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Commit | Line | Data |
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0c2498f1 SH |
1 | /* |
2 | * Generic pwmlib implementation | |
3 | * | |
4 | * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de> | |
f051c466 | 5 | * Copyright (C) 2011-2012 Avionic Design GmbH |
0c2498f1 SH |
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, or (at your option) | |
10 | * any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; see the file COPYING. If not, write to | |
19 | * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | */ | |
21 | ||
22 | #include <linux/module.h> | |
23 | #include <linux/pwm.h> | |
f051c466 | 24 | #include <linux/radix-tree.h> |
0c2498f1 SH |
25 | #include <linux/list.h> |
26 | #include <linux/mutex.h> | |
27 | #include <linux/err.h> | |
28 | #include <linux/slab.h> | |
29 | #include <linux/device.h> | |
62099abf TR |
30 | #include <linux/debugfs.h> |
31 | #include <linux/seq_file.h> | |
0c2498f1 | 32 | |
208be769 | 33 | #include <dt-bindings/pwm/pwm.h> |
0c2498f1 | 34 | |
208be769 | 35 | #define MAX_PWMS 1024 |
83af2402 | 36 | |
8138d2dd TR |
37 | static DEFINE_MUTEX(pwm_lookup_lock); |
38 | static LIST_HEAD(pwm_lookup_list); | |
0c2498f1 | 39 | static DEFINE_MUTEX(pwm_lock); |
f051c466 TR |
40 | static LIST_HEAD(pwm_chips); |
41 | static DECLARE_BITMAP(allocated_pwms, MAX_PWMS); | |
42 | static RADIX_TREE(pwm_tree, GFP_KERNEL); | |
0c2498f1 | 43 | |
f051c466 | 44 | static struct pwm_device *pwm_to_device(unsigned int pwm) |
0c2498f1 | 45 | { |
f051c466 TR |
46 | return radix_tree_lookup(&pwm_tree, pwm); |
47 | } | |
48 | ||
49 | static int alloc_pwms(int pwm, unsigned int count) | |
50 | { | |
51 | unsigned int from = 0; | |
52 | unsigned int start; | |
53 | ||
54 | if (pwm >= MAX_PWMS) | |
55 | return -EINVAL; | |
56 | ||
57 | if (pwm >= 0) | |
58 | from = pwm; | |
0c2498f1 | 59 | |
f051c466 TR |
60 | start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from, |
61 | count, 0); | |
62 | ||
63 | if (pwm >= 0 && start != pwm) | |
64 | return -EEXIST; | |
65 | ||
66 | if (start + count > MAX_PWMS) | |
67 | return -ENOSPC; | |
68 | ||
69 | return start; | |
70 | } | |
71 | ||
72 | static void free_pwms(struct pwm_chip *chip) | |
73 | { | |
74 | unsigned int i; | |
75 | ||
76 | for (i = 0; i < chip->npwm; i++) { | |
77 | struct pwm_device *pwm = &chip->pwms[i]; | |
78 | radix_tree_delete(&pwm_tree, pwm->pwm); | |
0c2498f1 SH |
79 | } |
80 | ||
f051c466 TR |
81 | bitmap_clear(allocated_pwms, chip->base, chip->npwm); |
82 | ||
83 | kfree(chip->pwms); | |
84 | chip->pwms = NULL; | |
85 | } | |
86 | ||
8138d2dd TR |
87 | static struct pwm_chip *pwmchip_find_by_name(const char *name) |
88 | { | |
89 | struct pwm_chip *chip; | |
90 | ||
91 | if (!name) | |
92 | return NULL; | |
93 | ||
94 | mutex_lock(&pwm_lock); | |
95 | ||
96 | list_for_each_entry(chip, &pwm_chips, list) { | |
97 | const char *chip_name = dev_name(chip->dev); | |
98 | ||
99 | if (chip_name && strcmp(chip_name, name) == 0) { | |
100 | mutex_unlock(&pwm_lock); | |
101 | return chip; | |
102 | } | |
103 | } | |
104 | ||
105 | mutex_unlock(&pwm_lock); | |
106 | ||
107 | return NULL; | |
108 | } | |
109 | ||
f051c466 TR |
110 | static int pwm_device_request(struct pwm_device *pwm, const char *label) |
111 | { | |
112 | int err; | |
113 | ||
114 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
115 | return -EBUSY; | |
116 | ||
117 | if (!try_module_get(pwm->chip->ops->owner)) | |
118 | return -ENODEV; | |
119 | ||
120 | if (pwm->chip->ops->request) { | |
121 | err = pwm->chip->ops->request(pwm->chip, pwm); | |
122 | if (err) { | |
123 | module_put(pwm->chip->ops->owner); | |
124 | return err; | |
125 | } | |
126 | } | |
127 | ||
128 | set_bit(PWMF_REQUESTED, &pwm->flags); | |
129 | pwm->label = label; | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
83af2402 PA |
134 | struct pwm_device * |
135 | of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) | |
136 | { | |
137 | struct pwm_device *pwm; | |
138 | ||
139 | if (pc->of_pwm_n_cells < 3) | |
140 | return ERR_PTR(-EINVAL); | |
141 | ||
142 | if (args->args[0] >= pc->npwm) | |
143 | return ERR_PTR(-EINVAL); | |
144 | ||
145 | pwm = pwm_request_from_chip(pc, args->args[0], NULL); | |
146 | if (IS_ERR(pwm)) | |
147 | return pwm; | |
148 | ||
149 | pwm_set_period(pwm, args->args[1]); | |
150 | ||
208be769 | 151 | if (args->args[2] & PWM_POLARITY_INVERTED) |
83af2402 PA |
152 | pwm_set_polarity(pwm, PWM_POLARITY_INVERSED); |
153 | else | |
154 | pwm_set_polarity(pwm, PWM_POLARITY_NORMAL); | |
155 | ||
156 | return pwm; | |
157 | } | |
417328c3 | 158 | EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags); |
83af2402 | 159 | |
e50d3523 SK |
160 | static struct pwm_device * |
161 | of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) | |
7299ab70 TR |
162 | { |
163 | struct pwm_device *pwm; | |
164 | ||
165 | if (pc->of_pwm_n_cells < 2) | |
166 | return ERR_PTR(-EINVAL); | |
167 | ||
168 | if (args->args[0] >= pc->npwm) | |
169 | return ERR_PTR(-EINVAL); | |
170 | ||
171 | pwm = pwm_request_from_chip(pc, args->args[0], NULL); | |
172 | if (IS_ERR(pwm)) | |
173 | return pwm; | |
174 | ||
175 | pwm_set_period(pwm, args->args[1]); | |
176 | ||
177 | return pwm; | |
178 | } | |
179 | ||
dfeb86ec | 180 | static void of_pwmchip_add(struct pwm_chip *chip) |
7299ab70 TR |
181 | { |
182 | if (!chip->dev || !chip->dev->of_node) | |
183 | return; | |
184 | ||
185 | if (!chip->of_xlate) { | |
186 | chip->of_xlate = of_pwm_simple_xlate; | |
187 | chip->of_pwm_n_cells = 2; | |
188 | } | |
189 | ||
190 | of_node_get(chip->dev->of_node); | |
191 | } | |
192 | ||
dfeb86ec | 193 | static void of_pwmchip_remove(struct pwm_chip *chip) |
7299ab70 | 194 | { |
8d6cc073 | 195 | if (chip->dev) |
7299ab70 TR |
196 | of_node_put(chip->dev->of_node); |
197 | } | |
198 | ||
f051c466 TR |
199 | /** |
200 | * pwm_set_chip_data() - set private chip data for a PWM | |
201 | * @pwm: PWM device | |
202 | * @data: pointer to chip-specific data | |
203 | */ | |
204 | int pwm_set_chip_data(struct pwm_device *pwm, void *data) | |
205 | { | |
206 | if (!pwm) | |
207 | return -EINVAL; | |
208 | ||
209 | pwm->chip_data = data; | |
210 | ||
211 | return 0; | |
212 | } | |
928c4477 | 213 | EXPORT_SYMBOL_GPL(pwm_set_chip_data); |
f051c466 TR |
214 | |
215 | /** | |
216 | * pwm_get_chip_data() - get private chip data for a PWM | |
217 | * @pwm: PWM device | |
218 | */ | |
219 | void *pwm_get_chip_data(struct pwm_device *pwm) | |
220 | { | |
221 | return pwm ? pwm->chip_data : NULL; | |
0c2498f1 | 222 | } |
928c4477 | 223 | EXPORT_SYMBOL_GPL(pwm_get_chip_data); |
0c2498f1 SH |
224 | |
225 | /** | |
b6a00fae | 226 | * pwmchip_add_with_polarity() - register a new PWM chip |
0c2498f1 | 227 | * @chip: the PWM chip to add |
b6a00fae | 228 | * @polarity: initial polarity of PWM channels |
f051c466 TR |
229 | * |
230 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base | |
b6a00fae TK |
231 | * will be used. The initial polarity for all channels is specified by the |
232 | * @polarity parameter. | |
0c2498f1 | 233 | */ |
b6a00fae TK |
234 | int pwmchip_add_with_polarity(struct pwm_chip *chip, |
235 | enum pwm_polarity polarity) | |
0c2498f1 SH |
236 | { |
237 | struct pwm_device *pwm; | |
f051c466 TR |
238 | unsigned int i; |
239 | int ret; | |
0c2498f1 | 240 | |
f051c466 | 241 | if (!chip || !chip->dev || !chip->ops || !chip->ops->config || |
533acc0e | 242 | !chip->ops->enable || !chip->ops->disable || !chip->npwm) |
f051c466 | 243 | return -EINVAL; |
0c2498f1 SH |
244 | |
245 | mutex_lock(&pwm_lock); | |
246 | ||
f051c466 TR |
247 | ret = alloc_pwms(chip->base, chip->npwm); |
248 | if (ret < 0) | |
249 | goto out; | |
250 | ||
251 | chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL); | |
252 | if (!chip->pwms) { | |
253 | ret = -ENOMEM; | |
0c2498f1 SH |
254 | goto out; |
255 | } | |
256 | ||
f051c466 TR |
257 | chip->base = ret; |
258 | ||
259 | for (i = 0; i < chip->npwm; i++) { | |
260 | pwm = &chip->pwms[i]; | |
261 | ||
262 | pwm->chip = chip; | |
263 | pwm->pwm = chip->base + i; | |
264 | pwm->hwpwm = i; | |
b6a00fae | 265 | pwm->polarity = polarity; |
0c2498f1 | 266 | |
f051c466 TR |
267 | radix_tree_insert(&pwm_tree, pwm->pwm, pwm); |
268 | } | |
269 | ||
270 | bitmap_set(allocated_pwms, chip->base, chip->npwm); | |
271 | ||
272 | INIT_LIST_HEAD(&chip->list); | |
273 | list_add(&chip->list, &pwm_chips); | |
0c2498f1 | 274 | |
f051c466 TR |
275 | ret = 0; |
276 | ||
7299ab70 TR |
277 | if (IS_ENABLED(CONFIG_OF)) |
278 | of_pwmchip_add(chip); | |
279 | ||
76abbdde HS |
280 | pwmchip_sysfs_export(chip); |
281 | ||
f051c466 TR |
282 | out: |
283 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
284 | return ret; |
285 | } | |
b6a00fae TK |
286 | EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity); |
287 | ||
288 | /** | |
289 | * pwmchip_add() - register a new PWM chip | |
290 | * @chip: the PWM chip to add | |
291 | * | |
292 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base | |
293 | * will be used. The initial polarity for all channels is normal. | |
294 | */ | |
295 | int pwmchip_add(struct pwm_chip *chip) | |
296 | { | |
297 | return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL); | |
298 | } | |
0c2498f1 SH |
299 | EXPORT_SYMBOL_GPL(pwmchip_add); |
300 | ||
301 | /** | |
302 | * pwmchip_remove() - remove a PWM chip | |
303 | * @chip: the PWM chip to remove | |
304 | * | |
305 | * Removes a PWM chip. This function may return busy if the PWM chip provides | |
306 | * a PWM device that is still requested. | |
307 | */ | |
308 | int pwmchip_remove(struct pwm_chip *chip) | |
309 | { | |
f051c466 | 310 | unsigned int i; |
0c2498f1 SH |
311 | int ret = 0; |
312 | ||
313 | mutex_lock(&pwm_lock); | |
314 | ||
f051c466 TR |
315 | for (i = 0; i < chip->npwm; i++) { |
316 | struct pwm_device *pwm = &chip->pwms[i]; | |
0c2498f1 | 317 | |
f051c466 TR |
318 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) { |
319 | ret = -EBUSY; | |
320 | goto out; | |
321 | } | |
0c2498f1 SH |
322 | } |
323 | ||
f051c466 | 324 | list_del_init(&chip->list); |
7299ab70 TR |
325 | |
326 | if (IS_ENABLED(CONFIG_OF)) | |
327 | of_pwmchip_remove(chip); | |
328 | ||
f051c466 | 329 | free_pwms(chip); |
0c2498f1 | 330 | |
76abbdde HS |
331 | pwmchip_sysfs_unexport(chip); |
332 | ||
0c2498f1 SH |
333 | out: |
334 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
335 | return ret; |
336 | } | |
337 | EXPORT_SYMBOL_GPL(pwmchip_remove); | |
338 | ||
339 | /** | |
340 | * pwm_request() - request a PWM device | |
341 | * @pwm_id: global PWM device index | |
342 | * @label: PWM device label | |
8138d2dd TR |
343 | * |
344 | * This function is deprecated, use pwm_get() instead. | |
0c2498f1 | 345 | */ |
f051c466 | 346 | struct pwm_device *pwm_request(int pwm, const char *label) |
0c2498f1 | 347 | { |
f051c466 TR |
348 | struct pwm_device *dev; |
349 | int err; | |
350 | ||
351 | if (pwm < 0 || pwm >= MAX_PWMS) | |
352 | return ERR_PTR(-EINVAL); | |
0c2498f1 SH |
353 | |
354 | mutex_lock(&pwm_lock); | |
355 | ||
f051c466 TR |
356 | dev = pwm_to_device(pwm); |
357 | if (!dev) { | |
358 | dev = ERR_PTR(-EPROBE_DEFER); | |
0c2498f1 SH |
359 | goto out; |
360 | } | |
361 | ||
f051c466 TR |
362 | err = pwm_device_request(dev, label); |
363 | if (err < 0) | |
364 | dev = ERR_PTR(err); | |
0c2498f1 | 365 | |
f051c466 TR |
366 | out: |
367 | mutex_unlock(&pwm_lock); | |
0c2498f1 | 368 | |
f051c466 TR |
369 | return dev; |
370 | } | |
371 | EXPORT_SYMBOL_GPL(pwm_request); | |
0c2498f1 | 372 | |
f051c466 TR |
373 | /** |
374 | * pwm_request_from_chip() - request a PWM device relative to a PWM chip | |
375 | * @chip: PWM chip | |
376 | * @index: per-chip index of the PWM to request | |
377 | * @label: a literal description string of this PWM | |
378 | * | |
379 | * Returns the PWM at the given index of the given PWM chip. A negative error | |
380 | * code is returned if the index is not valid for the specified PWM chip or | |
381 | * if the PWM device cannot be requested. | |
382 | */ | |
383 | struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, | |
384 | unsigned int index, | |
385 | const char *label) | |
386 | { | |
387 | struct pwm_device *pwm; | |
388 | int err; | |
0c2498f1 | 389 | |
f051c466 TR |
390 | if (!chip || index >= chip->npwm) |
391 | return ERR_PTR(-EINVAL); | |
0c2498f1 | 392 | |
f051c466 TR |
393 | mutex_lock(&pwm_lock); |
394 | pwm = &chip->pwms[index]; | |
0c2498f1 | 395 | |
f051c466 TR |
396 | err = pwm_device_request(pwm, label); |
397 | if (err < 0) | |
398 | pwm = ERR_PTR(err); | |
399 | ||
400 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
401 | return pwm; |
402 | } | |
f051c466 | 403 | EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
0c2498f1 SH |
404 | |
405 | /** | |
406 | * pwm_free() - free a PWM device | |
407 | * @pwm: PWM device | |
8138d2dd TR |
408 | * |
409 | * This function is deprecated, use pwm_put() instead. | |
0c2498f1 SH |
410 | */ |
411 | void pwm_free(struct pwm_device *pwm) | |
412 | { | |
8138d2dd | 413 | pwm_put(pwm); |
0c2498f1 SH |
414 | } |
415 | EXPORT_SYMBOL_GPL(pwm_free); | |
416 | ||
417 | /** | |
418 | * pwm_config() - change a PWM device configuration | |
419 | * @pwm: PWM device | |
420 | * @duty_ns: "on" time (in nanoseconds) | |
421 | * @period_ns: duration (in nanoseconds) of one cycle | |
422 | */ | |
423 | int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) | |
424 | { | |
76abbdde HS |
425 | int err; |
426 | ||
c2d476a9 | 427 | if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns) |
f051c466 TR |
428 | return -EINVAL; |
429 | ||
76abbdde HS |
430 | err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); |
431 | if (err) | |
432 | return err; | |
433 | ||
434 | pwm->duty_cycle = duty_ns; | |
435 | pwm->period = period_ns; | |
436 | ||
437 | return 0; | |
0c2498f1 SH |
438 | } |
439 | EXPORT_SYMBOL_GPL(pwm_config); | |
440 | ||
0aa0869c PA |
441 | /** |
442 | * pwm_set_polarity() - configure the polarity of a PWM signal | |
443 | * @pwm: PWM device | |
444 | * @polarity: new polarity of the PWM signal | |
445 | * | |
446 | * Note that the polarity cannot be configured while the PWM device is enabled | |
447 | */ | |
448 | int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) | |
449 | { | |
76abbdde HS |
450 | int err; |
451 | ||
0aa0869c PA |
452 | if (!pwm || !pwm->chip->ops) |
453 | return -EINVAL; | |
454 | ||
455 | if (!pwm->chip->ops->set_polarity) | |
456 | return -ENOSYS; | |
457 | ||
458 | if (test_bit(PWMF_ENABLED, &pwm->flags)) | |
459 | return -EBUSY; | |
460 | ||
76abbdde HS |
461 | err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity); |
462 | if (err) | |
463 | return err; | |
464 | ||
465 | pwm->polarity = polarity; | |
466 | ||
467 | return 0; | |
0aa0869c PA |
468 | } |
469 | EXPORT_SYMBOL_GPL(pwm_set_polarity); | |
470 | ||
0c2498f1 SH |
471 | /** |
472 | * pwm_enable() - start a PWM output toggling | |
473 | * @pwm: PWM device | |
474 | */ | |
475 | int pwm_enable(struct pwm_device *pwm) | |
476 | { | |
f051c466 TR |
477 | if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags)) |
478 | return pwm->chip->ops->enable(pwm->chip, pwm); | |
0c2498f1 | 479 | |
f051c466 | 480 | return pwm ? 0 : -EINVAL; |
0c2498f1 SH |
481 | } |
482 | EXPORT_SYMBOL_GPL(pwm_enable); | |
483 | ||
484 | /** | |
485 | * pwm_disable() - stop a PWM output toggling | |
486 | * @pwm: PWM device | |
487 | */ | |
488 | void pwm_disable(struct pwm_device *pwm) | |
489 | { | |
f051c466 TR |
490 | if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags)) |
491 | pwm->chip->ops->disable(pwm->chip, pwm); | |
0c2498f1 SH |
492 | } |
493 | EXPORT_SYMBOL_GPL(pwm_disable); | |
62099abf | 494 | |
7299ab70 TR |
495 | static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) |
496 | { | |
497 | struct pwm_chip *chip; | |
498 | ||
499 | mutex_lock(&pwm_lock); | |
500 | ||
501 | list_for_each_entry(chip, &pwm_chips, list) | |
502 | if (chip->dev && chip->dev->of_node == np) { | |
503 | mutex_unlock(&pwm_lock); | |
504 | return chip; | |
505 | } | |
506 | ||
507 | mutex_unlock(&pwm_lock); | |
508 | ||
509 | return ERR_PTR(-EPROBE_DEFER); | |
510 | } | |
511 | ||
512 | /** | |
8eb96127 | 513 | * of_pwm_get() - request a PWM via the PWM framework |
7299ab70 TR |
514 | * @np: device node to get the PWM from |
515 | * @con_id: consumer name | |
516 | * | |
517 | * Returns the PWM device parsed from the phandle and index specified in the | |
518 | * "pwms" property of a device tree node or a negative error-code on failure. | |
519 | * Values parsed from the device tree are stored in the returned PWM device | |
520 | * object. | |
521 | * | |
522 | * If con_id is NULL, the first PWM device listed in the "pwms" property will | |
523 | * be requested. Otherwise the "pwm-names" property is used to do a reverse | |
524 | * lookup of the PWM index. This also means that the "pwm-names" property | |
525 | * becomes mandatory for devices that look up the PWM device via the con_id | |
526 | * parameter. | |
527 | */ | |
8eb96127 | 528 | struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) |
7299ab70 TR |
529 | { |
530 | struct pwm_device *pwm = NULL; | |
531 | struct of_phandle_args args; | |
532 | struct pwm_chip *pc; | |
533 | int index = 0; | |
534 | int err; | |
535 | ||
536 | if (con_id) { | |
537 | index = of_property_match_string(np, "pwm-names", con_id); | |
538 | if (index < 0) | |
539 | return ERR_PTR(index); | |
540 | } | |
541 | ||
542 | err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, | |
543 | &args); | |
544 | if (err) { | |
545 | pr_debug("%s(): can't parse \"pwms\" property\n", __func__); | |
546 | return ERR_PTR(err); | |
547 | } | |
548 | ||
549 | pc = of_node_to_pwmchip(args.np); | |
550 | if (IS_ERR(pc)) { | |
551 | pr_debug("%s(): PWM chip not found\n", __func__); | |
552 | pwm = ERR_CAST(pc); | |
553 | goto put; | |
554 | } | |
555 | ||
556 | if (args.args_count != pc->of_pwm_n_cells) { | |
557 | pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name, | |
558 | args.np->full_name); | |
559 | pwm = ERR_PTR(-EINVAL); | |
560 | goto put; | |
561 | } | |
562 | ||
563 | pwm = pc->of_xlate(pc, &args); | |
564 | if (IS_ERR(pwm)) | |
565 | goto put; | |
566 | ||
567 | /* | |
568 | * If a consumer name was not given, try to look it up from the | |
569 | * "pwm-names" property if it exists. Otherwise use the name of | |
570 | * the user device node. | |
571 | */ | |
572 | if (!con_id) { | |
573 | err = of_property_read_string_index(np, "pwm-names", index, | |
574 | &con_id); | |
575 | if (err < 0) | |
576 | con_id = np->name; | |
577 | } | |
578 | ||
579 | pwm->label = con_id; | |
580 | ||
581 | put: | |
582 | of_node_put(args.np); | |
583 | ||
584 | return pwm; | |
585 | } | |
8eb96127 | 586 | EXPORT_SYMBOL_GPL(of_pwm_get); |
7299ab70 | 587 | |
8138d2dd TR |
588 | /** |
589 | * pwm_add_table() - register PWM device consumers | |
590 | * @table: array of consumers to register | |
591 | * @num: number of consumers in table | |
592 | */ | |
c264f111 | 593 | void pwm_add_table(struct pwm_lookup *table, size_t num) |
8138d2dd TR |
594 | { |
595 | mutex_lock(&pwm_lookup_lock); | |
596 | ||
597 | while (num--) { | |
598 | list_add_tail(&table->list, &pwm_lookup_list); | |
599 | table++; | |
600 | } | |
601 | ||
602 | mutex_unlock(&pwm_lookup_lock); | |
603 | } | |
604 | ||
efb0de55 SK |
605 | /** |
606 | * pwm_remove_table() - unregister PWM device consumers | |
607 | * @table: array of consumers to unregister | |
608 | * @num: number of consumers in table | |
609 | */ | |
610 | void pwm_remove_table(struct pwm_lookup *table, size_t num) | |
611 | { | |
612 | mutex_lock(&pwm_lookup_lock); | |
613 | ||
614 | while (num--) { | |
615 | list_del(&table->list); | |
616 | table++; | |
617 | } | |
618 | ||
619 | mutex_unlock(&pwm_lookup_lock); | |
620 | } | |
621 | ||
8138d2dd TR |
622 | /** |
623 | * pwm_get() - look up and request a PWM device | |
624 | * @dev: device for PWM consumer | |
625 | * @con_id: consumer name | |
626 | * | |
7299ab70 TR |
627 | * Lookup is first attempted using DT. If the device was not instantiated from |
628 | * a device tree, a PWM chip and a relative index is looked up via a table | |
629 | * supplied by board setup code (see pwm_add_table()). | |
8138d2dd TR |
630 | * |
631 | * Once a PWM chip has been found the specified PWM device will be requested | |
632 | * and is ready to be used. | |
633 | */ | |
634 | struct pwm_device *pwm_get(struct device *dev, const char *con_id) | |
635 | { | |
636 | struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER); | |
e50d3523 | 637 | const char *dev_id = dev ? dev_name(dev) : NULL; |
8138d2dd TR |
638 | struct pwm_chip *chip = NULL; |
639 | unsigned int best = 0; | |
70145f87 | 640 | struct pwm_lookup *p, *chosen = NULL; |
8138d2dd TR |
641 | unsigned int match; |
642 | ||
7299ab70 TR |
643 | /* look up via DT first */ |
644 | if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) | |
8eb96127 | 645 | return of_pwm_get(dev->of_node, con_id); |
7299ab70 | 646 | |
8138d2dd TR |
647 | /* |
648 | * We look up the provider in the static table typically provided by | |
649 | * board setup code. We first try to lookup the consumer device by | |
650 | * name. If the consumer device was passed in as NULL or if no match | |
651 | * was found, we try to find the consumer by directly looking it up | |
652 | * by name. | |
653 | * | |
654 | * If a match is found, the provider PWM chip is looked up by name | |
655 | * and a PWM device is requested using the PWM device per-chip index. | |
656 | * | |
657 | * The lookup algorithm was shamelessly taken from the clock | |
658 | * framework: | |
659 | * | |
660 | * We do slightly fuzzy matching here: | |
661 | * An entry with a NULL ID is assumed to be a wildcard. | |
662 | * If an entry has a device ID, it must match | |
663 | * If an entry has a connection ID, it must match | |
664 | * Then we take the most specific entry - with the following order | |
665 | * of precedence: dev+con > dev only > con only. | |
666 | */ | |
667 | mutex_lock(&pwm_lookup_lock); | |
668 | ||
669 | list_for_each_entry(p, &pwm_lookup_list, list) { | |
670 | match = 0; | |
671 | ||
672 | if (p->dev_id) { | |
673 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
674 | continue; | |
675 | ||
676 | match += 2; | |
677 | } | |
678 | ||
679 | if (p->con_id) { | |
680 | if (!con_id || strcmp(p->con_id, con_id)) | |
681 | continue; | |
682 | ||
683 | match += 1; | |
684 | } | |
685 | ||
686 | if (match > best) { | |
70145f87 | 687 | chosen = p; |
8138d2dd TR |
688 | |
689 | if (match != 3) | |
690 | best = match; | |
691 | else | |
692 | break; | |
693 | } | |
694 | } | |
695 | ||
70145f87 GU |
696 | if (!chosen) |
697 | goto out; | |
3796ce1d | 698 | |
70145f87 GU |
699 | chip = pwmchip_find_by_name(chosen->provider); |
700 | if (!chip) | |
701 | goto out; | |
3796ce1d | 702 | |
70145f87 GU |
703 | pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id); |
704 | if (IS_ERR(pwm)) | |
705 | goto out; | |
8138d2dd | 706 | |
70145f87 GU |
707 | pwm_set_period(pwm, chosen->period); |
708 | pwm_set_polarity(pwm, chosen->polarity); | |
8138d2dd | 709 | |
70145f87 GU |
710 | out: |
711 | mutex_unlock(&pwm_lookup_lock); | |
8138d2dd TR |
712 | return pwm; |
713 | } | |
714 | EXPORT_SYMBOL_GPL(pwm_get); | |
715 | ||
716 | /** | |
717 | * pwm_put() - release a PWM device | |
718 | * @pwm: PWM device | |
719 | */ | |
720 | void pwm_put(struct pwm_device *pwm) | |
721 | { | |
722 | if (!pwm) | |
723 | return; | |
724 | ||
725 | mutex_lock(&pwm_lock); | |
726 | ||
727 | if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { | |
e50d3523 | 728 | pr_warn("PWM device already freed\n"); |
8138d2dd TR |
729 | goto out; |
730 | } | |
731 | ||
732 | if (pwm->chip->ops->free) | |
733 | pwm->chip->ops->free(pwm->chip, pwm); | |
734 | ||
735 | pwm->label = NULL; | |
736 | ||
737 | module_put(pwm->chip->ops->owner); | |
738 | out: | |
739 | mutex_unlock(&pwm_lock); | |
740 | } | |
741 | EXPORT_SYMBOL_GPL(pwm_put); | |
742 | ||
6354316d AC |
743 | static void devm_pwm_release(struct device *dev, void *res) |
744 | { | |
745 | pwm_put(*(struct pwm_device **)res); | |
746 | } | |
747 | ||
748 | /** | |
749 | * devm_pwm_get() - resource managed pwm_get() | |
750 | * @dev: device for PWM consumer | |
751 | * @con_id: consumer name | |
752 | * | |
753 | * This function performs like pwm_get() but the acquired PWM device will | |
754 | * automatically be released on driver detach. | |
755 | */ | |
756 | struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id) | |
757 | { | |
758 | struct pwm_device **ptr, *pwm; | |
759 | ||
77f0b9d2 | 760 | ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL); |
6354316d AC |
761 | if (!ptr) |
762 | return ERR_PTR(-ENOMEM); | |
763 | ||
764 | pwm = pwm_get(dev, con_id); | |
765 | if (!IS_ERR(pwm)) { | |
766 | *ptr = pwm; | |
767 | devres_add(dev, ptr); | |
768 | } else { | |
769 | devres_free(ptr); | |
770 | } | |
771 | ||
772 | return pwm; | |
773 | } | |
774 | EXPORT_SYMBOL_GPL(devm_pwm_get); | |
775 | ||
261a5edd PU |
776 | /** |
777 | * devm_of_pwm_get() - resource managed of_pwm_get() | |
778 | * @dev: device for PWM consumer | |
779 | * @np: device node to get the PWM from | |
780 | * @con_id: consumer name | |
781 | * | |
782 | * This function performs like of_pwm_get() but the acquired PWM device will | |
783 | * automatically be released on driver detach. | |
784 | */ | |
785 | struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, | |
786 | const char *con_id) | |
787 | { | |
788 | struct pwm_device **ptr, *pwm; | |
789 | ||
77f0b9d2 | 790 | ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL); |
261a5edd PU |
791 | if (!ptr) |
792 | return ERR_PTR(-ENOMEM); | |
793 | ||
794 | pwm = of_pwm_get(np, con_id); | |
795 | if (!IS_ERR(pwm)) { | |
796 | *ptr = pwm; | |
797 | devres_add(dev, ptr); | |
798 | } else { | |
799 | devres_free(ptr); | |
800 | } | |
801 | ||
802 | return pwm; | |
803 | } | |
804 | EXPORT_SYMBOL_GPL(devm_of_pwm_get); | |
805 | ||
6354316d AC |
806 | static int devm_pwm_match(struct device *dev, void *res, void *data) |
807 | { | |
808 | struct pwm_device **p = res; | |
809 | ||
810 | if (WARN_ON(!p || !*p)) | |
811 | return 0; | |
812 | ||
813 | return *p == data; | |
814 | } | |
815 | ||
816 | /** | |
817 | * devm_pwm_put() - resource managed pwm_put() | |
818 | * @dev: device for PWM consumer | |
819 | * @pwm: PWM device | |
820 | * | |
821 | * Release a PWM previously allocated using devm_pwm_get(). Calling this | |
822 | * function is usually not needed because devm-allocated resources are | |
823 | * automatically released on driver detach. | |
824 | */ | |
825 | void devm_pwm_put(struct device *dev, struct pwm_device *pwm) | |
826 | { | |
827 | WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm)); | |
828 | } | |
829 | EXPORT_SYMBOL_GPL(devm_pwm_put); | |
830 | ||
6e69ab13 FV |
831 | /** |
832 | * pwm_can_sleep() - report whether PWM access will sleep | |
833 | * @pwm: PWM device | |
834 | * | |
835 | * It returns true if accessing the PWM can sleep, false otherwise. | |
836 | */ | |
837 | bool pwm_can_sleep(struct pwm_device *pwm) | |
838 | { | |
839 | return pwm->chip->can_sleep; | |
840 | } | |
841 | EXPORT_SYMBOL_GPL(pwm_can_sleep); | |
842 | ||
62099abf TR |
843 | #ifdef CONFIG_DEBUG_FS |
844 | static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) | |
845 | { | |
846 | unsigned int i; | |
847 | ||
848 | for (i = 0; i < chip->npwm; i++) { | |
849 | struct pwm_device *pwm = &chip->pwms[i]; | |
850 | ||
851 | seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); | |
852 | ||
853 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
adcba1e3 | 854 | seq_puts(s, " requested"); |
62099abf TR |
855 | |
856 | if (test_bit(PWMF_ENABLED, &pwm->flags)) | |
adcba1e3 | 857 | seq_puts(s, " enabled"); |
62099abf | 858 | |
adcba1e3 | 859 | seq_puts(s, "\n"); |
62099abf TR |
860 | } |
861 | } | |
862 | ||
863 | static void *pwm_seq_start(struct seq_file *s, loff_t *pos) | |
864 | { | |
865 | mutex_lock(&pwm_lock); | |
866 | s->private = ""; | |
867 | ||
868 | return seq_list_start(&pwm_chips, *pos); | |
869 | } | |
870 | ||
871 | static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
872 | { | |
873 | s->private = "\n"; | |
874 | ||
875 | return seq_list_next(v, &pwm_chips, pos); | |
876 | } | |
877 | ||
878 | static void pwm_seq_stop(struct seq_file *s, void *v) | |
879 | { | |
880 | mutex_unlock(&pwm_lock); | |
881 | } | |
882 | ||
883 | static int pwm_seq_show(struct seq_file *s, void *v) | |
884 | { | |
885 | struct pwm_chip *chip = list_entry(v, struct pwm_chip, list); | |
886 | ||
887 | seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private, | |
888 | chip->dev->bus ? chip->dev->bus->name : "no-bus", | |
889 | dev_name(chip->dev), chip->npwm, | |
890 | (chip->npwm != 1) ? "s" : ""); | |
891 | ||
892 | if (chip->ops->dbg_show) | |
893 | chip->ops->dbg_show(chip, s); | |
894 | else | |
895 | pwm_dbg_show(chip, s); | |
896 | ||
897 | return 0; | |
898 | } | |
899 | ||
900 | static const struct seq_operations pwm_seq_ops = { | |
901 | .start = pwm_seq_start, | |
902 | .next = pwm_seq_next, | |
903 | .stop = pwm_seq_stop, | |
904 | .show = pwm_seq_show, | |
905 | }; | |
906 | ||
907 | static int pwm_seq_open(struct inode *inode, struct file *file) | |
908 | { | |
909 | return seq_open(file, &pwm_seq_ops); | |
910 | } | |
911 | ||
912 | static const struct file_operations pwm_debugfs_ops = { | |
913 | .owner = THIS_MODULE, | |
914 | .open = pwm_seq_open, | |
915 | .read = seq_read, | |
916 | .llseek = seq_lseek, | |
917 | .release = seq_release, | |
918 | }; | |
919 | ||
920 | static int __init pwm_debugfs_init(void) | |
921 | { | |
922 | debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL, | |
923 | &pwm_debugfs_ops); | |
924 | ||
925 | return 0; | |
926 | } | |
927 | ||
928 | subsys_initcall(pwm_debugfs_init); | |
929 | #endif /* CONFIG_DEBUG_FS */ |