Commit | Line | Data |
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8ae12a0d | 1 | /* |
ca632f55 | 2 | * SPI init/core code |
8ae12a0d DB |
3 | * |
4 | * Copyright (C) 2005 David Brownell | |
d57a4282 | 5 | * Copyright (C) 2008 Secret Lab Technologies Ltd. |
8ae12a0d DB |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
8ae12a0d DB |
16 | */ |
17 | ||
8ae12a0d DB |
18 | #include <linux/kernel.h> |
19 | #include <linux/device.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/cache.h> | |
99adef31 MB |
22 | #include <linux/dma-mapping.h> |
23 | #include <linux/dmaengine.h> | |
94040828 | 24 | #include <linux/mutex.h> |
2b7a32f7 | 25 | #include <linux/of_device.h> |
d57a4282 | 26 | #include <linux/of_irq.h> |
86be408b | 27 | #include <linux/clk/clk-conf.h> |
5a0e3ad6 | 28 | #include <linux/slab.h> |
e0626e38 | 29 | #include <linux/mod_devicetable.h> |
8ae12a0d | 30 | #include <linux/spi/spi.h> |
74317984 | 31 | #include <linux/of_gpio.h> |
3ae22e8c | 32 | #include <linux/pm_runtime.h> |
f48c767c | 33 | #include <linux/pm_domain.h> |
025ed130 | 34 | #include <linux/export.h> |
8bd75c77 | 35 | #include <linux/sched/rt.h> |
ffbbdd21 LW |
36 | #include <linux/delay.h> |
37 | #include <linux/kthread.h> | |
64bee4d2 MW |
38 | #include <linux/ioport.h> |
39 | #include <linux/acpi.h> | |
8ae12a0d | 40 | |
56ec1978 MB |
41 | #define CREATE_TRACE_POINTS |
42 | #include <trace/events/spi.h> | |
43 | ||
8ae12a0d DB |
44 | static void spidev_release(struct device *dev) |
45 | { | |
0ffa0285 | 46 | struct spi_device *spi = to_spi_device(dev); |
8ae12a0d DB |
47 | |
48 | /* spi masters may cleanup for released devices */ | |
49 | if (spi->master->cleanup) | |
50 | spi->master->cleanup(spi); | |
51 | ||
0c868461 | 52 | spi_master_put(spi->master); |
07a389fe | 53 | kfree(spi); |
8ae12a0d DB |
54 | } |
55 | ||
56 | static ssize_t | |
57 | modalias_show(struct device *dev, struct device_attribute *a, char *buf) | |
58 | { | |
59 | const struct spi_device *spi = to_spi_device(dev); | |
8c4ff6d0 ZR |
60 | int len; |
61 | ||
62 | len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); | |
63 | if (len != -ENODEV) | |
64 | return len; | |
8ae12a0d | 65 | |
d8e328b3 | 66 | return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); |
8ae12a0d | 67 | } |
aa7da564 | 68 | static DEVICE_ATTR_RO(modalias); |
8ae12a0d | 69 | |
eca2ebc7 MS |
70 | #define SPI_STATISTICS_ATTRS(field, file) \ |
71 | static ssize_t spi_master_##field##_show(struct device *dev, \ | |
72 | struct device_attribute *attr, \ | |
73 | char *buf) \ | |
74 | { \ | |
75 | struct spi_master *master = container_of(dev, \ | |
76 | struct spi_master, dev); \ | |
77 | return spi_statistics_##field##_show(&master->statistics, buf); \ | |
78 | } \ | |
79 | static struct device_attribute dev_attr_spi_master_##field = { \ | |
80 | .attr = { .name = file, .mode = S_IRUGO }, \ | |
81 | .show = spi_master_##field##_show, \ | |
82 | }; \ | |
83 | static ssize_t spi_device_##field##_show(struct device *dev, \ | |
84 | struct device_attribute *attr, \ | |
85 | char *buf) \ | |
86 | { \ | |
d1eba93b | 87 | struct spi_device *spi = to_spi_device(dev); \ |
eca2ebc7 MS |
88 | return spi_statistics_##field##_show(&spi->statistics, buf); \ |
89 | } \ | |
90 | static struct device_attribute dev_attr_spi_device_##field = { \ | |
91 | .attr = { .name = file, .mode = S_IRUGO }, \ | |
92 | .show = spi_device_##field##_show, \ | |
93 | } | |
94 | ||
95 | #define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \ | |
96 | static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \ | |
97 | char *buf) \ | |
98 | { \ | |
99 | unsigned long flags; \ | |
100 | ssize_t len; \ | |
101 | spin_lock_irqsave(&stat->lock, flags); \ | |
102 | len = sprintf(buf, format_string, stat->field); \ | |
103 | spin_unlock_irqrestore(&stat->lock, flags); \ | |
104 | return len; \ | |
105 | } \ | |
106 | SPI_STATISTICS_ATTRS(name, file) | |
107 | ||
108 | #define SPI_STATISTICS_SHOW(field, format_string) \ | |
109 | SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \ | |
110 | field, format_string) | |
111 | ||
112 | SPI_STATISTICS_SHOW(messages, "%lu"); | |
113 | SPI_STATISTICS_SHOW(transfers, "%lu"); | |
114 | SPI_STATISTICS_SHOW(errors, "%lu"); | |
115 | SPI_STATISTICS_SHOW(timedout, "%lu"); | |
116 | ||
117 | SPI_STATISTICS_SHOW(spi_sync, "%lu"); | |
118 | SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu"); | |
119 | SPI_STATISTICS_SHOW(spi_async, "%lu"); | |
120 | ||
121 | SPI_STATISTICS_SHOW(bytes, "%llu"); | |
122 | SPI_STATISTICS_SHOW(bytes_rx, "%llu"); | |
123 | SPI_STATISTICS_SHOW(bytes_tx, "%llu"); | |
124 | ||
6b7bc061 MS |
125 | #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \ |
126 | SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \ | |
127 | "transfer_bytes_histo_" number, \ | |
128 | transfer_bytes_histo[index], "%lu") | |
129 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1"); | |
130 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3"); | |
131 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7"); | |
132 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15"); | |
133 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31"); | |
134 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63"); | |
135 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127"); | |
136 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255"); | |
137 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511"); | |
138 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023"); | |
139 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047"); | |
140 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095"); | |
141 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191"); | |
142 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383"); | |
143 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767"); | |
144 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535"); | |
145 | SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+"); | |
146 | ||
aa7da564 GKH |
147 | static struct attribute *spi_dev_attrs[] = { |
148 | &dev_attr_modalias.attr, | |
149 | NULL, | |
8ae12a0d | 150 | }; |
eca2ebc7 MS |
151 | |
152 | static const struct attribute_group spi_dev_group = { | |
153 | .attrs = spi_dev_attrs, | |
154 | }; | |
155 | ||
156 | static struct attribute *spi_device_statistics_attrs[] = { | |
157 | &dev_attr_spi_device_messages.attr, | |
158 | &dev_attr_spi_device_transfers.attr, | |
159 | &dev_attr_spi_device_errors.attr, | |
160 | &dev_attr_spi_device_timedout.attr, | |
161 | &dev_attr_spi_device_spi_sync.attr, | |
162 | &dev_attr_spi_device_spi_sync_immediate.attr, | |
163 | &dev_attr_spi_device_spi_async.attr, | |
164 | &dev_attr_spi_device_bytes.attr, | |
165 | &dev_attr_spi_device_bytes_rx.attr, | |
166 | &dev_attr_spi_device_bytes_tx.attr, | |
6b7bc061 MS |
167 | &dev_attr_spi_device_transfer_bytes_histo0.attr, |
168 | &dev_attr_spi_device_transfer_bytes_histo1.attr, | |
169 | &dev_attr_spi_device_transfer_bytes_histo2.attr, | |
170 | &dev_attr_spi_device_transfer_bytes_histo3.attr, | |
171 | &dev_attr_spi_device_transfer_bytes_histo4.attr, | |
172 | &dev_attr_spi_device_transfer_bytes_histo5.attr, | |
173 | &dev_attr_spi_device_transfer_bytes_histo6.attr, | |
174 | &dev_attr_spi_device_transfer_bytes_histo7.attr, | |
175 | &dev_attr_spi_device_transfer_bytes_histo8.attr, | |
176 | &dev_attr_spi_device_transfer_bytes_histo9.attr, | |
177 | &dev_attr_spi_device_transfer_bytes_histo10.attr, | |
178 | &dev_attr_spi_device_transfer_bytes_histo11.attr, | |
179 | &dev_attr_spi_device_transfer_bytes_histo12.attr, | |
180 | &dev_attr_spi_device_transfer_bytes_histo13.attr, | |
181 | &dev_attr_spi_device_transfer_bytes_histo14.attr, | |
182 | &dev_attr_spi_device_transfer_bytes_histo15.attr, | |
183 | &dev_attr_spi_device_transfer_bytes_histo16.attr, | |
eca2ebc7 MS |
184 | NULL, |
185 | }; | |
186 | ||
187 | static const struct attribute_group spi_device_statistics_group = { | |
188 | .name = "statistics", | |
189 | .attrs = spi_device_statistics_attrs, | |
190 | }; | |
191 | ||
192 | static const struct attribute_group *spi_dev_groups[] = { | |
193 | &spi_dev_group, | |
194 | &spi_device_statistics_group, | |
195 | NULL, | |
196 | }; | |
197 | ||
198 | static struct attribute *spi_master_statistics_attrs[] = { | |
199 | &dev_attr_spi_master_messages.attr, | |
200 | &dev_attr_spi_master_transfers.attr, | |
201 | &dev_attr_spi_master_errors.attr, | |
202 | &dev_attr_spi_master_timedout.attr, | |
203 | &dev_attr_spi_master_spi_sync.attr, | |
204 | &dev_attr_spi_master_spi_sync_immediate.attr, | |
205 | &dev_attr_spi_master_spi_async.attr, | |
206 | &dev_attr_spi_master_bytes.attr, | |
207 | &dev_attr_spi_master_bytes_rx.attr, | |
208 | &dev_attr_spi_master_bytes_tx.attr, | |
6b7bc061 MS |
209 | &dev_attr_spi_master_transfer_bytes_histo0.attr, |
210 | &dev_attr_spi_master_transfer_bytes_histo1.attr, | |
211 | &dev_attr_spi_master_transfer_bytes_histo2.attr, | |
212 | &dev_attr_spi_master_transfer_bytes_histo3.attr, | |
213 | &dev_attr_spi_master_transfer_bytes_histo4.attr, | |
214 | &dev_attr_spi_master_transfer_bytes_histo5.attr, | |
215 | &dev_attr_spi_master_transfer_bytes_histo6.attr, | |
216 | &dev_attr_spi_master_transfer_bytes_histo7.attr, | |
217 | &dev_attr_spi_master_transfer_bytes_histo8.attr, | |
218 | &dev_attr_spi_master_transfer_bytes_histo9.attr, | |
219 | &dev_attr_spi_master_transfer_bytes_histo10.attr, | |
220 | &dev_attr_spi_master_transfer_bytes_histo11.attr, | |
221 | &dev_attr_spi_master_transfer_bytes_histo12.attr, | |
222 | &dev_attr_spi_master_transfer_bytes_histo13.attr, | |
223 | &dev_attr_spi_master_transfer_bytes_histo14.attr, | |
224 | &dev_attr_spi_master_transfer_bytes_histo15.attr, | |
225 | &dev_attr_spi_master_transfer_bytes_histo16.attr, | |
eca2ebc7 MS |
226 | NULL, |
227 | }; | |
228 | ||
229 | static const struct attribute_group spi_master_statistics_group = { | |
230 | .name = "statistics", | |
231 | .attrs = spi_master_statistics_attrs, | |
232 | }; | |
233 | ||
234 | static const struct attribute_group *spi_master_groups[] = { | |
235 | &spi_master_statistics_group, | |
236 | NULL, | |
237 | }; | |
238 | ||
239 | void spi_statistics_add_transfer_stats(struct spi_statistics *stats, | |
240 | struct spi_transfer *xfer, | |
241 | struct spi_master *master) | |
242 | { | |
243 | unsigned long flags; | |
6b7bc061 MS |
244 | int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1; |
245 | ||
246 | if (l2len < 0) | |
247 | l2len = 0; | |
eca2ebc7 MS |
248 | |
249 | spin_lock_irqsave(&stats->lock, flags); | |
250 | ||
251 | stats->transfers++; | |
6b7bc061 | 252 | stats->transfer_bytes_histo[l2len]++; |
eca2ebc7 MS |
253 | |
254 | stats->bytes += xfer->len; | |
255 | if ((xfer->tx_buf) && | |
256 | (xfer->tx_buf != master->dummy_tx)) | |
257 | stats->bytes_tx += xfer->len; | |
258 | if ((xfer->rx_buf) && | |
259 | (xfer->rx_buf != master->dummy_rx)) | |
260 | stats->bytes_rx += xfer->len; | |
261 | ||
262 | spin_unlock_irqrestore(&stats->lock, flags); | |
263 | } | |
264 | EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats); | |
8ae12a0d DB |
265 | |
266 | /* modalias support makes "modprobe $MODALIAS" new-style hotplug work, | |
267 | * and the sysfs version makes coldplug work too. | |
268 | */ | |
269 | ||
75368bf6 AV |
270 | static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, |
271 | const struct spi_device *sdev) | |
272 | { | |
273 | while (id->name[0]) { | |
274 | if (!strcmp(sdev->modalias, id->name)) | |
275 | return id; | |
276 | id++; | |
277 | } | |
278 | return NULL; | |
279 | } | |
280 | ||
281 | const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) | |
282 | { | |
283 | const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); | |
284 | ||
285 | return spi_match_id(sdrv->id_table, sdev); | |
286 | } | |
287 | EXPORT_SYMBOL_GPL(spi_get_device_id); | |
288 | ||
8ae12a0d DB |
289 | static int spi_match_device(struct device *dev, struct device_driver *drv) |
290 | { | |
291 | const struct spi_device *spi = to_spi_device(dev); | |
75368bf6 AV |
292 | const struct spi_driver *sdrv = to_spi_driver(drv); |
293 | ||
2b7a32f7 SA |
294 | /* Attempt an OF style match */ |
295 | if (of_driver_match_device(dev, drv)) | |
296 | return 1; | |
297 | ||
64bee4d2 MW |
298 | /* Then try ACPI */ |
299 | if (acpi_driver_match_device(dev, drv)) | |
300 | return 1; | |
301 | ||
75368bf6 AV |
302 | if (sdrv->id_table) |
303 | return !!spi_match_id(sdrv->id_table, spi); | |
8ae12a0d | 304 | |
35f74fca | 305 | return strcmp(spi->modalias, drv->name) == 0; |
8ae12a0d DB |
306 | } |
307 | ||
7eff2e7a | 308 | static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) |
8ae12a0d DB |
309 | { |
310 | const struct spi_device *spi = to_spi_device(dev); | |
8c4ff6d0 ZR |
311 | int rc; |
312 | ||
313 | rc = acpi_device_uevent_modalias(dev, env); | |
314 | if (rc != -ENODEV) | |
315 | return rc; | |
8ae12a0d | 316 | |
e0626e38 | 317 | add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); |
8ae12a0d DB |
318 | return 0; |
319 | } | |
320 | ||
8ae12a0d DB |
321 | struct bus_type spi_bus_type = { |
322 | .name = "spi", | |
aa7da564 | 323 | .dev_groups = spi_dev_groups, |
8ae12a0d DB |
324 | .match = spi_match_device, |
325 | .uevent = spi_uevent, | |
8ae12a0d DB |
326 | }; |
327 | EXPORT_SYMBOL_GPL(spi_bus_type); | |
328 | ||
b885244e DB |
329 | |
330 | static int spi_drv_probe(struct device *dev) | |
331 | { | |
332 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
44af7927 | 333 | struct spi_device *spi = to_spi_device(dev); |
33cf00e5 MW |
334 | int ret; |
335 | ||
86be408b SN |
336 | ret = of_clk_set_defaults(dev->of_node, false); |
337 | if (ret) | |
338 | return ret; | |
339 | ||
44af7927 JH |
340 | if (dev->of_node) { |
341 | spi->irq = of_irq_get(dev->of_node, 0); | |
342 | if (spi->irq == -EPROBE_DEFER) | |
343 | return -EPROBE_DEFER; | |
344 | if (spi->irq < 0) | |
345 | spi->irq = 0; | |
346 | } | |
347 | ||
676e7c25 UH |
348 | ret = dev_pm_domain_attach(dev, true); |
349 | if (ret != -EPROBE_DEFER) { | |
44af7927 | 350 | ret = sdrv->probe(spi); |
676e7c25 UH |
351 | if (ret) |
352 | dev_pm_domain_detach(dev, true); | |
353 | } | |
b885244e | 354 | |
33cf00e5 | 355 | return ret; |
b885244e DB |
356 | } |
357 | ||
358 | static int spi_drv_remove(struct device *dev) | |
359 | { | |
360 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
33cf00e5 MW |
361 | int ret; |
362 | ||
aec35f4e | 363 | ret = sdrv->remove(to_spi_device(dev)); |
676e7c25 | 364 | dev_pm_domain_detach(dev, true); |
b885244e | 365 | |
33cf00e5 | 366 | return ret; |
b885244e DB |
367 | } |
368 | ||
369 | static void spi_drv_shutdown(struct device *dev) | |
370 | { | |
371 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
372 | ||
373 | sdrv->shutdown(to_spi_device(dev)); | |
374 | } | |
375 | ||
33e34dc6 | 376 | /** |
ca5d2485 | 377 | * __spi_register_driver - register a SPI driver |
88c9321d | 378 | * @owner: owner module of the driver to register |
33e34dc6 DB |
379 | * @sdrv: the driver to register |
380 | * Context: can sleep | |
97d56dc6 JMC |
381 | * |
382 | * Return: zero on success, else a negative error code. | |
33e34dc6 | 383 | */ |
ca5d2485 | 384 | int __spi_register_driver(struct module *owner, struct spi_driver *sdrv) |
b885244e | 385 | { |
ca5d2485 | 386 | sdrv->driver.owner = owner; |
b885244e DB |
387 | sdrv->driver.bus = &spi_bus_type; |
388 | if (sdrv->probe) | |
389 | sdrv->driver.probe = spi_drv_probe; | |
390 | if (sdrv->remove) | |
391 | sdrv->driver.remove = spi_drv_remove; | |
392 | if (sdrv->shutdown) | |
393 | sdrv->driver.shutdown = spi_drv_shutdown; | |
394 | return driver_register(&sdrv->driver); | |
395 | } | |
ca5d2485 | 396 | EXPORT_SYMBOL_GPL(__spi_register_driver); |
b885244e | 397 | |
8ae12a0d DB |
398 | /*-------------------------------------------------------------------------*/ |
399 | ||
400 | /* SPI devices should normally not be created by SPI device drivers; that | |
401 | * would make them board-specific. Similarly with SPI master drivers. | |
402 | * Device registration normally goes into like arch/.../mach.../board-YYY.c | |
403 | * with other readonly (flashable) information about mainboard devices. | |
404 | */ | |
405 | ||
406 | struct boardinfo { | |
407 | struct list_head list; | |
2b9603a0 | 408 | struct spi_board_info board_info; |
8ae12a0d DB |
409 | }; |
410 | ||
411 | static LIST_HEAD(board_list); | |
2b9603a0 FT |
412 | static LIST_HEAD(spi_master_list); |
413 | ||
414 | /* | |
415 | * Used to protect add/del opertion for board_info list and | |
416 | * spi_master list, and their matching process | |
417 | */ | |
94040828 | 418 | static DEFINE_MUTEX(board_lock); |
8ae12a0d | 419 | |
dc87c98e GL |
420 | /** |
421 | * spi_alloc_device - Allocate a new SPI device | |
422 | * @master: Controller to which device is connected | |
423 | * Context: can sleep | |
424 | * | |
425 | * Allows a driver to allocate and initialize a spi_device without | |
426 | * registering it immediately. This allows a driver to directly | |
427 | * fill the spi_device with device parameters before calling | |
428 | * spi_add_device() on it. | |
429 | * | |
430 | * Caller is responsible to call spi_add_device() on the returned | |
431 | * spi_device structure to add it to the SPI master. If the caller | |
432 | * needs to discard the spi_device without adding it, then it should | |
433 | * call spi_dev_put() on it. | |
434 | * | |
97d56dc6 | 435 | * Return: a pointer to the new device, or NULL. |
dc87c98e GL |
436 | */ |
437 | struct spi_device *spi_alloc_device(struct spi_master *master) | |
438 | { | |
439 | struct spi_device *spi; | |
dc87c98e GL |
440 | |
441 | if (!spi_master_get(master)) | |
442 | return NULL; | |
443 | ||
5fe5f05e | 444 | spi = kzalloc(sizeof(*spi), GFP_KERNEL); |
dc87c98e | 445 | if (!spi) { |
dc87c98e GL |
446 | spi_master_put(master); |
447 | return NULL; | |
448 | } | |
449 | ||
450 | spi->master = master; | |
178db7d3 | 451 | spi->dev.parent = &master->dev; |
dc87c98e GL |
452 | spi->dev.bus = &spi_bus_type; |
453 | spi->dev.release = spidev_release; | |
446411e1 | 454 | spi->cs_gpio = -ENOENT; |
eca2ebc7 MS |
455 | |
456 | spin_lock_init(&spi->statistics.lock); | |
457 | ||
dc87c98e GL |
458 | device_initialize(&spi->dev); |
459 | return spi; | |
460 | } | |
461 | EXPORT_SYMBOL_GPL(spi_alloc_device); | |
462 | ||
e13ac47b JN |
463 | static void spi_dev_set_name(struct spi_device *spi) |
464 | { | |
465 | struct acpi_device *adev = ACPI_COMPANION(&spi->dev); | |
466 | ||
467 | if (adev) { | |
468 | dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev)); | |
469 | return; | |
470 | } | |
471 | ||
472 | dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev), | |
473 | spi->chip_select); | |
474 | } | |
475 | ||
b6fb8d3a MW |
476 | static int spi_dev_check(struct device *dev, void *data) |
477 | { | |
478 | struct spi_device *spi = to_spi_device(dev); | |
479 | struct spi_device *new_spi = data; | |
480 | ||
481 | if (spi->master == new_spi->master && | |
482 | spi->chip_select == new_spi->chip_select) | |
483 | return -EBUSY; | |
484 | return 0; | |
485 | } | |
486 | ||
dc87c98e GL |
487 | /** |
488 | * spi_add_device - Add spi_device allocated with spi_alloc_device | |
489 | * @spi: spi_device to register | |
490 | * | |
491 | * Companion function to spi_alloc_device. Devices allocated with | |
492 | * spi_alloc_device can be added onto the spi bus with this function. | |
493 | * | |
97d56dc6 | 494 | * Return: 0 on success; negative errno on failure |
dc87c98e GL |
495 | */ |
496 | int spi_add_device(struct spi_device *spi) | |
497 | { | |
e48880e0 | 498 | static DEFINE_MUTEX(spi_add_lock); |
74317984 JCPV |
499 | struct spi_master *master = spi->master; |
500 | struct device *dev = master->dev.parent; | |
dc87c98e GL |
501 | int status; |
502 | ||
503 | /* Chipselects are numbered 0..max; validate. */ | |
74317984 | 504 | if (spi->chip_select >= master->num_chipselect) { |
dc87c98e GL |
505 | dev_err(dev, "cs%d >= max %d\n", |
506 | spi->chip_select, | |
74317984 | 507 | master->num_chipselect); |
dc87c98e GL |
508 | return -EINVAL; |
509 | } | |
510 | ||
511 | /* Set the bus ID string */ | |
e13ac47b | 512 | spi_dev_set_name(spi); |
e48880e0 DB |
513 | |
514 | /* We need to make sure there's no other device with this | |
515 | * chipselect **BEFORE** we call setup(), else we'll trash | |
516 | * its configuration. Lock against concurrent add() calls. | |
517 | */ | |
518 | mutex_lock(&spi_add_lock); | |
519 | ||
b6fb8d3a MW |
520 | status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); |
521 | if (status) { | |
e48880e0 DB |
522 | dev_err(dev, "chipselect %d already in use\n", |
523 | spi->chip_select); | |
e48880e0 DB |
524 | goto done; |
525 | } | |
526 | ||
74317984 JCPV |
527 | if (master->cs_gpios) |
528 | spi->cs_gpio = master->cs_gpios[spi->chip_select]; | |
529 | ||
e48880e0 DB |
530 | /* Drivers may modify this initial i/o setup, but will |
531 | * normally rely on the device being setup. Devices | |
532 | * using SPI_CS_HIGH can't coexist well otherwise... | |
533 | */ | |
7d077197 | 534 | status = spi_setup(spi); |
dc87c98e | 535 | if (status < 0) { |
eb288a1f LW |
536 | dev_err(dev, "can't setup %s, status %d\n", |
537 | dev_name(&spi->dev), status); | |
e48880e0 | 538 | goto done; |
dc87c98e GL |
539 | } |
540 | ||
e48880e0 | 541 | /* Device may be bound to an active driver when this returns */ |
dc87c98e | 542 | status = device_add(&spi->dev); |
e48880e0 | 543 | if (status < 0) |
eb288a1f LW |
544 | dev_err(dev, "can't add %s, status %d\n", |
545 | dev_name(&spi->dev), status); | |
e48880e0 | 546 | else |
35f74fca | 547 | dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); |
dc87c98e | 548 | |
e48880e0 DB |
549 | done: |
550 | mutex_unlock(&spi_add_lock); | |
551 | return status; | |
dc87c98e GL |
552 | } |
553 | EXPORT_SYMBOL_GPL(spi_add_device); | |
8ae12a0d | 554 | |
33e34dc6 DB |
555 | /** |
556 | * spi_new_device - instantiate one new SPI device | |
557 | * @master: Controller to which device is connected | |
558 | * @chip: Describes the SPI device | |
559 | * Context: can sleep | |
560 | * | |
561 | * On typical mainboards, this is purely internal; and it's not needed | |
8ae12a0d DB |
562 | * after board init creates the hard-wired devices. Some development |
563 | * platforms may not be able to use spi_register_board_info though, and | |
564 | * this is exported so that for example a USB or parport based adapter | |
565 | * driver could add devices (which it would learn about out-of-band). | |
082c8cb4 | 566 | * |
97d56dc6 | 567 | * Return: the new device, or NULL. |
8ae12a0d | 568 | */ |
e9d5a461 AB |
569 | struct spi_device *spi_new_device(struct spi_master *master, |
570 | struct spi_board_info *chip) | |
8ae12a0d DB |
571 | { |
572 | struct spi_device *proxy; | |
8ae12a0d DB |
573 | int status; |
574 | ||
082c8cb4 DB |
575 | /* NOTE: caller did any chip->bus_num checks necessary. |
576 | * | |
577 | * Also, unless we change the return value convention to use | |
578 | * error-or-pointer (not NULL-or-pointer), troubleshootability | |
579 | * suggests syslogged diagnostics are best here (ugh). | |
580 | */ | |
581 | ||
dc87c98e GL |
582 | proxy = spi_alloc_device(master); |
583 | if (!proxy) | |
8ae12a0d DB |
584 | return NULL; |
585 | ||
102eb975 GL |
586 | WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); |
587 | ||
8ae12a0d DB |
588 | proxy->chip_select = chip->chip_select; |
589 | proxy->max_speed_hz = chip->max_speed_hz; | |
980a01c9 | 590 | proxy->mode = chip->mode; |
8ae12a0d | 591 | proxy->irq = chip->irq; |
102eb975 | 592 | strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); |
8ae12a0d DB |
593 | proxy->dev.platform_data = (void *) chip->platform_data; |
594 | proxy->controller_data = chip->controller_data; | |
595 | proxy->controller_state = NULL; | |
8ae12a0d | 596 | |
dc87c98e | 597 | status = spi_add_device(proxy); |
8ae12a0d | 598 | if (status < 0) { |
dc87c98e GL |
599 | spi_dev_put(proxy); |
600 | return NULL; | |
8ae12a0d DB |
601 | } |
602 | ||
8ae12a0d DB |
603 | return proxy; |
604 | } | |
605 | EXPORT_SYMBOL_GPL(spi_new_device); | |
606 | ||
3b1884c2 GU |
607 | /** |
608 | * spi_unregister_device - unregister a single SPI device | |
609 | * @spi: spi_device to unregister | |
610 | * | |
611 | * Start making the passed SPI device vanish. Normally this would be handled | |
612 | * by spi_unregister_master(). | |
613 | */ | |
614 | void spi_unregister_device(struct spi_device *spi) | |
615 | { | |
bd6c1644 GU |
616 | if (!spi) |
617 | return; | |
618 | ||
619 | if (spi->dev.of_node) | |
620 | of_node_clear_flag(spi->dev.of_node, OF_POPULATED); | |
621 | device_unregister(&spi->dev); | |
3b1884c2 GU |
622 | } |
623 | EXPORT_SYMBOL_GPL(spi_unregister_device); | |
624 | ||
2b9603a0 FT |
625 | static void spi_match_master_to_boardinfo(struct spi_master *master, |
626 | struct spi_board_info *bi) | |
627 | { | |
628 | struct spi_device *dev; | |
629 | ||
630 | if (master->bus_num != bi->bus_num) | |
631 | return; | |
632 | ||
633 | dev = spi_new_device(master, bi); | |
634 | if (!dev) | |
635 | dev_err(master->dev.parent, "can't create new device for %s\n", | |
636 | bi->modalias); | |
637 | } | |
638 | ||
33e34dc6 DB |
639 | /** |
640 | * spi_register_board_info - register SPI devices for a given board | |
641 | * @info: array of chip descriptors | |
642 | * @n: how many descriptors are provided | |
643 | * Context: can sleep | |
644 | * | |
8ae12a0d DB |
645 | * Board-specific early init code calls this (probably during arch_initcall) |
646 | * with segments of the SPI device table. Any device nodes are created later, | |
647 | * after the relevant parent SPI controller (bus_num) is defined. We keep | |
648 | * this table of devices forever, so that reloading a controller driver will | |
649 | * not make Linux forget about these hard-wired devices. | |
650 | * | |
651 | * Other code can also call this, e.g. a particular add-on board might provide | |
652 | * SPI devices through its expansion connector, so code initializing that board | |
653 | * would naturally declare its SPI devices. | |
654 | * | |
655 | * The board info passed can safely be __initdata ... but be careful of | |
656 | * any embedded pointers (platform_data, etc), they're copied as-is. | |
97d56dc6 JMC |
657 | * |
658 | * Return: zero on success, else a negative error code. | |
8ae12a0d | 659 | */ |
fd4a319b | 660 | int spi_register_board_info(struct spi_board_info const *info, unsigned n) |
8ae12a0d | 661 | { |
2b9603a0 FT |
662 | struct boardinfo *bi; |
663 | int i; | |
8ae12a0d | 664 | |
c7908a37 XL |
665 | if (!n) |
666 | return -EINVAL; | |
667 | ||
2b9603a0 | 668 | bi = kzalloc(n * sizeof(*bi), GFP_KERNEL); |
8ae12a0d DB |
669 | if (!bi) |
670 | return -ENOMEM; | |
8ae12a0d | 671 | |
2b9603a0 FT |
672 | for (i = 0; i < n; i++, bi++, info++) { |
673 | struct spi_master *master; | |
8ae12a0d | 674 | |
2b9603a0 FT |
675 | memcpy(&bi->board_info, info, sizeof(*info)); |
676 | mutex_lock(&board_lock); | |
677 | list_add_tail(&bi->list, &board_list); | |
678 | list_for_each_entry(master, &spi_master_list, list) | |
679 | spi_match_master_to_boardinfo(master, &bi->board_info); | |
680 | mutex_unlock(&board_lock); | |
8ae12a0d | 681 | } |
2b9603a0 FT |
682 | |
683 | return 0; | |
8ae12a0d DB |
684 | } |
685 | ||
686 | /*-------------------------------------------------------------------------*/ | |
687 | ||
b158935f MB |
688 | static void spi_set_cs(struct spi_device *spi, bool enable) |
689 | { | |
690 | if (spi->mode & SPI_CS_HIGH) | |
691 | enable = !enable; | |
692 | ||
243f07be | 693 | if (gpio_is_valid(spi->cs_gpio)) |
b158935f MB |
694 | gpio_set_value(spi->cs_gpio, !enable); |
695 | else if (spi->master->set_cs) | |
696 | spi->master->set_cs(spi, !enable); | |
697 | } | |
698 | ||
2de440f5 | 699 | #ifdef CONFIG_HAS_DMA |
6ad45a27 MB |
700 | static int spi_map_buf(struct spi_master *master, struct device *dev, |
701 | struct sg_table *sgt, void *buf, size_t len, | |
702 | enum dma_data_direction dir) | |
703 | { | |
704 | const bool vmalloced_buf = is_vmalloc_addr(buf); | |
65598c13 AG |
705 | int desc_len; |
706 | int sgs; | |
6ad45a27 MB |
707 | struct page *vm_page; |
708 | void *sg_buf; | |
709 | size_t min; | |
710 | int i, ret; | |
711 | ||
65598c13 AG |
712 | if (vmalloced_buf) { |
713 | desc_len = PAGE_SIZE; | |
714 | sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len); | |
715 | } else { | |
716 | desc_len = master->max_dma_len; | |
717 | sgs = DIV_ROUND_UP(len, desc_len); | |
718 | } | |
719 | ||
6ad45a27 MB |
720 | ret = sg_alloc_table(sgt, sgs, GFP_KERNEL); |
721 | if (ret != 0) | |
722 | return ret; | |
723 | ||
724 | for (i = 0; i < sgs; i++) { | |
6ad45a27 MB |
725 | |
726 | if (vmalloced_buf) { | |
65598c13 AG |
727 | min = min_t(size_t, |
728 | len, desc_len - offset_in_page(buf)); | |
6ad45a27 MB |
729 | vm_page = vmalloc_to_page(buf); |
730 | if (!vm_page) { | |
731 | sg_free_table(sgt); | |
732 | return -ENOMEM; | |
733 | } | |
c1aefbdd CK |
734 | sg_set_page(&sgt->sgl[i], vm_page, |
735 | min, offset_in_page(buf)); | |
6ad45a27 | 736 | } else { |
65598c13 | 737 | min = min_t(size_t, len, desc_len); |
6ad45a27 | 738 | sg_buf = buf; |
c1aefbdd | 739 | sg_set_buf(&sgt->sgl[i], sg_buf, min); |
6ad45a27 MB |
740 | } |
741 | ||
6ad45a27 MB |
742 | |
743 | buf += min; | |
744 | len -= min; | |
745 | } | |
746 | ||
747 | ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir); | |
89e4b66a GU |
748 | if (!ret) |
749 | ret = -ENOMEM; | |
6ad45a27 MB |
750 | if (ret < 0) { |
751 | sg_free_table(sgt); | |
752 | return ret; | |
753 | } | |
754 | ||
755 | sgt->nents = ret; | |
756 | ||
757 | return 0; | |
758 | } | |
759 | ||
760 | static void spi_unmap_buf(struct spi_master *master, struct device *dev, | |
761 | struct sg_table *sgt, enum dma_data_direction dir) | |
762 | { | |
763 | if (sgt->orig_nents) { | |
764 | dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir); | |
765 | sg_free_table(sgt); | |
766 | } | |
767 | } | |
768 | ||
2de440f5 | 769 | static int __spi_map_msg(struct spi_master *master, struct spi_message *msg) |
99adef31 | 770 | { |
99adef31 MB |
771 | struct device *tx_dev, *rx_dev; |
772 | struct spi_transfer *xfer; | |
6ad45a27 | 773 | int ret; |
3a2eba9b | 774 | |
6ad45a27 | 775 | if (!master->can_dma) |
99adef31 MB |
776 | return 0; |
777 | ||
c37f45b5 LL |
778 | if (master->dma_tx) |
779 | tx_dev = master->dma_tx->device->dev; | |
780 | else | |
781 | tx_dev = &master->dev; | |
782 | ||
783 | if (master->dma_rx) | |
784 | rx_dev = master->dma_rx->device->dev; | |
785 | else | |
786 | rx_dev = &master->dev; | |
99adef31 MB |
787 | |
788 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
789 | if (!master->can_dma(master, msg->spi, xfer)) | |
790 | continue; | |
791 | ||
792 | if (xfer->tx_buf != NULL) { | |
6ad45a27 MB |
793 | ret = spi_map_buf(master, tx_dev, &xfer->tx_sg, |
794 | (void *)xfer->tx_buf, xfer->len, | |
795 | DMA_TO_DEVICE); | |
796 | if (ret != 0) | |
797 | return ret; | |
99adef31 MB |
798 | } |
799 | ||
800 | if (xfer->rx_buf != NULL) { | |
6ad45a27 MB |
801 | ret = spi_map_buf(master, rx_dev, &xfer->rx_sg, |
802 | xfer->rx_buf, xfer->len, | |
803 | DMA_FROM_DEVICE); | |
804 | if (ret != 0) { | |
805 | spi_unmap_buf(master, tx_dev, &xfer->tx_sg, | |
806 | DMA_TO_DEVICE); | |
807 | return ret; | |
99adef31 MB |
808 | } |
809 | } | |
810 | } | |
811 | ||
812 | master->cur_msg_mapped = true; | |
813 | ||
814 | return 0; | |
815 | } | |
816 | ||
4b786458 | 817 | static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg) |
99adef31 MB |
818 | { |
819 | struct spi_transfer *xfer; | |
820 | struct device *tx_dev, *rx_dev; | |
821 | ||
6ad45a27 | 822 | if (!master->cur_msg_mapped || !master->can_dma) |
99adef31 MB |
823 | return 0; |
824 | ||
c37f45b5 LL |
825 | if (master->dma_tx) |
826 | tx_dev = master->dma_tx->device->dev; | |
827 | else | |
828 | tx_dev = &master->dev; | |
829 | ||
830 | if (master->dma_rx) | |
831 | rx_dev = master->dma_rx->device->dev; | |
832 | else | |
833 | rx_dev = &master->dev; | |
99adef31 MB |
834 | |
835 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
836 | if (!master->can_dma(master, msg->spi, xfer)) | |
837 | continue; | |
838 | ||
6ad45a27 MB |
839 | spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); |
840 | spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); | |
99adef31 MB |
841 | } |
842 | ||
843 | return 0; | |
844 | } | |
2de440f5 GU |
845 | #else /* !CONFIG_HAS_DMA */ |
846 | static inline int __spi_map_msg(struct spi_master *master, | |
847 | struct spi_message *msg) | |
848 | { | |
849 | return 0; | |
850 | } | |
851 | ||
4b786458 MS |
852 | static inline int __spi_unmap_msg(struct spi_master *master, |
853 | struct spi_message *msg) | |
2de440f5 GU |
854 | { |
855 | return 0; | |
856 | } | |
857 | #endif /* !CONFIG_HAS_DMA */ | |
858 | ||
4b786458 MS |
859 | static inline int spi_unmap_msg(struct spi_master *master, |
860 | struct spi_message *msg) | |
861 | { | |
862 | struct spi_transfer *xfer; | |
863 | ||
864 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
865 | /* | |
866 | * Restore the original value of tx_buf or rx_buf if they are | |
867 | * NULL. | |
868 | */ | |
869 | if (xfer->tx_buf == master->dummy_tx) | |
870 | xfer->tx_buf = NULL; | |
871 | if (xfer->rx_buf == master->dummy_rx) | |
872 | xfer->rx_buf = NULL; | |
873 | } | |
874 | ||
875 | return __spi_unmap_msg(master, msg); | |
876 | } | |
877 | ||
2de440f5 GU |
878 | static int spi_map_msg(struct spi_master *master, struct spi_message *msg) |
879 | { | |
880 | struct spi_transfer *xfer; | |
881 | void *tmp; | |
882 | unsigned int max_tx, max_rx; | |
883 | ||
884 | if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) { | |
885 | max_tx = 0; | |
886 | max_rx = 0; | |
887 | ||
888 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
889 | if ((master->flags & SPI_MASTER_MUST_TX) && | |
890 | !xfer->tx_buf) | |
891 | max_tx = max(xfer->len, max_tx); | |
892 | if ((master->flags & SPI_MASTER_MUST_RX) && | |
893 | !xfer->rx_buf) | |
894 | max_rx = max(xfer->len, max_rx); | |
895 | } | |
896 | ||
897 | if (max_tx) { | |
898 | tmp = krealloc(master->dummy_tx, max_tx, | |
899 | GFP_KERNEL | GFP_DMA); | |
900 | if (!tmp) | |
901 | return -ENOMEM; | |
902 | master->dummy_tx = tmp; | |
903 | memset(tmp, 0, max_tx); | |
904 | } | |
905 | ||
906 | if (max_rx) { | |
907 | tmp = krealloc(master->dummy_rx, max_rx, | |
908 | GFP_KERNEL | GFP_DMA); | |
909 | if (!tmp) | |
910 | return -ENOMEM; | |
911 | master->dummy_rx = tmp; | |
912 | } | |
913 | ||
914 | if (max_tx || max_rx) { | |
915 | list_for_each_entry(xfer, &msg->transfers, | |
916 | transfer_list) { | |
917 | if (!xfer->tx_buf) | |
918 | xfer->tx_buf = master->dummy_tx; | |
919 | if (!xfer->rx_buf) | |
920 | xfer->rx_buf = master->dummy_rx; | |
921 | } | |
922 | } | |
923 | } | |
924 | ||
925 | return __spi_map_msg(master, msg); | |
926 | } | |
99adef31 | 927 | |
b158935f MB |
928 | /* |
929 | * spi_transfer_one_message - Default implementation of transfer_one_message() | |
930 | * | |
931 | * This is a standard implementation of transfer_one_message() for | |
932 | * drivers which impelment a transfer_one() operation. It provides | |
933 | * standard handling of delays and chip select management. | |
934 | */ | |
935 | static int spi_transfer_one_message(struct spi_master *master, | |
936 | struct spi_message *msg) | |
937 | { | |
938 | struct spi_transfer *xfer; | |
b158935f MB |
939 | bool keep_cs = false; |
940 | int ret = 0; | |
682a71b2 | 941 | unsigned long ms = 1; |
eca2ebc7 MS |
942 | struct spi_statistics *statm = &master->statistics; |
943 | struct spi_statistics *stats = &msg->spi->statistics; | |
b158935f MB |
944 | |
945 | spi_set_cs(msg->spi, true); | |
946 | ||
eca2ebc7 MS |
947 | SPI_STATISTICS_INCREMENT_FIELD(statm, messages); |
948 | SPI_STATISTICS_INCREMENT_FIELD(stats, messages); | |
949 | ||
b158935f MB |
950 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
951 | trace_spi_transfer_start(msg, xfer); | |
952 | ||
eca2ebc7 MS |
953 | spi_statistics_add_transfer_stats(statm, xfer, master); |
954 | spi_statistics_add_transfer_stats(stats, xfer, master); | |
955 | ||
38ec10f6 MB |
956 | if (xfer->tx_buf || xfer->rx_buf) { |
957 | reinit_completion(&master->xfer_completion); | |
b158935f | 958 | |
38ec10f6 MB |
959 | ret = master->transfer_one(master, msg->spi, xfer); |
960 | if (ret < 0) { | |
eca2ebc7 MS |
961 | SPI_STATISTICS_INCREMENT_FIELD(statm, |
962 | errors); | |
963 | SPI_STATISTICS_INCREMENT_FIELD(stats, | |
964 | errors); | |
38ec10f6 MB |
965 | dev_err(&msg->spi->dev, |
966 | "SPI transfer failed: %d\n", ret); | |
967 | goto out; | |
968 | } | |
b158935f | 969 | |
38ec10f6 MB |
970 | if (ret > 0) { |
971 | ret = 0; | |
972 | ms = xfer->len * 8 * 1000 / xfer->speed_hz; | |
973 | ms += ms + 100; /* some tolerance */ | |
16a0ce4e | 974 | |
38ec10f6 MB |
975 | ms = wait_for_completion_timeout(&master->xfer_completion, |
976 | msecs_to_jiffies(ms)); | |
977 | } | |
16a0ce4e | 978 | |
38ec10f6 | 979 | if (ms == 0) { |
eca2ebc7 MS |
980 | SPI_STATISTICS_INCREMENT_FIELD(statm, |
981 | timedout); | |
982 | SPI_STATISTICS_INCREMENT_FIELD(stats, | |
983 | timedout); | |
38ec10f6 MB |
984 | dev_err(&msg->spi->dev, |
985 | "SPI transfer timed out\n"); | |
986 | msg->status = -ETIMEDOUT; | |
987 | } | |
988 | } else { | |
989 | if (xfer->len) | |
990 | dev_err(&msg->spi->dev, | |
991 | "Bufferless transfer has length %u\n", | |
992 | xfer->len); | |
13a42798 | 993 | } |
b158935f MB |
994 | |
995 | trace_spi_transfer_stop(msg, xfer); | |
996 | ||
997 | if (msg->status != -EINPROGRESS) | |
998 | goto out; | |
999 | ||
1000 | if (xfer->delay_usecs) | |
1001 | udelay(xfer->delay_usecs); | |
1002 | ||
1003 | if (xfer->cs_change) { | |
1004 | if (list_is_last(&xfer->transfer_list, | |
1005 | &msg->transfers)) { | |
1006 | keep_cs = true; | |
1007 | } else { | |
0b73aa63 MB |
1008 | spi_set_cs(msg->spi, false); |
1009 | udelay(10); | |
1010 | spi_set_cs(msg->spi, true); | |
b158935f MB |
1011 | } |
1012 | } | |
1013 | ||
1014 | msg->actual_length += xfer->len; | |
1015 | } | |
1016 | ||
1017 | out: | |
1018 | if (ret != 0 || !keep_cs) | |
1019 | spi_set_cs(msg->spi, false); | |
1020 | ||
1021 | if (msg->status == -EINPROGRESS) | |
1022 | msg->status = ret; | |
1023 | ||
ff61eb42 | 1024 | if (msg->status && master->handle_err) |
b716c4ff AS |
1025 | master->handle_err(master, msg); |
1026 | ||
b158935f MB |
1027 | spi_finalize_current_message(master); |
1028 | ||
1029 | return ret; | |
1030 | } | |
1031 | ||
1032 | /** | |
1033 | * spi_finalize_current_transfer - report completion of a transfer | |
2c675689 | 1034 | * @master: the master reporting completion |
b158935f MB |
1035 | * |
1036 | * Called by SPI drivers using the core transfer_one_message() | |
1037 | * implementation to notify it that the current interrupt driven | |
9e8f4882 | 1038 | * transfer has finished and the next one may be scheduled. |
b158935f MB |
1039 | */ |
1040 | void spi_finalize_current_transfer(struct spi_master *master) | |
1041 | { | |
1042 | complete(&master->xfer_completion); | |
1043 | } | |
1044 | EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); | |
1045 | ||
ffbbdd21 | 1046 | /** |
fc9e0f71 MB |
1047 | * __spi_pump_messages - function which processes spi message queue |
1048 | * @master: master to process queue for | |
1049 | * @in_kthread: true if we are in the context of the message pump thread | |
ffbbdd21 LW |
1050 | * |
1051 | * This function checks if there is any spi message in the queue that | |
1052 | * needs processing and if so call out to the driver to initialize hardware | |
1053 | * and transfer each message. | |
1054 | * | |
0461a414 MB |
1055 | * Note that it is called both from the kthread itself and also from |
1056 | * inside spi_sync(); the queue extraction handling at the top of the | |
1057 | * function should deal with this safely. | |
ffbbdd21 | 1058 | */ |
fc9e0f71 | 1059 | static void __spi_pump_messages(struct spi_master *master, bool in_kthread) |
ffbbdd21 | 1060 | { |
ffbbdd21 LW |
1061 | unsigned long flags; |
1062 | bool was_busy = false; | |
1063 | int ret; | |
1064 | ||
983aee5d | 1065 | /* Lock queue */ |
ffbbdd21 | 1066 | spin_lock_irqsave(&master->queue_lock, flags); |
983aee5d MB |
1067 | |
1068 | /* Make sure we are not already running a message */ | |
1069 | if (master->cur_msg) { | |
1070 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1071 | return; | |
1072 | } | |
1073 | ||
0461a414 MB |
1074 | /* If another context is idling the device then defer */ |
1075 | if (master->idling) { | |
1076 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
1077 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1078 | return; | |
1079 | } | |
1080 | ||
983aee5d | 1081 | /* Check if the queue is idle */ |
ffbbdd21 | 1082 | if (list_empty(&master->queue) || !master->running) { |
b0b36b86 BF |
1083 | if (!master->busy) { |
1084 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1085 | return; | |
ffbbdd21 | 1086 | } |
fc9e0f71 MB |
1087 | |
1088 | /* Only do teardown in the thread */ | |
1089 | if (!in_kthread) { | |
1090 | queue_kthread_work(&master->kworker, | |
1091 | &master->pump_messages); | |
1092 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1093 | return; | |
1094 | } | |
1095 | ||
ffbbdd21 | 1096 | master->busy = false; |
0461a414 | 1097 | master->idling = true; |
ffbbdd21 | 1098 | spin_unlock_irqrestore(&master->queue_lock, flags); |
0461a414 | 1099 | |
3a2eba9b MB |
1100 | kfree(master->dummy_rx); |
1101 | master->dummy_rx = NULL; | |
1102 | kfree(master->dummy_tx); | |
1103 | master->dummy_tx = NULL; | |
b0b36b86 BF |
1104 | if (master->unprepare_transfer_hardware && |
1105 | master->unprepare_transfer_hardware(master)) | |
1106 | dev_err(&master->dev, | |
1107 | "failed to unprepare transfer hardware\n"); | |
49834de2 MB |
1108 | if (master->auto_runtime_pm) { |
1109 | pm_runtime_mark_last_busy(master->dev.parent); | |
1110 | pm_runtime_put_autosuspend(master->dev.parent); | |
1111 | } | |
56ec1978 | 1112 | trace_spi_master_idle(master); |
ffbbdd21 | 1113 | |
0461a414 MB |
1114 | spin_lock_irqsave(&master->queue_lock, flags); |
1115 | master->idling = false; | |
ffbbdd21 LW |
1116 | spin_unlock_irqrestore(&master->queue_lock, flags); |
1117 | return; | |
1118 | } | |
ffbbdd21 | 1119 | |
ffbbdd21 LW |
1120 | /* Extract head of queue */ |
1121 | master->cur_msg = | |
a89e2d27 | 1122 | list_first_entry(&master->queue, struct spi_message, queue); |
ffbbdd21 LW |
1123 | |
1124 | list_del_init(&master->cur_msg->queue); | |
1125 | if (master->busy) | |
1126 | was_busy = true; | |
1127 | else | |
1128 | master->busy = true; | |
1129 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1130 | ||
49834de2 MB |
1131 | if (!was_busy && master->auto_runtime_pm) { |
1132 | ret = pm_runtime_get_sync(master->dev.parent); | |
1133 | if (ret < 0) { | |
1134 | dev_err(&master->dev, "Failed to power device: %d\n", | |
1135 | ret); | |
1136 | return; | |
1137 | } | |
1138 | } | |
1139 | ||
56ec1978 MB |
1140 | if (!was_busy) |
1141 | trace_spi_master_busy(master); | |
1142 | ||
7dfd2bd7 | 1143 | if (!was_busy && master->prepare_transfer_hardware) { |
ffbbdd21 LW |
1144 | ret = master->prepare_transfer_hardware(master); |
1145 | if (ret) { | |
1146 | dev_err(&master->dev, | |
1147 | "failed to prepare transfer hardware\n"); | |
49834de2 MB |
1148 | |
1149 | if (master->auto_runtime_pm) | |
1150 | pm_runtime_put(master->dev.parent); | |
ffbbdd21 LW |
1151 | return; |
1152 | } | |
1153 | } | |
1154 | ||
56ec1978 MB |
1155 | trace_spi_message_start(master->cur_msg); |
1156 | ||
2841a5fc MB |
1157 | if (master->prepare_message) { |
1158 | ret = master->prepare_message(master, master->cur_msg); | |
1159 | if (ret) { | |
1160 | dev_err(&master->dev, | |
1161 | "failed to prepare message: %d\n", ret); | |
1162 | master->cur_msg->status = ret; | |
1163 | spi_finalize_current_message(master); | |
1164 | return; | |
1165 | } | |
1166 | master->cur_msg_prepared = true; | |
1167 | } | |
1168 | ||
99adef31 MB |
1169 | ret = spi_map_msg(master, master->cur_msg); |
1170 | if (ret) { | |
1171 | master->cur_msg->status = ret; | |
1172 | spi_finalize_current_message(master); | |
1173 | return; | |
1174 | } | |
1175 | ||
ffbbdd21 LW |
1176 | ret = master->transfer_one_message(master, master->cur_msg); |
1177 | if (ret) { | |
1178 | dev_err(&master->dev, | |
1f802f82 | 1179 | "failed to transfer one message from queue\n"); |
ffbbdd21 LW |
1180 | return; |
1181 | } | |
1182 | } | |
1183 | ||
fc9e0f71 MB |
1184 | /** |
1185 | * spi_pump_messages - kthread work function which processes spi message queue | |
1186 | * @work: pointer to kthread work struct contained in the master struct | |
1187 | */ | |
1188 | static void spi_pump_messages(struct kthread_work *work) | |
1189 | { | |
1190 | struct spi_master *master = | |
1191 | container_of(work, struct spi_master, pump_messages); | |
1192 | ||
1193 | __spi_pump_messages(master, true); | |
1194 | } | |
1195 | ||
ffbbdd21 LW |
1196 | static int spi_init_queue(struct spi_master *master) |
1197 | { | |
1198 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
1199 | ||
ffbbdd21 LW |
1200 | master->running = false; |
1201 | master->busy = false; | |
1202 | ||
1203 | init_kthread_worker(&master->kworker); | |
1204 | master->kworker_task = kthread_run(kthread_worker_fn, | |
f170168b | 1205 | &master->kworker, "%s", |
ffbbdd21 LW |
1206 | dev_name(&master->dev)); |
1207 | if (IS_ERR(master->kworker_task)) { | |
1208 | dev_err(&master->dev, "failed to create message pump task\n"); | |
98a8f5a0 | 1209 | return PTR_ERR(master->kworker_task); |
ffbbdd21 LW |
1210 | } |
1211 | init_kthread_work(&master->pump_messages, spi_pump_messages); | |
1212 | ||
1213 | /* | |
1214 | * Master config will indicate if this controller should run the | |
1215 | * message pump with high (realtime) priority to reduce the transfer | |
1216 | * latency on the bus by minimising the delay between a transfer | |
1217 | * request and the scheduling of the message pump thread. Without this | |
1218 | * setting the message pump thread will remain at default priority. | |
1219 | */ | |
1220 | if (master->rt) { | |
1221 | dev_info(&master->dev, | |
1222 | "will run message pump with realtime priority\n"); | |
1223 | sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m); | |
1224 | } | |
1225 | ||
1226 | return 0; | |
1227 | } | |
1228 | ||
1229 | /** | |
1230 | * spi_get_next_queued_message() - called by driver to check for queued | |
1231 | * messages | |
1232 | * @master: the master to check for queued messages | |
1233 | * | |
1234 | * If there are more messages in the queue, the next message is returned from | |
1235 | * this call. | |
97d56dc6 JMC |
1236 | * |
1237 | * Return: the next message in the queue, else NULL if the queue is empty. | |
ffbbdd21 LW |
1238 | */ |
1239 | struct spi_message *spi_get_next_queued_message(struct spi_master *master) | |
1240 | { | |
1241 | struct spi_message *next; | |
1242 | unsigned long flags; | |
1243 | ||
1244 | /* get a pointer to the next message, if any */ | |
1245 | spin_lock_irqsave(&master->queue_lock, flags); | |
1cfd97f9 AL |
1246 | next = list_first_entry_or_null(&master->queue, struct spi_message, |
1247 | queue); | |
ffbbdd21 LW |
1248 | spin_unlock_irqrestore(&master->queue_lock, flags); |
1249 | ||
1250 | return next; | |
1251 | } | |
1252 | EXPORT_SYMBOL_GPL(spi_get_next_queued_message); | |
1253 | ||
1254 | /** | |
1255 | * spi_finalize_current_message() - the current message is complete | |
1256 | * @master: the master to return the message to | |
1257 | * | |
1258 | * Called by the driver to notify the core that the message in the front of the | |
1259 | * queue is complete and can be removed from the queue. | |
1260 | */ | |
1261 | void spi_finalize_current_message(struct spi_master *master) | |
1262 | { | |
1263 | struct spi_message *mesg; | |
1264 | unsigned long flags; | |
2841a5fc | 1265 | int ret; |
ffbbdd21 LW |
1266 | |
1267 | spin_lock_irqsave(&master->queue_lock, flags); | |
1268 | mesg = master->cur_msg; | |
ffbbdd21 LW |
1269 | spin_unlock_irqrestore(&master->queue_lock, flags); |
1270 | ||
99adef31 MB |
1271 | spi_unmap_msg(master, mesg); |
1272 | ||
2841a5fc MB |
1273 | if (master->cur_msg_prepared && master->unprepare_message) { |
1274 | ret = master->unprepare_message(master, mesg); | |
1275 | if (ret) { | |
1276 | dev_err(&master->dev, | |
1277 | "failed to unprepare message: %d\n", ret); | |
1278 | } | |
1279 | } | |
391949b6 | 1280 | |
8e76ef88 MS |
1281 | spin_lock_irqsave(&master->queue_lock, flags); |
1282 | master->cur_msg = NULL; | |
2841a5fc | 1283 | master->cur_msg_prepared = false; |
8e76ef88 MS |
1284 | queue_kthread_work(&master->kworker, &master->pump_messages); |
1285 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1286 | ||
1287 | trace_spi_message_done(mesg); | |
2841a5fc | 1288 | |
ffbbdd21 LW |
1289 | mesg->state = NULL; |
1290 | if (mesg->complete) | |
1291 | mesg->complete(mesg->context); | |
1292 | } | |
1293 | EXPORT_SYMBOL_GPL(spi_finalize_current_message); | |
1294 | ||
1295 | static int spi_start_queue(struct spi_master *master) | |
1296 | { | |
1297 | unsigned long flags; | |
1298 | ||
1299 | spin_lock_irqsave(&master->queue_lock, flags); | |
1300 | ||
1301 | if (master->running || master->busy) { | |
1302 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1303 | return -EBUSY; | |
1304 | } | |
1305 | ||
1306 | master->running = true; | |
1307 | master->cur_msg = NULL; | |
1308 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1309 | ||
1310 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
1311 | ||
1312 | return 0; | |
1313 | } | |
1314 | ||
1315 | static int spi_stop_queue(struct spi_master *master) | |
1316 | { | |
1317 | unsigned long flags; | |
1318 | unsigned limit = 500; | |
1319 | int ret = 0; | |
1320 | ||
1321 | spin_lock_irqsave(&master->queue_lock, flags); | |
1322 | ||
1323 | /* | |
1324 | * This is a bit lame, but is optimized for the common execution path. | |
1325 | * A wait_queue on the master->busy could be used, but then the common | |
1326 | * execution path (pump_messages) would be required to call wake_up or | |
1327 | * friends on every SPI message. Do this instead. | |
1328 | */ | |
1329 | while ((!list_empty(&master->queue) || master->busy) && limit--) { | |
1330 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
f97b26b0 | 1331 | usleep_range(10000, 11000); |
ffbbdd21 LW |
1332 | spin_lock_irqsave(&master->queue_lock, flags); |
1333 | } | |
1334 | ||
1335 | if (!list_empty(&master->queue) || master->busy) | |
1336 | ret = -EBUSY; | |
1337 | else | |
1338 | master->running = false; | |
1339 | ||
1340 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1341 | ||
1342 | if (ret) { | |
1343 | dev_warn(&master->dev, | |
1344 | "could not stop message queue\n"); | |
1345 | return ret; | |
1346 | } | |
1347 | return ret; | |
1348 | } | |
1349 | ||
1350 | static int spi_destroy_queue(struct spi_master *master) | |
1351 | { | |
1352 | int ret; | |
1353 | ||
1354 | ret = spi_stop_queue(master); | |
1355 | ||
1356 | /* | |
1357 | * flush_kthread_worker will block until all work is done. | |
1358 | * If the reason that stop_queue timed out is that the work will never | |
1359 | * finish, then it does no good to call flush/stop thread, so | |
1360 | * return anyway. | |
1361 | */ | |
1362 | if (ret) { | |
1363 | dev_err(&master->dev, "problem destroying queue\n"); | |
1364 | return ret; | |
1365 | } | |
1366 | ||
1367 | flush_kthread_worker(&master->kworker); | |
1368 | kthread_stop(master->kworker_task); | |
1369 | ||
1370 | return 0; | |
1371 | } | |
1372 | ||
0461a414 MB |
1373 | static int __spi_queued_transfer(struct spi_device *spi, |
1374 | struct spi_message *msg, | |
1375 | bool need_pump) | |
ffbbdd21 LW |
1376 | { |
1377 | struct spi_master *master = spi->master; | |
1378 | unsigned long flags; | |
1379 | ||
1380 | spin_lock_irqsave(&master->queue_lock, flags); | |
1381 | ||
1382 | if (!master->running) { | |
1383 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1384 | return -ESHUTDOWN; | |
1385 | } | |
1386 | msg->actual_length = 0; | |
1387 | msg->status = -EINPROGRESS; | |
1388 | ||
1389 | list_add_tail(&msg->queue, &master->queue); | |
0461a414 | 1390 | if (!master->busy && need_pump) |
ffbbdd21 LW |
1391 | queue_kthread_work(&master->kworker, &master->pump_messages); |
1392 | ||
1393 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1394 | return 0; | |
1395 | } | |
1396 | ||
0461a414 MB |
1397 | /** |
1398 | * spi_queued_transfer - transfer function for queued transfers | |
1399 | * @spi: spi device which is requesting transfer | |
1400 | * @msg: spi message which is to handled is queued to driver queue | |
97d56dc6 JMC |
1401 | * |
1402 | * Return: zero on success, else a negative error code. | |
0461a414 MB |
1403 | */ |
1404 | static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) | |
1405 | { | |
1406 | return __spi_queued_transfer(spi, msg, true); | |
1407 | } | |
1408 | ||
ffbbdd21 LW |
1409 | static int spi_master_initialize_queue(struct spi_master *master) |
1410 | { | |
1411 | int ret; | |
1412 | ||
ffbbdd21 | 1413 | master->transfer = spi_queued_transfer; |
b158935f MB |
1414 | if (!master->transfer_one_message) |
1415 | master->transfer_one_message = spi_transfer_one_message; | |
ffbbdd21 LW |
1416 | |
1417 | /* Initialize and start queue */ | |
1418 | ret = spi_init_queue(master); | |
1419 | if (ret) { | |
1420 | dev_err(&master->dev, "problem initializing queue\n"); | |
1421 | goto err_init_queue; | |
1422 | } | |
c3676d5c | 1423 | master->queued = true; |
ffbbdd21 LW |
1424 | ret = spi_start_queue(master); |
1425 | if (ret) { | |
1426 | dev_err(&master->dev, "problem starting queue\n"); | |
1427 | goto err_start_queue; | |
1428 | } | |
1429 | ||
1430 | return 0; | |
1431 | ||
1432 | err_start_queue: | |
ffbbdd21 | 1433 | spi_destroy_queue(master); |
c3676d5c | 1434 | err_init_queue: |
ffbbdd21 LW |
1435 | return ret; |
1436 | } | |
1437 | ||
1438 | /*-------------------------------------------------------------------------*/ | |
1439 | ||
7cb94361 | 1440 | #if defined(CONFIG_OF) |
aff5e3f8 PA |
1441 | static struct spi_device * |
1442 | of_register_spi_device(struct spi_master *master, struct device_node *nc) | |
1443 | { | |
1444 | struct spi_device *spi; | |
1445 | int rc; | |
1446 | u32 value; | |
1447 | ||
1448 | /* Alloc an spi_device */ | |
1449 | spi = spi_alloc_device(master); | |
1450 | if (!spi) { | |
1451 | dev_err(&master->dev, "spi_device alloc error for %s\n", | |
1452 | nc->full_name); | |
1453 | rc = -ENOMEM; | |
1454 | goto err_out; | |
1455 | } | |
1456 | ||
1457 | /* Select device driver */ | |
1458 | rc = of_modalias_node(nc, spi->modalias, | |
1459 | sizeof(spi->modalias)); | |
1460 | if (rc < 0) { | |
1461 | dev_err(&master->dev, "cannot find modalias for %s\n", | |
1462 | nc->full_name); | |
1463 | goto err_out; | |
1464 | } | |
1465 | ||
1466 | /* Device address */ | |
1467 | rc = of_property_read_u32(nc, "reg", &value); | |
1468 | if (rc) { | |
1469 | dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n", | |
1470 | nc->full_name, rc); | |
1471 | goto err_out; | |
1472 | } | |
1473 | spi->chip_select = value; | |
1474 | ||
1475 | /* Mode (clock phase/polarity/etc.) */ | |
1476 | if (of_find_property(nc, "spi-cpha", NULL)) | |
1477 | spi->mode |= SPI_CPHA; | |
1478 | if (of_find_property(nc, "spi-cpol", NULL)) | |
1479 | spi->mode |= SPI_CPOL; | |
1480 | if (of_find_property(nc, "spi-cs-high", NULL)) | |
1481 | spi->mode |= SPI_CS_HIGH; | |
1482 | if (of_find_property(nc, "spi-3wire", NULL)) | |
1483 | spi->mode |= SPI_3WIRE; | |
1484 | if (of_find_property(nc, "spi-lsb-first", NULL)) | |
1485 | spi->mode |= SPI_LSB_FIRST; | |
1486 | ||
1487 | /* Device DUAL/QUAD mode */ | |
1488 | if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { | |
1489 | switch (value) { | |
1490 | case 1: | |
1491 | break; | |
1492 | case 2: | |
1493 | spi->mode |= SPI_TX_DUAL; | |
1494 | break; | |
1495 | case 4: | |
1496 | spi->mode |= SPI_TX_QUAD; | |
1497 | break; | |
1498 | default: | |
1499 | dev_warn(&master->dev, | |
1500 | "spi-tx-bus-width %d not supported\n", | |
1501 | value); | |
1502 | break; | |
1503 | } | |
1504 | } | |
1505 | ||
1506 | if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { | |
1507 | switch (value) { | |
1508 | case 1: | |
1509 | break; | |
1510 | case 2: | |
1511 | spi->mode |= SPI_RX_DUAL; | |
1512 | break; | |
1513 | case 4: | |
1514 | spi->mode |= SPI_RX_QUAD; | |
1515 | break; | |
1516 | default: | |
1517 | dev_warn(&master->dev, | |
1518 | "spi-rx-bus-width %d not supported\n", | |
1519 | value); | |
1520 | break; | |
1521 | } | |
1522 | } | |
1523 | ||
1524 | /* Device speed */ | |
1525 | rc = of_property_read_u32(nc, "spi-max-frequency", &value); | |
1526 | if (rc) { | |
1527 | dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n", | |
1528 | nc->full_name, rc); | |
1529 | goto err_out; | |
1530 | } | |
1531 | spi->max_speed_hz = value; | |
1532 | ||
aff5e3f8 PA |
1533 | /* Store a pointer to the node in the device structure */ |
1534 | of_node_get(nc); | |
1535 | spi->dev.of_node = nc; | |
1536 | ||
1537 | /* Register the new device */ | |
aff5e3f8 PA |
1538 | rc = spi_add_device(spi); |
1539 | if (rc) { | |
1540 | dev_err(&master->dev, "spi_device register error %s\n", | |
1541 | nc->full_name); | |
1542 | goto err_out; | |
1543 | } | |
1544 | ||
1545 | return spi; | |
1546 | ||
1547 | err_out: | |
1548 | spi_dev_put(spi); | |
1549 | return ERR_PTR(rc); | |
1550 | } | |
1551 | ||
d57a4282 GL |
1552 | /** |
1553 | * of_register_spi_devices() - Register child devices onto the SPI bus | |
1554 | * @master: Pointer to spi_master device | |
1555 | * | |
1556 | * Registers an spi_device for each child node of master node which has a 'reg' | |
1557 | * property. | |
1558 | */ | |
1559 | static void of_register_spi_devices(struct spi_master *master) | |
1560 | { | |
1561 | struct spi_device *spi; | |
1562 | struct device_node *nc; | |
d57a4282 GL |
1563 | |
1564 | if (!master->dev.of_node) | |
1565 | return; | |
1566 | ||
f3b6159e | 1567 | for_each_available_child_of_node(master->dev.of_node, nc) { |
bd6c1644 GU |
1568 | if (of_node_test_and_set_flag(nc, OF_POPULATED)) |
1569 | continue; | |
aff5e3f8 PA |
1570 | spi = of_register_spi_device(master, nc); |
1571 | if (IS_ERR(spi)) | |
1572 | dev_warn(&master->dev, "Failed to create SPI device for %s\n", | |
d57a4282 | 1573 | nc->full_name); |
d57a4282 GL |
1574 | } |
1575 | } | |
1576 | #else | |
1577 | static void of_register_spi_devices(struct spi_master *master) { } | |
1578 | #endif | |
1579 | ||
64bee4d2 MW |
1580 | #ifdef CONFIG_ACPI |
1581 | static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) | |
1582 | { | |
1583 | struct spi_device *spi = data; | |
1584 | ||
1585 | if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { | |
1586 | struct acpi_resource_spi_serialbus *sb; | |
1587 | ||
1588 | sb = &ares->data.spi_serial_bus; | |
1589 | if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { | |
1590 | spi->chip_select = sb->device_selection; | |
1591 | spi->max_speed_hz = sb->connection_speed; | |
1592 | ||
1593 | if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) | |
1594 | spi->mode |= SPI_CPHA; | |
1595 | if (sb->clock_polarity == ACPI_SPI_START_HIGH) | |
1596 | spi->mode |= SPI_CPOL; | |
1597 | if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) | |
1598 | spi->mode |= SPI_CS_HIGH; | |
1599 | } | |
1600 | } else if (spi->irq < 0) { | |
1601 | struct resource r; | |
1602 | ||
1603 | if (acpi_dev_resource_interrupt(ares, 0, &r)) | |
1604 | spi->irq = r.start; | |
1605 | } | |
1606 | ||
1607 | /* Always tell the ACPI core to skip this resource */ | |
1608 | return 1; | |
1609 | } | |
1610 | ||
1611 | static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, | |
1612 | void *data, void **return_value) | |
1613 | { | |
1614 | struct spi_master *master = data; | |
1615 | struct list_head resource_list; | |
1616 | struct acpi_device *adev; | |
1617 | struct spi_device *spi; | |
1618 | int ret; | |
1619 | ||
1620 | if (acpi_bus_get_device(handle, &adev)) | |
1621 | return AE_OK; | |
1622 | if (acpi_bus_get_status(adev) || !adev->status.present) | |
1623 | return AE_OK; | |
1624 | ||
1625 | spi = spi_alloc_device(master); | |
1626 | if (!spi) { | |
1627 | dev_err(&master->dev, "failed to allocate SPI device for %s\n", | |
1628 | dev_name(&adev->dev)); | |
1629 | return AE_NO_MEMORY; | |
1630 | } | |
1631 | ||
7b199811 | 1632 | ACPI_COMPANION_SET(&spi->dev, adev); |
64bee4d2 MW |
1633 | spi->irq = -1; |
1634 | ||
1635 | INIT_LIST_HEAD(&resource_list); | |
1636 | ret = acpi_dev_get_resources(adev, &resource_list, | |
1637 | acpi_spi_add_resource, spi); | |
1638 | acpi_dev_free_resource_list(&resource_list); | |
1639 | ||
1640 | if (ret < 0 || !spi->max_speed_hz) { | |
1641 | spi_dev_put(spi); | |
1642 | return AE_OK; | |
1643 | } | |
1644 | ||
33ada67d CR |
1645 | if (spi->irq < 0) |
1646 | spi->irq = acpi_dev_gpio_irq_get(adev, 0); | |
1647 | ||
33cf00e5 | 1648 | adev->power.flags.ignore_parent = true; |
cf9eb39c | 1649 | strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias)); |
64bee4d2 | 1650 | if (spi_add_device(spi)) { |
33cf00e5 | 1651 | adev->power.flags.ignore_parent = false; |
64bee4d2 MW |
1652 | dev_err(&master->dev, "failed to add SPI device %s from ACPI\n", |
1653 | dev_name(&adev->dev)); | |
1654 | spi_dev_put(spi); | |
1655 | } | |
1656 | ||
1657 | return AE_OK; | |
1658 | } | |
1659 | ||
1660 | static void acpi_register_spi_devices(struct spi_master *master) | |
1661 | { | |
1662 | acpi_status status; | |
1663 | acpi_handle handle; | |
1664 | ||
29896178 | 1665 | handle = ACPI_HANDLE(master->dev.parent); |
64bee4d2 MW |
1666 | if (!handle) |
1667 | return; | |
1668 | ||
1669 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, | |
1670 | acpi_spi_add_device, NULL, | |
1671 | master, NULL); | |
1672 | if (ACPI_FAILURE(status)) | |
1673 | dev_warn(&master->dev, "failed to enumerate SPI slaves\n"); | |
1674 | } | |
1675 | #else | |
1676 | static inline void acpi_register_spi_devices(struct spi_master *master) {} | |
1677 | #endif /* CONFIG_ACPI */ | |
1678 | ||
49dce689 | 1679 | static void spi_master_release(struct device *dev) |
8ae12a0d DB |
1680 | { |
1681 | struct spi_master *master; | |
1682 | ||
49dce689 | 1683 | master = container_of(dev, struct spi_master, dev); |
8ae12a0d DB |
1684 | kfree(master); |
1685 | } | |
1686 | ||
1687 | static struct class spi_master_class = { | |
1688 | .name = "spi_master", | |
1689 | .owner = THIS_MODULE, | |
49dce689 | 1690 | .dev_release = spi_master_release, |
eca2ebc7 | 1691 | .dev_groups = spi_master_groups, |
8ae12a0d DB |
1692 | }; |
1693 | ||
1694 | ||
1695 | /** | |
1696 | * spi_alloc_master - allocate SPI master controller | |
1697 | * @dev: the controller, possibly using the platform_bus | |
33e34dc6 | 1698 | * @size: how much zeroed driver-private data to allocate; the pointer to this |
49dce689 | 1699 | * memory is in the driver_data field of the returned device, |
0c868461 | 1700 | * accessible with spi_master_get_devdata(). |
33e34dc6 | 1701 | * Context: can sleep |
8ae12a0d DB |
1702 | * |
1703 | * This call is used only by SPI master controller drivers, which are the | |
1704 | * only ones directly touching chip registers. It's how they allocate | |
ba1a0513 | 1705 | * an spi_master structure, prior to calling spi_register_master(). |
8ae12a0d | 1706 | * |
97d56dc6 | 1707 | * This must be called from context that can sleep. |
8ae12a0d DB |
1708 | * |
1709 | * The caller is responsible for assigning the bus number and initializing | |
ba1a0513 | 1710 | * the master's methods before calling spi_register_master(); and (after errors |
a394d635 | 1711 | * adding the device) calling spi_master_put() to prevent a memory leak. |
97d56dc6 JMC |
1712 | * |
1713 | * Return: the SPI master structure on success, else NULL. | |
8ae12a0d | 1714 | */ |
e9d5a461 | 1715 | struct spi_master *spi_alloc_master(struct device *dev, unsigned size) |
8ae12a0d DB |
1716 | { |
1717 | struct spi_master *master; | |
1718 | ||
0c868461 DB |
1719 | if (!dev) |
1720 | return NULL; | |
1721 | ||
5fe5f05e | 1722 | master = kzalloc(size + sizeof(*master), GFP_KERNEL); |
8ae12a0d DB |
1723 | if (!master) |
1724 | return NULL; | |
1725 | ||
49dce689 | 1726 | device_initialize(&master->dev); |
1e8a52e1 GL |
1727 | master->bus_num = -1; |
1728 | master->num_chipselect = 1; | |
49dce689 | 1729 | master->dev.class = &spi_master_class; |
157f38f9 | 1730 | master->dev.parent = dev; |
0c868461 | 1731 | spi_master_set_devdata(master, &master[1]); |
8ae12a0d DB |
1732 | |
1733 | return master; | |
1734 | } | |
1735 | EXPORT_SYMBOL_GPL(spi_alloc_master); | |
1736 | ||
74317984 JCPV |
1737 | #ifdef CONFIG_OF |
1738 | static int of_spi_register_master(struct spi_master *master) | |
1739 | { | |
e80beb27 | 1740 | int nb, i, *cs; |
74317984 JCPV |
1741 | struct device_node *np = master->dev.of_node; |
1742 | ||
1743 | if (!np) | |
1744 | return 0; | |
1745 | ||
1746 | nb = of_gpio_named_count(np, "cs-gpios"); | |
5fe5f05e | 1747 | master->num_chipselect = max_t(int, nb, master->num_chipselect); |
74317984 | 1748 | |
8ec5d84e AL |
1749 | /* Return error only for an incorrectly formed cs-gpios property */ |
1750 | if (nb == 0 || nb == -ENOENT) | |
74317984 | 1751 | return 0; |
8ec5d84e AL |
1752 | else if (nb < 0) |
1753 | return nb; | |
74317984 JCPV |
1754 | |
1755 | cs = devm_kzalloc(&master->dev, | |
1756 | sizeof(int) * master->num_chipselect, | |
1757 | GFP_KERNEL); | |
1758 | master->cs_gpios = cs; | |
1759 | ||
1760 | if (!master->cs_gpios) | |
1761 | return -ENOMEM; | |
1762 | ||
0da83bb1 | 1763 | for (i = 0; i < master->num_chipselect; i++) |
446411e1 | 1764 | cs[i] = -ENOENT; |
74317984 JCPV |
1765 | |
1766 | for (i = 0; i < nb; i++) | |
1767 | cs[i] = of_get_named_gpio(np, "cs-gpios", i); | |
1768 | ||
1769 | return 0; | |
1770 | } | |
1771 | #else | |
1772 | static int of_spi_register_master(struct spi_master *master) | |
1773 | { | |
1774 | return 0; | |
1775 | } | |
1776 | #endif | |
1777 | ||
8ae12a0d DB |
1778 | /** |
1779 | * spi_register_master - register SPI master controller | |
1780 | * @master: initialized master, originally from spi_alloc_master() | |
33e34dc6 | 1781 | * Context: can sleep |
8ae12a0d DB |
1782 | * |
1783 | * SPI master controllers connect to their drivers using some non-SPI bus, | |
1784 | * such as the platform bus. The final stage of probe() in that code | |
1785 | * includes calling spi_register_master() to hook up to this SPI bus glue. | |
1786 | * | |
1787 | * SPI controllers use board specific (often SOC specific) bus numbers, | |
1788 | * and board-specific addressing for SPI devices combines those numbers | |
1789 | * with chip select numbers. Since SPI does not directly support dynamic | |
1790 | * device identification, boards need configuration tables telling which | |
1791 | * chip is at which address. | |
1792 | * | |
1793 | * This must be called from context that can sleep. It returns zero on | |
1794 | * success, else a negative error code (dropping the master's refcount). | |
0c868461 DB |
1795 | * After a successful return, the caller is responsible for calling |
1796 | * spi_unregister_master(). | |
97d56dc6 JMC |
1797 | * |
1798 | * Return: zero on success, else a negative error code. | |
8ae12a0d | 1799 | */ |
e9d5a461 | 1800 | int spi_register_master(struct spi_master *master) |
8ae12a0d | 1801 | { |
e44a45ae | 1802 | static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1); |
49dce689 | 1803 | struct device *dev = master->dev.parent; |
2b9603a0 | 1804 | struct boardinfo *bi; |
8ae12a0d DB |
1805 | int status = -ENODEV; |
1806 | int dynamic = 0; | |
1807 | ||
0c868461 DB |
1808 | if (!dev) |
1809 | return -ENODEV; | |
1810 | ||
74317984 JCPV |
1811 | status = of_spi_register_master(master); |
1812 | if (status) | |
1813 | return status; | |
1814 | ||
082c8cb4 DB |
1815 | /* even if it's just one always-selected device, there must |
1816 | * be at least one chipselect | |
1817 | */ | |
1818 | if (master->num_chipselect == 0) | |
1819 | return -EINVAL; | |
1820 | ||
bb29785e GL |
1821 | if ((master->bus_num < 0) && master->dev.of_node) |
1822 | master->bus_num = of_alias_get_id(master->dev.of_node, "spi"); | |
1823 | ||
8ae12a0d | 1824 | /* convention: dynamically assigned bus IDs count down from the max */ |
a020ed75 | 1825 | if (master->bus_num < 0) { |
082c8cb4 DB |
1826 | /* FIXME switch to an IDR based scheme, something like |
1827 | * I2C now uses, so we can't run out of "dynamic" IDs | |
1828 | */ | |
8ae12a0d | 1829 | master->bus_num = atomic_dec_return(&dyn_bus_id); |
b885244e | 1830 | dynamic = 1; |
8ae12a0d DB |
1831 | } |
1832 | ||
5424d43e MB |
1833 | INIT_LIST_HEAD(&master->queue); |
1834 | spin_lock_init(&master->queue_lock); | |
cf32b71e ES |
1835 | spin_lock_init(&master->bus_lock_spinlock); |
1836 | mutex_init(&master->bus_lock_mutex); | |
1837 | master->bus_lock_flag = 0; | |
b158935f | 1838 | init_completion(&master->xfer_completion); |
6ad45a27 MB |
1839 | if (!master->max_dma_len) |
1840 | master->max_dma_len = INT_MAX; | |
cf32b71e | 1841 | |
8ae12a0d DB |
1842 | /* register the device, then userspace will see it. |
1843 | * registration fails if the bus ID is in use. | |
1844 | */ | |
35f74fca | 1845 | dev_set_name(&master->dev, "spi%u", master->bus_num); |
49dce689 | 1846 | status = device_add(&master->dev); |
b885244e | 1847 | if (status < 0) |
8ae12a0d | 1848 | goto done; |
35f74fca | 1849 | dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), |
8ae12a0d DB |
1850 | dynamic ? " (dynamic)" : ""); |
1851 | ||
ffbbdd21 LW |
1852 | /* If we're using a queued driver, start the queue */ |
1853 | if (master->transfer) | |
1854 | dev_info(dev, "master is unqueued, this is deprecated\n"); | |
1855 | else { | |
1856 | status = spi_master_initialize_queue(master); | |
1857 | if (status) { | |
e93b0724 | 1858 | device_del(&master->dev); |
ffbbdd21 LW |
1859 | goto done; |
1860 | } | |
1861 | } | |
eca2ebc7 MS |
1862 | /* add statistics */ |
1863 | spin_lock_init(&master->statistics.lock); | |
ffbbdd21 | 1864 | |
2b9603a0 FT |
1865 | mutex_lock(&board_lock); |
1866 | list_add_tail(&master->list, &spi_master_list); | |
1867 | list_for_each_entry(bi, &board_list, list) | |
1868 | spi_match_master_to_boardinfo(master, &bi->board_info); | |
1869 | mutex_unlock(&board_lock); | |
1870 | ||
64bee4d2 | 1871 | /* Register devices from the device tree and ACPI */ |
12b15e83 | 1872 | of_register_spi_devices(master); |
64bee4d2 | 1873 | acpi_register_spi_devices(master); |
8ae12a0d DB |
1874 | done: |
1875 | return status; | |
1876 | } | |
1877 | EXPORT_SYMBOL_GPL(spi_register_master); | |
1878 | ||
666d5b4c MB |
1879 | static void devm_spi_unregister(struct device *dev, void *res) |
1880 | { | |
1881 | spi_unregister_master(*(struct spi_master **)res); | |
1882 | } | |
1883 | ||
1884 | /** | |
1885 | * dev_spi_register_master - register managed SPI master controller | |
1886 | * @dev: device managing SPI master | |
1887 | * @master: initialized master, originally from spi_alloc_master() | |
1888 | * Context: can sleep | |
1889 | * | |
1890 | * Register a SPI device as with spi_register_master() which will | |
1891 | * automatically be unregister | |
97d56dc6 JMC |
1892 | * |
1893 | * Return: zero on success, else a negative error code. | |
666d5b4c MB |
1894 | */ |
1895 | int devm_spi_register_master(struct device *dev, struct spi_master *master) | |
1896 | { | |
1897 | struct spi_master **ptr; | |
1898 | int ret; | |
1899 | ||
1900 | ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL); | |
1901 | if (!ptr) | |
1902 | return -ENOMEM; | |
1903 | ||
1904 | ret = spi_register_master(master); | |
4b92894e | 1905 | if (!ret) { |
666d5b4c MB |
1906 | *ptr = master; |
1907 | devres_add(dev, ptr); | |
1908 | } else { | |
1909 | devres_free(ptr); | |
1910 | } | |
1911 | ||
1912 | return ret; | |
1913 | } | |
1914 | EXPORT_SYMBOL_GPL(devm_spi_register_master); | |
1915 | ||
34860089 | 1916 | static int __unregister(struct device *dev, void *null) |
8ae12a0d | 1917 | { |
34860089 | 1918 | spi_unregister_device(to_spi_device(dev)); |
8ae12a0d DB |
1919 | return 0; |
1920 | } | |
1921 | ||
1922 | /** | |
1923 | * spi_unregister_master - unregister SPI master controller | |
1924 | * @master: the master being unregistered | |
33e34dc6 | 1925 | * Context: can sleep |
8ae12a0d DB |
1926 | * |
1927 | * This call is used only by SPI master controller drivers, which are the | |
1928 | * only ones directly touching chip registers. | |
1929 | * | |
1930 | * This must be called from context that can sleep. | |
1931 | */ | |
1932 | void spi_unregister_master(struct spi_master *master) | |
1933 | { | |
89fc9a1a JG |
1934 | int dummy; |
1935 | ||
ffbbdd21 LW |
1936 | if (master->queued) { |
1937 | if (spi_destroy_queue(master)) | |
1938 | dev_err(&master->dev, "queue remove failed\n"); | |
1939 | } | |
1940 | ||
2b9603a0 FT |
1941 | mutex_lock(&board_lock); |
1942 | list_del(&master->list); | |
1943 | mutex_unlock(&board_lock); | |
1944 | ||
97dbf37d | 1945 | dummy = device_for_each_child(&master->dev, NULL, __unregister); |
49dce689 | 1946 | device_unregister(&master->dev); |
8ae12a0d DB |
1947 | } |
1948 | EXPORT_SYMBOL_GPL(spi_unregister_master); | |
1949 | ||
ffbbdd21 LW |
1950 | int spi_master_suspend(struct spi_master *master) |
1951 | { | |
1952 | int ret; | |
1953 | ||
1954 | /* Basically no-ops for non-queued masters */ | |
1955 | if (!master->queued) | |
1956 | return 0; | |
1957 | ||
1958 | ret = spi_stop_queue(master); | |
1959 | if (ret) | |
1960 | dev_err(&master->dev, "queue stop failed\n"); | |
1961 | ||
1962 | return ret; | |
1963 | } | |
1964 | EXPORT_SYMBOL_GPL(spi_master_suspend); | |
1965 | ||
1966 | int spi_master_resume(struct spi_master *master) | |
1967 | { | |
1968 | int ret; | |
1969 | ||
1970 | if (!master->queued) | |
1971 | return 0; | |
1972 | ||
1973 | ret = spi_start_queue(master); | |
1974 | if (ret) | |
1975 | dev_err(&master->dev, "queue restart failed\n"); | |
1976 | ||
1977 | return ret; | |
1978 | } | |
1979 | EXPORT_SYMBOL_GPL(spi_master_resume); | |
1980 | ||
9f3b795a | 1981 | static int __spi_master_match(struct device *dev, const void *data) |
5ed2c832 DY |
1982 | { |
1983 | struct spi_master *m; | |
9f3b795a | 1984 | const u16 *bus_num = data; |
5ed2c832 DY |
1985 | |
1986 | m = container_of(dev, struct spi_master, dev); | |
1987 | return m->bus_num == *bus_num; | |
1988 | } | |
1989 | ||
8ae12a0d DB |
1990 | /** |
1991 | * spi_busnum_to_master - look up master associated with bus_num | |
1992 | * @bus_num: the master's bus number | |
33e34dc6 | 1993 | * Context: can sleep |
8ae12a0d DB |
1994 | * |
1995 | * This call may be used with devices that are registered after | |
1996 | * arch init time. It returns a refcounted pointer to the relevant | |
1997 | * spi_master (which the caller must release), or NULL if there is | |
1998 | * no such master registered. | |
97d56dc6 JMC |
1999 | * |
2000 | * Return: the SPI master structure on success, else NULL. | |
8ae12a0d DB |
2001 | */ |
2002 | struct spi_master *spi_busnum_to_master(u16 bus_num) | |
2003 | { | |
49dce689 | 2004 | struct device *dev; |
1e9a51dc | 2005 | struct spi_master *master = NULL; |
5ed2c832 | 2006 | |
695794ae | 2007 | dev = class_find_device(&spi_master_class, NULL, &bus_num, |
5ed2c832 DY |
2008 | __spi_master_match); |
2009 | if (dev) | |
2010 | master = container_of(dev, struct spi_master, dev); | |
2011 | /* reference got in class_find_device */ | |
1e9a51dc | 2012 | return master; |
8ae12a0d DB |
2013 | } |
2014 | EXPORT_SYMBOL_GPL(spi_busnum_to_master); | |
2015 | ||
2016 | ||
2017 | /*-------------------------------------------------------------------------*/ | |
2018 | ||
7d077197 DB |
2019 | /* Core methods for SPI master protocol drivers. Some of the |
2020 | * other core methods are currently defined as inline functions. | |
2021 | */ | |
2022 | ||
63ab645f SB |
2023 | static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word) |
2024 | { | |
2025 | if (master->bits_per_word_mask) { | |
2026 | /* Only 32 bits fit in the mask */ | |
2027 | if (bits_per_word > 32) | |
2028 | return -EINVAL; | |
2029 | if (!(master->bits_per_word_mask & | |
2030 | SPI_BPW_MASK(bits_per_word))) | |
2031 | return -EINVAL; | |
2032 | } | |
2033 | ||
2034 | return 0; | |
2035 | } | |
2036 | ||
7d077197 DB |
2037 | /** |
2038 | * spi_setup - setup SPI mode and clock rate | |
2039 | * @spi: the device whose settings are being modified | |
2040 | * Context: can sleep, and no requests are queued to the device | |
2041 | * | |
2042 | * SPI protocol drivers may need to update the transfer mode if the | |
2043 | * device doesn't work with its default. They may likewise need | |
2044 | * to update clock rates or word sizes from initial values. This function | |
2045 | * changes those settings, and must be called from a context that can sleep. | |
2046 | * Except for SPI_CS_HIGH, which takes effect immediately, the changes take | |
2047 | * effect the next time the device is selected and data is transferred to | |
2048 | * or from it. When this function returns, the spi device is deselected. | |
2049 | * | |
2050 | * Note that this call will fail if the protocol driver specifies an option | |
2051 | * that the underlying controller or its driver does not support. For | |
2052 | * example, not all hardware supports wire transfers using nine bit words, | |
2053 | * LSB-first wire encoding, or active-high chipselects. | |
97d56dc6 JMC |
2054 | * |
2055 | * Return: zero on success, else a negative error code. | |
7d077197 DB |
2056 | */ |
2057 | int spi_setup(struct spi_device *spi) | |
2058 | { | |
83596fbe | 2059 | unsigned bad_bits, ugly_bits; |
5ab8d262 | 2060 | int status; |
7d077197 | 2061 | |
f477b7fb | 2062 | /* check mode to prevent that DUAL and QUAD set at the same time |
2063 | */ | |
2064 | if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) || | |
2065 | ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) { | |
2066 | dev_err(&spi->dev, | |
2067 | "setup: can not select dual and quad at the same time\n"); | |
2068 | return -EINVAL; | |
2069 | } | |
2070 | /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden | |
2071 | */ | |
2072 | if ((spi->mode & SPI_3WIRE) && (spi->mode & | |
2073 | (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD))) | |
2074 | return -EINVAL; | |
e7db06b5 DB |
2075 | /* help drivers fail *cleanly* when they need options |
2076 | * that aren't supported with their current master | |
2077 | */ | |
2078 | bad_bits = spi->mode & ~spi->master->mode_bits; | |
83596fbe GU |
2079 | ugly_bits = bad_bits & |
2080 | (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD); | |
2081 | if (ugly_bits) { | |
2082 | dev_warn(&spi->dev, | |
2083 | "setup: ignoring unsupported mode bits %x\n", | |
2084 | ugly_bits); | |
2085 | spi->mode &= ~ugly_bits; | |
2086 | bad_bits &= ~ugly_bits; | |
2087 | } | |
e7db06b5 | 2088 | if (bad_bits) { |
eb288a1f | 2089 | dev_err(&spi->dev, "setup: unsupported mode bits %x\n", |
e7db06b5 DB |
2090 | bad_bits); |
2091 | return -EINVAL; | |
2092 | } | |
2093 | ||
7d077197 DB |
2094 | if (!spi->bits_per_word) |
2095 | spi->bits_per_word = 8; | |
2096 | ||
5ab8d262 AS |
2097 | status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word); |
2098 | if (status) | |
2099 | return status; | |
63ab645f | 2100 | |
052eb2d4 AL |
2101 | if (!spi->max_speed_hz) |
2102 | spi->max_speed_hz = spi->master->max_speed_hz; | |
2103 | ||
caae070c LD |
2104 | if (spi->master->setup) |
2105 | status = spi->master->setup(spi); | |
7d077197 | 2106 | |
abeedb01 FCJ |
2107 | spi_set_cs(spi, false); |
2108 | ||
5fe5f05e | 2109 | dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", |
7d077197 DB |
2110 | (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), |
2111 | (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", | |
2112 | (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", | |
2113 | (spi->mode & SPI_3WIRE) ? "3wire, " : "", | |
2114 | (spi->mode & SPI_LOOP) ? "loopback, " : "", | |
2115 | spi->bits_per_word, spi->max_speed_hz, | |
2116 | status); | |
2117 | ||
2118 | return status; | |
2119 | } | |
2120 | EXPORT_SYMBOL_GPL(spi_setup); | |
2121 | ||
90808738 | 2122 | static int __spi_validate(struct spi_device *spi, struct spi_message *message) |
cf32b71e ES |
2123 | { |
2124 | struct spi_master *master = spi->master; | |
e6811d1d | 2125 | struct spi_transfer *xfer; |
6ea31293 | 2126 | int w_size; |
cf32b71e | 2127 | |
24a0013a MB |
2128 | if (list_empty(&message->transfers)) |
2129 | return -EINVAL; | |
24a0013a | 2130 | |
cf32b71e ES |
2131 | /* Half-duplex links include original MicroWire, and ones with |
2132 | * only one data pin like SPI_3WIRE (switches direction) or where | |
2133 | * either MOSI or MISO is missing. They can also be caused by | |
2134 | * software limitations. | |
2135 | */ | |
2136 | if ((master->flags & SPI_MASTER_HALF_DUPLEX) | |
2137 | || (spi->mode & SPI_3WIRE)) { | |
cf32b71e ES |
2138 | unsigned flags = master->flags; |
2139 | ||
2140 | list_for_each_entry(xfer, &message->transfers, transfer_list) { | |
2141 | if (xfer->rx_buf && xfer->tx_buf) | |
2142 | return -EINVAL; | |
2143 | if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf) | |
2144 | return -EINVAL; | |
2145 | if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf) | |
2146 | return -EINVAL; | |
2147 | } | |
2148 | } | |
2149 | ||
e6811d1d | 2150 | /** |
059b8ffe LD |
2151 | * Set transfer bits_per_word and max speed as spi device default if |
2152 | * it is not set for this transfer. | |
f477b7fb | 2153 | * Set transfer tx_nbits and rx_nbits as single transfer default |
2154 | * (SPI_NBITS_SINGLE) if it is not set for this transfer. | |
e6811d1d | 2155 | */ |
77e80588 | 2156 | message->frame_length = 0; |
e6811d1d | 2157 | list_for_each_entry(xfer, &message->transfers, transfer_list) { |
078726ce | 2158 | message->frame_length += xfer->len; |
e6811d1d LD |
2159 | if (!xfer->bits_per_word) |
2160 | xfer->bits_per_word = spi->bits_per_word; | |
a6f87fad AL |
2161 | |
2162 | if (!xfer->speed_hz) | |
059b8ffe | 2163 | xfer->speed_hz = spi->max_speed_hz; |
7dc9fbc3 MB |
2164 | if (!xfer->speed_hz) |
2165 | xfer->speed_hz = master->max_speed_hz; | |
a6f87fad AL |
2166 | |
2167 | if (master->max_speed_hz && | |
2168 | xfer->speed_hz > master->max_speed_hz) | |
2169 | xfer->speed_hz = master->max_speed_hz; | |
56ede94a | 2170 | |
63ab645f SB |
2171 | if (__spi_validate_bits_per_word(master, xfer->bits_per_word)) |
2172 | return -EINVAL; | |
a2fd4f9f | 2173 | |
4d94bd21 II |
2174 | /* |
2175 | * SPI transfer length should be multiple of SPI word size | |
2176 | * where SPI word size should be power-of-two multiple | |
2177 | */ | |
2178 | if (xfer->bits_per_word <= 8) | |
2179 | w_size = 1; | |
2180 | else if (xfer->bits_per_word <= 16) | |
2181 | w_size = 2; | |
2182 | else | |
2183 | w_size = 4; | |
2184 | ||
4d94bd21 | 2185 | /* No partial transfers accepted */ |
6ea31293 | 2186 | if (xfer->len % w_size) |
4d94bd21 II |
2187 | return -EINVAL; |
2188 | ||
a2fd4f9f MB |
2189 | if (xfer->speed_hz && master->min_speed_hz && |
2190 | xfer->speed_hz < master->min_speed_hz) | |
2191 | return -EINVAL; | |
f477b7fb | 2192 | |
2193 | if (xfer->tx_buf && !xfer->tx_nbits) | |
2194 | xfer->tx_nbits = SPI_NBITS_SINGLE; | |
2195 | if (xfer->rx_buf && !xfer->rx_nbits) | |
2196 | xfer->rx_nbits = SPI_NBITS_SINGLE; | |
2197 | /* check transfer tx/rx_nbits: | |
1afd9989 GU |
2198 | * 1. check the value matches one of single, dual and quad |
2199 | * 2. check tx/rx_nbits match the mode in spi_device | |
f477b7fb | 2200 | */ |
db90a441 SP |
2201 | if (xfer->tx_buf) { |
2202 | if (xfer->tx_nbits != SPI_NBITS_SINGLE && | |
2203 | xfer->tx_nbits != SPI_NBITS_DUAL && | |
2204 | xfer->tx_nbits != SPI_NBITS_QUAD) | |
2205 | return -EINVAL; | |
2206 | if ((xfer->tx_nbits == SPI_NBITS_DUAL) && | |
2207 | !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) | |
2208 | return -EINVAL; | |
2209 | if ((xfer->tx_nbits == SPI_NBITS_QUAD) && | |
2210 | !(spi->mode & SPI_TX_QUAD)) | |
2211 | return -EINVAL; | |
db90a441 | 2212 | } |
f477b7fb | 2213 | /* check transfer rx_nbits */ |
db90a441 SP |
2214 | if (xfer->rx_buf) { |
2215 | if (xfer->rx_nbits != SPI_NBITS_SINGLE && | |
2216 | xfer->rx_nbits != SPI_NBITS_DUAL && | |
2217 | xfer->rx_nbits != SPI_NBITS_QUAD) | |
2218 | return -EINVAL; | |
2219 | if ((xfer->rx_nbits == SPI_NBITS_DUAL) && | |
2220 | !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) | |
2221 | return -EINVAL; | |
2222 | if ((xfer->rx_nbits == SPI_NBITS_QUAD) && | |
2223 | !(spi->mode & SPI_RX_QUAD)) | |
2224 | return -EINVAL; | |
db90a441 | 2225 | } |
e6811d1d LD |
2226 | } |
2227 | ||
cf32b71e | 2228 | message->status = -EINPROGRESS; |
90808738 MB |
2229 | |
2230 | return 0; | |
2231 | } | |
2232 | ||
2233 | static int __spi_async(struct spi_device *spi, struct spi_message *message) | |
2234 | { | |
2235 | struct spi_master *master = spi->master; | |
2236 | ||
2237 | message->spi = spi; | |
2238 | ||
eca2ebc7 MS |
2239 | SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async); |
2240 | SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async); | |
2241 | ||
90808738 MB |
2242 | trace_spi_message_submit(message); |
2243 | ||
cf32b71e ES |
2244 | return master->transfer(spi, message); |
2245 | } | |
2246 | ||
568d0697 DB |
2247 | /** |
2248 | * spi_async - asynchronous SPI transfer | |
2249 | * @spi: device with which data will be exchanged | |
2250 | * @message: describes the data transfers, including completion callback | |
2251 | * Context: any (irqs may be blocked, etc) | |
2252 | * | |
2253 | * This call may be used in_irq and other contexts which can't sleep, | |
2254 | * as well as from task contexts which can sleep. | |
2255 | * | |
2256 | * The completion callback is invoked in a context which can't sleep. | |
2257 | * Before that invocation, the value of message->status is undefined. | |
2258 | * When the callback is issued, message->status holds either zero (to | |
2259 | * indicate complete success) or a negative error code. After that | |
2260 | * callback returns, the driver which issued the transfer request may | |
2261 | * deallocate the associated memory; it's no longer in use by any SPI | |
2262 | * core or controller driver code. | |
2263 | * | |
2264 | * Note that although all messages to a spi_device are handled in | |
2265 | * FIFO order, messages may go to different devices in other orders. | |
2266 | * Some device might be higher priority, or have various "hard" access | |
2267 | * time requirements, for example. | |
2268 | * | |
2269 | * On detection of any fault during the transfer, processing of | |
2270 | * the entire message is aborted, and the device is deselected. | |
2271 | * Until returning from the associated message completion callback, | |
2272 | * no other spi_message queued to that device will be processed. | |
2273 | * (This rule applies equally to all the synchronous transfer calls, | |
2274 | * which are wrappers around this core asynchronous primitive.) | |
97d56dc6 JMC |
2275 | * |
2276 | * Return: zero on success, else a negative error code. | |
568d0697 DB |
2277 | */ |
2278 | int spi_async(struct spi_device *spi, struct spi_message *message) | |
2279 | { | |
2280 | struct spi_master *master = spi->master; | |
cf32b71e ES |
2281 | int ret; |
2282 | unsigned long flags; | |
568d0697 | 2283 | |
90808738 MB |
2284 | ret = __spi_validate(spi, message); |
2285 | if (ret != 0) | |
2286 | return ret; | |
2287 | ||
cf32b71e | 2288 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
568d0697 | 2289 | |
cf32b71e ES |
2290 | if (master->bus_lock_flag) |
2291 | ret = -EBUSY; | |
2292 | else | |
2293 | ret = __spi_async(spi, message); | |
568d0697 | 2294 | |
cf32b71e ES |
2295 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
2296 | ||
2297 | return ret; | |
568d0697 DB |
2298 | } |
2299 | EXPORT_SYMBOL_GPL(spi_async); | |
2300 | ||
cf32b71e ES |
2301 | /** |
2302 | * spi_async_locked - version of spi_async with exclusive bus usage | |
2303 | * @spi: device with which data will be exchanged | |
2304 | * @message: describes the data transfers, including completion callback | |
2305 | * Context: any (irqs may be blocked, etc) | |
2306 | * | |
2307 | * This call may be used in_irq and other contexts which can't sleep, | |
2308 | * as well as from task contexts which can sleep. | |
2309 | * | |
2310 | * The completion callback is invoked in a context which can't sleep. | |
2311 | * Before that invocation, the value of message->status is undefined. | |
2312 | * When the callback is issued, message->status holds either zero (to | |
2313 | * indicate complete success) or a negative error code. After that | |
2314 | * callback returns, the driver which issued the transfer request may | |
2315 | * deallocate the associated memory; it's no longer in use by any SPI | |
2316 | * core or controller driver code. | |
2317 | * | |
2318 | * Note that although all messages to a spi_device are handled in | |
2319 | * FIFO order, messages may go to different devices in other orders. | |
2320 | * Some device might be higher priority, or have various "hard" access | |
2321 | * time requirements, for example. | |
2322 | * | |
2323 | * On detection of any fault during the transfer, processing of | |
2324 | * the entire message is aborted, and the device is deselected. | |
2325 | * Until returning from the associated message completion callback, | |
2326 | * no other spi_message queued to that device will be processed. | |
2327 | * (This rule applies equally to all the synchronous transfer calls, | |
2328 | * which are wrappers around this core asynchronous primitive.) | |
97d56dc6 JMC |
2329 | * |
2330 | * Return: zero on success, else a negative error code. | |
cf32b71e ES |
2331 | */ |
2332 | int spi_async_locked(struct spi_device *spi, struct spi_message *message) | |
2333 | { | |
2334 | struct spi_master *master = spi->master; | |
2335 | int ret; | |
2336 | unsigned long flags; | |
2337 | ||
90808738 MB |
2338 | ret = __spi_validate(spi, message); |
2339 | if (ret != 0) | |
2340 | return ret; | |
2341 | ||
cf32b71e ES |
2342 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
2343 | ||
2344 | ret = __spi_async(spi, message); | |
2345 | ||
2346 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
2347 | ||
2348 | return ret; | |
2349 | ||
2350 | } | |
2351 | EXPORT_SYMBOL_GPL(spi_async_locked); | |
2352 | ||
7d077197 DB |
2353 | |
2354 | /*-------------------------------------------------------------------------*/ | |
2355 | ||
2356 | /* Utility methods for SPI master protocol drivers, layered on | |
2357 | * top of the core. Some other utility methods are defined as | |
2358 | * inline functions. | |
2359 | */ | |
2360 | ||
5d870c8e AM |
2361 | static void spi_complete(void *arg) |
2362 | { | |
2363 | complete(arg); | |
2364 | } | |
2365 | ||
cf32b71e ES |
2366 | static int __spi_sync(struct spi_device *spi, struct spi_message *message, |
2367 | int bus_locked) | |
2368 | { | |
2369 | DECLARE_COMPLETION_ONSTACK(done); | |
2370 | int status; | |
2371 | struct spi_master *master = spi->master; | |
0461a414 MB |
2372 | unsigned long flags; |
2373 | ||
2374 | status = __spi_validate(spi, message); | |
2375 | if (status != 0) | |
2376 | return status; | |
cf32b71e ES |
2377 | |
2378 | message->complete = spi_complete; | |
2379 | message->context = &done; | |
0461a414 | 2380 | message->spi = spi; |
cf32b71e | 2381 | |
eca2ebc7 MS |
2382 | SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync); |
2383 | SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync); | |
2384 | ||
cf32b71e ES |
2385 | if (!bus_locked) |
2386 | mutex_lock(&master->bus_lock_mutex); | |
2387 | ||
0461a414 MB |
2388 | /* If we're not using the legacy transfer method then we will |
2389 | * try to transfer in the calling context so special case. | |
2390 | * This code would be less tricky if we could remove the | |
2391 | * support for driver implemented message queues. | |
2392 | */ | |
2393 | if (master->transfer == spi_queued_transfer) { | |
2394 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); | |
2395 | ||
2396 | trace_spi_message_submit(message); | |
2397 | ||
2398 | status = __spi_queued_transfer(spi, message, false); | |
2399 | ||
2400 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
2401 | } else { | |
2402 | status = spi_async_locked(spi, message); | |
2403 | } | |
cf32b71e ES |
2404 | |
2405 | if (!bus_locked) | |
2406 | mutex_unlock(&master->bus_lock_mutex); | |
2407 | ||
2408 | if (status == 0) { | |
0461a414 MB |
2409 | /* Push out the messages in the calling context if we |
2410 | * can. | |
2411 | */ | |
eca2ebc7 MS |
2412 | if (master->transfer == spi_queued_transfer) { |
2413 | SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, | |
2414 | spi_sync_immediate); | |
2415 | SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, | |
2416 | spi_sync_immediate); | |
fc9e0f71 | 2417 | __spi_pump_messages(master, false); |
eca2ebc7 | 2418 | } |
0461a414 | 2419 | |
cf32b71e ES |
2420 | wait_for_completion(&done); |
2421 | status = message->status; | |
2422 | } | |
2423 | message->context = NULL; | |
2424 | return status; | |
2425 | } | |
2426 | ||
8ae12a0d DB |
2427 | /** |
2428 | * spi_sync - blocking/synchronous SPI data transfers | |
2429 | * @spi: device with which data will be exchanged | |
2430 | * @message: describes the data transfers | |
33e34dc6 | 2431 | * Context: can sleep |
8ae12a0d DB |
2432 | * |
2433 | * This call may only be used from a context that may sleep. The sleep | |
2434 | * is non-interruptible, and has no timeout. Low-overhead controller | |
2435 | * drivers may DMA directly into and out of the message buffers. | |
2436 | * | |
2437 | * Note that the SPI device's chip select is active during the message, | |
2438 | * and then is normally disabled between messages. Drivers for some | |
2439 | * frequently-used devices may want to minimize costs of selecting a chip, | |
2440 | * by leaving it selected in anticipation that the next message will go | |
2441 | * to the same chip. (That may increase power usage.) | |
2442 | * | |
0c868461 DB |
2443 | * Also, the caller is guaranteeing that the memory associated with the |
2444 | * message will not be freed before this call returns. | |
2445 | * | |
97d56dc6 | 2446 | * Return: zero on success, else a negative error code. |
8ae12a0d DB |
2447 | */ |
2448 | int spi_sync(struct spi_device *spi, struct spi_message *message) | |
2449 | { | |
cf32b71e | 2450 | return __spi_sync(spi, message, 0); |
8ae12a0d DB |
2451 | } |
2452 | EXPORT_SYMBOL_GPL(spi_sync); | |
2453 | ||
cf32b71e ES |
2454 | /** |
2455 | * spi_sync_locked - version of spi_sync with exclusive bus usage | |
2456 | * @spi: device with which data will be exchanged | |
2457 | * @message: describes the data transfers | |
2458 | * Context: can sleep | |
2459 | * | |
2460 | * This call may only be used from a context that may sleep. The sleep | |
2461 | * is non-interruptible, and has no timeout. Low-overhead controller | |
2462 | * drivers may DMA directly into and out of the message buffers. | |
2463 | * | |
2464 | * This call should be used by drivers that require exclusive access to the | |
25985edc | 2465 | * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must |
cf32b71e ES |
2466 | * be released by a spi_bus_unlock call when the exclusive access is over. |
2467 | * | |
97d56dc6 | 2468 | * Return: zero on success, else a negative error code. |
cf32b71e ES |
2469 | */ |
2470 | int spi_sync_locked(struct spi_device *spi, struct spi_message *message) | |
2471 | { | |
2472 | return __spi_sync(spi, message, 1); | |
2473 | } | |
2474 | EXPORT_SYMBOL_GPL(spi_sync_locked); | |
2475 | ||
2476 | /** | |
2477 | * spi_bus_lock - obtain a lock for exclusive SPI bus usage | |
2478 | * @master: SPI bus master that should be locked for exclusive bus access | |
2479 | * Context: can sleep | |
2480 | * | |
2481 | * This call may only be used from a context that may sleep. The sleep | |
2482 | * is non-interruptible, and has no timeout. | |
2483 | * | |
2484 | * This call should be used by drivers that require exclusive access to the | |
2485 | * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the | |
2486 | * exclusive access is over. Data transfer must be done by spi_sync_locked | |
2487 | * and spi_async_locked calls when the SPI bus lock is held. | |
2488 | * | |
97d56dc6 | 2489 | * Return: always zero. |
cf32b71e ES |
2490 | */ |
2491 | int spi_bus_lock(struct spi_master *master) | |
2492 | { | |
2493 | unsigned long flags; | |
2494 | ||
2495 | mutex_lock(&master->bus_lock_mutex); | |
2496 | ||
2497 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); | |
2498 | master->bus_lock_flag = 1; | |
2499 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
2500 | ||
2501 | /* mutex remains locked until spi_bus_unlock is called */ | |
2502 | ||
2503 | return 0; | |
2504 | } | |
2505 | EXPORT_SYMBOL_GPL(spi_bus_lock); | |
2506 | ||
2507 | /** | |
2508 | * spi_bus_unlock - release the lock for exclusive SPI bus usage | |
2509 | * @master: SPI bus master that was locked for exclusive bus access | |
2510 | * Context: can sleep | |
2511 | * | |
2512 | * This call may only be used from a context that may sleep. The sleep | |
2513 | * is non-interruptible, and has no timeout. | |
2514 | * | |
2515 | * This call releases an SPI bus lock previously obtained by an spi_bus_lock | |
2516 | * call. | |
2517 | * | |
97d56dc6 | 2518 | * Return: always zero. |
cf32b71e ES |
2519 | */ |
2520 | int spi_bus_unlock(struct spi_master *master) | |
2521 | { | |
2522 | master->bus_lock_flag = 0; | |
2523 | ||
2524 | mutex_unlock(&master->bus_lock_mutex); | |
2525 | ||
2526 | return 0; | |
2527 | } | |
2528 | EXPORT_SYMBOL_GPL(spi_bus_unlock); | |
2529 | ||
a9948b61 | 2530 | /* portable code must never pass more than 32 bytes */ |
5fe5f05e | 2531 | #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) |
8ae12a0d DB |
2532 | |
2533 | static u8 *buf; | |
2534 | ||
2535 | /** | |
2536 | * spi_write_then_read - SPI synchronous write followed by read | |
2537 | * @spi: device with which data will be exchanged | |
2538 | * @txbuf: data to be written (need not be dma-safe) | |
2539 | * @n_tx: size of txbuf, in bytes | |
27570497 JP |
2540 | * @rxbuf: buffer into which data will be read (need not be dma-safe) |
2541 | * @n_rx: size of rxbuf, in bytes | |
33e34dc6 | 2542 | * Context: can sleep |
8ae12a0d DB |
2543 | * |
2544 | * This performs a half duplex MicroWire style transaction with the | |
2545 | * device, sending txbuf and then reading rxbuf. The return value | |
2546 | * is zero for success, else a negative errno status code. | |
b885244e | 2547 | * This call may only be used from a context that may sleep. |
8ae12a0d | 2548 | * |
0c868461 | 2549 | * Parameters to this routine are always copied using a small buffer; |
33e34dc6 DB |
2550 | * portable code should never use this for more than 32 bytes. |
2551 | * Performance-sensitive or bulk transfer code should instead use | |
0c868461 | 2552 | * spi_{async,sync}() calls with dma-safe buffers. |
97d56dc6 JMC |
2553 | * |
2554 | * Return: zero on success, else a negative error code. | |
8ae12a0d DB |
2555 | */ |
2556 | int spi_write_then_read(struct spi_device *spi, | |
0c4a1590 MB |
2557 | const void *txbuf, unsigned n_tx, |
2558 | void *rxbuf, unsigned n_rx) | |
8ae12a0d | 2559 | { |
068f4070 | 2560 | static DEFINE_MUTEX(lock); |
8ae12a0d DB |
2561 | |
2562 | int status; | |
2563 | struct spi_message message; | |
bdff549e | 2564 | struct spi_transfer x[2]; |
8ae12a0d DB |
2565 | u8 *local_buf; |
2566 | ||
b3a223ee MB |
2567 | /* Use preallocated DMA-safe buffer if we can. We can't avoid |
2568 | * copying here, (as a pure convenience thing), but we can | |
2569 | * keep heap costs out of the hot path unless someone else is | |
2570 | * using the pre-allocated buffer or the transfer is too large. | |
8ae12a0d | 2571 | */ |
b3a223ee | 2572 | if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { |
2cd94c8a MB |
2573 | local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), |
2574 | GFP_KERNEL | GFP_DMA); | |
b3a223ee MB |
2575 | if (!local_buf) |
2576 | return -ENOMEM; | |
2577 | } else { | |
2578 | local_buf = buf; | |
2579 | } | |
8ae12a0d | 2580 | |
8275c642 | 2581 | spi_message_init(&message); |
5fe5f05e | 2582 | memset(x, 0, sizeof(x)); |
bdff549e DB |
2583 | if (n_tx) { |
2584 | x[0].len = n_tx; | |
2585 | spi_message_add_tail(&x[0], &message); | |
2586 | } | |
2587 | if (n_rx) { | |
2588 | x[1].len = n_rx; | |
2589 | spi_message_add_tail(&x[1], &message); | |
2590 | } | |
8275c642 | 2591 | |
8ae12a0d | 2592 | memcpy(local_buf, txbuf, n_tx); |
bdff549e DB |
2593 | x[0].tx_buf = local_buf; |
2594 | x[1].rx_buf = local_buf + n_tx; | |
8ae12a0d DB |
2595 | |
2596 | /* do the i/o */ | |
8ae12a0d | 2597 | status = spi_sync(spi, &message); |
9b938b74 | 2598 | if (status == 0) |
bdff549e | 2599 | memcpy(rxbuf, x[1].rx_buf, n_rx); |
8ae12a0d | 2600 | |
bdff549e | 2601 | if (x[0].tx_buf == buf) |
068f4070 | 2602 | mutex_unlock(&lock); |
8ae12a0d DB |
2603 | else |
2604 | kfree(local_buf); | |
2605 | ||
2606 | return status; | |
2607 | } | |
2608 | EXPORT_SYMBOL_GPL(spi_write_then_read); | |
2609 | ||
2610 | /*-------------------------------------------------------------------------*/ | |
2611 | ||
ce79d54a PA |
2612 | #if IS_ENABLED(CONFIG_OF_DYNAMIC) |
2613 | static int __spi_of_device_match(struct device *dev, void *data) | |
2614 | { | |
2615 | return dev->of_node == data; | |
2616 | } | |
2617 | ||
2618 | /* must call put_device() when done with returned spi_device device */ | |
2619 | static struct spi_device *of_find_spi_device_by_node(struct device_node *node) | |
2620 | { | |
2621 | struct device *dev = bus_find_device(&spi_bus_type, NULL, node, | |
2622 | __spi_of_device_match); | |
2623 | return dev ? to_spi_device(dev) : NULL; | |
2624 | } | |
2625 | ||
2626 | static int __spi_of_master_match(struct device *dev, const void *data) | |
2627 | { | |
2628 | return dev->of_node == data; | |
2629 | } | |
2630 | ||
2631 | /* the spi masters are not using spi_bus, so we find it with another way */ | |
2632 | static struct spi_master *of_find_spi_master_by_node(struct device_node *node) | |
2633 | { | |
2634 | struct device *dev; | |
2635 | ||
2636 | dev = class_find_device(&spi_master_class, NULL, node, | |
2637 | __spi_of_master_match); | |
2638 | if (!dev) | |
2639 | return NULL; | |
2640 | ||
2641 | /* reference got in class_find_device */ | |
2642 | return container_of(dev, struct spi_master, dev); | |
2643 | } | |
2644 | ||
2645 | static int of_spi_notify(struct notifier_block *nb, unsigned long action, | |
2646 | void *arg) | |
2647 | { | |
2648 | struct of_reconfig_data *rd = arg; | |
2649 | struct spi_master *master; | |
2650 | struct spi_device *spi; | |
2651 | ||
2652 | switch (of_reconfig_get_state_change(action, arg)) { | |
2653 | case OF_RECONFIG_CHANGE_ADD: | |
2654 | master = of_find_spi_master_by_node(rd->dn->parent); | |
2655 | if (master == NULL) | |
2656 | return NOTIFY_OK; /* not for us */ | |
2657 | ||
bd6c1644 GU |
2658 | if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { |
2659 | put_device(&master->dev); | |
2660 | return NOTIFY_OK; | |
2661 | } | |
2662 | ||
ce79d54a PA |
2663 | spi = of_register_spi_device(master, rd->dn); |
2664 | put_device(&master->dev); | |
2665 | ||
2666 | if (IS_ERR(spi)) { | |
2667 | pr_err("%s: failed to create for '%s'\n", | |
2668 | __func__, rd->dn->full_name); | |
2669 | return notifier_from_errno(PTR_ERR(spi)); | |
2670 | } | |
2671 | break; | |
2672 | ||
2673 | case OF_RECONFIG_CHANGE_REMOVE: | |
bd6c1644 GU |
2674 | /* already depopulated? */ |
2675 | if (!of_node_check_flag(rd->dn, OF_POPULATED)) | |
2676 | return NOTIFY_OK; | |
2677 | ||
ce79d54a PA |
2678 | /* find our device by node */ |
2679 | spi = of_find_spi_device_by_node(rd->dn); | |
2680 | if (spi == NULL) | |
2681 | return NOTIFY_OK; /* no? not meant for us */ | |
2682 | ||
2683 | /* unregister takes one ref away */ | |
2684 | spi_unregister_device(spi); | |
2685 | ||
2686 | /* and put the reference of the find */ | |
2687 | put_device(&spi->dev); | |
2688 | break; | |
2689 | } | |
2690 | ||
2691 | return NOTIFY_OK; | |
2692 | } | |
2693 | ||
2694 | static struct notifier_block spi_of_notifier = { | |
2695 | .notifier_call = of_spi_notify, | |
2696 | }; | |
2697 | #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ | |
2698 | extern struct notifier_block spi_of_notifier; | |
2699 | #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ | |
2700 | ||
8ae12a0d DB |
2701 | static int __init spi_init(void) |
2702 | { | |
b885244e DB |
2703 | int status; |
2704 | ||
e94b1766 | 2705 | buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); |
b885244e DB |
2706 | if (!buf) { |
2707 | status = -ENOMEM; | |
2708 | goto err0; | |
2709 | } | |
2710 | ||
2711 | status = bus_register(&spi_bus_type); | |
2712 | if (status < 0) | |
2713 | goto err1; | |
8ae12a0d | 2714 | |
b885244e DB |
2715 | status = class_register(&spi_master_class); |
2716 | if (status < 0) | |
2717 | goto err2; | |
ce79d54a | 2718 | |
5267720e | 2719 | if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
ce79d54a PA |
2720 | WARN_ON(of_reconfig_notifier_register(&spi_of_notifier)); |
2721 | ||
8ae12a0d | 2722 | return 0; |
b885244e DB |
2723 | |
2724 | err2: | |
2725 | bus_unregister(&spi_bus_type); | |
2726 | err1: | |
2727 | kfree(buf); | |
2728 | buf = NULL; | |
2729 | err0: | |
2730 | return status; | |
8ae12a0d | 2731 | } |
b885244e | 2732 | |
8ae12a0d DB |
2733 | /* board_info is normally registered in arch_initcall(), |
2734 | * but even essential drivers wait till later | |
b885244e DB |
2735 | * |
2736 | * REVISIT only boardinfo really needs static linking. the rest (device and | |
2737 | * driver registration) _could_ be dynamically linked (modular) ... costs | |
2738 | * include needing to have boardinfo data structures be much more public. | |
8ae12a0d | 2739 | */ |
673c0c00 | 2740 | postcore_initcall(spi_init); |
8ae12a0d | 2741 |