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1/*
2 * SPI init/core code
3 *
4 * Copyright (C) 2005 David Brownell
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21#include <linux/kernel.h>
22#include <linux/device.h>
23#include <linux/init.h>
24#include <linux/cache.h>
25#include <linux/mutex.h>
26#include <linux/of_device.h>
27#include <linux/slab.h>
28#include <linux/mod_devicetable.h>
29#include <linux/spi/spi.h>
30#include <linux/of_spi.h>
31#include <linux/pm_runtime.h>
32
33static void spidev_release(struct device *dev)
34{
35 struct spi_device *spi = to_spi_device(dev);
36
37 /* spi masters may cleanup for released devices */
38 if (spi->master->cleanup)
39 spi->master->cleanup(spi);
40
41 spi_master_put(spi->master);
42 kfree(spi);
43}
44
45static ssize_t
46modalias_show(struct device *dev, struct device_attribute *a, char *buf)
47{
48 const struct spi_device *spi = to_spi_device(dev);
49
50 return sprintf(buf, "%s\n", spi->modalias);
51}
52
53static struct device_attribute spi_dev_attrs[] = {
54 __ATTR_RO(modalias),
55 __ATTR_NULL,
56};
57
58/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
59 * and the sysfs version makes coldplug work too.
60 */
61
62static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
63 const struct spi_device *sdev)
64{
65 while (id->name[0]) {
66 if (!strcmp(sdev->modalias, id->name))
67 return id;
68 id++;
69 }
70 return NULL;
71}
72
73const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
74{
75 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
76
77 return spi_match_id(sdrv->id_table, sdev);
78}
79EXPORT_SYMBOL_GPL(spi_get_device_id);
80
81static int spi_match_device(struct device *dev, struct device_driver *drv)
82{
83 const struct spi_device *spi = to_spi_device(dev);
84 const struct spi_driver *sdrv = to_spi_driver(drv);
85
86 /* Attempt an OF style match */
87 if (of_driver_match_device(dev, drv))
88 return 1;
89
90 if (sdrv->id_table)
91 return !!spi_match_id(sdrv->id_table, spi);
92
93 return strcmp(spi->modalias, drv->name) == 0;
94}
95
96static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
97{
98 const struct spi_device *spi = to_spi_device(dev);
99
100 add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
101 return 0;
102}
103
104#ifdef CONFIG_PM_SLEEP
105static int spi_legacy_suspend(struct device *dev, pm_message_t message)
106{
107 int value = 0;
108 struct spi_driver *drv = to_spi_driver(dev->driver);
109
110 /* suspend will stop irqs and dma; no more i/o */
111 if (drv) {
112 if (drv->suspend)
113 value = drv->suspend(to_spi_device(dev), message);
114 else
115 dev_dbg(dev, "... can't suspend\n");
116 }
117 return value;
118}
119
120static int spi_legacy_resume(struct device *dev)
121{
122 int value = 0;
123 struct spi_driver *drv = to_spi_driver(dev->driver);
124
125 /* resume may restart the i/o queue */
126 if (drv) {
127 if (drv->resume)
128 value = drv->resume(to_spi_device(dev));
129 else
130 dev_dbg(dev, "... can't resume\n");
131 }
132 return value;
133}
134
135static int spi_pm_suspend(struct device *dev)
136{
137 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
138
139 if (pm)
140 return pm_generic_suspend(dev);
141 else
142 return spi_legacy_suspend(dev, PMSG_SUSPEND);
143}
144
145static int spi_pm_resume(struct device *dev)
146{
147 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
148
149 if (pm)
150 return pm_generic_resume(dev);
151 else
152 return spi_legacy_resume(dev);
153}
154
155static int spi_pm_freeze(struct device *dev)
156{
157 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
158
159 if (pm)
160 return pm_generic_freeze(dev);
161 else
162 return spi_legacy_suspend(dev, PMSG_FREEZE);
163}
164
165static int spi_pm_thaw(struct device *dev)
166{
167 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
168
169 if (pm)
170 return pm_generic_thaw(dev);
171 else
172 return spi_legacy_resume(dev);
173}
174
175static int spi_pm_poweroff(struct device *dev)
176{
177 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
178
179 if (pm)
180 return pm_generic_poweroff(dev);
181 else
182 return spi_legacy_suspend(dev, PMSG_HIBERNATE);
183}
184
185static int spi_pm_restore(struct device *dev)
186{
187 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
188
189 if (pm)
190 return pm_generic_restore(dev);
191 else
192 return spi_legacy_resume(dev);
193}
194#else
195#define spi_pm_suspend NULL
196#define spi_pm_resume NULL
197#define spi_pm_freeze NULL
198#define spi_pm_thaw NULL
199#define spi_pm_poweroff NULL
200#define spi_pm_restore NULL
201#endif
202
203static const struct dev_pm_ops spi_pm = {
204 .suspend = spi_pm_suspend,
205 .resume = spi_pm_resume,
206 .freeze = spi_pm_freeze,
207 .thaw = spi_pm_thaw,
208 .poweroff = spi_pm_poweroff,
209 .restore = spi_pm_restore,
210 SET_RUNTIME_PM_OPS(
211 pm_generic_runtime_suspend,
212 pm_generic_runtime_resume,
213 pm_generic_runtime_idle
214 )
215};
216
217struct bus_type spi_bus_type = {
218 .name = "spi",
219 .dev_attrs = spi_dev_attrs,
220 .match = spi_match_device,
221 .uevent = spi_uevent,
222 .pm = &spi_pm,
223};
224EXPORT_SYMBOL_GPL(spi_bus_type);
225
226
227static int spi_drv_probe(struct device *dev)
228{
229 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
230
231 return sdrv->probe(to_spi_device(dev));
232}
233
234static int spi_drv_remove(struct device *dev)
235{
236 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
237
238 return sdrv->remove(to_spi_device(dev));
239}
240
241static void spi_drv_shutdown(struct device *dev)
242{
243 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
244
245 sdrv->shutdown(to_spi_device(dev));
246}
247
248/**
249 * spi_register_driver - register a SPI driver
250 * @sdrv: the driver to register
251 * Context: can sleep
252 */
253int spi_register_driver(struct spi_driver *sdrv)
254{
255 sdrv->driver.bus = &spi_bus_type;
256 if (sdrv->probe)
257 sdrv->driver.probe = spi_drv_probe;
258 if (sdrv->remove)
259 sdrv->driver.remove = spi_drv_remove;
260 if (sdrv->shutdown)
261 sdrv->driver.shutdown = spi_drv_shutdown;
262 return driver_register(&sdrv->driver);
263}
264EXPORT_SYMBOL_GPL(spi_register_driver);
265
266/*-------------------------------------------------------------------------*/
267
268/* SPI devices should normally not be created by SPI device drivers; that
269 * would make them board-specific. Similarly with SPI master drivers.
270 * Device registration normally goes into like arch/.../mach.../board-YYY.c
271 * with other readonly (flashable) information about mainboard devices.
272 */
273
274struct boardinfo {
275 struct list_head list;
276 struct spi_board_info board_info;
277};
278
279static LIST_HEAD(board_list);
280static LIST_HEAD(spi_master_list);
281
282/*
283 * Used to protect add/del opertion for board_info list and
284 * spi_master list, and their matching process
285 */
286static DEFINE_MUTEX(board_lock);
287
288/**
289 * spi_alloc_device - Allocate a new SPI device
290 * @master: Controller to which device is connected
291 * Context: can sleep
292 *
293 * Allows a driver to allocate and initialize a spi_device without
294 * registering it immediately. This allows a driver to directly
295 * fill the spi_device with device parameters before calling
296 * spi_add_device() on it.
297 *
298 * Caller is responsible to call spi_add_device() on the returned
299 * spi_device structure to add it to the SPI master. If the caller
300 * needs to discard the spi_device without adding it, then it should
301 * call spi_dev_put() on it.
302 *
303 * Returns a pointer to the new device, or NULL.
304 */
305struct spi_device *spi_alloc_device(struct spi_master *master)
306{
307 struct spi_device *spi;
308 struct device *dev = master->dev.parent;
309
310 if (!spi_master_get(master))
311 return NULL;
312
313 spi = kzalloc(sizeof *spi, GFP_KERNEL);
314 if (!spi) {
315 dev_err(dev, "cannot alloc spi_device\n");
316 spi_master_put(master);
317 return NULL;
318 }
319
320 spi->master = master;
321 spi->dev.parent = dev;
322 spi->dev.bus = &spi_bus_type;
323 spi->dev.release = spidev_release;
324 device_initialize(&spi->dev);
325 return spi;
326}
327EXPORT_SYMBOL_GPL(spi_alloc_device);
328
329/**
330 * spi_add_device - Add spi_device allocated with spi_alloc_device
331 * @spi: spi_device to register
332 *
333 * Companion function to spi_alloc_device. Devices allocated with
334 * spi_alloc_device can be added onto the spi bus with this function.
335 *
336 * Returns 0 on success; negative errno on failure
337 */
338int spi_add_device(struct spi_device *spi)
339{
340 static DEFINE_MUTEX(spi_add_lock);
341 struct device *dev = spi->master->dev.parent;
342 struct device *d;
343 int status;
344
345 /* Chipselects are numbered 0..max; validate. */
346 if (spi->chip_select >= spi->master->num_chipselect) {
347 dev_err(dev, "cs%d >= max %d\n",
348 spi->chip_select,
349 spi->master->num_chipselect);
350 return -EINVAL;
351 }
352
353 /* Set the bus ID string */
354 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
355 spi->chip_select);
356
357
358 /* We need to make sure there's no other device with this
359 * chipselect **BEFORE** we call setup(), else we'll trash
360 * its configuration. Lock against concurrent add() calls.
361 */
362 mutex_lock(&spi_add_lock);
363
364 d = bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev));
365 if (d != NULL) {
366 dev_err(dev, "chipselect %d already in use\n",
367 spi->chip_select);
368 put_device(d);
369 status = -EBUSY;
370 goto done;
371 }
372
373 /* Drivers may modify this initial i/o setup, but will
374 * normally rely on the device being setup. Devices
375 * using SPI_CS_HIGH can't coexist well otherwise...
376 */
377 status = spi_setup(spi);
378 if (status < 0) {
379 dev_err(dev, "can't setup %s, status %d\n",
380 dev_name(&spi->dev), status);
381 goto done;
382 }
383
384 /* Device may be bound to an active driver when this returns */
385 status = device_add(&spi->dev);
386 if (status < 0)
387 dev_err(dev, "can't add %s, status %d\n",
388 dev_name(&spi->dev), status);
389 else
390 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
391
392done:
393 mutex_unlock(&spi_add_lock);
394 return status;
395}
396EXPORT_SYMBOL_GPL(spi_add_device);
397
398/**
399 * spi_new_device - instantiate one new SPI device
400 * @master: Controller to which device is connected
401 * @chip: Describes the SPI device
402 * Context: can sleep
403 *
404 * On typical mainboards, this is purely internal; and it's not needed
405 * after board init creates the hard-wired devices. Some development
406 * platforms may not be able to use spi_register_board_info though, and
407 * this is exported so that for example a USB or parport based adapter
408 * driver could add devices (which it would learn about out-of-band).
409 *
410 * Returns the new device, or NULL.
411 */
412struct spi_device *spi_new_device(struct spi_master *master,
413 struct spi_board_info *chip)
414{
415 struct spi_device *proxy;
416 int status;
417
418 /* NOTE: caller did any chip->bus_num checks necessary.
419 *
420 * Also, unless we change the return value convention to use
421 * error-or-pointer (not NULL-or-pointer), troubleshootability
422 * suggests syslogged diagnostics are best here (ugh).
423 */
424
425 proxy = spi_alloc_device(master);
426 if (!proxy)
427 return NULL;
428
429 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
430
431 proxy->chip_select = chip->chip_select;
432 proxy->max_speed_hz = chip->max_speed_hz;
433 proxy->mode = chip->mode;
434 proxy->irq = chip->irq;
435 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
436 proxy->dev.platform_data = (void *) chip->platform_data;
437 proxy->controller_data = chip->controller_data;
438 proxy->controller_state = NULL;
439
440 status = spi_add_device(proxy);
441 if (status < 0) {
442 spi_dev_put(proxy);
443 return NULL;
444 }
445
446 return proxy;
447}
448EXPORT_SYMBOL_GPL(spi_new_device);
449
450static void spi_match_master_to_boardinfo(struct spi_master *master,
451 struct spi_board_info *bi)
452{
453 struct spi_device *dev;
454
455 if (master->bus_num != bi->bus_num)
456 return;
457
458 dev = spi_new_device(master, bi);
459 if (!dev)
460 dev_err(master->dev.parent, "can't create new device for %s\n",
461 bi->modalias);
462}
463
464/**
465 * spi_register_board_info - register SPI devices for a given board
466 * @info: array of chip descriptors
467 * @n: how many descriptors are provided
468 * Context: can sleep
469 *
470 * Board-specific early init code calls this (probably during arch_initcall)
471 * with segments of the SPI device table. Any device nodes are created later,
472 * after the relevant parent SPI controller (bus_num) is defined. We keep
473 * this table of devices forever, so that reloading a controller driver will
474 * not make Linux forget about these hard-wired devices.
475 *
476 * Other code can also call this, e.g. a particular add-on board might provide
477 * SPI devices through its expansion connector, so code initializing that board
478 * would naturally declare its SPI devices.
479 *
480 * The board info passed can safely be __initdata ... but be careful of
481 * any embedded pointers (platform_data, etc), they're copied as-is.
482 */
483int __init
484spi_register_board_info(struct spi_board_info const *info, unsigned n)
485{
486 struct boardinfo *bi;
487 int i;
488
489 bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
490 if (!bi)
491 return -ENOMEM;
492
493 for (i = 0; i < n; i++, bi++, info++) {
494 struct spi_master *master;
495
496 memcpy(&bi->board_info, info, sizeof(*info));
497 mutex_lock(&board_lock);
498 list_add_tail(&bi->list, &board_list);
499 list_for_each_entry(master, &spi_master_list, list)
500 spi_match_master_to_boardinfo(master, &bi->board_info);
501 mutex_unlock(&board_lock);
502 }
503
504 return 0;
505}
506
507/*-------------------------------------------------------------------------*/
508
509static void spi_master_release(struct device *dev)
510{
511 struct spi_master *master;
512
513 master = container_of(dev, struct spi_master, dev);
514 kfree(master);
515}
516
517static struct class spi_master_class = {
518 .name = "spi_master",
519 .owner = THIS_MODULE,
520 .dev_release = spi_master_release,
521};
522
523
524/**
525 * spi_alloc_master - allocate SPI master controller
526 * @dev: the controller, possibly using the platform_bus
527 * @size: how much zeroed driver-private data to allocate; the pointer to this
528 * memory is in the driver_data field of the returned device,
529 * accessible with spi_master_get_devdata().
530 * Context: can sleep
531 *
532 * This call is used only by SPI master controller drivers, which are the
533 * only ones directly touching chip registers. It's how they allocate
534 * an spi_master structure, prior to calling spi_register_master().
535 *
536 * This must be called from context that can sleep. It returns the SPI
537 * master structure on success, else NULL.
538 *
539 * The caller is responsible for assigning the bus number and initializing
540 * the master's methods before calling spi_register_master(); and (after errors
541 * adding the device) calling spi_master_put() to prevent a memory leak.
542 */
543struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
544{
545 struct spi_master *master;
546
547 if (!dev)
548 return NULL;
549
550 master = kzalloc(size + sizeof *master, GFP_KERNEL);
551 if (!master)
552 return NULL;
553
554 device_initialize(&master->dev);
555 master->dev.class = &spi_master_class;
556 master->dev.parent = get_device(dev);
557 spi_master_set_devdata(master, &master[1]);
558
559 return master;
560}
561EXPORT_SYMBOL_GPL(spi_alloc_master);
562
563/**
564 * spi_register_master - register SPI master controller
565 * @master: initialized master, originally from spi_alloc_master()
566 * Context: can sleep
567 *
568 * SPI master controllers connect to their drivers using some non-SPI bus,
569 * such as the platform bus. The final stage of probe() in that code
570 * includes calling spi_register_master() to hook up to this SPI bus glue.
571 *
572 * SPI controllers use board specific (often SOC specific) bus numbers,
573 * and board-specific addressing for SPI devices combines those numbers
574 * with chip select numbers. Since SPI does not directly support dynamic
575 * device identification, boards need configuration tables telling which
576 * chip is at which address.
577 *
578 * This must be called from context that can sleep. It returns zero on
579 * success, else a negative error code (dropping the master's refcount).
580 * After a successful return, the caller is responsible for calling
581 * spi_unregister_master().
582 */
583int spi_register_master(struct spi_master *master)
584{
585 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
586 struct device *dev = master->dev.parent;
587 struct boardinfo *bi;
588 int status = -ENODEV;
589 int dynamic = 0;
590
591 if (!dev)
592 return -ENODEV;
593
594 /* even if it's just one always-selected device, there must
595 * be at least one chipselect
596 */
597 if (master->num_chipselect == 0)
598 return -EINVAL;
599
600 /* convention: dynamically assigned bus IDs count down from the max */
601 if (master->bus_num < 0) {
602 /* FIXME switch to an IDR based scheme, something like
603 * I2C now uses, so we can't run out of "dynamic" IDs
604 */
605 master->bus_num = atomic_dec_return(&dyn_bus_id);
606 dynamic = 1;
607 }
608
609 spin_lock_init(&master->bus_lock_spinlock);
610 mutex_init(&master->bus_lock_mutex);
611 master->bus_lock_flag = 0;
612
613 /* register the device, then userspace will see it.
614 * registration fails if the bus ID is in use.
615 */
616 dev_set_name(&master->dev, "spi%u", master->bus_num);
617 status = device_add(&master->dev);
618 if (status < 0)
619 goto done;
620 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
621 dynamic ? " (dynamic)" : "");
622
623 mutex_lock(&board_lock);
624 list_add_tail(&master->list, &spi_master_list);
625 list_for_each_entry(bi, &board_list, list)
626 spi_match_master_to_boardinfo(master, &bi->board_info);
627 mutex_unlock(&board_lock);
628
629 status = 0;
630
631 /* Register devices from the device tree */
632 of_register_spi_devices(master);
633done:
634 return status;
635}
636EXPORT_SYMBOL_GPL(spi_register_master);
637
638
639static int __unregister(struct device *dev, void *null)
640{
641 spi_unregister_device(to_spi_device(dev));
642 return 0;
643}
644
645/**
646 * spi_unregister_master - unregister SPI master controller
647 * @master: the master being unregistered
648 * Context: can sleep
649 *
650 * This call is used only by SPI master controller drivers, which are the
651 * only ones directly touching chip registers.
652 *
653 * This must be called from context that can sleep.
654 */
655void spi_unregister_master(struct spi_master *master)
656{
657 int dummy;
658
659 mutex_lock(&board_lock);
660 list_del(&master->list);
661 mutex_unlock(&board_lock);
662
663 dummy = device_for_each_child(&master->dev, NULL, __unregister);
664 device_unregister(&master->dev);
665}
666EXPORT_SYMBOL_GPL(spi_unregister_master);
667
668static int __spi_master_match(struct device *dev, void *data)
669{
670 struct spi_master *m;
671 u16 *bus_num = data;
672
673 m = container_of(dev, struct spi_master, dev);
674 return m->bus_num == *bus_num;
675}
676
677/**
678 * spi_busnum_to_master - look up master associated with bus_num
679 * @bus_num: the master's bus number
680 * Context: can sleep
681 *
682 * This call may be used with devices that are registered after
683 * arch init time. It returns a refcounted pointer to the relevant
684 * spi_master (which the caller must release), or NULL if there is
685 * no such master registered.
686 */
687struct spi_master *spi_busnum_to_master(u16 bus_num)
688{
689 struct device *dev;
690 struct spi_master *master = NULL;
691
692 dev = class_find_device(&spi_master_class, NULL, &bus_num,
693 __spi_master_match);
694 if (dev)
695 master = container_of(dev, struct spi_master, dev);
696 /* reference got in class_find_device */
697 return master;
698}
699EXPORT_SYMBOL_GPL(spi_busnum_to_master);
700
701
702/*-------------------------------------------------------------------------*/
703
704/* Core methods for SPI master protocol drivers. Some of the
705 * other core methods are currently defined as inline functions.
706 */
707
708/**
709 * spi_setup - setup SPI mode and clock rate
710 * @spi: the device whose settings are being modified
711 * Context: can sleep, and no requests are queued to the device
712 *
713 * SPI protocol drivers may need to update the transfer mode if the
714 * device doesn't work with its default. They may likewise need
715 * to update clock rates or word sizes from initial values. This function
716 * changes those settings, and must be called from a context that can sleep.
717 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
718 * effect the next time the device is selected and data is transferred to
719 * or from it. When this function returns, the spi device is deselected.
720 *
721 * Note that this call will fail if the protocol driver specifies an option
722 * that the underlying controller or its driver does not support. For
723 * example, not all hardware supports wire transfers using nine bit words,
724 * LSB-first wire encoding, or active-high chipselects.
725 */
726int spi_setup(struct spi_device *spi)
727{
728 unsigned bad_bits;
729 int status;
730
731 /* help drivers fail *cleanly* when they need options
732 * that aren't supported with their current master
733 */
734 bad_bits = spi->mode & ~spi->master->mode_bits;
735 if (bad_bits) {
736 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
737 bad_bits);
738 return -EINVAL;
739 }
740
741 if (!spi->bits_per_word)
742 spi->bits_per_word = 8;
743
744 status = spi->master->setup(spi);
745
746 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s"
747 "%u bits/w, %u Hz max --> %d\n",
748 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
749 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
750 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
751 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
752 (spi->mode & SPI_LOOP) ? "loopback, " : "",
753 spi->bits_per_word, spi->max_speed_hz,
754 status);
755
756 return status;
757}
758EXPORT_SYMBOL_GPL(spi_setup);
759
760static int __spi_async(struct spi_device *spi, struct spi_message *message)
761{
762 struct spi_master *master = spi->master;
763
764 /* Half-duplex links include original MicroWire, and ones with
765 * only one data pin like SPI_3WIRE (switches direction) or where
766 * either MOSI or MISO is missing. They can also be caused by
767 * software limitations.
768 */
769 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
770 || (spi->mode & SPI_3WIRE)) {
771 struct spi_transfer *xfer;
772 unsigned flags = master->flags;
773
774 list_for_each_entry(xfer, &message->transfers, transfer_list) {
775 if (xfer->rx_buf && xfer->tx_buf)
776 return -EINVAL;
777 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
778 return -EINVAL;
779 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
780 return -EINVAL;
781 }
782 }
783
784 message->spi = spi;
785 message->status = -EINPROGRESS;
786 return master->transfer(spi, message);
787}
788
789/**
790 * spi_async - asynchronous SPI transfer
791 * @spi: device with which data will be exchanged
792 * @message: describes the data transfers, including completion callback
793 * Context: any (irqs may be blocked, etc)
794 *
795 * This call may be used in_irq and other contexts which can't sleep,
796 * as well as from task contexts which can sleep.
797 *
798 * The completion callback is invoked in a context which can't sleep.
799 * Before that invocation, the value of message->status is undefined.
800 * When the callback is issued, message->status holds either zero (to
801 * indicate complete success) or a negative error code. After that
802 * callback returns, the driver which issued the transfer request may
803 * deallocate the associated memory; it's no longer in use by any SPI
804 * core or controller driver code.
805 *
806 * Note that although all messages to a spi_device are handled in
807 * FIFO order, messages may go to different devices in other orders.
808 * Some device might be higher priority, or have various "hard" access
809 * time requirements, for example.
810 *
811 * On detection of any fault during the transfer, processing of
812 * the entire message is aborted, and the device is deselected.
813 * Until returning from the associated message completion callback,
814 * no other spi_message queued to that device will be processed.
815 * (This rule applies equally to all the synchronous transfer calls,
816 * which are wrappers around this core asynchronous primitive.)
817 */
818int spi_async(struct spi_device *spi, struct spi_message *message)
819{
820 struct spi_master *master = spi->master;
821 int ret;
822 unsigned long flags;
823
824 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
825
826 if (master->bus_lock_flag)
827 ret = -EBUSY;
828 else
829 ret = __spi_async(spi, message);
830
831 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
832
833 return ret;
834}
835EXPORT_SYMBOL_GPL(spi_async);
836
837/**
838 * spi_async_locked - version of spi_async with exclusive bus usage
839 * @spi: device with which data will be exchanged
840 * @message: describes the data transfers, including completion callback
841 * Context: any (irqs may be blocked, etc)
842 *
843 * This call may be used in_irq and other contexts which can't sleep,
844 * as well as from task contexts which can sleep.
845 *
846 * The completion callback is invoked in a context which can't sleep.
847 * Before that invocation, the value of message->status is undefined.
848 * When the callback is issued, message->status holds either zero (to
849 * indicate complete success) or a negative error code. After that
850 * callback returns, the driver which issued the transfer request may
851 * deallocate the associated memory; it's no longer in use by any SPI
852 * core or controller driver code.
853 *
854 * Note that although all messages to a spi_device are handled in
855 * FIFO order, messages may go to different devices in other orders.
856 * Some device might be higher priority, or have various "hard" access
857 * time requirements, for example.
858 *
859 * On detection of any fault during the transfer, processing of
860 * the entire message is aborted, and the device is deselected.
861 * Until returning from the associated message completion callback,
862 * no other spi_message queued to that device will be processed.
863 * (This rule applies equally to all the synchronous transfer calls,
864 * which are wrappers around this core asynchronous primitive.)
865 */
866int spi_async_locked(struct spi_device *spi, struct spi_message *message)
867{
868 struct spi_master *master = spi->master;
869 int ret;
870 unsigned long flags;
871
872 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
873
874 ret = __spi_async(spi, message);
875
876 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
877
878 return ret;
879
880}
881EXPORT_SYMBOL_GPL(spi_async_locked);
882
883
884/*-------------------------------------------------------------------------*/
885
886/* Utility methods for SPI master protocol drivers, layered on
887 * top of the core. Some other utility methods are defined as
888 * inline functions.
889 */
890
891static void spi_complete(void *arg)
892{
893 complete(arg);
894}
895
896static int __spi_sync(struct spi_device *spi, struct spi_message *message,
897 int bus_locked)
898{
899 DECLARE_COMPLETION_ONSTACK(done);
900 int status;
901 struct spi_master *master = spi->master;
902
903 message->complete = spi_complete;
904 message->context = &done;
905
906 if (!bus_locked)
907 mutex_lock(&master->bus_lock_mutex);
908
909 status = spi_async_locked(spi, message);
910
911 if (!bus_locked)
912 mutex_unlock(&master->bus_lock_mutex);
913
914 if (status == 0) {
915 wait_for_completion(&done);
916 status = message->status;
917 }
918 message->context = NULL;
919 return status;
920}
921
922/**
923 * spi_sync - blocking/synchronous SPI data transfers
924 * @spi: device with which data will be exchanged
925 * @message: describes the data transfers
926 * Context: can sleep
927 *
928 * This call may only be used from a context that may sleep. The sleep
929 * is non-interruptible, and has no timeout. Low-overhead controller
930 * drivers may DMA directly into and out of the message buffers.
931 *
932 * Note that the SPI device's chip select is active during the message,
933 * and then is normally disabled between messages. Drivers for some
934 * frequently-used devices may want to minimize costs of selecting a chip,
935 * by leaving it selected in anticipation that the next message will go
936 * to the same chip. (That may increase power usage.)
937 *
938 * Also, the caller is guaranteeing that the memory associated with the
939 * message will not be freed before this call returns.
940 *
941 * It returns zero on success, else a negative error code.
942 */
943int spi_sync(struct spi_device *spi, struct spi_message *message)
944{
945 return __spi_sync(spi, message, 0);
946}
947EXPORT_SYMBOL_GPL(spi_sync);
948
949/**
950 * spi_sync_locked - version of spi_sync with exclusive bus usage
951 * @spi: device with which data will be exchanged
952 * @message: describes the data transfers
953 * Context: can sleep
954 *
955 * This call may only be used from a context that may sleep. The sleep
956 * is non-interruptible, and has no timeout. Low-overhead controller
957 * drivers may DMA directly into and out of the message buffers.
958 *
959 * This call should be used by drivers that require exclusive access to the
960 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
961 * be released by a spi_bus_unlock call when the exclusive access is over.
962 *
963 * It returns zero on success, else a negative error code.
964 */
965int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
966{
967 return __spi_sync(spi, message, 1);
968}
969EXPORT_SYMBOL_GPL(spi_sync_locked);
970
971/**
972 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
973 * @master: SPI bus master that should be locked for exclusive bus access
974 * Context: can sleep
975 *
976 * This call may only be used from a context that may sleep. The sleep
977 * is non-interruptible, and has no timeout.
978 *
979 * This call should be used by drivers that require exclusive access to the
980 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
981 * exclusive access is over. Data transfer must be done by spi_sync_locked
982 * and spi_async_locked calls when the SPI bus lock is held.
983 *
984 * It returns zero on success, else a negative error code.
985 */
986int spi_bus_lock(struct spi_master *master)
987{
988 unsigned long flags;
989
990 mutex_lock(&master->bus_lock_mutex);
991
992 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
993 master->bus_lock_flag = 1;
994 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
995
996 /* mutex remains locked until spi_bus_unlock is called */
997
998 return 0;
999}
1000EXPORT_SYMBOL_GPL(spi_bus_lock);
1001
1002/**
1003 * spi_bus_unlock - release the lock for exclusive SPI bus usage
1004 * @master: SPI bus master that was locked for exclusive bus access
1005 * Context: can sleep
1006 *
1007 * This call may only be used from a context that may sleep. The sleep
1008 * is non-interruptible, and has no timeout.
1009 *
1010 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
1011 * call.
1012 *
1013 * It returns zero on success, else a negative error code.
1014 */
1015int spi_bus_unlock(struct spi_master *master)
1016{
1017 master->bus_lock_flag = 0;
1018
1019 mutex_unlock(&master->bus_lock_mutex);
1020
1021 return 0;
1022}
1023EXPORT_SYMBOL_GPL(spi_bus_unlock);
1024
1025/* portable code must never pass more than 32 bytes */
1026#define SPI_BUFSIZ max(32,SMP_CACHE_BYTES)
1027
1028static u8 *buf;
1029
1030/**
1031 * spi_write_then_read - SPI synchronous write followed by read
1032 * @spi: device with which data will be exchanged
1033 * @txbuf: data to be written (need not be dma-safe)
1034 * @n_tx: size of txbuf, in bytes
1035 * @rxbuf: buffer into which data will be read (need not be dma-safe)
1036 * @n_rx: size of rxbuf, in bytes
1037 * Context: can sleep
1038 *
1039 * This performs a half duplex MicroWire style transaction with the
1040 * device, sending txbuf and then reading rxbuf. The return value
1041 * is zero for success, else a negative errno status code.
1042 * This call may only be used from a context that may sleep.
1043 *
1044 * Parameters to this routine are always copied using a small buffer;
1045 * portable code should never use this for more than 32 bytes.
1046 * Performance-sensitive or bulk transfer code should instead use
1047 * spi_{async,sync}() calls with dma-safe buffers.
1048 */
1049int spi_write_then_read(struct spi_device *spi,
1050 const void *txbuf, unsigned n_tx,
1051 void *rxbuf, unsigned n_rx)
1052{
1053 static DEFINE_MUTEX(lock);
1054
1055 int status;
1056 struct spi_message message;
1057 struct spi_transfer x[2];
1058 u8 *local_buf;
1059
1060 /* Use preallocated DMA-safe buffer. We can't avoid copying here,
1061 * (as a pure convenience thing), but we can keep heap costs
1062 * out of the hot path ...
1063 */
1064 if ((n_tx + n_rx) > SPI_BUFSIZ)
1065 return -EINVAL;
1066
1067 spi_message_init(&message);
1068 memset(x, 0, sizeof x);
1069 if (n_tx) {
1070 x[0].len = n_tx;
1071 spi_message_add_tail(&x[0], &message);
1072 }
1073 if (n_rx) {
1074 x[1].len = n_rx;
1075 spi_message_add_tail(&x[1], &message);
1076 }
1077
1078 /* ... unless someone else is using the pre-allocated buffer */
1079 if (!mutex_trylock(&lock)) {
1080 local_buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
1081 if (!local_buf)
1082 return -ENOMEM;
1083 } else
1084 local_buf = buf;
1085
1086 memcpy(local_buf, txbuf, n_tx);
1087 x[0].tx_buf = local_buf;
1088 x[1].rx_buf = local_buf + n_tx;
1089
1090 /* do the i/o */
1091 status = spi_sync(spi, &message);
1092 if (status == 0)
1093 memcpy(rxbuf, x[1].rx_buf, n_rx);
1094
1095 if (x[0].tx_buf == buf)
1096 mutex_unlock(&lock);
1097 else
1098 kfree(local_buf);
1099
1100 return status;
1101}
1102EXPORT_SYMBOL_GPL(spi_write_then_read);
1103
1104/*-------------------------------------------------------------------------*/
1105
1106static int __init spi_init(void)
1107{
1108 int status;
1109
1110 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
1111 if (!buf) {
1112 status = -ENOMEM;
1113 goto err0;
1114 }
1115
1116 status = bus_register(&spi_bus_type);
1117 if (status < 0)
1118 goto err1;
1119
1120 status = class_register(&spi_master_class);
1121 if (status < 0)
1122 goto err2;
1123 return 0;
1124
1125err2:
1126 bus_unregister(&spi_bus_type);
1127err1:
1128 kfree(buf);
1129 buf = NULL;
1130err0:
1131 return status;
1132}
1133
1134/* board_info is normally registered in arch_initcall(),
1135 * but even essential drivers wait till later
1136 *
1137 * REVISIT only boardinfo really needs static linking. the rest (device and
1138 * driver registration) _could_ be dynamically linked (modular) ... costs
1139 * include needing to have boardinfo data structures be much more public.
1140 */
1141postcore_initcall(spi_init);
1142
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/of_gpio.h>
22#include <linux/gpio/consumer.h>
23#include <linux/pm_runtime.h>
24#include <linux/pm_domain.h>
25#include <linux/property.h>
26#include <linux/export.h>
27#include <linux/sched/rt.h>
28#include <uapi/linux/sched/types.h>
29#include <linux/delay.h>
30#include <linux/kthread.h>
31#include <linux/ioport.h>
32#include <linux/acpi.h>
33#include <linux/highmem.h>
34#include <linux/idr.h>
35#include <linux/platform_data/x86/apple.h>
36
37#define CREATE_TRACE_POINTS
38#include <trace/events/spi.h>
39EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start);
40EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop);
41
42#include "internals.h"
43
44static DEFINE_IDR(spi_master_idr);
45
46static void spidev_release(struct device *dev)
47{
48 struct spi_device *spi = to_spi_device(dev);
49
50 spi_controller_put(spi->controller);
51 kfree(spi->driver_override);
52 kfree(spi);
53}
54
55static ssize_t
56modalias_show(struct device *dev, struct device_attribute *a, char *buf)
57{
58 const struct spi_device *spi = to_spi_device(dev);
59 int len;
60
61 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
62 if (len != -ENODEV)
63 return len;
64
65 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
66}
67static DEVICE_ATTR_RO(modalias);
68
69static ssize_t driver_override_store(struct device *dev,
70 struct device_attribute *a,
71 const char *buf, size_t count)
72{
73 struct spi_device *spi = to_spi_device(dev);
74 const char *end = memchr(buf, '\n', count);
75 const size_t len = end ? end - buf : count;
76 const char *driver_override, *old;
77
78 /* We need to keep extra room for a newline when displaying value */
79 if (len >= (PAGE_SIZE - 1))
80 return -EINVAL;
81
82 driver_override = kstrndup(buf, len, GFP_KERNEL);
83 if (!driver_override)
84 return -ENOMEM;
85
86 device_lock(dev);
87 old = spi->driver_override;
88 if (len) {
89 spi->driver_override = driver_override;
90 } else {
91 /* Empty string, disable driver override */
92 spi->driver_override = NULL;
93 kfree(driver_override);
94 }
95 device_unlock(dev);
96 kfree(old);
97
98 return count;
99}
100
101static ssize_t driver_override_show(struct device *dev,
102 struct device_attribute *a, char *buf)
103{
104 const struct spi_device *spi = to_spi_device(dev);
105 ssize_t len;
106
107 device_lock(dev);
108 len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
109 device_unlock(dev);
110 return len;
111}
112static DEVICE_ATTR_RW(driver_override);
113
114#define SPI_STATISTICS_ATTRS(field, file) \
115static ssize_t spi_controller_##field##_show(struct device *dev, \
116 struct device_attribute *attr, \
117 char *buf) \
118{ \
119 struct spi_controller *ctlr = container_of(dev, \
120 struct spi_controller, dev); \
121 return spi_statistics_##field##_show(&ctlr->statistics, buf); \
122} \
123static struct device_attribute dev_attr_spi_controller_##field = { \
124 .attr = { .name = file, .mode = 0444 }, \
125 .show = spi_controller_##field##_show, \
126}; \
127static ssize_t spi_device_##field##_show(struct device *dev, \
128 struct device_attribute *attr, \
129 char *buf) \
130{ \
131 struct spi_device *spi = to_spi_device(dev); \
132 return spi_statistics_##field##_show(&spi->statistics, buf); \
133} \
134static struct device_attribute dev_attr_spi_device_##field = { \
135 .attr = { .name = file, .mode = 0444 }, \
136 .show = spi_device_##field##_show, \
137}
138
139#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
140static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
141 char *buf) \
142{ \
143 unsigned long flags; \
144 ssize_t len; \
145 spin_lock_irqsave(&stat->lock, flags); \
146 len = sprintf(buf, format_string, stat->field); \
147 spin_unlock_irqrestore(&stat->lock, flags); \
148 return len; \
149} \
150SPI_STATISTICS_ATTRS(name, file)
151
152#define SPI_STATISTICS_SHOW(field, format_string) \
153 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
154 field, format_string)
155
156SPI_STATISTICS_SHOW(messages, "%lu");
157SPI_STATISTICS_SHOW(transfers, "%lu");
158SPI_STATISTICS_SHOW(errors, "%lu");
159SPI_STATISTICS_SHOW(timedout, "%lu");
160
161SPI_STATISTICS_SHOW(spi_sync, "%lu");
162SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
163SPI_STATISTICS_SHOW(spi_async, "%lu");
164
165SPI_STATISTICS_SHOW(bytes, "%llu");
166SPI_STATISTICS_SHOW(bytes_rx, "%llu");
167SPI_STATISTICS_SHOW(bytes_tx, "%llu");
168
169#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
170 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
171 "transfer_bytes_histo_" number, \
172 transfer_bytes_histo[index], "%lu")
173SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
174SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
175SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
176SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
177SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
178SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
179SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
180SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
181SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
182SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
183SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
184SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
185SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
186SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
187SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
188SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
189SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
190
191SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
192
193static struct attribute *spi_dev_attrs[] = {
194 &dev_attr_modalias.attr,
195 &dev_attr_driver_override.attr,
196 NULL,
197};
198
199static const struct attribute_group spi_dev_group = {
200 .attrs = spi_dev_attrs,
201};
202
203static struct attribute *spi_device_statistics_attrs[] = {
204 &dev_attr_spi_device_messages.attr,
205 &dev_attr_spi_device_transfers.attr,
206 &dev_attr_spi_device_errors.attr,
207 &dev_attr_spi_device_timedout.attr,
208 &dev_attr_spi_device_spi_sync.attr,
209 &dev_attr_spi_device_spi_sync_immediate.attr,
210 &dev_attr_spi_device_spi_async.attr,
211 &dev_attr_spi_device_bytes.attr,
212 &dev_attr_spi_device_bytes_rx.attr,
213 &dev_attr_spi_device_bytes_tx.attr,
214 &dev_attr_spi_device_transfer_bytes_histo0.attr,
215 &dev_attr_spi_device_transfer_bytes_histo1.attr,
216 &dev_attr_spi_device_transfer_bytes_histo2.attr,
217 &dev_attr_spi_device_transfer_bytes_histo3.attr,
218 &dev_attr_spi_device_transfer_bytes_histo4.attr,
219 &dev_attr_spi_device_transfer_bytes_histo5.attr,
220 &dev_attr_spi_device_transfer_bytes_histo6.attr,
221 &dev_attr_spi_device_transfer_bytes_histo7.attr,
222 &dev_attr_spi_device_transfer_bytes_histo8.attr,
223 &dev_attr_spi_device_transfer_bytes_histo9.attr,
224 &dev_attr_spi_device_transfer_bytes_histo10.attr,
225 &dev_attr_spi_device_transfer_bytes_histo11.attr,
226 &dev_attr_spi_device_transfer_bytes_histo12.attr,
227 &dev_attr_spi_device_transfer_bytes_histo13.attr,
228 &dev_attr_spi_device_transfer_bytes_histo14.attr,
229 &dev_attr_spi_device_transfer_bytes_histo15.attr,
230 &dev_attr_spi_device_transfer_bytes_histo16.attr,
231 &dev_attr_spi_device_transfers_split_maxsize.attr,
232 NULL,
233};
234
235static const struct attribute_group spi_device_statistics_group = {
236 .name = "statistics",
237 .attrs = spi_device_statistics_attrs,
238};
239
240static const struct attribute_group *spi_dev_groups[] = {
241 &spi_dev_group,
242 &spi_device_statistics_group,
243 NULL,
244};
245
246static struct attribute *spi_controller_statistics_attrs[] = {
247 &dev_attr_spi_controller_messages.attr,
248 &dev_attr_spi_controller_transfers.attr,
249 &dev_attr_spi_controller_errors.attr,
250 &dev_attr_spi_controller_timedout.attr,
251 &dev_attr_spi_controller_spi_sync.attr,
252 &dev_attr_spi_controller_spi_sync_immediate.attr,
253 &dev_attr_spi_controller_spi_async.attr,
254 &dev_attr_spi_controller_bytes.attr,
255 &dev_attr_spi_controller_bytes_rx.attr,
256 &dev_attr_spi_controller_bytes_tx.attr,
257 &dev_attr_spi_controller_transfer_bytes_histo0.attr,
258 &dev_attr_spi_controller_transfer_bytes_histo1.attr,
259 &dev_attr_spi_controller_transfer_bytes_histo2.attr,
260 &dev_attr_spi_controller_transfer_bytes_histo3.attr,
261 &dev_attr_spi_controller_transfer_bytes_histo4.attr,
262 &dev_attr_spi_controller_transfer_bytes_histo5.attr,
263 &dev_attr_spi_controller_transfer_bytes_histo6.attr,
264 &dev_attr_spi_controller_transfer_bytes_histo7.attr,
265 &dev_attr_spi_controller_transfer_bytes_histo8.attr,
266 &dev_attr_spi_controller_transfer_bytes_histo9.attr,
267 &dev_attr_spi_controller_transfer_bytes_histo10.attr,
268 &dev_attr_spi_controller_transfer_bytes_histo11.attr,
269 &dev_attr_spi_controller_transfer_bytes_histo12.attr,
270 &dev_attr_spi_controller_transfer_bytes_histo13.attr,
271 &dev_attr_spi_controller_transfer_bytes_histo14.attr,
272 &dev_attr_spi_controller_transfer_bytes_histo15.attr,
273 &dev_attr_spi_controller_transfer_bytes_histo16.attr,
274 &dev_attr_spi_controller_transfers_split_maxsize.attr,
275 NULL,
276};
277
278static const struct attribute_group spi_controller_statistics_group = {
279 .name = "statistics",
280 .attrs = spi_controller_statistics_attrs,
281};
282
283static const struct attribute_group *spi_master_groups[] = {
284 &spi_controller_statistics_group,
285 NULL,
286};
287
288void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
289 struct spi_transfer *xfer,
290 struct spi_controller *ctlr)
291{
292 unsigned long flags;
293 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
294
295 if (l2len < 0)
296 l2len = 0;
297
298 spin_lock_irqsave(&stats->lock, flags);
299
300 stats->transfers++;
301 stats->transfer_bytes_histo[l2len]++;
302
303 stats->bytes += xfer->len;
304 if ((xfer->tx_buf) &&
305 (xfer->tx_buf != ctlr->dummy_tx))
306 stats->bytes_tx += xfer->len;
307 if ((xfer->rx_buf) &&
308 (xfer->rx_buf != ctlr->dummy_rx))
309 stats->bytes_rx += xfer->len;
310
311 spin_unlock_irqrestore(&stats->lock, flags);
312}
313EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
314
315/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
316 * and the sysfs version makes coldplug work too.
317 */
318
319static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
320 const struct spi_device *sdev)
321{
322 while (id->name[0]) {
323 if (!strcmp(sdev->modalias, id->name))
324 return id;
325 id++;
326 }
327 return NULL;
328}
329
330const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
331{
332 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
333
334 return spi_match_id(sdrv->id_table, sdev);
335}
336EXPORT_SYMBOL_GPL(spi_get_device_id);
337
338static int spi_match_device(struct device *dev, struct device_driver *drv)
339{
340 const struct spi_device *spi = to_spi_device(dev);
341 const struct spi_driver *sdrv = to_spi_driver(drv);
342
343 /* Check override first, and if set, only use the named driver */
344 if (spi->driver_override)
345 return strcmp(spi->driver_override, drv->name) == 0;
346
347 /* Attempt an OF style match */
348 if (of_driver_match_device(dev, drv))
349 return 1;
350
351 /* Then try ACPI */
352 if (acpi_driver_match_device(dev, drv))
353 return 1;
354
355 if (sdrv->id_table)
356 return !!spi_match_id(sdrv->id_table, spi);
357
358 return strcmp(spi->modalias, drv->name) == 0;
359}
360
361static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
362{
363 const struct spi_device *spi = to_spi_device(dev);
364 int rc;
365
366 rc = acpi_device_uevent_modalias(dev, env);
367 if (rc != -ENODEV)
368 return rc;
369
370 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
371}
372
373static int spi_probe(struct device *dev)
374{
375 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
376 struct spi_device *spi = to_spi_device(dev);
377 int ret;
378
379 ret = of_clk_set_defaults(dev->of_node, false);
380 if (ret)
381 return ret;
382
383 if (dev->of_node) {
384 spi->irq = of_irq_get(dev->of_node, 0);
385 if (spi->irq == -EPROBE_DEFER)
386 return -EPROBE_DEFER;
387 if (spi->irq < 0)
388 spi->irq = 0;
389 }
390
391 ret = dev_pm_domain_attach(dev, true);
392 if (ret)
393 return ret;
394
395 if (sdrv->probe) {
396 ret = sdrv->probe(spi);
397 if (ret)
398 dev_pm_domain_detach(dev, true);
399 }
400
401 return ret;
402}
403
404static int spi_remove(struct device *dev)
405{
406 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
407
408 if (sdrv->remove) {
409 int ret;
410
411 ret = sdrv->remove(to_spi_device(dev));
412 if (ret)
413 dev_warn(dev,
414 "Failed to unbind driver (%pe), ignoring\n",
415 ERR_PTR(ret));
416 }
417
418 dev_pm_domain_detach(dev, true);
419
420 return 0;
421}
422
423static void spi_shutdown(struct device *dev)
424{
425 if (dev->driver) {
426 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
427
428 if (sdrv->shutdown)
429 sdrv->shutdown(to_spi_device(dev));
430 }
431}
432
433struct bus_type spi_bus_type = {
434 .name = "spi",
435 .dev_groups = spi_dev_groups,
436 .match = spi_match_device,
437 .uevent = spi_uevent,
438 .probe = spi_probe,
439 .remove = spi_remove,
440 .shutdown = spi_shutdown,
441};
442EXPORT_SYMBOL_GPL(spi_bus_type);
443
444/**
445 * __spi_register_driver - register a SPI driver
446 * @owner: owner module of the driver to register
447 * @sdrv: the driver to register
448 * Context: can sleep
449 *
450 * Return: zero on success, else a negative error code.
451 */
452int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
453{
454 sdrv->driver.owner = owner;
455 sdrv->driver.bus = &spi_bus_type;
456 return driver_register(&sdrv->driver);
457}
458EXPORT_SYMBOL_GPL(__spi_register_driver);
459
460/*-------------------------------------------------------------------------*/
461
462/* SPI devices should normally not be created by SPI device drivers; that
463 * would make them board-specific. Similarly with SPI controller drivers.
464 * Device registration normally goes into like arch/.../mach.../board-YYY.c
465 * with other readonly (flashable) information about mainboard devices.
466 */
467
468struct boardinfo {
469 struct list_head list;
470 struct spi_board_info board_info;
471};
472
473static LIST_HEAD(board_list);
474static LIST_HEAD(spi_controller_list);
475
476/*
477 * Used to protect add/del operation for board_info list and
478 * spi_controller list, and their matching process
479 * also used to protect object of type struct idr
480 */
481static DEFINE_MUTEX(board_lock);
482
483/**
484 * spi_alloc_device - Allocate a new SPI device
485 * @ctlr: Controller to which device is connected
486 * Context: can sleep
487 *
488 * Allows a driver to allocate and initialize a spi_device without
489 * registering it immediately. This allows a driver to directly
490 * fill the spi_device with device parameters before calling
491 * spi_add_device() on it.
492 *
493 * Caller is responsible to call spi_add_device() on the returned
494 * spi_device structure to add it to the SPI controller. If the caller
495 * needs to discard the spi_device without adding it, then it should
496 * call spi_dev_put() on it.
497 *
498 * Return: a pointer to the new device, or NULL.
499 */
500struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
501{
502 struct spi_device *spi;
503
504 if (!spi_controller_get(ctlr))
505 return NULL;
506
507 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
508 if (!spi) {
509 spi_controller_put(ctlr);
510 return NULL;
511 }
512
513 spi->master = spi->controller = ctlr;
514 spi->dev.parent = &ctlr->dev;
515 spi->dev.bus = &spi_bus_type;
516 spi->dev.release = spidev_release;
517 spi->cs_gpio = -ENOENT;
518 spi->mode = ctlr->buswidth_override_bits;
519
520 spin_lock_init(&spi->statistics.lock);
521
522 device_initialize(&spi->dev);
523 return spi;
524}
525EXPORT_SYMBOL_GPL(spi_alloc_device);
526
527static void spi_dev_set_name(struct spi_device *spi)
528{
529 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
530
531 if (adev) {
532 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
533 return;
534 }
535
536 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
537 spi->chip_select);
538}
539
540static int spi_dev_check(struct device *dev, void *data)
541{
542 struct spi_device *spi = to_spi_device(dev);
543 struct spi_device *new_spi = data;
544
545 if (spi->controller == new_spi->controller &&
546 spi->chip_select == new_spi->chip_select)
547 return -EBUSY;
548 return 0;
549}
550
551static void spi_cleanup(struct spi_device *spi)
552{
553 if (spi->controller->cleanup)
554 spi->controller->cleanup(spi);
555}
556
557static int __spi_add_device(struct spi_device *spi)
558{
559 struct spi_controller *ctlr = spi->controller;
560 struct device *dev = ctlr->dev.parent;
561 int status;
562
563 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
564 if (status) {
565 dev_err(dev, "chipselect %d already in use\n",
566 spi->chip_select);
567 return status;
568 }
569
570 /* Controller may unregister concurrently */
571 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
572 !device_is_registered(&ctlr->dev)) {
573 return -ENODEV;
574 }
575
576 /* Descriptors take precedence */
577 if (ctlr->cs_gpiods)
578 spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
579 else if (ctlr->cs_gpios)
580 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
581
582 /* Drivers may modify this initial i/o setup, but will
583 * normally rely on the device being setup. Devices
584 * using SPI_CS_HIGH can't coexist well otherwise...
585 */
586 status = spi_setup(spi);
587 if (status < 0) {
588 dev_err(dev, "can't setup %s, status %d\n",
589 dev_name(&spi->dev), status);
590 return status;
591 }
592
593 /* Device may be bound to an active driver when this returns */
594 status = device_add(&spi->dev);
595 if (status < 0) {
596 dev_err(dev, "can't add %s, status %d\n",
597 dev_name(&spi->dev), status);
598 spi_cleanup(spi);
599 } else {
600 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
601 }
602
603 return status;
604}
605
606/**
607 * spi_add_device - Add spi_device allocated with spi_alloc_device
608 * @spi: spi_device to register
609 *
610 * Companion function to spi_alloc_device. Devices allocated with
611 * spi_alloc_device can be added onto the spi bus with this function.
612 *
613 * Return: 0 on success; negative errno on failure
614 */
615int spi_add_device(struct spi_device *spi)
616{
617 struct spi_controller *ctlr = spi->controller;
618 struct device *dev = ctlr->dev.parent;
619 int status;
620
621 /* Chipselects are numbered 0..max; validate. */
622 if (spi->chip_select >= ctlr->num_chipselect) {
623 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
624 ctlr->num_chipselect);
625 return -EINVAL;
626 }
627
628 /* Set the bus ID string */
629 spi_dev_set_name(spi);
630
631 /* We need to make sure there's no other device with this
632 * chipselect **BEFORE** we call setup(), else we'll trash
633 * its configuration. Lock against concurrent add() calls.
634 */
635 mutex_lock(&ctlr->add_lock);
636 status = __spi_add_device(spi);
637 mutex_unlock(&ctlr->add_lock);
638 return status;
639}
640EXPORT_SYMBOL_GPL(spi_add_device);
641
642static int spi_add_device_locked(struct spi_device *spi)
643{
644 struct spi_controller *ctlr = spi->controller;
645 struct device *dev = ctlr->dev.parent;
646
647 /* Chipselects are numbered 0..max; validate. */
648 if (spi->chip_select >= ctlr->num_chipselect) {
649 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
650 ctlr->num_chipselect);
651 return -EINVAL;
652 }
653
654 /* Set the bus ID string */
655 spi_dev_set_name(spi);
656
657 WARN_ON(!mutex_is_locked(&ctlr->add_lock));
658 return __spi_add_device(spi);
659}
660
661/**
662 * spi_new_device - instantiate one new SPI device
663 * @ctlr: Controller to which device is connected
664 * @chip: Describes the SPI device
665 * Context: can sleep
666 *
667 * On typical mainboards, this is purely internal; and it's not needed
668 * after board init creates the hard-wired devices. Some development
669 * platforms may not be able to use spi_register_board_info though, and
670 * this is exported so that for example a USB or parport based adapter
671 * driver could add devices (which it would learn about out-of-band).
672 *
673 * Return: the new device, or NULL.
674 */
675struct spi_device *spi_new_device(struct spi_controller *ctlr,
676 struct spi_board_info *chip)
677{
678 struct spi_device *proxy;
679 int status;
680
681 /* NOTE: caller did any chip->bus_num checks necessary.
682 *
683 * Also, unless we change the return value convention to use
684 * error-or-pointer (not NULL-or-pointer), troubleshootability
685 * suggests syslogged diagnostics are best here (ugh).
686 */
687
688 proxy = spi_alloc_device(ctlr);
689 if (!proxy)
690 return NULL;
691
692 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
693
694 proxy->chip_select = chip->chip_select;
695 proxy->max_speed_hz = chip->max_speed_hz;
696 proxy->mode = chip->mode;
697 proxy->irq = chip->irq;
698 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
699 proxy->dev.platform_data = (void *) chip->platform_data;
700 proxy->controller_data = chip->controller_data;
701 proxy->controller_state = NULL;
702
703 if (chip->swnode) {
704 status = device_add_software_node(&proxy->dev, chip->swnode);
705 if (status) {
706 dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n",
707 chip->modalias, status);
708 goto err_dev_put;
709 }
710 }
711
712 status = spi_add_device(proxy);
713 if (status < 0)
714 goto err_dev_put;
715
716 return proxy;
717
718err_dev_put:
719 device_remove_software_node(&proxy->dev);
720 spi_dev_put(proxy);
721 return NULL;
722}
723EXPORT_SYMBOL_GPL(spi_new_device);
724
725/**
726 * spi_unregister_device - unregister a single SPI device
727 * @spi: spi_device to unregister
728 *
729 * Start making the passed SPI device vanish. Normally this would be handled
730 * by spi_unregister_controller().
731 */
732void spi_unregister_device(struct spi_device *spi)
733{
734 if (!spi)
735 return;
736
737 if (spi->dev.of_node) {
738 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
739 of_node_put(spi->dev.of_node);
740 }
741 if (ACPI_COMPANION(&spi->dev))
742 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
743 device_remove_software_node(&spi->dev);
744 device_del(&spi->dev);
745 spi_cleanup(spi);
746 put_device(&spi->dev);
747}
748EXPORT_SYMBOL_GPL(spi_unregister_device);
749
750static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
751 struct spi_board_info *bi)
752{
753 struct spi_device *dev;
754
755 if (ctlr->bus_num != bi->bus_num)
756 return;
757
758 dev = spi_new_device(ctlr, bi);
759 if (!dev)
760 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
761 bi->modalias);
762}
763
764/**
765 * spi_register_board_info - register SPI devices for a given board
766 * @info: array of chip descriptors
767 * @n: how many descriptors are provided
768 * Context: can sleep
769 *
770 * Board-specific early init code calls this (probably during arch_initcall)
771 * with segments of the SPI device table. Any device nodes are created later,
772 * after the relevant parent SPI controller (bus_num) is defined. We keep
773 * this table of devices forever, so that reloading a controller driver will
774 * not make Linux forget about these hard-wired devices.
775 *
776 * Other code can also call this, e.g. a particular add-on board might provide
777 * SPI devices through its expansion connector, so code initializing that board
778 * would naturally declare its SPI devices.
779 *
780 * The board info passed can safely be __initdata ... but be careful of
781 * any embedded pointers (platform_data, etc), they're copied as-is.
782 *
783 * Return: zero on success, else a negative error code.
784 */
785int spi_register_board_info(struct spi_board_info const *info, unsigned n)
786{
787 struct boardinfo *bi;
788 int i;
789
790 if (!n)
791 return 0;
792
793 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
794 if (!bi)
795 return -ENOMEM;
796
797 for (i = 0; i < n; i++, bi++, info++) {
798 struct spi_controller *ctlr;
799
800 memcpy(&bi->board_info, info, sizeof(*info));
801
802 mutex_lock(&board_lock);
803 list_add_tail(&bi->list, &board_list);
804 list_for_each_entry(ctlr, &spi_controller_list, list)
805 spi_match_controller_to_boardinfo(ctlr,
806 &bi->board_info);
807 mutex_unlock(&board_lock);
808 }
809
810 return 0;
811}
812
813/*-------------------------------------------------------------------------*/
814
815static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
816{
817 bool activate = enable;
818
819 /*
820 * Avoid calling into the driver (or doing delays) if the chip select
821 * isn't actually changing from the last time this was called.
822 */
823 if (!force && (spi->controller->last_cs_enable == enable) &&
824 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
825 return;
826
827 trace_spi_set_cs(spi, activate);
828
829 spi->controller->last_cs_enable = enable;
830 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
831
832 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
833 !spi->controller->set_cs_timing) {
834 if (activate)
835 spi_delay_exec(&spi->controller->cs_setup, NULL);
836 else
837 spi_delay_exec(&spi->controller->cs_hold, NULL);
838 }
839
840 if (spi->mode & SPI_CS_HIGH)
841 enable = !enable;
842
843 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
844 if (!(spi->mode & SPI_NO_CS)) {
845 if (spi->cs_gpiod) {
846 /*
847 * Historically ACPI has no means of the GPIO polarity and
848 * thus the SPISerialBus() resource defines it on the per-chip
849 * basis. In order to avoid a chain of negations, the GPIO
850 * polarity is considered being Active High. Even for the cases
851 * when _DSD() is involved (in the updated versions of ACPI)
852 * the GPIO CS polarity must be defined Active High to avoid
853 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
854 * into account.
855 */
856 if (has_acpi_companion(&spi->dev))
857 gpiod_set_value_cansleep(spi->cs_gpiod, !enable);
858 else
859 /* Polarity handled by GPIO library */
860 gpiod_set_value_cansleep(spi->cs_gpiod, activate);
861 } else {
862 /*
863 * invert the enable line, as active low is
864 * default for SPI.
865 */
866 gpio_set_value_cansleep(spi->cs_gpio, !enable);
867 }
868 }
869 /* Some SPI masters need both GPIO CS & slave_select */
870 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
871 spi->controller->set_cs)
872 spi->controller->set_cs(spi, !enable);
873 } else if (spi->controller->set_cs) {
874 spi->controller->set_cs(spi, !enable);
875 }
876
877 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
878 !spi->controller->set_cs_timing) {
879 if (!activate)
880 spi_delay_exec(&spi->controller->cs_inactive, NULL);
881 }
882}
883
884#ifdef CONFIG_HAS_DMA
885int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
886 struct sg_table *sgt, void *buf, size_t len,
887 enum dma_data_direction dir)
888{
889 const bool vmalloced_buf = is_vmalloc_addr(buf);
890 unsigned int max_seg_size = dma_get_max_seg_size(dev);
891#ifdef CONFIG_HIGHMEM
892 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
893 (unsigned long)buf < (PKMAP_BASE +
894 (LAST_PKMAP * PAGE_SIZE)));
895#else
896 const bool kmap_buf = false;
897#endif
898 int desc_len;
899 int sgs;
900 struct page *vm_page;
901 struct scatterlist *sg;
902 void *sg_buf;
903 size_t min;
904 int i, ret;
905
906 if (vmalloced_buf || kmap_buf) {
907 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
908 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
909 } else if (virt_addr_valid(buf)) {
910 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
911 sgs = DIV_ROUND_UP(len, desc_len);
912 } else {
913 return -EINVAL;
914 }
915
916 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
917 if (ret != 0)
918 return ret;
919
920 sg = &sgt->sgl[0];
921 for (i = 0; i < sgs; i++) {
922
923 if (vmalloced_buf || kmap_buf) {
924 /*
925 * Next scatterlist entry size is the minimum between
926 * the desc_len and the remaining buffer length that
927 * fits in a page.
928 */
929 min = min_t(size_t, desc_len,
930 min_t(size_t, len,
931 PAGE_SIZE - offset_in_page(buf)));
932 if (vmalloced_buf)
933 vm_page = vmalloc_to_page(buf);
934 else
935 vm_page = kmap_to_page(buf);
936 if (!vm_page) {
937 sg_free_table(sgt);
938 return -ENOMEM;
939 }
940 sg_set_page(sg, vm_page,
941 min, offset_in_page(buf));
942 } else {
943 min = min_t(size_t, len, desc_len);
944 sg_buf = buf;
945 sg_set_buf(sg, sg_buf, min);
946 }
947
948 buf += min;
949 len -= min;
950 sg = sg_next(sg);
951 }
952
953 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
954 if (!ret)
955 ret = -ENOMEM;
956 if (ret < 0) {
957 sg_free_table(sgt);
958 return ret;
959 }
960
961 sgt->nents = ret;
962
963 return 0;
964}
965
966void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
967 struct sg_table *sgt, enum dma_data_direction dir)
968{
969 if (sgt->orig_nents) {
970 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
971 sg_free_table(sgt);
972 }
973}
974
975static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
976{
977 struct device *tx_dev, *rx_dev;
978 struct spi_transfer *xfer;
979 int ret;
980
981 if (!ctlr->can_dma)
982 return 0;
983
984 if (ctlr->dma_tx)
985 tx_dev = ctlr->dma_tx->device->dev;
986 else if (ctlr->dma_map_dev)
987 tx_dev = ctlr->dma_map_dev;
988 else
989 tx_dev = ctlr->dev.parent;
990
991 if (ctlr->dma_rx)
992 rx_dev = ctlr->dma_rx->device->dev;
993 else if (ctlr->dma_map_dev)
994 rx_dev = ctlr->dma_map_dev;
995 else
996 rx_dev = ctlr->dev.parent;
997
998 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
999 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1000 continue;
1001
1002 if (xfer->tx_buf != NULL) {
1003 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
1004 (void *)xfer->tx_buf, xfer->len,
1005 DMA_TO_DEVICE);
1006 if (ret != 0)
1007 return ret;
1008 }
1009
1010 if (xfer->rx_buf != NULL) {
1011 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
1012 xfer->rx_buf, xfer->len,
1013 DMA_FROM_DEVICE);
1014 if (ret != 0) {
1015 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
1016 DMA_TO_DEVICE);
1017 return ret;
1018 }
1019 }
1020 }
1021
1022 ctlr->cur_msg_mapped = true;
1023
1024 return 0;
1025}
1026
1027static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
1028{
1029 struct spi_transfer *xfer;
1030 struct device *tx_dev, *rx_dev;
1031
1032 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
1033 return 0;
1034
1035 if (ctlr->dma_tx)
1036 tx_dev = ctlr->dma_tx->device->dev;
1037 else
1038 tx_dev = ctlr->dev.parent;
1039
1040 if (ctlr->dma_rx)
1041 rx_dev = ctlr->dma_rx->device->dev;
1042 else
1043 rx_dev = ctlr->dev.parent;
1044
1045 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1046 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1047 continue;
1048
1049 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1050 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1051 }
1052
1053 ctlr->cur_msg_mapped = false;
1054
1055 return 0;
1056}
1057#else /* !CONFIG_HAS_DMA */
1058static inline int __spi_map_msg(struct spi_controller *ctlr,
1059 struct spi_message *msg)
1060{
1061 return 0;
1062}
1063
1064static inline int __spi_unmap_msg(struct spi_controller *ctlr,
1065 struct spi_message *msg)
1066{
1067 return 0;
1068}
1069#endif /* !CONFIG_HAS_DMA */
1070
1071static inline int spi_unmap_msg(struct spi_controller *ctlr,
1072 struct spi_message *msg)
1073{
1074 struct spi_transfer *xfer;
1075
1076 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1077 /*
1078 * Restore the original value of tx_buf or rx_buf if they are
1079 * NULL.
1080 */
1081 if (xfer->tx_buf == ctlr->dummy_tx)
1082 xfer->tx_buf = NULL;
1083 if (xfer->rx_buf == ctlr->dummy_rx)
1084 xfer->rx_buf = NULL;
1085 }
1086
1087 return __spi_unmap_msg(ctlr, msg);
1088}
1089
1090static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1091{
1092 struct spi_transfer *xfer;
1093 void *tmp;
1094 unsigned int max_tx, max_rx;
1095
1096 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1097 && !(msg->spi->mode & SPI_3WIRE)) {
1098 max_tx = 0;
1099 max_rx = 0;
1100
1101 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1102 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1103 !xfer->tx_buf)
1104 max_tx = max(xfer->len, max_tx);
1105 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1106 !xfer->rx_buf)
1107 max_rx = max(xfer->len, max_rx);
1108 }
1109
1110 if (max_tx) {
1111 tmp = krealloc(ctlr->dummy_tx, max_tx,
1112 GFP_KERNEL | GFP_DMA);
1113 if (!tmp)
1114 return -ENOMEM;
1115 ctlr->dummy_tx = tmp;
1116 memset(tmp, 0, max_tx);
1117 }
1118
1119 if (max_rx) {
1120 tmp = krealloc(ctlr->dummy_rx, max_rx,
1121 GFP_KERNEL | GFP_DMA);
1122 if (!tmp)
1123 return -ENOMEM;
1124 ctlr->dummy_rx = tmp;
1125 }
1126
1127 if (max_tx || max_rx) {
1128 list_for_each_entry(xfer, &msg->transfers,
1129 transfer_list) {
1130 if (!xfer->len)
1131 continue;
1132 if (!xfer->tx_buf)
1133 xfer->tx_buf = ctlr->dummy_tx;
1134 if (!xfer->rx_buf)
1135 xfer->rx_buf = ctlr->dummy_rx;
1136 }
1137 }
1138 }
1139
1140 return __spi_map_msg(ctlr, msg);
1141}
1142
1143static int spi_transfer_wait(struct spi_controller *ctlr,
1144 struct spi_message *msg,
1145 struct spi_transfer *xfer)
1146{
1147 struct spi_statistics *statm = &ctlr->statistics;
1148 struct spi_statistics *stats = &msg->spi->statistics;
1149 u32 speed_hz = xfer->speed_hz;
1150 unsigned long long ms;
1151
1152 if (spi_controller_is_slave(ctlr)) {
1153 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1154 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1155 return -EINTR;
1156 }
1157 } else {
1158 if (!speed_hz)
1159 speed_hz = 100000;
1160
1161 /*
1162 * For each byte we wait for 8 cycles of the SPI clock.
1163 * Since speed is defined in Hz and we want milliseconds,
1164 * use respective multiplier, but before the division,
1165 * otherwise we may get 0 for short transfers.
1166 */
1167 ms = 8LL * MSEC_PER_SEC * xfer->len;
1168 do_div(ms, speed_hz);
1169
1170 /*
1171 * Increase it twice and add 200 ms tolerance, use
1172 * predefined maximum in case of overflow.
1173 */
1174 ms += ms + 200;
1175 if (ms > UINT_MAX)
1176 ms = UINT_MAX;
1177
1178 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1179 msecs_to_jiffies(ms));
1180
1181 if (ms == 0) {
1182 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1183 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1184 dev_err(&msg->spi->dev,
1185 "SPI transfer timed out\n");
1186 return -ETIMEDOUT;
1187 }
1188 }
1189
1190 return 0;
1191}
1192
1193static void _spi_transfer_delay_ns(u32 ns)
1194{
1195 if (!ns)
1196 return;
1197 if (ns <= NSEC_PER_USEC) {
1198 ndelay(ns);
1199 } else {
1200 u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC);
1201
1202 if (us <= 10)
1203 udelay(us);
1204 else
1205 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1206 }
1207}
1208
1209int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1210{
1211 u32 delay = _delay->value;
1212 u32 unit = _delay->unit;
1213 u32 hz;
1214
1215 if (!delay)
1216 return 0;
1217
1218 switch (unit) {
1219 case SPI_DELAY_UNIT_USECS:
1220 delay *= NSEC_PER_USEC;
1221 break;
1222 case SPI_DELAY_UNIT_NSECS:
1223 /* Nothing to do here */
1224 break;
1225 case SPI_DELAY_UNIT_SCK:
1226 /* clock cycles need to be obtained from spi_transfer */
1227 if (!xfer)
1228 return -EINVAL;
1229 /*
1230 * If there is unknown effective speed, approximate it
1231 * by underestimating with half of the requested hz.
1232 */
1233 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1234 if (!hz)
1235 return -EINVAL;
1236
1237 /* Convert delay to nanoseconds */
1238 delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz);
1239 break;
1240 default:
1241 return -EINVAL;
1242 }
1243
1244 return delay;
1245}
1246EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1247
1248int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1249{
1250 int delay;
1251
1252 might_sleep();
1253
1254 if (!_delay)
1255 return -EINVAL;
1256
1257 delay = spi_delay_to_ns(_delay, xfer);
1258 if (delay < 0)
1259 return delay;
1260
1261 _spi_transfer_delay_ns(delay);
1262
1263 return 0;
1264}
1265EXPORT_SYMBOL_GPL(spi_delay_exec);
1266
1267static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1268 struct spi_transfer *xfer)
1269{
1270 u32 default_delay_ns = 10 * NSEC_PER_USEC;
1271 u32 delay = xfer->cs_change_delay.value;
1272 u32 unit = xfer->cs_change_delay.unit;
1273 int ret;
1274
1275 /* return early on "fast" mode - for everything but USECS */
1276 if (!delay) {
1277 if (unit == SPI_DELAY_UNIT_USECS)
1278 _spi_transfer_delay_ns(default_delay_ns);
1279 return;
1280 }
1281
1282 ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1283 if (ret) {
1284 dev_err_once(&msg->spi->dev,
1285 "Use of unsupported delay unit %i, using default of %luus\n",
1286 unit, default_delay_ns / NSEC_PER_USEC);
1287 _spi_transfer_delay_ns(default_delay_ns);
1288 }
1289}
1290
1291/*
1292 * spi_transfer_one_message - Default implementation of transfer_one_message()
1293 *
1294 * This is a standard implementation of transfer_one_message() for
1295 * drivers which implement a transfer_one() operation. It provides
1296 * standard handling of delays and chip select management.
1297 */
1298static int spi_transfer_one_message(struct spi_controller *ctlr,
1299 struct spi_message *msg)
1300{
1301 struct spi_transfer *xfer;
1302 bool keep_cs = false;
1303 int ret = 0;
1304 struct spi_statistics *statm = &ctlr->statistics;
1305 struct spi_statistics *stats = &msg->spi->statistics;
1306
1307 spi_set_cs(msg->spi, true, false);
1308
1309 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1310 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1311
1312 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1313 trace_spi_transfer_start(msg, xfer);
1314
1315 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1316 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1317
1318 if (!ctlr->ptp_sts_supported) {
1319 xfer->ptp_sts_word_pre = 0;
1320 ptp_read_system_prets(xfer->ptp_sts);
1321 }
1322
1323 if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) {
1324 reinit_completion(&ctlr->xfer_completion);
1325
1326fallback_pio:
1327 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1328 if (ret < 0) {
1329 if (ctlr->cur_msg_mapped &&
1330 (xfer->error & SPI_TRANS_FAIL_NO_START)) {
1331 __spi_unmap_msg(ctlr, msg);
1332 ctlr->fallback = true;
1333 xfer->error &= ~SPI_TRANS_FAIL_NO_START;
1334 goto fallback_pio;
1335 }
1336
1337 SPI_STATISTICS_INCREMENT_FIELD(statm,
1338 errors);
1339 SPI_STATISTICS_INCREMENT_FIELD(stats,
1340 errors);
1341 dev_err(&msg->spi->dev,
1342 "SPI transfer failed: %d\n", ret);
1343 goto out;
1344 }
1345
1346 if (ret > 0) {
1347 ret = spi_transfer_wait(ctlr, msg, xfer);
1348 if (ret < 0)
1349 msg->status = ret;
1350 }
1351 } else {
1352 if (xfer->len)
1353 dev_err(&msg->spi->dev,
1354 "Bufferless transfer has length %u\n",
1355 xfer->len);
1356 }
1357
1358 if (!ctlr->ptp_sts_supported) {
1359 ptp_read_system_postts(xfer->ptp_sts);
1360 xfer->ptp_sts_word_post = xfer->len;
1361 }
1362
1363 trace_spi_transfer_stop(msg, xfer);
1364
1365 if (msg->status != -EINPROGRESS)
1366 goto out;
1367
1368 spi_transfer_delay_exec(xfer);
1369
1370 if (xfer->cs_change) {
1371 if (list_is_last(&xfer->transfer_list,
1372 &msg->transfers)) {
1373 keep_cs = true;
1374 } else {
1375 spi_set_cs(msg->spi, false, false);
1376 _spi_transfer_cs_change_delay(msg, xfer);
1377 spi_set_cs(msg->spi, true, false);
1378 }
1379 }
1380
1381 msg->actual_length += xfer->len;
1382 }
1383
1384out:
1385 if (ret != 0 || !keep_cs)
1386 spi_set_cs(msg->spi, false, false);
1387
1388 if (msg->status == -EINPROGRESS)
1389 msg->status = ret;
1390
1391 if (msg->status && ctlr->handle_err)
1392 ctlr->handle_err(ctlr, msg);
1393
1394 spi_finalize_current_message(ctlr);
1395
1396 return ret;
1397}
1398
1399/**
1400 * spi_finalize_current_transfer - report completion of a transfer
1401 * @ctlr: the controller reporting completion
1402 *
1403 * Called by SPI drivers using the core transfer_one_message()
1404 * implementation to notify it that the current interrupt driven
1405 * transfer has finished and the next one may be scheduled.
1406 */
1407void spi_finalize_current_transfer(struct spi_controller *ctlr)
1408{
1409 complete(&ctlr->xfer_completion);
1410}
1411EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1412
1413static void spi_idle_runtime_pm(struct spi_controller *ctlr)
1414{
1415 if (ctlr->auto_runtime_pm) {
1416 pm_runtime_mark_last_busy(ctlr->dev.parent);
1417 pm_runtime_put_autosuspend(ctlr->dev.parent);
1418 }
1419}
1420
1421/**
1422 * __spi_pump_messages - function which processes spi message queue
1423 * @ctlr: controller to process queue for
1424 * @in_kthread: true if we are in the context of the message pump thread
1425 *
1426 * This function checks if there is any spi message in the queue that
1427 * needs processing and if so call out to the driver to initialize hardware
1428 * and transfer each message.
1429 *
1430 * Note that it is called both from the kthread itself and also from
1431 * inside spi_sync(); the queue extraction handling at the top of the
1432 * function should deal with this safely.
1433 */
1434static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1435{
1436 struct spi_transfer *xfer;
1437 struct spi_message *msg;
1438 bool was_busy = false;
1439 unsigned long flags;
1440 int ret;
1441
1442 /* Lock queue */
1443 spin_lock_irqsave(&ctlr->queue_lock, flags);
1444
1445 /* Make sure we are not already running a message */
1446 if (ctlr->cur_msg) {
1447 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1448 return;
1449 }
1450
1451 /* If another context is idling the device then defer */
1452 if (ctlr->idling) {
1453 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1454 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1455 return;
1456 }
1457
1458 /* Check if the queue is idle */
1459 if (list_empty(&ctlr->queue) || !ctlr->running) {
1460 if (!ctlr->busy) {
1461 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1462 return;
1463 }
1464
1465 /* Defer any non-atomic teardown to the thread */
1466 if (!in_kthread) {
1467 if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
1468 !ctlr->unprepare_transfer_hardware) {
1469 spi_idle_runtime_pm(ctlr);
1470 ctlr->busy = false;
1471 trace_spi_controller_idle(ctlr);
1472 } else {
1473 kthread_queue_work(ctlr->kworker,
1474 &ctlr->pump_messages);
1475 }
1476 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1477 return;
1478 }
1479
1480 ctlr->busy = false;
1481 ctlr->idling = true;
1482 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1483
1484 kfree(ctlr->dummy_rx);
1485 ctlr->dummy_rx = NULL;
1486 kfree(ctlr->dummy_tx);
1487 ctlr->dummy_tx = NULL;
1488 if (ctlr->unprepare_transfer_hardware &&
1489 ctlr->unprepare_transfer_hardware(ctlr))
1490 dev_err(&ctlr->dev,
1491 "failed to unprepare transfer hardware\n");
1492 spi_idle_runtime_pm(ctlr);
1493 trace_spi_controller_idle(ctlr);
1494
1495 spin_lock_irqsave(&ctlr->queue_lock, flags);
1496 ctlr->idling = false;
1497 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1498 return;
1499 }
1500
1501 /* Extract head of queue */
1502 msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1503 ctlr->cur_msg = msg;
1504
1505 list_del_init(&msg->queue);
1506 if (ctlr->busy)
1507 was_busy = true;
1508 else
1509 ctlr->busy = true;
1510 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1511
1512 mutex_lock(&ctlr->io_mutex);
1513
1514 if (!was_busy && ctlr->auto_runtime_pm) {
1515 ret = pm_runtime_get_sync(ctlr->dev.parent);
1516 if (ret < 0) {
1517 pm_runtime_put_noidle(ctlr->dev.parent);
1518 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1519 ret);
1520 mutex_unlock(&ctlr->io_mutex);
1521 return;
1522 }
1523 }
1524
1525 if (!was_busy)
1526 trace_spi_controller_busy(ctlr);
1527
1528 if (!was_busy && ctlr->prepare_transfer_hardware) {
1529 ret = ctlr->prepare_transfer_hardware(ctlr);
1530 if (ret) {
1531 dev_err(&ctlr->dev,
1532 "failed to prepare transfer hardware: %d\n",
1533 ret);
1534
1535 if (ctlr->auto_runtime_pm)
1536 pm_runtime_put(ctlr->dev.parent);
1537
1538 msg->status = ret;
1539 spi_finalize_current_message(ctlr);
1540
1541 mutex_unlock(&ctlr->io_mutex);
1542 return;
1543 }
1544 }
1545
1546 trace_spi_message_start(msg);
1547
1548 if (ctlr->prepare_message) {
1549 ret = ctlr->prepare_message(ctlr, msg);
1550 if (ret) {
1551 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1552 ret);
1553 msg->status = ret;
1554 spi_finalize_current_message(ctlr);
1555 goto out;
1556 }
1557 ctlr->cur_msg_prepared = true;
1558 }
1559
1560 ret = spi_map_msg(ctlr, msg);
1561 if (ret) {
1562 msg->status = ret;
1563 spi_finalize_current_message(ctlr);
1564 goto out;
1565 }
1566
1567 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1568 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1569 xfer->ptp_sts_word_pre = 0;
1570 ptp_read_system_prets(xfer->ptp_sts);
1571 }
1572 }
1573
1574 ret = ctlr->transfer_one_message(ctlr, msg);
1575 if (ret) {
1576 dev_err(&ctlr->dev,
1577 "failed to transfer one message from queue\n");
1578 goto out;
1579 }
1580
1581out:
1582 mutex_unlock(&ctlr->io_mutex);
1583
1584 /* Prod the scheduler in case transfer_one() was busy waiting */
1585 if (!ret)
1586 cond_resched();
1587}
1588
1589/**
1590 * spi_pump_messages - kthread work function which processes spi message queue
1591 * @work: pointer to kthread work struct contained in the controller struct
1592 */
1593static void spi_pump_messages(struct kthread_work *work)
1594{
1595 struct spi_controller *ctlr =
1596 container_of(work, struct spi_controller, pump_messages);
1597
1598 __spi_pump_messages(ctlr, true);
1599}
1600
1601/**
1602 * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
1603 * TX timestamp for the requested byte from the SPI
1604 * transfer. The frequency with which this function
1605 * must be called (once per word, once for the whole
1606 * transfer, once per batch of words etc) is arbitrary
1607 * as long as the @tx buffer offset is greater than or
1608 * equal to the requested byte at the time of the
1609 * call. The timestamp is only taken once, at the
1610 * first such call. It is assumed that the driver
1611 * advances its @tx buffer pointer monotonically.
1612 * @ctlr: Pointer to the spi_controller structure of the driver
1613 * @xfer: Pointer to the transfer being timestamped
1614 * @progress: How many words (not bytes) have been transferred so far
1615 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1616 * transfer, for less jitter in time measurement. Only compatible
1617 * with PIO drivers. If true, must follow up with
1618 * spi_take_timestamp_post or otherwise system will crash.
1619 * WARNING: for fully predictable results, the CPU frequency must
1620 * also be under control (governor).
1621 */
1622void spi_take_timestamp_pre(struct spi_controller *ctlr,
1623 struct spi_transfer *xfer,
1624 size_t progress, bool irqs_off)
1625{
1626 if (!xfer->ptp_sts)
1627 return;
1628
1629 if (xfer->timestamped)
1630 return;
1631
1632 if (progress > xfer->ptp_sts_word_pre)
1633 return;
1634
1635 /* Capture the resolution of the timestamp */
1636 xfer->ptp_sts_word_pre = progress;
1637
1638 if (irqs_off) {
1639 local_irq_save(ctlr->irq_flags);
1640 preempt_disable();
1641 }
1642
1643 ptp_read_system_prets(xfer->ptp_sts);
1644}
1645EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
1646
1647/**
1648 * spi_take_timestamp_post - helper for drivers to collect the end of the
1649 * TX timestamp for the requested byte from the SPI
1650 * transfer. Can be called with an arbitrary
1651 * frequency: only the first call where @tx exceeds
1652 * or is equal to the requested word will be
1653 * timestamped.
1654 * @ctlr: Pointer to the spi_controller structure of the driver
1655 * @xfer: Pointer to the transfer being timestamped
1656 * @progress: How many words (not bytes) have been transferred so far
1657 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1658 */
1659void spi_take_timestamp_post(struct spi_controller *ctlr,
1660 struct spi_transfer *xfer,
1661 size_t progress, bool irqs_off)
1662{
1663 if (!xfer->ptp_sts)
1664 return;
1665
1666 if (xfer->timestamped)
1667 return;
1668
1669 if (progress < xfer->ptp_sts_word_post)
1670 return;
1671
1672 ptp_read_system_postts(xfer->ptp_sts);
1673
1674 if (irqs_off) {
1675 local_irq_restore(ctlr->irq_flags);
1676 preempt_enable();
1677 }
1678
1679 /* Capture the resolution of the timestamp */
1680 xfer->ptp_sts_word_post = progress;
1681
1682 xfer->timestamped = true;
1683}
1684EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
1685
1686/**
1687 * spi_set_thread_rt - set the controller to pump at realtime priority
1688 * @ctlr: controller to boost priority of
1689 *
1690 * This can be called because the controller requested realtime priority
1691 * (by setting the ->rt value before calling spi_register_controller()) or
1692 * because a device on the bus said that its transfers needed realtime
1693 * priority.
1694 *
1695 * NOTE: at the moment if any device on a bus says it needs realtime then
1696 * the thread will be at realtime priority for all transfers on that
1697 * controller. If this eventually becomes a problem we may see if we can
1698 * find a way to boost the priority only temporarily during relevant
1699 * transfers.
1700 */
1701static void spi_set_thread_rt(struct spi_controller *ctlr)
1702{
1703 dev_info(&ctlr->dev,
1704 "will run message pump with realtime priority\n");
1705 sched_set_fifo(ctlr->kworker->task);
1706}
1707
1708static int spi_init_queue(struct spi_controller *ctlr)
1709{
1710 ctlr->running = false;
1711 ctlr->busy = false;
1712
1713 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
1714 if (IS_ERR(ctlr->kworker)) {
1715 dev_err(&ctlr->dev, "failed to create message pump kworker\n");
1716 return PTR_ERR(ctlr->kworker);
1717 }
1718
1719 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1720
1721 /*
1722 * Controller config will indicate if this controller should run the
1723 * message pump with high (realtime) priority to reduce the transfer
1724 * latency on the bus by minimising the delay between a transfer
1725 * request and the scheduling of the message pump thread. Without this
1726 * setting the message pump thread will remain at default priority.
1727 */
1728 if (ctlr->rt)
1729 spi_set_thread_rt(ctlr);
1730
1731 return 0;
1732}
1733
1734/**
1735 * spi_get_next_queued_message() - called by driver to check for queued
1736 * messages
1737 * @ctlr: the controller to check for queued messages
1738 *
1739 * If there are more messages in the queue, the next message is returned from
1740 * this call.
1741 *
1742 * Return: the next message in the queue, else NULL if the queue is empty.
1743 */
1744struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1745{
1746 struct spi_message *next;
1747 unsigned long flags;
1748
1749 /* get a pointer to the next message, if any */
1750 spin_lock_irqsave(&ctlr->queue_lock, flags);
1751 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1752 queue);
1753 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1754
1755 return next;
1756}
1757EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1758
1759/**
1760 * spi_finalize_current_message() - the current message is complete
1761 * @ctlr: the controller to return the message to
1762 *
1763 * Called by the driver to notify the core that the message in the front of the
1764 * queue is complete and can be removed from the queue.
1765 */
1766void spi_finalize_current_message(struct spi_controller *ctlr)
1767{
1768 struct spi_transfer *xfer;
1769 struct spi_message *mesg;
1770 unsigned long flags;
1771 int ret;
1772
1773 spin_lock_irqsave(&ctlr->queue_lock, flags);
1774 mesg = ctlr->cur_msg;
1775 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1776
1777 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1778 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
1779 ptp_read_system_postts(xfer->ptp_sts);
1780 xfer->ptp_sts_word_post = xfer->len;
1781 }
1782 }
1783
1784 if (unlikely(ctlr->ptp_sts_supported))
1785 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
1786 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
1787
1788 spi_unmap_msg(ctlr, mesg);
1789
1790 /* In the prepare_messages callback the spi bus has the opportunity to
1791 * split a transfer to smaller chunks.
1792 * Release splited transfers here since spi_map_msg is done on the
1793 * splited transfers.
1794 */
1795 spi_res_release(ctlr, mesg);
1796
1797 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1798 ret = ctlr->unprepare_message(ctlr, mesg);
1799 if (ret) {
1800 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1801 ret);
1802 }
1803 }
1804
1805 spin_lock_irqsave(&ctlr->queue_lock, flags);
1806 ctlr->cur_msg = NULL;
1807 ctlr->cur_msg_prepared = false;
1808 ctlr->fallback = false;
1809 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1810 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1811
1812 trace_spi_message_done(mesg);
1813
1814 mesg->state = NULL;
1815 if (mesg->complete)
1816 mesg->complete(mesg->context);
1817}
1818EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1819
1820static int spi_start_queue(struct spi_controller *ctlr)
1821{
1822 unsigned long flags;
1823
1824 spin_lock_irqsave(&ctlr->queue_lock, flags);
1825
1826 if (ctlr->running || ctlr->busy) {
1827 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1828 return -EBUSY;
1829 }
1830
1831 ctlr->running = true;
1832 ctlr->cur_msg = NULL;
1833 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1834
1835 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1836
1837 return 0;
1838}
1839
1840static int spi_stop_queue(struct spi_controller *ctlr)
1841{
1842 unsigned long flags;
1843 unsigned limit = 500;
1844 int ret = 0;
1845
1846 spin_lock_irqsave(&ctlr->queue_lock, flags);
1847
1848 /*
1849 * This is a bit lame, but is optimized for the common execution path.
1850 * A wait_queue on the ctlr->busy could be used, but then the common
1851 * execution path (pump_messages) would be required to call wake_up or
1852 * friends on every SPI message. Do this instead.
1853 */
1854 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1855 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1856 usleep_range(10000, 11000);
1857 spin_lock_irqsave(&ctlr->queue_lock, flags);
1858 }
1859
1860 if (!list_empty(&ctlr->queue) || ctlr->busy)
1861 ret = -EBUSY;
1862 else
1863 ctlr->running = false;
1864
1865 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1866
1867 if (ret) {
1868 dev_warn(&ctlr->dev, "could not stop message queue\n");
1869 return ret;
1870 }
1871 return ret;
1872}
1873
1874static int spi_destroy_queue(struct spi_controller *ctlr)
1875{
1876 int ret;
1877
1878 ret = spi_stop_queue(ctlr);
1879
1880 /*
1881 * kthread_flush_worker will block until all work is done.
1882 * If the reason that stop_queue timed out is that the work will never
1883 * finish, then it does no good to call flush/stop thread, so
1884 * return anyway.
1885 */
1886 if (ret) {
1887 dev_err(&ctlr->dev, "problem destroying queue\n");
1888 return ret;
1889 }
1890
1891 kthread_destroy_worker(ctlr->kworker);
1892
1893 return 0;
1894}
1895
1896static int __spi_queued_transfer(struct spi_device *spi,
1897 struct spi_message *msg,
1898 bool need_pump)
1899{
1900 struct spi_controller *ctlr = spi->controller;
1901 unsigned long flags;
1902
1903 spin_lock_irqsave(&ctlr->queue_lock, flags);
1904
1905 if (!ctlr->running) {
1906 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1907 return -ESHUTDOWN;
1908 }
1909 msg->actual_length = 0;
1910 msg->status = -EINPROGRESS;
1911
1912 list_add_tail(&msg->queue, &ctlr->queue);
1913 if (!ctlr->busy && need_pump)
1914 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1915
1916 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1917 return 0;
1918}
1919
1920/**
1921 * spi_queued_transfer - transfer function for queued transfers
1922 * @spi: spi device which is requesting transfer
1923 * @msg: spi message which is to handled is queued to driver queue
1924 *
1925 * Return: zero on success, else a negative error code.
1926 */
1927static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1928{
1929 return __spi_queued_transfer(spi, msg, true);
1930}
1931
1932static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1933{
1934 int ret;
1935
1936 ctlr->transfer = spi_queued_transfer;
1937 if (!ctlr->transfer_one_message)
1938 ctlr->transfer_one_message = spi_transfer_one_message;
1939
1940 /* Initialize and start queue */
1941 ret = spi_init_queue(ctlr);
1942 if (ret) {
1943 dev_err(&ctlr->dev, "problem initializing queue\n");
1944 goto err_init_queue;
1945 }
1946 ctlr->queued = true;
1947 ret = spi_start_queue(ctlr);
1948 if (ret) {
1949 dev_err(&ctlr->dev, "problem starting queue\n");
1950 goto err_start_queue;
1951 }
1952
1953 return 0;
1954
1955err_start_queue:
1956 spi_destroy_queue(ctlr);
1957err_init_queue:
1958 return ret;
1959}
1960
1961/**
1962 * spi_flush_queue - Send all pending messages in the queue from the callers'
1963 * context
1964 * @ctlr: controller to process queue for
1965 *
1966 * This should be used when one wants to ensure all pending messages have been
1967 * sent before doing something. Is used by the spi-mem code to make sure SPI
1968 * memory operations do not preempt regular SPI transfers that have been queued
1969 * before the spi-mem operation.
1970 */
1971void spi_flush_queue(struct spi_controller *ctlr)
1972{
1973 if (ctlr->transfer == spi_queued_transfer)
1974 __spi_pump_messages(ctlr, false);
1975}
1976
1977/*-------------------------------------------------------------------------*/
1978
1979#if defined(CONFIG_OF)
1980static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1981 struct device_node *nc)
1982{
1983 u32 value;
1984 int rc;
1985
1986 /* Mode (clock phase/polarity/etc.) */
1987 if (of_property_read_bool(nc, "spi-cpha"))
1988 spi->mode |= SPI_CPHA;
1989 if (of_property_read_bool(nc, "spi-cpol"))
1990 spi->mode |= SPI_CPOL;
1991 if (of_property_read_bool(nc, "spi-3wire"))
1992 spi->mode |= SPI_3WIRE;
1993 if (of_property_read_bool(nc, "spi-lsb-first"))
1994 spi->mode |= SPI_LSB_FIRST;
1995 if (of_property_read_bool(nc, "spi-cs-high"))
1996 spi->mode |= SPI_CS_HIGH;
1997
1998 /* Device DUAL/QUAD mode */
1999 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
2000 switch (value) {
2001 case 0:
2002 spi->mode |= SPI_NO_TX;
2003 break;
2004 case 1:
2005 break;
2006 case 2:
2007 spi->mode |= SPI_TX_DUAL;
2008 break;
2009 case 4:
2010 spi->mode |= SPI_TX_QUAD;
2011 break;
2012 case 8:
2013 spi->mode |= SPI_TX_OCTAL;
2014 break;
2015 default:
2016 dev_warn(&ctlr->dev,
2017 "spi-tx-bus-width %d not supported\n",
2018 value);
2019 break;
2020 }
2021 }
2022
2023 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
2024 switch (value) {
2025 case 0:
2026 spi->mode |= SPI_NO_RX;
2027 break;
2028 case 1:
2029 break;
2030 case 2:
2031 spi->mode |= SPI_RX_DUAL;
2032 break;
2033 case 4:
2034 spi->mode |= SPI_RX_QUAD;
2035 break;
2036 case 8:
2037 spi->mode |= SPI_RX_OCTAL;
2038 break;
2039 default:
2040 dev_warn(&ctlr->dev,
2041 "spi-rx-bus-width %d not supported\n",
2042 value);
2043 break;
2044 }
2045 }
2046
2047 if (spi_controller_is_slave(ctlr)) {
2048 if (!of_node_name_eq(nc, "slave")) {
2049 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
2050 nc);
2051 return -EINVAL;
2052 }
2053 return 0;
2054 }
2055
2056 /* Device address */
2057 rc = of_property_read_u32(nc, "reg", &value);
2058 if (rc) {
2059 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
2060 nc, rc);
2061 return rc;
2062 }
2063 spi->chip_select = value;
2064
2065 /* Device speed */
2066 if (!of_property_read_u32(nc, "spi-max-frequency", &value))
2067 spi->max_speed_hz = value;
2068
2069 return 0;
2070}
2071
2072static struct spi_device *
2073of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
2074{
2075 struct spi_device *spi;
2076 int rc;
2077
2078 /* Alloc an spi_device */
2079 spi = spi_alloc_device(ctlr);
2080 if (!spi) {
2081 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
2082 rc = -ENOMEM;
2083 goto err_out;
2084 }
2085
2086 /* Select device driver */
2087 rc = of_modalias_node(nc, spi->modalias,
2088 sizeof(spi->modalias));
2089 if (rc < 0) {
2090 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
2091 goto err_out;
2092 }
2093
2094 rc = of_spi_parse_dt(ctlr, spi, nc);
2095 if (rc)
2096 goto err_out;
2097
2098 /* Store a pointer to the node in the device structure */
2099 of_node_get(nc);
2100 spi->dev.of_node = nc;
2101 spi->dev.fwnode = of_fwnode_handle(nc);
2102
2103 /* Register the new device */
2104 rc = spi_add_device(spi);
2105 if (rc) {
2106 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
2107 goto err_of_node_put;
2108 }
2109
2110 return spi;
2111
2112err_of_node_put:
2113 of_node_put(nc);
2114err_out:
2115 spi_dev_put(spi);
2116 return ERR_PTR(rc);
2117}
2118
2119/**
2120 * of_register_spi_devices() - Register child devices onto the SPI bus
2121 * @ctlr: Pointer to spi_controller device
2122 *
2123 * Registers an spi_device for each child node of controller node which
2124 * represents a valid SPI slave.
2125 */
2126static void of_register_spi_devices(struct spi_controller *ctlr)
2127{
2128 struct spi_device *spi;
2129 struct device_node *nc;
2130
2131 if (!ctlr->dev.of_node)
2132 return;
2133
2134 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2135 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2136 continue;
2137 spi = of_register_spi_device(ctlr, nc);
2138 if (IS_ERR(spi)) {
2139 dev_warn(&ctlr->dev,
2140 "Failed to create SPI device for %pOF\n", nc);
2141 of_node_clear_flag(nc, OF_POPULATED);
2142 }
2143 }
2144}
2145#else
2146static void of_register_spi_devices(struct spi_controller *ctlr) { }
2147#endif
2148
2149/**
2150 * spi_new_ancillary_device() - Register ancillary SPI device
2151 * @spi: Pointer to the main SPI device registering the ancillary device
2152 * @chip_select: Chip Select of the ancillary device
2153 *
2154 * Register an ancillary SPI device; for example some chips have a chip-select
2155 * for normal device usage and another one for setup/firmware upload.
2156 *
2157 * This may only be called from main SPI device's probe routine.
2158 *
2159 * Return: 0 on success; negative errno on failure
2160 */
2161struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
2162 u8 chip_select)
2163{
2164 struct spi_device *ancillary;
2165 int rc = 0;
2166
2167 /* Alloc an spi_device */
2168 ancillary = spi_alloc_device(spi->controller);
2169 if (!ancillary) {
2170 rc = -ENOMEM;
2171 goto err_out;
2172 }
2173
2174 strlcpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));
2175
2176 /* Use provided chip-select for ancillary device */
2177 ancillary->chip_select = chip_select;
2178
2179 /* Take over SPI mode/speed from SPI main device */
2180 ancillary->max_speed_hz = spi->max_speed_hz;
2181 ancillary->mode = spi->mode;
2182
2183 /* Register the new device */
2184 rc = spi_add_device_locked(ancillary);
2185 if (rc) {
2186 dev_err(&spi->dev, "failed to register ancillary device\n");
2187 goto err_out;
2188 }
2189
2190 return ancillary;
2191
2192err_out:
2193 spi_dev_put(ancillary);
2194 return ERR_PTR(rc);
2195}
2196EXPORT_SYMBOL_GPL(spi_new_ancillary_device);
2197
2198#ifdef CONFIG_ACPI
2199struct acpi_spi_lookup {
2200 struct spi_controller *ctlr;
2201 u32 max_speed_hz;
2202 u32 mode;
2203 int irq;
2204 u8 bits_per_word;
2205 u8 chip_select;
2206};
2207
2208static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2209 struct acpi_spi_lookup *lookup)
2210{
2211 const union acpi_object *obj;
2212
2213 if (!x86_apple_machine)
2214 return;
2215
2216 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2217 && obj->buffer.length >= 4)
2218 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2219
2220 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2221 && obj->buffer.length == 8)
2222 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2223
2224 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2225 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2226 lookup->mode |= SPI_LSB_FIRST;
2227
2228 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2229 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2230 lookup->mode |= SPI_CPOL;
2231
2232 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2233 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2234 lookup->mode |= SPI_CPHA;
2235}
2236
2237static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2238{
2239 struct acpi_spi_lookup *lookup = data;
2240 struct spi_controller *ctlr = lookup->ctlr;
2241
2242 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2243 struct acpi_resource_spi_serialbus *sb;
2244 acpi_handle parent_handle;
2245 acpi_status status;
2246
2247 sb = &ares->data.spi_serial_bus;
2248 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2249
2250 status = acpi_get_handle(NULL,
2251 sb->resource_source.string_ptr,
2252 &parent_handle);
2253
2254 if (ACPI_FAILURE(status) ||
2255 ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
2256 return -ENODEV;
2257
2258 /*
2259 * ACPI DeviceSelection numbering is handled by the
2260 * host controller driver in Windows and can vary
2261 * from driver to driver. In Linux we always expect
2262 * 0 .. max - 1 so we need to ask the driver to
2263 * translate between the two schemes.
2264 */
2265 if (ctlr->fw_translate_cs) {
2266 int cs = ctlr->fw_translate_cs(ctlr,
2267 sb->device_selection);
2268 if (cs < 0)
2269 return cs;
2270 lookup->chip_select = cs;
2271 } else {
2272 lookup->chip_select = sb->device_selection;
2273 }
2274
2275 lookup->max_speed_hz = sb->connection_speed;
2276 lookup->bits_per_word = sb->data_bit_length;
2277
2278 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2279 lookup->mode |= SPI_CPHA;
2280 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2281 lookup->mode |= SPI_CPOL;
2282 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2283 lookup->mode |= SPI_CS_HIGH;
2284 }
2285 } else if (lookup->irq < 0) {
2286 struct resource r;
2287
2288 if (acpi_dev_resource_interrupt(ares, 0, &r))
2289 lookup->irq = r.start;
2290 }
2291
2292 /* Always tell the ACPI core to skip this resource */
2293 return 1;
2294}
2295
2296static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2297 struct acpi_device *adev)
2298{
2299 acpi_handle parent_handle = NULL;
2300 struct list_head resource_list;
2301 struct acpi_spi_lookup lookup = {};
2302 struct spi_device *spi;
2303 int ret;
2304
2305 if (acpi_bus_get_status(adev) || !adev->status.present ||
2306 acpi_device_enumerated(adev))
2307 return AE_OK;
2308
2309 lookup.ctlr = ctlr;
2310 lookup.irq = -1;
2311
2312 INIT_LIST_HEAD(&resource_list);
2313 ret = acpi_dev_get_resources(adev, &resource_list,
2314 acpi_spi_add_resource, &lookup);
2315 acpi_dev_free_resource_list(&resource_list);
2316
2317 if (ret < 0)
2318 /* found SPI in _CRS but it points to another controller */
2319 return AE_OK;
2320
2321 if (!lookup.max_speed_hz &&
2322 ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
2323 ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {
2324 /* Apple does not use _CRS but nested devices for SPI slaves */
2325 acpi_spi_parse_apple_properties(adev, &lookup);
2326 }
2327
2328 if (!lookup.max_speed_hz)
2329 return AE_OK;
2330
2331 spi = spi_alloc_device(ctlr);
2332 if (!spi) {
2333 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
2334 dev_name(&adev->dev));
2335 return AE_NO_MEMORY;
2336 }
2337
2338
2339 ACPI_COMPANION_SET(&spi->dev, adev);
2340 spi->max_speed_hz = lookup.max_speed_hz;
2341 spi->mode |= lookup.mode;
2342 spi->irq = lookup.irq;
2343 spi->bits_per_word = lookup.bits_per_word;
2344 spi->chip_select = lookup.chip_select;
2345
2346 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2347 sizeof(spi->modalias));
2348
2349 if (spi->irq < 0)
2350 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
2351
2352 acpi_device_set_enumerated(adev);
2353
2354 adev->power.flags.ignore_parent = true;
2355 if (spi_add_device(spi)) {
2356 adev->power.flags.ignore_parent = false;
2357 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2358 dev_name(&adev->dev));
2359 spi_dev_put(spi);
2360 }
2361
2362 return AE_OK;
2363}
2364
2365static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2366 void *data, void **return_value)
2367{
2368 struct spi_controller *ctlr = data;
2369 struct acpi_device *adev;
2370
2371 if (acpi_bus_get_device(handle, &adev))
2372 return AE_OK;
2373
2374 return acpi_register_spi_device(ctlr, adev);
2375}
2376
2377#define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2378
2379static void acpi_register_spi_devices(struct spi_controller *ctlr)
2380{
2381 acpi_status status;
2382 acpi_handle handle;
2383
2384 handle = ACPI_HANDLE(ctlr->dev.parent);
2385 if (!handle)
2386 return;
2387
2388 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2389 SPI_ACPI_ENUMERATE_MAX_DEPTH,
2390 acpi_spi_add_device, NULL, ctlr, NULL);
2391 if (ACPI_FAILURE(status))
2392 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2393}
2394#else
2395static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2396#endif /* CONFIG_ACPI */
2397
2398static void spi_controller_release(struct device *dev)
2399{
2400 struct spi_controller *ctlr;
2401
2402 ctlr = container_of(dev, struct spi_controller, dev);
2403 kfree(ctlr);
2404}
2405
2406static struct class spi_master_class = {
2407 .name = "spi_master",
2408 .owner = THIS_MODULE,
2409 .dev_release = spi_controller_release,
2410 .dev_groups = spi_master_groups,
2411};
2412
2413#ifdef CONFIG_SPI_SLAVE
2414/**
2415 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2416 * controller
2417 * @spi: device used for the current transfer
2418 */
2419int spi_slave_abort(struct spi_device *spi)
2420{
2421 struct spi_controller *ctlr = spi->controller;
2422
2423 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
2424 return ctlr->slave_abort(ctlr);
2425
2426 return -ENOTSUPP;
2427}
2428EXPORT_SYMBOL_GPL(spi_slave_abort);
2429
2430static int match_true(struct device *dev, void *data)
2431{
2432 return 1;
2433}
2434
2435static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2436 char *buf)
2437{
2438 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2439 dev);
2440 struct device *child;
2441
2442 child = device_find_child(&ctlr->dev, NULL, match_true);
2443 return sprintf(buf, "%s\n",
2444 child ? to_spi_device(child)->modalias : NULL);
2445}
2446
2447static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
2448 const char *buf, size_t count)
2449{
2450 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2451 dev);
2452 struct spi_device *spi;
2453 struct device *child;
2454 char name[32];
2455 int rc;
2456
2457 rc = sscanf(buf, "%31s", name);
2458 if (rc != 1 || !name[0])
2459 return -EINVAL;
2460
2461 child = device_find_child(&ctlr->dev, NULL, match_true);
2462 if (child) {
2463 /* Remove registered slave */
2464 device_unregister(child);
2465 put_device(child);
2466 }
2467
2468 if (strcmp(name, "(null)")) {
2469 /* Register new slave */
2470 spi = spi_alloc_device(ctlr);
2471 if (!spi)
2472 return -ENOMEM;
2473
2474 strlcpy(spi->modalias, name, sizeof(spi->modalias));
2475
2476 rc = spi_add_device(spi);
2477 if (rc) {
2478 spi_dev_put(spi);
2479 return rc;
2480 }
2481 }
2482
2483 return count;
2484}
2485
2486static DEVICE_ATTR_RW(slave);
2487
2488static struct attribute *spi_slave_attrs[] = {
2489 &dev_attr_slave.attr,
2490 NULL,
2491};
2492
2493static const struct attribute_group spi_slave_group = {
2494 .attrs = spi_slave_attrs,
2495};
2496
2497static const struct attribute_group *spi_slave_groups[] = {
2498 &spi_controller_statistics_group,
2499 &spi_slave_group,
2500 NULL,
2501};
2502
2503static struct class spi_slave_class = {
2504 .name = "spi_slave",
2505 .owner = THIS_MODULE,
2506 .dev_release = spi_controller_release,
2507 .dev_groups = spi_slave_groups,
2508};
2509#else
2510extern struct class spi_slave_class; /* dummy */
2511#endif
2512
2513/**
2514 * __spi_alloc_controller - allocate an SPI master or slave controller
2515 * @dev: the controller, possibly using the platform_bus
2516 * @size: how much zeroed driver-private data to allocate; the pointer to this
2517 * memory is in the driver_data field of the returned device, accessible
2518 * with spi_controller_get_devdata(); the memory is cacheline aligned;
2519 * drivers granting DMA access to portions of their private data need to
2520 * round up @size using ALIGN(size, dma_get_cache_alignment()).
2521 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2522 * slave (true) controller
2523 * Context: can sleep
2524 *
2525 * This call is used only by SPI controller drivers, which are the
2526 * only ones directly touching chip registers. It's how they allocate
2527 * an spi_controller structure, prior to calling spi_register_controller().
2528 *
2529 * This must be called from context that can sleep.
2530 *
2531 * The caller is responsible for assigning the bus number and initializing the
2532 * controller's methods before calling spi_register_controller(); and (after
2533 * errors adding the device) calling spi_controller_put() to prevent a memory
2534 * leak.
2535 *
2536 * Return: the SPI controller structure on success, else NULL.
2537 */
2538struct spi_controller *__spi_alloc_controller(struct device *dev,
2539 unsigned int size, bool slave)
2540{
2541 struct spi_controller *ctlr;
2542 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
2543
2544 if (!dev)
2545 return NULL;
2546
2547 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
2548 if (!ctlr)
2549 return NULL;
2550
2551 device_initialize(&ctlr->dev);
2552 INIT_LIST_HEAD(&ctlr->queue);
2553 spin_lock_init(&ctlr->queue_lock);
2554 spin_lock_init(&ctlr->bus_lock_spinlock);
2555 mutex_init(&ctlr->bus_lock_mutex);
2556 mutex_init(&ctlr->io_mutex);
2557 mutex_init(&ctlr->add_lock);
2558 ctlr->bus_num = -1;
2559 ctlr->num_chipselect = 1;
2560 ctlr->slave = slave;
2561 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2562 ctlr->dev.class = &spi_slave_class;
2563 else
2564 ctlr->dev.class = &spi_master_class;
2565 ctlr->dev.parent = dev;
2566 pm_suspend_ignore_children(&ctlr->dev, true);
2567 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
2568
2569 return ctlr;
2570}
2571EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2572
2573static void devm_spi_release_controller(struct device *dev, void *ctlr)
2574{
2575 spi_controller_put(*(struct spi_controller **)ctlr);
2576}
2577
2578/**
2579 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
2580 * @dev: physical device of SPI controller
2581 * @size: how much zeroed driver-private data to allocate
2582 * @slave: whether to allocate an SPI master (false) or SPI slave (true)
2583 * Context: can sleep
2584 *
2585 * Allocate an SPI controller and automatically release a reference on it
2586 * when @dev is unbound from its driver. Drivers are thus relieved from
2587 * having to call spi_controller_put().
2588 *
2589 * The arguments to this function are identical to __spi_alloc_controller().
2590 *
2591 * Return: the SPI controller structure on success, else NULL.
2592 */
2593struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
2594 unsigned int size,
2595 bool slave)
2596{
2597 struct spi_controller **ptr, *ctlr;
2598
2599 ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),
2600 GFP_KERNEL);
2601 if (!ptr)
2602 return NULL;
2603
2604 ctlr = __spi_alloc_controller(dev, size, slave);
2605 if (ctlr) {
2606 ctlr->devm_allocated = true;
2607 *ptr = ctlr;
2608 devres_add(dev, ptr);
2609 } else {
2610 devres_free(ptr);
2611 }
2612
2613 return ctlr;
2614}
2615EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);
2616
2617#ifdef CONFIG_OF
2618static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2619{
2620 int nb, i, *cs;
2621 struct device_node *np = ctlr->dev.of_node;
2622
2623 if (!np)
2624 return 0;
2625
2626 nb = of_gpio_named_count(np, "cs-gpios");
2627 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2628
2629 /* Return error only for an incorrectly formed cs-gpios property */
2630 if (nb == 0 || nb == -ENOENT)
2631 return 0;
2632 else if (nb < 0)
2633 return nb;
2634
2635 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2636 GFP_KERNEL);
2637 ctlr->cs_gpios = cs;
2638
2639 if (!ctlr->cs_gpios)
2640 return -ENOMEM;
2641
2642 for (i = 0; i < ctlr->num_chipselect; i++)
2643 cs[i] = -ENOENT;
2644
2645 for (i = 0; i < nb; i++)
2646 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2647
2648 return 0;
2649}
2650#else
2651static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2652{
2653 return 0;
2654}
2655#endif
2656
2657/**
2658 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2659 * @ctlr: The SPI master to grab GPIO descriptors for
2660 */
2661static int spi_get_gpio_descs(struct spi_controller *ctlr)
2662{
2663 int nb, i;
2664 struct gpio_desc **cs;
2665 struct device *dev = &ctlr->dev;
2666 unsigned long native_cs_mask = 0;
2667 unsigned int num_cs_gpios = 0;
2668
2669 nb = gpiod_count(dev, "cs");
2670 if (nb < 0) {
2671 /* No GPIOs at all is fine, else return the error */
2672 if (nb == -ENOENT)
2673 return 0;
2674 return nb;
2675 }
2676
2677 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2678
2679 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
2680 GFP_KERNEL);
2681 if (!cs)
2682 return -ENOMEM;
2683 ctlr->cs_gpiods = cs;
2684
2685 for (i = 0; i < nb; i++) {
2686 /*
2687 * Most chipselects are active low, the inverted
2688 * semantics are handled by special quirks in gpiolib,
2689 * so initializing them GPIOD_OUT_LOW here means
2690 * "unasserted", in most cases this will drive the physical
2691 * line high.
2692 */
2693 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
2694 GPIOD_OUT_LOW);
2695 if (IS_ERR(cs[i]))
2696 return PTR_ERR(cs[i]);
2697
2698 if (cs[i]) {
2699 /*
2700 * If we find a CS GPIO, name it after the device and
2701 * chip select line.
2702 */
2703 char *gpioname;
2704
2705 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
2706 dev_name(dev), i);
2707 if (!gpioname)
2708 return -ENOMEM;
2709 gpiod_set_consumer_name(cs[i], gpioname);
2710 num_cs_gpios++;
2711 continue;
2712 }
2713
2714 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
2715 dev_err(dev, "Invalid native chip select %d\n", i);
2716 return -EINVAL;
2717 }
2718 native_cs_mask |= BIT(i);
2719 }
2720
2721 ctlr->unused_native_cs = ffs(~native_cs_mask) - 1;
2722
2723 if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios &&
2724 ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {
2725 dev_err(dev, "No unused native chip select available\n");
2726 return -EINVAL;
2727 }
2728
2729 return 0;
2730}
2731
2732static int spi_controller_check_ops(struct spi_controller *ctlr)
2733{
2734 /*
2735 * The controller may implement only the high-level SPI-memory like
2736 * operations if it does not support regular SPI transfers, and this is
2737 * valid use case.
2738 * If ->mem_ops is NULL, we request that at least one of the
2739 * ->transfer_xxx() method be implemented.
2740 */
2741 if (ctlr->mem_ops) {
2742 if (!ctlr->mem_ops->exec_op)
2743 return -EINVAL;
2744 } else if (!ctlr->transfer && !ctlr->transfer_one &&
2745 !ctlr->transfer_one_message) {
2746 return -EINVAL;
2747 }
2748
2749 return 0;
2750}
2751
2752/**
2753 * spi_register_controller - register SPI master or slave controller
2754 * @ctlr: initialized master, originally from spi_alloc_master() or
2755 * spi_alloc_slave()
2756 * Context: can sleep
2757 *
2758 * SPI controllers connect to their drivers using some non-SPI bus,
2759 * such as the platform bus. The final stage of probe() in that code
2760 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2761 *
2762 * SPI controllers use board specific (often SOC specific) bus numbers,
2763 * and board-specific addressing for SPI devices combines those numbers
2764 * with chip select numbers. Since SPI does not directly support dynamic
2765 * device identification, boards need configuration tables telling which
2766 * chip is at which address.
2767 *
2768 * This must be called from context that can sleep. It returns zero on
2769 * success, else a negative error code (dropping the controller's refcount).
2770 * After a successful return, the caller is responsible for calling
2771 * spi_unregister_controller().
2772 *
2773 * Return: zero on success, else a negative error code.
2774 */
2775int spi_register_controller(struct spi_controller *ctlr)
2776{
2777 struct device *dev = ctlr->dev.parent;
2778 struct boardinfo *bi;
2779 int status;
2780 int id, first_dynamic;
2781
2782 if (!dev)
2783 return -ENODEV;
2784
2785 /*
2786 * Make sure all necessary hooks are implemented before registering
2787 * the SPI controller.
2788 */
2789 status = spi_controller_check_ops(ctlr);
2790 if (status)
2791 return status;
2792
2793 if (ctlr->bus_num >= 0) {
2794 /* devices with a fixed bus num must check-in with the num */
2795 mutex_lock(&board_lock);
2796 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2797 ctlr->bus_num + 1, GFP_KERNEL);
2798 mutex_unlock(&board_lock);
2799 if (WARN(id < 0, "couldn't get idr"))
2800 return id == -ENOSPC ? -EBUSY : id;
2801 ctlr->bus_num = id;
2802 } else if (ctlr->dev.of_node) {
2803 /* allocate dynamic bus number using Linux idr */
2804 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2805 if (id >= 0) {
2806 ctlr->bus_num = id;
2807 mutex_lock(&board_lock);
2808 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2809 ctlr->bus_num + 1, GFP_KERNEL);
2810 mutex_unlock(&board_lock);
2811 if (WARN(id < 0, "couldn't get idr"))
2812 return id == -ENOSPC ? -EBUSY : id;
2813 }
2814 }
2815 if (ctlr->bus_num < 0) {
2816 first_dynamic = of_alias_get_highest_id("spi");
2817 if (first_dynamic < 0)
2818 first_dynamic = 0;
2819 else
2820 first_dynamic++;
2821
2822 mutex_lock(&board_lock);
2823 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2824 0, GFP_KERNEL);
2825 mutex_unlock(&board_lock);
2826 if (WARN(id < 0, "couldn't get idr"))
2827 return id;
2828 ctlr->bus_num = id;
2829 }
2830 ctlr->bus_lock_flag = 0;
2831 init_completion(&ctlr->xfer_completion);
2832 if (!ctlr->max_dma_len)
2833 ctlr->max_dma_len = INT_MAX;
2834
2835 /* register the device, then userspace will see it.
2836 * registration fails if the bus ID is in use.
2837 */
2838 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2839
2840 if (!spi_controller_is_slave(ctlr)) {
2841 if (ctlr->use_gpio_descriptors) {
2842 status = spi_get_gpio_descs(ctlr);
2843 if (status)
2844 goto free_bus_id;
2845 /*
2846 * A controller using GPIO descriptors always
2847 * supports SPI_CS_HIGH if need be.
2848 */
2849 ctlr->mode_bits |= SPI_CS_HIGH;
2850 } else {
2851 /* Legacy code path for GPIOs from DT */
2852 status = of_spi_get_gpio_numbers(ctlr);
2853 if (status)
2854 goto free_bus_id;
2855 }
2856 }
2857
2858 /*
2859 * Even if it's just one always-selected device, there must
2860 * be at least one chipselect.
2861 */
2862 if (!ctlr->num_chipselect) {
2863 status = -EINVAL;
2864 goto free_bus_id;
2865 }
2866
2867 status = device_add(&ctlr->dev);
2868 if (status < 0)
2869 goto free_bus_id;
2870 dev_dbg(dev, "registered %s %s\n",
2871 spi_controller_is_slave(ctlr) ? "slave" : "master",
2872 dev_name(&ctlr->dev));
2873
2874 /*
2875 * If we're using a queued driver, start the queue. Note that we don't
2876 * need the queueing logic if the driver is only supporting high-level
2877 * memory operations.
2878 */
2879 if (ctlr->transfer) {
2880 dev_info(dev, "controller is unqueued, this is deprecated\n");
2881 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2882 status = spi_controller_initialize_queue(ctlr);
2883 if (status) {
2884 device_del(&ctlr->dev);
2885 goto free_bus_id;
2886 }
2887 }
2888 /* add statistics */
2889 spin_lock_init(&ctlr->statistics.lock);
2890
2891 mutex_lock(&board_lock);
2892 list_add_tail(&ctlr->list, &spi_controller_list);
2893 list_for_each_entry(bi, &board_list, list)
2894 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2895 mutex_unlock(&board_lock);
2896
2897 /* Register devices from the device tree and ACPI */
2898 of_register_spi_devices(ctlr);
2899 acpi_register_spi_devices(ctlr);
2900 return status;
2901
2902free_bus_id:
2903 mutex_lock(&board_lock);
2904 idr_remove(&spi_master_idr, ctlr->bus_num);
2905 mutex_unlock(&board_lock);
2906 return status;
2907}
2908EXPORT_SYMBOL_GPL(spi_register_controller);
2909
2910static void devm_spi_unregister(void *ctlr)
2911{
2912 spi_unregister_controller(ctlr);
2913}
2914
2915/**
2916 * devm_spi_register_controller - register managed SPI master or slave
2917 * controller
2918 * @dev: device managing SPI controller
2919 * @ctlr: initialized controller, originally from spi_alloc_master() or
2920 * spi_alloc_slave()
2921 * Context: can sleep
2922 *
2923 * Register a SPI device as with spi_register_controller() which will
2924 * automatically be unregistered and freed.
2925 *
2926 * Return: zero on success, else a negative error code.
2927 */
2928int devm_spi_register_controller(struct device *dev,
2929 struct spi_controller *ctlr)
2930{
2931 int ret;
2932
2933 ret = spi_register_controller(ctlr);
2934 if (ret)
2935 return ret;
2936
2937 return devm_add_action_or_reset(dev, devm_spi_unregister, ctlr);
2938}
2939EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2940
2941static int __unregister(struct device *dev, void *null)
2942{
2943 spi_unregister_device(to_spi_device(dev));
2944 return 0;
2945}
2946
2947/**
2948 * spi_unregister_controller - unregister SPI master or slave controller
2949 * @ctlr: the controller being unregistered
2950 * Context: can sleep
2951 *
2952 * This call is used only by SPI controller drivers, which are the
2953 * only ones directly touching chip registers.
2954 *
2955 * This must be called from context that can sleep.
2956 *
2957 * Note that this function also drops a reference to the controller.
2958 */
2959void spi_unregister_controller(struct spi_controller *ctlr)
2960{
2961 struct spi_controller *found;
2962 int id = ctlr->bus_num;
2963
2964 /* Prevent addition of new devices, unregister existing ones */
2965 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2966 mutex_lock(&ctlr->add_lock);
2967
2968 device_for_each_child(&ctlr->dev, NULL, __unregister);
2969
2970 /* First make sure that this controller was ever added */
2971 mutex_lock(&board_lock);
2972 found = idr_find(&spi_master_idr, id);
2973 mutex_unlock(&board_lock);
2974 if (ctlr->queued) {
2975 if (spi_destroy_queue(ctlr))
2976 dev_err(&ctlr->dev, "queue remove failed\n");
2977 }
2978 mutex_lock(&board_lock);
2979 list_del(&ctlr->list);
2980 mutex_unlock(&board_lock);
2981
2982 device_del(&ctlr->dev);
2983
2984 /* Release the last reference on the controller if its driver
2985 * has not yet been converted to devm_spi_alloc_master/slave().
2986 */
2987 if (!ctlr->devm_allocated)
2988 put_device(&ctlr->dev);
2989
2990 /* free bus id */
2991 mutex_lock(&board_lock);
2992 if (found == ctlr)
2993 idr_remove(&spi_master_idr, id);
2994 mutex_unlock(&board_lock);
2995
2996 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2997 mutex_unlock(&ctlr->add_lock);
2998}
2999EXPORT_SYMBOL_GPL(spi_unregister_controller);
3000
3001int spi_controller_suspend(struct spi_controller *ctlr)
3002{
3003 int ret;
3004
3005 /* Basically no-ops for non-queued controllers */
3006 if (!ctlr->queued)
3007 return 0;
3008
3009 ret = spi_stop_queue(ctlr);
3010 if (ret)
3011 dev_err(&ctlr->dev, "queue stop failed\n");
3012
3013 return ret;
3014}
3015EXPORT_SYMBOL_GPL(spi_controller_suspend);
3016
3017int spi_controller_resume(struct spi_controller *ctlr)
3018{
3019 int ret;
3020
3021 if (!ctlr->queued)
3022 return 0;
3023
3024 ret = spi_start_queue(ctlr);
3025 if (ret)
3026 dev_err(&ctlr->dev, "queue restart failed\n");
3027
3028 return ret;
3029}
3030EXPORT_SYMBOL_GPL(spi_controller_resume);
3031
3032static int __spi_controller_match(struct device *dev, const void *data)
3033{
3034 struct spi_controller *ctlr;
3035 const u16 *bus_num = data;
3036
3037 ctlr = container_of(dev, struct spi_controller, dev);
3038 return ctlr->bus_num == *bus_num;
3039}
3040
3041/**
3042 * spi_busnum_to_master - look up master associated with bus_num
3043 * @bus_num: the master's bus number
3044 * Context: can sleep
3045 *
3046 * This call may be used with devices that are registered after
3047 * arch init time. It returns a refcounted pointer to the relevant
3048 * spi_controller (which the caller must release), or NULL if there is
3049 * no such master registered.
3050 *
3051 * Return: the SPI master structure on success, else NULL.
3052 */
3053struct spi_controller *spi_busnum_to_master(u16 bus_num)
3054{
3055 struct device *dev;
3056 struct spi_controller *ctlr = NULL;
3057
3058 dev = class_find_device(&spi_master_class, NULL, &bus_num,
3059 __spi_controller_match);
3060 if (dev)
3061 ctlr = container_of(dev, struct spi_controller, dev);
3062 /* reference got in class_find_device */
3063 return ctlr;
3064}
3065EXPORT_SYMBOL_GPL(spi_busnum_to_master);
3066
3067/*-------------------------------------------------------------------------*/
3068
3069/* Core methods for SPI resource management */
3070
3071/**
3072 * spi_res_alloc - allocate a spi resource that is life-cycle managed
3073 * during the processing of a spi_message while using
3074 * spi_transfer_one
3075 * @spi: the spi device for which we allocate memory
3076 * @release: the release code to execute for this resource
3077 * @size: size to alloc and return
3078 * @gfp: GFP allocation flags
3079 *
3080 * Return: the pointer to the allocated data
3081 *
3082 * This may get enhanced in the future to allocate from a memory pool
3083 * of the @spi_device or @spi_controller to avoid repeated allocations.
3084 */
3085void *spi_res_alloc(struct spi_device *spi,
3086 spi_res_release_t release,
3087 size_t size, gfp_t gfp)
3088{
3089 struct spi_res *sres;
3090
3091 sres = kzalloc(sizeof(*sres) + size, gfp);
3092 if (!sres)
3093 return NULL;
3094
3095 INIT_LIST_HEAD(&sres->entry);
3096 sres->release = release;
3097
3098 return sres->data;
3099}
3100EXPORT_SYMBOL_GPL(spi_res_alloc);
3101
3102/**
3103 * spi_res_free - free an spi resource
3104 * @res: pointer to the custom data of a resource
3105 *
3106 */
3107void spi_res_free(void *res)
3108{
3109 struct spi_res *sres = container_of(res, struct spi_res, data);
3110
3111 if (!res)
3112 return;
3113
3114 WARN_ON(!list_empty(&sres->entry));
3115 kfree(sres);
3116}
3117EXPORT_SYMBOL_GPL(spi_res_free);
3118
3119/**
3120 * spi_res_add - add a spi_res to the spi_message
3121 * @message: the spi message
3122 * @res: the spi_resource
3123 */
3124void spi_res_add(struct spi_message *message, void *res)
3125{
3126 struct spi_res *sres = container_of(res, struct spi_res, data);
3127
3128 WARN_ON(!list_empty(&sres->entry));
3129 list_add_tail(&sres->entry, &message->resources);
3130}
3131EXPORT_SYMBOL_GPL(spi_res_add);
3132
3133/**
3134 * spi_res_release - release all spi resources for this message
3135 * @ctlr: the @spi_controller
3136 * @message: the @spi_message
3137 */
3138void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
3139{
3140 struct spi_res *res, *tmp;
3141
3142 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
3143 if (res->release)
3144 res->release(ctlr, message, res->data);
3145
3146 list_del(&res->entry);
3147
3148 kfree(res);
3149 }
3150}
3151EXPORT_SYMBOL_GPL(spi_res_release);
3152
3153/*-------------------------------------------------------------------------*/
3154
3155/* Core methods for spi_message alterations */
3156
3157static void __spi_replace_transfers_release(struct spi_controller *ctlr,
3158 struct spi_message *msg,
3159 void *res)
3160{
3161 struct spi_replaced_transfers *rxfer = res;
3162 size_t i;
3163
3164 /* call extra callback if requested */
3165 if (rxfer->release)
3166 rxfer->release(ctlr, msg, res);
3167
3168 /* insert replaced transfers back into the message */
3169 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
3170
3171 /* remove the formerly inserted entries */
3172 for (i = 0; i < rxfer->inserted; i++)
3173 list_del(&rxfer->inserted_transfers[i].transfer_list);
3174}
3175
3176/**
3177 * spi_replace_transfers - replace transfers with several transfers
3178 * and register change with spi_message.resources
3179 * @msg: the spi_message we work upon
3180 * @xfer_first: the first spi_transfer we want to replace
3181 * @remove: number of transfers to remove
3182 * @insert: the number of transfers we want to insert instead
3183 * @release: extra release code necessary in some circumstances
3184 * @extradatasize: extra data to allocate (with alignment guarantees
3185 * of struct @spi_transfer)
3186 * @gfp: gfp flags
3187 *
3188 * Returns: pointer to @spi_replaced_transfers,
3189 * PTR_ERR(...) in case of errors.
3190 */
3191struct spi_replaced_transfers *spi_replace_transfers(
3192 struct spi_message *msg,
3193 struct spi_transfer *xfer_first,
3194 size_t remove,
3195 size_t insert,
3196 spi_replaced_release_t release,
3197 size_t extradatasize,
3198 gfp_t gfp)
3199{
3200 struct spi_replaced_transfers *rxfer;
3201 struct spi_transfer *xfer;
3202 size_t i;
3203
3204 /* allocate the structure using spi_res */
3205 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
3206 struct_size(rxfer, inserted_transfers, insert)
3207 + extradatasize,
3208 gfp);
3209 if (!rxfer)
3210 return ERR_PTR(-ENOMEM);
3211
3212 /* the release code to invoke before running the generic release */
3213 rxfer->release = release;
3214
3215 /* assign extradata */
3216 if (extradatasize)
3217 rxfer->extradata =
3218 &rxfer->inserted_transfers[insert];
3219
3220 /* init the replaced_transfers list */
3221 INIT_LIST_HEAD(&rxfer->replaced_transfers);
3222
3223 /* assign the list_entry after which we should reinsert
3224 * the @replaced_transfers - it may be spi_message.messages!
3225 */
3226 rxfer->replaced_after = xfer_first->transfer_list.prev;
3227
3228 /* remove the requested number of transfers */
3229 for (i = 0; i < remove; i++) {
3230 /* if the entry after replaced_after it is msg->transfers
3231 * then we have been requested to remove more transfers
3232 * than are in the list
3233 */
3234 if (rxfer->replaced_after->next == &msg->transfers) {
3235 dev_err(&msg->spi->dev,
3236 "requested to remove more spi_transfers than are available\n");
3237 /* insert replaced transfers back into the message */
3238 list_splice(&rxfer->replaced_transfers,
3239 rxfer->replaced_after);
3240
3241 /* free the spi_replace_transfer structure */
3242 spi_res_free(rxfer);
3243
3244 /* and return with an error */
3245 return ERR_PTR(-EINVAL);
3246 }
3247
3248 /* remove the entry after replaced_after from list of
3249 * transfers and add it to list of replaced_transfers
3250 */
3251 list_move_tail(rxfer->replaced_after->next,
3252 &rxfer->replaced_transfers);
3253 }
3254
3255 /* create copy of the given xfer with identical settings
3256 * based on the first transfer to get removed
3257 */
3258 for (i = 0; i < insert; i++) {
3259 /* we need to run in reverse order */
3260 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3261
3262 /* copy all spi_transfer data */
3263 memcpy(xfer, xfer_first, sizeof(*xfer));
3264
3265 /* add to list */
3266 list_add(&xfer->transfer_list, rxfer->replaced_after);
3267
3268 /* clear cs_change and delay for all but the last */
3269 if (i) {
3270 xfer->cs_change = false;
3271 xfer->delay.value = 0;
3272 }
3273 }
3274
3275 /* set up inserted */
3276 rxfer->inserted = insert;
3277
3278 /* and register it with spi_res/spi_message */
3279 spi_res_add(msg, rxfer);
3280
3281 return rxfer;
3282}
3283EXPORT_SYMBOL_GPL(spi_replace_transfers);
3284
3285static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3286 struct spi_message *msg,
3287 struct spi_transfer **xferp,
3288 size_t maxsize,
3289 gfp_t gfp)
3290{
3291 struct spi_transfer *xfer = *xferp, *xfers;
3292 struct spi_replaced_transfers *srt;
3293 size_t offset;
3294 size_t count, i;
3295
3296 /* calculate how many we have to replace */
3297 count = DIV_ROUND_UP(xfer->len, maxsize);
3298
3299 /* create replacement */
3300 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
3301 if (IS_ERR(srt))
3302 return PTR_ERR(srt);
3303 xfers = srt->inserted_transfers;
3304
3305 /* now handle each of those newly inserted spi_transfers
3306 * note that the replacements spi_transfers all are preset
3307 * to the same values as *xferp, so tx_buf, rx_buf and len
3308 * are all identical (as well as most others)
3309 * so we just have to fix up len and the pointers.
3310 *
3311 * this also includes support for the depreciated
3312 * spi_message.is_dma_mapped interface
3313 */
3314
3315 /* the first transfer just needs the length modified, so we
3316 * run it outside the loop
3317 */
3318 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3319
3320 /* all the others need rx_buf/tx_buf also set */
3321 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3322 /* update rx_buf, tx_buf and dma */
3323 if (xfers[i].rx_buf)
3324 xfers[i].rx_buf += offset;
3325 if (xfers[i].rx_dma)
3326 xfers[i].rx_dma += offset;
3327 if (xfers[i].tx_buf)
3328 xfers[i].tx_buf += offset;
3329 if (xfers[i].tx_dma)
3330 xfers[i].tx_dma += offset;
3331
3332 /* update length */
3333 xfers[i].len = min(maxsize, xfers[i].len - offset);
3334 }
3335
3336 /* we set up xferp to the last entry we have inserted,
3337 * so that we skip those already split transfers
3338 */
3339 *xferp = &xfers[count - 1];
3340
3341 /* increment statistics counters */
3342 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3343 transfers_split_maxsize);
3344 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
3345 transfers_split_maxsize);
3346
3347 return 0;
3348}
3349
3350/**
3351 * spi_split_transfers_maxsize - split spi transfers into multiple transfers
3352 * when an individual transfer exceeds a
3353 * certain size
3354 * @ctlr: the @spi_controller for this transfer
3355 * @msg: the @spi_message to transform
3356 * @maxsize: the maximum when to apply this
3357 * @gfp: GFP allocation flags
3358 *
3359 * Return: status of transformation
3360 */
3361int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3362 struct spi_message *msg,
3363 size_t maxsize,
3364 gfp_t gfp)
3365{
3366 struct spi_transfer *xfer;
3367 int ret;
3368
3369 /* iterate over the transfer_list,
3370 * but note that xfer is advanced to the last transfer inserted
3371 * to avoid checking sizes again unnecessarily (also xfer does
3372 * potentiall belong to a different list by the time the
3373 * replacement has happened
3374 */
3375 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3376 if (xfer->len > maxsize) {
3377 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3378 maxsize, gfp);
3379 if (ret)
3380 return ret;
3381 }
3382 }
3383
3384 return 0;
3385}
3386EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3387
3388/*-------------------------------------------------------------------------*/
3389
3390/* Core methods for SPI controller protocol drivers. Some of the
3391 * other core methods are currently defined as inline functions.
3392 */
3393
3394static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3395 u8 bits_per_word)
3396{
3397 if (ctlr->bits_per_word_mask) {
3398 /* Only 32 bits fit in the mask */
3399 if (bits_per_word > 32)
3400 return -EINVAL;
3401 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3402 return -EINVAL;
3403 }
3404
3405 return 0;
3406}
3407
3408/**
3409 * spi_setup - setup SPI mode and clock rate
3410 * @spi: the device whose settings are being modified
3411 * Context: can sleep, and no requests are queued to the device
3412 *
3413 * SPI protocol drivers may need to update the transfer mode if the
3414 * device doesn't work with its default. They may likewise need
3415 * to update clock rates or word sizes from initial values. This function
3416 * changes those settings, and must be called from a context that can sleep.
3417 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3418 * effect the next time the device is selected and data is transferred to
3419 * or from it. When this function returns, the spi device is deselected.
3420 *
3421 * Note that this call will fail if the protocol driver specifies an option
3422 * that the underlying controller or its driver does not support. For
3423 * example, not all hardware supports wire transfers using nine bit words,
3424 * LSB-first wire encoding, or active-high chipselects.
3425 *
3426 * Return: zero on success, else a negative error code.
3427 */
3428int spi_setup(struct spi_device *spi)
3429{
3430 unsigned bad_bits, ugly_bits;
3431 int status;
3432
3433 /*
3434 * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
3435 * are set at the same time
3436 */
3437 if ((hweight_long(spi->mode &
3438 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
3439 (hweight_long(spi->mode &
3440 (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
3441 dev_err(&spi->dev,
3442 "setup: can not select any two of dual, quad and no-rx/tx at the same time\n");
3443 return -EINVAL;
3444 }
3445 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
3446 */
3447 if ((spi->mode & SPI_3WIRE) && (spi->mode &
3448 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3449 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3450 return -EINVAL;
3451 /* help drivers fail *cleanly* when they need options
3452 * that aren't supported with their current controller
3453 * SPI_CS_WORD has a fallback software implementation,
3454 * so it is ignored here.
3455 */
3456 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
3457 SPI_NO_TX | SPI_NO_RX);
3458 /* nothing prevents from working with active-high CS in case if it
3459 * is driven by GPIO.
3460 */
3461 if (gpio_is_valid(spi->cs_gpio))
3462 bad_bits &= ~SPI_CS_HIGH;
3463 ugly_bits = bad_bits &
3464 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3465 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3466 if (ugly_bits) {
3467 dev_warn(&spi->dev,
3468 "setup: ignoring unsupported mode bits %x\n",
3469 ugly_bits);
3470 spi->mode &= ~ugly_bits;
3471 bad_bits &= ~ugly_bits;
3472 }
3473 if (bad_bits) {
3474 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3475 bad_bits);
3476 return -EINVAL;
3477 }
3478
3479 if (!spi->bits_per_word)
3480 spi->bits_per_word = 8;
3481
3482 status = __spi_validate_bits_per_word(spi->controller,
3483 spi->bits_per_word);
3484 if (status)
3485 return status;
3486
3487 if (spi->controller->max_speed_hz &&
3488 (!spi->max_speed_hz ||
3489 spi->max_speed_hz > spi->controller->max_speed_hz))
3490 spi->max_speed_hz = spi->controller->max_speed_hz;
3491
3492 mutex_lock(&spi->controller->io_mutex);
3493
3494 if (spi->controller->setup) {
3495 status = spi->controller->setup(spi);
3496 if (status) {
3497 mutex_unlock(&spi->controller->io_mutex);
3498 dev_err(&spi->controller->dev, "Failed to setup device: %d\n",
3499 status);
3500 return status;
3501 }
3502 }
3503
3504 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
3505 status = pm_runtime_get_sync(spi->controller->dev.parent);
3506 if (status < 0) {
3507 mutex_unlock(&spi->controller->io_mutex);
3508 pm_runtime_put_noidle(spi->controller->dev.parent);
3509 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3510 status);
3511 return status;
3512 }
3513
3514 /*
3515 * We do not want to return positive value from pm_runtime_get,
3516 * there are many instances of devices calling spi_setup() and
3517 * checking for a non-zero return value instead of a negative
3518 * return value.
3519 */
3520 status = 0;
3521
3522 spi_set_cs(spi, false, true);
3523 pm_runtime_mark_last_busy(spi->controller->dev.parent);
3524 pm_runtime_put_autosuspend(spi->controller->dev.parent);
3525 } else {
3526 spi_set_cs(spi, false, true);
3527 }
3528
3529 mutex_unlock(&spi->controller->io_mutex);
3530
3531 if (spi->rt && !spi->controller->rt) {
3532 spi->controller->rt = true;
3533 spi_set_thread_rt(spi->controller);
3534 }
3535
3536 trace_spi_setup(spi, status);
3537
3538 dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3539 spi->mode & SPI_MODE_X_MASK,
3540 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
3541 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
3542 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
3543 (spi->mode & SPI_LOOP) ? "loopback, " : "",
3544 spi->bits_per_word, spi->max_speed_hz,
3545 status);
3546
3547 return status;
3548}
3549EXPORT_SYMBOL_GPL(spi_setup);
3550
3551static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
3552 struct spi_device *spi)
3553{
3554 int delay1, delay2;
3555
3556 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
3557 if (delay1 < 0)
3558 return delay1;
3559
3560 delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
3561 if (delay2 < 0)
3562 return delay2;
3563
3564 if (delay1 < delay2)
3565 memcpy(&xfer->word_delay, &spi->word_delay,
3566 sizeof(xfer->word_delay));
3567
3568 return 0;
3569}
3570
3571static int __spi_validate(struct spi_device *spi, struct spi_message *message)
3572{
3573 struct spi_controller *ctlr = spi->controller;
3574 struct spi_transfer *xfer;
3575 int w_size;
3576
3577 if (list_empty(&message->transfers))
3578 return -EINVAL;
3579
3580 /* If an SPI controller does not support toggling the CS line on each
3581 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3582 * for the CS line, we can emulate the CS-per-word hardware function by
3583 * splitting transfers into one-word transfers and ensuring that
3584 * cs_change is set for each transfer.
3585 */
3586 if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
3587 spi->cs_gpiod ||
3588 gpio_is_valid(spi->cs_gpio))) {
3589 size_t maxsize;
3590 int ret;
3591
3592 maxsize = (spi->bits_per_word + 7) / 8;
3593
3594 /* spi_split_transfers_maxsize() requires message->spi */
3595 message->spi = spi;
3596
3597 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
3598 GFP_KERNEL);
3599 if (ret)
3600 return ret;
3601
3602 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3603 /* don't change cs_change on the last entry in the list */
3604 if (list_is_last(&xfer->transfer_list, &message->transfers))
3605 break;
3606 xfer->cs_change = 1;
3607 }
3608 }
3609
3610 /* Half-duplex links include original MicroWire, and ones with
3611 * only one data pin like SPI_3WIRE (switches direction) or where
3612 * either MOSI or MISO is missing. They can also be caused by
3613 * software limitations.
3614 */
3615 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
3616 (spi->mode & SPI_3WIRE)) {
3617 unsigned flags = ctlr->flags;
3618
3619 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3620 if (xfer->rx_buf && xfer->tx_buf)
3621 return -EINVAL;
3622 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
3623 return -EINVAL;
3624 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
3625 return -EINVAL;
3626 }
3627 }
3628
3629 /**
3630 * Set transfer bits_per_word and max speed as spi device default if
3631 * it is not set for this transfer.
3632 * Set transfer tx_nbits and rx_nbits as single transfer default
3633 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3634 * Ensure transfer word_delay is at least as long as that required by
3635 * device itself.
3636 */
3637 message->frame_length = 0;
3638 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3639 xfer->effective_speed_hz = 0;
3640 message->frame_length += xfer->len;
3641 if (!xfer->bits_per_word)
3642 xfer->bits_per_word = spi->bits_per_word;
3643
3644 if (!xfer->speed_hz)
3645 xfer->speed_hz = spi->max_speed_hz;
3646
3647 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
3648 xfer->speed_hz = ctlr->max_speed_hz;
3649
3650 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
3651 return -EINVAL;
3652
3653 /*
3654 * SPI transfer length should be multiple of SPI word size
3655 * where SPI word size should be power-of-two multiple
3656 */
3657 if (xfer->bits_per_word <= 8)
3658 w_size = 1;
3659 else if (xfer->bits_per_word <= 16)
3660 w_size = 2;
3661 else
3662 w_size = 4;
3663
3664 /* No partial transfers accepted */
3665 if (xfer->len % w_size)
3666 return -EINVAL;
3667
3668 if (xfer->speed_hz && ctlr->min_speed_hz &&
3669 xfer->speed_hz < ctlr->min_speed_hz)
3670 return -EINVAL;
3671
3672 if (xfer->tx_buf && !xfer->tx_nbits)
3673 xfer->tx_nbits = SPI_NBITS_SINGLE;
3674 if (xfer->rx_buf && !xfer->rx_nbits)
3675 xfer->rx_nbits = SPI_NBITS_SINGLE;
3676 /* check transfer tx/rx_nbits:
3677 * 1. check the value matches one of single, dual and quad
3678 * 2. check tx/rx_nbits match the mode in spi_device
3679 */
3680 if (xfer->tx_buf) {
3681 if (spi->mode & SPI_NO_TX)
3682 return -EINVAL;
3683 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3684 xfer->tx_nbits != SPI_NBITS_DUAL &&
3685 xfer->tx_nbits != SPI_NBITS_QUAD)
3686 return -EINVAL;
3687 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3688 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3689 return -EINVAL;
3690 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3691 !(spi->mode & SPI_TX_QUAD))
3692 return -EINVAL;
3693 }
3694 /* check transfer rx_nbits */
3695 if (xfer->rx_buf) {
3696 if (spi->mode & SPI_NO_RX)
3697 return -EINVAL;
3698 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3699 xfer->rx_nbits != SPI_NBITS_DUAL &&
3700 xfer->rx_nbits != SPI_NBITS_QUAD)
3701 return -EINVAL;
3702 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3703 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3704 return -EINVAL;
3705 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3706 !(spi->mode & SPI_RX_QUAD))
3707 return -EINVAL;
3708 }
3709
3710 if (_spi_xfer_word_delay_update(xfer, spi))
3711 return -EINVAL;
3712 }
3713
3714 message->status = -EINPROGRESS;
3715
3716 return 0;
3717}
3718
3719static int __spi_async(struct spi_device *spi, struct spi_message *message)
3720{
3721 struct spi_controller *ctlr = spi->controller;
3722 struct spi_transfer *xfer;
3723
3724 /*
3725 * Some controllers do not support doing regular SPI transfers. Return
3726 * ENOTSUPP when this is the case.
3727 */
3728 if (!ctlr->transfer)
3729 return -ENOTSUPP;
3730
3731 message->spi = spi;
3732
3733 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
3734 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3735
3736 trace_spi_message_submit(message);
3737
3738 if (!ctlr->ptp_sts_supported) {
3739 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3740 xfer->ptp_sts_word_pre = 0;
3741 ptp_read_system_prets(xfer->ptp_sts);
3742 }
3743 }
3744
3745 return ctlr->transfer(spi, message);
3746}
3747
3748/**
3749 * spi_async - asynchronous SPI transfer
3750 * @spi: device with which data will be exchanged
3751 * @message: describes the data transfers, including completion callback
3752 * Context: any (irqs may be blocked, etc)
3753 *
3754 * This call may be used in_irq and other contexts which can't sleep,
3755 * as well as from task contexts which can sleep.
3756 *
3757 * The completion callback is invoked in a context which can't sleep.
3758 * Before that invocation, the value of message->status is undefined.
3759 * When the callback is issued, message->status holds either zero (to
3760 * indicate complete success) or a negative error code. After that
3761 * callback returns, the driver which issued the transfer request may
3762 * deallocate the associated memory; it's no longer in use by any SPI
3763 * core or controller driver code.
3764 *
3765 * Note that although all messages to a spi_device are handled in
3766 * FIFO order, messages may go to different devices in other orders.
3767 * Some device might be higher priority, or have various "hard" access
3768 * time requirements, for example.
3769 *
3770 * On detection of any fault during the transfer, processing of
3771 * the entire message is aborted, and the device is deselected.
3772 * Until returning from the associated message completion callback,
3773 * no other spi_message queued to that device will be processed.
3774 * (This rule applies equally to all the synchronous transfer calls,
3775 * which are wrappers around this core asynchronous primitive.)
3776 *
3777 * Return: zero on success, else a negative error code.
3778 */
3779int spi_async(struct spi_device *spi, struct spi_message *message)
3780{
3781 struct spi_controller *ctlr = spi->controller;
3782 int ret;
3783 unsigned long flags;
3784
3785 ret = __spi_validate(spi, message);
3786 if (ret != 0)
3787 return ret;
3788
3789 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3790
3791 if (ctlr->bus_lock_flag)
3792 ret = -EBUSY;
3793 else
3794 ret = __spi_async(spi, message);
3795
3796 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3797
3798 return ret;
3799}
3800EXPORT_SYMBOL_GPL(spi_async);
3801
3802/**
3803 * spi_async_locked - version of spi_async with exclusive bus usage
3804 * @spi: device with which data will be exchanged
3805 * @message: describes the data transfers, including completion callback
3806 * Context: any (irqs may be blocked, etc)
3807 *
3808 * This call may be used in_irq and other contexts which can't sleep,
3809 * as well as from task contexts which can sleep.
3810 *
3811 * The completion callback is invoked in a context which can't sleep.
3812 * Before that invocation, the value of message->status is undefined.
3813 * When the callback is issued, message->status holds either zero (to
3814 * indicate complete success) or a negative error code. After that
3815 * callback returns, the driver which issued the transfer request may
3816 * deallocate the associated memory; it's no longer in use by any SPI
3817 * core or controller driver code.
3818 *
3819 * Note that although all messages to a spi_device are handled in
3820 * FIFO order, messages may go to different devices in other orders.
3821 * Some device might be higher priority, or have various "hard" access
3822 * time requirements, for example.
3823 *
3824 * On detection of any fault during the transfer, processing of
3825 * the entire message is aborted, and the device is deselected.
3826 * Until returning from the associated message completion callback,
3827 * no other spi_message queued to that device will be processed.
3828 * (This rule applies equally to all the synchronous transfer calls,
3829 * which are wrappers around this core asynchronous primitive.)
3830 *
3831 * Return: zero on success, else a negative error code.
3832 */
3833int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3834{
3835 struct spi_controller *ctlr = spi->controller;
3836 int ret;
3837 unsigned long flags;
3838
3839 ret = __spi_validate(spi, message);
3840 if (ret != 0)
3841 return ret;
3842
3843 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3844
3845 ret = __spi_async(spi, message);
3846
3847 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3848
3849 return ret;
3850
3851}
3852EXPORT_SYMBOL_GPL(spi_async_locked);
3853
3854/*-------------------------------------------------------------------------*/
3855
3856/* Utility methods for SPI protocol drivers, layered on
3857 * top of the core. Some other utility methods are defined as
3858 * inline functions.
3859 */
3860
3861static void spi_complete(void *arg)
3862{
3863 complete(arg);
3864}
3865
3866static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3867{
3868 DECLARE_COMPLETION_ONSTACK(done);
3869 int status;
3870 struct spi_controller *ctlr = spi->controller;
3871 unsigned long flags;
3872
3873 status = __spi_validate(spi, message);
3874 if (status != 0)
3875 return status;
3876
3877 message->complete = spi_complete;
3878 message->context = &done;
3879 message->spi = spi;
3880
3881 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3882 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3883
3884 /* If we're not using the legacy transfer method then we will
3885 * try to transfer in the calling context so special case.
3886 * This code would be less tricky if we could remove the
3887 * support for driver implemented message queues.
3888 */
3889 if (ctlr->transfer == spi_queued_transfer) {
3890 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3891
3892 trace_spi_message_submit(message);
3893
3894 status = __spi_queued_transfer(spi, message, false);
3895
3896 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3897 } else {
3898 status = spi_async_locked(spi, message);
3899 }
3900
3901 if (status == 0) {
3902 /* Push out the messages in the calling context if we
3903 * can.
3904 */
3905 if (ctlr->transfer == spi_queued_transfer) {
3906 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3907 spi_sync_immediate);
3908 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3909 spi_sync_immediate);
3910 __spi_pump_messages(ctlr, false);
3911 }
3912
3913 wait_for_completion(&done);
3914 status = message->status;
3915 }
3916 message->context = NULL;
3917 return status;
3918}
3919
3920/**
3921 * spi_sync - blocking/synchronous SPI data transfers
3922 * @spi: device with which data will be exchanged
3923 * @message: describes the data transfers
3924 * Context: can sleep
3925 *
3926 * This call may only be used from a context that may sleep. The sleep
3927 * is non-interruptible, and has no timeout. Low-overhead controller
3928 * drivers may DMA directly into and out of the message buffers.
3929 *
3930 * Note that the SPI device's chip select is active during the message,
3931 * and then is normally disabled between messages. Drivers for some
3932 * frequently-used devices may want to minimize costs of selecting a chip,
3933 * by leaving it selected in anticipation that the next message will go
3934 * to the same chip. (That may increase power usage.)
3935 *
3936 * Also, the caller is guaranteeing that the memory associated with the
3937 * message will not be freed before this call returns.
3938 *
3939 * Return: zero on success, else a negative error code.
3940 */
3941int spi_sync(struct spi_device *spi, struct spi_message *message)
3942{
3943 int ret;
3944
3945 mutex_lock(&spi->controller->bus_lock_mutex);
3946 ret = __spi_sync(spi, message);
3947 mutex_unlock(&spi->controller->bus_lock_mutex);
3948
3949 return ret;
3950}
3951EXPORT_SYMBOL_GPL(spi_sync);
3952
3953/**
3954 * spi_sync_locked - version of spi_sync with exclusive bus usage
3955 * @spi: device with which data will be exchanged
3956 * @message: describes the data transfers
3957 * Context: can sleep
3958 *
3959 * This call may only be used from a context that may sleep. The sleep
3960 * is non-interruptible, and has no timeout. Low-overhead controller
3961 * drivers may DMA directly into and out of the message buffers.
3962 *
3963 * This call should be used by drivers that require exclusive access to the
3964 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3965 * be released by a spi_bus_unlock call when the exclusive access is over.
3966 *
3967 * Return: zero on success, else a negative error code.
3968 */
3969int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3970{
3971 return __spi_sync(spi, message);
3972}
3973EXPORT_SYMBOL_GPL(spi_sync_locked);
3974
3975/**
3976 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3977 * @ctlr: SPI bus master that should be locked for exclusive bus access
3978 * Context: can sleep
3979 *
3980 * This call may only be used from a context that may sleep. The sleep
3981 * is non-interruptible, and has no timeout.
3982 *
3983 * This call should be used by drivers that require exclusive access to the
3984 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3985 * exclusive access is over. Data transfer must be done by spi_sync_locked
3986 * and spi_async_locked calls when the SPI bus lock is held.
3987 *
3988 * Return: always zero.
3989 */
3990int spi_bus_lock(struct spi_controller *ctlr)
3991{
3992 unsigned long flags;
3993
3994 mutex_lock(&ctlr->bus_lock_mutex);
3995
3996 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3997 ctlr->bus_lock_flag = 1;
3998 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3999
4000 /* mutex remains locked until spi_bus_unlock is called */
4001
4002 return 0;
4003}
4004EXPORT_SYMBOL_GPL(spi_bus_lock);
4005
4006/**
4007 * spi_bus_unlock - release the lock for exclusive SPI bus usage
4008 * @ctlr: SPI bus master that was locked for exclusive bus access
4009 * Context: can sleep
4010 *
4011 * This call may only be used from a context that may sleep. The sleep
4012 * is non-interruptible, and has no timeout.
4013 *
4014 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
4015 * call.
4016 *
4017 * Return: always zero.
4018 */
4019int spi_bus_unlock(struct spi_controller *ctlr)
4020{
4021 ctlr->bus_lock_flag = 0;
4022
4023 mutex_unlock(&ctlr->bus_lock_mutex);
4024
4025 return 0;
4026}
4027EXPORT_SYMBOL_GPL(spi_bus_unlock);
4028
4029/* portable code must never pass more than 32 bytes */
4030#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
4031
4032static u8 *buf;
4033
4034/**
4035 * spi_write_then_read - SPI synchronous write followed by read
4036 * @spi: device with which data will be exchanged
4037 * @txbuf: data to be written (need not be dma-safe)
4038 * @n_tx: size of txbuf, in bytes
4039 * @rxbuf: buffer into which data will be read (need not be dma-safe)
4040 * @n_rx: size of rxbuf, in bytes
4041 * Context: can sleep
4042 *
4043 * This performs a half duplex MicroWire style transaction with the
4044 * device, sending txbuf and then reading rxbuf. The return value
4045 * is zero for success, else a negative errno status code.
4046 * This call may only be used from a context that may sleep.
4047 *
4048 * Parameters to this routine are always copied using a small buffer.
4049 * Performance-sensitive or bulk transfer code should instead use
4050 * spi_{async,sync}() calls with dma-safe buffers.
4051 *
4052 * Return: zero on success, else a negative error code.
4053 */
4054int spi_write_then_read(struct spi_device *spi,
4055 const void *txbuf, unsigned n_tx,
4056 void *rxbuf, unsigned n_rx)
4057{
4058 static DEFINE_MUTEX(lock);
4059
4060 int status;
4061 struct spi_message message;
4062 struct spi_transfer x[2];
4063 u8 *local_buf;
4064
4065 /* Use preallocated DMA-safe buffer if we can. We can't avoid
4066 * copying here, (as a pure convenience thing), but we can
4067 * keep heap costs out of the hot path unless someone else is
4068 * using the pre-allocated buffer or the transfer is too large.
4069 */
4070 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
4071 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
4072 GFP_KERNEL | GFP_DMA);
4073 if (!local_buf)
4074 return -ENOMEM;
4075 } else {
4076 local_buf = buf;
4077 }
4078
4079 spi_message_init(&message);
4080 memset(x, 0, sizeof(x));
4081 if (n_tx) {
4082 x[0].len = n_tx;
4083 spi_message_add_tail(&x[0], &message);
4084 }
4085 if (n_rx) {
4086 x[1].len = n_rx;
4087 spi_message_add_tail(&x[1], &message);
4088 }
4089
4090 memcpy(local_buf, txbuf, n_tx);
4091 x[0].tx_buf = local_buf;
4092 x[1].rx_buf = local_buf + n_tx;
4093
4094 /* do the i/o */
4095 status = spi_sync(spi, &message);
4096 if (status == 0)
4097 memcpy(rxbuf, x[1].rx_buf, n_rx);
4098
4099 if (x[0].tx_buf == buf)
4100 mutex_unlock(&lock);
4101 else
4102 kfree(local_buf);
4103
4104 return status;
4105}
4106EXPORT_SYMBOL_GPL(spi_write_then_read);
4107
4108/*-------------------------------------------------------------------------*/
4109
4110#if IS_ENABLED(CONFIG_OF)
4111/* must call put_device() when done with returned spi_device device */
4112struct spi_device *of_find_spi_device_by_node(struct device_node *node)
4113{
4114 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
4115
4116 return dev ? to_spi_device(dev) : NULL;
4117}
4118EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
4119#endif /* IS_ENABLED(CONFIG_OF) */
4120
4121#if IS_ENABLED(CONFIG_OF_DYNAMIC)
4122/* the spi controllers are not using spi_bus, so we find it with another way */
4123static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
4124{
4125 struct device *dev;
4126
4127 dev = class_find_device_by_of_node(&spi_master_class, node);
4128 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4129 dev = class_find_device_by_of_node(&spi_slave_class, node);
4130 if (!dev)
4131 return NULL;
4132
4133 /* reference got in class_find_device */
4134 return container_of(dev, struct spi_controller, dev);
4135}
4136
4137static int of_spi_notify(struct notifier_block *nb, unsigned long action,
4138 void *arg)
4139{
4140 struct of_reconfig_data *rd = arg;
4141 struct spi_controller *ctlr;
4142 struct spi_device *spi;
4143
4144 switch (of_reconfig_get_state_change(action, arg)) {
4145 case OF_RECONFIG_CHANGE_ADD:
4146 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
4147 if (ctlr == NULL)
4148 return NOTIFY_OK; /* not for us */
4149
4150 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
4151 put_device(&ctlr->dev);
4152 return NOTIFY_OK;
4153 }
4154
4155 spi = of_register_spi_device(ctlr, rd->dn);
4156 put_device(&ctlr->dev);
4157
4158 if (IS_ERR(spi)) {
4159 pr_err("%s: failed to create for '%pOF'\n",
4160 __func__, rd->dn);
4161 of_node_clear_flag(rd->dn, OF_POPULATED);
4162 return notifier_from_errno(PTR_ERR(spi));
4163 }
4164 break;
4165
4166 case OF_RECONFIG_CHANGE_REMOVE:
4167 /* already depopulated? */
4168 if (!of_node_check_flag(rd->dn, OF_POPULATED))
4169 return NOTIFY_OK;
4170
4171 /* find our device by node */
4172 spi = of_find_spi_device_by_node(rd->dn);
4173 if (spi == NULL)
4174 return NOTIFY_OK; /* no? not meant for us */
4175
4176 /* unregister takes one ref away */
4177 spi_unregister_device(spi);
4178
4179 /* and put the reference of the find */
4180 put_device(&spi->dev);
4181 break;
4182 }
4183
4184 return NOTIFY_OK;
4185}
4186
4187static struct notifier_block spi_of_notifier = {
4188 .notifier_call = of_spi_notify,
4189};
4190#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4191extern struct notifier_block spi_of_notifier;
4192#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4193
4194#if IS_ENABLED(CONFIG_ACPI)
4195static int spi_acpi_controller_match(struct device *dev, const void *data)
4196{
4197 return ACPI_COMPANION(dev->parent) == data;
4198}
4199
4200static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4201{
4202 struct device *dev;
4203
4204 dev = class_find_device(&spi_master_class, NULL, adev,
4205 spi_acpi_controller_match);
4206 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4207 dev = class_find_device(&spi_slave_class, NULL, adev,
4208 spi_acpi_controller_match);
4209 if (!dev)
4210 return NULL;
4211
4212 return container_of(dev, struct spi_controller, dev);
4213}
4214
4215static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4216{
4217 struct device *dev;
4218
4219 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4220 return to_spi_device(dev);
4221}
4222
4223static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4224 void *arg)
4225{
4226 struct acpi_device *adev = arg;
4227 struct spi_controller *ctlr;
4228 struct spi_device *spi;
4229
4230 switch (value) {
4231 case ACPI_RECONFIG_DEVICE_ADD:
4232 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
4233 if (!ctlr)
4234 break;
4235
4236 acpi_register_spi_device(ctlr, adev);
4237 put_device(&ctlr->dev);
4238 break;
4239 case ACPI_RECONFIG_DEVICE_REMOVE:
4240 if (!acpi_device_enumerated(adev))
4241 break;
4242
4243 spi = acpi_spi_find_device_by_adev(adev);
4244 if (!spi)
4245 break;
4246
4247 spi_unregister_device(spi);
4248 put_device(&spi->dev);
4249 break;
4250 }
4251
4252 return NOTIFY_OK;
4253}
4254
4255static struct notifier_block spi_acpi_notifier = {
4256 .notifier_call = acpi_spi_notify,
4257};
4258#else
4259extern struct notifier_block spi_acpi_notifier;
4260#endif
4261
4262static int __init spi_init(void)
4263{
4264 int status;
4265
4266 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4267 if (!buf) {
4268 status = -ENOMEM;
4269 goto err0;
4270 }
4271
4272 status = bus_register(&spi_bus_type);
4273 if (status < 0)
4274 goto err1;
4275
4276 status = class_register(&spi_master_class);
4277 if (status < 0)
4278 goto err2;
4279
4280 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4281 status = class_register(&spi_slave_class);
4282 if (status < 0)
4283 goto err3;
4284 }
4285
4286 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4287 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4288 if (IS_ENABLED(CONFIG_ACPI))
4289 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4290
4291 return 0;
4292
4293err3:
4294 class_unregister(&spi_master_class);
4295err2:
4296 bus_unregister(&spi_bus_type);
4297err1:
4298 kfree(buf);
4299 buf = NULL;
4300err0:
4301 return status;
4302}
4303
4304/* board_info is normally registered in arch_initcall(),
4305 * but even essential drivers wait till later
4306 *
4307 * REVISIT only boardinfo really needs static linking. the rest (device and
4308 * driver registration) _could_ be dynamically linked (modular) ... costs
4309 * include needing to have boardinfo data structures be much more public.
4310 */
4311postcore_initcall(spi_init);