;
4450 }
4451
4452 spi = of_register_spi_device(ctlr, rd->dn);
4453 put_device(&ctlr->dev);
4454
4455 if (IS_ERR(spi)) {
4456 pr_err("%s: failed to create for '%pOF'\n",
4457 __func__, rd->dn);
4458 of_node_clear_flag(rd->dn, OF_POPULATED);
4459 return notifier_from_errno(PTR_ERR(spi));
4460 }
4461 break;
4462
4463 case OF_RECONFIG_CHANGE_REMOVE:
4464 /* Already depopulated? */
4465 if (!of_node_check_flag(rd->dn, OF_POPULATED))
4466 return NOTIFY_OK;
4467
4468 /* Find our device by node */
4469 spi = of_find_spi_device_by_node(rd->dn);
4470 if (spi == NULL)
4471 return NOTIFY_OK; /* No? not meant for us */
4472
4473 /* Unregister takes one ref away */
4474 spi_unregister_device(spi);
4475
4476 /* And put the reference of the find */
4477 put_device(&spi->dev);
4478 break;
4479 }
4480
4481 return NOTIFY_OK;
4482}
4483
4484static struct notifier_block spi_of_notifier = {
4485 .notifier_call = of_spi_notify,
4486};
4487#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4488extern struct notifier_block spi_of_notifier;
4489#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4490
4491#if IS_ENABLED(CONFIG_ACPI)
4492static int spi_acpi_controller_match(struct device *dev, const void *data)
4493{
4494 return ACPI_COMPANION(dev->parent) == data;
4495}
4496
4497static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4498{
4499 struct device *dev;
4500
4501 dev = class_find_device(&spi_master_class, NULL, adev,
4502 spi_acpi_controller_match);
4503 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4504 dev = class_find_device(&spi_slave_class, NULL, adev,
4505 spi_acpi_controller_match);
4506 if (!dev)
4507 return NULL;
4508
4509 return container_of(dev, struct spi_controller, dev);
4510}
4511
4512static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4513{
4514 struct device *dev;
4515
4516 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4517 return to_spi_device(dev);
4518}
4519
4520static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4521 void *arg)
4522{
4523 struct acpi_device *adev = arg;
4524 struct spi_controller *ctlr;
4525 struct spi_device *spi;
4526
4527 switch (value) {
4528 case ACPI_RECONFIG_DEVICE_ADD:
4529 ctlr = acpi_spi_find_controller_by_adev(acpi_dev_parent(adev));
4530 if (!ctlr)
4531 break;
4532
4533 acpi_register_spi_device(ctlr, adev);
4534 put_device(&ctlr->dev);
4535 break;
4536 case ACPI_RECONFIG_DEVICE_REMOVE:
4537 if (!acpi_device_enumerated(adev))
4538 break;
4539
4540 spi = acpi_spi_find_device_by_adev(adev);
4541 if (!spi)
4542 break;
4543
4544 spi_unregister_device(spi);
4545 put_device(&spi->dev);
4546 break;
4547 }
4548
4549 return NOTIFY_OK;
4550}
4551
4552static struct notifier_block spi_acpi_notifier = {
4553 .notifier_call = acpi_spi_notify,
4554};
4555#else
4556extern struct notifier_block spi_acpi_notifier;
4557#endif
4558
4559static int __init spi_init(void)
4560{
4561 int status;
4562
4563 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4564 if (!buf) {
4565 status = -ENOMEM;
4566 goto err0;
4567 }
4568
4569 status = bus_register(&spi_bus_type);
4570 if (status < 0)
4571 goto err1;
4572
4573 status = class_register(&spi_master_class);
4574 if (status < 0)
4575 goto err2;
4576
4577 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4578 status = class_register(&spi_slave_class);
4579 if (status < 0)
4580 goto err3;
4581 }
4582
4583 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4584 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4585 if (IS_ENABLED(CONFIG_ACPI))
4586 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4587
4588 return 0;
4589
4590err3:
4591 class_unregister(&spi_master_class);
4592err2:
4593 bus_unregister(&spi_bus_type);
4594err1:
4595 kfree(buf);
4596 buf = NULL;
4597err0:
4598 return status;
4599}
4600
4601/*
4602 * A board_info is normally registered in arch_initcall(),
4603 * but even essential drivers wait till later.
4604 *
4605 * REVISIT only boardinfo really needs static linking. The rest (device and
4606 * driver registration) _could_ be dynamically linked (modular) ... Costs
4607 * include needing to have boardinfo data structures be much more public.
4608 */
4609postcore_initcall(spi_init);
1/*
2 * SPI init/core code
3 *
4 * Copyright (C) 2005 David Brownell
5 * Copyright (C) 2008 Secret Lab Technologies Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18#include <linux/kernel.h>
19#include <linux/device.h>
20#include <linux/init.h>
21#include <linux/cache.h>
22#include <linux/dma-mapping.h>
23#include <linux/dmaengine.h>
24#include <linux/mutex.h>
25#include <linux/of_device.h>
26#include <linux/of_irq.h>
27#include <linux/clk/clk-conf.h>
28#include <linux/slab.h>
29#include <linux/mod_devicetable.h>
30#include <linux/spi/spi.h>
31#include <linux/of_gpio.h>
32#include <linux/pm_runtime.h>
33#include <linux/pm_domain.h>
34#include <linux/export.h>
35#include <linux/sched/rt.h>
36#include <linux/delay.h>
37#include <linux/kthread.h>
38#include <linux/ioport.h>
39#include <linux/acpi.h>
40
41#define CREATE_TRACE_POINTS
42#include <trace/events/spi.h>
43
44static void spidev_release(struct device *dev)
45{
46 struct spi_device *spi = to_spi_device(dev);
47
48 /* spi masters may cleanup for released devices */
49 if (spi->master->cleanup)
50 spi->master->cleanup(spi);
51
52 spi_master_put(spi->master);
53 kfree(spi);
54}
55
56static ssize_t
57modalias_show(struct device *dev, struct device_attribute *a, char *buf)
58{
59 const struct spi_device *spi = to_spi_device(dev);
60 int len;
61
62 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
63 if (len != -ENODEV)
64 return len;
65
66 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
67}
68static DEVICE_ATTR_RO(modalias);
69
70#define SPI_STATISTICS_ATTRS(field, file) \
71static ssize_t spi_master_##field##_show(struct device *dev, \
72 struct device_attribute *attr, \
73 char *buf) \
74{ \
75 struct spi_master *master = container_of(dev, \
76 struct spi_master, dev); \
77 return spi_statistics_##field##_show(&master->statistics, buf); \
78} \
79static struct device_attribute dev_attr_spi_master_##field = { \
80 .attr = { .name = file, .mode = S_IRUGO }, \
81 .show = spi_master_##field##_show, \
82}; \
83static ssize_t spi_device_##field##_show(struct device *dev, \
84 struct device_attribute *attr, \
85 char *buf) \
86{ \
87 struct spi_device *spi = to_spi_device(dev); \
88 return spi_statistics_##field##_show(&spi->statistics, buf); \
89} \
90static struct device_attribute dev_attr_spi_device_##field = { \
91 .attr = { .name = file, .mode = S_IRUGO }, \
92 .show = spi_device_##field##_show, \
93}
94
95#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
96static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
97 char *buf) \
98{ \
99 unsigned long flags; \
100 ssize_t len; \
101 spin_lock_irqsave(&stat->lock, flags); \
102 len = sprintf(buf, format_string, stat->field); \
103 spin_unlock_irqrestore(&stat->lock, flags); \
104 return len; \
105} \
106SPI_STATISTICS_ATTRS(name, file)
107
108#define SPI_STATISTICS_SHOW(field, format_string) \
109 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
110 field, format_string)
111
112SPI_STATISTICS_SHOW(messages, "%lu");
113SPI_STATISTICS_SHOW(transfers, "%lu");
114SPI_STATISTICS_SHOW(errors, "%lu");
115SPI_STATISTICS_SHOW(timedout, "%lu");
116
117SPI_STATISTICS_SHOW(spi_sync, "%lu");
118SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
119SPI_STATISTICS_SHOW(spi_async, "%lu");
120
121SPI_STATISTICS_SHOW(bytes, "%llu");
122SPI_STATISTICS_SHOW(bytes_rx, "%llu");
123SPI_STATISTICS_SHOW(bytes_tx, "%llu");
124
125#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
126 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
127 "transfer_bytes_histo_" number, \
128 transfer_bytes_histo[index], "%lu")
129SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
130SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
131SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
132SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
133SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
134SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
135SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
136SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
137SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
138SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
139SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
140SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
141SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
142SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
143SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
144SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
145SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
146
147SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
148
149static struct attribute *spi_dev_attrs[] = {
150 &dev_attr_modalias.attr,
151 NULL,
152};
153
154static const struct attribute_group spi_dev_group = {
155 .attrs = spi_dev_attrs,
156};
157
158static struct attribute *spi_device_statistics_attrs[] = {
159 &dev_attr_spi_device_messages.attr,
160 &dev_attr_spi_device_transfers.attr,
161 &dev_attr_spi_device_errors.attr,
162 &dev_attr_spi_device_timedout.attr,
163 &dev_attr_spi_device_spi_sync.attr,
164 &dev_attr_spi_device_spi_sync_immediate.attr,
165 &dev_attr_spi_device_spi_async.attr,
166 &dev_attr_spi_device_bytes.attr,
167 &dev_attr_spi_device_bytes_rx.attr,
168 &dev_attr_spi_device_bytes_tx.attr,
169 &dev_attr_spi_device_transfer_bytes_histo0.attr,
170 &dev_attr_spi_device_transfer_bytes_histo1.attr,
171 &dev_attr_spi_device_transfer_bytes_histo2.attr,
172 &dev_attr_spi_device_transfer_bytes_histo3.attr,
173 &dev_attr_spi_device_transfer_bytes_histo4.attr,
174 &dev_attr_spi_device_transfer_bytes_histo5.attr,
175 &dev_attr_spi_device_transfer_bytes_histo6.attr,
176 &dev_attr_spi_device_transfer_bytes_histo7.attr,
177 &dev_attr_spi_device_transfer_bytes_histo8.attr,
178 &dev_attr_spi_device_transfer_bytes_histo9.attr,
179 &dev_attr_spi_device_transfer_bytes_histo10.attr,
180 &dev_attr_spi_device_transfer_bytes_histo11.attr,
181 &dev_attr_spi_device_transfer_bytes_histo12.attr,
182 &dev_attr_spi_device_transfer_bytes_histo13.attr,
183 &dev_attr_spi_device_transfer_bytes_histo14.attr,
184 &dev_attr_spi_device_transfer_bytes_histo15.attr,
185 &dev_attr_spi_device_transfer_bytes_histo16.attr,
186 &dev_attr_spi_device_transfers_split_maxsize.attr,
187 NULL,
188};
189
190static const struct attribute_group spi_device_statistics_group = {
191 .name = "statistics",
192 .attrs = spi_device_statistics_attrs,
193};
194
195static const struct attribute_group *spi_dev_groups[] = {
196 &spi_dev_group,
197 &spi_device_statistics_group,
198 NULL,
199};
200
201static struct attribute *spi_master_statistics_attrs[] = {
202 &dev_attr_spi_master_messages.attr,
203 &dev_attr_spi_master_transfers.attr,
204 &dev_attr_spi_master_errors.attr,
205 &dev_attr_spi_master_timedout.attr,
206 &dev_attr_spi_master_spi_sync.attr,
207 &dev_attr_spi_master_spi_sync_immediate.attr,
208 &dev_attr_spi_master_spi_async.attr,
209 &dev_attr_spi_master_bytes.attr,
210 &dev_attr_spi_master_bytes_rx.attr,
211 &dev_attr_spi_master_bytes_tx.attr,
212 &dev_attr_spi_master_transfer_bytes_histo0.attr,
213 &dev_attr_spi_master_transfer_bytes_histo1.attr,
214 &dev_attr_spi_master_transfer_bytes_histo2.attr,
215 &dev_attr_spi_master_transfer_bytes_histo3.attr,
216 &dev_attr_spi_master_transfer_bytes_histo4.attr,
217 &dev_attr_spi_master_transfer_bytes_histo5.attr,
218 &dev_attr_spi_master_transfer_bytes_histo6.attr,
219 &dev_attr_spi_master_transfer_bytes_histo7.attr,
220 &dev_attr_spi_master_transfer_bytes_histo8.attr,
221 &dev_attr_spi_master_transfer_bytes_histo9.attr,
222 &dev_attr_spi_master_transfer_bytes_histo10.attr,
223 &dev_attr_spi_master_transfer_bytes_histo11.attr,
224 &dev_attr_spi_master_transfer_bytes_histo12.attr,
225 &dev_attr_spi_master_transfer_bytes_histo13.attr,
226 &dev_attr_spi_master_transfer_bytes_histo14.attr,
227 &dev_attr_spi_master_transfer_bytes_histo15.attr,
228 &dev_attr_spi_master_transfer_bytes_histo16.attr,
229 &dev_attr_spi_master_transfers_split_maxsize.attr,
230 NULL,
231};
232
233static const struct attribute_group spi_master_statistics_group = {
234 .name = "statistics",
235 .attrs = spi_master_statistics_attrs,
236};
237
238static const struct attribute_group *spi_master_groups[] = {
239 &spi_master_statistics_group,
240 NULL,
241};
242
243void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
244 struct spi_transfer *xfer,
245 struct spi_master *master)
246{
247 unsigned long flags;
248 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
249
250 if (l2len < 0)
251 l2len = 0;
252
253 spin_lock_irqsave(&stats->lock, flags);
254
255 stats->transfers++;
256 stats->transfer_bytes_histo[l2len]++;
257
258 stats->bytes += xfer->len;
259 if ((xfer->tx_buf) &&
260 (xfer->tx_buf != master->dummy_tx))
261 stats->bytes_tx += xfer->len;
262 if ((xfer->rx_buf) &&
263 (xfer->rx_buf != master->dummy_rx))
264 stats->bytes_rx += xfer->len;
265
266 spin_unlock_irqrestore(&stats->lock, flags);
267}
268EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
269
270/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
271 * and the sysfs version makes coldplug work too.
272 */
273
274static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
275 const struct spi_device *sdev)
276{
277 while (id->name[0]) {
278 if (!strcmp(sdev->modalias, id->name))
279 return id;
280 id++;
281 }
282 return NULL;
283}
284
285const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
286{
287 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
288
289 return spi_match_id(sdrv->id_table, sdev);
290}
291EXPORT_SYMBOL_GPL(spi_get_device_id);
292
293static int spi_match_device(struct device *dev, struct device_driver *drv)
294{
295 const struct spi_device *spi = to_spi_device(dev);
296 const struct spi_driver *sdrv = to_spi_driver(drv);
297
298 /* Attempt an OF style match */
299 if (of_driver_match_device(dev, drv))
300 return 1;
301
302 /* Then try ACPI */
303 if (acpi_driver_match_device(dev, drv))
304 return 1;
305
306 if (sdrv->id_table)
307 return !!spi_match_id(sdrv->id_table, spi);
308
309 return strcmp(spi->modalias, drv->name) == 0;
310}
311
312static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
313{
314 const struct spi_device *spi = to_spi_device(dev);
315 int rc;
316
317 rc = acpi_device_uevent_modalias(dev, env);
318 if (rc != -ENODEV)
319 return rc;
320
321 add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
322 return 0;
323}
324
325struct bus_type spi_bus_type = {
326 .name = "spi",
327 .dev_groups = spi_dev_groups,
328 .match = spi_match_device,
329 .uevent = spi_uevent,
330};
331EXPORT_SYMBOL_GPL(spi_bus_type);
332
333
334static int spi_drv_probe(struct device *dev)
335{
336 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
337 struct spi_device *spi = to_spi_device(dev);
338 int ret;
339
340 ret = of_clk_set_defaults(dev->of_node, false);
341 if (ret)
342 return ret;
343
344 if (dev->of_node) {
345 spi->irq = of_irq_get(dev->of_node, 0);
346 if (spi->irq == -EPROBE_DEFER)
347 return -EPROBE_DEFER;
348 if (spi->irq < 0)
349 spi->irq = 0;
350 }
351
352 ret = dev_pm_domain_attach(dev, true);
353 if (ret != -EPROBE_DEFER) {
354 ret = sdrv->probe(spi);
355 if (ret)
356 dev_pm_domain_detach(dev, true);
357 }
358
359 return ret;
360}
361
362static int spi_drv_remove(struct device *dev)
363{
364 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
365 int ret;
366
367 ret = sdrv->remove(to_spi_device(dev));
368 dev_pm_domain_detach(dev, true);
369
370 return ret;
371}
372
373static void spi_drv_shutdown(struct device *dev)
374{
375 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
376
377 sdrv->shutdown(to_spi_device(dev));
378}
379
380/**
381 * __spi_register_driver - register a SPI driver
382 * @owner: owner module of the driver to register
383 * @sdrv: the driver to register
384 * Context: can sleep
385 *
386 * Return: zero on success, else a negative error code.
387 */
388int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
389{
390 sdrv->driver.owner = owner;
391 sdrv->driver.bus = &spi_bus_type;
392 if (sdrv->probe)
393 sdrv->driver.probe = spi_drv_probe;
394 if (sdrv->remove)
395 sdrv->driver.remove = spi_drv_remove;
396 if (sdrv->shutdown)
397 sdrv->driver.shutdown = spi_drv_shutdown;
398 return driver_register(&sdrv->driver);
399}
400EXPORT_SYMBOL_GPL(__spi_register_driver);
401
402/*-------------------------------------------------------------------------*/
403
404/* SPI devices should normally not be created by SPI device drivers; that
405 * would make them board-specific. Similarly with SPI master drivers.
406 * Device registration normally goes into like arch/.../mach.../board-YYY.c
407 * with other readonly (flashable) information about mainboard devices.
408 */
409
410struct boardinfo {
411 struct list_head list;
412 struct spi_board_info board_info;
413};
414
415static LIST_HEAD(board_list);
416static LIST_HEAD(spi_master_list);
417
418/*
419 * Used to protect add/del opertion for board_info list and
420 * spi_master list, and their matching process
421 */
422static DEFINE_MUTEX(board_lock);
423
424/**
425 * spi_alloc_device - Allocate a new SPI device
426 * @master: Controller to which device is connected
427 * Context: can sleep
428 *
429 * Allows a driver to allocate and initialize a spi_device without
430 * registering it immediately. This allows a driver to directly
431 * fill the spi_device with device parameters before calling
432 * spi_add_device() on it.
433 *
434 * Caller is responsible to call spi_add_device() on the returned
435 * spi_device structure to add it to the SPI master. If the caller
436 * needs to discard the spi_device without adding it, then it should
437 * call spi_dev_put() on it.
438 *
439 * Return: a pointer to the new device, or NULL.
440 */
441struct spi_device *spi_alloc_device(struct spi_master *master)
442{
443 struct spi_device *spi;
444
445 if (!spi_master_get(master))
446 return NULL;
447
448 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
449 if (!spi) {
450 spi_master_put(master);
451 return NULL;
452 }
453
454 spi->master = master;
455 spi->dev.parent = &master->dev;
456 spi->dev.bus = &spi_bus_type;
457 spi->dev.release = spidev_release;
458 spi->cs_gpio = -ENOENT;
459
460 spin_lock_init(&spi->statistics.lock);
461
462 device_initialize(&spi->dev);
463 return spi;
464}
465EXPORT_SYMBOL_GPL(spi_alloc_device);
466
467static void spi_dev_set_name(struct spi_device *spi)
468{
469 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
470
471 if (adev) {
472 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
473 return;
474 }
475
476 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
477 spi->chip_select);
478}
479
480static int spi_dev_check(struct device *dev, void *data)
481{
482 struct spi_device *spi = to_spi_device(dev);
483 struct spi_device *new_spi = data;
484
485 if (spi->master == new_spi->master &&
486 spi->chip_select == new_spi->chip_select)
487 return -EBUSY;
488 return 0;
489}
490
491/**
492 * spi_add_device - Add spi_device allocated with spi_alloc_device
493 * @spi: spi_device to register
494 *
495 * Companion function to spi_alloc_device. Devices allocated with
496 * spi_alloc_device can be added onto the spi bus with this function.
497 *
498 * Return: 0 on success; negative errno on failure
499 */
500int spi_add_device(struct spi_device *spi)
501{
502 static DEFINE_MUTEX(spi_add_lock);
503 struct spi_master *master = spi->master;
504 struct device *dev = master->dev.parent;
505 int status;
506
507 /* Chipselects are numbered 0..max; validate. */
508 if (spi->chip_select >= master->num_chipselect) {
509 dev_err(dev, "cs%d >= max %d\n",
510 spi->chip_select,
511 master->num_chipselect);
512 return -EINVAL;
513 }
514
515 /* Set the bus ID string */
516 spi_dev_set_name(spi);
517
518 /* We need to make sure there's no other device with this
519 * chipselect **BEFORE** we call setup(), else we'll trash
520 * its configuration. Lock against concurrent add() calls.
521 */
522 mutex_lock(&spi_add_lock);
523
524 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
525 if (status) {
526 dev_err(dev, "chipselect %d already in use\n",
527 spi->chip_select);
528 goto done;
529 }
530
531 if (master->cs_gpios)
532 spi->cs_gpio = master->cs_gpios[spi->chip_select];
533
534 /* Drivers may modify this initial i/o setup, but will
535 * normally rely on the device being setup. Devices
536 * using SPI_CS_HIGH can't coexist well otherwise...
537 */
538 status = spi_setup(spi);
539 if (status < 0) {
540 dev_err(dev, "can't setup %s, status %d\n",
541 dev_name(&spi->dev), status);
542 goto done;
543 }
544
545 /* Device may be bound to an active driver when this returns */
546 status = device_add(&spi->dev);
547 if (status < 0)
548 dev_err(dev, "can't add %s, status %d\n",
549 dev_name(&spi->dev), status);
550 else
551 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
552
553done:
554 mutex_unlock(&spi_add_lock);
555 return status;
556}
557EXPORT_SYMBOL_GPL(spi_add_device);
558
559/**
560 * spi_new_device - instantiate one new SPI device
561 * @master: Controller to which device is connected
562 * @chip: Describes the SPI device
563 * Context: can sleep
564 *
565 * On typical mainboards, this is purely internal; and it's not needed
566 * after board init creates the hard-wired devices. Some development
567 * platforms may not be able to use spi_register_board_info though, and
568 * this is exported so that for example a USB or parport based adapter
569 * driver could add devices (which it would learn about out-of-band).
570 *
571 * Return: the new device, or NULL.
572 */
573struct spi_device *spi_new_device(struct spi_master *master,
574 struct spi_board_info *chip)
575{
576 struct spi_device *proxy;
577 int status;
578
579 /* NOTE: caller did any chip->bus_num checks necessary.
580 *
581 * Also, unless we change the return value convention to use
582 * error-or-pointer (not NULL-or-pointer), troubleshootability
583 * suggests syslogged diagnostics are best here (ugh).
584 */
585
586 proxy = spi_alloc_device(master);
587 if (!proxy)
588 return NULL;
589
590 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
591
592 proxy->chip_select = chip->chip_select;
593 proxy->max_speed_hz = chip->max_speed_hz;
594 proxy->mode = chip->mode;
595 proxy->irq = chip->irq;
596 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
597 proxy->dev.platform_data = (void *) chip->platform_data;
598 proxy->controller_data = chip->controller_data;
599 proxy->controller_state = NULL;
600
601 status = spi_add_device(proxy);
602 if (status < 0) {
603 spi_dev_put(proxy);
604 return NULL;
605 }
606
607 return proxy;
608}
609EXPORT_SYMBOL_GPL(spi_new_device);
610
611/**
612 * spi_unregister_device - unregister a single SPI device
613 * @spi: spi_device to unregister
614 *
615 * Start making the passed SPI device vanish. Normally this would be handled
616 * by spi_unregister_master().
617 */
618void spi_unregister_device(struct spi_device *spi)
619{
620 if (!spi)
621 return;
622
623 if (spi->dev.of_node)
624 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
625 device_unregister(&spi->dev);
626}
627EXPORT_SYMBOL_GPL(spi_unregister_device);
628
629static void spi_match_master_to_boardinfo(struct spi_master *master,
630 struct spi_board_info *bi)
631{
632 struct spi_device *dev;
633
634 if (master->bus_num != bi->bus_num)
635 return;
636
637 dev = spi_new_device(master, bi);
638 if (!dev)
639 dev_err(master->dev.parent, "can't create new device for %s\n",
640 bi->modalias);
641}
642
643/**
644 * spi_register_board_info - register SPI devices for a given board
645 * @info: array of chip descriptors
646 * @n: how many descriptors are provided
647 * Context: can sleep
648 *
649 * Board-specific early init code calls this (probably during arch_initcall)
650 * with segments of the SPI device table. Any device nodes are created later,
651 * after the relevant parent SPI controller (bus_num) is defined. We keep
652 * this table of devices forever, so that reloading a controller driver will
653 * not make Linux forget about these hard-wired devices.
654 *
655 * Other code can also call this, e.g. a particular add-on board might provide
656 * SPI devices through its expansion connector, so code initializing that board
657 * would naturally declare its SPI devices.
658 *
659 * The board info passed can safely be __initdata ... but be careful of
660 * any embedded pointers (platform_data, etc), they're copied as-is.
661 *
662 * Return: zero on success, else a negative error code.
663 */
664int spi_register_board_info(struct spi_board_info const *info, unsigned n)
665{
666 struct boardinfo *bi;
667 int i;
668
669 if (!n)
670 return -EINVAL;
671
672 bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
673 if (!bi)
674 return -ENOMEM;
675
676 for (i = 0; i < n; i++, bi++, info++) {
677 struct spi_master *master;
678
679 memcpy(&bi->board_info, info, sizeof(*info));
680 mutex_lock(&board_lock);
681 list_add_tail(&bi->list, &board_list);
682 list_for_each_entry(master, &spi_master_list, list)
683 spi_match_master_to_boardinfo(master, &bi->board_info);
684 mutex_unlock(&board_lock);
685 }
686
687 return 0;
688}
689
690/*-------------------------------------------------------------------------*/
691
692static void spi_set_cs(struct spi_device *spi, bool enable)
693{
694 if (spi->mode & SPI_CS_HIGH)
695 enable = !enable;
696
697 if (gpio_is_valid(spi->cs_gpio))
698 gpio_set_value(spi->cs_gpio, !enable);
699 else if (spi->master->set_cs)
700 spi->master->set_cs(spi, !enable);
701}
702
703#ifdef CONFIG_HAS_DMA
704static int spi_map_buf(struct spi_master *master, struct device *dev,
705 struct sg_table *sgt, void *buf, size_t len,
706 enum dma_data_direction dir)
707{
708 const bool vmalloced_buf = is_vmalloc_addr(buf);
709 unsigned int max_seg_size = dma_get_max_seg_size(dev);
710 int desc_len;
711 int sgs;
712 struct page *vm_page;
713 void *sg_buf;
714 size_t min;
715 int i, ret;
716
717 if (vmalloced_buf) {
718 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
719 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
720 } else {
721 desc_len = min_t(int, max_seg_size, master->max_dma_len);
722 sgs = DIV_ROUND_UP(len, desc_len);
723 }
724
725 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
726 if (ret != 0)
727 return ret;
728
729 for (i = 0; i < sgs; i++) {
730
731 if (vmalloced_buf) {
732 min = min_t(size_t,
733 len, desc_len - offset_in_page(buf));
734 vm_page = vmalloc_to_page(buf);
735 if (!vm_page) {
736 sg_free_table(sgt);
737 return -ENOMEM;
738 }
739 sg_set_page(&sgt->sgl[i], vm_page,
740 min, offset_in_page(buf));
741 } else {
742 min = min_t(size_t, len, desc_len);
743 sg_buf = buf;
744 sg_set_buf(&sgt->sgl[i], sg_buf, min);
745 }
746
747 buf += min;
748 len -= min;
749 }
750
751 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
752 if (!ret)
753 ret = -ENOMEM;
754 if (ret < 0) {
755 sg_free_table(sgt);
756 return ret;
757 }
758
759 sgt->nents = ret;
760
761 return 0;
762}
763
764static void spi_unmap_buf(struct spi_master *master, struct device *dev,
765 struct sg_table *sgt, enum dma_data_direction dir)
766{
767 if (sgt->orig_nents) {
768 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
769 sg_free_table(sgt);
770 }
771}
772
773static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
774{
775 struct device *tx_dev, *rx_dev;
776 struct spi_transfer *xfer;
777 int ret;
778
779 if (!master->can_dma)
780 return 0;
781
782 if (master->dma_tx)
783 tx_dev = master->dma_tx->device->dev;
784 else
785 tx_dev = &master->dev;
786
787 if (master->dma_rx)
788 rx_dev = master->dma_rx->device->dev;
789 else
790 rx_dev = &master->dev;
791
792 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
793 if (!master->can_dma(master, msg->spi, xfer))
794 continue;
795
796 if (xfer->tx_buf != NULL) {
797 ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
798 (void *)xfer->tx_buf, xfer->len,
799 DMA_TO_DEVICE);
800 if (ret != 0)
801 return ret;
802 }
803
804 if (xfer->rx_buf != NULL) {
805 ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
806 xfer->rx_buf, xfer->len,
807 DMA_FROM_DEVICE);
808 if (ret != 0) {
809 spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
810 DMA_TO_DEVICE);
811 return ret;
812 }
813 }
814 }
815
816 master->cur_msg_mapped = true;
817
818 return 0;
819}
820
821static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
822{
823 struct spi_transfer *xfer;
824 struct device *tx_dev, *rx_dev;
825
826 if (!master->cur_msg_mapped || !master->can_dma)
827 return 0;
828
829 if (master->dma_tx)
830 tx_dev = master->dma_tx->device->dev;
831 else
832 tx_dev = &master->dev;
833
834 if (master->dma_rx)
835 rx_dev = master->dma_rx->device->dev;
836 else
837 rx_dev = &master->dev;
838
839 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
840 if (!master->can_dma(master, msg->spi, xfer))
841 continue;
842
843 spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
844 spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
845 }
846
847 return 0;
848}
849#else /* !CONFIG_HAS_DMA */
850static inline int __spi_map_msg(struct spi_master *master,
851 struct spi_message *msg)
852{
853 return 0;
854}
855
856static inline int __spi_unmap_msg(struct spi_master *master,
857 struct spi_message *msg)
858{
859 return 0;
860}
861#endif /* !CONFIG_HAS_DMA */
862
863static inline int spi_unmap_msg(struct spi_master *master,
864 struct spi_message *msg)
865{
866 struct spi_transfer *xfer;
867
868 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
869 /*
870 * Restore the original value of tx_buf or rx_buf if they are
871 * NULL.
872 */
873 if (xfer->tx_buf == master->dummy_tx)
874 xfer->tx_buf = NULL;
875 if (xfer->rx_buf == master->dummy_rx)
876 xfer->rx_buf = NULL;
877 }
878
879 return __spi_unmap_msg(master, msg);
880}
881
882static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
883{
884 struct spi_transfer *xfer;
885 void *tmp;
886 unsigned int max_tx, max_rx;
887
888 if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
889 max_tx = 0;
890 max_rx = 0;
891
892 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
893 if ((master->flags & SPI_MASTER_MUST_TX) &&
894 !xfer->tx_buf)
895 max_tx = max(xfer->len, max_tx);
896 if ((master->flags & SPI_MASTER_MUST_RX) &&
897 !xfer->rx_buf)
898 max_rx = max(xfer->len, max_rx);
899 }
900
901 if (max_tx) {
902 tmp = krealloc(master->dummy_tx, max_tx,
903 GFP_KERNEL | GFP_DMA);
904 if (!tmp)
905 return -ENOMEM;
906 master->dummy_tx = tmp;
907 memset(tmp, 0, max_tx);
908 }
909
910 if (max_rx) {
911 tmp = krealloc(master->dummy_rx, max_rx,
912 GFP_KERNEL | GFP_DMA);
913 if (!tmp)
914 return -ENOMEM;
915 master->dummy_rx = tmp;
916 }
917
918 if (max_tx || max_rx) {
919 list_for_each_entry(xfer, &msg->transfers,
920 transfer_list) {
921 if (!xfer->tx_buf)
922 xfer->tx_buf = master->dummy_tx;
923 if (!xfer->rx_buf)
924 xfer->rx_buf = master->dummy_rx;
925 }
926 }
927 }
928
929 return __spi_map_msg(master, msg);
930}
931
932/*
933 * spi_transfer_one_message - Default implementation of transfer_one_message()
934 *
935 * This is a standard implementation of transfer_one_message() for
936 * drivers which impelment a transfer_one() operation. It provides
937 * standard handling of delays and chip select management.
938 */
939static int spi_transfer_one_message(struct spi_master *master,
940 struct spi_message *msg)
941{
942 struct spi_transfer *xfer;
943 bool keep_cs = false;
944 int ret = 0;
945 unsigned long ms = 1;
946 struct spi_statistics *statm = &master->statistics;
947 struct spi_statistics *stats = &msg->spi->statistics;
948
949 spi_set_cs(msg->spi, true);
950
951 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
952 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
953
954 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
955 trace_spi_transfer_start(msg, xfer);
956
957 spi_statistics_add_transfer_stats(statm, xfer, master);
958 spi_statistics_add_transfer_stats(stats, xfer, master);
959
960 if (xfer->tx_buf || xfer->rx_buf) {
961 reinit_completion(&master->xfer_completion);
962
963 ret = master->transfer_one(master, msg->spi, xfer);
964 if (ret < 0) {
965 SPI_STATISTICS_INCREMENT_FIELD(statm,
966 errors);
967 SPI_STATISTICS_INCREMENT_FIELD(stats,
968 errors);
969 dev_err(&msg->spi->dev,
970 "SPI transfer failed: %d\n", ret);
971 goto out;
972 }
973
974 if (ret > 0) {
975 ret = 0;
976 ms = xfer->len * 8 * 1000 / xfer->speed_hz;
977 ms += ms + 100; /* some tolerance */
978
979 ms = wait_for_completion_timeout(&master->xfer_completion,
980 msecs_to_jiffies(ms));
981 }
982
983 if (ms == 0) {
984 SPI_STATISTICS_INCREMENT_FIELD(statm,
985 timedout);
986 SPI_STATISTICS_INCREMENT_FIELD(stats,
987 timedout);
988 dev_err(&msg->spi->dev,
989 "SPI transfer timed out\n");
990 msg->status = -ETIMEDOUT;
991 }
992 } else {
993 if (xfer->len)
994 dev_err(&msg->spi->dev,
995 "Bufferless transfer has length %u\n",
996 xfer->len);
997 }
998
999 trace_spi_transfer_stop(msg, xfer);
1000
1001 if (msg->status != -EINPROGRESS)
1002 goto out;
1003
1004 if (xfer->delay_usecs)
1005 udelay(xfer->delay_usecs);
1006
1007 if (xfer->cs_change) {
1008 if (list_is_last(&xfer->transfer_list,
1009 &msg->transfers)) {
1010 keep_cs = true;
1011 } else {
1012 spi_set_cs(msg->spi, false);
1013 udelay(10);
1014 spi_set_cs(msg->spi, true);
1015 }
1016 }
1017
1018 msg->actual_length += xfer->len;
1019 }
1020
1021out:
1022 if (ret != 0 || !keep_cs)
1023 spi_set_cs(msg->spi, false);
1024
1025 if (msg->status == -EINPROGRESS)
1026 msg->status = ret;
1027
1028 if (msg->status && master->handle_err)
1029 master->handle_err(master, msg);
1030
1031 spi_res_release(master, msg);
1032
1033 spi_finalize_current_message(master);
1034
1035 return ret;
1036}
1037
1038/**
1039 * spi_finalize_current_transfer - report completion of a transfer
1040 * @master: the master reporting completion
1041 *
1042 * Called by SPI drivers using the core transfer_one_message()
1043 * implementation to notify it that the current interrupt driven
1044 * transfer has finished and the next one may be scheduled.
1045 */
1046void spi_finalize_current_transfer(struct spi_master *master)
1047{
1048 complete(&master->xfer_completion);
1049}
1050EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1051
1052/**
1053 * __spi_pump_messages - function which processes spi message queue
1054 * @master: master to process queue for
1055 * @in_kthread: true if we are in the context of the message pump thread
1056 * @bus_locked: true if the bus mutex is held when calling this function
1057 *
1058 * This function checks if there is any spi message in the queue that
1059 * needs processing and if so call out to the driver to initialize hardware
1060 * and transfer each message.
1061 *
1062 * Note that it is called both from the kthread itself and also from
1063 * inside spi_sync(); the queue extraction handling at the top of the
1064 * function should deal with this safely.
1065 */
1066static void __spi_pump_messages(struct spi_master *master, bool in_kthread,
1067 bool bus_locked)
1068{
1069 unsigned long flags;
1070 bool was_busy = false;
1071 int ret;
1072
1073 /* Lock queue */
1074 spin_lock_irqsave(&master->queue_lock, flags);
1075
1076 /* Make sure we are not already running a message */
1077 if (master->cur_msg) {
1078 spin_unlock_irqrestore(&master->queue_lock, flags);
1079 return;
1080 }
1081
1082 /* If another context is idling the device then defer */
1083 if (master->idling) {
1084 queue_kthread_work(&master->kworker, &master->pump_messages);
1085 spin_unlock_irqrestore(&master->queue_lock, flags);
1086 return;
1087 }
1088
1089 /* Check if the queue is idle */
1090 if (list_empty(&master->queue) || !master->running) {
1091 if (!master->busy) {
1092 spin_unlock_irqrestore(&master->queue_lock, flags);
1093 return;
1094 }
1095
1096 /* Only do teardown in the thread */
1097 if (!in_kthread) {
1098 queue_kthread_work(&master->kworker,
1099 &master->pump_messages);
1100 spin_unlock_irqrestore(&master->queue_lock, flags);
1101 return;
1102 }
1103
1104 master->busy = false;
1105 master->idling = true;
1106 spin_unlock_irqrestore(&master->queue_lock, flags);
1107
1108 kfree(master->dummy_rx);
1109 master->dummy_rx = NULL;
1110 kfree(master->dummy_tx);
1111 master->dummy_tx = NULL;
1112 if (master->unprepare_transfer_hardware &&
1113 master->unprepare_transfer_hardware(master))
1114 dev_err(&master->dev,
1115 "failed to unprepare transfer hardware\n");
1116 if (master->auto_runtime_pm) {
1117 pm_runtime_mark_last_busy(master->dev.parent);
1118 pm_runtime_put_autosuspend(master->dev.parent);
1119 }
1120 trace_spi_master_idle(master);
1121
1122 spin_lock_irqsave(&master->queue_lock, flags);
1123 master->idling = false;
1124 spin_unlock_irqrestore(&master->queue_lock, flags);
1125 return;
1126 }
1127
1128 /* Extract head of queue */
1129 master->cur_msg =
1130 list_first_entry(&master->queue, struct spi_message, queue);
1131
1132 list_del_init(&master->cur_msg->queue);
1133 if (master->busy)
1134 was_busy = true;
1135 else
1136 master->busy = true;
1137 spin_unlock_irqrestore(&master->queue_lock, flags);
1138
1139 if (!was_busy && master->auto_runtime_pm) {
1140 ret = pm_runtime_get_sync(master->dev.parent);
1141 if (ret < 0) {
1142 dev_err(&master->dev, "Failed to power device: %d\n",
1143 ret);
1144 return;
1145 }
1146 }
1147
1148 if (!was_busy)
1149 trace_spi_master_busy(master);
1150
1151 if (!was_busy && master->prepare_transfer_hardware) {
1152 ret = master->prepare_transfer_hardware(master);
1153 if (ret) {
1154 dev_err(&master->dev,
1155 "failed to prepare transfer hardware\n");
1156
1157 if (master->auto_runtime_pm)
1158 pm_runtime_put(master->dev.parent);
1159 return;
1160 }
1161 }
1162
1163 if (!bus_locked)
1164 mutex_lock(&master->bus_lock_mutex);
1165
1166 trace_spi_message_start(master->cur_msg);
1167
1168 if (master->prepare_message) {
1169 ret = master->prepare_message(master, master->cur_msg);
1170 if (ret) {
1171 dev_err(&master->dev,
1172 "failed to prepare message: %d\n", ret);
1173 master->cur_msg->status = ret;
1174 spi_finalize_current_message(master);
1175 goto out;
1176 }
1177 master->cur_msg_prepared = true;
1178 }
1179
1180 ret = spi_map_msg(master, master->cur_msg);
1181 if (ret) {
1182 master->cur_msg->status = ret;
1183 spi_finalize_current_message(master);
1184 goto out;
1185 }
1186
1187 ret = master->transfer_one_message(master, master->cur_msg);
1188 if (ret) {
1189 dev_err(&master->dev,
1190 "failed to transfer one message from queue\n");
1191 goto out;
1192 }
1193
1194out:
1195 if (!bus_locked)
1196 mutex_unlock(&master->bus_lock_mutex);
1197
1198 /* Prod the scheduler in case transfer_one() was busy waiting */
1199 if (!ret)
1200 cond_resched();
1201}
1202
1203/**
1204 * spi_pump_messages - kthread work function which processes spi message queue
1205 * @work: pointer to kthread work struct contained in the master struct
1206 */
1207static void spi_pump_messages(struct kthread_work *work)
1208{
1209 struct spi_master *master =
1210 container_of(work, struct spi_master, pump_messages);
1211
1212 __spi_pump_messages(master, true, master->bus_lock_flag);
1213}
1214
1215static int spi_init_queue(struct spi_master *master)
1216{
1217 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1218
1219 master->running = false;
1220 master->busy = false;
1221
1222 init_kthread_worker(&master->kworker);
1223 master->kworker_task = kthread_run(kthread_worker_fn,
1224 &master->kworker, "%s",
1225 dev_name(&master->dev));
1226 if (IS_ERR(master->kworker_task)) {
1227 dev_err(&master->dev, "failed to create message pump task\n");
1228 return PTR_ERR(master->kworker_task);
1229 }
1230 init_kthread_work(&master->pump_messages, spi_pump_messages);
1231
1232 /*
1233 * Master config will indicate if this controller should run the
1234 * message pump with high (realtime) priority to reduce the transfer
1235 * latency on the bus by minimising the delay between a transfer
1236 * request and the scheduling of the message pump thread. Without this
1237 * setting the message pump thread will remain at default priority.
1238 */
1239 if (master->rt) {
1240 dev_info(&master->dev,
1241 "will run message pump with realtime priority\n");
1242 sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m);
1243 }
1244
1245 return 0;
1246}
1247
1248/**
1249 * spi_get_next_queued_message() - called by driver to check for queued
1250 * messages
1251 * @master: the master to check for queued messages
1252 *
1253 * If there are more messages in the queue, the next message is returned from
1254 * this call.
1255 *
1256 * Return: the next message in the queue, else NULL if the queue is empty.
1257 */
1258struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1259{
1260 struct spi_message *next;
1261 unsigned long flags;
1262
1263 /* get a pointer to the next message, if any */
1264 spin_lock_irqsave(&master->queue_lock, flags);
1265 next = list_first_entry_or_null(&master->queue, struct spi_message,
1266 queue);
1267 spin_unlock_irqrestore(&master->queue_lock, flags);
1268
1269 return next;
1270}
1271EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1272
1273/**
1274 * spi_finalize_current_message() - the current message is complete
1275 * @master: the master to return the message to
1276 *
1277 * Called by the driver to notify the core that the message in the front of the
1278 * queue is complete and can be removed from the queue.
1279 */
1280void spi_finalize_current_message(struct spi_master *master)
1281{
1282 struct spi_message *mesg;
1283 unsigned long flags;
1284 int ret;
1285
1286 spin_lock_irqsave(&master->queue_lock, flags);
1287 mesg = master->cur_msg;
1288 spin_unlock_irqrestore(&master->queue_lock, flags);
1289
1290 spi_unmap_msg(master, mesg);
1291
1292 if (master->cur_msg_prepared && master->unprepare_message) {
1293 ret = master->unprepare_message(master, mesg);
1294 if (ret) {
1295 dev_err(&master->dev,
1296 "failed to unprepare message: %d\n", ret);
1297 }
1298 }
1299
1300 spin_lock_irqsave(&master->queue_lock, flags);
1301 master->cur_msg = NULL;
1302 master->cur_msg_prepared = false;
1303 queue_kthread_work(&master->kworker, &master->pump_messages);
1304 spin_unlock_irqrestore(&master->queue_lock, flags);
1305
1306 trace_spi_message_done(mesg);
1307
1308 mesg->state = NULL;
1309 if (mesg->complete)
1310 mesg->complete(mesg->context);
1311}
1312EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1313
1314static int spi_start_queue(struct spi_master *master)
1315{
1316 unsigned long flags;
1317
1318 spin_lock_irqsave(&master->queue_lock, flags);
1319
1320 if (master->running || master->busy) {
1321 spin_unlock_irqrestore(&master->queue_lock, flags);
1322 return -EBUSY;
1323 }
1324
1325 master->running = true;
1326 master->cur_msg = NULL;
1327 spin_unlock_irqrestore(&master->queue_lock, flags);
1328
1329 queue_kthread_work(&master->kworker, &master->pump_messages);
1330
1331 return 0;
1332}
1333
1334static int spi_stop_queue(struct spi_master *master)
1335{
1336 unsigned long flags;
1337 unsigned limit = 500;
1338 int ret = 0;
1339
1340 spin_lock_irqsave(&master->queue_lock, flags);
1341
1342 /*
1343 * This is a bit lame, but is optimized for the common execution path.
1344 * A wait_queue on the master->busy could be used, but then the common
1345 * execution path (pump_messages) would be required to call wake_up or
1346 * friends on every SPI message. Do this instead.
1347 */
1348 while ((!list_empty(&master->queue) || master->busy) && limit--) {
1349 spin_unlock_irqrestore(&master->queue_lock, flags);
1350 usleep_range(10000, 11000);
1351 spin_lock_irqsave(&master->queue_lock, flags);
1352 }
1353
1354 if (!list_empty(&master->queue) || master->busy)
1355 ret = -EBUSY;
1356 else
1357 master->running = false;
1358
1359 spin_unlock_irqrestore(&master->queue_lock, flags);
1360
1361 if (ret) {
1362 dev_warn(&master->dev,
1363 "could not stop message queue\n");
1364 return ret;
1365 }
1366 return ret;
1367}
1368
1369static int spi_destroy_queue(struct spi_master *master)
1370{
1371 int ret;
1372
1373 ret = spi_stop_queue(master);
1374
1375 /*
1376 * flush_kthread_worker will block until all work is done.
1377 * If the reason that stop_queue timed out is that the work will never
1378 * finish, then it does no good to call flush/stop thread, so
1379 * return anyway.
1380 */
1381 if (ret) {
1382 dev_err(&master->dev, "problem destroying queue\n");
1383 return ret;
1384 }
1385
1386 flush_kthread_worker(&master->kworker);
1387 kthread_stop(master->kworker_task);
1388
1389 return 0;
1390}
1391
1392static int __spi_queued_transfer(struct spi_device *spi,
1393 struct spi_message *msg,
1394 bool need_pump)
1395{
1396 struct spi_master *master = spi->master;
1397 unsigned long flags;
1398
1399 spin_lock_irqsave(&master->queue_lock, flags);
1400
1401 if (!master->running) {
1402 spin_unlock_irqrestore(&master->queue_lock, flags);
1403 return -ESHUTDOWN;
1404 }
1405 msg->actual_length = 0;
1406 msg->status = -EINPROGRESS;
1407
1408 list_add_tail(&msg->queue, &master->queue);
1409 if (!master->busy && need_pump)
1410 queue_kthread_work(&master->kworker, &master->pump_messages);
1411
1412 spin_unlock_irqrestore(&master->queue_lock, flags);
1413 return 0;
1414}
1415
1416/**
1417 * spi_queued_transfer - transfer function for queued transfers
1418 * @spi: spi device which is requesting transfer
1419 * @msg: spi message which is to handled is queued to driver queue
1420 *
1421 * Return: zero on success, else a negative error code.
1422 */
1423static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1424{
1425 return __spi_queued_transfer(spi, msg, true);
1426}
1427
1428static int spi_master_initialize_queue(struct spi_master *master)
1429{
1430 int ret;
1431
1432 master->transfer = spi_queued_transfer;
1433 if (!master->transfer_one_message)
1434 master->transfer_one_message = spi_transfer_one_message;
1435
1436 /* Initialize and start queue */
1437 ret = spi_init_queue(master);
1438 if (ret) {
1439 dev_err(&master->dev, "problem initializing queue\n");
1440 goto err_init_queue;
1441 }
1442 master->queued = true;
1443 ret = spi_start_queue(master);
1444 if (ret) {
1445 dev_err(&master->dev, "problem starting queue\n");
1446 goto err_start_queue;
1447 }
1448
1449 return 0;
1450
1451err_start_queue:
1452 spi_destroy_queue(master);
1453err_init_queue:
1454 return ret;
1455}
1456
1457/*-------------------------------------------------------------------------*/
1458
1459#if defined(CONFIG_OF)
1460static struct spi_device *
1461of_register_spi_device(struct spi_master *master, struct device_node *nc)
1462{
1463 struct spi_device *spi;
1464 int rc;
1465 u32 value;
1466
1467 /* Alloc an spi_device */
1468 spi = spi_alloc_device(master);
1469 if (!spi) {
1470 dev_err(&master->dev, "spi_device alloc error for %s\n",
1471 nc->full_name);
1472 rc = -ENOMEM;
1473 goto err_out;
1474 }
1475
1476 /* Select device driver */
1477 rc = of_modalias_node(nc, spi->modalias,
1478 sizeof(spi->modalias));
1479 if (rc < 0) {
1480 dev_err(&master->dev, "cannot find modalias for %s\n",
1481 nc->full_name);
1482 goto err_out;
1483 }
1484
1485 /* Device address */
1486 rc = of_property_read_u32(nc, "reg", &value);
1487 if (rc) {
1488 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1489 nc->full_name, rc);
1490 goto err_out;
1491 }
1492 spi->chip_select = value;
1493
1494 /* Mode (clock phase/polarity/etc.) */
1495 if (of_find_property(nc, "spi-cpha", NULL))
1496 spi->mode |= SPI_CPHA;
1497 if (of_find_property(nc, "spi-cpol", NULL))
1498 spi->mode |= SPI_CPOL;
1499 if (of_find_property(nc, "spi-cs-high", NULL))
1500 spi->mode |= SPI_CS_HIGH;
1501 if (of_find_property(nc, "spi-3wire", NULL))
1502 spi->mode |= SPI_3WIRE;
1503 if (of_find_property(nc, "spi-lsb-first", NULL))
1504 spi->mode |= SPI_LSB_FIRST;
1505
1506 /* Device DUAL/QUAD mode */
1507 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1508 switch (value) {
1509 case 1:
1510 break;
1511 case 2:
1512 spi->mode |= SPI_TX_DUAL;
1513 break;
1514 case 4:
1515 spi->mode |= SPI_TX_QUAD;
1516 break;
1517 default:
1518 dev_warn(&master->dev,
1519 "spi-tx-bus-width %d not supported\n",
1520 value);
1521 break;
1522 }
1523 }
1524
1525 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1526 switch (value) {
1527 case 1:
1528 break;
1529 case 2:
1530 spi->mode |= SPI_RX_DUAL;
1531 break;
1532 case 4:
1533 spi->mode |= SPI_RX_QUAD;
1534 break;
1535 default:
1536 dev_warn(&master->dev,
1537 "spi-rx-bus-width %d not supported\n",
1538 value);
1539 break;
1540 }
1541 }
1542
1543 /* Device speed */
1544 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1545 if (rc) {
1546 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1547 nc->full_name, rc);
1548 goto err_out;
1549 }
1550 spi->max_speed_hz = value;
1551
1552 /* Store a pointer to the node in the device structure */
1553 of_node_get(nc);
1554 spi->dev.of_node = nc;
1555
1556 /* Register the new device */
1557 rc = spi_add_device(spi);
1558 if (rc) {
1559 dev_err(&master->dev, "spi_device register error %s\n",
1560 nc->full_name);
1561 goto err_out;
1562 }
1563
1564 return spi;
1565
1566err_out:
1567 spi_dev_put(spi);
1568 return ERR_PTR(rc);
1569}
1570
1571/**
1572 * of_register_spi_devices() - Register child devices onto the SPI bus
1573 * @master: Pointer to spi_master device
1574 *
1575 * Registers an spi_device for each child node of master node which has a 'reg'
1576 * property.
1577 */
1578static void of_register_spi_devices(struct spi_master *master)
1579{
1580 struct spi_device *spi;
1581 struct device_node *nc;
1582
1583 if (!master->dev.of_node)
1584 return;
1585
1586 for_each_available_child_of_node(master->dev.of_node, nc) {
1587 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1588 continue;
1589 spi = of_register_spi_device(master, nc);
1590 if (IS_ERR(spi))
1591 dev_warn(&master->dev, "Failed to create SPI device for %s\n",
1592 nc->full_name);
1593 }
1594}
1595#else
1596static void of_register_spi_devices(struct spi_master *master) { }
1597#endif
1598
1599#ifdef CONFIG_ACPI
1600static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1601{
1602 struct spi_device *spi = data;
1603 struct spi_master *master = spi->master;
1604
1605 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1606 struct acpi_resource_spi_serialbus *sb;
1607
1608 sb = &ares->data.spi_serial_bus;
1609 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1610 /*
1611 * ACPI DeviceSelection numbering is handled by the
1612 * host controller driver in Windows and can vary
1613 * from driver to driver. In Linux we always expect
1614 * 0 .. max - 1 so we need to ask the driver to
1615 * translate between the two schemes.
1616 */
1617 if (master->fw_translate_cs) {
1618 int cs = master->fw_translate_cs(master,
1619 sb->device_selection);
1620 if (cs < 0)
1621 return cs;
1622 spi->chip_select = cs;
1623 } else {
1624 spi->chip_select = sb->device_selection;
1625 }
1626
1627 spi->max_speed_hz = sb->connection_speed;
1628
1629 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1630 spi->mode |= SPI_CPHA;
1631 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1632 spi->mode |= SPI_CPOL;
1633 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1634 spi->mode |= SPI_CS_HIGH;
1635 }
1636 } else if (spi->irq < 0) {
1637 struct resource r;
1638
1639 if (acpi_dev_resource_interrupt(ares, 0, &r))
1640 spi->irq = r.start;
1641 }
1642
1643 /* Always tell the ACPI core to skip this resource */
1644 return 1;
1645}
1646
1647static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1648 void *data, void **return_value)
1649{
1650 struct spi_master *master = data;
1651 struct list_head resource_list;
1652 struct acpi_device *adev;
1653 struct spi_device *spi;
1654 int ret;
1655
1656 if (acpi_bus_get_device(handle, &adev))
1657 return AE_OK;
1658 if (acpi_bus_get_status(adev) || !adev->status.present)
1659 return AE_OK;
1660
1661 spi = spi_alloc_device(master);
1662 if (!spi) {
1663 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1664 dev_name(&adev->dev));
1665 return AE_NO_MEMORY;
1666 }
1667
1668 ACPI_COMPANION_SET(&spi->dev, adev);
1669 spi->irq = -1;
1670
1671 INIT_LIST_HEAD(&resource_list);
1672 ret = acpi_dev_get_resources(adev, &resource_list,
1673 acpi_spi_add_resource, spi);
1674 acpi_dev_free_resource_list(&resource_list);
1675
1676 if (ret < 0 || !spi->max_speed_hz) {
1677 spi_dev_put(spi);
1678 return AE_OK;
1679 }
1680
1681 if (spi->irq < 0)
1682 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1683
1684 adev->power.flags.ignore_parent = true;
1685 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
1686 if (spi_add_device(spi)) {
1687 adev->power.flags.ignore_parent = false;
1688 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1689 dev_name(&adev->dev));
1690 spi_dev_put(spi);
1691 }
1692
1693 return AE_OK;
1694}
1695
1696static void acpi_register_spi_devices(struct spi_master *master)
1697{
1698 acpi_status status;
1699 acpi_handle handle;
1700
1701 handle = ACPI_HANDLE(master->dev.parent);
1702 if (!handle)
1703 return;
1704
1705 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1706 acpi_spi_add_device, NULL,
1707 master, NULL);
1708 if (ACPI_FAILURE(status))
1709 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1710}
1711#else
1712static inline void acpi_register_spi_devices(struct spi_master *master) {}
1713#endif /* CONFIG_ACPI */
1714
1715static void spi_master_release(struct device *dev)
1716{
1717 struct spi_master *master;
1718
1719 master = container_of(dev, struct spi_master, dev);
1720 kfree(master);
1721}
1722
1723static struct class spi_master_class = {
1724 .name = "spi_master",
1725 .owner = THIS_MODULE,
1726 .dev_release = spi_master_release,
1727 .dev_groups = spi_master_groups,
1728};
1729
1730
1731/**
1732 * spi_alloc_master - allocate SPI master controller
1733 * @dev: the controller, possibly using the platform_bus
1734 * @size: how much zeroed driver-private data to allocate; the pointer to this
1735 * memory is in the driver_data field of the returned device,
1736 * accessible with spi_master_get_devdata().
1737 * Context: can sleep
1738 *
1739 * This call is used only by SPI master controller drivers, which are the
1740 * only ones directly touching chip registers. It's how they allocate
1741 * an spi_master structure, prior to calling spi_register_master().
1742 *
1743 * This must be called from context that can sleep.
1744 *
1745 * The caller is responsible for assigning the bus number and initializing
1746 * the master's methods before calling spi_register_master(); and (after errors
1747 * adding the device) calling spi_master_put() to prevent a memory leak.
1748 *
1749 * Return: the SPI master structure on success, else NULL.
1750 */
1751struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
1752{
1753 struct spi_master *master;
1754
1755 if (!dev)
1756 return NULL;
1757
1758 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
1759 if (!master)
1760 return NULL;
1761
1762 device_initialize(&master->dev);
1763 master->bus_num = -1;
1764 master->num_chipselect = 1;
1765 master->dev.class = &spi_master_class;
1766 master->dev.parent = dev;
1767 spi_master_set_devdata(master, &master[1]);
1768
1769 return master;
1770}
1771EXPORT_SYMBOL_GPL(spi_alloc_master);
1772
1773#ifdef CONFIG_OF
1774static int of_spi_register_master(struct spi_master *master)
1775{
1776 int nb, i, *cs;
1777 struct device_node *np = master->dev.of_node;
1778
1779 if (!np)
1780 return 0;
1781
1782 nb = of_gpio_named_count(np, "cs-gpios");
1783 master->num_chipselect = max_t(int, nb, master->num_chipselect);
1784
1785 /* Return error only for an incorrectly formed cs-gpios property */
1786 if (nb == 0 || nb == -ENOENT)
1787 return 0;
1788 else if (nb < 0)
1789 return nb;
1790
1791 cs = devm_kzalloc(&master->dev,
1792 sizeof(int) * master->num_chipselect,
1793 GFP_KERNEL);
1794 master->cs_gpios = cs;
1795
1796 if (!master->cs_gpios)
1797 return -ENOMEM;
1798
1799 for (i = 0; i < master->num_chipselect; i++)
1800 cs[i] = -ENOENT;
1801
1802 for (i = 0; i < nb; i++)
1803 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1804
1805 return 0;
1806}
1807#else
1808static int of_spi_register_master(struct spi_master *master)
1809{
1810 return 0;
1811}
1812#endif
1813
1814/**
1815 * spi_register_master - register SPI master controller
1816 * @master: initialized master, originally from spi_alloc_master()
1817 * Context: can sleep
1818 *
1819 * SPI master controllers connect to their drivers using some non-SPI bus,
1820 * such as the platform bus. The final stage of probe() in that code
1821 * includes calling spi_register_master() to hook up to this SPI bus glue.
1822 *
1823 * SPI controllers use board specific (often SOC specific) bus numbers,
1824 * and board-specific addressing for SPI devices combines those numbers
1825 * with chip select numbers. Since SPI does not directly support dynamic
1826 * device identification, boards need configuration tables telling which
1827 * chip is at which address.
1828 *
1829 * This must be called from context that can sleep. It returns zero on
1830 * success, else a negative error code (dropping the master's refcount).
1831 * After a successful return, the caller is responsible for calling
1832 * spi_unregister_master().
1833 *
1834 * Return: zero on success, else a negative error code.
1835 */
1836int spi_register_master(struct spi_master *master)
1837{
1838 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
1839 struct device *dev = master->dev.parent;
1840 struct boardinfo *bi;
1841 int status = -ENODEV;
1842 int dynamic = 0;
1843
1844 if (!dev)
1845 return -ENODEV;
1846
1847 status = of_spi_register_master(master);
1848 if (status)
1849 return status;
1850
1851 /* even if it's just one always-selected device, there must
1852 * be at least one chipselect
1853 */
1854 if (master->num_chipselect == 0)
1855 return -EINVAL;
1856
1857 if ((master->bus_num < 0) && master->dev.of_node)
1858 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1859
1860 /* convention: dynamically assigned bus IDs count down from the max */
1861 if (master->bus_num < 0) {
1862 /* FIXME switch to an IDR based scheme, something like
1863 * I2C now uses, so we can't run out of "dynamic" IDs
1864 */
1865 master->bus_num = atomic_dec_return(&dyn_bus_id);
1866 dynamic = 1;
1867 }
1868
1869 INIT_LIST_HEAD(&master->queue);
1870 spin_lock_init(&master->queue_lock);
1871 spin_lock_init(&master->bus_lock_spinlock);
1872 mutex_init(&master->bus_lock_mutex);
1873 master->bus_lock_flag = 0;
1874 init_completion(&master->xfer_completion);
1875 if (!master->max_dma_len)
1876 master->max_dma_len = INT_MAX;
1877
1878 /* register the device, then userspace will see it.
1879 * registration fails if the bus ID is in use.
1880 */
1881 dev_set_name(&master->dev, "spi%u", master->bus_num);
1882 status = device_add(&master->dev);
1883 if (status < 0)
1884 goto done;
1885 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
1886 dynamic ? " (dynamic)" : "");
1887
1888 /* If we're using a queued driver, start the queue */
1889 if (master->transfer)
1890 dev_info(dev, "master is unqueued, this is deprecated\n");
1891 else {
1892 status = spi_master_initialize_queue(master);
1893 if (status) {
1894 device_del(&master->dev);
1895 goto done;
1896 }
1897 }
1898 /* add statistics */
1899 spin_lock_init(&master->statistics.lock);
1900
1901 mutex_lock(&board_lock);
1902 list_add_tail(&master->list, &spi_master_list);
1903 list_for_each_entry(bi, &board_list, list)
1904 spi_match_master_to_boardinfo(master, &bi->board_info);
1905 mutex_unlock(&board_lock);
1906
1907 /* Register devices from the device tree and ACPI */
1908 of_register_spi_devices(master);
1909 acpi_register_spi_devices(master);
1910done:
1911 return status;
1912}
1913EXPORT_SYMBOL_GPL(spi_register_master);
1914
1915static void devm_spi_unregister(struct device *dev, void *res)
1916{
1917 spi_unregister_master(*(struct spi_master **)res);
1918}
1919
1920/**
1921 * dev_spi_register_master - register managed SPI master controller
1922 * @dev: device managing SPI master
1923 * @master: initialized master, originally from spi_alloc_master()
1924 * Context: can sleep
1925 *
1926 * Register a SPI device as with spi_register_master() which will
1927 * automatically be unregister
1928 *
1929 * Return: zero on success, else a negative error code.
1930 */
1931int devm_spi_register_master(struct device *dev, struct spi_master *master)
1932{
1933 struct spi_master **ptr;
1934 int ret;
1935
1936 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
1937 if (!ptr)
1938 return -ENOMEM;
1939
1940 ret = spi_register_master(master);
1941 if (!ret) {
1942 *ptr = master;
1943 devres_add(dev, ptr);
1944 } else {
1945 devres_free(ptr);
1946 }
1947
1948 return ret;
1949}
1950EXPORT_SYMBOL_GPL(devm_spi_register_master);
1951
1952static int __unregister(struct device *dev, void *null)
1953{
1954 spi_unregister_device(to_spi_device(dev));
1955 return 0;
1956}
1957
1958/**
1959 * spi_unregister_master - unregister SPI master controller
1960 * @master: the master being unregistered
1961 * Context: can sleep
1962 *
1963 * This call is used only by SPI master controller drivers, which are the
1964 * only ones directly touching chip registers.
1965 *
1966 * This must be called from context that can sleep.
1967 */
1968void spi_unregister_master(struct spi_master *master)
1969{
1970 int dummy;
1971
1972 if (master->queued) {
1973 if (spi_destroy_queue(master))
1974 dev_err(&master->dev, "queue remove failed\n");
1975 }
1976
1977 mutex_lock(&board_lock);
1978 list_del(&master->list);
1979 mutex_unlock(&board_lock);
1980
1981 dummy = device_for_each_child(&master->dev, NULL, __unregister);
1982 device_unregister(&master->dev);
1983}
1984EXPORT_SYMBOL_GPL(spi_unregister_master);
1985
1986int spi_master_suspend(struct spi_master *master)
1987{
1988 int ret;
1989
1990 /* Basically no-ops for non-queued masters */
1991 if (!master->queued)
1992 return 0;
1993
1994 ret = spi_stop_queue(master);
1995 if (ret)
1996 dev_err(&master->dev, "queue stop failed\n");
1997
1998 return ret;
1999}
2000EXPORT_SYMBOL_GPL(spi_master_suspend);
2001
2002int spi_master_resume(struct spi_master *master)
2003{
2004 int ret;
2005
2006 if (!master->queued)
2007 return 0;
2008
2009 ret = spi_start_queue(master);
2010 if (ret)
2011 dev_err(&master->dev, "queue restart failed\n");
2012
2013 return ret;
2014}
2015EXPORT_SYMBOL_GPL(spi_master_resume);
2016
2017static int __spi_master_match(struct device *dev, const void *data)
2018{
2019 struct spi_master *m;
2020 const u16 *bus_num = data;
2021
2022 m = container_of(dev, struct spi_master, dev);
2023 return m->bus_num == *bus_num;
2024}
2025
2026/**
2027 * spi_busnum_to_master - look up master associated with bus_num
2028 * @bus_num: the master's bus number
2029 * Context: can sleep
2030 *
2031 * This call may be used with devices that are registered after
2032 * arch init time. It returns a refcounted pointer to the relevant
2033 * spi_master (which the caller must release), or NULL if there is
2034 * no such master registered.
2035 *
2036 * Return: the SPI master structure on success, else NULL.
2037 */
2038struct spi_master *spi_busnum_to_master(u16 bus_num)
2039{
2040 struct device *dev;
2041 struct spi_master *master = NULL;
2042
2043 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2044 __spi_master_match);
2045 if (dev)
2046 master = container_of(dev, struct spi_master, dev);
2047 /* reference got in class_find_device */
2048 return master;
2049}
2050EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2051
2052/*-------------------------------------------------------------------------*/
2053
2054/* Core methods for SPI resource management */
2055
2056/**
2057 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2058 * during the processing of a spi_message while using
2059 * spi_transfer_one
2060 * @spi: the spi device for which we allocate memory
2061 * @release: the release code to execute for this resource
2062 * @size: size to alloc and return
2063 * @gfp: GFP allocation flags
2064 *
2065 * Return: the pointer to the allocated data
2066 *
2067 * This may get enhanced in the future to allocate from a memory pool
2068 * of the @spi_device or @spi_master to avoid repeated allocations.
2069 */
2070void *spi_res_alloc(struct spi_device *spi,
2071 spi_res_release_t release,
2072 size_t size, gfp_t gfp)
2073{
2074 struct spi_res *sres;
2075
2076 sres = kzalloc(sizeof(*sres) + size, gfp);
2077 if (!sres)
2078 return NULL;
2079
2080 INIT_LIST_HEAD(&sres->entry);
2081 sres->release = release;
2082
2083 return sres->data;
2084}
2085EXPORT_SYMBOL_GPL(spi_res_alloc);
2086
2087/**
2088 * spi_res_free - free an spi resource
2089 * @res: pointer to the custom data of a resource
2090 *
2091 */
2092void spi_res_free(void *res)
2093{
2094 struct spi_res *sres = container_of(res, struct spi_res, data);
2095
2096 if (!res)
2097 return;
2098
2099 WARN_ON(!list_empty(&sres->entry));
2100 kfree(sres);
2101}
2102EXPORT_SYMBOL_GPL(spi_res_free);
2103
2104/**
2105 * spi_res_add - add a spi_res to the spi_message
2106 * @message: the spi message
2107 * @res: the spi_resource
2108 */
2109void spi_res_add(struct spi_message *message, void *res)
2110{
2111 struct spi_res *sres = container_of(res, struct spi_res, data);
2112
2113 WARN_ON(!list_empty(&sres->entry));
2114 list_add_tail(&sres->entry, &message->resources);
2115}
2116EXPORT_SYMBOL_GPL(spi_res_add);
2117
2118/**
2119 * spi_res_release - release all spi resources for this message
2120 * @master: the @spi_master
2121 * @message: the @spi_message
2122 */
2123void spi_res_release(struct spi_master *master,
2124 struct spi_message *message)
2125{
2126 struct spi_res *res;
2127
2128 while (!list_empty(&message->resources)) {
2129 res = list_last_entry(&message->resources,
2130 struct spi_res, entry);
2131
2132 if (res->release)
2133 res->release(master, message, res->data);
2134
2135 list_del(&res->entry);
2136
2137 kfree(res);
2138 }
2139}
2140EXPORT_SYMBOL_GPL(spi_res_release);
2141
2142/*-------------------------------------------------------------------------*/
2143
2144/* Core methods for spi_message alterations */
2145
2146static void __spi_replace_transfers_release(struct spi_master *master,
2147 struct spi_message *msg,
2148 void *res)
2149{
2150 struct spi_replaced_transfers *rxfer = res;
2151 size_t i;
2152
2153 /* call extra callback if requested */
2154 if (rxfer->release)
2155 rxfer->release(master, msg, res);
2156
2157 /* insert replaced transfers back into the message */
2158 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2159
2160 /* remove the formerly inserted entries */
2161 for (i = 0; i < rxfer->inserted; i++)
2162 list_del(&rxfer->inserted_transfers[i].transfer_list);
2163}
2164
2165/**
2166 * spi_replace_transfers - replace transfers with several transfers
2167 * and register change with spi_message.resources
2168 * @msg: the spi_message we work upon
2169 * @xfer_first: the first spi_transfer we want to replace
2170 * @remove: number of transfers to remove
2171 * @insert: the number of transfers we want to insert instead
2172 * @release: extra release code necessary in some circumstances
2173 * @extradatasize: extra data to allocate (with alignment guarantees
2174 * of struct @spi_transfer)
2175 * @gfp: gfp flags
2176 *
2177 * Returns: pointer to @spi_replaced_transfers,
2178 * PTR_ERR(...) in case of errors.
2179 */
2180struct spi_replaced_transfers *spi_replace_transfers(
2181 struct spi_message *msg,
2182 struct spi_transfer *xfer_first,
2183 size_t remove,
2184 size_t insert,
2185 spi_replaced_release_t release,
2186 size_t extradatasize,
2187 gfp_t gfp)
2188{
2189 struct spi_replaced_transfers *rxfer;
2190 struct spi_transfer *xfer;
2191 size_t i;
2192
2193 /* allocate the structure using spi_res */
2194 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2195 insert * sizeof(struct spi_transfer)
2196 + sizeof(struct spi_replaced_transfers)
2197 + extradatasize,
2198 gfp);
2199 if (!rxfer)
2200 return ERR_PTR(-ENOMEM);
2201
2202 /* the release code to invoke before running the generic release */
2203 rxfer->release = release;
2204
2205 /* assign extradata */
2206 if (extradatasize)
2207 rxfer->extradata =
2208 &rxfer->inserted_transfers[insert];
2209
2210 /* init the replaced_transfers list */
2211 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2212
2213 /* assign the list_entry after which we should reinsert
2214 * the @replaced_transfers - it may be spi_message.messages!
2215 */
2216 rxfer->replaced_after = xfer_first->transfer_list.prev;
2217
2218 /* remove the requested number of transfers */
2219 for (i = 0; i < remove; i++) {
2220 /* if the entry after replaced_after it is msg->transfers
2221 * then we have been requested to remove more transfers
2222 * than are in the list
2223 */
2224 if (rxfer->replaced_after->next == &msg->transfers) {
2225 dev_err(&msg->spi->dev,
2226 "requested to remove more spi_transfers than are available\n");
2227 /* insert replaced transfers back into the message */
2228 list_splice(&rxfer->replaced_transfers,
2229 rxfer->replaced_after);
2230
2231 /* free the spi_replace_transfer structure */
2232 spi_res_free(rxfer);
2233
2234 /* and return with an error */
2235 return ERR_PTR(-EINVAL);
2236 }
2237
2238 /* remove the entry after replaced_after from list of
2239 * transfers and add it to list of replaced_transfers
2240 */
2241 list_move_tail(rxfer->replaced_after->next,
2242 &rxfer->replaced_transfers);
2243 }
2244
2245 /* create copy of the given xfer with identical settings
2246 * based on the first transfer to get removed
2247 */
2248 for (i = 0; i < insert; i++) {
2249 /* we need to run in reverse order */
2250 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2251
2252 /* copy all spi_transfer data */
2253 memcpy(xfer, xfer_first, sizeof(*xfer));
2254
2255 /* add to list */
2256 list_add(&xfer->transfer_list, rxfer->replaced_after);
2257
2258 /* clear cs_change and delay_usecs for all but the last */
2259 if (i) {
2260 xfer->cs_change = false;
2261 xfer->delay_usecs = 0;
2262 }
2263 }
2264
2265 /* set up inserted */
2266 rxfer->inserted = insert;
2267
2268 /* and register it with spi_res/spi_message */
2269 spi_res_add(msg, rxfer);
2270
2271 return rxfer;
2272}
2273EXPORT_SYMBOL_GPL(spi_replace_transfers);
2274
2275static int __spi_split_transfer_maxsize(struct spi_master *master,
2276 struct spi_message *msg,
2277 struct spi_transfer **xferp,
2278 size_t maxsize,
2279 gfp_t gfp)
2280{
2281 struct spi_transfer *xfer = *xferp, *xfers;
2282 struct spi_replaced_transfers *srt;
2283 size_t offset;
2284 size_t count, i;
2285
2286 /* warn once about this fact that we are splitting a transfer */
2287 dev_warn_once(&msg->spi->dev,
2288 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2289 xfer->len, maxsize);
2290
2291 /* calculate how many we have to replace */
2292 count = DIV_ROUND_UP(xfer->len, maxsize);
2293
2294 /* create replacement */
2295 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
2296 if (IS_ERR(srt))
2297 return PTR_ERR(srt);
2298 xfers = srt->inserted_transfers;
2299
2300 /* now handle each of those newly inserted spi_transfers
2301 * note that the replacements spi_transfers all are preset
2302 * to the same values as *xferp, so tx_buf, rx_buf and len
2303 * are all identical (as well as most others)
2304 * so we just have to fix up len and the pointers.
2305 *
2306 * this also includes support for the depreciated
2307 * spi_message.is_dma_mapped interface
2308 */
2309
2310 /* the first transfer just needs the length modified, so we
2311 * run it outside the loop
2312 */
2313 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
2314
2315 /* all the others need rx_buf/tx_buf also set */
2316 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2317 /* update rx_buf, tx_buf and dma */
2318 if (xfers[i].rx_buf)
2319 xfers[i].rx_buf += offset;
2320 if (xfers[i].rx_dma)
2321 xfers[i].rx_dma += offset;
2322 if (xfers[i].tx_buf)
2323 xfers[i].tx_buf += offset;
2324 if (xfers[i].tx_dma)
2325 xfers[i].tx_dma += offset;
2326
2327 /* update length */
2328 xfers[i].len = min(maxsize, xfers[i].len - offset);
2329 }
2330
2331 /* we set up xferp to the last entry we have inserted,
2332 * so that we skip those already split transfers
2333 */
2334 *xferp = &xfers[count - 1];
2335
2336 /* increment statistics counters */
2337 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2338 transfers_split_maxsize);
2339 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2340 transfers_split_maxsize);
2341
2342 return 0;
2343}
2344
2345/**
2346 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2347 * when an individual transfer exceeds a
2348 * certain size
2349 * @master: the @spi_master for this transfer
2350 * @msg: the @spi_message to transform
2351 * @maxsize: the maximum when to apply this
2352 * @gfp: GFP allocation flags
2353 *
2354 * Return: status of transformation
2355 */
2356int spi_split_transfers_maxsize(struct spi_master *master,
2357 struct spi_message *msg,
2358 size_t maxsize,
2359 gfp_t gfp)
2360{
2361 struct spi_transfer *xfer;
2362 int ret;
2363
2364 /* iterate over the transfer_list,
2365 * but note that xfer is advanced to the last transfer inserted
2366 * to avoid checking sizes again unnecessarily (also xfer does
2367 * potentiall belong to a different list by the time the
2368 * replacement has happened
2369 */
2370 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2371 if (xfer->len > maxsize) {
2372 ret = __spi_split_transfer_maxsize(
2373 master, msg, &xfer, maxsize, gfp);
2374 if (ret)
2375 return ret;
2376 }
2377 }
2378
2379 return 0;
2380}
2381EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2382
2383/*-------------------------------------------------------------------------*/
2384
2385/* Core methods for SPI master protocol drivers. Some of the
2386 * other core methods are currently defined as inline functions.
2387 */
2388
2389static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2390{
2391 if (master->bits_per_word_mask) {
2392 /* Only 32 bits fit in the mask */
2393 if (bits_per_word > 32)
2394 return -EINVAL;
2395 if (!(master->bits_per_word_mask &
2396 SPI_BPW_MASK(bits_per_word)))
2397 return -EINVAL;
2398 }
2399
2400 return 0;
2401}
2402
2403/**
2404 * spi_setup - setup SPI mode and clock rate
2405 * @spi: the device whose settings are being modified
2406 * Context: can sleep, and no requests are queued to the device
2407 *
2408 * SPI protocol drivers may need to update the transfer mode if the
2409 * device doesn't work with its default. They may likewise need
2410 * to update clock rates or word sizes from initial values. This function
2411 * changes those settings, and must be called from a context that can sleep.
2412 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2413 * effect the next time the device is selected and data is transferred to
2414 * or from it. When this function returns, the spi device is deselected.
2415 *
2416 * Note that this call will fail if the protocol driver specifies an option
2417 * that the underlying controller or its driver does not support. For
2418 * example, not all hardware supports wire transfers using nine bit words,
2419 * LSB-first wire encoding, or active-high chipselects.
2420 *
2421 * Return: zero on success, else a negative error code.
2422 */
2423int spi_setup(struct spi_device *spi)
2424{
2425 unsigned bad_bits, ugly_bits;
2426 int status;
2427
2428 /* check mode to prevent that DUAL and QUAD set at the same time
2429 */
2430 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2431 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2432 dev_err(&spi->dev,
2433 "setup: can not select dual and quad at the same time\n");
2434 return -EINVAL;
2435 }
2436 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2437 */
2438 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2439 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2440 return -EINVAL;
2441 /* help drivers fail *cleanly* when they need options
2442 * that aren't supported with their current master
2443 */
2444 bad_bits = spi->mode & ~spi->master->mode_bits;
2445 ugly_bits = bad_bits &
2446 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2447 if (ugly_bits) {
2448 dev_warn(&spi->dev,
2449 "setup: ignoring unsupported mode bits %x\n",
2450 ugly_bits);
2451 spi->mode &= ~ugly_bits;
2452 bad_bits &= ~ugly_bits;
2453 }
2454 if (bad_bits) {
2455 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
2456 bad_bits);
2457 return -EINVAL;
2458 }
2459
2460 if (!spi->bits_per_word)
2461 spi->bits_per_word = 8;
2462
2463 status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2464 if (status)
2465 return status;
2466
2467 if (!spi->max_speed_hz)
2468 spi->max_speed_hz = spi->master->max_speed_hz;
2469
2470 if (spi->master->setup)
2471 status = spi->master->setup(spi);
2472
2473 spi_set_cs(spi, false);
2474
2475 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2476 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2477 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2478 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2479 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2480 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2481 spi->bits_per_word, spi->max_speed_hz,
2482 status);
2483
2484 return status;
2485}
2486EXPORT_SYMBOL_GPL(spi_setup);
2487
2488static int __spi_validate(struct spi_device *spi, struct spi_message *message)
2489{
2490 struct spi_master *master = spi->master;
2491 struct spi_transfer *xfer;
2492 int w_size;
2493
2494 if (list_empty(&message->transfers))
2495 return -EINVAL;
2496
2497 /* Half-duplex links include original MicroWire, and ones with
2498 * only one data pin like SPI_3WIRE (switches direction) or where
2499 * either MOSI or MISO is missing. They can also be caused by
2500 * software limitations.
2501 */
2502 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2503 || (spi->mode & SPI_3WIRE)) {
2504 unsigned flags = master->flags;
2505
2506 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2507 if (xfer->rx_buf && xfer->tx_buf)
2508 return -EINVAL;
2509 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2510 return -EINVAL;
2511 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2512 return -EINVAL;
2513 }
2514 }
2515
2516 /**
2517 * Set transfer bits_per_word and max speed as spi device default if
2518 * it is not set for this transfer.
2519 * Set transfer tx_nbits and rx_nbits as single transfer default
2520 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2521 */
2522 message->frame_length = 0;
2523 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2524 message->frame_length += xfer->len;
2525 if (!xfer->bits_per_word)
2526 xfer->bits_per_word = spi->bits_per_word;
2527
2528 if (!xfer->speed_hz)
2529 xfer->speed_hz = spi->max_speed_hz;
2530 if (!xfer->speed_hz)
2531 xfer->speed_hz = master->max_speed_hz;
2532
2533 if (master->max_speed_hz &&
2534 xfer->speed_hz > master->max_speed_hz)
2535 xfer->speed_hz = master->max_speed_hz;
2536
2537 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2538 return -EINVAL;
2539
2540 /*
2541 * SPI transfer length should be multiple of SPI word size
2542 * where SPI word size should be power-of-two multiple
2543 */
2544 if (xfer->bits_per_word <= 8)
2545 w_size = 1;
2546 else if (xfer->bits_per_word <= 16)
2547 w_size = 2;
2548 else
2549 w_size = 4;
2550
2551 /* No partial transfers accepted */
2552 if (xfer->len % w_size)
2553 return -EINVAL;
2554
2555 if (xfer->speed_hz && master->min_speed_hz &&
2556 xfer->speed_hz < master->min_speed_hz)
2557 return -EINVAL;
2558
2559 if (xfer->tx_buf && !xfer->tx_nbits)
2560 xfer->tx_nbits = SPI_NBITS_SINGLE;
2561 if (xfer->rx_buf && !xfer->rx_nbits)
2562 xfer->rx_nbits = SPI_NBITS_SINGLE;
2563 /* check transfer tx/rx_nbits:
2564 * 1. check the value matches one of single, dual and quad
2565 * 2. check tx/rx_nbits match the mode in spi_device
2566 */
2567 if (xfer->tx_buf) {
2568 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2569 xfer->tx_nbits != SPI_NBITS_DUAL &&
2570 xfer->tx_nbits != SPI_NBITS_QUAD)
2571 return -EINVAL;
2572 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2573 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2574 return -EINVAL;
2575 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2576 !(spi->mode & SPI_TX_QUAD))
2577 return -EINVAL;
2578 }
2579 /* check transfer rx_nbits */
2580 if (xfer->rx_buf) {
2581 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2582 xfer->rx_nbits != SPI_NBITS_DUAL &&
2583 xfer->rx_nbits != SPI_NBITS_QUAD)
2584 return -EINVAL;
2585 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2586 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2587 return -EINVAL;
2588 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2589 !(spi->mode & SPI_RX_QUAD))
2590 return -EINVAL;
2591 }
2592 }
2593
2594 message->status = -EINPROGRESS;
2595
2596 return 0;
2597}
2598
2599static int __spi_async(struct spi_device *spi, struct spi_message *message)
2600{
2601 struct spi_master *master = spi->master;
2602
2603 message->spi = spi;
2604
2605 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2606 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2607
2608 trace_spi_message_submit(message);
2609
2610 return master->transfer(spi, message);
2611}
2612
2613/**
2614 * spi_async - asynchronous SPI transfer
2615 * @spi: device with which data will be exchanged
2616 * @message: describes the data transfers, including completion callback
2617 * Context: any (irqs may be blocked, etc)
2618 *
2619 * This call may be used in_irq and other contexts which can't sleep,
2620 * as well as from task contexts which can sleep.
2621 *
2622 * The completion callback is invoked in a context which can't sleep.
2623 * Before that invocation, the value of message->status is undefined.
2624 * When the callback is issued, message->status holds either zero (to
2625 * indicate complete success) or a negative error code. After that
2626 * callback returns, the driver which issued the transfer request may
2627 * deallocate the associated memory; it's no longer in use by any SPI
2628 * core or controller driver code.
2629 *
2630 * Note that although all messages to a spi_device are handled in
2631 * FIFO order, messages may go to different devices in other orders.
2632 * Some device might be higher priority, or have various "hard" access
2633 * time requirements, for example.
2634 *
2635 * On detection of any fault during the transfer, processing of
2636 * the entire message is aborted, and the device is deselected.
2637 * Until returning from the associated message completion callback,
2638 * no other spi_message queued to that device will be processed.
2639 * (This rule applies equally to all the synchronous transfer calls,
2640 * which are wrappers around this core asynchronous primitive.)
2641 *
2642 * Return: zero on success, else a negative error code.
2643 */
2644int spi_async(struct spi_device *spi, struct spi_message *message)
2645{
2646 struct spi_master *master = spi->master;
2647 int ret;
2648 unsigned long flags;
2649
2650 ret = __spi_validate(spi, message);
2651 if (ret != 0)
2652 return ret;
2653
2654 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2655
2656 if (master->bus_lock_flag)
2657 ret = -EBUSY;
2658 else
2659 ret = __spi_async(spi, message);
2660
2661 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2662
2663 return ret;
2664}
2665EXPORT_SYMBOL_GPL(spi_async);
2666
2667/**
2668 * spi_async_locked - version of spi_async with exclusive bus usage
2669 * @spi: device with which data will be exchanged
2670 * @message: describes the data transfers, including completion callback
2671 * Context: any (irqs may be blocked, etc)
2672 *
2673 * This call may be used in_irq and other contexts which can't sleep,
2674 * as well as from task contexts which can sleep.
2675 *
2676 * The completion callback is invoked in a context which can't sleep.
2677 * Before that invocation, the value of message->status is undefined.
2678 * When the callback is issued, message->status holds either zero (to
2679 * indicate complete success) or a negative error code. After that
2680 * callback returns, the driver which issued the transfer request may
2681 * deallocate the associated memory; it's no longer in use by any SPI
2682 * core or controller driver code.
2683 *
2684 * Note that although all messages to a spi_device are handled in
2685 * FIFO order, messages may go to different devices in other orders.
2686 * Some device might be higher priority, or have various "hard" access
2687 * time requirements, for example.
2688 *
2689 * On detection of any fault during the transfer, processing of
2690 * the entire message is aborted, and the device is deselected.
2691 * Until returning from the associated message completion callback,
2692 * no other spi_message queued to that device will be processed.
2693 * (This rule applies equally to all the synchronous transfer calls,
2694 * which are wrappers around this core asynchronous primitive.)
2695 *
2696 * Return: zero on success, else a negative error code.
2697 */
2698int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2699{
2700 struct spi_master *master = spi->master;
2701 int ret;
2702 unsigned long flags;
2703
2704 ret = __spi_validate(spi, message);
2705 if (ret != 0)
2706 return ret;
2707
2708 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2709
2710 ret = __spi_async(spi, message);
2711
2712 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2713
2714 return ret;
2715
2716}
2717EXPORT_SYMBOL_GPL(spi_async_locked);
2718
2719
2720int spi_flash_read(struct spi_device *spi,
2721 struct spi_flash_read_message *msg)
2722
2723{
2724 struct spi_master *master = spi->master;
2725 int ret;
2726
2727 if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2728 msg->addr_nbits == SPI_NBITS_DUAL) &&
2729 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2730 return -EINVAL;
2731 if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2732 msg->addr_nbits == SPI_NBITS_QUAD) &&
2733 !(spi->mode & SPI_TX_QUAD))
2734 return -EINVAL;
2735 if (msg->data_nbits == SPI_NBITS_DUAL &&
2736 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2737 return -EINVAL;
2738 if (msg->data_nbits == SPI_NBITS_QUAD &&
2739 !(spi->mode & SPI_RX_QUAD))
2740 return -EINVAL;
2741
2742 if (master->auto_runtime_pm) {
2743 ret = pm_runtime_get_sync(master->dev.parent);
2744 if (ret < 0) {
2745 dev_err(&master->dev, "Failed to power device: %d\n",
2746 ret);
2747 return ret;
2748 }
2749 }
2750 mutex_lock(&master->bus_lock_mutex);
2751 ret = master->spi_flash_read(spi, msg);
2752 mutex_unlock(&master->bus_lock_mutex);
2753 if (master->auto_runtime_pm)
2754 pm_runtime_put(master->dev.parent);
2755
2756 return ret;
2757}
2758EXPORT_SYMBOL_GPL(spi_flash_read);
2759
2760/*-------------------------------------------------------------------------*/
2761
2762/* Utility methods for SPI master protocol drivers, layered on
2763 * top of the core. Some other utility methods are defined as
2764 * inline functions.
2765 */
2766
2767static void spi_complete(void *arg)
2768{
2769 complete(arg);
2770}
2771
2772static int __spi_sync(struct spi_device *spi, struct spi_message *message,
2773 int bus_locked)
2774{
2775 DECLARE_COMPLETION_ONSTACK(done);
2776 int status;
2777 struct spi_master *master = spi->master;
2778 unsigned long flags;
2779
2780 status = __spi_validate(spi, message);
2781 if (status != 0)
2782 return status;
2783
2784 message->complete = spi_complete;
2785 message->context = &done;
2786 message->spi = spi;
2787
2788 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2789 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2790
2791 if (!bus_locked)
2792 mutex_lock(&master->bus_lock_mutex);
2793
2794 /* If we're not using the legacy transfer method then we will
2795 * try to transfer in the calling context so special case.
2796 * This code would be less tricky if we could remove the
2797 * support for driver implemented message queues.
2798 */
2799 if (master->transfer == spi_queued_transfer) {
2800 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2801
2802 trace_spi_message_submit(message);
2803
2804 status = __spi_queued_transfer(spi, message, false);
2805
2806 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2807 } else {
2808 status = spi_async_locked(spi, message);
2809 }
2810
2811 if (!bus_locked)
2812 mutex_unlock(&master->bus_lock_mutex);
2813
2814 if (status == 0) {
2815 /* Push out the messages in the calling context if we
2816 * can.
2817 */
2818 if (master->transfer == spi_queued_transfer) {
2819 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2820 spi_sync_immediate);
2821 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
2822 spi_sync_immediate);
2823 __spi_pump_messages(master, false, bus_locked);
2824 }
2825
2826 wait_for_completion(&done);
2827 status = message->status;
2828 }
2829 message->context = NULL;
2830 return status;
2831}
2832
2833/**
2834 * spi_sync - blocking/synchronous SPI data transfers
2835 * @spi: device with which data will be exchanged
2836 * @message: describes the data transfers
2837 * Context: can sleep
2838 *
2839 * This call may only be used from a context that may sleep. The sleep
2840 * is non-interruptible, and has no timeout. Low-overhead controller
2841 * drivers may DMA directly into and out of the message buffers.
2842 *
2843 * Note that the SPI device's chip select is active during the message,
2844 * and then is normally disabled between messages. Drivers for some
2845 * frequently-used devices may want to minimize costs of selecting a chip,
2846 * by leaving it selected in anticipation that the next message will go
2847 * to the same chip. (That may increase power usage.)
2848 *
2849 * Also, the caller is guaranteeing that the memory associated with the
2850 * message will not be freed before this call returns.
2851 *
2852 * Return: zero on success, else a negative error code.
2853 */
2854int spi_sync(struct spi_device *spi, struct spi_message *message)
2855{
2856 return __spi_sync(spi, message, spi->master->bus_lock_flag);
2857}
2858EXPORT_SYMBOL_GPL(spi_sync);
2859
2860/**
2861 * spi_sync_locked - version of spi_sync with exclusive bus usage
2862 * @spi: device with which data will be exchanged
2863 * @message: describes the data transfers
2864 * Context: can sleep
2865 *
2866 * This call may only be used from a context that may sleep. The sleep
2867 * is non-interruptible, and has no timeout. Low-overhead controller
2868 * drivers may DMA directly into and out of the message buffers.
2869 *
2870 * This call should be used by drivers that require exclusive access to the
2871 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
2872 * be released by a spi_bus_unlock call when the exclusive access is over.
2873 *
2874 * Return: zero on success, else a negative error code.
2875 */
2876int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2877{
2878 return __spi_sync(spi, message, 1);
2879}
2880EXPORT_SYMBOL_GPL(spi_sync_locked);
2881
2882/**
2883 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2884 * @master: SPI bus master that should be locked for exclusive bus access
2885 * Context: can sleep
2886 *
2887 * This call may only be used from a context that may sleep. The sleep
2888 * is non-interruptible, and has no timeout.
2889 *
2890 * This call should be used by drivers that require exclusive access to the
2891 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2892 * exclusive access is over. Data transfer must be done by spi_sync_locked
2893 * and spi_async_locked calls when the SPI bus lock is held.
2894 *
2895 * Return: always zero.
2896 */
2897int spi_bus_lock(struct spi_master *master)
2898{
2899 unsigned long flags;
2900
2901 mutex_lock(&master->bus_lock_mutex);
2902
2903 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2904 master->bus_lock_flag = 1;
2905 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2906
2907 /* mutex remains locked until spi_bus_unlock is called */
2908
2909 return 0;
2910}
2911EXPORT_SYMBOL_GPL(spi_bus_lock);
2912
2913/**
2914 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2915 * @master: SPI bus master that was locked for exclusive bus access
2916 * Context: can sleep
2917 *
2918 * This call may only be used from a context that may sleep. The sleep
2919 * is non-interruptible, and has no timeout.
2920 *
2921 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2922 * call.
2923 *
2924 * Return: always zero.
2925 */
2926int spi_bus_unlock(struct spi_master *master)
2927{
2928 master->bus_lock_flag = 0;
2929
2930 mutex_unlock(&master->bus_lock_mutex);
2931
2932 return 0;
2933}
2934EXPORT_SYMBOL_GPL(spi_bus_unlock);
2935
2936/* portable code must never pass more than 32 bytes */
2937#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
2938
2939static u8 *buf;
2940
2941/**
2942 * spi_write_then_read - SPI synchronous write followed by read
2943 * @spi: device with which data will be exchanged
2944 * @txbuf: data to be written (need not be dma-safe)
2945 * @n_tx: size of txbuf, in bytes
2946 * @rxbuf: buffer into which data will be read (need not be dma-safe)
2947 * @n_rx: size of rxbuf, in bytes
2948 * Context: can sleep
2949 *
2950 * This performs a half duplex MicroWire style transaction with the
2951 * device, sending txbuf and then reading rxbuf. The return value
2952 * is zero for success, else a negative errno status code.
2953 * This call may only be used from a context that may sleep.
2954 *
2955 * Parameters to this routine are always copied using a small buffer;
2956 * portable code should never use this for more than 32 bytes.
2957 * Performance-sensitive or bulk transfer code should instead use
2958 * spi_{async,sync}() calls with dma-safe buffers.
2959 *
2960 * Return: zero on success, else a negative error code.
2961 */
2962int spi_write_then_read(struct spi_device *spi,
2963 const void *txbuf, unsigned n_tx,
2964 void *rxbuf, unsigned n_rx)
2965{
2966 static DEFINE_MUTEX(lock);
2967
2968 int status;
2969 struct spi_message message;
2970 struct spi_transfer x[2];
2971 u8 *local_buf;
2972
2973 /* Use preallocated DMA-safe buffer if we can. We can't avoid
2974 * copying here, (as a pure convenience thing), but we can
2975 * keep heap costs out of the hot path unless someone else is
2976 * using the pre-allocated buffer or the transfer is too large.
2977 */
2978 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
2979 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
2980 GFP_KERNEL | GFP_DMA);
2981 if (!local_buf)
2982 return -ENOMEM;
2983 } else {
2984 local_buf = buf;
2985 }
2986
2987 spi_message_init(&message);
2988 memset(x, 0, sizeof(x));
2989 if (n_tx) {
2990 x[0].len = n_tx;
2991 spi_message_add_tail(&x[0], &message);
2992 }
2993 if (n_rx) {
2994 x[1].len = n_rx;
2995 spi_message_add_tail(&x[1], &message);
2996 }
2997
2998 memcpy(local_buf, txbuf, n_tx);
2999 x[0].tx_buf = local_buf;
3000 x[1].rx_buf = local_buf + n_tx;
3001
3002 /* do the i/o */
3003 status = spi_sync(spi, &message);
3004 if (status == 0)
3005 memcpy(rxbuf, x[1].rx_buf, n_rx);
3006
3007 if (x[0].tx_buf == buf)
3008 mutex_unlock(&lock);
3009 else
3010 kfree(local_buf);
3011
3012 return status;
3013}
3014EXPORT_SYMBOL_GPL(spi_write_then_read);
3015
3016/*-------------------------------------------------------------------------*/
3017
3018#if IS_ENABLED(CONFIG_OF_DYNAMIC)
3019static int __spi_of_device_match(struct device *dev, void *data)
3020{
3021 return dev->of_node == data;
3022}
3023
3024/* must call put_device() when done with returned spi_device device */
3025static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3026{
3027 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3028 __spi_of_device_match);
3029 return dev ? to_spi_device(dev) : NULL;
3030}
3031
3032static int __spi_of_master_match(struct device *dev, const void *data)
3033{
3034 return dev->of_node == data;
3035}
3036
3037/* the spi masters are not using spi_bus, so we find it with another way */
3038static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3039{
3040 struct device *dev;
3041
3042 dev = class_find_device(&spi_master_class, NULL, node,
3043 __spi_of_master_match);
3044 if (!dev)
3045 return NULL;
3046
3047 /* reference got in class_find_device */
3048 return container_of(dev, struct spi_master, dev);
3049}
3050
3051static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3052 void *arg)
3053{
3054 struct of_reconfig_data *rd = arg;
3055 struct spi_master *master;
3056 struct spi_device *spi;
3057
3058 switch (of_reconfig_get_state_change(action, arg)) {
3059 case OF_RECONFIG_CHANGE_ADD:
3060 master = of_find_spi_master_by_node(rd->dn->parent);
3061 if (master == NULL)
3062 return NOTIFY_OK; /* not for us */
3063
3064 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3065 put_device(&master->dev);
3066 return NOTIFY_OK;
3067 }
3068
3069 spi = of_register_spi_device(master, rd->dn);
3070 put_device(&master->dev);
3071
3072 if (IS_ERR(spi)) {
3073 pr_err("%s: failed to create for '%s'\n",
3074 __func__, rd->dn->full_name);
3075 return notifier_from_errno(PTR_ERR(spi));
3076 }
3077 break;
3078
3079 case OF_RECONFIG_CHANGE_REMOVE:
3080 /* already depopulated? */
3081 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3082 return NOTIFY_OK;
3083
3084 /* find our device by node */
3085 spi = of_find_spi_device_by_node(rd->dn);
3086 if (spi == NULL)
3087 return NOTIFY_OK; /* no? not meant for us */
3088
3089 /* unregister takes one ref away */
3090 spi_unregister_device(spi);
3091
3092 /* and put the reference of the find */
3093 put_device(&spi->dev);
3094 break;
3095 }
3096
3097 return NOTIFY_OK;
3098}
3099
3100static struct notifier_block spi_of_notifier = {
3101 .notifier_call = of_spi_notify,
3102};
3103#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3104extern struct notifier_block spi_of_notifier;
3105#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3106
3107static int __init spi_init(void)
3108{
3109 int status;
3110
3111 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
3112 if (!buf) {
3113 status = -ENOMEM;
3114 goto err0;
3115 }
3116
3117 status = bus_register(&spi_bus_type);
3118 if (status < 0)
3119 goto err1;
3120
3121 status = class_register(&spi_master_class);
3122 if (status < 0)
3123 goto err2;
3124
3125 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
3126 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3127
3128 return 0;
3129
3130err2:
3131 bus_unregister(&spi_bus_type);
3132err1:
3133 kfree(buf);
3134 buf = NULL;
3135err0:
3136 return status;
3137}
3138
3139/* board_info is normally registered in arch_initcall(),
3140 * but even essential drivers wait till later
3141 *
3142 * REVISIT only boardinfo really needs static linking. the rest (device and
3143 * driver registration) _could_ be dynamically linked (modular) ... costs
3144 * include needing to have boardinfo data structures be much more public.
3145 */
3146postcore_initcall(spi_init);
3147