2c36c0ac708ab7d4e2b7d2123fbf00136bec6e5a
[sfrench/cifs-2.6.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 = S_IRUGO },                      \
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 = S_IRUGO },                      \
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         /* Device address */
1539         rc = of_property_read_u32(nc, "reg", &value);
1540         if (rc) {
1541                 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1542                         nc->full_name, rc);
1543                 return rc;
1544         }
1545         spi->chip_select = value;
1546
1547         /* Mode (clock phase/polarity/etc.) */
1548         if (of_find_property(nc, "spi-cpha", NULL))
1549                 spi->mode |= SPI_CPHA;
1550         if (of_find_property(nc, "spi-cpol", NULL))
1551                 spi->mode |= SPI_CPOL;
1552         if (of_find_property(nc, "spi-cs-high", NULL))
1553                 spi->mode |= SPI_CS_HIGH;
1554         if (of_find_property(nc, "spi-3wire", NULL))
1555                 spi->mode |= SPI_3WIRE;
1556         if (of_find_property(nc, "spi-lsb-first", NULL))
1557                 spi->mode |= SPI_LSB_FIRST;
1558
1559         /* Device DUAL/QUAD mode */
1560         if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1561                 switch (value) {
1562                 case 1:
1563                         break;
1564                 case 2:
1565                         spi->mode |= SPI_TX_DUAL;
1566                         break;
1567                 case 4:
1568                         spi->mode |= SPI_TX_QUAD;
1569                         break;
1570                 default:
1571                         dev_warn(&master->dev,
1572                                 "spi-tx-bus-width %d not supported\n",
1573                                 value);
1574                         break;
1575                 }
1576         }
1577
1578         if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1579                 switch (value) {
1580                 case 1:
1581                         break;
1582                 case 2:
1583                         spi->mode |= SPI_RX_DUAL;
1584                         break;
1585                 case 4:
1586                         spi->mode |= SPI_RX_QUAD;
1587                         break;
1588                 default:
1589                         dev_warn(&master->dev,
1590                                 "spi-rx-bus-width %d not supported\n",
1591                                 value);
1592                         break;
1593                 }
1594         }
1595
1596         /* Device speed */
1597         rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1598         if (rc) {
1599                 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1600                         nc->full_name, rc);
1601                 return rc;
1602         }
1603         spi->max_speed_hz = value;
1604
1605         return 0;
1606 }
1607
1608 static struct spi_device *
1609 of_register_spi_device(struct spi_master *master, struct device_node *nc)
1610 {
1611         struct spi_device *spi;
1612         int rc;
1613
1614         /* Alloc an spi_device */
1615         spi = spi_alloc_device(master);
1616         if (!spi) {
1617                 dev_err(&master->dev, "spi_device alloc error for %s\n",
1618                         nc->full_name);
1619                 rc = -ENOMEM;
1620                 goto err_out;
1621         }
1622
1623         /* Select device driver */
1624         rc = of_modalias_node(nc, spi->modalias,
1625                                 sizeof(spi->modalias));
1626         if (rc < 0) {
1627                 dev_err(&master->dev, "cannot find modalias for %s\n",
1628                         nc->full_name);
1629                 goto err_out;
1630         }
1631
1632         rc = of_spi_parse_dt(master, spi, nc);
1633         if (rc)
1634                 goto err_out;
1635
1636         /* Store a pointer to the node in the device structure */
1637         of_node_get(nc);
1638         spi->dev.of_node = nc;
1639
1640         /* Register the new device */
1641         rc = spi_add_device(spi);
1642         if (rc) {
1643                 dev_err(&master->dev, "spi_device register error %s\n",
1644                         nc->full_name);
1645                 goto err_of_node_put;
1646         }
1647
1648         return spi;
1649
1650 err_of_node_put:
1651         of_node_put(nc);
1652 err_out:
1653         spi_dev_put(spi);
1654         return ERR_PTR(rc);
1655 }
1656
1657 /**
1658  * of_register_spi_devices() - Register child devices onto the SPI bus
1659  * @master:     Pointer to spi_master device
1660  *
1661  * Registers an spi_device for each child node of master node which has a 'reg'
1662  * property.
1663  */
1664 static void of_register_spi_devices(struct spi_master *master)
1665 {
1666         struct spi_device *spi;
1667         struct device_node *nc;
1668
1669         if (!master->dev.of_node)
1670                 return;
1671
1672         for_each_available_child_of_node(master->dev.of_node, nc) {
1673                 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1674                         continue;
1675                 spi = of_register_spi_device(master, nc);
1676                 if (IS_ERR(spi)) {
1677                         dev_warn(&master->dev, "Failed to create SPI device for %s\n",
1678                                 nc->full_name);
1679                         of_node_clear_flag(nc, OF_POPULATED);
1680                 }
1681         }
1682 }
1683 #else
1684 static void of_register_spi_devices(struct spi_master *master) { }
1685 #endif
1686
1687 #ifdef CONFIG_ACPI
1688 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1689 {
1690         struct spi_device *spi = data;
1691         struct spi_master *master = spi->master;
1692
1693         if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1694                 struct acpi_resource_spi_serialbus *sb;
1695
1696                 sb = &ares->data.spi_serial_bus;
1697                 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1698                         /*
1699                          * ACPI DeviceSelection numbering is handled by the
1700                          * host controller driver in Windows and can vary
1701                          * from driver to driver. In Linux we always expect
1702                          * 0 .. max - 1 so we need to ask the driver to
1703                          * translate between the two schemes.
1704                          */
1705                         if (master->fw_translate_cs) {
1706                                 int cs = master->fw_translate_cs(master,
1707                                                 sb->device_selection);
1708                                 if (cs < 0)
1709                                         return cs;
1710                                 spi->chip_select = cs;
1711                         } else {
1712                                 spi->chip_select = sb->device_selection;
1713                         }
1714
1715                         spi->max_speed_hz = sb->connection_speed;
1716
1717                         if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1718                                 spi->mode |= SPI_CPHA;
1719                         if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1720                                 spi->mode |= SPI_CPOL;
1721                         if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1722                                 spi->mode |= SPI_CS_HIGH;
1723                 }
1724         } else if (spi->irq < 0) {
1725                 struct resource r;
1726
1727                 if (acpi_dev_resource_interrupt(ares, 0, &r))
1728                         spi->irq = r.start;
1729         }
1730
1731         /* Always tell the ACPI core to skip this resource */
1732         return 1;
1733 }
1734
1735 static acpi_status acpi_register_spi_device(struct spi_master *master,
1736                                             struct acpi_device *adev)
1737 {
1738         struct list_head resource_list;
1739         struct spi_device *spi;
1740         int ret;
1741
1742         if (acpi_bus_get_status(adev) || !adev->status.present ||
1743             acpi_device_enumerated(adev))
1744                 return AE_OK;
1745
1746         spi = spi_alloc_device(master);
1747         if (!spi) {
1748                 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1749                         dev_name(&adev->dev));
1750                 return AE_NO_MEMORY;
1751         }
1752
1753         ACPI_COMPANION_SET(&spi->dev, adev);
1754         spi->irq = -1;
1755
1756         INIT_LIST_HEAD(&resource_list);
1757         ret = acpi_dev_get_resources(adev, &resource_list,
1758                                      acpi_spi_add_resource, spi);
1759         acpi_dev_free_resource_list(&resource_list);
1760
1761         if (ret < 0 || !spi->max_speed_hz) {
1762                 spi_dev_put(spi);
1763                 return AE_OK;
1764         }
1765
1766         acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
1767                           sizeof(spi->modalias));
1768
1769         if (spi->irq < 0)
1770                 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1771
1772         acpi_device_set_enumerated(adev);
1773
1774         adev->power.flags.ignore_parent = true;
1775         if (spi_add_device(spi)) {
1776                 adev->power.flags.ignore_parent = false;
1777                 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1778                         dev_name(&adev->dev));
1779                 spi_dev_put(spi);
1780         }
1781
1782         return AE_OK;
1783 }
1784
1785 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1786                                        void *data, void **return_value)
1787 {
1788         struct spi_master *master = data;
1789         struct acpi_device *adev;
1790
1791         if (acpi_bus_get_device(handle, &adev))
1792                 return AE_OK;
1793
1794         return acpi_register_spi_device(master, adev);
1795 }
1796
1797 static void acpi_register_spi_devices(struct spi_master *master)
1798 {
1799         acpi_status status;
1800         acpi_handle handle;
1801
1802         handle = ACPI_HANDLE(master->dev.parent);
1803         if (!handle)
1804                 return;
1805
1806         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1807                                      acpi_spi_add_device, NULL,
1808                                      master, NULL);
1809         if (ACPI_FAILURE(status))
1810                 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1811 }
1812 #else
1813 static inline void acpi_register_spi_devices(struct spi_master *master) {}
1814 #endif /* CONFIG_ACPI */
1815
1816 static void spi_master_release(struct device *dev)
1817 {
1818         struct spi_master *master;
1819
1820         master = container_of(dev, struct spi_master, dev);
1821         kfree(master);
1822 }
1823
1824 static struct class spi_master_class = {
1825         .name           = "spi_master",
1826         .owner          = THIS_MODULE,
1827         .dev_release    = spi_master_release,
1828         .dev_groups     = spi_master_groups,
1829 };
1830
1831
1832 /**
1833  * spi_alloc_master - allocate SPI master controller
1834  * @dev: the controller, possibly using the platform_bus
1835  * @size: how much zeroed driver-private data to allocate; the pointer to this
1836  *      memory is in the driver_data field of the returned device,
1837  *      accessible with spi_master_get_devdata().
1838  * Context: can sleep
1839  *
1840  * This call is used only by SPI master controller drivers, which are the
1841  * only ones directly touching chip registers.  It's how they allocate
1842  * an spi_master structure, prior to calling spi_register_master().
1843  *
1844  * This must be called from context that can sleep.
1845  *
1846  * The caller is responsible for assigning the bus number and initializing
1847  * the master's methods before calling spi_register_master(); and (after errors
1848  * adding the device) calling spi_master_put() to prevent a memory leak.
1849  *
1850  * Return: the SPI master structure on success, else NULL.
1851  */
1852 struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
1853 {
1854         struct spi_master       *master;
1855
1856         if (!dev)
1857                 return NULL;
1858
1859         master = kzalloc(size + sizeof(*master), GFP_KERNEL);
1860         if (!master)
1861                 return NULL;
1862
1863         device_initialize(&master->dev);
1864         master->bus_num = -1;
1865         master->num_chipselect = 1;
1866         master->dev.class = &spi_master_class;
1867         master->dev.parent = dev;
1868         pm_suspend_ignore_children(&master->dev, true);
1869         spi_master_set_devdata(master, &master[1]);
1870
1871         return master;
1872 }
1873 EXPORT_SYMBOL_GPL(spi_alloc_master);
1874
1875 #ifdef CONFIG_OF
1876 static int of_spi_register_master(struct spi_master *master)
1877 {
1878         int nb, i, *cs;
1879         struct device_node *np = master->dev.of_node;
1880
1881         if (!np)
1882                 return 0;
1883
1884         nb = of_gpio_named_count(np, "cs-gpios");
1885         master->num_chipselect = max_t(int, nb, master->num_chipselect);
1886
1887         /* Return error only for an incorrectly formed cs-gpios property */
1888         if (nb == 0 || nb == -ENOENT)
1889                 return 0;
1890         else if (nb < 0)
1891                 return nb;
1892
1893         cs = devm_kzalloc(&master->dev,
1894                           sizeof(int) * master->num_chipselect,
1895                           GFP_KERNEL);
1896         master->cs_gpios = cs;
1897
1898         if (!master->cs_gpios)
1899                 return -ENOMEM;
1900
1901         for (i = 0; i < master->num_chipselect; i++)
1902                 cs[i] = -ENOENT;
1903
1904         for (i = 0; i < nb; i++)
1905                 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1906
1907         return 0;
1908 }
1909 #else
1910 static int of_spi_register_master(struct spi_master *master)
1911 {
1912         return 0;
1913 }
1914 #endif
1915
1916 /**
1917  * spi_register_master - register SPI master controller
1918  * @master: initialized master, originally from spi_alloc_master()
1919  * Context: can sleep
1920  *
1921  * SPI master controllers connect to their drivers using some non-SPI bus,
1922  * such as the platform bus.  The final stage of probe() in that code
1923  * includes calling spi_register_master() to hook up to this SPI bus glue.
1924  *
1925  * SPI controllers use board specific (often SOC specific) bus numbers,
1926  * and board-specific addressing for SPI devices combines those numbers
1927  * with chip select numbers.  Since SPI does not directly support dynamic
1928  * device identification, boards need configuration tables telling which
1929  * chip is at which address.
1930  *
1931  * This must be called from context that can sleep.  It returns zero on
1932  * success, else a negative error code (dropping the master's refcount).
1933  * After a successful return, the caller is responsible for calling
1934  * spi_unregister_master().
1935  *
1936  * Return: zero on success, else a negative error code.
1937  */
1938 int spi_register_master(struct spi_master *master)
1939 {
1940         static atomic_t         dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
1941         struct device           *dev = master->dev.parent;
1942         struct boardinfo        *bi;
1943         int                     status = -ENODEV;
1944         int                     dynamic = 0;
1945
1946         if (!dev)
1947                 return -ENODEV;
1948
1949         status = of_spi_register_master(master);
1950         if (status)
1951                 return status;
1952
1953         /* even if it's just one always-selected device, there must
1954          * be at least one chipselect
1955          */
1956         if (master->num_chipselect == 0)
1957                 return -EINVAL;
1958
1959         if ((master->bus_num < 0) && master->dev.of_node)
1960                 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1961
1962         /* convention:  dynamically assigned bus IDs count down from the max */
1963         if (master->bus_num < 0) {
1964                 /* FIXME switch to an IDR based scheme, something like
1965                  * I2C now uses, so we can't run out of "dynamic" IDs
1966                  */
1967                 master->bus_num = atomic_dec_return(&dyn_bus_id);
1968                 dynamic = 1;
1969         }
1970
1971         INIT_LIST_HEAD(&master->queue);
1972         spin_lock_init(&master->queue_lock);
1973         spin_lock_init(&master->bus_lock_spinlock);
1974         mutex_init(&master->bus_lock_mutex);
1975         mutex_init(&master->io_mutex);
1976         master->bus_lock_flag = 0;
1977         init_completion(&master->xfer_completion);
1978         if (!master->max_dma_len)
1979                 master->max_dma_len = INT_MAX;
1980
1981         /* register the device, then userspace will see it.
1982          * registration fails if the bus ID is in use.
1983          */
1984         dev_set_name(&master->dev, "spi%u", master->bus_num);
1985         status = device_add(&master->dev);
1986         if (status < 0)
1987                 goto done;
1988         dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
1989                         dynamic ? " (dynamic)" : "");
1990
1991         /* If we're using a queued driver, start the queue */
1992         if (master->transfer)
1993                 dev_info(dev, "master is unqueued, this is deprecated\n");
1994         else {
1995                 status = spi_master_initialize_queue(master);
1996                 if (status) {
1997                         device_del(&master->dev);
1998                         goto done;
1999                 }
2000         }
2001         /* add statistics */
2002         spin_lock_init(&master->statistics.lock);
2003
2004         mutex_lock(&board_lock);
2005         list_add_tail(&master->list, &spi_master_list);
2006         list_for_each_entry(bi, &board_list, list)
2007                 spi_match_master_to_boardinfo(master, &bi->board_info);
2008         mutex_unlock(&board_lock);
2009
2010         /* Register devices from the device tree and ACPI */
2011         of_register_spi_devices(master);
2012         acpi_register_spi_devices(master);
2013 done:
2014         return status;
2015 }
2016 EXPORT_SYMBOL_GPL(spi_register_master);
2017
2018 static void devm_spi_unregister(struct device *dev, void *res)
2019 {
2020         spi_unregister_master(*(struct spi_master **)res);
2021 }
2022
2023 /**
2024  * dev_spi_register_master - register managed SPI master controller
2025  * @dev:    device managing SPI master
2026  * @master: initialized master, originally from spi_alloc_master()
2027  * Context: can sleep
2028  *
2029  * Register a SPI device as with spi_register_master() which will
2030  * automatically be unregister
2031  *
2032  * Return: zero on success, else a negative error code.
2033  */
2034 int devm_spi_register_master(struct device *dev, struct spi_master *master)
2035 {
2036         struct spi_master **ptr;
2037         int ret;
2038
2039         ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2040         if (!ptr)
2041                 return -ENOMEM;
2042
2043         ret = spi_register_master(master);
2044         if (!ret) {
2045                 *ptr = master;
2046                 devres_add(dev, ptr);
2047         } else {
2048                 devres_free(ptr);
2049         }
2050
2051         return ret;
2052 }
2053 EXPORT_SYMBOL_GPL(devm_spi_register_master);
2054
2055 static int __unregister(struct device *dev, void *null)
2056 {
2057         spi_unregister_device(to_spi_device(dev));
2058         return 0;
2059 }
2060
2061 /**
2062  * spi_unregister_master - unregister SPI master controller
2063  * @master: the master being unregistered
2064  * Context: can sleep
2065  *
2066  * This call is used only by SPI master controller drivers, which are the
2067  * only ones directly touching chip registers.
2068  *
2069  * This must be called from context that can sleep.
2070  */
2071 void spi_unregister_master(struct spi_master *master)
2072 {
2073         int dummy;
2074
2075         if (master->queued) {
2076                 if (spi_destroy_queue(master))
2077                         dev_err(&master->dev, "queue remove failed\n");
2078         }
2079
2080         mutex_lock(&board_lock);
2081         list_del(&master->list);
2082         mutex_unlock(&board_lock);
2083
2084         dummy = device_for_each_child(&master->dev, NULL, __unregister);
2085         device_unregister(&master->dev);
2086 }
2087 EXPORT_SYMBOL_GPL(spi_unregister_master);
2088
2089 int spi_master_suspend(struct spi_master *master)
2090 {
2091         int ret;
2092
2093         /* Basically no-ops for non-queued masters */
2094         if (!master->queued)
2095                 return 0;
2096
2097         ret = spi_stop_queue(master);
2098         if (ret)
2099                 dev_err(&master->dev, "queue stop failed\n");
2100
2101         return ret;
2102 }
2103 EXPORT_SYMBOL_GPL(spi_master_suspend);
2104
2105 int spi_master_resume(struct spi_master *master)
2106 {
2107         int ret;
2108
2109         if (!master->queued)
2110                 return 0;
2111
2112         ret = spi_start_queue(master);
2113         if (ret)
2114                 dev_err(&master->dev, "queue restart failed\n");
2115
2116         return ret;
2117 }
2118 EXPORT_SYMBOL_GPL(spi_master_resume);
2119
2120 static int __spi_master_match(struct device *dev, const void *data)
2121 {
2122         struct spi_master *m;
2123         const u16 *bus_num = data;
2124
2125         m = container_of(dev, struct spi_master, dev);
2126         return m->bus_num == *bus_num;
2127 }
2128
2129 /**
2130  * spi_busnum_to_master - look up master associated with bus_num
2131  * @bus_num: the master's bus number
2132  * Context: can sleep
2133  *
2134  * This call may be used with devices that are registered after
2135  * arch init time.  It returns a refcounted pointer to the relevant
2136  * spi_master (which the caller must release), or NULL if there is
2137  * no such master registered.
2138  *
2139  * Return: the SPI master structure on success, else NULL.
2140  */
2141 struct spi_master *spi_busnum_to_master(u16 bus_num)
2142 {
2143         struct device           *dev;
2144         struct spi_master       *master = NULL;
2145
2146         dev = class_find_device(&spi_master_class, NULL, &bus_num,
2147                                 __spi_master_match);
2148         if (dev)
2149                 master = container_of(dev, struct spi_master, dev);
2150         /* reference got in class_find_device */
2151         return master;
2152 }
2153 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2154
2155 /*-------------------------------------------------------------------------*/
2156
2157 /* Core methods for SPI resource management */
2158
2159 /**
2160  * spi_res_alloc - allocate a spi resource that is life-cycle managed
2161  *                 during the processing of a spi_message while using
2162  *                 spi_transfer_one
2163  * @spi:     the spi device for which we allocate memory
2164  * @release: the release code to execute for this resource
2165  * @size:    size to alloc and return
2166  * @gfp:     GFP allocation flags
2167  *
2168  * Return: the pointer to the allocated data
2169  *
2170  * This may get enhanced in the future to allocate from a memory pool
2171  * of the @spi_device or @spi_master to avoid repeated allocations.
2172  */
2173 void *spi_res_alloc(struct spi_device *spi,
2174                     spi_res_release_t release,
2175                     size_t size, gfp_t gfp)
2176 {
2177         struct spi_res *sres;
2178
2179         sres = kzalloc(sizeof(*sres) + size, gfp);
2180         if (!sres)
2181                 return NULL;
2182
2183         INIT_LIST_HEAD(&sres->entry);
2184         sres->release = release;
2185
2186         return sres->data;
2187 }
2188 EXPORT_SYMBOL_GPL(spi_res_alloc);
2189
2190 /**
2191  * spi_res_free - free an spi resource
2192  * @res: pointer to the custom data of a resource
2193  *
2194  */
2195 void spi_res_free(void *res)
2196 {
2197         struct spi_res *sres = container_of(res, struct spi_res, data);
2198
2199         if (!res)
2200                 return;
2201
2202         WARN_ON(!list_empty(&sres->entry));
2203         kfree(sres);
2204 }
2205 EXPORT_SYMBOL_GPL(spi_res_free);
2206
2207 /**
2208  * spi_res_add - add a spi_res to the spi_message
2209  * @message: the spi message
2210  * @res:     the spi_resource
2211  */
2212 void spi_res_add(struct spi_message *message, void *res)
2213 {
2214         struct spi_res *sres = container_of(res, struct spi_res, data);
2215
2216         WARN_ON(!list_empty(&sres->entry));
2217         list_add_tail(&sres->entry, &message->resources);
2218 }
2219 EXPORT_SYMBOL_GPL(spi_res_add);
2220
2221 /**
2222  * spi_res_release - release all spi resources for this message
2223  * @master:  the @spi_master
2224  * @message: the @spi_message
2225  */
2226 void spi_res_release(struct spi_master *master,
2227                      struct spi_message *message)
2228 {
2229         struct spi_res *res;
2230
2231         while (!list_empty(&message->resources)) {
2232                 res = list_last_entry(&message->resources,
2233                                       struct spi_res, entry);
2234
2235                 if (res->release)
2236                         res->release(master, message, res->data);
2237
2238                 list_del(&res->entry);
2239
2240                 kfree(res);
2241         }
2242 }
2243 EXPORT_SYMBOL_GPL(spi_res_release);
2244
2245 /*-------------------------------------------------------------------------*/
2246
2247 /* Core methods for spi_message alterations */
2248
2249 static void __spi_replace_transfers_release(struct spi_master *master,
2250                                             struct spi_message *msg,
2251                                             void *res)
2252 {
2253         struct spi_replaced_transfers *rxfer = res;
2254         size_t i;
2255
2256         /* call extra callback if requested */
2257         if (rxfer->release)
2258                 rxfer->release(master, msg, res);
2259
2260         /* insert replaced transfers back into the message */
2261         list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2262
2263         /* remove the formerly inserted entries */
2264         for (i = 0; i < rxfer->inserted; i++)
2265                 list_del(&rxfer->inserted_transfers[i].transfer_list);
2266 }
2267
2268 /**
2269  * spi_replace_transfers - replace transfers with several transfers
2270  *                         and register change with spi_message.resources
2271  * @msg:           the spi_message we work upon
2272  * @xfer_first:    the first spi_transfer we want to replace
2273  * @remove:        number of transfers to remove
2274  * @insert:        the number of transfers we want to insert instead
2275  * @release:       extra release code necessary in some circumstances
2276  * @extradatasize: extra data to allocate (with alignment guarantees
2277  *                 of struct @spi_transfer)
2278  * @gfp:           gfp flags
2279  *
2280  * Returns: pointer to @spi_replaced_transfers,
2281  *          PTR_ERR(...) in case of errors.
2282  */
2283 struct spi_replaced_transfers *spi_replace_transfers(
2284         struct spi_message *msg,
2285         struct spi_transfer *xfer_first,
2286         size_t remove,
2287         size_t insert,
2288         spi_replaced_release_t release,
2289         size_t extradatasize,
2290         gfp_t gfp)
2291 {
2292         struct spi_replaced_transfers *rxfer;
2293         struct spi_transfer *xfer;
2294         size_t i;
2295
2296         /* allocate the structure using spi_res */
2297         rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2298                               insert * sizeof(struct spi_transfer)
2299                               + sizeof(struct spi_replaced_transfers)
2300                               + extradatasize,
2301                               gfp);
2302         if (!rxfer)
2303                 return ERR_PTR(-ENOMEM);
2304
2305         /* the release code to invoke before running the generic release */
2306         rxfer->release = release;
2307
2308         /* assign extradata */
2309         if (extradatasize)
2310                 rxfer->extradata =
2311                         &rxfer->inserted_transfers[insert];
2312
2313         /* init the replaced_transfers list */
2314         INIT_LIST_HEAD(&rxfer->replaced_transfers);
2315
2316         /* assign the list_entry after which we should reinsert
2317          * the @replaced_transfers - it may be spi_message.messages!
2318          */
2319         rxfer->replaced_after = xfer_first->transfer_list.prev;
2320
2321         /* remove the requested number of transfers */
2322         for (i = 0; i < remove; i++) {
2323                 /* if the entry after replaced_after it is msg->transfers
2324                  * then we have been requested to remove more transfers
2325                  * than are in the list
2326                  */
2327                 if (rxfer->replaced_after->next == &msg->transfers) {
2328                         dev_err(&msg->spi->dev,
2329                                 "requested to remove more spi_transfers than are available\n");
2330                         /* insert replaced transfers back into the message */
2331                         list_splice(&rxfer->replaced_transfers,
2332                                     rxfer->replaced_after);
2333
2334                         /* free the spi_replace_transfer structure */
2335                         spi_res_free(rxfer);
2336
2337                         /* and return with an error */
2338                         return ERR_PTR(-EINVAL);
2339                 }
2340
2341                 /* remove the entry after replaced_after from list of
2342                  * transfers and add it to list of replaced_transfers
2343                  */
2344                 list_move_tail(rxfer->replaced_after->next,
2345                                &rxfer->replaced_transfers);
2346         }
2347
2348         /* create copy of the given xfer with identical settings
2349          * based on the first transfer to get removed
2350          */
2351         for (i = 0; i < insert; i++) {
2352                 /* we need to run in reverse order */
2353                 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2354
2355                 /* copy all spi_transfer data */
2356                 memcpy(xfer, xfer_first, sizeof(*xfer));
2357
2358                 /* add to list */
2359                 list_add(&xfer->transfer_list, rxfer->replaced_after);
2360
2361                 /* clear cs_change and delay_usecs for all but the last */
2362                 if (i) {
2363                         xfer->cs_change = false;
2364                         xfer->delay_usecs = 0;
2365                 }
2366         }
2367
2368         /* set up inserted */
2369         rxfer->inserted = insert;
2370
2371         /* and register it with spi_res/spi_message */
2372         spi_res_add(msg, rxfer);
2373
2374         return rxfer;
2375 }
2376 EXPORT_SYMBOL_GPL(spi_replace_transfers);
2377
2378 static int __spi_split_transfer_maxsize(struct spi_master *master,
2379                                         struct spi_message *msg,
2380                                         struct spi_transfer **xferp,
2381                                         size_t maxsize,
2382                                         gfp_t gfp)
2383 {
2384         struct spi_transfer *xfer = *xferp, *xfers;
2385         struct spi_replaced_transfers *srt;
2386         size_t offset;
2387         size_t count, i;
2388
2389         /* warn once about this fact that we are splitting a transfer */
2390         dev_warn_once(&msg->spi->dev,
2391                       "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2392                       xfer->len, maxsize);
2393
2394         /* calculate how many we have to replace */
2395         count = DIV_ROUND_UP(xfer->len, maxsize);
2396
2397         /* create replacement */
2398         srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
2399         if (IS_ERR(srt))
2400                 return PTR_ERR(srt);
2401         xfers = srt->inserted_transfers;
2402
2403         /* now handle each of those newly inserted spi_transfers
2404          * note that the replacements spi_transfers all are preset
2405          * to the same values as *xferp, so tx_buf, rx_buf and len
2406          * are all identical (as well as most others)
2407          * so we just have to fix up len and the pointers.
2408          *
2409          * this also includes support for the depreciated
2410          * spi_message.is_dma_mapped interface
2411          */
2412
2413         /* the first transfer just needs the length modified, so we
2414          * run it outside the loop
2415          */
2416         xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
2417
2418         /* all the others need rx_buf/tx_buf also set */
2419         for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2420                 /* update rx_buf, tx_buf and dma */
2421                 if (xfers[i].rx_buf)
2422                         xfers[i].rx_buf += offset;
2423                 if (xfers[i].rx_dma)
2424                         xfers[i].rx_dma += offset;
2425                 if (xfers[i].tx_buf)
2426                         xfers[i].tx_buf += offset;
2427                 if (xfers[i].tx_dma)
2428                         xfers[i].tx_dma += offset;
2429
2430                 /* update length */
2431                 xfers[i].len = min(maxsize, xfers[i].len - offset);
2432         }
2433
2434         /* we set up xferp to the last entry we have inserted,
2435          * so that we skip those already split transfers
2436          */
2437         *xferp = &xfers[count - 1];
2438
2439         /* increment statistics counters */
2440         SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2441                                        transfers_split_maxsize);
2442         SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2443                                        transfers_split_maxsize);
2444
2445         return 0;
2446 }
2447
2448 /**
2449  * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2450  *                              when an individual transfer exceeds a
2451  *                              certain size
2452  * @master:    the @spi_master for this transfer
2453  * @msg:   the @spi_message to transform
2454  * @maxsize:  the maximum when to apply this
2455  * @gfp: GFP allocation flags
2456  *
2457  * Return: status of transformation
2458  */
2459 int spi_split_transfers_maxsize(struct spi_master *master,
2460                                 struct spi_message *msg,
2461                                 size_t maxsize,
2462                                 gfp_t gfp)
2463 {
2464         struct spi_transfer *xfer;
2465         int ret;
2466
2467         /* iterate over the transfer_list,
2468          * but note that xfer is advanced to the last transfer inserted
2469          * to avoid checking sizes again unnecessarily (also xfer does
2470          * potentiall belong to a different list by the time the
2471          * replacement has happened
2472          */
2473         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2474                 if (xfer->len > maxsize) {
2475                         ret = __spi_split_transfer_maxsize(
2476                                 master, msg, &xfer, maxsize, gfp);
2477                         if (ret)
2478                                 return ret;
2479                 }
2480         }
2481
2482         return 0;
2483 }
2484 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2485
2486 /*-------------------------------------------------------------------------*/
2487
2488 /* Core methods for SPI master protocol drivers.  Some of the
2489  * other core methods are currently defined as inline functions.
2490  */
2491
2492 static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2493 {
2494         if (master->bits_per_word_mask) {
2495                 /* Only 32 bits fit in the mask */
2496                 if (bits_per_word > 32)
2497                         return -EINVAL;
2498                 if (!(master->bits_per_word_mask &
2499                                 SPI_BPW_MASK(bits_per_word)))
2500                         return -EINVAL;
2501         }
2502
2503         return 0;
2504 }
2505
2506 /**
2507  * spi_setup - setup SPI mode and clock rate
2508  * @spi: the device whose settings are being modified
2509  * Context: can sleep, and no requests are queued to the device
2510  *
2511  * SPI protocol drivers may need to update the transfer mode if the
2512  * device doesn't work with its default.  They may likewise need
2513  * to update clock rates or word sizes from initial values.  This function
2514  * changes those settings, and must be called from a context that can sleep.
2515  * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2516  * effect the next time the device is selected and data is transferred to
2517  * or from it.  When this function returns, the spi device is deselected.
2518  *
2519  * Note that this call will fail if the protocol driver specifies an option
2520  * that the underlying controller or its driver does not support.  For
2521  * example, not all hardware supports wire transfers using nine bit words,
2522  * LSB-first wire encoding, or active-high chipselects.
2523  *
2524  * Return: zero on success, else a negative error code.
2525  */
2526 int spi_setup(struct spi_device *spi)
2527 {
2528         unsigned        bad_bits, ugly_bits;
2529         int             status;
2530
2531         /* check mode to prevent that DUAL and QUAD set at the same time
2532          */
2533         if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2534                 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2535                 dev_err(&spi->dev,
2536                 "setup: can not select dual and quad at the same time\n");
2537                 return -EINVAL;
2538         }
2539         /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2540          */
2541         if ((spi->mode & SPI_3WIRE) && (spi->mode &
2542                 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2543                 return -EINVAL;
2544         /* help drivers fail *cleanly* when they need options
2545          * that aren't supported with their current master
2546          */
2547         bad_bits = spi->mode & ~spi->master->mode_bits;
2548         ugly_bits = bad_bits &
2549                     (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2550         if (ugly_bits) {
2551                 dev_warn(&spi->dev,
2552                          "setup: ignoring unsupported mode bits %x\n",
2553                          ugly_bits);
2554                 spi->mode &= ~ugly_bits;
2555                 bad_bits &= ~ugly_bits;
2556         }
2557         if (bad_bits) {
2558                 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
2559                         bad_bits);
2560                 return -EINVAL;
2561         }
2562
2563         if (!spi->bits_per_word)
2564                 spi->bits_per_word = 8;
2565
2566         status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2567         if (status)
2568                 return status;
2569
2570         if (!spi->max_speed_hz)
2571                 spi->max_speed_hz = spi->master->max_speed_hz;
2572
2573         if (spi->master->setup)
2574                 status = spi->master->setup(spi);
2575
2576         spi_set_cs(spi, false);
2577
2578         dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2579                         (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2580                         (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2581                         (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2582                         (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2583                         (spi->mode & SPI_LOOP) ? "loopback, " : "",
2584                         spi->bits_per_word, spi->max_speed_hz,
2585                         status);
2586
2587         return status;
2588 }
2589 EXPORT_SYMBOL_GPL(spi_setup);
2590
2591 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
2592 {
2593         struct spi_master *master = spi->master;
2594         struct spi_transfer *xfer;
2595         int w_size;
2596
2597         if (list_empty(&message->transfers))
2598                 return -EINVAL;
2599
2600         /* Half-duplex links include original MicroWire, and ones with
2601          * only one data pin like SPI_3WIRE (switches direction) or where
2602          * either MOSI or MISO is missing.  They can also be caused by
2603          * software limitations.
2604          */
2605         if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2606                         || (spi->mode & SPI_3WIRE)) {
2607                 unsigned flags = master->flags;
2608
2609                 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2610                         if (xfer->rx_buf && xfer->tx_buf)
2611                                 return -EINVAL;
2612                         if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2613                                 return -EINVAL;
2614                         if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2615                                 return -EINVAL;
2616                 }
2617         }
2618
2619         /**
2620          * Set transfer bits_per_word and max speed as spi device default if
2621          * it is not set for this transfer.
2622          * Set transfer tx_nbits and rx_nbits as single transfer default
2623          * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2624          */
2625         message->frame_length = 0;
2626         list_for_each_entry(xfer, &message->transfers, transfer_list) {
2627                 message->frame_length += xfer->len;
2628                 if (!xfer->bits_per_word)
2629                         xfer->bits_per_word = spi->bits_per_word;
2630
2631                 if (!xfer->speed_hz)
2632                         xfer->speed_hz = spi->max_speed_hz;
2633                 if (!xfer->speed_hz)
2634                         xfer->speed_hz = master->max_speed_hz;
2635
2636                 if (master->max_speed_hz &&
2637                     xfer->speed_hz > master->max_speed_hz)
2638                         xfer->speed_hz = master->max_speed_hz;
2639
2640                 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2641                         return -EINVAL;
2642
2643                 /*
2644                  * SPI transfer length should be multiple of SPI word size
2645                  * where SPI word size should be power-of-two multiple
2646                  */
2647                 if (xfer->bits_per_word <= 8)
2648                         w_size = 1;
2649                 else if (xfer->bits_per_word <= 16)
2650                         w_size = 2;
2651                 else
2652                         w_size = 4;
2653
2654                 /* No partial transfers accepted */
2655                 if (xfer->len % w_size)
2656                         return -EINVAL;
2657
2658                 if (xfer->speed_hz && master->min_speed_hz &&
2659                     xfer->speed_hz < master->min_speed_hz)
2660                         return -EINVAL;
2661
2662                 if (xfer->tx_buf && !xfer->tx_nbits)
2663                         xfer->tx_nbits = SPI_NBITS_SINGLE;
2664                 if (xfer->rx_buf && !xfer->rx_nbits)
2665                         xfer->rx_nbits = SPI_NBITS_SINGLE;
2666                 /* check transfer tx/rx_nbits:
2667                  * 1. check the value matches one of single, dual and quad
2668                  * 2. check tx/rx_nbits match the mode in spi_device
2669                  */
2670                 if (xfer->tx_buf) {
2671                         if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2672                                 xfer->tx_nbits != SPI_NBITS_DUAL &&
2673                                 xfer->tx_nbits != SPI_NBITS_QUAD)
2674                                 return -EINVAL;
2675                         if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2676                                 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2677                                 return -EINVAL;
2678                         if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2679                                 !(spi->mode & SPI_TX_QUAD))
2680                                 return -EINVAL;
2681                 }
2682                 /* check transfer rx_nbits */
2683                 if (xfer->rx_buf) {
2684                         if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2685                                 xfer->rx_nbits != SPI_NBITS_DUAL &&
2686                                 xfer->rx_nbits != SPI_NBITS_QUAD)
2687                                 return -EINVAL;
2688                         if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2689                                 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2690                                 return -EINVAL;
2691                         if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2692                                 !(spi->mode & SPI_RX_QUAD))
2693                                 return -EINVAL;
2694                 }
2695         }
2696
2697         message->status = -EINPROGRESS;
2698
2699         return 0;
2700 }
2701
2702 static int __spi_async(struct spi_device *spi, struct spi_message *message)
2703 {
2704         struct spi_master *master = spi->master;
2705
2706         message->spi = spi;
2707
2708         SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2709         SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2710
2711         trace_spi_message_submit(message);
2712
2713         return master->transfer(spi, message);
2714 }
2715
2716 /**
2717  * spi_async - asynchronous SPI transfer
2718  * @spi: device with which data will be exchanged
2719  * @message: describes the data transfers, including completion callback
2720  * Context: any (irqs may be blocked, etc)
2721  *
2722  * This call may be used in_irq and other contexts which can't sleep,
2723  * as well as from task contexts which can sleep.
2724  *
2725  * The completion callback is invoked in a context which can't sleep.
2726  * Before that invocation, the value of message->status is undefined.
2727  * When the callback is issued, message->status holds either zero (to
2728  * indicate complete success) or a negative error code.  After that
2729  * callback returns, the driver which issued the transfer request may
2730  * deallocate the associated memory; it's no longer in use by any SPI
2731  * core or controller driver code.
2732  *
2733  * Note that although all messages to a spi_device are handled in
2734  * FIFO order, messages may go to different devices in other orders.
2735  * Some device might be higher priority, or have various "hard" access
2736  * time requirements, for example.
2737  *
2738  * On detection of any fault during the transfer, processing of
2739  * the entire message is aborted, and the device is deselected.
2740  * Until returning from the associated message completion callback,
2741  * no other spi_message queued to that device will be processed.
2742  * (This rule applies equally to all the synchronous transfer calls,
2743  * which are wrappers around this core asynchronous primitive.)
2744  *
2745  * Return: zero on success, else a negative error code.
2746  */
2747 int spi_async(struct spi_device *spi, struct spi_message *message)
2748 {
2749         struct spi_master *master = spi->master;
2750         int ret;
2751         unsigned long flags;
2752
2753         ret = __spi_validate(spi, message);
2754         if (ret != 0)
2755                 return ret;
2756
2757         spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2758
2759         if (master->bus_lock_flag)
2760                 ret = -EBUSY;
2761         else
2762                 ret = __spi_async(spi, message);
2763
2764         spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2765
2766         return ret;
2767 }
2768 EXPORT_SYMBOL_GPL(spi_async);
2769
2770 /**
2771  * spi_async_locked - version of spi_async with exclusive bus usage
2772  * @spi: device with which data will be exchanged
2773  * @message: describes the data transfers, including completion callback
2774  * Context: any (irqs may be blocked, etc)
2775  *
2776  * This call may be used in_irq and other contexts which can't sleep,
2777  * as well as from task contexts which can sleep.
2778  *
2779  * The completion callback is invoked in a context which can't sleep.
2780  * Before that invocation, the value of message->status is undefined.
2781  * When the callback is issued, message->status holds either zero (to
2782  * indicate complete success) or a negative error code.  After that
2783  * callback returns, the driver which issued the transfer request may
2784  * deallocate the associated memory; it's no longer in use by any SPI
2785  * core or controller driver code.
2786  *
2787  * Note that although all messages to a spi_device are handled in
2788  * FIFO order, messages may go to different devices in other orders.
2789  * Some device might be higher priority, or have various "hard" access
2790  * time requirements, for example.
2791  *
2792  * On detection of any fault during the transfer, processing of
2793  * the entire message is aborted, and the device is deselected.
2794  * Until returning from the associated message completion callback,
2795  * no other spi_message queued to that device will be processed.
2796  * (This rule applies equally to all the synchronous transfer calls,
2797  * which are wrappers around this core asynchronous primitive.)
2798  *
2799  * Return: zero on success, else a negative error code.
2800  */
2801 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2802 {
2803         struct spi_master *master = spi->master;
2804         int ret;
2805         unsigned long flags;
2806
2807         ret = __spi_validate(spi, message);
2808         if (ret != 0)
2809                 return ret;
2810
2811         spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2812
2813         ret = __spi_async(spi, message);
2814
2815         spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2816
2817         return ret;
2818
2819 }
2820 EXPORT_SYMBOL_GPL(spi_async_locked);
2821
2822
2823 int spi_flash_read(struct spi_device *spi,
2824                    struct spi_flash_read_message *msg)
2825
2826 {
2827         struct spi_master *master = spi->master;
2828         struct device *rx_dev = NULL;
2829         int ret;
2830
2831         if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2832              msg->addr_nbits == SPI_NBITS_DUAL) &&
2833             !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2834                 return -EINVAL;
2835         if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2836              msg->addr_nbits == SPI_NBITS_QUAD) &&
2837             !(spi->mode & SPI_TX_QUAD))
2838                 return -EINVAL;
2839         if (msg->data_nbits == SPI_NBITS_DUAL &&
2840             !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2841                 return -EINVAL;
2842         if (msg->data_nbits == SPI_NBITS_QUAD &&
2843             !(spi->mode &  SPI_RX_QUAD))
2844                 return -EINVAL;
2845
2846         if (master->auto_runtime_pm) {
2847                 ret = pm_runtime_get_sync(master->dev.parent);
2848                 if (ret < 0) {
2849                         dev_err(&master->dev, "Failed to power device: %d\n",
2850                                 ret);
2851                         return ret;
2852                 }
2853         }
2854
2855         mutex_lock(&master->bus_lock_mutex);
2856         mutex_lock(&master->io_mutex);
2857         if (master->dma_rx) {
2858                 rx_dev = master->dma_rx->device->dev;
2859                 ret = spi_map_buf(master, rx_dev, &msg->rx_sg,
2860                                   msg->buf, msg->len,
2861                                   DMA_FROM_DEVICE);
2862                 if (!ret)
2863                         msg->cur_msg_mapped = true;
2864         }
2865         ret = master->spi_flash_read(spi, msg);
2866         if (msg->cur_msg_mapped)
2867                 spi_unmap_buf(master, rx_dev, &msg->rx_sg,
2868                               DMA_FROM_DEVICE);
2869         mutex_unlock(&master->io_mutex);
2870         mutex_unlock(&master->bus_lock_mutex);
2871
2872         if (master->auto_runtime_pm)
2873                 pm_runtime_put(master->dev.parent);
2874
2875         return ret;
2876 }
2877 EXPORT_SYMBOL_GPL(spi_flash_read);
2878
2879 /*-------------------------------------------------------------------------*/
2880
2881 /* Utility methods for SPI master protocol drivers, layered on
2882  * top of the core.  Some other utility methods are defined as
2883  * inline functions.
2884  */
2885
2886 static void spi_complete(void *arg)
2887 {
2888         complete(arg);
2889 }
2890
2891 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
2892 {
2893         DECLARE_COMPLETION_ONSTACK(done);
2894         int status;
2895         struct spi_master *master = spi->master;
2896         unsigned long flags;
2897
2898         status = __spi_validate(spi, message);
2899         if (status != 0)
2900                 return status;
2901
2902         message->complete = spi_complete;
2903         message->context = &done;
2904         message->spi = spi;
2905
2906         SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2907         SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2908
2909         /* If we're not using the legacy transfer method then we will
2910          * try to transfer in the calling context so special case.
2911          * This code would be less tricky if we could remove the
2912          * support for driver implemented message queues.
2913          */
2914         if (master->transfer == spi_queued_transfer) {
2915                 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2916
2917                 trace_spi_message_submit(message);
2918
2919                 status = __spi_queued_transfer(spi, message, false);
2920
2921                 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2922         } else {
2923                 status = spi_async_locked(spi, message);
2924         }
2925
2926         if (status == 0) {
2927                 /* Push out the messages in the calling context if we
2928                  * can.
2929                  */
2930                 if (master->transfer == spi_queued_transfer) {
2931                         SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2932                                                        spi_sync_immediate);
2933                         SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
2934                                                        spi_sync_immediate);
2935                         __spi_pump_messages(master, false);
2936                 }
2937
2938                 wait_for_completion(&done);
2939                 status = message->status;
2940         }
2941         message->context = NULL;
2942         return status;
2943 }
2944
2945 /**
2946  * spi_sync - blocking/synchronous SPI data transfers
2947  * @spi: device with which data will be exchanged
2948  * @message: describes the data transfers
2949  * Context: can sleep
2950  *
2951  * This call may only be used from a context that may sleep.  The sleep
2952  * is non-interruptible, and has no timeout.  Low-overhead controller
2953  * drivers may DMA directly into and out of the message buffers.
2954  *
2955  * Note that the SPI device's chip select is active during the message,
2956  * and then is normally disabled between messages.  Drivers for some
2957  * frequently-used devices may want to minimize costs of selecting a chip,
2958  * by leaving it selected in anticipation that the next message will go
2959  * to the same chip.  (That may increase power usage.)
2960  *
2961  * Also, the caller is guaranteeing that the memory associated with the
2962  * message will not be freed before this call returns.
2963  *
2964  * Return: zero on success, else a negative error code.
2965  */
2966 int spi_sync(struct spi_device *spi, struct spi_message *message)
2967 {
2968         int ret;
2969
2970         mutex_lock(&spi->master->bus_lock_mutex);
2971         ret = __spi_sync(spi, message);
2972         mutex_unlock(&spi->master->bus_lock_mutex);
2973
2974         return ret;
2975 }
2976 EXPORT_SYMBOL_GPL(spi_sync);
2977
2978 /**
2979  * spi_sync_locked - version of spi_sync with exclusive bus usage
2980  * @spi: device with which data will be exchanged
2981  * @message: describes the data transfers
2982  * Context: can sleep
2983  *
2984  * This call may only be used from a context that may sleep.  The sleep
2985  * is non-interruptible, and has no timeout.  Low-overhead controller
2986  * drivers may DMA directly into and out of the message buffers.
2987  *
2988  * This call should be used by drivers that require exclusive access to the
2989  * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
2990  * be released by a spi_bus_unlock call when the exclusive access is over.
2991  *
2992  * Return: zero on success, else a negative error code.
2993  */
2994 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2995 {
2996         return __spi_sync(spi, message);
2997 }
2998 EXPORT_SYMBOL_GPL(spi_sync_locked);
2999
3000 /**
3001  * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3002  * @master: SPI bus master that should be locked for exclusive bus access
3003  * Context: can sleep
3004  *
3005  * This call may only be used from a context that may sleep.  The sleep
3006  * is non-interruptible, and has no timeout.
3007  *
3008  * This call should be used by drivers that require exclusive access to the
3009  * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3010  * exclusive access is over. Data transfer must be done by spi_sync_locked
3011  * and spi_async_locked calls when the SPI bus lock is held.
3012  *
3013  * Return: always zero.
3014  */
3015 int spi_bus_lock(struct spi_master *master)
3016 {
3017         unsigned long flags;
3018
3019         mutex_lock(&master->bus_lock_mutex);
3020
3021         spin_lock_irqsave(&master->bus_lock_spinlock, flags);
3022         master->bus_lock_flag = 1;
3023         spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
3024
3025         /* mutex remains locked until spi_bus_unlock is called */
3026
3027         return 0;
3028 }
3029 EXPORT_SYMBOL_GPL(spi_bus_lock);
3030
3031 /**
3032  * spi_bus_unlock - release the lock for exclusive SPI bus usage
3033  * @master: SPI bus master that was locked for exclusive bus access
3034  * Context: can sleep
3035  *
3036  * This call may only be used from a context that may sleep.  The sleep
3037  * is non-interruptible, and has no timeout.
3038  *
3039  * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3040  * call.
3041  *
3042  * Return: always zero.
3043  */
3044 int spi_bus_unlock(struct spi_master *master)
3045 {
3046         master->bus_lock_flag = 0;
3047
3048         mutex_unlock(&master->bus_lock_mutex);
3049
3050         return 0;
3051 }
3052 EXPORT_SYMBOL_GPL(spi_bus_unlock);
3053
3054 /* portable code must never pass more than 32 bytes */
3055 #define SPI_BUFSIZ      max(32, SMP_CACHE_BYTES)
3056
3057 static u8       *buf;
3058
3059 /**
3060  * spi_write_then_read - SPI synchronous write followed by read
3061  * @spi: device with which data will be exchanged
3062  * @txbuf: data to be written (need not be dma-safe)
3063  * @n_tx: size of txbuf, in bytes
3064  * @rxbuf: buffer into which data will be read (need not be dma-safe)
3065  * @n_rx: size of rxbuf, in bytes
3066  * Context: can sleep
3067  *
3068  * This performs a half duplex MicroWire style transaction with the
3069  * device, sending txbuf and then reading rxbuf.  The return value
3070  * is zero for success, else a negative errno status code.
3071  * This call may only be used from a context that may sleep.
3072  *
3073  * Parameters to this routine are always copied using a small buffer;
3074  * portable code should never use this for more than 32 bytes.
3075  * Performance-sensitive or bulk transfer code should instead use
3076  * spi_{async,sync}() calls with dma-safe buffers.
3077  *
3078  * Return: zero on success, else a negative error code.
3079  */
3080 int spi_write_then_read(struct spi_device *spi,
3081                 const void *txbuf, unsigned n_tx,
3082                 void *rxbuf, unsigned n_rx)
3083 {
3084         static DEFINE_MUTEX(lock);
3085
3086         int                     status;
3087         struct spi_message      message;
3088         struct spi_transfer     x[2];
3089         u8                      *local_buf;
3090
3091         /* Use preallocated DMA-safe buffer if we can.  We can't avoid
3092          * copying here, (as a pure convenience thing), but we can
3093          * keep heap costs out of the hot path unless someone else is
3094          * using the pre-allocated buffer or the transfer is too large.
3095          */
3096         if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
3097                 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3098                                     GFP_KERNEL | GFP_DMA);
3099                 if (!local_buf)
3100                         return -ENOMEM;
3101         } else {
3102                 local_buf = buf;
3103         }
3104
3105         spi_message_init(&message);
3106         memset(x, 0, sizeof(x));
3107         if (n_tx) {
3108                 x[0].len = n_tx;
3109                 spi_message_add_tail(&x[0], &message);
3110         }
3111         if (n_rx) {
3112                 x[1].len = n_rx;
3113                 spi_message_add_tail(&x[1], &message);
3114         }
3115
3116         memcpy(local_buf, txbuf, n_tx);
3117         x[0].tx_buf = local_buf;
3118         x[1].rx_buf = local_buf + n_tx;
3119
3120         /* do the i/o */
3121         status = spi_sync(spi, &message);
3122         if (status == 0)
3123                 memcpy(rxbuf, x[1].rx_buf, n_rx);
3124
3125         if (x[0].tx_buf == buf)
3126                 mutex_unlock(&lock);
3127         else
3128                 kfree(local_buf);
3129
3130         return status;
3131 }
3132 EXPORT_SYMBOL_GPL(spi_write_then_read);
3133
3134 /*-------------------------------------------------------------------------*/
3135
3136 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
3137 static int __spi_of_device_match(struct device *dev, void *data)
3138 {
3139         return dev->of_node == data;
3140 }
3141
3142 /* must call put_device() when done with returned spi_device device */
3143 static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3144 {
3145         struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3146                                                 __spi_of_device_match);
3147         return dev ? to_spi_device(dev) : NULL;
3148 }
3149
3150 static int __spi_of_master_match(struct device *dev, const void *data)
3151 {
3152         return dev->of_node == data;
3153 }
3154
3155 /* the spi masters are not using spi_bus, so we find it with another way */
3156 static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3157 {
3158         struct device *dev;
3159
3160         dev = class_find_device(&spi_master_class, NULL, node,
3161                                 __spi_of_master_match);
3162         if (!dev)
3163                 return NULL;
3164
3165         /* reference got in class_find_device */
3166         return container_of(dev, struct spi_master, dev);
3167 }
3168
3169 static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3170                          void *arg)
3171 {
3172         struct of_reconfig_data *rd = arg;
3173         struct spi_master *master;
3174         struct spi_device *spi;
3175
3176         switch (of_reconfig_get_state_change(action, arg)) {
3177         case OF_RECONFIG_CHANGE_ADD:
3178                 master = of_find_spi_master_by_node(rd->dn->parent);
3179                 if (master == NULL)
3180                         return NOTIFY_OK;       /* not for us */
3181
3182                 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3183                         put_device(&master->dev);
3184                         return NOTIFY_OK;
3185                 }
3186
3187                 spi = of_register_spi_device(master, rd->dn);
3188                 put_device(&master->dev);
3189
3190                 if (IS_ERR(spi)) {
3191                         pr_err("%s: failed to create for '%s'\n",
3192                                         __func__, rd->dn->full_name);
3193                         of_node_clear_flag(rd->dn, OF_POPULATED);
3194                         return notifier_from_errno(PTR_ERR(spi));
3195                 }
3196                 break;
3197
3198         case OF_RECONFIG_CHANGE_REMOVE:
3199                 /* already depopulated? */
3200                 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3201                         return NOTIFY_OK;
3202
3203                 /* find our device by node */
3204                 spi = of_find_spi_device_by_node(rd->dn);
3205                 if (spi == NULL)
3206                         return NOTIFY_OK;       /* no? not meant for us */
3207
3208                 /* unregister takes one ref away */
3209                 spi_unregister_device(spi);
3210
3211                 /* and put the reference of the find */
3212                 put_device(&spi->dev);
3213                 break;
3214         }
3215
3216         return NOTIFY_OK;
3217 }
3218
3219 static struct notifier_block spi_of_notifier = {
3220         .notifier_call = of_spi_notify,
3221 };
3222 #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3223 extern struct notifier_block spi_of_notifier;
3224 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3225
3226 #if IS_ENABLED(CONFIG_ACPI)
3227 static int spi_acpi_master_match(struct device *dev, const void *data)
3228 {
3229         return ACPI_COMPANION(dev->parent) == data;
3230 }
3231
3232 static int spi_acpi_device_match(struct device *dev, void *data)
3233 {
3234         return ACPI_COMPANION(dev) == data;
3235 }
3236
3237 static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device *adev)
3238 {
3239         struct device *dev;
3240
3241         dev = class_find_device(&spi_master_class, NULL, adev,
3242                                 spi_acpi_master_match);
3243         if (!dev)
3244                 return NULL;
3245
3246         return container_of(dev, struct spi_master, dev);
3247 }
3248
3249 static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3250 {
3251         struct device *dev;
3252
3253         dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3254
3255         return dev ? to_spi_device(dev) : NULL;
3256 }
3257
3258 static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3259                            void *arg)
3260 {
3261         struct acpi_device *adev = arg;
3262         struct spi_master *master;
3263         struct spi_device *spi;
3264
3265         switch (value) {
3266         case ACPI_RECONFIG_DEVICE_ADD:
3267                 master = acpi_spi_find_master_by_adev(adev->parent);
3268                 if (!master)
3269                         break;
3270
3271                 acpi_register_spi_device(master, adev);
3272                 put_device(&master->dev);
3273                 break;
3274         case ACPI_RECONFIG_DEVICE_REMOVE:
3275                 if (!acpi_device_enumerated(adev))
3276                         break;
3277
3278                 spi = acpi_spi_find_device_by_adev(adev);
3279                 if (!spi)
3280                         break;
3281
3282                 spi_unregister_device(spi);
3283                 put_device(&spi->dev);
3284                 break;
3285         }
3286
3287         return NOTIFY_OK;
3288 }
3289
3290 static struct notifier_block spi_acpi_notifier = {
3291         .notifier_call = acpi_spi_notify,
3292 };
3293 #else
3294 extern struct notifier_block spi_acpi_notifier;
3295 #endif
3296
3297 static int __init spi_init(void)
3298 {
3299         int     status;
3300
3301         buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
3302         if (!buf) {
3303                 status = -ENOMEM;
3304                 goto err0;
3305         }
3306
3307         status = bus_register(&spi_bus_type);
3308         if (status < 0)
3309                 goto err1;
3310
3311         status = class_register(&spi_master_class);
3312         if (status < 0)
3313                 goto err2;
3314
3315         if (IS_ENABLED(CONFIG_OF_DYNAMIC))
3316                 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3317         if (IS_ENABLED(CONFIG_ACPI))
3318                 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
3319
3320         return 0;
3321
3322 err2:
3323         bus_unregister(&spi_bus_type);
3324 err1:
3325         kfree(buf);
3326         buf = NULL;
3327 err0:
3328         return status;
3329 }
3330
3331 /* board_info is normally registered in arch_initcall(),
3332  * but even essential drivers wait till later
3333  *