Merge branches 'topic/core', 'topic/slave' and 'fix/doc' of git://git.kernel.org...
[muen/linux.git] / drivers / spi / spi.c
1 /*
2  * SPI init/core code
3  *
4  * Copyright (C) 2005 David Brownell
5  * Copyright (C) 2008 Secret Lab Technologies Ltd.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  */
17
18 #include <linux/kernel.h>
19 #include <linux/device.h>
20 #include <linux/init.h>
21 #include <linux/cache.h>
22 #include <linux/dma-mapping.h>
23 #include <linux/dmaengine.h>
24 #include <linux/mutex.h>
25 #include <linux/of_device.h>
26 #include <linux/of_irq.h>
27 #include <linux/clk/clk-conf.h>
28 #include <linux/slab.h>
29 #include <linux/mod_devicetable.h>
30 #include <linux/spi/spi.h>
31 #include <linux/of_gpio.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/pm_domain.h>
34 #include <linux/property.h>
35 #include <linux/export.h>
36 #include <linux/sched/rt.h>
37 #include <uapi/linux/sched/types.h>
38 #include <linux/delay.h>
39 #include <linux/kthread.h>
40 #include <linux/ioport.h>
41 #include <linux/acpi.h>
42 #include <linux/highmem.h>
43
44 #define CREATE_TRACE_POINTS
45 #include <trace/events/spi.h>
46
47 static void spidev_release(struct device *dev)
48 {
49         struct spi_device       *spi = to_spi_device(dev);
50
51         /* spi masters may cleanup for released devices */
52         if (spi->master->cleanup)
53                 spi->master->cleanup(spi);
54
55         spi_master_put(spi->master);
56         kfree(spi);
57 }
58
59 static ssize_t
60 modalias_show(struct device *dev, struct device_attribute *a, char *buf)
61 {
62         const struct spi_device *spi = to_spi_device(dev);
63         int len;
64
65         len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
66         if (len != -ENODEV)
67                 return len;
68
69         return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
70 }
71 static DEVICE_ATTR_RO(modalias);
72
73 #define SPI_STATISTICS_ATTRS(field, file)                               \
74 static ssize_t spi_master_##field##_show(struct device *dev,            \
75                                          struct device_attribute *attr, \
76                                          char *buf)                     \
77 {                                                                       \
78         struct spi_master *master = container_of(dev,                   \
79                                                  struct spi_master, dev); \
80         return spi_statistics_##field##_show(&master->statistics, buf); \
81 }                                                                       \
82 static struct device_attribute dev_attr_spi_master_##field = {          \
83         .attr = { .name = file, .mode = 0444 },                         \
84         .show = spi_master_##field##_show,                              \
85 };                                                                      \
86 static ssize_t spi_device_##field##_show(struct device *dev,            \
87                                          struct device_attribute *attr, \
88                                         char *buf)                      \
89 {                                                                       \
90         struct spi_device *spi = to_spi_device(dev);                    \
91         return spi_statistics_##field##_show(&spi->statistics, buf);    \
92 }                                                                       \
93 static struct device_attribute dev_attr_spi_device_##field = {          \
94         .attr = { .name = file, .mode = 0444 },                         \
95         .show = spi_device_##field##_show,                              \
96 }
97
98 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string)      \
99 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
100                                             char *buf)                  \
101 {                                                                       \
102         unsigned long flags;                                            \
103         ssize_t len;                                                    \
104         spin_lock_irqsave(&stat->lock, flags);                          \
105         len = sprintf(buf, format_string, stat->field);                 \
106         spin_unlock_irqrestore(&stat->lock, flags);                     \
107         return len;                                                     \
108 }                                                                       \
109 SPI_STATISTICS_ATTRS(name, file)
110
111 #define SPI_STATISTICS_SHOW(field, format_string)                       \
112         SPI_STATISTICS_SHOW_NAME(field, __stringify(field),             \
113                                  field, format_string)
114
115 SPI_STATISTICS_SHOW(messages, "%lu");
116 SPI_STATISTICS_SHOW(transfers, "%lu");
117 SPI_STATISTICS_SHOW(errors, "%lu");
118 SPI_STATISTICS_SHOW(timedout, "%lu");
119
120 SPI_STATISTICS_SHOW(spi_sync, "%lu");
121 SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
122 SPI_STATISTICS_SHOW(spi_async, "%lu");
123
124 SPI_STATISTICS_SHOW(bytes, "%llu");
125 SPI_STATISTICS_SHOW(bytes_rx, "%llu");
126 SPI_STATISTICS_SHOW(bytes_tx, "%llu");
127
128 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number)              \
129         SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index,           \
130                                  "transfer_bytes_histo_" number,        \
131                                  transfer_bytes_histo[index],  "%lu")
132 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0,  "0-1");
133 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1,  "2-3");
134 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2,  "4-7");
135 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3,  "8-15");
136 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4,  "16-31");
137 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5,  "32-63");
138 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6,  "64-127");
139 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7,  "128-255");
140 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8,  "256-511");
141 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9,  "512-1023");
142 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
143 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
144 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
145 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
146 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
147 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
148 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
149
150 SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
151
152 static struct attribute *spi_dev_attrs[] = {
153         &dev_attr_modalias.attr,
154         NULL,
155 };
156
157 static const struct attribute_group spi_dev_group = {
158         .attrs  = spi_dev_attrs,
159 };
160
161 static struct attribute *spi_device_statistics_attrs[] = {
162         &dev_attr_spi_device_messages.attr,
163         &dev_attr_spi_device_transfers.attr,
164         &dev_attr_spi_device_errors.attr,
165         &dev_attr_spi_device_timedout.attr,
166         &dev_attr_spi_device_spi_sync.attr,
167         &dev_attr_spi_device_spi_sync_immediate.attr,
168         &dev_attr_spi_device_spi_async.attr,
169         &dev_attr_spi_device_bytes.attr,
170         &dev_attr_spi_device_bytes_rx.attr,
171         &dev_attr_spi_device_bytes_tx.attr,
172         &dev_attr_spi_device_transfer_bytes_histo0.attr,
173         &dev_attr_spi_device_transfer_bytes_histo1.attr,
174         &dev_attr_spi_device_transfer_bytes_histo2.attr,
175         &dev_attr_spi_device_transfer_bytes_histo3.attr,
176         &dev_attr_spi_device_transfer_bytes_histo4.attr,
177         &dev_attr_spi_device_transfer_bytes_histo5.attr,
178         &dev_attr_spi_device_transfer_bytes_histo6.attr,
179         &dev_attr_spi_device_transfer_bytes_histo7.attr,
180         &dev_attr_spi_device_transfer_bytes_histo8.attr,
181         &dev_attr_spi_device_transfer_bytes_histo9.attr,
182         &dev_attr_spi_device_transfer_bytes_histo10.attr,
183         &dev_attr_spi_device_transfer_bytes_histo11.attr,
184         &dev_attr_spi_device_transfer_bytes_histo12.attr,
185         &dev_attr_spi_device_transfer_bytes_histo13.attr,
186         &dev_attr_spi_device_transfer_bytes_histo14.attr,
187         &dev_attr_spi_device_transfer_bytes_histo15.attr,
188         &dev_attr_spi_device_transfer_bytes_histo16.attr,
189         &dev_attr_spi_device_transfers_split_maxsize.attr,
190         NULL,
191 };
192
193 static const struct attribute_group spi_device_statistics_group = {
194         .name  = "statistics",
195         .attrs  = spi_device_statistics_attrs,
196 };
197
198 static const struct attribute_group *spi_dev_groups[] = {
199         &spi_dev_group,
200         &spi_device_statistics_group,
201         NULL,
202 };
203
204 static struct attribute *spi_master_statistics_attrs[] = {
205         &dev_attr_spi_master_messages.attr,
206         &dev_attr_spi_master_transfers.attr,
207         &dev_attr_spi_master_errors.attr,
208         &dev_attr_spi_master_timedout.attr,
209         &dev_attr_spi_master_spi_sync.attr,
210         &dev_attr_spi_master_spi_sync_immediate.attr,
211         &dev_attr_spi_master_spi_async.attr,
212         &dev_attr_spi_master_bytes.attr,
213         &dev_attr_spi_master_bytes_rx.attr,
214         &dev_attr_spi_master_bytes_tx.attr,
215         &dev_attr_spi_master_transfer_bytes_histo0.attr,
216         &dev_attr_spi_master_transfer_bytes_histo1.attr,
217         &dev_attr_spi_master_transfer_bytes_histo2.attr,
218         &dev_attr_spi_master_transfer_bytes_histo3.attr,
219         &dev_attr_spi_master_transfer_bytes_histo4.attr,
220         &dev_attr_spi_master_transfer_bytes_histo5.attr,
221         &dev_attr_spi_master_transfer_bytes_histo6.attr,
222         &dev_attr_spi_master_transfer_bytes_histo7.attr,
223         &dev_attr_spi_master_transfer_bytes_histo8.attr,
224         &dev_attr_spi_master_transfer_bytes_histo9.attr,
225         &dev_attr_spi_master_transfer_bytes_histo10.attr,
226         &dev_attr_spi_master_transfer_bytes_histo11.attr,
227         &dev_attr_spi_master_transfer_bytes_histo12.attr,
228         &dev_attr_spi_master_transfer_bytes_histo13.attr,
229         &dev_attr_spi_master_transfer_bytes_histo14.attr,
230         &dev_attr_spi_master_transfer_bytes_histo15.attr,
231         &dev_attr_spi_master_transfer_bytes_histo16.attr,
232         &dev_attr_spi_master_transfers_split_maxsize.attr,
233         NULL,
234 };
235
236 static const struct attribute_group spi_master_statistics_group = {
237         .name  = "statistics",
238         .attrs  = spi_master_statistics_attrs,
239 };
240
241 static const struct attribute_group *spi_master_groups[] = {
242         &spi_master_statistics_group,
243         NULL,
244 };
245
246 void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
247                                        struct spi_transfer *xfer,
248                                        struct spi_master *master)
249 {
250         unsigned long flags;
251         int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
252
253         if (l2len < 0)
254                 l2len = 0;
255
256         spin_lock_irqsave(&stats->lock, flags);
257
258         stats->transfers++;
259         stats->transfer_bytes_histo[l2len]++;
260
261         stats->bytes += xfer->len;
262         if ((xfer->tx_buf) &&
263             (xfer->tx_buf != master->dummy_tx))
264                 stats->bytes_tx += xfer->len;
265         if ((xfer->rx_buf) &&
266             (xfer->rx_buf != master->dummy_rx))
267                 stats->bytes_rx += xfer->len;
268
269         spin_unlock_irqrestore(&stats->lock, flags);
270 }
271 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
272
273 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
274  * and the sysfs version makes coldplug work too.
275  */
276
277 static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
278                                                 const struct spi_device *sdev)
279 {
280         while (id->name[0]) {
281                 if (!strcmp(sdev->modalias, id->name))
282                         return id;
283                 id++;
284         }
285         return NULL;
286 }
287
288 const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
289 {
290         const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
291
292         return spi_match_id(sdrv->id_table, sdev);
293 }
294 EXPORT_SYMBOL_GPL(spi_get_device_id);
295
296 static int spi_match_device(struct device *dev, struct device_driver *drv)
297 {
298         const struct spi_device *spi = to_spi_device(dev);
299         const struct spi_driver *sdrv = to_spi_driver(drv);
300
301         /* Attempt an OF style match */
302         if (of_driver_match_device(dev, drv))
303                 return 1;
304
305         /* Then try ACPI */
306         if (acpi_driver_match_device(dev, drv))
307                 return 1;
308
309         if (sdrv->id_table)
310                 return !!spi_match_id(sdrv->id_table, spi);
311
312         return strcmp(spi->modalias, drv->name) == 0;
313 }
314
315 static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
316 {
317         const struct spi_device         *spi = to_spi_device(dev);
318         int rc;
319
320         rc = acpi_device_uevent_modalias(dev, env);
321         if (rc != -ENODEV)
322                 return rc;
323
324         add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
325         return 0;
326 }
327
328 struct bus_type spi_bus_type = {
329         .name           = "spi",
330         .dev_groups     = spi_dev_groups,
331         .match          = spi_match_device,
332         .uevent         = spi_uevent,
333 };
334 EXPORT_SYMBOL_GPL(spi_bus_type);
335
336
337 static int spi_drv_probe(struct device *dev)
338 {
339         const struct spi_driver         *sdrv = to_spi_driver(dev->driver);
340         struct spi_device               *spi = to_spi_device(dev);
341         int ret;
342
343         ret = of_clk_set_defaults(dev->of_node, false);
344         if (ret)
345                 return ret;
346
347         if (dev->of_node) {
348                 spi->irq = of_irq_get(dev->of_node, 0);
349                 if (spi->irq == -EPROBE_DEFER)
350                         return -EPROBE_DEFER;
351                 if (spi->irq < 0)
352                         spi->irq = 0;
353         }
354
355         ret = dev_pm_domain_attach(dev, true);
356         if (ret != -EPROBE_DEFER) {
357                 ret = sdrv->probe(spi);
358                 if (ret)
359                         dev_pm_domain_detach(dev, true);
360         }
361
362         return ret;
363 }
364
365 static int spi_drv_remove(struct device *dev)
366 {
367         const struct spi_driver         *sdrv = to_spi_driver(dev->driver);
368         int ret;
369
370         ret = sdrv->remove(to_spi_device(dev));
371         dev_pm_domain_detach(dev, true);
372
373         return ret;
374 }
375
376 static void spi_drv_shutdown(struct device *dev)
377 {
378         const struct spi_driver         *sdrv = to_spi_driver(dev->driver);
379
380         sdrv->shutdown(to_spi_device(dev));
381 }
382
383 /**
384  * __spi_register_driver - register a SPI driver
385  * @owner: owner module of the driver to register
386  * @sdrv: the driver to register
387  * Context: can sleep
388  *
389  * Return: zero on success, else a negative error code.
390  */
391 int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
392 {
393         sdrv->driver.owner = owner;
394         sdrv->driver.bus = &spi_bus_type;
395         if (sdrv->probe)
396                 sdrv->driver.probe = spi_drv_probe;
397         if (sdrv->remove)
398                 sdrv->driver.remove = spi_drv_remove;
399         if (sdrv->shutdown)
400                 sdrv->driver.shutdown = spi_drv_shutdown;
401         return driver_register(&sdrv->driver);
402 }
403 EXPORT_SYMBOL_GPL(__spi_register_driver);
404
405 /*-------------------------------------------------------------------------*/
406
407 /* SPI devices should normally not be created by SPI device drivers; that
408  * would make them board-specific.  Similarly with SPI master drivers.
409  * Device registration normally goes into like arch/.../mach.../board-YYY.c
410  * with other readonly (flashable) information about mainboard devices.
411  */
412
413 struct boardinfo {
414         struct list_head        list;
415         struct spi_board_info   board_info;
416 };
417
418 static LIST_HEAD(board_list);
419 static LIST_HEAD(spi_master_list);
420
421 /*
422  * Used to protect add/del opertion for board_info list and
423  * spi_master list, and their matching process
424  */
425 static DEFINE_MUTEX(board_lock);
426
427 /**
428  * spi_alloc_device - Allocate a new SPI device
429  * @master: Controller to which device is connected
430  * Context: can sleep
431  *
432  * Allows a driver to allocate and initialize a spi_device without
433  * registering it immediately.  This allows a driver to directly
434  * fill the spi_device with device parameters before calling
435  * spi_add_device() on it.
436  *
437  * Caller is responsible to call spi_add_device() on the returned
438  * spi_device structure to add it to the SPI master.  If the caller
439  * needs to discard the spi_device without adding it, then it should
440  * call spi_dev_put() on it.
441  *
442  * Return: a pointer to the new device, or NULL.
443  */
444 struct spi_device *spi_alloc_device(struct spi_master *master)
445 {
446         struct spi_device       *spi;
447
448         if (!spi_master_get(master))
449                 return NULL;
450
451         spi = kzalloc(sizeof(*spi), GFP_KERNEL);
452         if (!spi) {
453                 spi_master_put(master);
454                 return NULL;
455         }
456
457         spi->master = master;
458         spi->dev.parent = &master->dev;
459         spi->dev.bus = &spi_bus_type;
460         spi->dev.release = spidev_release;
461         spi->cs_gpio = -ENOENT;
462
463         spin_lock_init(&spi->statistics.lock);
464
465         device_initialize(&spi->dev);
466         return spi;
467 }
468 EXPORT_SYMBOL_GPL(spi_alloc_device);
469
470 static void spi_dev_set_name(struct spi_device *spi)
471 {
472         struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
473
474         if (adev) {
475                 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
476                 return;
477         }
478
479         dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
480                      spi->chip_select);
481 }
482
483 static int spi_dev_check(struct device *dev, void *data)
484 {
485         struct spi_device *spi = to_spi_device(dev);
486         struct spi_device *new_spi = data;
487
488         if (spi->master == new_spi->master &&
489             spi->chip_select == new_spi->chip_select)
490                 return -EBUSY;
491         return 0;
492 }
493
494 /**
495  * spi_add_device - Add spi_device allocated with spi_alloc_device
496  * @spi: spi_device to register
497  *
498  * Companion function to spi_alloc_device.  Devices allocated with
499  * spi_alloc_device can be added onto the spi bus with this function.
500  *
501  * Return: 0 on success; negative errno on failure
502  */
503 int spi_add_device(struct spi_device *spi)
504 {
505         static DEFINE_MUTEX(spi_add_lock);
506         struct spi_master *master = spi->master;
507         struct device *dev = master->dev.parent;
508         int status;
509
510         /* Chipselects are numbered 0..max; validate. */
511         if (spi->chip_select >= master->num_chipselect) {
512                 dev_err(dev, "cs%d >= max %d\n",
513                         spi->chip_select,
514                         master->num_chipselect);
515                 return -EINVAL;
516         }
517
518         /* Set the bus ID string */
519         spi_dev_set_name(spi);
520
521         /* We need to make sure there's no other device with this
522          * chipselect **BEFORE** we call setup(), else we'll trash
523          * its configuration.  Lock against concurrent add() calls.
524          */
525         mutex_lock(&spi_add_lock);
526
527         status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
528         if (status) {
529                 dev_err(dev, "chipselect %d already in use\n",
530                                 spi->chip_select);
531                 goto done;
532         }
533
534         if (master->cs_gpios)
535                 spi->cs_gpio = master->cs_gpios[spi->chip_select];
536
537         /* Drivers may modify this initial i/o setup, but will
538          * normally rely on the device being setup.  Devices
539          * using SPI_CS_HIGH can't coexist well otherwise...
540          */
541         status = spi_setup(spi);
542         if (status < 0) {
543                 dev_err(dev, "can't setup %s, status %d\n",
544                                 dev_name(&spi->dev), status);
545                 goto done;
546         }
547
548         /* Device may be bound to an active driver when this returns */
549         status = device_add(&spi->dev);
550         if (status < 0)
551                 dev_err(dev, "can't add %s, status %d\n",
552                                 dev_name(&spi->dev), status);
553         else
554                 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
555
556 done:
557         mutex_unlock(&spi_add_lock);
558         return status;
559 }
560 EXPORT_SYMBOL_GPL(spi_add_device);
561
562 /**
563  * spi_new_device - instantiate one new SPI device
564  * @master: Controller to which device is connected
565  * @chip: Describes the SPI device
566  * Context: can sleep
567  *
568  * On typical mainboards, this is purely internal; and it's not needed
569  * after board init creates the hard-wired devices.  Some development
570  * platforms may not be able to use spi_register_board_info though, and
571  * this is exported so that for example a USB or parport based adapter
572  * driver could add devices (which it would learn about out-of-band).
573  *
574  * Return: the new device, or NULL.
575  */
576 struct spi_device *spi_new_device(struct spi_master *master,
577                                   struct spi_board_info *chip)
578 {
579         struct spi_device       *proxy;
580         int                     status;
581
582         /* NOTE:  caller did any chip->bus_num checks necessary.
583          *
584          * Also, unless we change the return value convention to use
585          * error-or-pointer (not NULL-or-pointer), troubleshootability
586          * suggests syslogged diagnostics are best here (ugh).
587          */
588
589         proxy = spi_alloc_device(master);
590         if (!proxy)
591                 return NULL;
592
593         WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
594
595         proxy->chip_select = chip->chip_select;
596         proxy->max_speed_hz = chip->max_speed_hz;
597         proxy->mode = chip->mode;
598         proxy->irq = chip->irq;
599         strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
600         proxy->dev.platform_data = (void *) chip->platform_data;
601         proxy->controller_data = chip->controller_data;
602         proxy->controller_state = NULL;
603
604         if (chip->properties) {
605                 status = device_add_properties(&proxy->dev, chip->properties);
606                 if (status) {
607                         dev_err(&master->dev,
608                                 "failed to add properties to '%s': %d\n",
609                                 chip->modalias, status);
610                         goto err_dev_put;
611                 }
612         }
613
614         status = spi_add_device(proxy);
615         if (status < 0)
616                 goto err_remove_props;
617
618         return proxy;
619
620 err_remove_props:
621         if (chip->properties)
622                 device_remove_properties(&proxy->dev);
623 err_dev_put:
624         spi_dev_put(proxy);
625         return NULL;
626 }
627 EXPORT_SYMBOL_GPL(spi_new_device);
628
629 /**
630  * spi_unregister_device - unregister a single SPI device
631  * @spi: spi_device to unregister
632  *
633  * Start making the passed SPI device vanish. Normally this would be handled
634  * by spi_unregister_master().
635  */
636 void spi_unregister_device(struct spi_device *spi)
637 {
638         if (!spi)
639                 return;
640
641         if (spi->dev.of_node) {
642                 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
643                 of_node_put(spi->dev.of_node);
644         }
645         if (ACPI_COMPANION(&spi->dev))
646                 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
647         device_unregister(&spi->dev);
648 }
649 EXPORT_SYMBOL_GPL(spi_unregister_device);
650
651 static void spi_match_master_to_boardinfo(struct spi_master *master,
652                                 struct spi_board_info *bi)
653 {
654         struct spi_device *dev;
655
656         if (master->bus_num != bi->bus_num)
657                 return;
658
659         dev = spi_new_device(master, bi);
660         if (!dev)
661                 dev_err(master->dev.parent, "can't create new device for %s\n",
662                         bi->modalias);
663 }
664
665 /**
666  * spi_register_board_info - register SPI devices for a given board
667  * @info: array of chip descriptors
668  * @n: how many descriptors are provided
669  * Context: can sleep
670  *
671  * Board-specific early init code calls this (probably during arch_initcall)
672  * with segments of the SPI device table.  Any device nodes are created later,
673  * after the relevant parent SPI controller (bus_num) is defined.  We keep
674  * this table of devices forever, so that reloading a controller driver will
675  * not make Linux forget about these hard-wired devices.
676  *
677  * Other code can also call this, e.g. a particular add-on board might provide
678  * SPI devices through its expansion connector, so code initializing that board
679  * would naturally declare its SPI devices.
680  *
681  * The board info passed can safely be __initdata ... but be careful of
682  * any embedded pointers (platform_data, etc), they're copied as-is.
683  * Device properties are deep-copied though.
684  *
685  * Return: zero on success, else a negative error code.
686  */
687 int spi_register_board_info(struct spi_board_info const *info, unsigned n)
688 {
689         struct boardinfo *bi;
690         int i;
691
692         if (!n)
693                 return 0;
694
695         bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
696         if (!bi)
697                 return -ENOMEM;
698
699         for (i = 0; i < n; i++, bi++, info++) {
700                 struct spi_master *master;
701
702                 memcpy(&bi->board_info, info, sizeof(*info));
703                 if (info->properties) {
704                         bi->board_info.properties =
705                                         property_entries_dup(info->properties);
706                         if (IS_ERR(bi->board_info.properties))
707                                 return PTR_ERR(bi->board_info.properties);
708                 }
709
710                 mutex_lock(&board_lock);
711                 list_add_tail(&bi->list, &board_list);
712                 list_for_each_entry(master, &spi_master_list, list)
713                         spi_match_master_to_boardinfo(master, &bi->board_info);
714                 mutex_unlock(&board_lock);
715         }
716
717         return 0;
718 }
719
720 /*-------------------------------------------------------------------------*/
721
722 static void spi_set_cs(struct spi_device *spi, bool enable)
723 {
724         if (spi->mode & SPI_CS_HIGH)
725                 enable = !enable;
726
727         if (gpio_is_valid(spi->cs_gpio)) {
728                 gpio_set_value(spi->cs_gpio, !enable);
729                 /* Some SPI masters need both GPIO CS & slave_select */
730                 if ((spi->master->flags & SPI_MASTER_GPIO_SS) &&
731                     spi->master->set_cs)
732                         spi->master->set_cs(spi, !enable);
733         } else if (spi->master->set_cs) {
734                 spi->master->set_cs(spi, !enable);
735         }
736 }
737
738 #ifdef CONFIG_HAS_DMA
739 static int spi_map_buf(struct spi_master *master, struct device *dev,
740                        struct sg_table *sgt, void *buf, size_t len,
741                        enum dma_data_direction dir)
742 {
743         const bool vmalloced_buf = is_vmalloc_addr(buf);
744         unsigned int max_seg_size = dma_get_max_seg_size(dev);
745 #ifdef CONFIG_HIGHMEM
746         const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
747                                 (unsigned long)buf < (PKMAP_BASE +
748                                         (LAST_PKMAP * PAGE_SIZE)));
749 #else
750         const bool kmap_buf = false;
751 #endif
752         int desc_len;
753         int sgs;
754         struct page *vm_page;
755         struct scatterlist *sg;
756         void *sg_buf;
757         size_t min;
758         int i, ret;
759
760         if (vmalloced_buf || kmap_buf) {
761                 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
762                 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
763         } else if (virt_addr_valid(buf)) {
764                 desc_len = min_t(int, max_seg_size, master->max_dma_len);
765                 sgs = DIV_ROUND_UP(len, desc_len);
766         } else {
767                 return -EINVAL;
768         }
769
770         ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
771         if (ret != 0)
772                 return ret;
773
774         sg = &sgt->sgl[0];
775         for (i = 0; i < sgs; i++) {
776
777                 if (vmalloced_buf || kmap_buf) {
778                         min = min_t(size_t,
779                                     len, desc_len - offset_in_page(buf));
780                         if (vmalloced_buf)
781                                 vm_page = vmalloc_to_page(buf);
782                         else
783                                 vm_page = kmap_to_page(buf);
784                         if (!vm_page) {
785                                 sg_free_table(sgt);
786                                 return -ENOMEM;
787                         }
788                         sg_set_page(sg, vm_page,
789                                     min, offset_in_page(buf));
790                 } else {
791                         min = min_t(size_t, len, desc_len);
792                         sg_buf = buf;
793                         sg_set_buf(sg, sg_buf, min);
794                 }
795
796                 buf += min;
797                 len -= min;
798                 sg = sg_next(sg);
799         }
800
801         ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
802         if (!ret)
803                 ret = -ENOMEM;
804         if (ret < 0) {
805                 sg_free_table(sgt);
806                 return ret;
807         }
808
809         sgt->nents = ret;
810
811         return 0;
812 }
813
814 static void spi_unmap_buf(struct spi_master *master, struct device *dev,
815                           struct sg_table *sgt, enum dma_data_direction dir)
816 {
817         if (sgt->orig_nents) {
818                 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
819                 sg_free_table(sgt);
820         }
821 }
822
823 static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
824 {
825         struct device *tx_dev, *rx_dev;
826         struct spi_transfer *xfer;
827         int ret;
828
829         if (!master->can_dma)
830                 return 0;
831
832         if (master->dma_tx)
833                 tx_dev = master->dma_tx->device->dev;
834         else
835                 tx_dev = master->dev.parent;
836
837         if (master->dma_rx)
838                 rx_dev = master->dma_rx->device->dev;
839         else
840                 rx_dev = master->dev.parent;
841
842         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
843                 if (!master->can_dma(master, msg->spi, xfer))
844                         continue;
845
846                 if (xfer->tx_buf != NULL) {
847                         ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
848                                           (void *)xfer->tx_buf, xfer->len,
849                                           DMA_TO_DEVICE);
850                         if (ret != 0)
851                                 return ret;
852                 }
853
854                 if (xfer->rx_buf != NULL) {
855                         ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
856                                           xfer->rx_buf, xfer->len,
857                                           DMA_FROM_DEVICE);
858                         if (ret != 0) {
859                                 spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
860                                               DMA_TO_DEVICE);
861                                 return ret;
862                         }
863                 }
864         }
865
866         master->cur_msg_mapped = true;
867
868         return 0;
869 }
870
871 static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
872 {
873         struct spi_transfer *xfer;
874         struct device *tx_dev, *rx_dev;
875
876         if (!master->cur_msg_mapped || !master->can_dma)
877                 return 0;
878
879         if (master->dma_tx)
880                 tx_dev = master->dma_tx->device->dev;
881         else
882                 tx_dev = master->dev.parent;
883
884         if (master->dma_rx)
885                 rx_dev = master->dma_rx->device->dev;
886         else
887                 rx_dev = master->dev.parent;
888
889         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
890                 if (!master->can_dma(master, msg->spi, xfer))
891                         continue;
892
893                 spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
894                 spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
895         }
896
897         return 0;
898 }
899 #else /* !CONFIG_HAS_DMA */
900 static inline int spi_map_buf(struct spi_master *master,
901                               struct device *dev, struct sg_table *sgt,
902                               void *buf, size_t len,
903                               enum dma_data_direction dir)
904 {
905         return -EINVAL;
906 }
907
908 static inline void spi_unmap_buf(struct spi_master *master,
909                                  struct device *dev, struct sg_table *sgt,
910                                  enum dma_data_direction dir)
911 {
912 }
913
914 static inline int __spi_map_msg(struct spi_master *master,
915                                 struct spi_message *msg)
916 {
917         return 0;
918 }
919
920 static inline int __spi_unmap_msg(struct spi_master *master,
921                                   struct spi_message *msg)
922 {
923         return 0;
924 }
925 #endif /* !CONFIG_HAS_DMA */
926
927 static inline int spi_unmap_msg(struct spi_master *master,
928                                 struct spi_message *msg)
929 {
930         struct spi_transfer *xfer;
931
932         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
933                 /*
934                  * Restore the original value of tx_buf or rx_buf if they are
935                  * NULL.
936                  */
937                 if (xfer->tx_buf == master->dummy_tx)
938                         xfer->tx_buf = NULL;
939                 if (xfer->rx_buf == master->dummy_rx)
940                         xfer->rx_buf = NULL;
941         }
942
943         return __spi_unmap_msg(master, msg);
944 }
945
946 static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
947 {
948         struct spi_transfer *xfer;
949         void *tmp;
950         unsigned int max_tx, max_rx;
951
952         if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
953                 max_tx = 0;
954                 max_rx = 0;
955
956                 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
957                         if ((master->flags & SPI_MASTER_MUST_TX) &&
958                             !xfer->tx_buf)
959                                 max_tx = max(xfer->len, max_tx);
960                         if ((master->flags & SPI_MASTER_MUST_RX) &&
961                             !xfer->rx_buf)
962                                 max_rx = max(xfer->len, max_rx);
963                 }
964
965                 if (max_tx) {
966                         tmp = krealloc(master->dummy_tx, max_tx,
967                                        GFP_KERNEL | GFP_DMA);
968                         if (!tmp)
969                                 return -ENOMEM;
970                         master->dummy_tx = tmp;
971                         memset(tmp, 0, max_tx);
972                 }
973
974                 if (max_rx) {
975                         tmp = krealloc(master->dummy_rx, max_rx,
976                                        GFP_KERNEL | GFP_DMA);
977                         if (!tmp)
978                                 return -ENOMEM;
979                         master->dummy_rx = tmp;
980                 }
981
982                 if (max_tx || max_rx) {
983                         list_for_each_entry(xfer, &msg->transfers,
984                                             transfer_list) {
985                                 if (!xfer->tx_buf)
986                                         xfer->tx_buf = master->dummy_tx;
987                                 if (!xfer->rx_buf)
988                                         xfer->rx_buf = master->dummy_rx;
989                         }
990                 }
991         }
992
993         return __spi_map_msg(master, msg);
994 }
995
996 /*
997  * spi_transfer_one_message - Default implementation of transfer_one_message()
998  *
999  * This is a standard implementation of transfer_one_message() for
1000  * drivers which implement a transfer_one() operation.  It provides
1001  * standard handling of delays and chip select management.
1002  */
1003 static int spi_transfer_one_message(struct spi_master *master,
1004                                     struct spi_message *msg)
1005 {
1006         struct spi_transfer *xfer;
1007         bool keep_cs = false;
1008         int ret = 0;
1009         unsigned long long ms = 1;
1010         struct spi_statistics *statm = &master->statistics;
1011         struct spi_statistics *stats = &msg->spi->statistics;
1012
1013         spi_set_cs(msg->spi, true);
1014
1015         SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1016         SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1017
1018         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1019                 trace_spi_transfer_start(msg, xfer);
1020
1021                 spi_statistics_add_transfer_stats(statm, xfer, master);
1022                 spi_statistics_add_transfer_stats(stats, xfer, master);
1023
1024                 if (xfer->tx_buf || xfer->rx_buf) {
1025                         reinit_completion(&master->xfer_completion);
1026
1027                         ret = master->transfer_one(master, msg->spi, xfer);
1028                         if (ret < 0) {
1029                                 SPI_STATISTICS_INCREMENT_FIELD(statm,
1030                                                                errors);
1031                                 SPI_STATISTICS_INCREMENT_FIELD(stats,
1032                                                                errors);
1033                                 dev_err(&msg->spi->dev,
1034                                         "SPI transfer failed: %d\n", ret);
1035                                 goto out;
1036                         }
1037
1038                         if (ret > 0) {
1039                                 ret = 0;
1040                                 ms = 8LL * 1000LL * xfer->len;
1041                                 do_div(ms, xfer->speed_hz);
1042                                 ms += ms + 200; /* some tolerance */
1043
1044                                 if (ms > UINT_MAX)
1045                                         ms = UINT_MAX;
1046
1047                                 ms = wait_for_completion_timeout(&master->xfer_completion,
1048                                                                  msecs_to_jiffies(ms));
1049                         }
1050
1051                         if (ms == 0) {
1052                                 SPI_STATISTICS_INCREMENT_FIELD(statm,
1053                                                                timedout);
1054                                 SPI_STATISTICS_INCREMENT_FIELD(stats,
1055                                                                timedout);
1056                                 dev_err(&msg->spi->dev,
1057                                         "SPI transfer timed out\n");
1058                                 msg->status = -ETIMEDOUT;
1059                         }
1060                 } else {
1061                         if (xfer->len)
1062                                 dev_err(&msg->spi->dev,
1063                                         "Bufferless transfer has length %u\n",
1064                                         xfer->len);
1065                 }
1066
1067                 trace_spi_transfer_stop(msg, xfer);
1068
1069                 if (msg->status != -EINPROGRESS)
1070                         goto out;
1071
1072                 if (xfer->delay_usecs) {
1073                         u16 us = xfer->delay_usecs;
1074
1075                         if (us <= 10)
1076                                 udelay(us);
1077                         else
1078                                 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1079                 }
1080
1081                 if (xfer->cs_change) {
1082                         if (list_is_last(&xfer->transfer_list,
1083                                          &msg->transfers)) {
1084                                 keep_cs = true;
1085                         } else {
1086                                 spi_set_cs(msg->spi, false);
1087                                 udelay(10);
1088                                 spi_set_cs(msg->spi, true);
1089                         }
1090                 }
1091
1092                 msg->actual_length += xfer->len;
1093         }
1094
1095 out:
1096         if (ret != 0 || !keep_cs)
1097                 spi_set_cs(msg->spi, false);
1098
1099         if (msg->status == -EINPROGRESS)
1100                 msg->status = ret;
1101
1102         if (msg->status && master->handle_err)
1103                 master->handle_err(master, msg);
1104
1105         spi_res_release(master, msg);
1106
1107         spi_finalize_current_message(master);
1108
1109         return ret;
1110 }
1111
1112 /**
1113  * spi_finalize_current_transfer - report completion of a transfer
1114  * @master: the master reporting completion
1115  *
1116  * Called by SPI drivers using the core transfer_one_message()
1117  * implementation to notify it that the current interrupt driven
1118  * transfer has finished and the next one may be scheduled.
1119  */
1120 void spi_finalize_current_transfer(struct spi_master *master)
1121 {
1122         complete(&master->xfer_completion);
1123 }
1124 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1125
1126 /**
1127  * __spi_pump_messages - function which processes spi message queue
1128  * @master: master to process queue for
1129  * @in_kthread: true if we are in the context of the message pump thread
1130  *
1131  * This function checks if there is any spi message in the queue that
1132  * needs processing and if so call out to the driver to initialize hardware
1133  * and transfer each message.
1134  *
1135  * Note that it is called both from the kthread itself and also from
1136  * inside spi_sync(); the queue extraction handling at the top of the
1137  * function should deal with this safely.
1138  */
1139 static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
1140 {
1141         unsigned long flags;
1142         bool was_busy = false;
1143         int ret;
1144
1145         /* Lock queue */
1146         spin_lock_irqsave(&master->queue_lock, flags);
1147
1148         /* Make sure we are not already running a message */
1149         if (master->cur_msg) {
1150                 spin_unlock_irqrestore(&master->queue_lock, flags);
1151                 return;
1152         }
1153
1154         /* If another context is idling the device then defer */
1155         if (master->idling) {
1156                 kthread_queue_work(&master->kworker, &master->pump_messages);
1157                 spin_unlock_irqrestore(&master->queue_lock, flags);
1158                 return;
1159         }
1160
1161         /* Check if the queue is idle */
1162         if (list_empty(&master->queue) || !master->running) {
1163                 if (!master->busy) {
1164                         spin_unlock_irqrestore(&master->queue_lock, flags);
1165                         return;
1166                 }
1167
1168                 /* Only do teardown in the thread */
1169                 if (!in_kthread) {
1170                         kthread_queue_work(&master->kworker,
1171                                            &master->pump_messages);
1172                         spin_unlock_irqrestore(&master->queue_lock, flags);
1173                         return;
1174                 }
1175
1176                 master->busy = false;
1177                 master->idling = true;
1178                 spin_unlock_irqrestore(&master->queue_lock, flags);
1179
1180                 kfree(master->dummy_rx);
1181                 master->dummy_rx = NULL;
1182                 kfree(master->dummy_tx);
1183                 master->dummy_tx = NULL;
1184                 if (master->unprepare_transfer_hardware &&
1185                     master->unprepare_transfer_hardware(master))
1186                         dev_err(&master->dev,
1187                                 "failed to unprepare transfer hardware\n");
1188                 if (master->auto_runtime_pm) {
1189                         pm_runtime_mark_last_busy(master->dev.parent);
1190                         pm_runtime_put_autosuspend(master->dev.parent);
1191                 }
1192                 trace_spi_master_idle(master);
1193
1194                 spin_lock_irqsave(&master->queue_lock, flags);
1195                 master->idling = false;
1196                 spin_unlock_irqrestore(&master->queue_lock, flags);
1197                 return;
1198         }
1199
1200         /* Extract head of queue */
1201         master->cur_msg =
1202                 list_first_entry(&master->queue, struct spi_message, queue);
1203
1204         list_del_init(&master->cur_msg->queue);
1205         if (master->busy)
1206                 was_busy = true;
1207         else
1208                 master->busy = true;
1209         spin_unlock_irqrestore(&master->queue_lock, flags);
1210
1211         mutex_lock(&master->io_mutex);
1212
1213         if (!was_busy && master->auto_runtime_pm) {
1214                 ret = pm_runtime_get_sync(master->dev.parent);
1215                 if (ret < 0) {
1216                         dev_err(&master->dev, "Failed to power device: %d\n",
1217                                 ret);
1218                         mutex_unlock(&master->io_mutex);
1219                         return;
1220                 }
1221         }
1222
1223         if (!was_busy)
1224                 trace_spi_master_busy(master);
1225
1226         if (!was_busy && master->prepare_transfer_hardware) {
1227                 ret = master->prepare_transfer_hardware(master);
1228                 if (ret) {
1229                         dev_err(&master->dev,
1230                                 "failed to prepare transfer hardware\n");
1231
1232                         if (master->auto_runtime_pm)
1233                                 pm_runtime_put(master->dev.parent);
1234                         mutex_unlock(&master->io_mutex);
1235                         return;
1236                 }
1237         }
1238
1239         trace_spi_message_start(master->cur_msg);
1240
1241         if (master->prepare_message) {
1242                 ret = master->prepare_message(master, master->cur_msg);
1243                 if (ret) {
1244                         dev_err(&master->dev,
1245                                 "failed to prepare message: %d\n", ret);
1246                         master->cur_msg->status = ret;
1247                         spi_finalize_current_message(master);
1248                         goto out;
1249                 }
1250                 master->cur_msg_prepared = true;
1251         }
1252
1253         ret = spi_map_msg(master, master->cur_msg);
1254         if (ret) {
1255                 master->cur_msg->status = ret;
1256                 spi_finalize_current_message(master);
1257                 goto out;
1258         }
1259
1260         ret = master->transfer_one_message(master, master->cur_msg);
1261         if (ret) {
1262                 dev_err(&master->dev,
1263                         "failed to transfer one message from queue\n");
1264                 goto out;
1265         }
1266
1267 out:
1268         mutex_unlock(&master->io_mutex);
1269
1270         /* Prod the scheduler in case transfer_one() was busy waiting */
1271         if (!ret)
1272                 cond_resched();
1273 }
1274
1275 /**
1276  * spi_pump_messages - kthread work function which processes spi message queue
1277  * @work: pointer to kthread work struct contained in the master struct
1278  */
1279 static void spi_pump_messages(struct kthread_work *work)
1280 {
1281         struct spi_master *master =
1282                 container_of(work, struct spi_master, pump_messages);
1283
1284         __spi_pump_messages(master, true);
1285 }
1286
1287 static int spi_init_queue(struct spi_master *master)
1288 {
1289         struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1290
1291         master->running = false;
1292         master->busy = false;
1293
1294         kthread_init_worker(&master->kworker);
1295         master->kworker_task = kthread_run(kthread_worker_fn,
1296                                            &master->kworker, "%s",
1297                                            dev_name(&master->dev));
1298         if (IS_ERR(master->kworker_task)) {
1299                 dev_err(&master->dev, "failed to create message pump task\n");
1300                 return PTR_ERR(master->kworker_task);
1301         }
1302         kthread_init_work(&master->pump_messages, spi_pump_messages);
1303
1304         /*
1305          * Master config will indicate if this controller should run the
1306          * message pump with high (realtime) priority to reduce the transfer
1307          * latency on the bus by minimising the delay between a transfer
1308          * request and the scheduling of the message pump thread. Without this
1309          * setting the message pump thread will remain at default priority.
1310          */
1311         if (master->rt) {
1312                 dev_info(&master->dev,
1313                         "will run message pump with realtime priority\n");
1314                 sched_setscheduler(master->kworker_task, SCHED_FIFO, &param);
1315         }
1316
1317         return 0;
1318 }
1319
1320 /**
1321  * spi_get_next_queued_message() - called by driver to check for queued
1322  * messages
1323  * @master: the master to check for queued messages
1324  *
1325  * If there are more messages in the queue, the next message is returned from
1326  * this call.
1327  *
1328  * Return: the next message in the queue, else NULL if the queue is empty.
1329  */
1330 struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1331 {
1332         struct spi_message *next;
1333         unsigned long flags;
1334
1335         /* get a pointer to the next message, if any */
1336         spin_lock_irqsave(&master->queue_lock, flags);
1337         next = list_first_entry_or_null(&master->queue, struct spi_message,
1338                                         queue);
1339         spin_unlock_irqrestore(&master->queue_lock, flags);
1340
1341         return next;
1342 }
1343 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1344
1345 /**
1346  * spi_finalize_current_message() - the current message is complete
1347  * @master: the master to return the message to
1348  *
1349  * Called by the driver to notify the core that the message in the front of the
1350  * queue is complete and can be removed from the queue.
1351  */
1352 void spi_finalize_current_message(struct spi_master *master)
1353 {
1354         struct spi_message *mesg;
1355         unsigned long flags;
1356         int ret;
1357
1358         spin_lock_irqsave(&master->queue_lock, flags);
1359         mesg = master->cur_msg;
1360         spin_unlock_irqrestore(&master->queue_lock, flags);
1361
1362         spi_unmap_msg(master, mesg);
1363
1364         if (master->cur_msg_prepared && master->unprepare_message) {
1365                 ret = master->unprepare_message(master, mesg);
1366                 if (ret) {
1367                         dev_err(&master->dev,
1368                                 "failed to unprepare message: %d\n", ret);
1369                 }
1370         }
1371
1372         spin_lock_irqsave(&master->queue_lock, flags);
1373         master->cur_msg = NULL;
1374         master->cur_msg_prepared = false;
1375         kthread_queue_work(&master->kworker, &master->pump_messages);
1376         spin_unlock_irqrestore(&master->queue_lock, flags);
1377
1378         trace_spi_message_done(mesg);
1379
1380         mesg->state = NULL;
1381         if (mesg->complete)
1382                 mesg->complete(mesg->context);
1383 }
1384 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1385
1386 static int spi_start_queue(struct spi_master *master)
1387 {
1388         unsigned long flags;
1389
1390         spin_lock_irqsave(&master->queue_lock, flags);
1391
1392         if (master->running || master->busy) {
1393                 spin_unlock_irqrestore(&master->queue_lock, flags);
1394                 return -EBUSY;
1395         }
1396
1397         master->running = true;
1398         master->cur_msg = NULL;
1399         spin_unlock_irqrestore(&master->queue_lock, flags);
1400
1401         kthread_queue_work(&master->kworker, &master->pump_messages);
1402
1403         return 0;
1404 }
1405
1406 static int spi_stop_queue(struct spi_master *master)
1407 {
1408         unsigned long flags;
1409         unsigned limit = 500;
1410         int ret = 0;
1411
1412         spin_lock_irqsave(&master->queue_lock, flags);
1413
1414         /*
1415          * This is a bit lame, but is optimized for the common execution path.
1416          * A wait_queue on the master->busy could be used, but then the common
1417          * execution path (pump_messages) would be required to call wake_up or
1418          * friends on every SPI message. Do this instead.
1419          */
1420         while ((!list_empty(&master->queue) || master->busy) && limit--) {
1421                 spin_unlock_irqrestore(&master->queue_lock, flags);
1422                 usleep_range(10000, 11000);
1423                 spin_lock_irqsave(&master->queue_lock, flags);
1424         }
1425
1426         if (!list_empty(&master->queue) || master->busy)
1427                 ret = -EBUSY;
1428         else
1429                 master->running = false;
1430
1431         spin_unlock_irqrestore(&master->queue_lock, flags);
1432
1433         if (ret) {
1434                 dev_warn(&master->dev,
1435                          "could not stop message queue\n");
1436                 return ret;
1437         }
1438         return ret;
1439 }
1440
1441 static int spi_destroy_queue(struct spi_master *master)
1442 {
1443         int ret;
1444
1445         ret = spi_stop_queue(master);
1446
1447         /*
1448          * kthread_flush_worker will block until all work is done.
1449          * If the reason that stop_queue timed out is that the work will never
1450          * finish, then it does no good to call flush/stop thread, so
1451          * return anyway.
1452          */
1453         if (ret) {
1454                 dev_err(&master->dev, "problem destroying queue\n");
1455                 return ret;
1456         }
1457
1458         kthread_flush_worker(&master->kworker);
1459         kthread_stop(master->kworker_task);
1460
1461         return 0;
1462 }
1463
1464 static int __spi_queued_transfer(struct spi_device *spi,
1465                                  struct spi_message *msg,
1466                                  bool need_pump)
1467 {
1468         struct spi_master *master = spi->master;
1469         unsigned long flags;
1470
1471         spin_lock_irqsave(&master->queue_lock, flags);
1472
1473         if (!master->running) {
1474                 spin_unlock_irqrestore(&master->queue_lock, flags);
1475                 return -ESHUTDOWN;
1476         }
1477         msg->actual_length = 0;
1478         msg->status = -EINPROGRESS;
1479
1480         list_add_tail(&msg->queue, &master->queue);
1481         if (!master->busy && need_pump)
1482                 kthread_queue_work(&master->kworker, &master->pump_messages);
1483
1484         spin_unlock_irqrestore(&master->queue_lock, flags);
1485         return 0;
1486 }
1487
1488 /**
1489  * spi_queued_transfer - transfer function for queued transfers
1490  * @spi: spi device which is requesting transfer
1491  * @msg: spi message which is to handled is queued to driver queue
1492  *
1493  * Return: zero on success, else a negative error code.
1494  */
1495 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1496 {
1497         return __spi_queued_transfer(spi, msg, true);
1498 }
1499
1500 static int spi_master_initialize_queue(struct spi_master *master)
1501 {
1502         int ret;
1503
1504         master->transfer = spi_queued_transfer;
1505         if (!master->transfer_one_message)
1506                 master->transfer_one_message = spi_transfer_one_message;
1507
1508         /* Initialize and start queue */
1509         ret = spi_init_queue(master);
1510         if (ret) {
1511                 dev_err(&master->dev, "problem initializing queue\n");
1512                 goto err_init_queue;
1513         }
1514         master->queued = true;
1515         ret = spi_start_queue(master);
1516         if (ret) {
1517                 dev_err(&master->dev, "problem starting queue\n");
1518                 goto err_start_queue;
1519         }
1520
1521         return 0;
1522
1523 err_start_queue:
1524         spi_destroy_queue(master);
1525 err_init_queue:
1526         return ret;
1527 }
1528
1529 /*-------------------------------------------------------------------------*/
1530
1531 #if defined(CONFIG_OF)
1532 static int of_spi_parse_dt(struct spi_master *master, struct spi_device *spi,
1533                            struct device_node *nc)
1534 {
1535         u32 value;
1536         int rc;
1537
1538         /* Mode (clock phase/polarity/etc.) */
1539         if (of_find_property(nc, "spi-cpha", NULL))
1540                 spi->mode |= SPI_CPHA;
1541         if (of_find_property(nc, "spi-cpol", NULL))
1542                 spi->mode |= SPI_CPOL;
1543         if (of_find_property(nc, "spi-cs-high", NULL))
1544                 spi->mode |= SPI_CS_HIGH;
1545         if (of_find_property(nc, "spi-3wire", NULL))
1546                 spi->mode |= SPI_3WIRE;
1547         if (of_find_property(nc, "spi-lsb-first", NULL))
1548                 spi->mode |= SPI_LSB_FIRST;
1549
1550         /* Device DUAL/QUAD mode */
1551         if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1552                 switch (value) {
1553                 case 1:
1554                         break;
1555                 case 2:
1556                         spi->mode |= SPI_TX_DUAL;
1557                         break;
1558                 case 4:
1559                         spi->mode |= SPI_TX_QUAD;
1560                         break;
1561                 default:
1562                         dev_warn(&master->dev,
1563                                 "spi-tx-bus-width %d not supported\n",
1564                                 value);
1565                         break;
1566                 }
1567         }
1568
1569         if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1570                 switch (value) {
1571                 case 1:
1572                         break;
1573                 case 2:
1574                         spi->mode |= SPI_RX_DUAL;
1575                         break;
1576                 case 4:
1577                         spi->mode |= SPI_RX_QUAD;
1578                         break;
1579                 default:
1580                         dev_warn(&master->dev,
1581                                 "spi-rx-bus-width %d not supported\n",
1582                                 value);
1583                         break;
1584                 }
1585         }
1586
1587         if (spi_controller_is_slave(master)) {
1588                 if (strcmp(nc->name, "slave")) {
1589                         dev_err(&master->dev, "%s is not called 'slave'\n",
1590                                 nc->full_name);
1591                         return -EINVAL;
1592                 }
1593                 return 0;
1594         }
1595
1596         /* Device address */
1597         rc = of_property_read_u32(nc, "reg", &value);
1598         if (rc) {
1599                 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1600                         nc->full_name, rc);
1601                 return rc;
1602         }
1603         spi->chip_select = value;
1604
1605         /* Device speed */
1606         rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1607         if (rc) {
1608                 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1609                         nc->full_name, rc);
1610                 return rc;
1611         }
1612         spi->max_speed_hz = value;
1613
1614         return 0;
1615 }
1616
1617 static struct spi_device *
1618 of_register_spi_device(struct spi_master *master, struct device_node *nc)
1619 {
1620         struct spi_device *spi;
1621         int rc;
1622
1623         /* Alloc an spi_device */
1624         spi = spi_alloc_device(master);
1625         if (!spi) {
1626                 dev_err(&master->dev, "spi_device alloc error for %s\n",
1627                         nc->full_name);
1628                 rc = -ENOMEM;
1629                 goto err_out;
1630         }
1631
1632         /* Select device driver */
1633         rc = of_modalias_node(nc, spi->modalias,
1634                                 sizeof(spi->modalias));
1635         if (rc < 0) {
1636                 dev_err(&master->dev, "cannot find modalias for %s\n",
1637                         nc->full_name);
1638                 goto err_out;
1639         }
1640
1641         rc = of_spi_parse_dt(master, spi, nc);
1642         if (rc)
1643                 goto err_out;
1644
1645         /* Store a pointer to the node in the device structure */
1646         of_node_get(nc);
1647         spi->dev.of_node = nc;
1648
1649         /* Register the new device */
1650         rc = spi_add_device(spi);
1651         if (rc) {
1652                 dev_err(&master->dev, "spi_device register error %s\n",
1653                         nc->full_name);
1654                 goto err_of_node_put;
1655         }
1656
1657         return spi;
1658
1659 err_of_node_put:
1660         of_node_put(nc);
1661 err_out:
1662         spi_dev_put(spi);
1663         return ERR_PTR(rc);
1664 }
1665
1666 /**
1667  * of_register_spi_devices() - Register child devices onto the SPI bus
1668  * @master:     Pointer to spi_master device
1669  *
1670  * Registers an spi_device for each child node of controller node which
1671  * represents a valid SPI slave.
1672  */
1673 static void of_register_spi_devices(struct spi_master *master)
1674 {
1675         struct spi_device *spi;
1676         struct device_node *nc;
1677
1678         if (!master->dev.of_node)
1679                 return;
1680
1681         for_each_available_child_of_node(master->dev.of_node, nc) {
1682                 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1683                         continue;
1684                 spi = of_register_spi_device(master, nc);
1685                 if (IS_ERR(spi)) {
1686                         dev_warn(&master->dev, "Failed to create SPI device for %s\n",
1687                                 nc->full_name);
1688                         of_node_clear_flag(nc, OF_POPULATED);
1689                 }
1690         }
1691 }
1692 #else
1693 static void of_register_spi_devices(struct spi_master *master) { }
1694 #endif
1695
1696 #ifdef CONFIG_ACPI
1697 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1698 {
1699         struct spi_device *spi = data;
1700         struct spi_master *master = spi->master;
1701
1702         if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1703                 struct acpi_resource_spi_serialbus *sb;
1704
1705                 sb = &ares->data.spi_serial_bus;
1706                 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1707                         /*
1708                          * ACPI DeviceSelection numbering is handled by the
1709                          * host controller driver in Windows and can vary
1710                          * from driver to driver. In Linux we always expect
1711                          * 0 .. max - 1 so we need to ask the driver to
1712                          * translate between the two schemes.
1713                          */
1714                         if (master->fw_translate_cs) {
1715                                 int cs = master->fw_translate_cs(master,
1716                                                 sb->device_selection);
1717                                 if (cs < 0)
1718                                         return cs;
1719                                 spi->chip_select = cs;
1720                         } else {
1721                                 spi->chip_select = sb->device_selection;
1722                         }
1723
1724                         spi->max_speed_hz = sb->connection_speed;
1725
1726                         if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1727                                 spi->mode |= SPI_CPHA;
1728                         if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1729                                 spi->mode |= SPI_CPOL;
1730                         if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1731                                 spi->mode |= SPI_CS_HIGH;
1732                 }
1733         } else if (spi->irq < 0) {
1734                 struct resource r;
1735
1736                 if (acpi_dev_resource_interrupt(ares, 0, &r))
1737                         spi->irq = r.start;
1738         }
1739
1740         /* Always tell the ACPI core to skip this resource */
1741         return 1;
1742 }
1743
1744 static acpi_status acpi_register_spi_device(struct spi_master *master,
1745                                             struct acpi_device *adev)
1746 {
1747         struct list_head resource_list;
1748         struct spi_device *spi;
1749         int ret;
1750
1751         if (acpi_bus_get_status(adev) || !adev->status.present ||
1752             acpi_device_enumerated(adev))
1753                 return AE_OK;
1754
1755         spi = spi_alloc_device(master);
1756         if (!spi) {
1757                 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1758                         dev_name(&adev->dev));
1759                 return AE_NO_MEMORY;
1760         }
1761
1762         ACPI_COMPANION_SET(&spi->dev, adev);
1763         spi->irq = -1;
1764
1765         INIT_LIST_HEAD(&resource_list);
1766         ret = acpi_dev_get_resources(adev, &resource_list,
1767                                      acpi_spi_add_resource, spi);
1768         acpi_dev_free_resource_list(&resource_list);
1769
1770         if (ret < 0 || !spi->max_speed_hz) {
1771                 spi_dev_put(spi);
1772                 return AE_OK;
1773         }
1774
1775         acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
1776                           sizeof(spi->modalias));
1777
1778         if (spi->irq < 0)
1779                 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1780
1781         acpi_device_set_enumerated(adev);
1782
1783         adev->power.flags.ignore_parent = true;
1784         if (spi_add_device(spi)) {
1785                 adev->power.flags.ignore_parent = false;
1786                 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1787                         dev_name(&adev->dev));
1788                 spi_dev_put(spi);
1789         }
1790
1791         return AE_OK;
1792 }
1793
1794 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1795                                        void *data, void **return_value)
1796 {
1797         struct spi_master *master = data;
1798         struct acpi_device *adev;
1799
1800         if (acpi_bus_get_device(handle, &adev))
1801                 return AE_OK;
1802
1803         return acpi_register_spi_device(master, adev);
1804 }
1805
1806 static void acpi_register_spi_devices(struct spi_master *master)
1807 {
1808         acpi_status status;
1809         acpi_handle handle;
1810
1811         handle = ACPI_HANDLE(master->dev.parent);
1812         if (!handle)
1813                 return;
1814
1815         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1816                                      acpi_spi_add_device, NULL,
1817                                      master, NULL);
1818         if (ACPI_FAILURE(status))
1819                 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1820 }
1821 #else
1822 static inline void acpi_register_spi_devices(struct spi_master *master) {}
1823 #endif /* CONFIG_ACPI */
1824
1825 static void spi_master_release(struct device *dev)
1826 {
1827         struct spi_master *master;
1828
1829         master = container_of(dev, struct spi_master, dev);
1830         kfree(master);
1831 }
1832
1833 static struct class spi_master_class = {
1834         .name           = "spi_master",
1835         .owner          = THIS_MODULE,
1836         .dev_release    = spi_master_release,
1837         .dev_groups     = spi_master_groups,
1838 };
1839
1840 #ifdef CONFIG_SPI_SLAVE
1841 /**
1842  * spi_slave_abort - abort the ongoing transfer request on an SPI slave
1843  *                   controller
1844  * @spi: device used for the current transfer
1845  */
1846 int spi_slave_abort(struct spi_device *spi)
1847 {
1848         struct spi_master *master = spi->master;
1849
1850         if (spi_controller_is_slave(master) && master->slave_abort)
1851                 return master->slave_abort(master);
1852
1853         return -ENOTSUPP;
1854 }
1855 EXPORT_SYMBOL_GPL(spi_slave_abort);
1856
1857 static int match_true(struct device *dev, void *data)
1858 {
1859         return 1;
1860 }
1861
1862 static ssize_t spi_slave_show(struct device *dev,
1863                               struct device_attribute *attr, char *buf)
1864 {
1865         struct spi_master *ctlr = container_of(dev, struct spi_master, dev);
1866         struct device *child;
1867
1868         child = device_find_child(&ctlr->dev, NULL, match_true);
1869         return sprintf(buf, "%s\n",
1870                        child ? to_spi_device(child)->modalias : NULL);
1871 }
1872
1873 static ssize_t spi_slave_store(struct device *dev,
1874                                struct device_attribute *attr, const char *buf,
1875                                size_t count)
1876 {
1877         struct spi_master *ctlr = container_of(dev, struct spi_master, dev);
1878         struct spi_device *spi;
1879         struct device *child;
1880         char name[32];
1881         int rc;
1882
1883         rc = sscanf(buf, "%31s", name);
1884         if (rc != 1 || !name[0])
1885                 return -EINVAL;
1886
1887         child = device_find_child(&ctlr->dev, NULL, match_true);
1888         if (child) {
1889                 /* Remove registered slave */
1890                 device_unregister(child);
1891                 put_device(child);
1892         }
1893
1894         if (strcmp(name, "(null)")) {
1895                 /* Register new slave */
1896                 spi = spi_alloc_device(ctlr);
1897                 if (!spi)
1898                         return -ENOMEM;
1899
1900                 strlcpy(spi->modalias, name, sizeof(spi->modalias));
1901
1902                 rc = spi_add_device(spi);
1903                 if (rc) {
1904                         spi_dev_put(spi);
1905                         return rc;
1906                 }
1907         }
1908
1909         return count;
1910 }
1911
1912 static DEVICE_ATTR(slave, 0644, spi_slave_show, spi_slave_store);
1913
1914 static struct attribute *spi_slave_attrs[] = {
1915         &dev_attr_slave.attr,
1916         NULL,
1917 };
1918
1919 static const struct attribute_group spi_slave_group = {
1920         .attrs = spi_slave_attrs,
1921 };
1922
1923 static const struct attribute_group *spi_slave_groups[] = {
1924         &spi_master_statistics_group,
1925         &spi_slave_group,
1926         NULL,
1927 };
1928
1929 static struct class spi_slave_class = {
1930         .name           = "spi_slave",
1931         .owner          = THIS_MODULE,
1932         .dev_release    = spi_master_release,
1933         .dev_groups     = spi_slave_groups,
1934 };
1935 #else
1936 extern struct class spi_slave_class;    /* dummy */
1937 #endif
1938
1939 /**
1940  * __spi_alloc_controller - allocate an SPI master or slave controller
1941  * @dev: the controller, possibly using the platform_bus
1942  * @size: how much zeroed driver-private data to allocate; the pointer to this
1943  *      memory is in the driver_data field of the returned device,
1944  *      accessible with spi_master_get_devdata().
1945  * @slave: flag indicating whether to allocate an SPI master (false) or SPI
1946  *      slave (true) controller
1947  * Context: can sleep
1948  *
1949  * This call is used only by SPI controller drivers, which are the
1950  * only ones directly touching chip registers.  It's how they allocate
1951  * an spi_master structure, prior to calling spi_register_master().
1952  *
1953  * This must be called from context that can sleep.
1954  *
1955  * The caller is responsible for assigning the bus number and initializing the
1956  * controller's methods before calling spi_register_master(); and (after errors
1957  * adding the device) calling spi_master_put() to prevent a memory leak.
1958  *
1959  * Return: the SPI controller structure on success, else NULL.
1960  */
1961 struct spi_master *__spi_alloc_controller(struct device *dev,
1962                                           unsigned int size, bool slave)
1963 {
1964         struct spi_master       *master;
1965
1966         if (!dev)
1967                 return NULL;
1968
1969         master = kzalloc(size + sizeof(*master), GFP_KERNEL);
1970         if (!master)
1971                 return NULL;
1972
1973         device_initialize(&master->dev);
1974         master->bus_num = -1;
1975         master->num_chipselect = 1;
1976         master->slave = slave;
1977         if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
1978                 master->dev.class = &spi_slave_class;
1979         else
1980                 master->dev.class = &spi_master_class;
1981         master->dev.parent = dev;
1982         pm_suspend_ignore_children(&master->dev, true);
1983         spi_master_set_devdata(master, &master[1]);
1984
1985         return master;
1986 }
1987 EXPORT_SYMBOL_GPL(__spi_alloc_controller);
1988
1989 #ifdef CONFIG_OF
1990 static int of_spi_register_master(struct spi_master *master)
1991 {
1992         int nb, i, *cs;
1993         struct device_node *np = master->dev.of_node;
1994
1995         if (!np)
1996                 return 0;
1997
1998         nb = of_gpio_named_count(np, "cs-gpios");
1999         master->num_chipselect = max_t(int, nb, master->num_chipselect);
2000
2001         /* Return error only for an incorrectly formed cs-gpios property */
2002         if (nb == 0 || nb == -ENOENT)
2003                 return 0;
2004         else if (nb < 0)
2005                 return nb;
2006
2007         cs = devm_kzalloc(&master->dev,
2008                           sizeof(int) * master->num_chipselect,
2009                           GFP_KERNEL);
2010         master->cs_gpios = cs;
2011
2012         if (!master->cs_gpios)
2013                 return -ENOMEM;
2014
2015         for (i = 0; i < master->num_chipselect; i++)
2016                 cs[i] = -ENOENT;
2017
2018         for (i = 0; i < nb; i++)
2019                 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2020
2021         return 0;
2022 }
2023 #else
2024 static int of_spi_register_master(struct spi_master *master)
2025 {
2026         return 0;
2027 }
2028 #endif
2029
2030 /**
2031  * spi_register_master - register SPI master controller
2032  * @master: initialized master, originally from spi_alloc_master()
2033  * Context: can sleep
2034  *
2035  * SPI master controllers connect to their drivers using some non-SPI bus,
2036  * such as the platform bus.  The final stage of probe() in that code
2037  * includes calling spi_register_master() to hook up to this SPI bus glue.
2038  *
2039  * SPI controllers use board specific (often SOC specific) bus numbers,
2040  * and board-specific addressing for SPI devices combines those numbers
2041  * with chip select numbers.  Since SPI does not directly support dynamic
2042  * device identification, boards need configuration tables telling which
2043  * chip is at which address.
2044  *
2045  * This must be called from context that can sleep.  It returns zero on
2046  * success, else a negative error code (dropping the master's refcount).
2047  * After a successful return, the caller is responsible for calling
2048  * spi_unregister_master().
2049  *
2050  * Return: zero on success, else a negative error code.
2051  */
2052 int spi_register_master(struct spi_master *master)
2053 {
2054         static atomic_t         dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
2055         struct device           *dev = master->dev.parent;
2056         struct boardinfo        *bi;
2057         int                     status = -ENODEV;
2058         int                     dynamic = 0;
2059
2060         if (!dev)
2061                 return -ENODEV;
2062
2063         if (!spi_controller_is_slave(master)) {
2064                 status = of_spi_register_master(master);
2065                 if (status)
2066                         return status;
2067         }
2068
2069         /* even if it's just one always-selected device, there must
2070          * be at least one chipselect
2071          */
2072         if (master->num_chipselect == 0)
2073                 return -EINVAL;
2074
2075         if ((master->bus_num < 0) && master->dev.of_node)
2076                 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
2077
2078         /* convention:  dynamically assigned bus IDs count down from the max */
2079         if (master->bus_num < 0) {
2080                 /* FIXME switch to an IDR based scheme, something like
2081                  * I2C now uses, so we can't run out of "dynamic" IDs
2082                  */
2083                 master->bus_num = atomic_dec_return(&dyn_bus_id);
2084                 dynamic = 1;
2085         }
2086
2087         INIT_LIST_HEAD(&master->queue);
2088         spin_lock_init(&master->queue_lock);
2089         spin_lock_init(&master->bus_lock_spinlock);
2090         mutex_init(&master->bus_lock_mutex);
2091         mutex_init(&master->io_mutex);
2092         master->bus_lock_flag = 0;
2093         init_completion(&master->xfer_completion);
2094         if (!master->max_dma_len)
2095                 master->max_dma_len = INT_MAX;
2096
2097         /* register the device, then userspace will see it.
2098          * registration fails if the bus ID is in use.
2099          */
2100         dev_set_name(&master->dev, "spi%u", master->bus_num);
2101         status = device_add(&master->dev);
2102         if (status < 0)
2103                 goto done;
2104         dev_dbg(dev, "registered %s %s%s\n",
2105                         spi_controller_is_slave(master) ? "slave" : "master",
2106                         dev_name(&master->dev), dynamic ? " (dynamic)" : "");
2107
2108         /* If we're using a queued driver, start the queue */
2109         if (master->transfer)
2110                 dev_info(dev, "master is unqueued, this is deprecated\n");
2111         else {
2112                 status = spi_master_initialize_queue(master);
2113                 if (status) {
2114                         device_del(&master->dev);
2115                         goto done;
2116                 }
2117         }
2118         /* add statistics */
2119         spin_lock_init(&master->statistics.lock);
2120
2121         mutex_lock(&board_lock);
2122         list_add_tail(&master->list, &spi_master_list);
2123         list_for_each_entry(bi, &board_list, list)
2124                 spi_match_master_to_boardinfo(master, &bi->board_info);
2125         mutex_unlock(&board_lock);
2126
2127         /* Register devices from the device tree and ACPI */
2128         of_register_spi_devices(master);
2129         acpi_register_spi_devices(master);
2130 done:
2131         return status;
2132 }
2133 EXPORT_SYMBOL_GPL(spi_register_master);
2134
2135 static void devm_spi_unregister(struct device *dev, void *res)
2136 {
2137         spi_unregister_master(*(struct spi_master **)res);
2138 }
2139
2140 /**
2141  * devm_spi_register_master - register managed SPI master controller
2142  * @dev:    device managing SPI master
2143  * @master: initialized master, originally from spi_alloc_master()
2144  * Context: can sleep
2145  *
2146  * Register a SPI device as with spi_register_master() which will
2147  * automatically be unregister
2148  *
2149  * Return: zero on success, else a negative error code.
2150  */
2151 int devm_spi_register_master(struct device *dev, struct spi_master *master)
2152 {
2153         struct spi_master **ptr;
2154         int ret;
2155
2156         ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2157         if (!ptr)
2158                 return -ENOMEM;
2159
2160         ret = spi_register_master(master);
2161         if (!ret) {
2162                 *ptr = master;
2163                 devres_add(dev, ptr);
2164         } else {
2165                 devres_free(ptr);
2166         }
2167
2168         return ret;
2169 }
2170 EXPORT_SYMBOL_GPL(devm_spi_register_master);
2171
2172 static int __unregister(struct device *dev, void *null)
2173 {
2174         spi_unregister_device(to_spi_device(dev));
2175         return 0;
2176 }
2177
2178 /**
2179  * spi_unregister_master - unregister SPI master controller
2180  * @master: the master being unregistered
2181  * Context: can sleep
2182  *
2183  * This call is used only by SPI master controller drivers, which are the
2184  * only ones directly touching chip registers.
2185  *
2186  * This must be called from context that can sleep.
2187  */
2188 void spi_unregister_master(struct spi_master *master)
2189 {
2190         int dummy;
2191
2192         if (master->queued) {
2193                 if (spi_destroy_queue(master))
2194                         dev_err(&master->dev, "queue remove failed\n");
2195         }
2196
2197         mutex_lock(&board_lock);
2198         list_del(&master->list);
2199         mutex_unlock(&board_lock);
2200
2201         dummy = device_for_each_child(&master->dev, NULL, __unregister);
2202         device_unregister(&master->dev);
2203 }
2204 EXPORT_SYMBOL_GPL(spi_unregister_master);
2205
2206 int spi_master_suspend(struct spi_master *master)
2207 {
2208         int ret;
2209
2210         /* Basically no-ops for non-queued masters */
2211         if (!master->queued)
2212                 return 0;
2213
2214         ret = spi_stop_queue(master);
2215         if (ret)
2216                 dev_err(&master->dev, "queue stop failed\n");
2217
2218         return ret;
2219 }
2220 EXPORT_SYMBOL_GPL(spi_master_suspend);
2221
2222 int spi_master_resume(struct spi_master *master)
2223 {
2224         int ret;
2225
2226         if (!master->queued)
2227                 return 0;
2228
2229         ret = spi_start_queue(master);
2230         if (ret)
2231                 dev_err(&master->dev, "queue restart failed\n");
2232
2233         return ret;
2234 }
2235 EXPORT_SYMBOL_GPL(spi_master_resume);
2236
2237 static int __spi_master_match(struct device *dev, const void *data)
2238 {
2239         struct spi_master *m;
2240         const u16 *bus_num = data;
2241
2242         m = container_of(dev, struct spi_master, dev);
2243         return m->bus_num == *bus_num;
2244 }
2245
2246 /**
2247  * spi_busnum_to_master - look up master associated with bus_num
2248  * @bus_num: the master's bus number
2249  * Context: can sleep
2250  *
2251  * This call may be used with devices that are registered after
2252  * arch init time.  It returns a refcounted pointer to the relevant
2253  * spi_master (which the caller must release), or NULL if there is
2254  * no such master registered.
2255  *
2256  * Return: the SPI master structure on success, else NULL.
2257  */
2258 struct spi_master *spi_busnum_to_master(u16 bus_num)
2259 {
2260         struct device           *dev;
2261         struct spi_master       *master = NULL;
2262
2263         dev = class_find_device(&spi_master_class, NULL, &bus_num,
2264                                 __spi_master_match);
2265         if (dev)
2266                 master = container_of(dev, struct spi_master, dev);
2267         /* reference got in class_find_device */
2268         return master;
2269 }
2270 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2271
2272 /*-------------------------------------------------------------------------*/
2273
2274 /* Core methods for SPI resource management */
2275
2276 /**
2277  * spi_res_alloc - allocate a spi resource that is life-cycle managed
2278  *                 during the processing of a spi_message while using
2279  *                 spi_transfer_one
2280  * @spi:     the spi device for which we allocate memory
2281  * @release: the release code to execute for this resource
2282  * @size:    size to alloc and return
2283  * @gfp:     GFP allocation flags
2284  *
2285  * Return: the pointer to the allocated data
2286  *
2287  * This may get enhanced in the future to allocate from a memory pool
2288  * of the @spi_device or @spi_master to avoid repeated allocations.
2289  */
2290 void *spi_res_alloc(struct spi_device *spi,
2291                     spi_res_release_t release,
2292                     size_t size, gfp_t gfp)
2293 {
2294         struct spi_res *sres;
2295
2296         sres = kzalloc(sizeof(*sres) + size, gfp);
2297         if (!sres)
2298                 return NULL;
2299
2300         INIT_LIST_HEAD(&sres->entry);
2301         sres->release = release;
2302
2303         return sres->data;
2304 }
2305 EXPORT_SYMBOL_GPL(spi_res_alloc);
2306
2307 /**
2308  * spi_res_free - free an spi resource
2309  * @res: pointer to the custom data of a resource
2310  *
2311  */
2312 void spi_res_free(void *res)
2313 {
2314         struct spi_res *sres = container_of(res, struct spi_res, data);
2315
2316         if (!res)
2317                 return;
2318
2319         WARN_ON(!list_empty(&sres->entry));
2320         kfree(sres);
2321 }
2322 EXPORT_SYMBOL_GPL(spi_res_free);
2323
2324 /**
2325  * spi_res_add - add a spi_res to the spi_message
2326  * @message: the spi message
2327  * @res:     the spi_resource
2328  */
2329 void spi_res_add(struct spi_message *message, void *res)
2330 {
2331         struct spi_res *sres = container_of(res, struct spi_res, data);
2332
2333         WARN_ON(!list_empty(&sres->entry));
2334         list_add_tail(&sres->entry, &message->resources);
2335 }
2336 EXPORT_SYMBOL_GPL(spi_res_add);
2337
2338 /**
2339  * spi_res_release - release all spi resources for this message
2340  * @master:  the @spi_master
2341  * @message: the @spi_message
2342  */
2343 void spi_res_release(struct spi_master *master,
2344                      struct spi_message *message)
2345 {
2346         struct spi_res *res;
2347
2348         while (!list_empty(&message->resources)) {
2349                 res = list_last_entry(&message->resources,
2350                                       struct spi_res, entry);
2351
2352                 if (res->release)
2353                         res->release(master, message, res->data);
2354
2355                 list_del(&res->entry);
2356
2357                 kfree(res);
2358         }
2359 }
2360 EXPORT_SYMBOL_GPL(spi_res_release);
2361
2362 /*-------------------------------------------------------------------------*/
2363
2364 /* Core methods for spi_message alterations */
2365
2366 static void __spi_replace_transfers_release(struct spi_master *master,
2367                                             struct spi_message *msg,
2368                                             void *res)
2369 {
2370         struct spi_replaced_transfers *rxfer = res;
2371         size_t i;
2372
2373         /* call extra callback if requested */
2374         if (rxfer->release)
2375                 rxfer->release(master, msg, res);
2376
2377         /* insert replaced transfers back into the message */
2378         list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2379
2380         /* remove the formerly inserted entries */
2381         for (i = 0; i < rxfer->inserted; i++)
2382                 list_del(&rxfer->inserted_transfers[i].transfer_list);
2383 }
2384
2385 /**
2386  * spi_replace_transfers - replace transfers with several transfers
2387  *                         and register change with spi_message.resources
2388  * @msg:           the spi_message we work upon
2389  * @xfer_first:    the first spi_transfer we want to replace
2390  * @remove:        number of transfers to remove
2391  * @insert:        the number of transfers we want to insert instead
2392  * @release:       extra release code necessary in some circumstances
2393  * @extradatasize: extra data to allocate (with alignment guarantees
2394  *                 of struct @spi_transfer)
2395  * @gfp:           gfp flags
2396  *
2397  * Returns: pointer to @spi_replaced_transfers,
2398  *          PTR_ERR(...) in case of errors.
2399  */
2400 struct spi_replaced_transfers *spi_replace_transfers(
2401         struct spi_message *msg,
2402         struct spi_transfer *xfer_first,
2403         size_t remove,
2404         size_t insert,
2405         spi_replaced_release_t release,
2406         size_t extradatasize,
2407         gfp_t gfp)
2408 {
2409         struct spi_replaced_transfers *rxfer;
2410         struct spi_transfer *xfer;
2411         size_t i;
2412
2413         /* allocate the structure using spi_res */
2414         rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2415                               insert * sizeof(struct spi_transfer)
2416                               + sizeof(struct spi_replaced_transfers)
2417                               + extradatasize,
2418                               gfp);
2419         if (!rxfer)
2420                 return ERR_PTR(-ENOMEM);
2421
2422         /* the release code to invoke before running the generic release */
2423         rxfer->release = release;
2424
2425         /* assign extradata */
2426         if (extradatasize)
2427                 rxfer->extradata =
2428                         &rxfer->inserted_transfers[insert];
2429
2430         /* init the replaced_transfers list */
2431         INIT_LIST_HEAD(&rxfer->replaced_transfers);
2432
2433         /* assign the list_entry after which we should reinsert
2434          * the @replaced_transfers - it may be spi_message.messages!
2435          */
2436         rxfer->replaced_after = xfer_first->transfer_list.prev;
2437
2438         /* remove the requested number of transfers */
2439         for (i = 0; i < remove; i++) {
2440                 /* if the entry after replaced_after it is msg->transfers
2441                  * then we have been requested to remove more transfers
2442                  * than are in the list
2443                  */
2444                 if (rxfer->replaced_after->next == &msg->transfers) {
2445                         dev_err(&msg->spi->dev,
2446                                 "requested to remove more spi_transfers than are available\n");
2447                         /* insert replaced transfers back into the message */
2448                         list_splice(&rxfer->replaced_transfers,
2449                                     rxfer->replaced_after);
2450
2451                         /* free the spi_replace_transfer structure */
2452                         spi_res_free(rxfer);
2453
2454                         /* and return with an error */
2455                         return ERR_PTR(-EINVAL);
2456                 }
2457
2458                 /* remove the entry after replaced_after from list of
2459                  * transfers and add it to list of replaced_transfers
2460                  */
2461                 list_move_tail(rxfer->replaced_after->next,
2462                                &rxfer->replaced_transfers);
2463         }
2464
2465         /* create copy of the given xfer with identical settings
2466          * based on the first transfer to get removed
2467          */
2468         for (i = 0; i < insert; i++) {
2469                 /* we need to run in reverse order */
2470                 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2471
2472                 /* copy all spi_transfer data */
2473                 memcpy(xfer, xfer_first, sizeof(*xfer));
2474
2475                 /* add to list */
2476                 list_add(&xfer->transfer_list, rxfer->replaced_after);
2477
2478                 /* clear cs_change and delay_usecs for all but the last */
2479                 if (i) {
2480                         xfer->cs_change = false;
2481                         xfer->delay_usecs = 0;
2482                 }
2483         }
2484
2485         /* set up inserted */
2486         rxfer->inserted = insert;
2487
2488         /* and register it with spi_res/spi_message */
2489         spi_res_add(msg, rxfer);
2490
2491         return rxfer;
2492 }
2493 EXPORT_SYMBOL_GPL(spi_replace_transfers);
2494
2495 static int __spi_split_transfer_maxsize(struct spi_master *master,
2496                                         struct spi_message *msg,
2497                                         struct spi_transfer **xferp,
2498                                         size_t maxsize,
2499                                         gfp_t gfp)
2500 {
2501         struct spi_transfer *xfer = *xferp, *xfers;
2502         struct spi_replaced_transfers *srt;
2503         size_t offset;
2504         size_t count, i;
2505
2506         /* warn once about this fact that we are splitting a transfer */
2507         dev_warn_once(&msg->spi->dev,
2508                       "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2509                       xfer->len, maxsize);
2510
2511         /* calculate how many we have to replace */
2512         count = DIV_ROUND_UP(xfer->len, maxsize);
2513
2514         /* create replacement */
2515         srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
2516         if (IS_ERR(srt))
2517                 return PTR_ERR(srt);
2518         xfers = srt->inserted_transfers;
2519
2520         /* now handle each of those newly inserted spi_transfers
2521          * note that the replacements spi_transfers all are preset
2522          * to the same values as *xferp, so tx_buf, rx_buf and len
2523          * are all identical (as well as most others)
2524          * so we just have to fix up len and the pointers.
2525          *
2526          * this also includes support for the depreciated
2527          * spi_message.is_dma_mapped interface
2528          */
2529
2530         /* the first transfer just needs the length modified, so we
2531          * run it outside the loop
2532          */
2533         xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
2534
2535         /* all the others need rx_buf/tx_buf also set */
2536         for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2537                 /* update rx_buf, tx_buf and dma */
2538                 if (xfers[i].rx_buf)
2539                         xfers[i].rx_buf += offset;
2540                 if (xfers[i].rx_dma)
2541                         xfers[i].rx_dma += offset;
2542                 if (xfers[i].tx_buf)
2543                         xfers[i].tx_buf += offset;
2544                 if (xfers[i].tx_dma)
2545                         xfers[i].tx_dma += offset;
2546
2547                 /* update length */
2548                 xfers[i].len = min(maxsize, xfers[i].len - offset);
2549         }
2550
2551         /* we set up xferp to the last entry we have inserted,
2552          * so that we skip those already split transfers
2553          */
2554         *xferp = &xfers[count - 1];
2555
2556         /* increment statistics counters */
2557         SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2558                                        transfers_split_maxsize);
2559         SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2560                                        transfers_split_maxsize);
2561
2562         return 0;
2563 }
2564
2565 /**
2566  * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2567  *                              when an individual transfer exceeds a
2568  *                              certain size
2569  * @master:    the @spi_master for this transfer
2570  * @msg:   the @spi_message to transform
2571  * @maxsize:  the maximum when to apply this
2572  * @gfp: GFP allocation flags
2573  *
2574  * Return: status of transformation
2575  */
2576 int spi_split_transfers_maxsize(struct spi_master *master,
2577                                 struct spi_message *msg,
2578                                 size_t maxsize,
2579                                 gfp_t gfp)
2580 {
2581         struct spi_transfer *xfer;
2582         int ret;
2583
2584         /* iterate over the transfer_list,
2585          * but note that xfer is advanced to the last transfer inserted
2586          * to avoid checking sizes again unnecessarily (also xfer does
2587          * potentiall belong to a different list by the time the
2588          * replacement has happened
2589          */
2590         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2591                 if (xfer->len > maxsize) {
2592                         ret = __spi_split_transfer_maxsize(
2593                                 master, msg, &xfer, maxsize, gfp);
2594                         if (ret)
2595                                 return ret;
2596                 }
2597         }
2598
2599         return 0;
2600 }
2601 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2602
2603 /*-------------------------------------------------------------------------*/
2604
2605 /* Core methods for SPI master protocol drivers.  Some of the
2606  * other core methods are currently defined as inline functions.
2607  */
2608
2609 static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2610 {
2611         if (master->bits_per_word_mask) {
2612                 /* Only 32 bits fit in the mask */
2613                 if (bits_per_word > 32)
2614                         return -EINVAL;
2615                 if (!(master->bits_per_word_mask &
2616                                 SPI_BPW_MASK(bits_per_word)))
2617                         return -EINVAL;
2618         }
2619
2620         return 0;
2621 }
2622
2623 /**
2624  * spi_setup - setup SPI mode and clock rate
2625  * @spi: the device whose settings are being modified
2626  * Context: can sleep, and no requests are queued to the device
2627  *
2628  * SPI protocol drivers may need to update the transfer mode if the
2629  * device doesn't work with its default.  They may likewise need
2630  * to update clock rates or word sizes from initial values.  This function
2631  * changes those settings, and must be called from a context that can sleep.
2632  * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2633  * effect the next time the device is selected and data is transferred to
2634  * or from it.  When this function returns, the spi device is deselected.
2635  *
2636  * Note that this call will fail if the protocol driver specifies an option
2637  * that the underlying controller or its driver does not support.  For
2638  * example, not all hardware supports wire transfers using nine bit words,
2639  * LSB-first wire encoding, or active-high chipselects.
2640  *
2641  * Return: zero on success, else a negative error code.
2642  */
2643 int spi_setup(struct spi_device *spi)
2644 {
2645         unsigned        bad_bits, ugly_bits;
2646         int             status;
2647
2648         /* check mode to prevent that DUAL and QUAD set at the same time
2649          */
2650         if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2651                 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2652                 dev_err(&spi->dev,
2653                 "setup: can not select dual and quad at the same time\n");
2654                 return -EINVAL;
2655         }
2656         /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2657          */
2658         if ((spi->mode & SPI_3WIRE) && (spi->mode &
2659                 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2660                 return -EINVAL;
2661         /* help drivers fail *cleanly* when they need options
2662          * that aren't supported with their current master
2663          */
2664         bad_bits = spi->mode & ~spi->master->mode_bits;
2665         ugly_bits = bad_bits &
2666                     (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2667         if (ugly_bits) {
2668                 dev_warn(&spi->dev,
2669                          "setup: ignoring unsupported mode bits %x\n",
2670                          ugly_bits);
2671                 spi->mode &= ~ugly_bits;
2672                 bad_bits &= ~ugly_bits;
2673         }
2674         if (bad_bits) {
2675                 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
2676                         bad_bits);
2677                 return -EINVAL;
2678         }
2679
2680         if (!spi->bits_per_word)
2681                 spi->bits_per_word = 8;
2682
2683         status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2684         if (status)
2685                 return status;
2686
2687         if (!spi->max_speed_hz)
2688                 spi->max_speed_hz = spi->master->max_speed_hz;
2689
2690         if (spi->master->setup)
2691                 status = spi->master->setup(spi);
2692
2693         spi_set_cs(spi, false);
2694
2695         dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2696                         (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2697                         (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2698                         (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2699                         (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2700                         (spi->mode & SPI_LOOP) ? "loopback, " : "",
2701                         spi->bits_per_word, spi->max_speed_hz,
2702                         status);
2703
2704         return status;
2705 }
2706 EXPORT_SYMBOL_GPL(spi_setup);
2707
2708 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
2709 {
2710         struct spi_master *master = spi->master;
2711         struct spi_transfer *xfer;
2712         int w_size;
2713
2714         if (list_empty(&message->transfers))
2715                 return -EINVAL;
2716
2717         /* Half-duplex links include original MicroWire, and ones with
2718          * only one data pin like SPI_3WIRE (switches direction) or where
2719          * either MOSI or MISO is missing.  They can also be caused by
2720          * software limitations.
2721          */
2722         if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2723                         || (spi->mode & SPI_3WIRE)) {
2724                 unsigned flags = master->flags;
2725
2726                 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2727                         if (xfer->rx_buf && xfer->tx_buf)
2728                                 return -EINVAL;
2729                         if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2730                                 return -EINVAL;
2731                         if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2732                                 return -EINVAL;
2733                 }
2734         }
2735
2736         /**
2737          * Set transfer bits_per_word and max speed as spi device default if
2738          * it is not set for this transfer.
2739          * Set transfer tx_nbits and rx_nbits as single transfer default
2740          * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2741          */
2742         message->frame_length = 0;
2743         list_for_each_entry(xfer, &message->transfers, transfer_list) {
2744                 message->frame_length += xfer->len;
2745                 if (!xfer->bits_per_word)
2746                         xfer->bits_per_word = spi->bits_per_word;
2747
2748                 if (!xfer->speed_hz)
2749                         xfer->speed_hz = spi->max_speed_hz;
2750                 if (!xfer->speed_hz)
2751                         xfer->speed_hz = master->max_speed_hz;
2752
2753                 if (master->max_speed_hz &&
2754                     xfer->speed_hz > master->max_speed_hz)
2755                         xfer->speed_hz = master->max_speed_hz;
2756
2757                 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2758                         return -EINVAL;
2759
2760                 /*
2761                  * SPI transfer length should be multiple of SPI word size
2762                  * where SPI word size should be power-of-two multiple
2763                  */
2764                 if (xfer->bits_per_word <= 8)
2765                         w_size = 1;
2766                 else if (xfer->bits_per_word <= 16)
2767                         w_size = 2;
2768                 else
2769                         w_size = 4;
2770
2771                 /* No partial transfers accepted */
2772                 if (xfer->len % w_size)
2773                         return -EINVAL;
2774
2775                 if (xfer->speed_hz && master->min_speed_hz &&
2776                     xfer->speed_hz < master->min_speed_hz)
2777                         return -EINVAL;
2778
2779                 if (xfer->tx_buf && !xfer->tx_nbits)
2780                         xfer->tx_nbits = SPI_NBITS_SINGLE;
2781                 if (xfer->rx_buf && !xfer->rx_nbits)
2782                         xfer->rx_nbits = SPI_NBITS_SINGLE;
2783                 /* check transfer tx/rx_nbits:
2784                  * 1. check the value matches one of single, dual and quad
2785                  * 2. check tx/rx_nbits match the mode in spi_device
2786                  */
2787                 if (xfer->tx_buf) {
2788                         if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2789                                 xfer->tx_nbits != SPI_NBITS_DUAL &&
2790                                 xfer->tx_nbits != SPI_NBITS_QUAD)
2791                                 return -EINVAL;
2792                         if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2793                                 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2794                                 return -EINVAL;
2795                         if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2796                                 !(spi->mode & SPI_TX_QUAD))
2797                                 return -EINVAL;
2798                 }
2799                 /* check transfer rx_nbits */
2800                 if (xfer->rx_buf) {
2801                         if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2802                                 xfer->rx_nbits != SPI_NBITS_DUAL &&
2803                                 xfer->rx_nbits != SPI_NBITS_QUAD)
2804                                 return -EINVAL;
2805                         if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2806                                 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2807                                 return -EINVAL;
2808                         if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2809                                 !(spi->mode & SPI_RX_QUAD))
2810                                 return -EINVAL;
2811                 }
2812         }
2813
2814         message->status = -EINPROGRESS;
2815
2816         return 0;
2817 }
2818
2819 static int __spi_async(struct spi_device *spi, struct spi_message *message)
2820 {
2821         struct spi_master *master = spi->master;
2822
2823         message->spi = spi;
2824
2825         SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2826         SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2827
2828         trace_spi_message_submit(message);
2829
2830         return master->transfer(spi, message);
2831 }
2832
2833 /**
2834  * spi_async - asynchronous SPI transfer
2835  * @spi: device with which data will be exchanged
2836  * @message: describes the data transfers, including completion callback
2837  * Context: any (irqs may be blocked, etc)
2838  *
2839  * This call may be used in_irq and other contexts which can't sleep,
2840  * as well as from task contexts which can sleep.
2841  *
2842  * The completion callback is invoked in a context which can't sleep.
2843  * Before that invocation, the value of message->status is undefined.
2844  * When the callback is issued, message->status holds either zero (to
2845  * indicate complete success) or a negative error code.  After that
2846  * callback returns, the driver which issued the transfer request may
2847  * deallocate the associated memory; it's no longer in use by any SPI
2848  * core or controller driver code.
2849  *
2850  * Note that although all messages to a spi_device are handled in
2851  * FIFO order, messages may go to different devices in other orders.
2852  * Some device might be higher priority, or have various "hard" access
2853  * time requirements, for example.
2854  *
2855  * On detection of any fault during the transfer, processing of
2856  * the entire message is aborted, and the device is deselected.
2857  * Until returning from the associated message completion callback,
2858  * no other spi_message queued to that device will be processed.
2859  * (This rule applies equally to all the synchronous transfer calls,
2860  * which are wrappers around this core asynchronous primitive.)
2861  *
2862  * Return: zero on success, else a negative error code.
2863  */
2864 int spi_async(struct spi_device *spi, struct spi_message *message)
2865 {
2866         struct spi_master *master = spi->master;
2867         int ret;
2868         unsigned long flags;
2869
2870         ret = __spi_validate(spi, message);
2871         if (ret != 0)
2872                 return ret;
2873
2874         spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2875
2876         if (master->bus_lock_flag)
2877                 ret = -EBUSY;
2878         else
2879                 ret = __spi_async(spi, message);
2880
2881         spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2882
2883         return ret;
2884 }
2885 EXPORT_SYMBOL_GPL(spi_async);
2886
2887 /**
2888  * spi_async_locked - version of spi_async with exclusive bus usage
2889  * @spi: device with which data will be exchanged
2890  * @message: describes the data transfers, including completion callback
2891  * Context: any (irqs may be blocked, etc)
2892  *
2893  * This call may be used in_irq and other contexts which can't sleep,
2894  * as well as from task contexts which can sleep.
2895  *
2896  * The completion callback is invoked in a context which can't sleep.
2897  * Before that invocation, the value of message->status is undefined.
2898  * When the callback is issued, message->status holds either zero (to
2899  * indicate complete success) or a negative error code.  After that
2900  * callback returns, the driver which issued the transfer request may
2901  * deallocate the associated memory; it's no longer in use by any SPI
2902  * core or controller driver code.
2903  *
2904  * Note that although all messages to a spi_device are handled in
2905  * FIFO order, messages may go to different devices in other orders.
2906  * Some device might be higher priority, or have various "hard" access
2907  * time requirements, for example.
2908  *
2909  * On detection of any fault during the transfer, processing of
2910  * the entire message is aborted, and the device is deselected.
2911  * Until returning from the associated message completion callback,
2912  * no other spi_message queued to that device will be processed.
2913  * (This rule applies equally to all the synchronous transfer calls,
2914  * which are wrappers around this core asynchronous primitive.)
2915  *
2916  * Return: zero on success, else a negative error code.
2917  */
2918 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2919 {
2920         struct spi_master *master = spi->master;
2921         int ret;
2922         unsigned long flags;
2923
2924         ret = __spi_validate(spi, message);
2925         if (ret != 0)
2926                 return ret;
2927
2928         spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2929
2930         ret = __spi_async(spi, message);
2931
2932         spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2933
2934         return ret;
2935
2936 }
2937 EXPORT_SYMBOL_GPL(spi_async_locked);
2938
2939
2940 int spi_flash_read(struct spi_device *spi,
2941                    struct spi_flash_read_message *msg)
2942
2943 {
2944         struct spi_master *master = spi->master;
2945         struct device *rx_dev = NULL;
2946         int ret;
2947
2948         if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2949              msg->addr_nbits == SPI_NBITS_DUAL) &&
2950             !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2951                 return -EINVAL;
2952         if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2953              msg->addr_nbits == SPI_NBITS_QUAD) &&
2954             !(spi->mode & SPI_TX_QUAD))
2955                 return -EINVAL;
2956         if (msg->data_nbits == SPI_NBITS_DUAL &&
2957             !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2958                 return -EINVAL;
2959         if (msg->data_nbits == SPI_NBITS_QUAD &&
2960             !(spi->mode &  SPI_RX_QUAD))
2961                 return -EINVAL;
2962
2963         if (master->auto_runtime_pm) {
2964                 ret = pm_runtime_get_sync(master->dev.parent);
2965                 if (ret < 0) {
2966                         dev_err(&master->dev, "Failed to power device: %d\n",
2967                                 ret);
2968                         return ret;
2969                 }
2970         }
2971
2972         mutex_lock(&master->bus_lock_mutex);
2973         mutex_lock(&master->io_mutex);
2974         if (master->dma_rx && master->spi_flash_can_dma(spi, msg)) {
2975                 rx_dev = master->dma_rx->device->dev;
2976                 ret = spi_map_buf(master, rx_dev, &msg->rx_sg,
2977                                   msg->buf, msg->len,
2978                                   DMA_FROM_DEVICE);
2979                 if (!ret)
2980                         msg->cur_msg_mapped = true;
2981         }
2982         ret = master->spi_flash_read(spi, msg);
2983         if (msg->cur_msg_mapped)
2984                 spi_unmap_buf(master, rx_dev, &msg->rx_sg,
2985                               DMA_FROM_DEVICE);
2986         mutex_unlock(&master->io_mutex);
2987         mutex_unlock(&master->bus_lock_mutex);
2988
2989         if (master->auto_runtime_pm)
2990                 pm_runtime_put(master->dev.parent);
2991
2992         return ret;
2993 }
2994 EXPORT_SYMBOL_GPL(spi_flash_read);
2995
2996 /*-------------------------------------------------------------------------*/
2997
2998 /* Utility methods for SPI master protocol drivers, layered on
2999  * top of the core.  Some other utility methods are defined as
3000  * inline functions.
3001  */
3002
3003 static void spi_complete(void *arg)
3004 {
3005         complete(arg);
3006 }
3007
3008 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3009 {
3010         DECLARE_COMPLETION_ONSTACK(done);
3011         int status;
3012         struct spi_master *master = spi->master;
3013         unsigned long flags;
3014
3015         status = __spi_validate(spi, message);
3016         if (status != 0)
3017                 return status;
3018
3019         message->complete = spi_complete;
3020         message->context = &done;
3021         message->spi = spi;
3022
3023         SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
3024         SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3025
3026         /* If we're not using the legacy transfer method then we will
3027          * try to transfer in the calling context so special case.
3028          * This code would be less tricky if we could remove the
3029          * support for driver implemented message queues.
3030          */
3031         if (master->transfer == spi_queued_transfer) {
3032                 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
3033
3034                 trace_spi_message_submit(message);
3035
3036                 status = __spi_queued_transfer(spi, message, false);
3037
3038                 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
3039         } else {
3040                 status = spi_async_locked(spi, message);
3041         }
3042
3043         if (status == 0) {
3044                 /* Push out the messages in the calling context if we
3045                  * can.
3046                  */
3047                 if (master->transfer == spi_queued_transfer) {
3048                         SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
3049                                                        spi_sync_immediate);
3050                         SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3051                                                        spi_sync_immediate);
3052                         __spi_pump_messages(master, false);
3053                 }
3054
3055                 wait_for_completion(&done);
3056                 status = message->status;
3057         }
3058         message->context = NULL;
3059         return status;
3060 }
3061
3062 /**
3063  * spi_sync - blocking/synchronous SPI data transfers
3064  * @spi: device with which data will be exchanged
3065  * @message: describes the data transfers
3066  * Context: can sleep
3067  *
3068  * This call may only be used from a context that may sleep.  The sleep
3069  * is non-interruptible, and has no timeout.  Low-overhead controller
3070  * drivers may DMA directly into and out of the message buffers.
3071  *
3072  * Note that the SPI device's chip select is active during the message,
3073  * and then is normally disabled between messages.  Drivers for some
3074  * frequently-used devices may want to minimize costs of selecting a chip,
3075  * by leaving it selected in anticipation that the next message will go
3076  * to the same chip.  (That may increase power usage.)
3077  *
3078  * Also, the caller is guaranteeing that the memory associated with the
3079  * message will not be freed before this call returns.
3080  *
3081  * Return: zero on success, else a negative error code.
3082  */
3083 int spi_sync(struct spi_device *spi, struct spi_message *message)
3084 {
3085         int ret;
3086
3087         mutex_lock(&spi->master->bus_lock_mutex);
3088         ret = __spi_sync(spi, message);
3089         mutex_unlock(&spi->master->bus_lock_mutex);
3090
3091         return ret;
3092 }
3093 EXPORT_SYMBOL_GPL(spi_sync);
3094
3095 /**
3096  * spi_sync_locked - version of spi_sync with exclusive bus usage
3097  * @spi: device with which data will be exchanged
3098  * @message: describes the data transfers
3099  * Context: can sleep
3100  *
3101  * This call may only be used from a context that may sleep.  The sleep
3102  * is non-interruptible, and has no timeout.  Low-overhead controller
3103  * drivers may DMA directly into and out of the message buffers.
3104  *
3105  * This call should be used by drivers that require exclusive access to the
3106  * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3107  * be released by a spi_bus_unlock call when the exclusive access is over.
3108  *
3109  * Return: zero on success, else a negative error code.
3110  */
3111 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3112 {
3113         return __spi_sync(spi, message);
3114 }
3115 EXPORT_SYMBOL_GPL(spi_sync_locked);
3116
3117 /**
3118  * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3119  * @master: SPI bus master that should be locked for exclusive bus access
3120  * Context: can sleep
3121  *
3122  * This call may only be used from a context that may sleep.  The sleep
3123  * is non-interruptible, and has no timeout.
3124  *
3125  * This call should be used by drivers that require exclusive access to the
3126  * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3127  * exclusive access is over. Data transfer must be done by spi_sync_locked
3128  * and spi_async_locked calls when the SPI bus lock is held.
3129  *
3130  * Return: always zero.
3131  */
3132 int spi_bus_lock(struct spi_master *master)
3133 {
3134         unsigned long flags;
3135
3136         mutex_lock(&master->bus_lock_mutex);
3137
3138         spin_lock_irqsave(&master->bus_lock_spinlock, flags);
3139         master->bus_lock_flag = 1;
3140         spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
3141
3142         /* mutex remains locked until spi_bus_unlock is called */
3143
3144         return 0;
3145 }
3146 EXPORT_SYMBOL_GPL(spi_bus_lock);
3147
3148 /**
3149  * spi_bus_unlock - release the lock for exclusive SPI bus usage
3150  * @master: SPI bus master that was locked for exclusive bus access
3151  * Context: can sleep
3152  *
3153  * This call may only be used from a context that may sleep.  The sleep
3154  * is non-interruptible, and has no timeout.
3155  *
3156  * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3157  * call.
3158  *
3159  * Return: always zero.
3160  */
3161 int spi_bus_unlock(struct spi_master *master)
3162 {
3163         master->bus_lock_flag = 0;
3164
3165         mutex_unlock(&master->bus_lock_mutex);
3166
3167         return 0;
3168 }
3169 EXPORT_SYMBOL_GPL(spi_bus_unlock);
3170
3171 /* portable code must never pass more than 32 bytes */
3172 #define SPI_BUFSIZ      max(32, SMP_CACHE_BYTES)
3173
3174 static u8       *buf;
3175
3176 /**
3177  * spi_write_then_read - SPI synchronous write followed by read
3178  * @spi: device with which data will be exchanged
3179  * @txbuf: data to be written (need not be dma-safe)
3180  * @n_tx: size of txbuf, in bytes
3181  * @rxbuf: buffer into which data will be read (need not be dma-safe)
3182  * @n_rx: size of rxbuf, in bytes
3183  * Context: can sleep
3184  *
3185  * This performs a half duplex MicroWire style transaction with the
3186  * device, sending txbuf and then reading rxbuf.  The return value
3187  * is zero for success, else a negative errno status code.
3188  * This call may only be used from a context that may sleep.
3189  *
3190  * Parameters to this routine are always copied using a small buffer;
3191  * portable code should never use this for more than 32 bytes.
3192  * Performance-sensitive or bulk transfer code should instead use
3193  * spi_{async,sync}() calls with dma-safe buffers.
3194  *
3195  * Return: zero on success, else a negative error code.
3196  */
3197 int spi_write_then_read(struct spi_device *spi,
3198                 const void *txbuf, unsigned n_tx,
3199                 void *rxbuf, unsigned n_rx)
3200 {
3201         static DEFINE_MUTEX(lock);
3202
3203         int                     status;
3204         struct spi_message      message;
3205         struct spi_transfer     x[2];
3206         u8                      *local_buf;
3207
3208         /* Use preallocated DMA-safe buffer if we can.  We can't avoid
3209          * copying here, (as a pure convenience thing), but we can
3210          * keep heap costs out of the hot path unless someone else is
3211          * using the pre-allocated buffer or the transfer is too large.
3212          */
3213         if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
3214                 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3215                                     GFP_KERNEL | GFP_DMA);
3216                 if (!local_buf)
3217                         return -ENOMEM;
3218         } else {
3219                 local_buf = buf;
3220         }
3221
3222         spi_message_init(&message);
3223         memset(x, 0, sizeof(x));
3224         if (n_tx) {
3225                 x[0].len = n_tx;
3226                 spi_message_add_tail(&x[0], &message);
3227         }
3228         if (n_rx) {
3229                 x[1].len = n_rx;
3230                 spi_message_add_tail(&x[1], &message);
3231         }
3232
3233         memcpy(local_buf, txbuf, n_tx);
3234         x[0].tx_buf = local_buf;
3235         x[1].rx_buf = local_buf + n_tx;
3236
3237         /* do the i/o */
3238         status = spi_sync(spi, &message);
3239         if (status == 0)
3240                 memcpy(rxbuf, x[1].rx_buf, n_rx);
3241
3242         if (x[0].tx_buf == buf)
3243                 mutex_unlock(&lock);
3244         else
3245                 kfree(local_buf);
3246
3247         return status;
3248 }
3249 EXPORT_SYMBOL_GPL(spi_write_then_read);
3250
3251 /*-------------------------------------------------------------------------*/
3252
3253 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
3254 static int __spi_of_device_match(struct device *dev, void *data)
3255 {
3256         return dev->of_node == data;
3257 }
3258
3259 /* must call put_device() when done with returned spi_device device */
3260 static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3261 {
3262         struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3263                                                 __spi_of_device_match);
3264         return dev ? to_spi_device(dev) : NULL;
3265 }
3266
3267 static int __spi_of_master_match(struct device *dev, const void *data)
3268 {
3269         return dev->of_node == data;
3270 }
3271
3272 /* the spi masters are not using spi_bus, so we find it with another way */
3273 static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3274 {
3275         struct device *dev;
3276
3277         dev = class_find_device(&spi_master_class, NULL, node,
3278                                 __spi_of_master_match);
3279         if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3280                 dev = class_find_device(&spi_slave_class, NULL, node,
3281                                         __spi_of_master_match);
3282         if (!dev)
3283                 return NULL;
3284
3285         /* reference got in class_find_device */
3286         return container_of(dev, struct spi_master, dev);
3287 }
3288
3289 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3290                          void *arg)
3291 {
3292         struct of_reconfig_data *rd = arg;
3293         struct spi_master *master;
3294         struct spi_device *spi;
3295
3296         switch (of_reconfig_get_state_change(action, arg)) {
3297         case OF_RECONFIG_CHANGE_ADD:
3298                 master = of_find_spi_master_by_node(rd->dn->parent);
3299                 if (master == NULL)
3300                         return NOTIFY_OK;       /* not for us */
3301
3302                 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3303                         put_device(&master->dev);
3304                         return NOTIFY_OK;
3305                 }
3306
3307                 spi = of_register_spi_device(master, rd->dn);
3308                 put_device(&master->dev);
3309
3310                 if (IS_ERR(spi)) {
3311                         pr_err("%s: failed to create for '%s'\n",
3312                                         __func__, rd->dn->full_name);
3313                         of_node_clear_flag(rd->dn, OF_POPULATED);
3314                         return notifier_from_errno(PTR_ERR(spi));
3315                 }
3316                 break;
3317
3318         case OF_RECONFIG_CHANGE_REMOVE:
3319                 /* already depopulated? */
3320                 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3321                         return NOTIFY_OK;
3322
3323                 /* find our device by node */
3324                 spi = of_find_spi_device_by_node(rd->dn);
3325                 if (spi == NULL)
3326                         return NOTIFY_OK;       /* no? not meant for us */
3327
3328                 /* unregister takes one ref away */
3329                 spi_unregister_device(spi);
3330
3331                 /* and put the reference of the find */
3332                 put_device(&spi->dev);
3333                 break;
3334         }
3335
3336         return NOTIFY_OK;
3337 }
3338
3339 static struct notifier_block spi_of_notifier = {
3340         .notifier_call = of_spi_notify,
3341 };
3342 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3343 extern struct notifier_block spi_of_notifier;
3344 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3345
3346 #if IS_ENABLED(CONFIG_ACPI)
3347 static int spi_acpi_master_match(struct device *dev, const void *data)
3348 {
3349         return ACPI_COMPANION(dev->parent) == data;
3350 }
3351
3352 static int spi_acpi_device_match(struct device *dev, void *data)
3353 {
3354         return ACPI_COMPANION(dev) == data;
3355 }
3356
3357 static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device *adev)
3358 {
3359         struct device *dev;
3360
3361         dev = class_find_device(&spi_master_class, NULL, adev,
3362                                 spi_acpi_master_match);
3363         if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3364                 dev = class_find_device(&spi_slave_class, NULL, adev,
3365                                         spi_acpi_master_match);
3366         if (!dev)
3367                 return NULL;
3368
3369         return container_of(dev, struct spi_master, dev);
3370 }
3371
3372 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3373 {
3374         struct device *dev;
3375
3376         dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3377
3378         return dev ? to_spi_device(dev) : NULL;
3379 }
3380
3381 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3382                            void *arg)
3383 {
3384         struct acpi_device *adev = arg;
3385         struct spi_master *master;
3386         struct spi_device *spi;
3387
3388         switch (value) {
3389         case ACPI_RECONFIG_DEVICE_ADD:
3390                 master = acpi_spi_find_master_by_adev(adev->parent);
3391                 if (!master)
3392                         break;
3393
3394                 acpi_register_spi_device(master, adev);
3395                 put_device(&master->dev);
3396                 break;
3397         case ACPI_RECONFIG_DEVICE_REMOVE:
3398                 if (!acpi_device_enumerated(adev))
3399                         break;
3400
3401                 spi = acpi_spi_find_device_by_adev(adev);
3402                 if (!spi)
3403                         break;
3404
3405                 spi_unregister_device(spi);
3406                 put_device(&spi->dev);
3407                 break;
3408         }
3409
3410         return NOTIFY_OK;
3411 }
3412
3413 static struct notifier_block spi_acpi_notifier = {
3414         .notifier_call = acpi_spi_notify,
3415 };
3416 #else
3417 extern struct notifier_block spi_acpi_notifier;
3418 #endif
3419
3420 static int __init spi_init(void)
3421 {
3422         int     status;
3423
3424         buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
3425         if (!buf) {
3426                 status = -ENOMEM;
3427                 goto err0;
3428         }
3429
3430         status = bus_register(&spi_bus_type);
3431         if (status < 0)
3432                 goto err1;
3433
3434         status = class_register(&spi_master_class);
3435         if (status < 0)
3436                 goto err2;
3437
3438         if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
3439                 status = class_register(&spi_slave_class);
3440                 if (status < 0)
3441                         goto err3;
3442         }
3443
3444         if (IS_ENABLED(CONFIG_OF_DYNAMIC))
3445                 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3446         if (IS_ENABLED(CONFIG_ACPI))
3447                 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
3448
3449         return 0;
3450
3451 err3:
3452         class_unregister(&spi_master_class);
3453 err2:
3454         bus_unregister(&spi_bus_type);
3455 err1:
3456         kfree(buf);
3457         buf = NULL;
3458 err0:
3459         return status;
3460 }
3461
3462 /* board_info is normally registered in arch_initcall(),
3463  * but even essential drivers wait till later
3464  *
3465  * REVISIT only boardinfo really needs static linking. the rest (device and
3466  * driver registration) _could_ be dynamically linked (modular) ... costs
3467  * include needing to have boardinfo data structures be much more public.
3468  */
3469 postcore_initcall(spi_init);
3470