Merge branch 'spi-5.1' into spi-5.2
[sfrench/cifs-2.6.git] / drivers / spi / spi.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 // SPI init/core code
3 //
4 // Copyright (C) 2005 David Brownell
5 // Copyright (C) 2008 Secret Lab Technologies Ltd.
6
7 #include <linux/kernel.h>
8 #include <linux/device.h>
9 #include <linux/init.h>
10 #include <linux/cache.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/dmaengine.h>
13 #include <linux/mutex.h>
14 #include <linux/of_device.h>
15 #include <linux/of_irq.h>
16 #include <linux/clk/clk-conf.h>
17 #include <linux/slab.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/spi/spi.h>
20 #include <linux/spi/spi-mem.h>
21 #include <linux/of_gpio.h>
22 #include <linux/gpio/consumer.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/pm_domain.h>
25 #include <linux/property.h>
26 #include <linux/export.h>
27 #include <linux/sched/rt.h>
28 #include <uapi/linux/sched/types.h>
29 #include <linux/delay.h>
30 #include <linux/kthread.h>
31 #include <linux/ioport.h>
32 #include <linux/acpi.h>
33 #include <linux/highmem.h>
34 #include <linux/idr.h>
35 #include <linux/platform_data/x86/apple.h>
36
37 #define CREATE_TRACE_POINTS
38 #include <trace/events/spi.h>
39 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start);
40 EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop);
41
42 #include "internals.h"
43
44 static DEFINE_IDR(spi_master_idr);
45
46 static void spidev_release(struct device *dev)
47 {
48         struct spi_device       *spi = to_spi_device(dev);
49
50         /* spi controllers may cleanup for released devices */
51         if (spi->controller->cleanup)
52                 spi->controller->cleanup(spi);
53
54         spi_controller_put(spi->controller);
55         kfree(spi->driver_override);
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 static ssize_t driver_override_store(struct device *dev,
74                                      struct device_attribute *a,
75                                      const char *buf, size_t count)
76 {
77         struct spi_device *spi = to_spi_device(dev);
78         const char *end = memchr(buf, '\n', count);
79         const size_t len = end ? end - buf : count;
80         const char *driver_override, *old;
81
82         /* We need to keep extra room for a newline when displaying value */
83         if (len >= (PAGE_SIZE - 1))
84                 return -EINVAL;
85
86         driver_override = kstrndup(buf, len, GFP_KERNEL);
87         if (!driver_override)
88                 return -ENOMEM;
89
90         device_lock(dev);
91         old = spi->driver_override;
92         if (len) {
93                 spi->driver_override = driver_override;
94         } else {
95                 /* Emptry string, disable driver override */
96                 spi->driver_override = NULL;
97                 kfree(driver_override);
98         }
99         device_unlock(dev);
100         kfree(old);
101
102         return count;
103 }
104
105 static ssize_t driver_override_show(struct device *dev,
106                                     struct device_attribute *a, char *buf)
107 {
108         const struct spi_device *spi = to_spi_device(dev);
109         ssize_t len;
110
111         device_lock(dev);
112         len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
113         device_unlock(dev);
114         return len;
115 }
116 static DEVICE_ATTR_RW(driver_override);
117
118 #define SPI_STATISTICS_ATTRS(field, file)                               \
119 static ssize_t spi_controller_##field##_show(struct device *dev,        \
120                                              struct device_attribute *attr, \
121                                              char *buf)                 \
122 {                                                                       \
123         struct spi_controller *ctlr = container_of(dev,                 \
124                                          struct spi_controller, dev);   \
125         return spi_statistics_##field##_show(&ctlr->statistics, buf);   \
126 }                                                                       \
127 static struct device_attribute dev_attr_spi_controller_##field = {      \
128         .attr = { .name = file, .mode = 0444 },                         \
129         .show = spi_controller_##field##_show,                          \
130 };                                                                      \
131 static ssize_t spi_device_##field##_show(struct device *dev,            \
132                                          struct device_attribute *attr, \
133                                         char *buf)                      \
134 {                                                                       \
135         struct spi_device *spi = to_spi_device(dev);                    \
136         return spi_statistics_##field##_show(&spi->statistics, buf);    \
137 }                                                                       \
138 static struct device_attribute dev_attr_spi_device_##field = {          \
139         .attr = { .name = file, .mode = 0444 },                         \
140         .show = spi_device_##field##_show,                              \
141 }
142
143 #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string)      \
144 static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
145                                             char *buf)                  \
146 {                                                                       \
147         unsigned long flags;                                            \
148         ssize_t len;                                                    \
149         spin_lock_irqsave(&stat->lock, flags);                          \
150         len = sprintf(buf, format_string, stat->field);                 \
151         spin_unlock_irqrestore(&stat->lock, flags);                     \
152         return len;                                                     \
153 }                                                                       \
154 SPI_STATISTICS_ATTRS(name, file)
155
156 #define SPI_STATISTICS_SHOW(field, format_string)                       \
157         SPI_STATISTICS_SHOW_NAME(field, __stringify(field),             \
158                                  field, format_string)
159
160 SPI_STATISTICS_SHOW(messages, "%lu");
161 SPI_STATISTICS_SHOW(transfers, "%lu");
162 SPI_STATISTICS_SHOW(errors, "%lu");
163 SPI_STATISTICS_SHOW(timedout, "%lu");
164
165 SPI_STATISTICS_SHOW(spi_sync, "%lu");
166 SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
167 SPI_STATISTICS_SHOW(spi_async, "%lu");
168
169 SPI_STATISTICS_SHOW(bytes, "%llu");
170 SPI_STATISTICS_SHOW(bytes_rx, "%llu");
171 SPI_STATISTICS_SHOW(bytes_tx, "%llu");
172
173 #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number)              \
174         SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index,           \
175                                  "transfer_bytes_histo_" number,        \
176                                  transfer_bytes_histo[index],  "%lu")
177 SPI_STATISTICS_TRANSFER_BYTES_HISTO(0,  "0-1");
178 SPI_STATISTICS_TRANSFER_BYTES_HISTO(1,  "2-3");
179 SPI_STATISTICS_TRANSFER_BYTES_HISTO(2,  "4-7");
180 SPI_STATISTICS_TRANSFER_BYTES_HISTO(3,  "8-15");
181 SPI_STATISTICS_TRANSFER_BYTES_HISTO(4,  "16-31");
182 SPI_STATISTICS_TRANSFER_BYTES_HISTO(5,  "32-63");
183 SPI_STATISTICS_TRANSFER_BYTES_HISTO(6,  "64-127");
184 SPI_STATISTICS_TRANSFER_BYTES_HISTO(7,  "128-255");
185 SPI_STATISTICS_TRANSFER_BYTES_HISTO(8,  "256-511");
186 SPI_STATISTICS_TRANSFER_BYTES_HISTO(9,  "512-1023");
187 SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
188 SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
189 SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
190 SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
191 SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
192 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
193 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
194
195 SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
196
197 static struct attribute *spi_dev_attrs[] = {
198         &dev_attr_modalias.attr,
199         &dev_attr_driver_override.attr,
200         NULL,
201 };
202
203 static const struct attribute_group spi_dev_group = {
204         .attrs  = spi_dev_attrs,
205 };
206
207 static struct attribute *spi_device_statistics_attrs[] = {
208         &dev_attr_spi_device_messages.attr,
209         &dev_attr_spi_device_transfers.attr,
210         &dev_attr_spi_device_errors.attr,
211         &dev_attr_spi_device_timedout.attr,
212         &dev_attr_spi_device_spi_sync.attr,
213         &dev_attr_spi_device_spi_sync_immediate.attr,
214         &dev_attr_spi_device_spi_async.attr,
215         &dev_attr_spi_device_bytes.attr,
216         &dev_attr_spi_device_bytes_rx.attr,
217         &dev_attr_spi_device_bytes_tx.attr,
218         &dev_attr_spi_device_transfer_bytes_histo0.attr,
219         &dev_attr_spi_device_transfer_bytes_histo1.attr,
220         &dev_attr_spi_device_transfer_bytes_histo2.attr,
221         &dev_attr_spi_device_transfer_bytes_histo3.attr,
222         &dev_attr_spi_device_transfer_bytes_histo4.attr,
223         &dev_attr_spi_device_transfer_bytes_histo5.attr,
224         &dev_attr_spi_device_transfer_bytes_histo6.attr,
225         &dev_attr_spi_device_transfer_bytes_histo7.attr,
226         &dev_attr_spi_device_transfer_bytes_histo8.attr,
227         &dev_attr_spi_device_transfer_bytes_histo9.attr,
228         &dev_attr_spi_device_transfer_bytes_histo10.attr,
229         &dev_attr_spi_device_transfer_bytes_histo11.attr,
230         &dev_attr_spi_device_transfer_bytes_histo12.attr,
231         &dev_attr_spi_device_transfer_bytes_histo13.attr,
232         &dev_attr_spi_device_transfer_bytes_histo14.attr,
233         &dev_attr_spi_device_transfer_bytes_histo15.attr,
234         &dev_attr_spi_device_transfer_bytes_histo16.attr,
235         &dev_attr_spi_device_transfers_split_maxsize.attr,
236         NULL,
237 };
238
239 static const struct attribute_group spi_device_statistics_group = {
240         .name  = "statistics",
241         .attrs  = spi_device_statistics_attrs,
242 };
243
244 static const struct attribute_group *spi_dev_groups[] = {
245         &spi_dev_group,
246         &spi_device_statistics_group,
247         NULL,
248 };
249
250 static struct attribute *spi_controller_statistics_attrs[] = {
251         &dev_attr_spi_controller_messages.attr,
252         &dev_attr_spi_controller_transfers.attr,
253         &dev_attr_spi_controller_errors.attr,
254         &dev_attr_spi_controller_timedout.attr,
255         &dev_attr_spi_controller_spi_sync.attr,
256         &dev_attr_spi_controller_spi_sync_immediate.attr,
257         &dev_attr_spi_controller_spi_async.attr,
258         &dev_attr_spi_controller_bytes.attr,
259         &dev_attr_spi_controller_bytes_rx.attr,
260         &dev_attr_spi_controller_bytes_tx.attr,
261         &dev_attr_spi_controller_transfer_bytes_histo0.attr,
262         &dev_attr_spi_controller_transfer_bytes_histo1.attr,
263         &dev_attr_spi_controller_transfer_bytes_histo2.attr,
264         &dev_attr_spi_controller_transfer_bytes_histo3.attr,
265         &dev_attr_spi_controller_transfer_bytes_histo4.attr,
266         &dev_attr_spi_controller_transfer_bytes_histo5.attr,
267         &dev_attr_spi_controller_transfer_bytes_histo6.attr,
268         &dev_attr_spi_controller_transfer_bytes_histo7.attr,
269         &dev_attr_spi_controller_transfer_bytes_histo8.attr,
270         &dev_attr_spi_controller_transfer_bytes_histo9.attr,
271         &dev_attr_spi_controller_transfer_bytes_histo10.attr,
272         &dev_attr_spi_controller_transfer_bytes_histo11.attr,
273         &dev_attr_spi_controller_transfer_bytes_histo12.attr,
274         &dev_attr_spi_controller_transfer_bytes_histo13.attr,
275         &dev_attr_spi_controller_transfer_bytes_histo14.attr,
276         &dev_attr_spi_controller_transfer_bytes_histo15.attr,
277         &dev_attr_spi_controller_transfer_bytes_histo16.attr,
278         &dev_attr_spi_controller_transfers_split_maxsize.attr,
279         NULL,
280 };
281
282 static const struct attribute_group spi_controller_statistics_group = {
283         .name  = "statistics",
284         .attrs  = spi_controller_statistics_attrs,
285 };
286
287 static const struct attribute_group *spi_master_groups[] = {
288         &spi_controller_statistics_group,
289         NULL,
290 };
291
292 void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
293                                        struct spi_transfer *xfer,
294                                        struct spi_controller *ctlr)
295 {
296         unsigned long flags;
297         int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
298
299         if (l2len < 0)
300                 l2len = 0;
301
302         spin_lock_irqsave(&stats->lock, flags);
303
304         stats->transfers++;
305         stats->transfer_bytes_histo[l2len]++;
306
307         stats->bytes += xfer->len;
308         if ((xfer->tx_buf) &&
309             (xfer->tx_buf != ctlr->dummy_tx))
310                 stats->bytes_tx += xfer->len;
311         if ((xfer->rx_buf) &&
312             (xfer->rx_buf != ctlr->dummy_rx))
313                 stats->bytes_rx += xfer->len;
314
315         spin_unlock_irqrestore(&stats->lock, flags);
316 }
317 EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
318
319 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
320  * and the sysfs version makes coldplug work too.
321  */
322
323 static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
324                                                 const struct spi_device *sdev)
325 {
326         while (id->name[0]) {
327                 if (!strcmp(sdev->modalias, id->name))
328                         return id;
329                 id++;
330         }
331         return NULL;
332 }
333
334 const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
335 {
336         const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
337
338         return spi_match_id(sdrv->id_table, sdev);
339 }
340 EXPORT_SYMBOL_GPL(spi_get_device_id);
341
342 static int spi_match_device(struct device *dev, struct device_driver *drv)
343 {
344         const struct spi_device *spi = to_spi_device(dev);
345         const struct spi_driver *sdrv = to_spi_driver(drv);
346
347         /* Check override first, and if set, only use the named driver */
348         if (spi->driver_override)
349                 return strcmp(spi->driver_override, drv->name) == 0;
350
351         /* Attempt an OF style match */
352         if (of_driver_match_device(dev, drv))
353                 return 1;
354
355         /* Then try ACPI */
356         if (acpi_driver_match_device(dev, drv))
357                 return 1;
358
359         if (sdrv->id_table)
360                 return !!spi_match_id(sdrv->id_table, spi);
361
362         return strcmp(spi->modalias, drv->name) == 0;
363 }
364
365 static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
366 {
367         const struct spi_device         *spi = to_spi_device(dev);
368         int rc;
369
370         rc = acpi_device_uevent_modalias(dev, env);
371         if (rc != -ENODEV)
372                 return rc;
373
374         return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
375 }
376
377 struct bus_type spi_bus_type = {
378         .name           = "spi",
379         .dev_groups     = spi_dev_groups,
380         .match          = spi_match_device,
381         .uevent         = spi_uevent,
382 };
383 EXPORT_SYMBOL_GPL(spi_bus_type);
384
385
386 static int spi_drv_probe(struct device *dev)
387 {
388         const struct spi_driver         *sdrv = to_spi_driver(dev->driver);
389         struct spi_device               *spi = to_spi_device(dev);
390         int ret;
391
392         ret = of_clk_set_defaults(dev->of_node, false);
393         if (ret)
394                 return ret;
395
396         if (dev->of_node) {
397                 spi->irq = of_irq_get(dev->of_node, 0);
398                 if (spi->irq == -EPROBE_DEFER)
399                         return -EPROBE_DEFER;
400                 if (spi->irq < 0)
401                         spi->irq = 0;
402         }
403
404         ret = dev_pm_domain_attach(dev, true);
405         if (ret)
406                 return ret;
407
408         ret = sdrv->probe(spi);
409         if (ret)
410                 dev_pm_domain_detach(dev, true);
411
412         return ret;
413 }
414
415 static int spi_drv_remove(struct device *dev)
416 {
417         const struct spi_driver         *sdrv = to_spi_driver(dev->driver);
418         int ret;
419
420         ret = sdrv->remove(to_spi_device(dev));
421         dev_pm_domain_detach(dev, true);
422
423         return ret;
424 }
425
426 static void spi_drv_shutdown(struct device *dev)
427 {
428         const struct spi_driver         *sdrv = to_spi_driver(dev->driver);
429
430         sdrv->shutdown(to_spi_device(dev));
431 }
432
433 /**
434  * __spi_register_driver - register a SPI driver
435  * @owner: owner module of the driver to register
436  * @sdrv: the driver to register
437  * Context: can sleep
438  *
439  * Return: zero on success, else a negative error code.
440  */
441 int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
442 {
443         sdrv->driver.owner = owner;
444         sdrv->driver.bus = &spi_bus_type;
445         if (sdrv->probe)
446                 sdrv->driver.probe = spi_drv_probe;
447         if (sdrv->remove)
448                 sdrv->driver.remove = spi_drv_remove;
449         if (sdrv->shutdown)
450                 sdrv->driver.shutdown = spi_drv_shutdown;
451         return driver_register(&sdrv->driver);
452 }
453 EXPORT_SYMBOL_GPL(__spi_register_driver);
454
455 /*-------------------------------------------------------------------------*/
456
457 /* SPI devices should normally not be created by SPI device drivers; that
458  * would make them board-specific.  Similarly with SPI controller drivers.
459  * Device registration normally goes into like arch/.../mach.../board-YYY.c
460  * with other readonly (flashable) information about mainboard devices.
461  */
462
463 struct boardinfo {
464         struct list_head        list;
465         struct spi_board_info   board_info;
466 };
467
468 static LIST_HEAD(board_list);
469 static LIST_HEAD(spi_controller_list);
470
471 /*
472  * Used to protect add/del opertion for board_info list and
473  * spi_controller list, and their matching process
474  * also used to protect object of type struct idr
475  */
476 static DEFINE_MUTEX(board_lock);
477
478 /**
479  * spi_alloc_device - Allocate a new SPI device
480  * @ctlr: Controller to which device is connected
481  * Context: can sleep
482  *
483  * Allows a driver to allocate and initialize a spi_device without
484  * registering it immediately.  This allows a driver to directly
485  * fill the spi_device with device parameters before calling
486  * spi_add_device() on it.
487  *
488  * Caller is responsible to call spi_add_device() on the returned
489  * spi_device structure to add it to the SPI controller.  If the caller
490  * needs to discard the spi_device without adding it, then it should
491  * call spi_dev_put() on it.
492  *
493  * Return: a pointer to the new device, or NULL.
494  */
495 struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
496 {
497         struct spi_device       *spi;
498
499         if (!spi_controller_get(ctlr))
500                 return NULL;
501
502         spi = kzalloc(sizeof(*spi), GFP_KERNEL);
503         if (!spi) {
504                 spi_controller_put(ctlr);
505                 return NULL;
506         }
507
508         spi->master = spi->controller = ctlr;
509         spi->dev.parent = &ctlr->dev;
510         spi->dev.bus = &spi_bus_type;
511         spi->dev.release = spidev_release;
512         spi->cs_gpio = -ENOENT;
513
514         spin_lock_init(&spi->statistics.lock);
515
516         device_initialize(&spi->dev);
517         return spi;
518 }
519 EXPORT_SYMBOL_GPL(spi_alloc_device);
520
521 static void spi_dev_set_name(struct spi_device *spi)
522 {
523         struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
524
525         if (adev) {
526                 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
527                 return;
528         }
529
530         dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
531                      spi->chip_select);
532 }
533
534 static int spi_dev_check(struct device *dev, void *data)
535 {
536         struct spi_device *spi = to_spi_device(dev);
537         struct spi_device *new_spi = data;
538
539         if (spi->controller == new_spi->controller &&
540             spi->chip_select == new_spi->chip_select)
541                 return -EBUSY;
542         return 0;
543 }
544
545 /**
546  * spi_add_device - Add spi_device allocated with spi_alloc_device
547  * @spi: spi_device to register
548  *
549  * Companion function to spi_alloc_device.  Devices allocated with
550  * spi_alloc_device can be added onto the spi bus with this function.
551  *
552  * Return: 0 on success; negative errno on failure
553  */
554 int spi_add_device(struct spi_device *spi)
555 {
556         static DEFINE_MUTEX(spi_add_lock);
557         struct spi_controller *ctlr = spi->controller;
558         struct device *dev = ctlr->dev.parent;
559         int status;
560
561         /* Chipselects are numbered 0..max; validate. */
562         if (spi->chip_select >= ctlr->num_chipselect) {
563                 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
564                         ctlr->num_chipselect);
565                 return -EINVAL;
566         }
567
568         /* Set the bus ID string */
569         spi_dev_set_name(spi);
570
571         /* We need to make sure there's no other device with this
572          * chipselect **BEFORE** we call setup(), else we'll trash
573          * its configuration.  Lock against concurrent add() calls.
574          */
575         mutex_lock(&spi_add_lock);
576
577         status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
578         if (status) {
579                 dev_err(dev, "chipselect %d already in use\n",
580                                 spi->chip_select);
581                 goto done;
582         }
583
584         /* Descriptors take precedence */
585         if (ctlr->cs_gpiods)
586                 spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
587         else if (ctlr->cs_gpios)
588                 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
589
590         /* Drivers may modify this initial i/o setup, but will
591          * normally rely on the device being setup.  Devices
592          * using SPI_CS_HIGH can't coexist well otherwise...
593          */
594         status = spi_setup(spi);
595         if (status < 0) {
596                 dev_err(dev, "can't setup %s, status %d\n",
597                                 dev_name(&spi->dev), status);
598                 goto done;
599         }
600
601         /* Device may be bound to an active driver when this returns */
602         status = device_add(&spi->dev);
603         if (status < 0)
604                 dev_err(dev, "can't add %s, status %d\n",
605                                 dev_name(&spi->dev), status);
606         else
607                 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
608
609 done:
610         mutex_unlock(&spi_add_lock);
611         return status;
612 }
613 EXPORT_SYMBOL_GPL(spi_add_device);
614
615 /**
616  * spi_new_device - instantiate one new SPI device
617  * @ctlr: Controller to which device is connected
618  * @chip: Describes the SPI device
619  * Context: can sleep
620  *
621  * On typical mainboards, this is purely internal; and it's not needed
622  * after board init creates the hard-wired devices.  Some development
623  * platforms may not be able to use spi_register_board_info though, and
624  * this is exported so that for example a USB or parport based adapter
625  * driver could add devices (which it would learn about out-of-band).
626  *
627  * Return: the new device, or NULL.
628  */
629 struct spi_device *spi_new_device(struct spi_controller *ctlr,
630                                   struct spi_board_info *chip)
631 {
632         struct spi_device       *proxy;
633         int                     status;
634
635         /* NOTE:  caller did any chip->bus_num checks necessary.
636          *
637          * Also, unless we change the return value convention to use
638          * error-or-pointer (not NULL-or-pointer), troubleshootability
639          * suggests syslogged diagnostics are best here (ugh).
640          */
641
642         proxy = spi_alloc_device(ctlr);
643         if (!proxy)
644                 return NULL;
645
646         WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
647
648         proxy->chip_select = chip->chip_select;
649         proxy->max_speed_hz = chip->max_speed_hz;
650         proxy->mode = chip->mode;
651         proxy->irq = chip->irq;
652         strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
653         proxy->dev.platform_data = (void *) chip->platform_data;
654         proxy->controller_data = chip->controller_data;
655         proxy->controller_state = NULL;
656
657         if (chip->properties) {
658                 status = device_add_properties(&proxy->dev, chip->properties);
659                 if (status) {
660                         dev_err(&ctlr->dev,
661                                 "failed to add properties to '%s': %d\n",
662                                 chip->modalias, status);
663                         goto err_dev_put;
664                 }
665         }
666
667         status = spi_add_device(proxy);
668         if (status < 0)
669                 goto err_remove_props;
670
671         return proxy;
672
673 err_remove_props:
674         if (chip->properties)
675                 device_remove_properties(&proxy->dev);
676 err_dev_put:
677         spi_dev_put(proxy);
678         return NULL;
679 }
680 EXPORT_SYMBOL_GPL(spi_new_device);
681
682 /**
683  * spi_unregister_device - unregister a single SPI device
684  * @spi: spi_device to unregister
685  *
686  * Start making the passed SPI device vanish. Normally this would be handled
687  * by spi_unregister_controller().
688  */
689 void spi_unregister_device(struct spi_device *spi)
690 {
691         if (!spi)
692                 return;
693
694         if (spi->dev.of_node) {
695                 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
696                 of_node_put(spi->dev.of_node);
697         }
698         if (ACPI_COMPANION(&spi->dev))
699                 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
700         device_unregister(&spi->dev);
701 }
702 EXPORT_SYMBOL_GPL(spi_unregister_device);
703
704 static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
705                                               struct spi_board_info *bi)
706 {
707         struct spi_device *dev;
708
709         if (ctlr->bus_num != bi->bus_num)
710                 return;
711
712         dev = spi_new_device(ctlr, bi);
713         if (!dev)
714                 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
715                         bi->modalias);
716 }
717
718 /**
719  * spi_register_board_info - register SPI devices for a given board
720  * @info: array of chip descriptors
721  * @n: how many descriptors are provided
722  * Context: can sleep
723  *
724  * Board-specific early init code calls this (probably during arch_initcall)
725  * with segments of the SPI device table.  Any device nodes are created later,
726  * after the relevant parent SPI controller (bus_num) is defined.  We keep
727  * this table of devices forever, so that reloading a controller driver will
728  * not make Linux forget about these hard-wired devices.
729  *
730  * Other code can also call this, e.g. a particular add-on board might provide
731  * SPI devices through its expansion connector, so code initializing that board
732  * would naturally declare its SPI devices.
733  *
734  * The board info passed can safely be __initdata ... but be careful of
735  * any embedded pointers (platform_data, etc), they're copied as-is.
736  * Device properties are deep-copied though.
737  *
738  * Return: zero on success, else a negative error code.
739  */
740 int spi_register_board_info(struct spi_board_info const *info, unsigned n)
741 {
742         struct boardinfo *bi;
743         int i;
744
745         if (!n)
746                 return 0;
747
748         bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
749         if (!bi)
750                 return -ENOMEM;
751
752         for (i = 0; i < n; i++, bi++, info++) {
753                 struct spi_controller *ctlr;
754
755                 memcpy(&bi->board_info, info, sizeof(*info));
756                 if (info->properties) {
757                         bi->board_info.properties =
758                                         property_entries_dup(info->properties);
759                         if (IS_ERR(bi->board_info.properties))
760                                 return PTR_ERR(bi->board_info.properties);
761                 }
762
763                 mutex_lock(&board_lock);
764                 list_add_tail(&bi->list, &board_list);
765                 list_for_each_entry(ctlr, &spi_controller_list, list)
766                         spi_match_controller_to_boardinfo(ctlr,
767                                                           &bi->board_info);
768                 mutex_unlock(&board_lock);
769         }
770
771         return 0;
772 }
773
774 /*-------------------------------------------------------------------------*/
775
776 static void spi_set_cs(struct spi_device *spi, bool enable)
777 {
778         if (spi->mode & SPI_CS_HIGH)
779                 enable = !enable;
780
781         if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
782                 /*
783                  * Honour the SPI_NO_CS flag and invert the enable line, as
784                  * active low is default for SPI. Execution paths that handle
785                  * polarity inversion in gpiolib (such as device tree) will
786                  * enforce active high using the SPI_CS_HIGH resulting in a
787                  * double inversion through the code above.
788                  */
789                 if (!(spi->mode & SPI_NO_CS)) {
790                         if (spi->cs_gpiod)
791                                 gpiod_set_value_cansleep(spi->cs_gpiod,
792                                                          !enable);
793                         else
794                                 gpio_set_value_cansleep(spi->cs_gpio, !enable);
795                 }
796                 /* Some SPI masters need both GPIO CS & slave_select */
797                 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
798                     spi->controller->set_cs)
799                         spi->controller->set_cs(spi, !enable);
800         } else if (spi->controller->set_cs) {
801                 spi->controller->set_cs(spi, !enable);
802         }
803 }
804
805 #ifdef CONFIG_HAS_DMA
806 int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
807                 struct sg_table *sgt, void *buf, size_t len,
808                 enum dma_data_direction dir)
809 {
810         const bool vmalloced_buf = is_vmalloc_addr(buf);
811         unsigned int max_seg_size = dma_get_max_seg_size(dev);
812 #ifdef CONFIG_HIGHMEM
813         const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
814                                 (unsigned long)buf < (PKMAP_BASE +
815                                         (LAST_PKMAP * PAGE_SIZE)));
816 #else
817         const bool kmap_buf = false;
818 #endif
819         int desc_len;
820         int sgs;
821         struct page *vm_page;
822         struct scatterlist *sg;
823         void *sg_buf;
824         size_t min;
825         int i, ret;
826
827         if (vmalloced_buf || kmap_buf) {
828                 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
829                 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
830         } else if (virt_addr_valid(buf)) {
831                 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
832                 sgs = DIV_ROUND_UP(len, desc_len);
833         } else {
834                 return -EINVAL;
835         }
836
837         ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
838         if (ret != 0)
839                 return ret;
840
841         sg = &sgt->sgl[0];
842         for (i = 0; i < sgs; i++) {
843
844                 if (vmalloced_buf || kmap_buf) {
845                         /*
846                          * Next scatterlist entry size is the minimum between
847                          * the desc_len and the remaining buffer length that
848                          * fits in a page.
849                          */
850                         min = min_t(size_t, desc_len,
851                                     min_t(size_t, len,
852                                           PAGE_SIZE - offset_in_page(buf)));
853                         if (vmalloced_buf)
854                                 vm_page = vmalloc_to_page(buf);
855                         else
856                                 vm_page = kmap_to_page(buf);
857                         if (!vm_page) {
858                                 sg_free_table(sgt);
859                                 return -ENOMEM;
860                         }
861                         sg_set_page(sg, vm_page,
862                                     min, offset_in_page(buf));
863                 } else {
864                         min = min_t(size_t, len, desc_len);
865                         sg_buf = buf;
866                         sg_set_buf(sg, sg_buf, min);
867                 }
868
869                 buf += min;
870                 len -= min;
871                 sg = sg_next(sg);
872         }
873
874         ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
875         if (!ret)
876                 ret = -ENOMEM;
877         if (ret < 0) {
878                 sg_free_table(sgt);
879                 return ret;
880         }
881
882         sgt->nents = ret;
883
884         return 0;
885 }
886
887 void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
888                    struct sg_table *sgt, enum dma_data_direction dir)
889 {
890         if (sgt->orig_nents) {
891                 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
892                 sg_free_table(sgt);
893         }
894 }
895
896 static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
897 {
898         struct device *tx_dev, *rx_dev;
899         struct spi_transfer *xfer;
900         int ret;
901
902         if (!ctlr->can_dma)
903                 return 0;
904
905         if (ctlr->dma_tx)
906                 tx_dev = ctlr->dma_tx->device->dev;
907         else
908                 tx_dev = ctlr->dev.parent;
909
910         if (ctlr->dma_rx)
911                 rx_dev = ctlr->dma_rx->device->dev;
912         else
913                 rx_dev = ctlr->dev.parent;
914
915         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
916                 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
917                         continue;
918
919                 if (xfer->tx_buf != NULL) {
920                         ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
921                                           (void *)xfer->tx_buf, xfer->len,
922                                           DMA_TO_DEVICE);
923                         if (ret != 0)
924                                 return ret;
925                 }
926
927                 if (xfer->rx_buf != NULL) {
928                         ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
929                                           xfer->rx_buf, xfer->len,
930                                           DMA_FROM_DEVICE);
931                         if (ret != 0) {
932                                 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
933                                               DMA_TO_DEVICE);
934                                 return ret;
935                         }
936                 }
937         }
938
939         ctlr->cur_msg_mapped = true;
940
941         return 0;
942 }
943
944 static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
945 {
946         struct spi_transfer *xfer;
947         struct device *tx_dev, *rx_dev;
948
949         if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
950                 return 0;
951
952         if (ctlr->dma_tx)
953                 tx_dev = ctlr->dma_tx->device->dev;
954         else
955                 tx_dev = ctlr->dev.parent;
956
957         if (ctlr->dma_rx)
958                 rx_dev = ctlr->dma_rx->device->dev;
959         else
960                 rx_dev = ctlr->dev.parent;
961
962         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
963                 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
964                         continue;
965
966                 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
967                 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
968         }
969
970         return 0;
971 }
972 #else /* !CONFIG_HAS_DMA */
973 static inline int __spi_map_msg(struct spi_controller *ctlr,
974                                 struct spi_message *msg)
975 {
976         return 0;
977 }
978
979 static inline int __spi_unmap_msg(struct spi_controller *ctlr,
980                                   struct spi_message *msg)
981 {
982         return 0;
983 }
984 #endif /* !CONFIG_HAS_DMA */
985
986 static inline int spi_unmap_msg(struct spi_controller *ctlr,
987                                 struct spi_message *msg)
988 {
989         struct spi_transfer *xfer;
990
991         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
992                 /*
993                  * Restore the original value of tx_buf or rx_buf if they are
994                  * NULL.
995                  */
996                 if (xfer->tx_buf == ctlr->dummy_tx)
997                         xfer->tx_buf = NULL;
998                 if (xfer->rx_buf == ctlr->dummy_rx)
999                         xfer->rx_buf = NULL;
1000         }
1001
1002         return __spi_unmap_msg(ctlr, msg);
1003 }
1004
1005 static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1006 {
1007         struct spi_transfer *xfer;
1008         void *tmp;
1009         unsigned int max_tx, max_rx;
1010
1011         if (ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) {
1012                 max_tx = 0;
1013                 max_rx = 0;
1014
1015                 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1016                         if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1017                             !xfer->tx_buf)
1018                                 max_tx = max(xfer->len, max_tx);
1019                         if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1020                             !xfer->rx_buf)
1021                                 max_rx = max(xfer->len, max_rx);
1022                 }
1023
1024                 if (max_tx) {
1025                         tmp = krealloc(ctlr->dummy_tx, max_tx,
1026                                        GFP_KERNEL | GFP_DMA);
1027                         if (!tmp)
1028                                 return -ENOMEM;
1029                         ctlr->dummy_tx = tmp;
1030                         memset(tmp, 0, max_tx);
1031                 }
1032
1033                 if (max_rx) {
1034                         tmp = krealloc(ctlr->dummy_rx, max_rx,
1035                                        GFP_KERNEL | GFP_DMA);
1036                         if (!tmp)
1037                                 return -ENOMEM;
1038                         ctlr->dummy_rx = tmp;
1039                 }
1040
1041                 if (max_tx || max_rx) {
1042                         list_for_each_entry(xfer, &msg->transfers,
1043                                             transfer_list) {
1044                                 if (!xfer->len)
1045                                         continue;
1046                                 if (!xfer->tx_buf)
1047                                         xfer->tx_buf = ctlr->dummy_tx;
1048                                 if (!xfer->rx_buf)
1049                                         xfer->rx_buf = ctlr->dummy_rx;
1050                         }
1051                 }
1052         }
1053
1054         return __spi_map_msg(ctlr, msg);
1055 }
1056
1057 static int spi_transfer_wait(struct spi_controller *ctlr,
1058                              struct spi_message *msg,
1059                              struct spi_transfer *xfer)
1060 {
1061         struct spi_statistics *statm = &ctlr->statistics;
1062         struct spi_statistics *stats = &msg->spi->statistics;
1063         unsigned long long ms = 1;
1064
1065         if (spi_controller_is_slave(ctlr)) {
1066                 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1067                         dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1068                         return -EINTR;
1069                 }
1070         } else {
1071                 ms = 8LL * 1000LL * xfer->len;
1072                 do_div(ms, xfer->speed_hz);
1073                 ms += ms + 200; /* some tolerance */
1074
1075                 if (ms > UINT_MAX)
1076                         ms = UINT_MAX;
1077
1078                 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1079                                                  msecs_to_jiffies(ms));
1080
1081                 if (ms == 0) {
1082                         SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1083                         SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1084                         dev_err(&msg->spi->dev,
1085                                 "SPI transfer timed out\n");
1086                         return -ETIMEDOUT;
1087                 }
1088         }
1089
1090         return 0;
1091 }
1092
1093 /*
1094  * spi_transfer_one_message - Default implementation of transfer_one_message()
1095  *
1096  * This is a standard implementation of transfer_one_message() for
1097  * drivers which implement a transfer_one() operation.  It provides
1098  * standard handling of delays and chip select management.
1099  */
1100 static int spi_transfer_one_message(struct spi_controller *ctlr,
1101                                     struct spi_message *msg)
1102 {
1103         struct spi_transfer *xfer;
1104         bool keep_cs = false;
1105         int ret = 0;
1106         struct spi_statistics *statm = &ctlr->statistics;
1107         struct spi_statistics *stats = &msg->spi->statistics;
1108
1109         spi_set_cs(msg->spi, true);
1110
1111         SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1112         SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1113
1114         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1115                 trace_spi_transfer_start(msg, xfer);
1116
1117                 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1118                 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1119
1120                 if (xfer->tx_buf || xfer->rx_buf) {
1121                         reinit_completion(&ctlr->xfer_completion);
1122
1123                         ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1124                         if (ret < 0) {
1125                                 SPI_STATISTICS_INCREMENT_FIELD(statm,
1126                                                                errors);
1127                                 SPI_STATISTICS_INCREMENT_FIELD(stats,
1128                                                                errors);
1129                                 dev_err(&msg->spi->dev,
1130                                         "SPI transfer failed: %d\n", ret);
1131                                 goto out;
1132                         }
1133
1134                         if (ret > 0) {
1135                                 ret = spi_transfer_wait(ctlr, msg, xfer);
1136                                 if (ret < 0)
1137                                         msg->status = ret;
1138                         }
1139                 } else {
1140                         if (xfer->len)
1141                                 dev_err(&msg->spi->dev,
1142                                         "Bufferless transfer has length %u\n",
1143                                         xfer->len);
1144                 }
1145
1146                 trace_spi_transfer_stop(msg, xfer);
1147
1148                 if (msg->status != -EINPROGRESS)
1149                         goto out;
1150
1151                 if (xfer->delay_usecs) {
1152                         u16 us = xfer->delay_usecs;
1153
1154                         if (us <= 10)
1155                                 udelay(us);
1156                         else
1157                                 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1158                 }
1159
1160                 if (xfer->cs_change) {
1161                         if (list_is_last(&xfer->transfer_list,
1162                                          &msg->transfers)) {
1163                                 keep_cs = true;
1164                         } else {
1165                                 spi_set_cs(msg->spi, false);
1166                                 udelay(10);
1167                                 spi_set_cs(msg->spi, true);
1168                         }
1169                 }
1170
1171                 msg->actual_length += xfer->len;
1172         }
1173
1174 out:
1175         if (ret != 0 || !keep_cs)
1176                 spi_set_cs(msg->spi, false);
1177
1178         if (msg->status == -EINPROGRESS)
1179                 msg->status = ret;
1180
1181         if (msg->status && ctlr->handle_err)
1182                 ctlr->handle_err(ctlr, msg);
1183
1184         spi_res_release(ctlr, msg);
1185
1186         spi_finalize_current_message(ctlr);
1187
1188         return ret;
1189 }
1190
1191 /**
1192  * spi_finalize_current_transfer - report completion of a transfer
1193  * @ctlr: the controller reporting completion
1194  *
1195  * Called by SPI drivers using the core transfer_one_message()
1196  * implementation to notify it that the current interrupt driven
1197  * transfer has finished and the next one may be scheduled.
1198  */
1199 void spi_finalize_current_transfer(struct spi_controller *ctlr)
1200 {
1201         complete(&ctlr->xfer_completion);
1202 }
1203 EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1204
1205 /**
1206  * __spi_pump_messages - function which processes spi message queue
1207  * @ctlr: controller to process queue for
1208  * @in_kthread: true if we are in the context of the message pump thread
1209  *
1210  * This function checks if there is any spi message in the queue that
1211  * needs processing and if so call out to the driver to initialize hardware
1212  * and transfer each message.
1213  *
1214  * Note that it is called both from the kthread itself and also from
1215  * inside spi_sync(); the queue extraction handling at the top of the
1216  * function should deal with this safely.
1217  */
1218 static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1219 {
1220         unsigned long flags;
1221         bool was_busy = false;
1222         int ret;
1223
1224         /* Lock queue */
1225         spin_lock_irqsave(&ctlr->queue_lock, flags);
1226
1227         /* Make sure we are not already running a message */
1228         if (ctlr->cur_msg) {
1229                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1230                 return;
1231         }
1232
1233         /* If another context is idling the device then defer */
1234         if (ctlr->idling) {
1235                 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1236                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1237                 return;
1238         }
1239
1240         /* Check if the queue is idle */
1241         if (list_empty(&ctlr->queue) || !ctlr->running) {
1242                 if (!ctlr->busy) {
1243                         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1244                         return;
1245                 }
1246
1247                 /* Only do teardown in the thread */
1248                 if (!in_kthread) {
1249                         kthread_queue_work(&ctlr->kworker,
1250                                            &ctlr->pump_messages);
1251                         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1252                         return;
1253                 }
1254
1255                 ctlr->busy = false;
1256                 ctlr->idling = true;
1257                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1258
1259                 kfree(ctlr->dummy_rx);
1260                 ctlr->dummy_rx = NULL;
1261                 kfree(ctlr->dummy_tx);
1262                 ctlr->dummy_tx = NULL;
1263                 if (ctlr->unprepare_transfer_hardware &&
1264                     ctlr->unprepare_transfer_hardware(ctlr))
1265                         dev_err(&ctlr->dev,
1266                                 "failed to unprepare transfer hardware\n");
1267                 if (ctlr->auto_runtime_pm) {
1268                         pm_runtime_mark_last_busy(ctlr->dev.parent);
1269                         pm_runtime_put_autosuspend(ctlr->dev.parent);
1270                 }
1271                 trace_spi_controller_idle(ctlr);
1272
1273                 spin_lock_irqsave(&ctlr->queue_lock, flags);
1274                 ctlr->idling = false;
1275                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1276                 return;
1277         }
1278
1279         /* Extract head of queue */
1280         ctlr->cur_msg =
1281                 list_first_entry(&ctlr->queue, struct spi_message, queue);
1282
1283         list_del_init(&ctlr->cur_msg->queue);
1284         if (ctlr->busy)
1285                 was_busy = true;
1286         else
1287                 ctlr->busy = true;
1288         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1289
1290         mutex_lock(&ctlr->io_mutex);
1291
1292         if (!was_busy && ctlr->auto_runtime_pm) {
1293                 ret = pm_runtime_get_sync(ctlr->dev.parent);
1294                 if (ret < 0) {
1295                         pm_runtime_put_noidle(ctlr->dev.parent);
1296                         dev_err(&ctlr->dev, "Failed to power device: %d\n",
1297                                 ret);
1298                         mutex_unlock(&ctlr->io_mutex);
1299                         return;
1300                 }
1301         }
1302
1303         if (!was_busy)
1304                 trace_spi_controller_busy(ctlr);
1305
1306         if (!was_busy && ctlr->prepare_transfer_hardware) {
1307                 ret = ctlr->prepare_transfer_hardware(ctlr);
1308                 if (ret) {
1309                         dev_err(&ctlr->dev,
1310                                 "failed to prepare transfer hardware\n");
1311
1312                         if (ctlr->auto_runtime_pm)
1313                                 pm_runtime_put(ctlr->dev.parent);
1314                         mutex_unlock(&ctlr->io_mutex);
1315                         return;
1316                 }
1317         }
1318
1319         trace_spi_message_start(ctlr->cur_msg);
1320
1321         if (ctlr->prepare_message) {
1322                 ret = ctlr->prepare_message(ctlr, ctlr->cur_msg);
1323                 if (ret) {
1324                         dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1325                                 ret);
1326                         ctlr->cur_msg->status = ret;
1327                         spi_finalize_current_message(ctlr);
1328                         goto out;
1329                 }
1330                 ctlr->cur_msg_prepared = true;
1331         }
1332
1333         ret = spi_map_msg(ctlr, ctlr->cur_msg);
1334         if (ret) {
1335                 ctlr->cur_msg->status = ret;
1336                 spi_finalize_current_message(ctlr);
1337                 goto out;
1338         }
1339
1340         ret = ctlr->transfer_one_message(ctlr, ctlr->cur_msg);
1341         if (ret) {
1342                 dev_err(&ctlr->dev,
1343                         "failed to transfer one message from queue\n");
1344                 goto out;
1345         }
1346
1347 out:
1348         mutex_unlock(&ctlr->io_mutex);
1349
1350         /* Prod the scheduler in case transfer_one() was busy waiting */
1351         if (!ret)
1352                 cond_resched();
1353 }
1354
1355 /**
1356  * spi_pump_messages - kthread work function which processes spi message queue
1357  * @work: pointer to kthread work struct contained in the controller struct
1358  */
1359 static void spi_pump_messages(struct kthread_work *work)
1360 {
1361         struct spi_controller *ctlr =
1362                 container_of(work, struct spi_controller, pump_messages);
1363
1364         __spi_pump_messages(ctlr, true);
1365 }
1366
1367 static int spi_init_queue(struct spi_controller *ctlr)
1368 {
1369         struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1370
1371         ctlr->running = false;
1372         ctlr->busy = false;
1373
1374         kthread_init_worker(&ctlr->kworker);
1375         ctlr->kworker_task = kthread_run(kthread_worker_fn, &ctlr->kworker,
1376                                          "%s", dev_name(&ctlr->dev));
1377         if (IS_ERR(ctlr->kworker_task)) {
1378                 dev_err(&ctlr->dev, "failed to create message pump task\n");
1379                 return PTR_ERR(ctlr->kworker_task);
1380         }
1381         kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1382
1383         /*
1384          * Controller config will indicate if this controller should run the
1385          * message pump with high (realtime) priority to reduce the transfer
1386          * latency on the bus by minimising the delay between a transfer
1387          * request and the scheduling of the message pump thread. Without this
1388          * setting the message pump thread will remain at default priority.
1389          */
1390         if (ctlr->rt) {
1391                 dev_info(&ctlr->dev,
1392                         "will run message pump with realtime priority\n");
1393                 sched_setscheduler(ctlr->kworker_task, SCHED_FIFO, &param);
1394         }
1395
1396         return 0;
1397 }
1398
1399 /**
1400  * spi_get_next_queued_message() - called by driver to check for queued
1401  * messages
1402  * @ctlr: the controller to check for queued messages
1403  *
1404  * If there are more messages in the queue, the next message is returned from
1405  * this call.
1406  *
1407  * Return: the next message in the queue, else NULL if the queue is empty.
1408  */
1409 struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1410 {
1411         struct spi_message *next;
1412         unsigned long flags;
1413
1414         /* get a pointer to the next message, if any */
1415         spin_lock_irqsave(&ctlr->queue_lock, flags);
1416         next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1417                                         queue);
1418         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1419
1420         return next;
1421 }
1422 EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1423
1424 /**
1425  * spi_finalize_current_message() - the current message is complete
1426  * @ctlr: the controller to return the message to
1427  *
1428  * Called by the driver to notify the core that the message in the front of the
1429  * queue is complete and can be removed from the queue.
1430  */
1431 void spi_finalize_current_message(struct spi_controller *ctlr)
1432 {
1433         struct spi_message *mesg;
1434         unsigned long flags;
1435         int ret;
1436
1437         spin_lock_irqsave(&ctlr->queue_lock, flags);
1438         mesg = ctlr->cur_msg;
1439         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1440
1441         spi_unmap_msg(ctlr, mesg);
1442
1443         if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1444                 ret = ctlr->unprepare_message(ctlr, mesg);
1445                 if (ret) {
1446                         dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1447                                 ret);
1448                 }
1449         }
1450
1451         spin_lock_irqsave(&ctlr->queue_lock, flags);
1452         ctlr->cur_msg = NULL;
1453         ctlr->cur_msg_prepared = false;
1454         kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1455         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1456
1457         trace_spi_message_done(mesg);
1458
1459         mesg->state = NULL;
1460         if (mesg->complete)
1461                 mesg->complete(mesg->context);
1462 }
1463 EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1464
1465 static int spi_start_queue(struct spi_controller *ctlr)
1466 {
1467         unsigned long flags;
1468
1469         spin_lock_irqsave(&ctlr->queue_lock, flags);
1470
1471         if (ctlr->running || ctlr->busy) {
1472                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1473                 return -EBUSY;
1474         }
1475
1476         ctlr->running = true;
1477         ctlr->cur_msg = NULL;
1478         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1479
1480         kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1481
1482         return 0;
1483 }
1484
1485 static int spi_stop_queue(struct spi_controller *ctlr)
1486 {
1487         unsigned long flags;
1488         unsigned limit = 500;
1489         int ret = 0;
1490
1491         spin_lock_irqsave(&ctlr->queue_lock, flags);
1492
1493         /*
1494          * This is a bit lame, but is optimized for the common execution path.
1495          * A wait_queue on the ctlr->busy could be used, but then the common
1496          * execution path (pump_messages) would be required to call wake_up or
1497          * friends on every SPI message. Do this instead.
1498          */
1499         while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1500                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1501                 usleep_range(10000, 11000);
1502                 spin_lock_irqsave(&ctlr->queue_lock, flags);
1503         }
1504
1505         if (!list_empty(&ctlr->queue) || ctlr->busy)
1506                 ret = -EBUSY;
1507         else
1508                 ctlr->running = false;
1509
1510         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1511
1512         if (ret) {
1513                 dev_warn(&ctlr->dev, "could not stop message queue\n");
1514                 return ret;
1515         }
1516         return ret;
1517 }
1518
1519 static int spi_destroy_queue(struct spi_controller *ctlr)
1520 {
1521         int ret;
1522
1523         ret = spi_stop_queue(ctlr);
1524
1525         /*
1526          * kthread_flush_worker will block until all work is done.
1527          * If the reason that stop_queue timed out is that the work will never
1528          * finish, then it does no good to call flush/stop thread, so
1529          * return anyway.
1530          */
1531         if (ret) {
1532                 dev_err(&ctlr->dev, "problem destroying queue\n");
1533                 return ret;
1534         }
1535
1536         kthread_flush_worker(&ctlr->kworker);
1537         kthread_stop(ctlr->kworker_task);
1538
1539         return 0;
1540 }
1541
1542 static int __spi_queued_transfer(struct spi_device *spi,
1543                                  struct spi_message *msg,
1544                                  bool need_pump)
1545 {
1546         struct spi_controller *ctlr = spi->controller;
1547         unsigned long flags;
1548
1549         spin_lock_irqsave(&ctlr->queue_lock, flags);
1550
1551         if (!ctlr->running) {
1552                 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1553                 return -ESHUTDOWN;
1554         }
1555         msg->actual_length = 0;
1556         msg->status = -EINPROGRESS;
1557
1558         list_add_tail(&msg->queue, &ctlr->queue);
1559         if (!ctlr->busy && need_pump)
1560                 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1561
1562         spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1563         return 0;
1564 }
1565
1566 /**
1567  * spi_queued_transfer - transfer function for queued transfers
1568  * @spi: spi device which is requesting transfer
1569  * @msg: spi message which is to handled is queued to driver queue
1570  *
1571  * Return: zero on success, else a negative error code.
1572  */
1573 static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1574 {
1575         return __spi_queued_transfer(spi, msg, true);
1576 }
1577
1578 static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1579 {
1580         int ret;
1581
1582         ctlr->transfer = spi_queued_transfer;
1583         if (!ctlr->transfer_one_message)
1584                 ctlr->transfer_one_message = spi_transfer_one_message;
1585
1586         /* Initialize and start queue */
1587         ret = spi_init_queue(ctlr);
1588         if (ret) {
1589                 dev_err(&ctlr->dev, "problem initializing queue\n");
1590                 goto err_init_queue;
1591         }
1592         ctlr->queued = true;
1593         ret = spi_start_queue(ctlr);
1594         if (ret) {
1595                 dev_err(&ctlr->dev, "problem starting queue\n");
1596                 goto err_start_queue;
1597         }
1598
1599         return 0;
1600
1601 err_start_queue:
1602         spi_destroy_queue(ctlr);
1603 err_init_queue:
1604         return ret;
1605 }
1606
1607 /**
1608  * spi_flush_queue - Send all pending messages in the queue from the callers'
1609  *                   context
1610  * @ctlr: controller to process queue for
1611  *
1612  * This should be used when one wants to ensure all pending messages have been
1613  * sent before doing something. Is used by the spi-mem code to make sure SPI
1614  * memory operations do not preempt regular SPI transfers that have been queued
1615  * before the spi-mem operation.
1616  */
1617 void spi_flush_queue(struct spi_controller *ctlr)
1618 {
1619         if (ctlr->transfer == spi_queued_transfer)
1620                 __spi_pump_messages(ctlr, false);
1621 }
1622
1623 /*-------------------------------------------------------------------------*/
1624
1625 #if defined(CONFIG_OF)
1626 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1627                            struct device_node *nc)
1628 {
1629         u32 value;
1630         int rc;
1631
1632         /* Mode (clock phase/polarity/etc.) */
1633         if (of_property_read_bool(nc, "spi-cpha"))
1634                 spi->mode |= SPI_CPHA;
1635         if (of_property_read_bool(nc, "spi-cpol"))
1636                 spi->mode |= SPI_CPOL;
1637         if (of_property_read_bool(nc, "spi-3wire"))
1638                 spi->mode |= SPI_3WIRE;
1639         if (of_property_read_bool(nc, "spi-lsb-first"))
1640                 spi->mode |= SPI_LSB_FIRST;
1641
1642         /*
1643          * For descriptors associated with the device, polarity inversion is
1644          * handled in the gpiolib, so all chip selects are "active high" in
1645          * the logical sense, the gpiolib will invert the line if need be.
1646          */
1647         if (ctlr->use_gpio_descriptors)
1648                 spi->mode |= SPI_CS_HIGH;
1649         else if (of_property_read_bool(nc, "spi-cs-high"))
1650                 spi->mode |= SPI_CS_HIGH;
1651
1652         /* Device DUAL/QUAD mode */
1653         if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1654                 switch (value) {
1655                 case 1:
1656                         break;
1657                 case 2:
1658                         spi->mode |= SPI_TX_DUAL;
1659                         break;
1660                 case 4:
1661                         spi->mode |= SPI_TX_QUAD;
1662                         break;
1663                 case 8:
1664                         spi->mode |= SPI_TX_OCTAL;
1665                         break;
1666                 default:
1667                         dev_warn(&ctlr->dev,
1668                                 "spi-tx-bus-width %d not supported\n",
1669                                 value);
1670                         break;
1671                 }
1672         }
1673
1674         if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1675                 switch (value) {
1676                 case 1:
1677                         break;
1678                 case 2:
1679                         spi->mode |= SPI_RX_DUAL;
1680                         break;
1681                 case 4:
1682                         spi->mode |= SPI_RX_QUAD;
1683                         break;
1684                 case 8:
1685                         spi->mode |= SPI_RX_OCTAL;
1686                         break;
1687                 default:
1688                         dev_warn(&ctlr->dev,
1689                                 "spi-rx-bus-width %d not supported\n",
1690                                 value);
1691                         break;
1692                 }
1693         }
1694
1695         if (spi_controller_is_slave(ctlr)) {
1696                 if (!of_node_name_eq(nc, "slave")) {
1697                         dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
1698                                 nc);
1699                         return -EINVAL;
1700                 }
1701                 return 0;
1702         }
1703
1704         /* Device address */
1705         rc = of_property_read_u32(nc, "reg", &value);
1706         if (rc) {
1707                 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
1708                         nc, rc);
1709                 return rc;
1710         }
1711         spi->chip_select = value;
1712
1713         /* Device speed */
1714         rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1715         if (rc) {
1716                 dev_err(&ctlr->dev,
1717                         "%pOF has no valid 'spi-max-frequency' property (%d)\n", nc, rc);
1718                 return rc;
1719         }
1720         spi->max_speed_hz = value;
1721
1722         return 0;
1723 }
1724
1725 static struct spi_device *
1726 of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
1727 {
1728         struct spi_device *spi;
1729         int rc;
1730
1731         /* Alloc an spi_device */
1732         spi = spi_alloc_device(ctlr);
1733         if (!spi) {
1734                 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
1735                 rc = -ENOMEM;
1736                 goto err_out;
1737         }
1738
1739         /* Select device driver */
1740         rc = of_modalias_node(nc, spi->modalias,
1741                                 sizeof(spi->modalias));
1742         if (rc < 0) {
1743                 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
1744                 goto err_out;
1745         }
1746
1747         rc = of_spi_parse_dt(ctlr, spi, nc);
1748         if (rc)
1749                 goto err_out;
1750
1751         /* Store a pointer to the node in the device structure */
1752         of_node_get(nc);
1753         spi->dev.of_node = nc;
1754
1755         /* Register the new device */
1756         rc = spi_add_device(spi);
1757         if (rc) {
1758                 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
1759                 goto err_of_node_put;
1760         }
1761
1762         return spi;
1763
1764 err_of_node_put:
1765         of_node_put(nc);
1766 err_out:
1767         spi_dev_put(spi);
1768         return ERR_PTR(rc);
1769 }
1770
1771 /**
1772  * of_register_spi_devices() - Register child devices onto the SPI bus
1773  * @ctlr:       Pointer to spi_controller device
1774  *
1775  * Registers an spi_device for each child node of controller node which
1776  * represents a valid SPI slave.
1777  */
1778 static void of_register_spi_devices(struct spi_controller *ctlr)
1779 {
1780         struct spi_device *spi;
1781         struct device_node *nc;
1782
1783         if (!ctlr->dev.of_node)
1784                 return;
1785
1786         for_each_available_child_of_node(ctlr->dev.of_node, nc) {
1787                 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1788                         continue;
1789                 spi = of_register_spi_device(ctlr, nc);
1790                 if (IS_ERR(spi)) {
1791                         dev_warn(&ctlr->dev,
1792                                  "Failed to create SPI device for %pOF\n", nc);
1793                         of_node_clear_flag(nc, OF_POPULATED);
1794                 }
1795         }
1796 }
1797 #else
1798 static void of_register_spi_devices(struct spi_controller *ctlr) { }
1799 #endif
1800
1801 #ifdef CONFIG_ACPI
1802 static void acpi_spi_parse_apple_properties(struct spi_device *spi)
1803 {
1804         struct acpi_device *dev = ACPI_COMPANION(&spi->dev);
1805         const union acpi_object *obj;
1806
1807         if (!x86_apple_machine)
1808                 return;
1809
1810         if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
1811             && obj->buffer.length >= 4)
1812                 spi->max_speed_hz  = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
1813
1814         if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
1815             && obj->buffer.length == 8)
1816                 spi->bits_per_word = *(u64 *)obj->buffer.pointer;
1817
1818         if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
1819             && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
1820                 spi->mode |= SPI_LSB_FIRST;
1821
1822         if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
1823             && obj->buffer.length == 8 &&  *(u64 *)obj->buffer.pointer)
1824                 spi->mode |= SPI_CPOL;
1825
1826         if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
1827             && obj->buffer.length == 8 &&  *(u64 *)obj->buffer.pointer)
1828                 spi->mode |= SPI_CPHA;
1829 }
1830
1831 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1832 {
1833         struct spi_device *spi = data;
1834         struct spi_controller *ctlr = spi->controller;
1835
1836         if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1837                 struct acpi_resource_spi_serialbus *sb;
1838
1839                 sb = &ares->data.spi_serial_bus;
1840                 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1841                         /*
1842                          * ACPI DeviceSelection numbering is handled by the
1843                          * host controller driver in Windows and can vary
1844                          * from driver to driver. In Linux we always expect
1845                          * 0 .. max - 1 so we need to ask the driver to
1846                          * translate between the two schemes.
1847                          */
1848                         if (ctlr->fw_translate_cs) {
1849                                 int cs = ctlr->fw_translate_cs(ctlr,
1850                                                 sb->device_selection);
1851                                 if (cs < 0)
1852                                         return cs;
1853                                 spi->chip_select = cs;
1854                         } else {
1855                                 spi->chip_select = sb->device_selection;
1856                         }
1857
1858                         spi->max_speed_hz = sb->connection_speed;
1859
1860                         if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1861                                 spi->mode |= SPI_CPHA;
1862                         if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1863                                 spi->mode |= SPI_CPOL;
1864                         if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1865                                 spi->mode |= SPI_CS_HIGH;
1866                 }
1867         } else if (spi->irq < 0) {
1868                 struct resource r;
1869
1870                 if (acpi_dev_resource_interrupt(ares, 0, &r))
1871                         spi->irq = r.start;
1872         }
1873
1874         /* Always tell the ACPI core to skip this resource */
1875         return 1;
1876 }
1877
1878 static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
1879                                             struct acpi_device *adev)
1880 {
1881         struct list_head resource_list;
1882         struct spi_device *spi;
1883         int ret;
1884
1885         if (acpi_bus_get_status(adev) || !adev->status.present ||
1886             acpi_device_enumerated(adev))
1887                 return AE_OK;
1888
1889         spi = spi_alloc_device(ctlr);
1890         if (!spi) {
1891                 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
1892                         dev_name(&adev->dev));
1893                 return AE_NO_MEMORY;
1894         }
1895
1896         ACPI_COMPANION_SET(&spi->dev, adev);
1897         spi->irq = -1;
1898
1899         INIT_LIST_HEAD(&resource_list);
1900         ret = acpi_dev_get_resources(adev, &resource_list,
1901                                      acpi_spi_add_resource, spi);
1902         acpi_dev_free_resource_list(&resource_list);
1903
1904         acpi_spi_parse_apple_properties(spi);
1905
1906         if (ret < 0 || !spi->max_speed_hz) {
1907                 spi_dev_put(spi);
1908                 return AE_OK;
1909         }
1910
1911         acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
1912                           sizeof(spi->modalias));
1913
1914         if (spi->irq < 0)
1915                 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1916
1917         acpi_device_set_enumerated(adev);
1918
1919         adev->power.flags.ignore_parent = true;
1920         if (spi_add_device(spi)) {
1921                 adev->power.flags.ignore_parent = false;
1922                 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
1923                         dev_name(&adev->dev));
1924                 spi_dev_put(spi);
1925         }
1926
1927         return AE_OK;
1928 }
1929
1930 static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1931                                        void *data, void **return_value)
1932 {
1933         struct spi_controller *ctlr = data;
1934         struct acpi_device *adev;
1935
1936         if (acpi_bus_get_device(handle, &adev))
1937                 return AE_OK;
1938
1939         return acpi_register_spi_device(ctlr, adev);
1940 }
1941
1942 static void acpi_register_spi_devices(struct spi_controller *ctlr)
1943 {
1944         acpi_status status;
1945         acpi_handle handle;
1946
1947         handle = ACPI_HANDLE(ctlr->dev.parent);
1948         if (!handle)
1949                 return;
1950
1951         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1952                                      acpi_spi_add_device, NULL, ctlr, NULL);
1953         if (ACPI_FAILURE(status))
1954                 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
1955 }
1956 #else
1957 static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
1958 #endif /* CONFIG_ACPI */
1959
1960 static void spi_controller_release(struct device *dev)
1961 {
1962         struct spi_controller *ctlr;
1963
1964         ctlr = container_of(dev, struct spi_controller, dev);
1965         kfree(ctlr);
1966 }
1967
1968 static struct class spi_master_class = {
1969         .name           = "spi_master",
1970         .owner          = THIS_MODULE,
1971         .dev_release    = spi_controller_release,
1972         .dev_groups     = spi_master_groups,
1973 };
1974
1975 #ifdef CONFIG_SPI_SLAVE
1976 /**
1977  * spi_slave_abort - abort the ongoing transfer request on an SPI slave
1978  *                   controller
1979  * @spi: device used for the current transfer
1980  */
1981 int spi_slave_abort(struct spi_device *spi)
1982 {
1983         struct spi_controller *ctlr = spi->controller;
1984
1985         if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
1986                 return ctlr->slave_abort(ctlr);
1987
1988         return -ENOTSUPP;
1989 }
1990 EXPORT_SYMBOL_GPL(spi_slave_abort);
1991
1992 static int match_true(struct device *dev, void *data)
1993 {
1994         return 1;
1995 }
1996
1997 static ssize_t spi_slave_show(struct device *dev,
1998                               struct device_attribute *attr, char *buf)
1999 {
2000         struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2001                                                    dev);
2002         struct device *child;
2003
2004         child = device_find_child(&ctlr->dev, NULL, match_true);
2005         return sprintf(buf, "%s\n",
2006                        child ? to_spi_device(child)->modalias : NULL);
2007 }
2008
2009 static ssize_t spi_slave_store(struct device *dev,
2010                                struct device_attribute *attr, const char *buf,
2011                                size_t count)
2012 {
2013         struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2014                                                    dev);
2015         struct spi_device *spi;
2016         struct device *child;
2017         char name[32];
2018         int rc;
2019
2020         rc = sscanf(buf, "%31s", name);
2021         if (rc != 1 || !name[0])
2022                 return -EINVAL;
2023
2024         child = device_find_child(&ctlr->dev, NULL, match_true);
2025         if (child) {
2026                 /* Remove registered slave */
2027                 device_unregister(child);
2028                 put_device(child);
2029         }
2030
2031         if (strcmp(name, "(null)")) {
2032                 /* Register new slave */
2033                 spi = spi_alloc_device(ctlr);
2034                 if (!spi)
2035                         return -ENOMEM;
2036
2037                 strlcpy(spi->modalias, name, sizeof(spi->modalias));
2038
2039                 rc = spi_add_device(spi);
2040                 if (rc) {
2041                         spi_dev_put(spi);
2042                         return rc;
2043                 }
2044         }
2045
2046         return count;
2047 }
2048
2049 static DEVICE_ATTR(slave, 0644, spi_slave_show, spi_slave_store);
2050
2051 static struct attribute *spi_slave_attrs[] = {
2052         &dev_attr_slave.attr,
2053         NULL,
2054 };
2055
2056 static const struct attribute_group spi_slave_group = {
2057         .attrs = spi_slave_attrs,
2058 };
2059
2060 static const struct attribute_group *spi_slave_groups[] = {
2061         &spi_controller_statistics_group,
2062         &spi_slave_group,
2063         NULL,
2064 };
2065
2066 static struct class spi_slave_class = {
2067         .name           = "spi_slave",
2068         .owner          = THIS_MODULE,
2069         .dev_release    = spi_controller_release,
2070         .dev_groups     = spi_slave_groups,
2071 };
2072 #else
2073 extern struct class spi_slave_class;    /* dummy */
2074 #endif
2075
2076 /**
2077  * __spi_alloc_controller - allocate an SPI master or slave controller
2078  * @dev: the controller, possibly using the platform_bus
2079  * @size: how much zeroed driver-private data to allocate; the pointer to this
2080  *      memory is in the driver_data field of the returned device,
2081  *      accessible with spi_controller_get_devdata().
2082  * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2083  *      slave (true) controller
2084  * Context: can sleep
2085  *
2086  * This call is used only by SPI controller drivers, which are the
2087  * only ones directly touching chip registers.  It's how they allocate
2088  * an spi_controller structure, prior to calling spi_register_controller().
2089  *
2090  * This must be called from context that can sleep.
2091  *
2092  * The caller is responsible for assigning the bus number and initializing the
2093  * controller's methods before calling spi_register_controller(); and (after
2094  * errors adding the device) calling spi_controller_put() to prevent a memory
2095  * leak.
2096  *
2097  * Return: the SPI controller structure on success, else NULL.
2098  */
2099 struct spi_controller *__spi_alloc_controller(struct device *dev,
2100                                               unsigned int size, bool slave)
2101 {
2102         struct spi_controller   *ctlr;
2103
2104         if (!dev)
2105                 return NULL;
2106
2107         ctlr = kzalloc(size + sizeof(*ctlr), GFP_KERNEL);
2108         if (!ctlr)
2109                 return NULL;
2110
2111         device_initialize(&ctlr->dev);
2112         ctlr->bus_num = -1;
2113         ctlr->num_chipselect = 1;
2114         ctlr->slave = slave;
2115         if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2116                 ctlr->dev.class = &spi_slave_class;
2117         else
2118                 ctlr->dev.class = &spi_master_class;
2119         ctlr->dev.parent = dev;
2120         pm_suspend_ignore_children(&ctlr->dev, true);
2121         spi_controller_set_devdata(ctlr, &ctlr[1]);
2122
2123         return ctlr;
2124 }
2125 EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2126
2127 #ifdef CONFIG_OF
2128 static int of_spi_register_master(struct spi_controller *ctlr)
2129 {
2130         int nb, i, *cs;
2131         struct device_node *np = ctlr->dev.of_node;
2132
2133         if (!np)
2134                 return 0;
2135
2136         nb = of_gpio_named_count(np, "cs-gpios");
2137         ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2138
2139         /* Return error only for an incorrectly formed cs-gpios property */
2140         if (nb == 0 || nb == -ENOENT)
2141                 return 0;
2142         else if (nb < 0)
2143                 return nb;
2144
2145         cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2146                           GFP_KERNEL);
2147         ctlr->cs_gpios = cs;
2148
2149         if (!ctlr->cs_gpios)
2150                 return -ENOMEM;
2151
2152         for (i = 0; i < ctlr->num_chipselect; i++)
2153                 cs[i] = -ENOENT;
2154
2155         for (i = 0; i < nb; i++)
2156                 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2157
2158         return 0;
2159 }
2160 #else
2161 static int of_spi_register_master(struct spi_controller *ctlr)
2162 {
2163         return 0;
2164 }
2165 #endif
2166
2167 /**
2168  * spi_get_gpio_descs() - grab chip select GPIOs for the master
2169  * @ctlr: The SPI master to grab GPIO descriptors for
2170  */
2171 static int spi_get_gpio_descs(struct spi_controller *ctlr)
2172 {
2173         int nb, i;
2174         struct gpio_desc **cs;
2175         struct device *dev = &ctlr->dev;
2176
2177         nb = gpiod_count(dev, "cs");
2178         ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2179
2180         /* No GPIOs at all is fine, else return the error */
2181         if (nb == 0 || nb == -ENOENT)
2182                 return 0;
2183         else if (nb < 0)
2184                 return nb;
2185
2186         cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
2187                           GFP_KERNEL);
2188         if (!cs)
2189                 return -ENOMEM;
2190         ctlr->cs_gpiods = cs;
2191
2192         for (i = 0; i < nb; i++) {
2193                 /*
2194                  * Most chipselects are active low, the inverted
2195                  * semantics are handled by special quirks in gpiolib,
2196                  * so initializing them GPIOD_OUT_LOW here means
2197                  * "unasserted", in most cases this will drive the physical
2198                  * line high.
2199                  */
2200                 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
2201                                                       GPIOD_OUT_LOW);
2202                 if (IS_ERR(cs[i]))
2203                         return PTR_ERR(cs[i]);
2204
2205                 if (cs[i]) {
2206                         /*
2207                          * If we find a CS GPIO, name it after the device and
2208                          * chip select line.
2209                          */
2210                         char *gpioname;
2211
2212                         gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
2213                                                   dev_name(dev), i);
2214                         if (!gpioname)
2215                                 return -ENOMEM;
2216                         gpiod_set_consumer_name(cs[i], gpioname);
2217                 }
2218         }
2219
2220         return 0;
2221 }
2222
2223 static int spi_controller_check_ops(struct spi_controller *ctlr)
2224 {
2225         /*
2226          * The controller may implement only the high-level SPI-memory like
2227          * operations if it does not support regular SPI transfers, and this is
2228          * valid use case.
2229          * If ->mem_ops is NULL, we request that at least one of the
2230          * ->transfer_xxx() method be implemented.
2231          */
2232         if (ctlr->mem_ops) {
2233                 if (!ctlr->mem_ops->exec_op)
2234                         return -EINVAL;
2235         } else if (!ctlr->transfer && !ctlr->transfer_one &&
2236                    !ctlr->transfer_one_message) {
2237                 return -EINVAL;
2238         }
2239
2240         return 0;
2241 }
2242
2243 /**
2244  * spi_register_controller - register SPI master or slave controller
2245  * @ctlr: initialized master, originally from spi_alloc_master() or
2246  *      spi_alloc_slave()
2247  * Context: can sleep
2248  *
2249  * SPI controllers connect to their drivers using some non-SPI bus,
2250  * such as the platform bus.  The final stage of probe() in that code
2251  * includes calling spi_register_controller() to hook up to this SPI bus glue.
2252  *
2253  * SPI controllers use board specific (often SOC specific) bus numbers,
2254  * and board-specific addressing for SPI devices combines those numbers
2255  * with chip select numbers.  Since SPI does not directly support dynamic
2256  * device identification, boards need configuration tables telling which
2257  * chip is at which address.
2258  *
2259  * This must be called from context that can sleep.  It returns zero on
2260  * success, else a negative error code (dropping the controller's refcount).
2261  * After a successful return, the caller is responsible for calling
2262  * spi_unregister_controller().
2263  *
2264  * Return: zero on success, else a negative error code.
2265  */
2266 int spi_register_controller(struct spi_controller *ctlr)
2267 {
2268         struct device           *dev = ctlr->dev.parent;
2269         struct boardinfo        *bi;
2270         int                     status = -ENODEV;
2271         int                     id, first_dynamic;
2272
2273         if (!dev)
2274                 return -ENODEV;
2275
2276         /*
2277          * Make sure all necessary hooks are implemented before registering
2278          * the SPI controller.
2279          */
2280         status = spi_controller_check_ops(ctlr);
2281         if (status)
2282                 return status;
2283
2284         if (!spi_controller_is_slave(ctlr)) {
2285                 if (ctlr->use_gpio_descriptors) {
2286                         status = spi_get_gpio_descs(ctlr);
2287                         if (status)
2288                                 return status;
2289                         /*
2290                          * A controller using GPIO descriptors always
2291                          * supports SPI_CS_HIGH if need be.
2292                          */
2293                         ctlr->mode_bits |= SPI_CS_HIGH;
2294                 } else {
2295                         /* Legacy code path for GPIOs from DT */
2296                         status = of_spi_register_master(ctlr);
2297                         if (status)
2298                                 return status;
2299                 }
2300         }
2301
2302         /* even if it's just one always-selected device, there must
2303          * be at least one chipselect
2304          */
2305         if (ctlr->num_chipselect == 0)
2306                 return -EINVAL;
2307         if (ctlr->bus_num >= 0) {
2308                 /* devices with a fixed bus num must check-in with the num */
2309                 mutex_lock(&board_lock);
2310                 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2311                         ctlr->bus_num + 1, GFP_KERNEL);
2312                 mutex_unlock(&board_lock);
2313                 if (WARN(id < 0, "couldn't get idr"))
2314                         return id == -ENOSPC ? -EBUSY : id;
2315                 ctlr->bus_num = id;
2316         } else if (ctlr->dev.of_node) {
2317                 /* allocate dynamic bus number using Linux idr */
2318                 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2319                 if (id >= 0) {
2320                         ctlr->bus_num = id;
2321                         mutex_lock(&board_lock);
2322                         id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2323                                        ctlr->bus_num + 1, GFP_KERNEL);
2324                         mutex_unlock(&board_lock);
2325                         if (WARN(id < 0, "couldn't get idr"))
2326                                 return id == -ENOSPC ? -EBUSY : id;
2327                 }
2328         }
2329         if (ctlr->bus_num < 0) {
2330                 first_dynamic = of_alias_get_highest_id("spi");
2331                 if (first_dynamic < 0)
2332                         first_dynamic = 0;
2333                 else
2334                         first_dynamic++;
2335
2336                 mutex_lock(&board_lock);
2337                 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2338                                0, GFP_KERNEL);
2339                 mutex_unlock(&board_lock);
2340                 if (WARN(id < 0, "couldn't get idr"))
2341                         return id;
2342                 ctlr->bus_num = id;
2343         }
2344         INIT_LIST_HEAD(&ctlr->queue);
2345         spin_lock_init(&ctlr->queue_lock);
2346         spin_lock_init(&ctlr->bus_lock_spinlock);
2347         mutex_init(&ctlr->bus_lock_mutex);
2348         mutex_init(&ctlr->io_mutex);
2349         ctlr->bus_lock_flag = 0;
2350         init_completion(&ctlr->xfer_completion);
2351         if (!ctlr->max_dma_len)
2352                 ctlr->max_dma_len = INT_MAX;
2353
2354         /* register the device, then userspace will see it.
2355          * registration fails if the bus ID is in use.
2356          */
2357         dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2358         status = device_add(&ctlr->dev);
2359         if (status < 0) {
2360                 /* free bus id */
2361                 mutex_lock(&board_lock);
2362                 idr_remove(&spi_master_idr, ctlr->bus_num);
2363                 mutex_unlock(&board_lock);
2364                 goto done;
2365         }
2366         dev_dbg(dev, "registered %s %s\n",
2367                         spi_controller_is_slave(ctlr) ? "slave" : "master",
2368                         dev_name(&ctlr->dev));
2369
2370         /*
2371          * If we're using a queued driver, start the queue. Note that we don't
2372          * need the queueing logic if the driver is only supporting high-level
2373          * memory operations.
2374          */
2375         if (ctlr->transfer) {
2376                 dev_info(dev, "controller is unqueued, this is deprecated\n");
2377         } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2378                 status = spi_controller_initialize_queue(ctlr);
2379                 if (status) {
2380                         device_del(&ctlr->dev);
2381                         /* free bus id */
2382                         mutex_lock(&board_lock);
2383                         idr_remove(&spi_master_idr, ctlr->bus_num);
2384                         mutex_unlock(&board_lock);
2385                         goto done;
2386                 }
2387         }
2388         /* add statistics */
2389         spin_lock_init(&ctlr->statistics.lock);
2390
2391         mutex_lock(&board_lock);
2392         list_add_tail(&ctlr->list, &spi_controller_list);
2393         list_for_each_entry(bi, &board_list, list)
2394                 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2395         mutex_unlock(&board_lock);
2396
2397         /* Register devices from the device tree and ACPI */
2398         of_register_spi_devices(ctlr);
2399         acpi_register_spi_devices(ctlr);
2400 done:
2401         return status;
2402 }
2403 EXPORT_SYMBOL_GPL(spi_register_controller);
2404
2405 static void devm_spi_unregister(struct device *dev, void *res)
2406 {
2407         spi_unregister_controller(*(struct spi_controller **)res);
2408 }
2409
2410 /**
2411  * devm_spi_register_controller - register managed SPI master or slave
2412  *      controller
2413  * @dev:    device managing SPI controller
2414  * @ctlr: initialized controller, originally from spi_alloc_master() or
2415  *      spi_alloc_slave()
2416  * Context: can sleep
2417  *
2418  * Register a SPI device as with spi_register_controller() which will
2419  * automatically be unregistered and freed.
2420  *
2421  * Return: zero on success, else a negative error code.
2422  */
2423 int devm_spi_register_controller(struct device *dev,
2424                                  struct spi_controller *ctlr)
2425 {
2426         struct spi_controller **ptr;
2427         int ret;
2428
2429         ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2430         if (!ptr)
2431                 return -ENOMEM;
2432
2433         ret = spi_register_controller(ctlr);
2434         if (!ret) {
2435                 *ptr = ctlr;
2436                 devres_add(dev, ptr);
2437         } else {
2438                 devres_free(ptr);
2439         }
2440
2441         return ret;
2442 }
2443 EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2444
2445 static int __unregister(struct device *dev, void *null)
2446 {
2447         spi_unregister_device(to_spi_device(dev));
2448         return 0;
2449 }
2450
2451 /**
2452  * spi_unregister_controller - unregister SPI master or slave controller
2453  * @ctlr: the controller being unregistered
2454  * Context: can sleep
2455  *
2456  * This call is used only by SPI controller drivers, which are the
2457  * only ones directly touching chip registers.
2458  *
2459  * This must be called from context that can sleep.
2460  *
2461  * Note that this function also drops a reference to the controller.
2462  */
2463 void spi_unregister_controller(struct spi_controller *ctlr)
2464 {
2465         struct spi_controller *found;
2466         int id = ctlr->bus_num;
2467         int dummy;
2468
2469         /* First make sure that this controller was ever added */
2470         mutex_lock(&board_lock);
2471         found = idr_find(&spi_master_idr, id);
2472         mutex_unlock(&board_lock);
2473         if (ctlr->queued) {
2474                 if (spi_destroy_queue(ctlr))
2475                         dev_err(&ctlr->dev, "queue remove failed\n");
2476         }
2477         mutex_lock(&board_lock);
2478         list_del(&ctlr->list);
2479         mutex_unlock(&board_lock);
2480
2481         dummy = device_for_each_child(&ctlr->dev, NULL, __unregister);
2482         device_unregister(&ctlr->dev);
2483         /* free bus id */
2484         mutex_lock(&board_lock);
2485         if (found == ctlr)
2486                 idr_remove(&spi_master_idr, id);
2487         mutex_unlock(&board_lock);
2488 }
2489 EXPORT_SYMBOL_GPL(spi_unregister_controller);
2490
2491 int spi_controller_suspend(struct spi_controller *ctlr)
2492 {
2493         int ret;
2494
2495         /* Basically no-ops for non-queued controllers */
2496         if (!ctlr->queued)
2497                 return 0;
2498
2499         ret = spi_stop_queue(ctlr);
2500         if (ret)
2501                 dev_err(&ctlr->dev, "queue stop failed\n");
2502
2503         return ret;
2504 }
2505 EXPORT_SYMBOL_GPL(spi_controller_suspend);
2506
2507 int spi_controller_resume(struct spi_controller *ctlr)
2508 {
2509         int ret;
2510
2511         if (!ctlr->queued)
2512                 return 0;
2513
2514         ret = spi_start_queue(ctlr);
2515         if (ret)
2516                 dev_err(&ctlr->dev, "queue restart failed\n");
2517
2518         return ret;
2519 }
2520 EXPORT_SYMBOL_GPL(spi_controller_resume);
2521
2522 static int __spi_controller_match(struct device *dev, const void *data)
2523 {
2524         struct spi_controller *ctlr;
2525         const u16 *bus_num = data;
2526
2527         ctlr = container_of(dev, struct spi_controller, dev);
2528         return ctlr->bus_num == *bus_num;
2529 }
2530
2531 /**
2532  * spi_busnum_to_master - look up master associated with bus_num
2533  * @bus_num: the master's bus number
2534  * Context: can sleep
2535  *
2536  * This call may be used with devices that are registered after
2537  * arch init time.  It returns a refcounted pointer to the relevant
2538  * spi_controller (which the caller must release), or NULL if there is
2539  * no such master registered.
2540  *
2541  * Return: the SPI master structure on success, else NULL.
2542  */
2543 struct spi_controller *spi_busnum_to_master(u16 bus_num)
2544 {
2545         struct device           *dev;
2546         struct spi_controller   *ctlr = NULL;
2547
2548         dev = class_find_device(&spi_master_class, NULL, &bus_num,
2549                                 __spi_controller_match);
2550         if (dev)
2551                 ctlr = container_of(dev, struct spi_controller, dev);
2552         /* reference got in class_find_device */
2553         return ctlr;
2554 }
2555 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2556
2557 /*-------------------------------------------------------------------------*/
2558
2559 /* Core methods for SPI resource management */
2560
2561 /**
2562  * spi_res_alloc - allocate a spi resource that is life-cycle managed
2563  *                 during the processing of a spi_message while using
2564  *                 spi_transfer_one
2565  * @spi:     the spi device for which we allocate memory
2566  * @release: the release code to execute for this resource
2567  * @size:    size to alloc and return
2568  * @gfp:     GFP allocation flags
2569  *
2570  * Return: the pointer to the allocated data
2571  *
2572  * This may get enhanced in the future to allocate from a memory pool
2573  * of the @spi_device or @spi_controller to avoid repeated allocations.
2574  */
2575 void *spi_res_alloc(struct spi_device *spi,
2576                     spi_res_release_t release,
2577                     size_t size, gfp_t gfp)
2578 {
2579         struct spi_res *sres;
2580
2581         sres = kzalloc(sizeof(*sres) + size, gfp);
2582         if (!sres)
2583                 return NULL;
2584
2585         INIT_LIST_HEAD(&sres->entry);
2586         sres->release = release;
2587
2588         return sres->data;
2589 }
2590 EXPORT_SYMBOL_GPL(spi_res_alloc);
2591
2592 /**
2593  * spi_res_free - free an spi resource
2594  * @res: pointer to the custom data of a resource
2595  *
2596  */
2597 void spi_res_free(void *res)
2598 {
2599         struct spi_res *sres = container_of(res, struct spi_res, data);
2600
2601         if (!res)
2602                 return;
2603
2604         WARN_ON(!list_empty(&sres->entry));
2605         kfree(sres);
2606 }
2607 EXPORT_SYMBOL_GPL(spi_res_free);
2608
2609 /**
2610  * spi_res_add - add a spi_res to the spi_message
2611  * @message: the spi message
2612  * @res:     the spi_resource
2613  */
2614 void spi_res_add(struct spi_message *message, void *res)
2615 {
2616         struct spi_res *sres = container_of(res, struct spi_res, data);
2617
2618         WARN_ON(!list_empty(&sres->entry));
2619         list_add_tail(&sres->entry, &message->resources);
2620 }
2621 EXPORT_SYMBOL_GPL(spi_res_add);
2622
2623 /**
2624  * spi_res_release - release all spi resources for this message
2625  * @ctlr:  the @spi_controller
2626  * @message: the @spi_message
2627  */
2628 void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
2629 {
2630         struct spi_res *res;
2631
2632         while (!list_empty(&message->resources)) {
2633                 res = list_last_entry(&message->resources,
2634                                       struct spi_res, entry);
2635
2636                 if (res->release)
2637                         res->release(ctlr, message, res->data);
2638
2639                 list_del(&res->entry);
2640
2641                 kfree(res);
2642         }
2643 }
2644 EXPORT_SYMBOL_GPL(spi_res_release);
2645
2646 /*-------------------------------------------------------------------------*/
2647
2648 /* Core methods for spi_message alterations */
2649
2650 static void __spi_replace_transfers_release(struct spi_controller *ctlr,
2651                                             struct spi_message *msg,
2652                                             void *res)
2653 {
2654         struct spi_replaced_transfers *rxfer = res;
2655         size_t i;
2656
2657         /* call extra callback if requested */
2658         if (rxfer->release)
2659                 rxfer->release(ctlr, msg, res);
2660
2661         /* insert replaced transfers back into the message */
2662         list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2663
2664         /* remove the formerly inserted entries */
2665         for (i = 0; i < rxfer->inserted; i++)
2666                 list_del(&rxfer->inserted_transfers[i].transfer_list);
2667 }
2668
2669 /**
2670  * spi_replace_transfers - replace transfers with several transfers
2671  *                         and register change with spi_message.resources
2672  * @msg:           the spi_message we work upon
2673  * @xfer_first:    the first spi_transfer we want to replace
2674  * @remove:        number of transfers to remove
2675  * @insert:        the number of transfers we want to insert instead
2676  * @release:       extra release code necessary in some circumstances
2677  * @extradatasize: extra data to allocate (with alignment guarantees
2678  *                 of struct @spi_transfer)
2679  * @gfp:           gfp flags
2680  *
2681  * Returns: pointer to @spi_replaced_transfers,
2682  *          PTR_ERR(...) in case of errors.
2683  */
2684 struct spi_replaced_transfers *spi_replace_transfers(
2685         struct spi_message *msg,
2686         struct spi_transfer *xfer_first,
2687         size_t remove,
2688         size_t insert,
2689         spi_replaced_release_t release,
2690         size_t extradatasize,
2691         gfp_t gfp)
2692 {
2693         struct spi_replaced_transfers *rxfer;
2694         struct spi_transfer *xfer;
2695         size_t i;
2696
2697         /* allocate the structure using spi_res */
2698         rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2699                               insert * sizeof(struct spi_transfer)
2700                               + sizeof(struct spi_replaced_transfers)
2701                               + extradatasize,
2702                               gfp);
2703         if (!rxfer)
2704                 return ERR_PTR(-ENOMEM);
2705
2706         /* the release code to invoke before running the generic release */
2707         rxfer->release = release;
2708
2709         /* assign extradata */
2710         if (extradatasize)
2711                 rxfer->extradata =
2712                         &rxfer->inserted_transfers[insert];
2713
2714         /* init the replaced_transfers list */
2715         INIT_LIST_HEAD(&rxfer->replaced_transfers);
2716
2717         /* assign the list_entry after which we should reinsert
2718          * the @replaced_transfers - it may be spi_message.messages!
2719          */
2720         rxfer->replaced_after = xfer_first->transfer_list.prev;
2721
2722         /* remove the requested number of transfers */
2723         for (i = 0; i < remove; i++) {
2724                 /* if the entry after replaced_after it is msg->transfers
2725                  * then we have been requested to remove more transfers
2726                  * than are in the list
2727                  */
2728                 if (rxfer->replaced_after->next == &msg->transfers) {
2729                         dev_err(&msg->spi->dev,
2730                                 "requested to remove more spi_transfers than are available\n");
2731                         /* insert replaced transfers back into the message */
2732                         list_splice(&rxfer->replaced_transfers,
2733                                     rxfer->replaced_after);
2734
2735                         /* free the spi_replace_transfer structure */
2736                         spi_res_free(rxfer);
2737
2738                         /* and return with an error */
2739                         return ERR_PTR(-EINVAL);
2740                 }
2741
2742                 /* remove the entry after replaced_after from list of
2743                  * transfers and add it to list of replaced_transfers
2744                  */
2745                 list_move_tail(rxfer->replaced_after->next,
2746                                &rxfer->replaced_transfers);
2747         }
2748
2749         /* create copy of the given xfer with identical settings
2750          * based on the first transfer to get removed
2751          */
2752         for (i = 0; i < insert; i++) {
2753                 /* we need to run in reverse order */
2754                 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2755
2756                 /* copy all spi_transfer data */
2757                 memcpy(xfer, xfer_first, sizeof(*xfer));
2758
2759                 /* add to list */
2760                 list_add(&xfer->transfer_list, rxfer->replaced_after);
2761
2762                 /* clear cs_change and delay_usecs for all but the last */
2763                 if (i) {
2764                         xfer->cs_change = false;
2765                         xfer->delay_usecs = 0;
2766                 }
2767         }
2768
2769         /* set up inserted */
2770         rxfer->inserted = insert;
2771
2772         /* and register it with spi_res/spi_message */
2773         spi_res_add(msg, rxfer);
2774
2775         return rxfer;
2776 }
2777 EXPORT_SYMBOL_GPL(spi_replace_transfers);
2778
2779 static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
2780                                         struct spi_message *msg,
2781                                         struct spi_transfer **xferp,
2782                                         size_t maxsize,
2783                                         gfp_t gfp)
2784 {
2785         struct spi_transfer *xfer = *xferp, *xfers;
2786         struct spi_replaced_transfers *srt;
2787         size_t offset;
2788         size_t count, i;
2789
2790         /* warn once about this fact that we are splitting a transfer */
2791         dev_warn_once(&msg->spi->dev,
2792                       "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2793                       xfer->len, maxsize);
2794
2795         /* calculate how many we have to replace */
2796         count = DIV_ROUND_UP(xfer->len, maxsize);
2797
2798         /* create replacement */
2799         srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
2800         if (IS_ERR(srt))
2801                 return PTR_ERR(srt);
2802         xfers = srt->inserted_transfers;
2803
2804         /* now handle each of those newly inserted spi_transfers
2805          * note that the replacements spi_transfers all are preset
2806          * to the same values as *xferp, so tx_buf, rx_buf and len
2807          * are all identical (as well as most others)
2808          * so we just have to fix up len and the pointers.
2809          *
2810          * this also includes support for the depreciated
2811          * spi_message.is_dma_mapped interface
2812          */
2813
2814         /* the first transfer just needs the length modified, so we
2815          * run it outside the loop
2816          */
2817         xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
2818
2819         /* all the others need rx_buf/tx_buf also set */
2820         for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2821                 /* update rx_buf, tx_buf and dma */
2822                 if (xfers[i].rx_buf)
2823                         xfers[i].rx_buf += offset;
2824                 if (xfers[i].rx_dma)
2825                         xfers[i].rx_dma += offset;
2826                 if (xfers[i].tx_buf)
2827                         xfers[i].tx_buf += offset;
2828                 if (xfers[i].tx_dma)
2829                         xfers[i].tx_dma += offset;
2830
2831                 /* update length */
2832                 xfers[i].len = min(maxsize, xfers[i].len - offset);
2833         }
2834
2835         /* we set up xferp to the last entry we have inserted,
2836          * so that we skip those already split transfers
2837          */
2838         *xferp = &xfers[count - 1];
2839
2840         /* increment statistics counters */
2841         SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
2842                                        transfers_split_maxsize);
2843         SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2844                                        transfers_split_maxsize);
2845
2846         return 0;
2847 }
2848
2849 /**
2850  * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2851  *                              when an individual transfer exceeds a
2852  *                              certain size
2853  * @ctlr:    the @spi_controller for this transfer
2854  * @msg:   the @spi_message to transform
2855  * @maxsize:  the maximum when to apply this
2856  * @gfp: GFP allocation flags
2857  *
2858  * Return: status of transformation
2859  */
2860 int spi_split_transfers_maxsize(struct spi_controller *ctlr,
2861                                 struct spi_message *msg,
2862                                 size_t maxsize,
2863                                 gfp_t gfp)
2864 {
2865         struct spi_transfer *xfer;
2866         int ret;
2867
2868         /* iterate over the transfer_list,
2869          * but note that xfer is advanced to the last transfer inserted
2870          * to avoid checking sizes again unnecessarily (also xfer does
2871          * potentiall belong to a different list by the time the
2872          * replacement has happened
2873          */
2874         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2875                 if (xfer->len > maxsize) {
2876                         ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
2877                                                            maxsize, gfp);
2878                         if (ret)
2879                                 return ret;
2880                 }
2881         }
2882
2883         return 0;
2884 }
2885 EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2886
2887 /*-------------------------------------------------------------------------*/
2888
2889 /* Core methods for SPI controller protocol drivers.  Some of the
2890  * other core methods are currently defined as inline functions.
2891  */
2892
2893 static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
2894                                         u8 bits_per_word)
2895 {
2896         if (ctlr->bits_per_word_mask) {
2897                 /* Only 32 bits fit in the mask */
2898                 if (bits_per_word > 32)
2899                         return -EINVAL;
2900                 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
2901                         return -EINVAL;
2902         }
2903
2904         return 0;
2905 }
2906
2907 /**
2908  * spi_setup - setup SPI mode and clock rate
2909  * @spi: the device whose settings are being modified
2910  * Context: can sleep, and no requests are queued to the device
2911  *
2912  * SPI protocol drivers may need to update the transfer mode if the
2913  * device doesn't work with its default.  They may likewise need
2914  * to update clock rates or word sizes from initial values.  This function
2915  * changes those settings, and must be called from a context that can sleep.
2916  * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2917  * effect the next time the device is selected and data is transferred to
2918  * or from it.  When this function returns, the spi device is deselected.
2919  *
2920  * Note that this call will fail if the protocol driver specifies an option
2921  * that the underlying controller or its driver does not support.  For
2922  * example, not all hardware supports wire transfers using nine bit words,
2923  * LSB-first wire encoding, or active-high chipselects.
2924  *
2925  * Return: zero on success, else a negative error code.
2926  */
2927 int spi_setup(struct spi_device *spi)
2928 {
2929         unsigned        bad_bits, ugly_bits;
2930         int             status;
2931
2932         /* check mode to prevent that DUAL and QUAD set at the same time
2933          */
2934         if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2935                 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2936                 dev_err(&spi->dev,
2937                 "setup: can not select dual and quad at the same time\n");
2938                 return -EINVAL;
2939         }
2940         /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2941          */
2942         if ((spi->mode & SPI_3WIRE) && (spi->mode &
2943                 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
2944                  SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
2945                 return -EINVAL;
2946         /* help drivers fail *cleanly* when they need options
2947          * that aren't supported with their current controller
2948          * SPI_CS_WORD has a fallback software implementation,
2949          * so it is ignored here.
2950          */
2951         bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
2952         ugly_bits = bad_bits &
2953                     (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
2954                      SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
2955         if (ugly_bits) {
2956                 dev_warn(&spi->dev,
2957                          "setup: ignoring unsupported mode bits %x\n",
2958                          ugly_bits);
2959                 spi->mode &= ~ugly_bits;
2960                 bad_bits &= ~ugly_bits;
2961         }
2962         if (bad_bits) {
2963                 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
2964                         bad_bits);
2965                 return -EINVAL;
2966         }
2967
2968         if (!spi->bits_per_word)
2969                 spi->bits_per_word = 8;
2970
2971         status = __spi_validate_bits_per_word(spi->controller,
2972                                               spi->bits_per_word);
2973         if (status)
2974                 return status;
2975
2976         if (!spi->max_speed_hz)
2977                 spi->max_speed_hz = spi->controller->max_speed_hz;
2978
2979         if (spi->controller->setup)
2980                 status = spi->controller->setup(spi);
2981
2982         spi_set_cs(spi, false);
2983
2984         dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2985                         (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2986                         (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2987                         (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2988                         (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2989                         (spi->mode & SPI_LOOP) ? "loopback, " : "",
2990                         spi->bits_per_word, spi->max_speed_hz,
2991                         status);
2992
2993         return status;
2994 }
2995 EXPORT_SYMBOL_GPL(spi_setup);
2996
2997 static int __spi_validate(struct spi_device *spi, struct spi_message *message)
2998 {
2999         struct spi_controller *ctlr = spi->controller;
3000         struct spi_transfer *xfer;
3001         int w_size;
3002
3003         if (list_empty(&message->transfers))
3004                 return -EINVAL;
3005
3006         /* If an SPI controller does not support toggling the CS line on each
3007          * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3008          * for the CS line, we can emulate the CS-per-word hardware function by
3009          * splitting transfers into one-word transfers and ensuring that
3010          * cs_change is set for each transfer.
3011          */
3012         if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
3013                                           spi->cs_gpiod ||
3014                                           gpio_is_valid(spi->cs_gpio))) {
3015                 size_t maxsize;
3016                 int ret;
3017
3018                 maxsize = (spi->bits_per_word + 7) / 8;
3019
3020                 /* spi_split_transfers_maxsize() requires message->spi */
3021                 message->spi = spi;
3022
3023                 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
3024                                                   GFP_KERNEL);
3025                 if (ret)
3026                         return ret;
3027
3028                 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3029                         /* don't change cs_change on the last entry in the list */
3030                         if (list_is_last(&xfer->transfer_list, &message->transfers))
3031                                 break;
3032                         xfer->cs_change = 1;
3033                 }
3034         }
3035
3036         /* Half-duplex links include original MicroWire, and ones with
3037          * only one data pin like SPI_3WIRE (switches direction) or where
3038          * either MOSI or MISO is missing.  They can also be caused by
3039          * software limitations.
3040          */
3041         if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
3042             (spi->mode & SPI_3WIRE)) {
3043                 unsigned flags = ctlr->flags;
3044
3045                 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3046                         if (xfer->rx_buf && xfer->tx_buf)
3047                                 return -EINVAL;
3048                         if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
3049                                 return -EINVAL;
3050                         if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
3051                                 return -EINVAL;
3052                 }
3053         }
3054
3055         /**
3056          * Set transfer bits_per_word and max speed as spi device default if
3057          * it is not set for this transfer.
3058          * Set transfer tx_nbits and rx_nbits as single transfer default
3059          * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3060          * Ensure transfer word_delay is at least as long as that required by
3061          * device itself.
3062          */
3063         message->frame_length = 0;
3064         list_for_each_entry(xfer, &message->transfers, transfer_list) {
3065                 message->frame_length += xfer->len;
3066                 if (!xfer->bits_per_word)
3067                         xfer->bits_per_word = spi->bits_per_word;
3068
3069                 if (!xfer->speed_hz)
3070                         xfer->speed_hz = spi->max_speed_hz;
3071                 if (!xfer->speed_hz)
3072                         xfer->speed_hz = ctlr->max_speed_hz;
3073
3074                 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
3075                         xfer->speed_hz = ctlr->max_speed_hz;
3076
3077                 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
3078                         return -EINVAL;
3079
3080                 /*
3081                  * SPI transfer length should be multiple of SPI word size
3082                  * where SPI word size should be power-of-two multiple
3083                  */
3084                 if (xfer->bits_per_word <= 8)
3085                         w_size = 1;
3086                 else if (xfer->bits_per_word <= 16)
3087                         w_size = 2;
3088                 else
3089                         w_size = 4;
3090
3091                 /* No partial transfers accepted */
3092                 if (xfer->len % w_size)
3093                         return -EINVAL;
3094
3095                 if (xfer->speed_hz && ctlr->min_speed_hz &&
3096                     xfer->speed_hz < ctlr->min_speed_hz)
3097                         return -EINVAL;
3098
3099                 if (xfer->tx_buf && !xfer->tx_nbits)
3100                         xfer->tx_nbits = SPI_NBITS_SINGLE;
3101                 if (xfer->rx_buf && !xfer->rx_nbits)
3102                         xfer->rx_nbits = SPI_NBITS_SINGLE;
3103                 /* check transfer tx/rx_nbits:
3104                  * 1. check the value matches one of single, dual and quad
3105                  * 2. check tx/rx_nbits match the mode in spi_device
3106                  */
3107                 if (xfer->tx_buf) {
3108                         if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3109                                 xfer->tx_nbits != SPI_NBITS_DUAL &&
3110                                 xfer->tx_nbits != SPI_NBITS_QUAD)
3111                                 return -EINVAL;
3112                         if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3113                                 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3114                                 return -EINVAL;
3115                         if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3116                                 !(spi->mode & SPI_TX_QUAD))
3117                                 return -EINVAL;
3118                 }
3119                 /* check transfer rx_nbits */
3120                 if (xfer->rx_buf) {
3121                         if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3122                                 xfer->rx_nbits != SPI_NBITS_DUAL &&
3123                                 xfer->rx_nbits != SPI_NBITS_QUAD)
3124                                 return -EINVAL;
3125                         if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3126                                 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3127                                 return -EINVAL;
3128                         if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3129                                 !(spi->mode & SPI_RX_QUAD))
3130                                 return -EINVAL;
3131                 }
3132
3133                 if (xfer->word_delay_usecs < spi->word_delay_usecs)
3134                         xfer->word_delay_usecs = spi->word_delay_usecs;
3135         }
3136
3137         message->status = -EINPROGRESS;
3138
3139         return 0;
3140 }
3141
3142 static int __spi_async(struct spi_device *spi, struct spi_message *message)
3143 {
3144         struct spi_controller *ctlr = spi->controller;
3145
3146         /*
3147          * Some controllers do not support doing regular SPI transfers. Return
3148          * ENOTSUPP when this is the case.
3149          */
3150         if (!ctlr->transfer)
3151                 return -ENOTSUPP;
3152
3153         message->spi = spi;
3154
3155         SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
3156         SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3157
3158         trace_spi_message_submit(message);
3159
3160         return ctlr->transfer(spi, message);
3161 }
3162
3163 /**
3164  * spi_async - asynchronous SPI transfer
3165  * @spi: device with which data will be exchanged
3166  * @message: describes the data transfers, including completion callback
3167  * Context: any (irqs may be blocked, etc)
3168  *
3169  * This call may be used in_irq and other contexts which can't sleep,
3170  * as well as from task contexts which can sleep.
3171  *
3172  * The completion callback is invoked in a context which can't sleep.
3173  * Before that invocation, the value of message->status is undefined.
3174  * When the callback is issued, message->status holds either zero (to
3175  * indicate complete success) or a negative error code.  After that
3176  * callback returns, the driver which issued the transfer request may
3177  * deallocate the associated memory; it's no longer in use by any SPI
3178  * core or controller driver code.
3179  *
3180  * Note that although all messages to a spi_device are handled in
3181  * FIFO order, messages may go to different devices in other orders.
3182  * Some device might be higher priority, or have various "hard" access
3183  * time requirements, for example.
3184  *
3185  * On detection of any fault during the transfer, processing of
3186  * the entire message is aborted, and the device is deselected.
3187  * Until returning from the associated message completion callback,
3188  * no other spi_message queued to that device will be processed.
3189  * (This rule applies equally to all the synchronous transfer calls,
3190  * which are wrappers around this core asynchronous primitive.)
3191  *
3192  * Return: zero on success, else a negative error code.
3193  */
3194 int spi_async(struct spi_device *spi, struct spi_message *message)
3195 {
3196         struct spi_controller *ctlr = spi->controller;
3197         int ret;
3198         unsigned long flags;
3199
3200         ret = __spi_validate(spi, message);
3201         if (ret != 0)
3202                 return ret;
3203
3204         spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3205
3206         if (ctlr->bus_lock_flag)
3207                 ret = -EBUSY;
3208         else
3209                 ret = __spi_async(spi, message);
3210
3211         spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3212
3213         return ret;
3214 }
3215 EXPORT_SYMBOL_GPL(spi_async);
3216
3217 /**
3218  * spi_async_locked - version of spi_async with exclusive bus usage
3219  * @spi: device with which data will be exchanged
3220  * @message: describes the data transfers, including completion callback
3221  * Context: any (irqs may be blocked, etc)
3222  *
3223  * This call may be used in_irq and other contexts which can't sleep,
3224  * as well as from task contexts which can sleep.
3225  *
3226  * The completion callback is invoked in a context which can't sleep.
3227  * Before that invocation, the value of message->status is undefined.
3228  * When the callback is issued, message->status holds either zero (to
3229  * indicate complete success) or a negative error code.  After that
3230  * callback returns, the driver which issued the transfer request may
3231  * deallocate the associated memory; it's no longer in use by any SPI
3232  * core or controller driver code.
3233  *
3234  * Note that although all messages to a spi_device are handled in
3235  * FIFO order, messages may go to different devices in other orders.
3236  * Some device might be higher priority, or have various "hard" access
3237  * time requirements, for example.
3238  *
3239  * On detection of any fault during the transfer, processing of
3240  * the entire message is aborted, and the device is deselected.
3241  * Until returning from the associated message completion callback,
3242  * no other spi_message queued to that device will be processed.
3243  * (This rule applies equally to all the synchronous transfer calls,
3244  * which are wrappers around this core asynchronous primitive.)
3245  *
3246  * Return: zero on success, else a negative error code.
3247  */
3248 int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3249 {
3250         struct spi_controller *ctlr = spi->controller;
3251         int ret;
3252         unsigned long flags;
3253
3254         ret = __spi_validate(spi, message);
3255         if (ret != 0)
3256                 return ret;
3257
3258         spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3259
3260         ret = __spi_async(spi, message);
3261
3262         spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3263
3264         return ret;
3265
3266 }
3267 EXPORT_SYMBOL_GPL(spi_async_locked);
3268
3269 /*-------------------------------------------------------------------------*/
3270
3271 /* Utility methods for SPI protocol drivers, layered on
3272  * top of the core.  Some other utility methods are defined as
3273  * inline functions.
3274  */
3275
3276 static void spi_complete(void *arg)
3277 {
3278         complete(arg);
3279 }
3280
3281 static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3282 {
3283         DECLARE_COMPLETION_ONSTACK(done);
3284         int status;
3285         struct spi_controller *ctlr = spi->controller;
3286         unsigned long flags;
3287
3288         status = __spi_validate(spi, message);
3289         if (status != 0)
3290                 return status;
3291
3292         message->complete = spi_complete;