Commit | Line | Data |
---|---|---|
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 | |
f051c466 | 33 | #define MAX_PWMS 1024 |
0c2498f1 | 34 | |
83af2402 PA |
35 | /* flags in the third cell of the DT PWM specifier */ |
36 | #define PWM_SPEC_POLARITY (1 << 0) | |
37 | ||
8138d2dd TR |
38 | static DEFINE_MUTEX(pwm_lookup_lock); |
39 | static LIST_HEAD(pwm_lookup_list); | |
0c2498f1 | 40 | static DEFINE_MUTEX(pwm_lock); |
f051c466 TR |
41 | static LIST_HEAD(pwm_chips); |
42 | static DECLARE_BITMAP(allocated_pwms, MAX_PWMS); | |
43 | static RADIX_TREE(pwm_tree, GFP_KERNEL); | |
0c2498f1 | 44 | |
f051c466 | 45 | static struct pwm_device *pwm_to_device(unsigned int pwm) |
0c2498f1 | 46 | { |
f051c466 TR |
47 | return radix_tree_lookup(&pwm_tree, pwm); |
48 | } | |
49 | ||
50 | static int alloc_pwms(int pwm, unsigned int count) | |
51 | { | |
52 | unsigned int from = 0; | |
53 | unsigned int start; | |
54 | ||
55 | if (pwm >= MAX_PWMS) | |
56 | return -EINVAL; | |
57 | ||
58 | if (pwm >= 0) | |
59 | from = pwm; | |
0c2498f1 | 60 | |
f051c466 TR |
61 | start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from, |
62 | count, 0); | |
63 | ||
64 | if (pwm >= 0 && start != pwm) | |
65 | return -EEXIST; | |
66 | ||
67 | if (start + count > MAX_PWMS) | |
68 | return -ENOSPC; | |
69 | ||
70 | return start; | |
71 | } | |
72 | ||
73 | static void free_pwms(struct pwm_chip *chip) | |
74 | { | |
75 | unsigned int i; | |
76 | ||
77 | for (i = 0; i < chip->npwm; i++) { | |
78 | struct pwm_device *pwm = &chip->pwms[i]; | |
79 | radix_tree_delete(&pwm_tree, pwm->pwm); | |
0c2498f1 SH |
80 | } |
81 | ||
f051c466 TR |
82 | bitmap_clear(allocated_pwms, chip->base, chip->npwm); |
83 | ||
84 | kfree(chip->pwms); | |
85 | chip->pwms = NULL; | |
86 | } | |
87 | ||
8138d2dd TR |
88 | static struct pwm_chip *pwmchip_find_by_name(const char *name) |
89 | { | |
90 | struct pwm_chip *chip; | |
91 | ||
92 | if (!name) | |
93 | return NULL; | |
94 | ||
95 | mutex_lock(&pwm_lock); | |
96 | ||
97 | list_for_each_entry(chip, &pwm_chips, list) { | |
98 | const char *chip_name = dev_name(chip->dev); | |
99 | ||
100 | if (chip_name && strcmp(chip_name, name) == 0) { | |
101 | mutex_unlock(&pwm_lock); | |
102 | return chip; | |
103 | } | |
104 | } | |
105 | ||
106 | mutex_unlock(&pwm_lock); | |
107 | ||
108 | return NULL; | |
109 | } | |
110 | ||
f051c466 TR |
111 | static int pwm_device_request(struct pwm_device *pwm, const char *label) |
112 | { | |
113 | int err; | |
114 | ||
115 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
116 | return -EBUSY; | |
117 | ||
118 | if (!try_module_get(pwm->chip->ops->owner)) | |
119 | return -ENODEV; | |
120 | ||
121 | if (pwm->chip->ops->request) { | |
122 | err = pwm->chip->ops->request(pwm->chip, pwm); | |
123 | if (err) { | |
124 | module_put(pwm->chip->ops->owner); | |
125 | return err; | |
126 | } | |
127 | } | |
128 | ||
129 | set_bit(PWMF_REQUESTED, &pwm->flags); | |
130 | pwm->label = label; | |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
83af2402 PA |
135 | struct pwm_device * |
136 | of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) | |
137 | { | |
138 | struct pwm_device *pwm; | |
139 | ||
140 | if (pc->of_pwm_n_cells < 3) | |
141 | return ERR_PTR(-EINVAL); | |
142 | ||
143 | if (args->args[0] >= pc->npwm) | |
144 | return ERR_PTR(-EINVAL); | |
145 | ||
146 | pwm = pwm_request_from_chip(pc, args->args[0], NULL); | |
147 | if (IS_ERR(pwm)) | |
148 | return pwm; | |
149 | ||
150 | pwm_set_period(pwm, args->args[1]); | |
151 | ||
152 | if (args->args[2] & PWM_SPEC_POLARITY) | |
153 | pwm_set_polarity(pwm, PWM_POLARITY_INVERSED); | |
154 | else | |
155 | pwm_set_polarity(pwm, PWM_POLARITY_NORMAL); | |
156 | ||
157 | return pwm; | |
158 | } | |
417328c3 | 159 | EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags); |
83af2402 | 160 | |
e50d3523 SK |
161 | static struct pwm_device * |
162 | of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) | |
7299ab70 TR |
163 | { |
164 | struct pwm_device *pwm; | |
165 | ||
166 | if (pc->of_pwm_n_cells < 2) | |
167 | return ERR_PTR(-EINVAL); | |
168 | ||
169 | if (args->args[0] >= pc->npwm) | |
170 | return ERR_PTR(-EINVAL); | |
171 | ||
172 | pwm = pwm_request_from_chip(pc, args->args[0], NULL); | |
173 | if (IS_ERR(pwm)) | |
174 | return pwm; | |
175 | ||
176 | pwm_set_period(pwm, args->args[1]); | |
177 | ||
178 | return pwm; | |
179 | } | |
180 | ||
dfeb86ec | 181 | static void of_pwmchip_add(struct pwm_chip *chip) |
7299ab70 TR |
182 | { |
183 | if (!chip->dev || !chip->dev->of_node) | |
184 | return; | |
185 | ||
186 | if (!chip->of_xlate) { | |
187 | chip->of_xlate = of_pwm_simple_xlate; | |
188 | chip->of_pwm_n_cells = 2; | |
189 | } | |
190 | ||
191 | of_node_get(chip->dev->of_node); | |
192 | } | |
193 | ||
dfeb86ec | 194 | static void of_pwmchip_remove(struct pwm_chip *chip) |
7299ab70 TR |
195 | { |
196 | if (chip->dev && chip->dev->of_node) | |
197 | of_node_put(chip->dev->of_node); | |
198 | } | |
199 | ||
f051c466 TR |
200 | /** |
201 | * pwm_set_chip_data() - set private chip data for a PWM | |
202 | * @pwm: PWM device | |
203 | * @data: pointer to chip-specific data | |
204 | */ | |
205 | int pwm_set_chip_data(struct pwm_device *pwm, void *data) | |
206 | { | |
207 | if (!pwm) | |
208 | return -EINVAL; | |
209 | ||
210 | pwm->chip_data = data; | |
211 | ||
212 | return 0; | |
213 | } | |
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 SH |
222 | } |
223 | ||
224 | /** | |
225 | * pwmchip_add() - register a new PWM chip | |
226 | * @chip: the PWM chip to add | |
f051c466 TR |
227 | * |
228 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base | |
229 | * will be used. | |
0c2498f1 SH |
230 | */ |
231 | int pwmchip_add(struct pwm_chip *chip) | |
232 | { | |
233 | struct pwm_device *pwm; | |
f051c466 TR |
234 | unsigned int i; |
235 | int ret; | |
0c2498f1 | 236 | |
f051c466 TR |
237 | if (!chip || !chip->dev || !chip->ops || !chip->ops->config || |
238 | !chip->ops->enable || !chip->ops->disable) | |
239 | return -EINVAL; | |
0c2498f1 SH |
240 | |
241 | mutex_lock(&pwm_lock); | |
242 | ||
f051c466 TR |
243 | ret = alloc_pwms(chip->base, chip->npwm); |
244 | if (ret < 0) | |
245 | goto out; | |
246 | ||
247 | chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL); | |
248 | if (!chip->pwms) { | |
249 | ret = -ENOMEM; | |
0c2498f1 SH |
250 | goto out; |
251 | } | |
252 | ||
f051c466 TR |
253 | chip->base = ret; |
254 | ||
255 | for (i = 0; i < chip->npwm; i++) { | |
256 | pwm = &chip->pwms[i]; | |
257 | ||
258 | pwm->chip = chip; | |
259 | pwm->pwm = chip->base + i; | |
260 | pwm->hwpwm = i; | |
0c2498f1 | 261 | |
f051c466 TR |
262 | radix_tree_insert(&pwm_tree, pwm->pwm, pwm); |
263 | } | |
264 | ||
265 | bitmap_set(allocated_pwms, chip->base, chip->npwm); | |
266 | ||
267 | INIT_LIST_HEAD(&chip->list); | |
268 | list_add(&chip->list, &pwm_chips); | |
0c2498f1 | 269 | |
f051c466 TR |
270 | ret = 0; |
271 | ||
7299ab70 TR |
272 | if (IS_ENABLED(CONFIG_OF)) |
273 | of_pwmchip_add(chip); | |
274 | ||
f051c466 TR |
275 | out: |
276 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
277 | return ret; |
278 | } | |
279 | EXPORT_SYMBOL_GPL(pwmchip_add); | |
280 | ||
281 | /** | |
282 | * pwmchip_remove() - remove a PWM chip | |
283 | * @chip: the PWM chip to remove | |
284 | * | |
285 | * Removes a PWM chip. This function may return busy if the PWM chip provides | |
286 | * a PWM device that is still requested. | |
287 | */ | |
288 | int pwmchip_remove(struct pwm_chip *chip) | |
289 | { | |
f051c466 | 290 | unsigned int i; |
0c2498f1 SH |
291 | int ret = 0; |
292 | ||
293 | mutex_lock(&pwm_lock); | |
294 | ||
f051c466 TR |
295 | for (i = 0; i < chip->npwm; i++) { |
296 | struct pwm_device *pwm = &chip->pwms[i]; | |
0c2498f1 | 297 | |
f051c466 TR |
298 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) { |
299 | ret = -EBUSY; | |
300 | goto out; | |
301 | } | |
0c2498f1 SH |
302 | } |
303 | ||
f051c466 | 304 | list_del_init(&chip->list); |
7299ab70 TR |
305 | |
306 | if (IS_ENABLED(CONFIG_OF)) | |
307 | of_pwmchip_remove(chip); | |
308 | ||
f051c466 | 309 | free_pwms(chip); |
0c2498f1 | 310 | |
0c2498f1 SH |
311 | out: |
312 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
313 | return ret; |
314 | } | |
315 | EXPORT_SYMBOL_GPL(pwmchip_remove); | |
316 | ||
317 | /** | |
318 | * pwm_request() - request a PWM device | |
319 | * @pwm_id: global PWM device index | |
320 | * @label: PWM device label | |
8138d2dd TR |
321 | * |
322 | * This function is deprecated, use pwm_get() instead. | |
0c2498f1 | 323 | */ |
f051c466 | 324 | struct pwm_device *pwm_request(int pwm, const char *label) |
0c2498f1 | 325 | { |
f051c466 TR |
326 | struct pwm_device *dev; |
327 | int err; | |
328 | ||
329 | if (pwm < 0 || pwm >= MAX_PWMS) | |
330 | return ERR_PTR(-EINVAL); | |
0c2498f1 SH |
331 | |
332 | mutex_lock(&pwm_lock); | |
333 | ||
f051c466 TR |
334 | dev = pwm_to_device(pwm); |
335 | if (!dev) { | |
336 | dev = ERR_PTR(-EPROBE_DEFER); | |
0c2498f1 SH |
337 | goto out; |
338 | } | |
339 | ||
f051c466 TR |
340 | err = pwm_device_request(dev, label); |
341 | if (err < 0) | |
342 | dev = ERR_PTR(err); | |
0c2498f1 | 343 | |
f051c466 TR |
344 | out: |
345 | mutex_unlock(&pwm_lock); | |
0c2498f1 | 346 | |
f051c466 TR |
347 | return dev; |
348 | } | |
349 | EXPORT_SYMBOL_GPL(pwm_request); | |
0c2498f1 | 350 | |
f051c466 TR |
351 | /** |
352 | * pwm_request_from_chip() - request a PWM device relative to a PWM chip | |
353 | * @chip: PWM chip | |
354 | * @index: per-chip index of the PWM to request | |
355 | * @label: a literal description string of this PWM | |
356 | * | |
357 | * Returns the PWM at the given index of the given PWM chip. A negative error | |
358 | * code is returned if the index is not valid for the specified PWM chip or | |
359 | * if the PWM device cannot be requested. | |
360 | */ | |
361 | struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, | |
362 | unsigned int index, | |
363 | const char *label) | |
364 | { | |
365 | struct pwm_device *pwm; | |
366 | int err; | |
0c2498f1 | 367 | |
f051c466 TR |
368 | if (!chip || index >= chip->npwm) |
369 | return ERR_PTR(-EINVAL); | |
0c2498f1 | 370 | |
f051c466 TR |
371 | mutex_lock(&pwm_lock); |
372 | pwm = &chip->pwms[index]; | |
0c2498f1 | 373 | |
f051c466 TR |
374 | err = pwm_device_request(pwm, label); |
375 | if (err < 0) | |
376 | pwm = ERR_PTR(err); | |
377 | ||
378 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
379 | return pwm; |
380 | } | |
f051c466 | 381 | EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
0c2498f1 SH |
382 | |
383 | /** | |
384 | * pwm_free() - free a PWM device | |
385 | * @pwm: PWM device | |
8138d2dd TR |
386 | * |
387 | * This function is deprecated, use pwm_put() instead. | |
0c2498f1 SH |
388 | */ |
389 | void pwm_free(struct pwm_device *pwm) | |
390 | { | |
8138d2dd | 391 | pwm_put(pwm); |
0c2498f1 SH |
392 | } |
393 | EXPORT_SYMBOL_GPL(pwm_free); | |
394 | ||
395 | /** | |
396 | * pwm_config() - change a PWM device configuration | |
397 | * @pwm: PWM device | |
398 | * @duty_ns: "on" time (in nanoseconds) | |
399 | * @period_ns: duration (in nanoseconds) of one cycle | |
400 | */ | |
401 | int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) | |
402 | { | |
c2d476a9 | 403 | if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns) |
f051c466 TR |
404 | return -EINVAL; |
405 | ||
406 | return pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); | |
0c2498f1 SH |
407 | } |
408 | EXPORT_SYMBOL_GPL(pwm_config); | |
409 | ||
0aa0869c PA |
410 | /** |
411 | * pwm_set_polarity() - configure the polarity of a PWM signal | |
412 | * @pwm: PWM device | |
413 | * @polarity: new polarity of the PWM signal | |
414 | * | |
415 | * Note that the polarity cannot be configured while the PWM device is enabled | |
416 | */ | |
417 | int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) | |
418 | { | |
419 | if (!pwm || !pwm->chip->ops) | |
420 | return -EINVAL; | |
421 | ||
422 | if (!pwm->chip->ops->set_polarity) | |
423 | return -ENOSYS; | |
424 | ||
425 | if (test_bit(PWMF_ENABLED, &pwm->flags)) | |
426 | return -EBUSY; | |
427 | ||
428 | return pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity); | |
429 | } | |
430 | EXPORT_SYMBOL_GPL(pwm_set_polarity); | |
431 | ||
0c2498f1 SH |
432 | /** |
433 | * pwm_enable() - start a PWM output toggling | |
434 | * @pwm: PWM device | |
435 | */ | |
436 | int pwm_enable(struct pwm_device *pwm) | |
437 | { | |
f051c466 TR |
438 | if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags)) |
439 | return pwm->chip->ops->enable(pwm->chip, pwm); | |
0c2498f1 | 440 | |
f051c466 | 441 | return pwm ? 0 : -EINVAL; |
0c2498f1 SH |
442 | } |
443 | EXPORT_SYMBOL_GPL(pwm_enable); | |
444 | ||
445 | /** | |
446 | * pwm_disable() - stop a PWM output toggling | |
447 | * @pwm: PWM device | |
448 | */ | |
449 | void pwm_disable(struct pwm_device *pwm) | |
450 | { | |
f051c466 TR |
451 | if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags)) |
452 | pwm->chip->ops->disable(pwm->chip, pwm); | |
0c2498f1 SH |
453 | } |
454 | EXPORT_SYMBOL_GPL(pwm_disable); | |
62099abf | 455 | |
7299ab70 TR |
456 | static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) |
457 | { | |
458 | struct pwm_chip *chip; | |
459 | ||
460 | mutex_lock(&pwm_lock); | |
461 | ||
462 | list_for_each_entry(chip, &pwm_chips, list) | |
463 | if (chip->dev && chip->dev->of_node == np) { | |
464 | mutex_unlock(&pwm_lock); | |
465 | return chip; | |
466 | } | |
467 | ||
468 | mutex_unlock(&pwm_lock); | |
469 | ||
470 | return ERR_PTR(-EPROBE_DEFER); | |
471 | } | |
472 | ||
473 | /** | |
8eb96127 | 474 | * of_pwm_get() - request a PWM via the PWM framework |
7299ab70 TR |
475 | * @np: device node to get the PWM from |
476 | * @con_id: consumer name | |
477 | * | |
478 | * Returns the PWM device parsed from the phandle and index specified in the | |
479 | * "pwms" property of a device tree node or a negative error-code on failure. | |
480 | * Values parsed from the device tree are stored in the returned PWM device | |
481 | * object. | |
482 | * | |
483 | * If con_id is NULL, the first PWM device listed in the "pwms" property will | |
484 | * be requested. Otherwise the "pwm-names" property is used to do a reverse | |
485 | * lookup of the PWM index. This also means that the "pwm-names" property | |
486 | * becomes mandatory for devices that look up the PWM device via the con_id | |
487 | * parameter. | |
488 | */ | |
8eb96127 | 489 | struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) |
7299ab70 TR |
490 | { |
491 | struct pwm_device *pwm = NULL; | |
492 | struct of_phandle_args args; | |
493 | struct pwm_chip *pc; | |
494 | int index = 0; | |
495 | int err; | |
496 | ||
497 | if (con_id) { | |
498 | index = of_property_match_string(np, "pwm-names", con_id); | |
499 | if (index < 0) | |
500 | return ERR_PTR(index); | |
501 | } | |
502 | ||
503 | err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, | |
504 | &args); | |
505 | if (err) { | |
506 | pr_debug("%s(): can't parse \"pwms\" property\n", __func__); | |
507 | return ERR_PTR(err); | |
508 | } | |
509 | ||
510 | pc = of_node_to_pwmchip(args.np); | |
511 | if (IS_ERR(pc)) { | |
512 | pr_debug("%s(): PWM chip not found\n", __func__); | |
513 | pwm = ERR_CAST(pc); | |
514 | goto put; | |
515 | } | |
516 | ||
517 | if (args.args_count != pc->of_pwm_n_cells) { | |
518 | pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name, | |
519 | args.np->full_name); | |
520 | pwm = ERR_PTR(-EINVAL); | |
521 | goto put; | |
522 | } | |
523 | ||
524 | pwm = pc->of_xlate(pc, &args); | |
525 | if (IS_ERR(pwm)) | |
526 | goto put; | |
527 | ||
528 | /* | |
529 | * If a consumer name was not given, try to look it up from the | |
530 | * "pwm-names" property if it exists. Otherwise use the name of | |
531 | * the user device node. | |
532 | */ | |
533 | if (!con_id) { | |
534 | err = of_property_read_string_index(np, "pwm-names", index, | |
535 | &con_id); | |
536 | if (err < 0) | |
537 | con_id = np->name; | |
538 | } | |
539 | ||
540 | pwm->label = con_id; | |
541 | ||
542 | put: | |
543 | of_node_put(args.np); | |
544 | ||
545 | return pwm; | |
546 | } | |
8eb96127 | 547 | EXPORT_SYMBOL_GPL(of_pwm_get); |
7299ab70 | 548 | |
8138d2dd TR |
549 | /** |
550 | * pwm_add_table() - register PWM device consumers | |
551 | * @table: array of consumers to register | |
552 | * @num: number of consumers in table | |
553 | */ | |
554 | void __init pwm_add_table(struct pwm_lookup *table, size_t num) | |
555 | { | |
556 | mutex_lock(&pwm_lookup_lock); | |
557 | ||
558 | while (num--) { | |
559 | list_add_tail(&table->list, &pwm_lookup_list); | |
560 | table++; | |
561 | } | |
562 | ||
563 | mutex_unlock(&pwm_lookup_lock); | |
564 | } | |
565 | ||
566 | /** | |
567 | * pwm_get() - look up and request a PWM device | |
568 | * @dev: device for PWM consumer | |
569 | * @con_id: consumer name | |
570 | * | |
7299ab70 TR |
571 | * Lookup is first attempted using DT. If the device was not instantiated from |
572 | * a device tree, a PWM chip and a relative index is looked up via a table | |
573 | * supplied by board setup code (see pwm_add_table()). | |
8138d2dd TR |
574 | * |
575 | * Once a PWM chip has been found the specified PWM device will be requested | |
576 | * and is ready to be used. | |
577 | */ | |
578 | struct pwm_device *pwm_get(struct device *dev, const char *con_id) | |
579 | { | |
580 | struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER); | |
e50d3523 | 581 | const char *dev_id = dev ? dev_name(dev) : NULL; |
8138d2dd | 582 | struct pwm_chip *chip = NULL; |
d295b129 | 583 | unsigned int index = 0; |
8138d2dd TR |
584 | unsigned int best = 0; |
585 | struct pwm_lookup *p; | |
8138d2dd TR |
586 | unsigned int match; |
587 | ||
7299ab70 TR |
588 | /* look up via DT first */ |
589 | if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) | |
8eb96127 | 590 | return of_pwm_get(dev->of_node, con_id); |
7299ab70 | 591 | |
8138d2dd TR |
592 | /* |
593 | * We look up the provider in the static table typically provided by | |
594 | * board setup code. We first try to lookup the consumer device by | |
595 | * name. If the consumer device was passed in as NULL or if no match | |
596 | * was found, we try to find the consumer by directly looking it up | |
597 | * by name. | |
598 | * | |
599 | * If a match is found, the provider PWM chip is looked up by name | |
600 | * and a PWM device is requested using the PWM device per-chip index. | |
601 | * | |
602 | * The lookup algorithm was shamelessly taken from the clock | |
603 | * framework: | |
604 | * | |
605 | * We do slightly fuzzy matching here: | |
606 | * An entry with a NULL ID is assumed to be a wildcard. | |
607 | * If an entry has a device ID, it must match | |
608 | * If an entry has a connection ID, it must match | |
609 | * Then we take the most specific entry - with the following order | |
610 | * of precedence: dev+con > dev only > con only. | |
611 | */ | |
612 | mutex_lock(&pwm_lookup_lock); | |
613 | ||
614 | list_for_each_entry(p, &pwm_lookup_list, list) { | |
615 | match = 0; | |
616 | ||
617 | if (p->dev_id) { | |
618 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
619 | continue; | |
620 | ||
621 | match += 2; | |
622 | } | |
623 | ||
624 | if (p->con_id) { | |
625 | if (!con_id || strcmp(p->con_id, con_id)) | |
626 | continue; | |
627 | ||
628 | match += 1; | |
629 | } | |
630 | ||
631 | if (match > best) { | |
632 | chip = pwmchip_find_by_name(p->provider); | |
633 | index = p->index; | |
634 | ||
635 | if (match != 3) | |
636 | best = match; | |
637 | else | |
638 | break; | |
639 | } | |
640 | } | |
641 | ||
642 | if (chip) | |
643 | pwm = pwm_request_from_chip(chip, index, con_id ?: dev_id); | |
644 | ||
645 | mutex_unlock(&pwm_lookup_lock); | |
646 | ||
647 | return pwm; | |
648 | } | |
649 | EXPORT_SYMBOL_GPL(pwm_get); | |
650 | ||
651 | /** | |
652 | * pwm_put() - release a PWM device | |
653 | * @pwm: PWM device | |
654 | */ | |
655 | void pwm_put(struct pwm_device *pwm) | |
656 | { | |
657 | if (!pwm) | |
658 | return; | |
659 | ||
660 | mutex_lock(&pwm_lock); | |
661 | ||
662 | if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { | |
e50d3523 | 663 | pr_warn("PWM device already freed\n"); |
8138d2dd TR |
664 | goto out; |
665 | } | |
666 | ||
667 | if (pwm->chip->ops->free) | |
668 | pwm->chip->ops->free(pwm->chip, pwm); | |
669 | ||
670 | pwm->label = NULL; | |
671 | ||
672 | module_put(pwm->chip->ops->owner); | |
673 | out: | |
674 | mutex_unlock(&pwm_lock); | |
675 | } | |
676 | EXPORT_SYMBOL_GPL(pwm_put); | |
677 | ||
6354316d AC |
678 | static void devm_pwm_release(struct device *dev, void *res) |
679 | { | |
680 | pwm_put(*(struct pwm_device **)res); | |
681 | } | |
682 | ||
683 | /** | |
684 | * devm_pwm_get() - resource managed pwm_get() | |
685 | * @dev: device for PWM consumer | |
686 | * @con_id: consumer name | |
687 | * | |
688 | * This function performs like pwm_get() but the acquired PWM device will | |
689 | * automatically be released on driver detach. | |
690 | */ | |
691 | struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id) | |
692 | { | |
693 | struct pwm_device **ptr, *pwm; | |
694 | ||
695 | ptr = devres_alloc(devm_pwm_release, sizeof(**ptr), GFP_KERNEL); | |
696 | if (!ptr) | |
697 | return ERR_PTR(-ENOMEM); | |
698 | ||
699 | pwm = pwm_get(dev, con_id); | |
700 | if (!IS_ERR(pwm)) { | |
701 | *ptr = pwm; | |
702 | devres_add(dev, ptr); | |
703 | } else { | |
704 | devres_free(ptr); | |
705 | } | |
706 | ||
707 | return pwm; | |
708 | } | |
709 | EXPORT_SYMBOL_GPL(devm_pwm_get); | |
710 | ||
711 | static int devm_pwm_match(struct device *dev, void *res, void *data) | |
712 | { | |
713 | struct pwm_device **p = res; | |
714 | ||
715 | if (WARN_ON(!p || !*p)) | |
716 | return 0; | |
717 | ||
718 | return *p == data; | |
719 | } | |
720 | ||
721 | /** | |
722 | * devm_pwm_put() - resource managed pwm_put() | |
723 | * @dev: device for PWM consumer | |
724 | * @pwm: PWM device | |
725 | * | |
726 | * Release a PWM previously allocated using devm_pwm_get(). Calling this | |
727 | * function is usually not needed because devm-allocated resources are | |
728 | * automatically released on driver detach. | |
729 | */ | |
730 | void devm_pwm_put(struct device *dev, struct pwm_device *pwm) | |
731 | { | |
732 | WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm)); | |
733 | } | |
734 | EXPORT_SYMBOL_GPL(devm_pwm_put); | |
735 | ||
62099abf TR |
736 | #ifdef CONFIG_DEBUG_FS |
737 | static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) | |
738 | { | |
739 | unsigned int i; | |
740 | ||
741 | for (i = 0; i < chip->npwm; i++) { | |
742 | struct pwm_device *pwm = &chip->pwms[i]; | |
743 | ||
744 | seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); | |
745 | ||
746 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
747 | seq_printf(s, " requested"); | |
748 | ||
749 | if (test_bit(PWMF_ENABLED, &pwm->flags)) | |
750 | seq_printf(s, " enabled"); | |
751 | ||
752 | seq_printf(s, "\n"); | |
753 | } | |
754 | } | |
755 | ||
756 | static void *pwm_seq_start(struct seq_file *s, loff_t *pos) | |
757 | { | |
758 | mutex_lock(&pwm_lock); | |
759 | s->private = ""; | |
760 | ||
761 | return seq_list_start(&pwm_chips, *pos); | |
762 | } | |
763 | ||
764 | static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
765 | { | |
766 | s->private = "\n"; | |
767 | ||
768 | return seq_list_next(v, &pwm_chips, pos); | |
769 | } | |
770 | ||
771 | static void pwm_seq_stop(struct seq_file *s, void *v) | |
772 | { | |
773 | mutex_unlock(&pwm_lock); | |
774 | } | |
775 | ||
776 | static int pwm_seq_show(struct seq_file *s, void *v) | |
777 | { | |
778 | struct pwm_chip *chip = list_entry(v, struct pwm_chip, list); | |
779 | ||
780 | seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private, | |
781 | chip->dev->bus ? chip->dev->bus->name : "no-bus", | |
782 | dev_name(chip->dev), chip->npwm, | |
783 | (chip->npwm != 1) ? "s" : ""); | |
784 | ||
785 | if (chip->ops->dbg_show) | |
786 | chip->ops->dbg_show(chip, s); | |
787 | else | |
788 | pwm_dbg_show(chip, s); | |
789 | ||
790 | return 0; | |
791 | } | |
792 | ||
793 | static const struct seq_operations pwm_seq_ops = { | |
794 | .start = pwm_seq_start, | |
795 | .next = pwm_seq_next, | |
796 | .stop = pwm_seq_stop, | |
797 | .show = pwm_seq_show, | |
798 | }; | |
799 | ||
800 | static int pwm_seq_open(struct inode *inode, struct file *file) | |
801 | { | |
802 | return seq_open(file, &pwm_seq_ops); | |
803 | } | |
804 | ||
805 | static const struct file_operations pwm_debugfs_ops = { | |
806 | .owner = THIS_MODULE, | |
807 | .open = pwm_seq_open, | |
808 | .read = seq_read, | |
809 | .llseek = seq_lseek, | |
810 | .release = seq_release, | |
811 | }; | |
812 | ||
813 | static int __init pwm_debugfs_init(void) | |
814 | { | |
815 | debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL, | |
816 | &pwm_debugfs_ops); | |
817 | ||
818 | return 0; | |
819 | } | |
820 | ||
821 | subsys_initcall(pwm_debugfs_init); | |
822 | #endif /* CONFIG_DEBUG_FS */ |