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 | |
8138d2dd TR |
35 | static DEFINE_MUTEX(pwm_lookup_lock); |
36 | static LIST_HEAD(pwm_lookup_list); | |
0c2498f1 | 37 | static DEFINE_MUTEX(pwm_lock); |
f051c466 TR |
38 | static LIST_HEAD(pwm_chips); |
39 | static DECLARE_BITMAP(allocated_pwms, MAX_PWMS); | |
40 | static RADIX_TREE(pwm_tree, GFP_KERNEL); | |
0c2498f1 | 41 | |
f051c466 | 42 | static struct pwm_device *pwm_to_device(unsigned int pwm) |
0c2498f1 | 43 | { |
f051c466 TR |
44 | return radix_tree_lookup(&pwm_tree, pwm); |
45 | } | |
46 | ||
47 | static int alloc_pwms(int pwm, unsigned int count) | |
48 | { | |
49 | unsigned int from = 0; | |
50 | unsigned int start; | |
51 | ||
52 | if (pwm >= MAX_PWMS) | |
53 | return -EINVAL; | |
54 | ||
55 | if (pwm >= 0) | |
56 | from = pwm; | |
0c2498f1 | 57 | |
f051c466 TR |
58 | start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from, |
59 | count, 0); | |
60 | ||
61 | if (pwm >= 0 && start != pwm) | |
62 | return -EEXIST; | |
63 | ||
64 | if (start + count > MAX_PWMS) | |
65 | return -ENOSPC; | |
66 | ||
67 | return start; | |
68 | } | |
69 | ||
70 | static void free_pwms(struct pwm_chip *chip) | |
71 | { | |
72 | unsigned int i; | |
73 | ||
74 | for (i = 0; i < chip->npwm; i++) { | |
75 | struct pwm_device *pwm = &chip->pwms[i]; | |
76 | radix_tree_delete(&pwm_tree, pwm->pwm); | |
0c2498f1 SH |
77 | } |
78 | ||
f051c466 TR |
79 | bitmap_clear(allocated_pwms, chip->base, chip->npwm); |
80 | ||
81 | kfree(chip->pwms); | |
82 | chip->pwms = NULL; | |
83 | } | |
84 | ||
8138d2dd TR |
85 | static struct pwm_chip *pwmchip_find_by_name(const char *name) |
86 | { | |
87 | struct pwm_chip *chip; | |
88 | ||
89 | if (!name) | |
90 | return NULL; | |
91 | ||
92 | mutex_lock(&pwm_lock); | |
93 | ||
94 | list_for_each_entry(chip, &pwm_chips, list) { | |
95 | const char *chip_name = dev_name(chip->dev); | |
96 | ||
97 | if (chip_name && strcmp(chip_name, name) == 0) { | |
98 | mutex_unlock(&pwm_lock); | |
99 | return chip; | |
100 | } | |
101 | } | |
102 | ||
103 | mutex_unlock(&pwm_lock); | |
104 | ||
105 | return NULL; | |
106 | } | |
107 | ||
f051c466 TR |
108 | static int pwm_device_request(struct pwm_device *pwm, const char *label) |
109 | { | |
110 | int err; | |
111 | ||
112 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
113 | return -EBUSY; | |
114 | ||
115 | if (!try_module_get(pwm->chip->ops->owner)) | |
116 | return -ENODEV; | |
117 | ||
118 | if (pwm->chip->ops->request) { | |
119 | err = pwm->chip->ops->request(pwm->chip, pwm); | |
120 | if (err) { | |
121 | module_put(pwm->chip->ops->owner); | |
122 | return err; | |
123 | } | |
124 | } | |
125 | ||
126 | set_bit(PWMF_REQUESTED, &pwm->flags); | |
127 | pwm->label = label; | |
128 | ||
129 | return 0; | |
130 | } | |
131 | ||
e50d3523 SK |
132 | static struct pwm_device * |
133 | of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) | |
7299ab70 TR |
134 | { |
135 | struct pwm_device *pwm; | |
136 | ||
137 | if (pc->of_pwm_n_cells < 2) | |
138 | return ERR_PTR(-EINVAL); | |
139 | ||
140 | if (args->args[0] >= pc->npwm) | |
141 | return ERR_PTR(-EINVAL); | |
142 | ||
143 | pwm = pwm_request_from_chip(pc, args->args[0], NULL); | |
144 | if (IS_ERR(pwm)) | |
145 | return pwm; | |
146 | ||
147 | pwm_set_period(pwm, args->args[1]); | |
148 | ||
149 | return pwm; | |
150 | } | |
151 | ||
dfeb86ec | 152 | static void of_pwmchip_add(struct pwm_chip *chip) |
7299ab70 TR |
153 | { |
154 | if (!chip->dev || !chip->dev->of_node) | |
155 | return; | |
156 | ||
157 | if (!chip->of_xlate) { | |
158 | chip->of_xlate = of_pwm_simple_xlate; | |
159 | chip->of_pwm_n_cells = 2; | |
160 | } | |
161 | ||
162 | of_node_get(chip->dev->of_node); | |
163 | } | |
164 | ||
dfeb86ec | 165 | static void of_pwmchip_remove(struct pwm_chip *chip) |
7299ab70 TR |
166 | { |
167 | if (chip->dev && chip->dev->of_node) | |
168 | of_node_put(chip->dev->of_node); | |
169 | } | |
170 | ||
f051c466 TR |
171 | /** |
172 | * pwm_set_chip_data() - set private chip data for a PWM | |
173 | * @pwm: PWM device | |
174 | * @data: pointer to chip-specific data | |
175 | */ | |
176 | int pwm_set_chip_data(struct pwm_device *pwm, void *data) | |
177 | { | |
178 | if (!pwm) | |
179 | return -EINVAL; | |
180 | ||
181 | pwm->chip_data = data; | |
182 | ||
183 | return 0; | |
184 | } | |
185 | ||
186 | /** | |
187 | * pwm_get_chip_data() - get private chip data for a PWM | |
188 | * @pwm: PWM device | |
189 | */ | |
190 | void *pwm_get_chip_data(struct pwm_device *pwm) | |
191 | { | |
192 | return pwm ? pwm->chip_data : NULL; | |
0c2498f1 SH |
193 | } |
194 | ||
195 | /** | |
196 | * pwmchip_add() - register a new PWM chip | |
197 | * @chip: the PWM chip to add | |
f051c466 TR |
198 | * |
199 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base | |
200 | * will be used. | |
0c2498f1 SH |
201 | */ |
202 | int pwmchip_add(struct pwm_chip *chip) | |
203 | { | |
204 | struct pwm_device *pwm; | |
f051c466 TR |
205 | unsigned int i; |
206 | int ret; | |
0c2498f1 | 207 | |
f051c466 TR |
208 | if (!chip || !chip->dev || !chip->ops || !chip->ops->config || |
209 | !chip->ops->enable || !chip->ops->disable) | |
210 | return -EINVAL; | |
0c2498f1 SH |
211 | |
212 | mutex_lock(&pwm_lock); | |
213 | ||
f051c466 TR |
214 | ret = alloc_pwms(chip->base, chip->npwm); |
215 | if (ret < 0) | |
216 | goto out; | |
217 | ||
218 | chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL); | |
219 | if (!chip->pwms) { | |
220 | ret = -ENOMEM; | |
0c2498f1 SH |
221 | goto out; |
222 | } | |
223 | ||
f051c466 TR |
224 | chip->base = ret; |
225 | ||
226 | for (i = 0; i < chip->npwm; i++) { | |
227 | pwm = &chip->pwms[i]; | |
228 | ||
229 | pwm->chip = chip; | |
230 | pwm->pwm = chip->base + i; | |
231 | pwm->hwpwm = i; | |
0c2498f1 | 232 | |
f051c466 TR |
233 | radix_tree_insert(&pwm_tree, pwm->pwm, pwm); |
234 | } | |
235 | ||
236 | bitmap_set(allocated_pwms, chip->base, chip->npwm); | |
237 | ||
238 | INIT_LIST_HEAD(&chip->list); | |
239 | list_add(&chip->list, &pwm_chips); | |
0c2498f1 | 240 | |
f051c466 TR |
241 | ret = 0; |
242 | ||
7299ab70 TR |
243 | if (IS_ENABLED(CONFIG_OF)) |
244 | of_pwmchip_add(chip); | |
245 | ||
f051c466 TR |
246 | out: |
247 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
248 | return ret; |
249 | } | |
250 | EXPORT_SYMBOL_GPL(pwmchip_add); | |
251 | ||
252 | /** | |
253 | * pwmchip_remove() - remove a PWM chip | |
254 | * @chip: the PWM chip to remove | |
255 | * | |
256 | * Removes a PWM chip. This function may return busy if the PWM chip provides | |
257 | * a PWM device that is still requested. | |
258 | */ | |
259 | int pwmchip_remove(struct pwm_chip *chip) | |
260 | { | |
f051c466 | 261 | unsigned int i; |
0c2498f1 SH |
262 | int ret = 0; |
263 | ||
264 | mutex_lock(&pwm_lock); | |
265 | ||
f051c466 TR |
266 | for (i = 0; i < chip->npwm; i++) { |
267 | struct pwm_device *pwm = &chip->pwms[i]; | |
0c2498f1 | 268 | |
f051c466 TR |
269 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) { |
270 | ret = -EBUSY; | |
271 | goto out; | |
272 | } | |
0c2498f1 SH |
273 | } |
274 | ||
f051c466 | 275 | list_del_init(&chip->list); |
7299ab70 TR |
276 | |
277 | if (IS_ENABLED(CONFIG_OF)) | |
278 | of_pwmchip_remove(chip); | |
279 | ||
f051c466 | 280 | free_pwms(chip); |
0c2498f1 | 281 | |
0c2498f1 SH |
282 | out: |
283 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
284 | return ret; |
285 | } | |
286 | EXPORT_SYMBOL_GPL(pwmchip_remove); | |
287 | ||
288 | /** | |
289 | * pwm_request() - request a PWM device | |
290 | * @pwm_id: global PWM device index | |
291 | * @label: PWM device label | |
8138d2dd TR |
292 | * |
293 | * This function is deprecated, use pwm_get() instead. | |
0c2498f1 | 294 | */ |
f051c466 | 295 | struct pwm_device *pwm_request(int pwm, const char *label) |
0c2498f1 | 296 | { |
f051c466 TR |
297 | struct pwm_device *dev; |
298 | int err; | |
299 | ||
300 | if (pwm < 0 || pwm >= MAX_PWMS) | |
301 | return ERR_PTR(-EINVAL); | |
0c2498f1 SH |
302 | |
303 | mutex_lock(&pwm_lock); | |
304 | ||
f051c466 TR |
305 | dev = pwm_to_device(pwm); |
306 | if (!dev) { | |
307 | dev = ERR_PTR(-EPROBE_DEFER); | |
0c2498f1 SH |
308 | goto out; |
309 | } | |
310 | ||
f051c466 TR |
311 | err = pwm_device_request(dev, label); |
312 | if (err < 0) | |
313 | dev = ERR_PTR(err); | |
0c2498f1 | 314 | |
f051c466 TR |
315 | out: |
316 | mutex_unlock(&pwm_lock); | |
0c2498f1 | 317 | |
f051c466 TR |
318 | return dev; |
319 | } | |
320 | EXPORT_SYMBOL_GPL(pwm_request); | |
0c2498f1 | 321 | |
f051c466 TR |
322 | /** |
323 | * pwm_request_from_chip() - request a PWM device relative to a PWM chip | |
324 | * @chip: PWM chip | |
325 | * @index: per-chip index of the PWM to request | |
326 | * @label: a literal description string of this PWM | |
327 | * | |
328 | * Returns the PWM at the given index of the given PWM chip. A negative error | |
329 | * code is returned if the index is not valid for the specified PWM chip or | |
330 | * if the PWM device cannot be requested. | |
331 | */ | |
332 | struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, | |
333 | unsigned int index, | |
334 | const char *label) | |
335 | { | |
336 | struct pwm_device *pwm; | |
337 | int err; | |
0c2498f1 | 338 | |
f051c466 TR |
339 | if (!chip || index >= chip->npwm) |
340 | return ERR_PTR(-EINVAL); | |
0c2498f1 | 341 | |
f051c466 TR |
342 | mutex_lock(&pwm_lock); |
343 | pwm = &chip->pwms[index]; | |
0c2498f1 | 344 | |
f051c466 TR |
345 | err = pwm_device_request(pwm, label); |
346 | if (err < 0) | |
347 | pwm = ERR_PTR(err); | |
348 | ||
349 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
350 | return pwm; |
351 | } | |
f051c466 | 352 | EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
0c2498f1 SH |
353 | |
354 | /** | |
355 | * pwm_free() - free a PWM device | |
356 | * @pwm: PWM device | |
8138d2dd TR |
357 | * |
358 | * This function is deprecated, use pwm_put() instead. | |
0c2498f1 SH |
359 | */ |
360 | void pwm_free(struct pwm_device *pwm) | |
361 | { | |
8138d2dd | 362 | pwm_put(pwm); |
0c2498f1 SH |
363 | } |
364 | EXPORT_SYMBOL_GPL(pwm_free); | |
365 | ||
366 | /** | |
367 | * pwm_config() - change a PWM device configuration | |
368 | * @pwm: PWM device | |
369 | * @duty_ns: "on" time (in nanoseconds) | |
370 | * @period_ns: duration (in nanoseconds) of one cycle | |
371 | */ | |
372 | int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) | |
373 | { | |
f051c466 TR |
374 | if (!pwm || period_ns == 0 || duty_ns > period_ns) |
375 | return -EINVAL; | |
376 | ||
377 | return pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); | |
0c2498f1 SH |
378 | } |
379 | EXPORT_SYMBOL_GPL(pwm_config); | |
380 | ||
0aa0869c PA |
381 | /** |
382 | * pwm_set_polarity() - configure the polarity of a PWM signal | |
383 | * @pwm: PWM device | |
384 | * @polarity: new polarity of the PWM signal | |
385 | * | |
386 | * Note that the polarity cannot be configured while the PWM device is enabled | |
387 | */ | |
388 | int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) | |
389 | { | |
390 | if (!pwm || !pwm->chip->ops) | |
391 | return -EINVAL; | |
392 | ||
393 | if (!pwm->chip->ops->set_polarity) | |
394 | return -ENOSYS; | |
395 | ||
396 | if (test_bit(PWMF_ENABLED, &pwm->flags)) | |
397 | return -EBUSY; | |
398 | ||
399 | return pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity); | |
400 | } | |
401 | EXPORT_SYMBOL_GPL(pwm_set_polarity); | |
402 | ||
0c2498f1 SH |
403 | /** |
404 | * pwm_enable() - start a PWM output toggling | |
405 | * @pwm: PWM device | |
406 | */ | |
407 | int pwm_enable(struct pwm_device *pwm) | |
408 | { | |
f051c466 TR |
409 | if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags)) |
410 | return pwm->chip->ops->enable(pwm->chip, pwm); | |
0c2498f1 | 411 | |
f051c466 | 412 | return pwm ? 0 : -EINVAL; |
0c2498f1 SH |
413 | } |
414 | EXPORT_SYMBOL_GPL(pwm_enable); | |
415 | ||
416 | /** | |
417 | * pwm_disable() - stop a PWM output toggling | |
418 | * @pwm: PWM device | |
419 | */ | |
420 | void pwm_disable(struct pwm_device *pwm) | |
421 | { | |
f051c466 TR |
422 | if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags)) |
423 | pwm->chip->ops->disable(pwm->chip, pwm); | |
0c2498f1 SH |
424 | } |
425 | EXPORT_SYMBOL_GPL(pwm_disable); | |
62099abf | 426 | |
7299ab70 TR |
427 | static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) |
428 | { | |
429 | struct pwm_chip *chip; | |
430 | ||
431 | mutex_lock(&pwm_lock); | |
432 | ||
433 | list_for_each_entry(chip, &pwm_chips, list) | |
434 | if (chip->dev && chip->dev->of_node == np) { | |
435 | mutex_unlock(&pwm_lock); | |
436 | return chip; | |
437 | } | |
438 | ||
439 | mutex_unlock(&pwm_lock); | |
440 | ||
441 | return ERR_PTR(-EPROBE_DEFER); | |
442 | } | |
443 | ||
444 | /** | |
445 | * of_pwm_request() - request a PWM via the PWM framework | |
446 | * @np: device node to get the PWM from | |
447 | * @con_id: consumer name | |
448 | * | |
449 | * Returns the PWM device parsed from the phandle and index specified in the | |
450 | * "pwms" property of a device tree node or a negative error-code on failure. | |
451 | * Values parsed from the device tree are stored in the returned PWM device | |
452 | * object. | |
453 | * | |
454 | * If con_id is NULL, the first PWM device listed in the "pwms" property will | |
455 | * be requested. Otherwise the "pwm-names" property is used to do a reverse | |
456 | * lookup of the PWM index. This also means that the "pwm-names" property | |
457 | * becomes mandatory for devices that look up the PWM device via the con_id | |
458 | * parameter. | |
459 | */ | |
460 | static struct pwm_device *of_pwm_request(struct device_node *np, | |
461 | const char *con_id) | |
462 | { | |
463 | struct pwm_device *pwm = NULL; | |
464 | struct of_phandle_args args; | |
465 | struct pwm_chip *pc; | |
466 | int index = 0; | |
467 | int err; | |
468 | ||
469 | if (con_id) { | |
470 | index = of_property_match_string(np, "pwm-names", con_id); | |
471 | if (index < 0) | |
472 | return ERR_PTR(index); | |
473 | } | |
474 | ||
475 | err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, | |
476 | &args); | |
477 | if (err) { | |
478 | pr_debug("%s(): can't parse \"pwms\" property\n", __func__); | |
479 | return ERR_PTR(err); | |
480 | } | |
481 | ||
482 | pc = of_node_to_pwmchip(args.np); | |
483 | if (IS_ERR(pc)) { | |
484 | pr_debug("%s(): PWM chip not found\n", __func__); | |
485 | pwm = ERR_CAST(pc); | |
486 | goto put; | |
487 | } | |
488 | ||
489 | if (args.args_count != pc->of_pwm_n_cells) { | |
490 | pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name, | |
491 | args.np->full_name); | |
492 | pwm = ERR_PTR(-EINVAL); | |
493 | goto put; | |
494 | } | |
495 | ||
496 | pwm = pc->of_xlate(pc, &args); | |
497 | if (IS_ERR(pwm)) | |
498 | goto put; | |
499 | ||
500 | /* | |
501 | * If a consumer name was not given, try to look it up from the | |
502 | * "pwm-names" property if it exists. Otherwise use the name of | |
503 | * the user device node. | |
504 | */ | |
505 | if (!con_id) { | |
506 | err = of_property_read_string_index(np, "pwm-names", index, | |
507 | &con_id); | |
508 | if (err < 0) | |
509 | con_id = np->name; | |
510 | } | |
511 | ||
512 | pwm->label = con_id; | |
513 | ||
514 | put: | |
515 | of_node_put(args.np); | |
516 | ||
517 | return pwm; | |
518 | } | |
519 | ||
8138d2dd TR |
520 | /** |
521 | * pwm_add_table() - register PWM device consumers | |
522 | * @table: array of consumers to register | |
523 | * @num: number of consumers in table | |
524 | */ | |
525 | void __init pwm_add_table(struct pwm_lookup *table, size_t num) | |
526 | { | |
527 | mutex_lock(&pwm_lookup_lock); | |
528 | ||
529 | while (num--) { | |
530 | list_add_tail(&table->list, &pwm_lookup_list); | |
531 | table++; | |
532 | } | |
533 | ||
534 | mutex_unlock(&pwm_lookup_lock); | |
535 | } | |
536 | ||
537 | /** | |
538 | * pwm_get() - look up and request a PWM device | |
539 | * @dev: device for PWM consumer | |
540 | * @con_id: consumer name | |
541 | * | |
7299ab70 TR |
542 | * Lookup is first attempted using DT. If the device was not instantiated from |
543 | * a device tree, a PWM chip and a relative index is looked up via a table | |
544 | * supplied by board setup code (see pwm_add_table()). | |
8138d2dd TR |
545 | * |
546 | * Once a PWM chip has been found the specified PWM device will be requested | |
547 | * and is ready to be used. | |
548 | */ | |
549 | struct pwm_device *pwm_get(struct device *dev, const char *con_id) | |
550 | { | |
551 | struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER); | |
e50d3523 | 552 | const char *dev_id = dev ? dev_name(dev) : NULL; |
8138d2dd | 553 | struct pwm_chip *chip = NULL; |
d295b129 | 554 | unsigned int index = 0; |
8138d2dd TR |
555 | unsigned int best = 0; |
556 | struct pwm_lookup *p; | |
8138d2dd TR |
557 | unsigned int match; |
558 | ||
7299ab70 TR |
559 | /* look up via DT first */ |
560 | if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) | |
561 | return of_pwm_request(dev->of_node, con_id); | |
562 | ||
8138d2dd TR |
563 | /* |
564 | * We look up the provider in the static table typically provided by | |
565 | * board setup code. We first try to lookup the consumer device by | |
566 | * name. If the consumer device was passed in as NULL or if no match | |
567 | * was found, we try to find the consumer by directly looking it up | |
568 | * by name. | |
569 | * | |
570 | * If a match is found, the provider PWM chip is looked up by name | |
571 | * and a PWM device is requested using the PWM device per-chip index. | |
572 | * | |
573 | * The lookup algorithm was shamelessly taken from the clock | |
574 | * framework: | |
575 | * | |
576 | * We do slightly fuzzy matching here: | |
577 | * An entry with a NULL ID is assumed to be a wildcard. | |
578 | * If an entry has a device ID, it must match | |
579 | * If an entry has a connection ID, it must match | |
580 | * Then we take the most specific entry - with the following order | |
581 | * of precedence: dev+con > dev only > con only. | |
582 | */ | |
583 | mutex_lock(&pwm_lookup_lock); | |
584 | ||
585 | list_for_each_entry(p, &pwm_lookup_list, list) { | |
586 | match = 0; | |
587 | ||
588 | if (p->dev_id) { | |
589 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
590 | continue; | |
591 | ||
592 | match += 2; | |
593 | } | |
594 | ||
595 | if (p->con_id) { | |
596 | if (!con_id || strcmp(p->con_id, con_id)) | |
597 | continue; | |
598 | ||
599 | match += 1; | |
600 | } | |
601 | ||
602 | if (match > best) { | |
603 | chip = pwmchip_find_by_name(p->provider); | |
604 | index = p->index; | |
605 | ||
606 | if (match != 3) | |
607 | best = match; | |
608 | else | |
609 | break; | |
610 | } | |
611 | } | |
612 | ||
613 | if (chip) | |
614 | pwm = pwm_request_from_chip(chip, index, con_id ?: dev_id); | |
615 | ||
616 | mutex_unlock(&pwm_lookup_lock); | |
617 | ||
618 | return pwm; | |
619 | } | |
620 | EXPORT_SYMBOL_GPL(pwm_get); | |
621 | ||
622 | /** | |
623 | * pwm_put() - release a PWM device | |
624 | * @pwm: PWM device | |
625 | */ | |
626 | void pwm_put(struct pwm_device *pwm) | |
627 | { | |
628 | if (!pwm) | |
629 | return; | |
630 | ||
631 | mutex_lock(&pwm_lock); | |
632 | ||
633 | if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { | |
e50d3523 | 634 | pr_warn("PWM device already freed\n"); |
8138d2dd TR |
635 | goto out; |
636 | } | |
637 | ||
638 | if (pwm->chip->ops->free) | |
639 | pwm->chip->ops->free(pwm->chip, pwm); | |
640 | ||
641 | pwm->label = NULL; | |
642 | ||
643 | module_put(pwm->chip->ops->owner); | |
644 | out: | |
645 | mutex_unlock(&pwm_lock); | |
646 | } | |
647 | EXPORT_SYMBOL_GPL(pwm_put); | |
648 | ||
6354316d AC |
649 | static void devm_pwm_release(struct device *dev, void *res) |
650 | { | |
651 | pwm_put(*(struct pwm_device **)res); | |
652 | } | |
653 | ||
654 | /** | |
655 | * devm_pwm_get() - resource managed pwm_get() | |
656 | * @dev: device for PWM consumer | |
657 | * @con_id: consumer name | |
658 | * | |
659 | * This function performs like pwm_get() but the acquired PWM device will | |
660 | * automatically be released on driver detach. | |
661 | */ | |
662 | struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id) | |
663 | { | |
664 | struct pwm_device **ptr, *pwm; | |
665 | ||
666 | ptr = devres_alloc(devm_pwm_release, sizeof(**ptr), GFP_KERNEL); | |
667 | if (!ptr) | |
668 | return ERR_PTR(-ENOMEM); | |
669 | ||
670 | pwm = pwm_get(dev, con_id); | |
671 | if (!IS_ERR(pwm)) { | |
672 | *ptr = pwm; | |
673 | devres_add(dev, ptr); | |
674 | } else { | |
675 | devres_free(ptr); | |
676 | } | |
677 | ||
678 | return pwm; | |
679 | } | |
680 | EXPORT_SYMBOL_GPL(devm_pwm_get); | |
681 | ||
682 | static int devm_pwm_match(struct device *dev, void *res, void *data) | |
683 | { | |
684 | struct pwm_device **p = res; | |
685 | ||
686 | if (WARN_ON(!p || !*p)) | |
687 | return 0; | |
688 | ||
689 | return *p == data; | |
690 | } | |
691 | ||
692 | /** | |
693 | * devm_pwm_put() - resource managed pwm_put() | |
694 | * @dev: device for PWM consumer | |
695 | * @pwm: PWM device | |
696 | * | |
697 | * Release a PWM previously allocated using devm_pwm_get(). Calling this | |
698 | * function is usually not needed because devm-allocated resources are | |
699 | * automatically released on driver detach. | |
700 | */ | |
701 | void devm_pwm_put(struct device *dev, struct pwm_device *pwm) | |
702 | { | |
703 | WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm)); | |
704 | } | |
705 | EXPORT_SYMBOL_GPL(devm_pwm_put); | |
706 | ||
62099abf TR |
707 | #ifdef CONFIG_DEBUG_FS |
708 | static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) | |
709 | { | |
710 | unsigned int i; | |
711 | ||
712 | for (i = 0; i < chip->npwm; i++) { | |
713 | struct pwm_device *pwm = &chip->pwms[i]; | |
714 | ||
715 | seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); | |
716 | ||
717 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
718 | seq_printf(s, " requested"); | |
719 | ||
720 | if (test_bit(PWMF_ENABLED, &pwm->flags)) | |
721 | seq_printf(s, " enabled"); | |
722 | ||
723 | seq_printf(s, "\n"); | |
724 | } | |
725 | } | |
726 | ||
727 | static void *pwm_seq_start(struct seq_file *s, loff_t *pos) | |
728 | { | |
729 | mutex_lock(&pwm_lock); | |
730 | s->private = ""; | |
731 | ||
732 | return seq_list_start(&pwm_chips, *pos); | |
733 | } | |
734 | ||
735 | static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
736 | { | |
737 | s->private = "\n"; | |
738 | ||
739 | return seq_list_next(v, &pwm_chips, pos); | |
740 | } | |
741 | ||
742 | static void pwm_seq_stop(struct seq_file *s, void *v) | |
743 | { | |
744 | mutex_unlock(&pwm_lock); | |
745 | } | |
746 | ||
747 | static int pwm_seq_show(struct seq_file *s, void *v) | |
748 | { | |
749 | struct pwm_chip *chip = list_entry(v, struct pwm_chip, list); | |
750 | ||
751 | seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private, | |
752 | chip->dev->bus ? chip->dev->bus->name : "no-bus", | |
753 | dev_name(chip->dev), chip->npwm, | |
754 | (chip->npwm != 1) ? "s" : ""); | |
755 | ||
756 | if (chip->ops->dbg_show) | |
757 | chip->ops->dbg_show(chip, s); | |
758 | else | |
759 | pwm_dbg_show(chip, s); | |
760 | ||
761 | return 0; | |
762 | } | |
763 | ||
764 | static const struct seq_operations pwm_seq_ops = { | |
765 | .start = pwm_seq_start, | |
766 | .next = pwm_seq_next, | |
767 | .stop = pwm_seq_stop, | |
768 | .show = pwm_seq_show, | |
769 | }; | |
770 | ||
771 | static int pwm_seq_open(struct inode *inode, struct file *file) | |
772 | { | |
773 | return seq_open(file, &pwm_seq_ops); | |
774 | } | |
775 | ||
776 | static const struct file_operations pwm_debugfs_ops = { | |
777 | .owner = THIS_MODULE, | |
778 | .open = pwm_seq_open, | |
779 | .read = seq_read, | |
780 | .llseek = seq_lseek, | |
781 | .release = seq_release, | |
782 | }; | |
783 | ||
784 | static int __init pwm_debugfs_init(void) | |
785 | { | |
786 | debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL, | |
787 | &pwm_debugfs_ops); | |
788 | ||
789 | return 0; | |
790 | } | |
791 | ||
792 | subsys_initcall(pwm_debugfs_init); | |
793 | #endif /* CONFIG_DEBUG_FS */ |