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 | } | |
928c4477 | 214 | EXPORT_SYMBOL_GPL(pwm_set_chip_data); |
f051c466 TR |
215 | |
216 | /** | |
217 | * pwm_get_chip_data() - get private chip data for a PWM | |
218 | * @pwm: PWM device | |
219 | */ | |
220 | void *pwm_get_chip_data(struct pwm_device *pwm) | |
221 | { | |
222 | return pwm ? pwm->chip_data : NULL; | |
0c2498f1 | 223 | } |
928c4477 | 224 | EXPORT_SYMBOL_GPL(pwm_get_chip_data); |
0c2498f1 SH |
225 | |
226 | /** | |
227 | * pwmchip_add() - register a new PWM chip | |
228 | * @chip: the PWM chip to add | |
f051c466 TR |
229 | * |
230 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base | |
231 | * will be used. | |
0c2498f1 SH |
232 | */ |
233 | int pwmchip_add(struct pwm_chip *chip) | |
234 | { | |
235 | struct pwm_device *pwm; | |
f051c466 TR |
236 | unsigned int i; |
237 | int ret; | |
0c2498f1 | 238 | |
f051c466 TR |
239 | if (!chip || !chip->dev || !chip->ops || !chip->ops->config || |
240 | !chip->ops->enable || !chip->ops->disable) | |
241 | return -EINVAL; | |
0c2498f1 SH |
242 | |
243 | mutex_lock(&pwm_lock); | |
244 | ||
f051c466 TR |
245 | ret = alloc_pwms(chip->base, chip->npwm); |
246 | if (ret < 0) | |
247 | goto out; | |
248 | ||
249 | chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL); | |
250 | if (!chip->pwms) { | |
251 | ret = -ENOMEM; | |
0c2498f1 SH |
252 | goto out; |
253 | } | |
254 | ||
f051c466 TR |
255 | chip->base = ret; |
256 | ||
257 | for (i = 0; i < chip->npwm; i++) { | |
258 | pwm = &chip->pwms[i]; | |
259 | ||
260 | pwm->chip = chip; | |
261 | pwm->pwm = chip->base + i; | |
262 | pwm->hwpwm = i; | |
0c2498f1 | 263 | |
f051c466 TR |
264 | radix_tree_insert(&pwm_tree, pwm->pwm, pwm); |
265 | } | |
266 | ||
267 | bitmap_set(allocated_pwms, chip->base, chip->npwm); | |
268 | ||
269 | INIT_LIST_HEAD(&chip->list); | |
270 | list_add(&chip->list, &pwm_chips); | |
0c2498f1 | 271 | |
f051c466 TR |
272 | ret = 0; |
273 | ||
7299ab70 TR |
274 | if (IS_ENABLED(CONFIG_OF)) |
275 | of_pwmchip_add(chip); | |
276 | ||
f051c466 TR |
277 | out: |
278 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
279 | return ret; |
280 | } | |
281 | EXPORT_SYMBOL_GPL(pwmchip_add); | |
282 | ||
283 | /** | |
284 | * pwmchip_remove() - remove a PWM chip | |
285 | * @chip: the PWM chip to remove | |
286 | * | |
287 | * Removes a PWM chip. This function may return busy if the PWM chip provides | |
288 | * a PWM device that is still requested. | |
289 | */ | |
290 | int pwmchip_remove(struct pwm_chip *chip) | |
291 | { | |
f051c466 | 292 | unsigned int i; |
0c2498f1 SH |
293 | int ret = 0; |
294 | ||
295 | mutex_lock(&pwm_lock); | |
296 | ||
f051c466 TR |
297 | for (i = 0; i < chip->npwm; i++) { |
298 | struct pwm_device *pwm = &chip->pwms[i]; | |
0c2498f1 | 299 | |
f051c466 TR |
300 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) { |
301 | ret = -EBUSY; | |
302 | goto out; | |
303 | } | |
0c2498f1 SH |
304 | } |
305 | ||
f051c466 | 306 | list_del_init(&chip->list); |
7299ab70 TR |
307 | |
308 | if (IS_ENABLED(CONFIG_OF)) | |
309 | of_pwmchip_remove(chip); | |
310 | ||
f051c466 | 311 | free_pwms(chip); |
0c2498f1 | 312 | |
0c2498f1 SH |
313 | out: |
314 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
315 | return ret; |
316 | } | |
317 | EXPORT_SYMBOL_GPL(pwmchip_remove); | |
318 | ||
319 | /** | |
320 | * pwm_request() - request a PWM device | |
321 | * @pwm_id: global PWM device index | |
322 | * @label: PWM device label | |
8138d2dd TR |
323 | * |
324 | * This function is deprecated, use pwm_get() instead. | |
0c2498f1 | 325 | */ |
f051c466 | 326 | struct pwm_device *pwm_request(int pwm, const char *label) |
0c2498f1 | 327 | { |
f051c466 TR |
328 | struct pwm_device *dev; |
329 | int err; | |
330 | ||
331 | if (pwm < 0 || pwm >= MAX_PWMS) | |
332 | return ERR_PTR(-EINVAL); | |
0c2498f1 SH |
333 | |
334 | mutex_lock(&pwm_lock); | |
335 | ||
f051c466 TR |
336 | dev = pwm_to_device(pwm); |
337 | if (!dev) { | |
338 | dev = ERR_PTR(-EPROBE_DEFER); | |
0c2498f1 SH |
339 | goto out; |
340 | } | |
341 | ||
f051c466 TR |
342 | err = pwm_device_request(dev, label); |
343 | if (err < 0) | |
344 | dev = ERR_PTR(err); | |
0c2498f1 | 345 | |
f051c466 TR |
346 | out: |
347 | mutex_unlock(&pwm_lock); | |
0c2498f1 | 348 | |
f051c466 TR |
349 | return dev; |
350 | } | |
351 | EXPORT_SYMBOL_GPL(pwm_request); | |
0c2498f1 | 352 | |
f051c466 TR |
353 | /** |
354 | * pwm_request_from_chip() - request a PWM device relative to a PWM chip | |
355 | * @chip: PWM chip | |
356 | * @index: per-chip index of the PWM to request | |
357 | * @label: a literal description string of this PWM | |
358 | * | |
359 | * Returns the PWM at the given index of the given PWM chip. A negative error | |
360 | * code is returned if the index is not valid for the specified PWM chip or | |
361 | * if the PWM device cannot be requested. | |
362 | */ | |
363 | struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, | |
364 | unsigned int index, | |
365 | const char *label) | |
366 | { | |
367 | struct pwm_device *pwm; | |
368 | int err; | |
0c2498f1 | 369 | |
f051c466 TR |
370 | if (!chip || index >= chip->npwm) |
371 | return ERR_PTR(-EINVAL); | |
0c2498f1 | 372 | |
f051c466 TR |
373 | mutex_lock(&pwm_lock); |
374 | pwm = &chip->pwms[index]; | |
0c2498f1 | 375 | |
f051c466 TR |
376 | err = pwm_device_request(pwm, label); |
377 | if (err < 0) | |
378 | pwm = ERR_PTR(err); | |
379 | ||
380 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
381 | return pwm; |
382 | } | |
f051c466 | 383 | EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
0c2498f1 SH |
384 | |
385 | /** | |
386 | * pwm_free() - free a PWM device | |
387 | * @pwm: PWM device | |
8138d2dd TR |
388 | * |
389 | * This function is deprecated, use pwm_put() instead. | |
0c2498f1 SH |
390 | */ |
391 | void pwm_free(struct pwm_device *pwm) | |
392 | { | |
8138d2dd | 393 | pwm_put(pwm); |
0c2498f1 SH |
394 | } |
395 | EXPORT_SYMBOL_GPL(pwm_free); | |
396 | ||
397 | /** | |
398 | * pwm_config() - change a PWM device configuration | |
399 | * @pwm: PWM device | |
400 | * @duty_ns: "on" time (in nanoseconds) | |
401 | * @period_ns: duration (in nanoseconds) of one cycle | |
402 | */ | |
403 | int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) | |
404 | { | |
c2d476a9 | 405 | if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns) |
f051c466 TR |
406 | return -EINVAL; |
407 | ||
408 | return pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); | |
0c2498f1 SH |
409 | } |
410 | EXPORT_SYMBOL_GPL(pwm_config); | |
411 | ||
0aa0869c PA |
412 | /** |
413 | * pwm_set_polarity() - configure the polarity of a PWM signal | |
414 | * @pwm: PWM device | |
415 | * @polarity: new polarity of the PWM signal | |
416 | * | |
417 | * Note that the polarity cannot be configured while the PWM device is enabled | |
418 | */ | |
419 | int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) | |
420 | { | |
421 | if (!pwm || !pwm->chip->ops) | |
422 | return -EINVAL; | |
423 | ||
424 | if (!pwm->chip->ops->set_polarity) | |
425 | return -ENOSYS; | |
426 | ||
427 | if (test_bit(PWMF_ENABLED, &pwm->flags)) | |
428 | return -EBUSY; | |
429 | ||
430 | return pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity); | |
431 | } | |
432 | EXPORT_SYMBOL_GPL(pwm_set_polarity); | |
433 | ||
0c2498f1 SH |
434 | /** |
435 | * pwm_enable() - start a PWM output toggling | |
436 | * @pwm: PWM device | |
437 | */ | |
438 | int pwm_enable(struct pwm_device *pwm) | |
439 | { | |
f051c466 TR |
440 | if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags)) |
441 | return pwm->chip->ops->enable(pwm->chip, pwm); | |
0c2498f1 | 442 | |
f051c466 | 443 | return pwm ? 0 : -EINVAL; |
0c2498f1 SH |
444 | } |
445 | EXPORT_SYMBOL_GPL(pwm_enable); | |
446 | ||
447 | /** | |
448 | * pwm_disable() - stop a PWM output toggling | |
449 | * @pwm: PWM device | |
450 | */ | |
451 | void pwm_disable(struct pwm_device *pwm) | |
452 | { | |
f051c466 TR |
453 | if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags)) |
454 | pwm->chip->ops->disable(pwm->chip, pwm); | |
0c2498f1 SH |
455 | } |
456 | EXPORT_SYMBOL_GPL(pwm_disable); | |
62099abf | 457 | |
7299ab70 TR |
458 | static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) |
459 | { | |
460 | struct pwm_chip *chip; | |
461 | ||
462 | mutex_lock(&pwm_lock); | |
463 | ||
464 | list_for_each_entry(chip, &pwm_chips, list) | |
465 | if (chip->dev && chip->dev->of_node == np) { | |
466 | mutex_unlock(&pwm_lock); | |
467 | return chip; | |
468 | } | |
469 | ||
470 | mutex_unlock(&pwm_lock); | |
471 | ||
472 | return ERR_PTR(-EPROBE_DEFER); | |
473 | } | |
474 | ||
475 | /** | |
8eb96127 | 476 | * of_pwm_get() - request a PWM via the PWM framework |
7299ab70 TR |
477 | * @np: device node to get the PWM from |
478 | * @con_id: consumer name | |
479 | * | |
480 | * Returns the PWM device parsed from the phandle and index specified in the | |
481 | * "pwms" property of a device tree node or a negative error-code on failure. | |
482 | * Values parsed from the device tree are stored in the returned PWM device | |
483 | * object. | |
484 | * | |
485 | * If con_id is NULL, the first PWM device listed in the "pwms" property will | |
486 | * be requested. Otherwise the "pwm-names" property is used to do a reverse | |
487 | * lookup of the PWM index. This also means that the "pwm-names" property | |
488 | * becomes mandatory for devices that look up the PWM device via the con_id | |
489 | * parameter. | |
490 | */ | |
8eb96127 | 491 | struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) |
7299ab70 TR |
492 | { |
493 | struct pwm_device *pwm = NULL; | |
494 | struct of_phandle_args args; | |
495 | struct pwm_chip *pc; | |
496 | int index = 0; | |
497 | int err; | |
498 | ||
499 | if (con_id) { | |
500 | index = of_property_match_string(np, "pwm-names", con_id); | |
501 | if (index < 0) | |
502 | return ERR_PTR(index); | |
503 | } | |
504 | ||
505 | err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, | |
506 | &args); | |
507 | if (err) { | |
508 | pr_debug("%s(): can't parse \"pwms\" property\n", __func__); | |
509 | return ERR_PTR(err); | |
510 | } | |
511 | ||
512 | pc = of_node_to_pwmchip(args.np); | |
513 | if (IS_ERR(pc)) { | |
514 | pr_debug("%s(): PWM chip not found\n", __func__); | |
515 | pwm = ERR_CAST(pc); | |
516 | goto put; | |
517 | } | |
518 | ||
519 | if (args.args_count != pc->of_pwm_n_cells) { | |
520 | pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name, | |
521 | args.np->full_name); | |
522 | pwm = ERR_PTR(-EINVAL); | |
523 | goto put; | |
524 | } | |
525 | ||
526 | pwm = pc->of_xlate(pc, &args); | |
527 | if (IS_ERR(pwm)) | |
528 | goto put; | |
529 | ||
530 | /* | |
531 | * If a consumer name was not given, try to look it up from the | |
532 | * "pwm-names" property if it exists. Otherwise use the name of | |
533 | * the user device node. | |
534 | */ | |
535 | if (!con_id) { | |
536 | err = of_property_read_string_index(np, "pwm-names", index, | |
537 | &con_id); | |
538 | if (err < 0) | |
539 | con_id = np->name; | |
540 | } | |
541 | ||
542 | pwm->label = con_id; | |
543 | ||
544 | put: | |
545 | of_node_put(args.np); | |
546 | ||
547 | return pwm; | |
548 | } | |
8eb96127 | 549 | EXPORT_SYMBOL_GPL(of_pwm_get); |
7299ab70 | 550 | |
8138d2dd TR |
551 | /** |
552 | * pwm_add_table() - register PWM device consumers | |
553 | * @table: array of consumers to register | |
554 | * @num: number of consumers in table | |
555 | */ | |
556 | void __init pwm_add_table(struct pwm_lookup *table, size_t num) | |
557 | { | |
558 | mutex_lock(&pwm_lookup_lock); | |
559 | ||
560 | while (num--) { | |
561 | list_add_tail(&table->list, &pwm_lookup_list); | |
562 | table++; | |
563 | } | |
564 | ||
565 | mutex_unlock(&pwm_lookup_lock); | |
566 | } | |
567 | ||
568 | /** | |
569 | * pwm_get() - look up and request a PWM device | |
570 | * @dev: device for PWM consumer | |
571 | * @con_id: consumer name | |
572 | * | |
7299ab70 TR |
573 | * Lookup is first attempted using DT. If the device was not instantiated from |
574 | * a device tree, a PWM chip and a relative index is looked up via a table | |
575 | * supplied by board setup code (see pwm_add_table()). | |
8138d2dd TR |
576 | * |
577 | * Once a PWM chip has been found the specified PWM device will be requested | |
578 | * and is ready to be used. | |
579 | */ | |
580 | struct pwm_device *pwm_get(struct device *dev, const char *con_id) | |
581 | { | |
582 | struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER); | |
e50d3523 | 583 | const char *dev_id = dev ? dev_name(dev) : NULL; |
8138d2dd | 584 | struct pwm_chip *chip = NULL; |
d295b129 | 585 | unsigned int index = 0; |
8138d2dd TR |
586 | unsigned int best = 0; |
587 | struct pwm_lookup *p; | |
8138d2dd TR |
588 | unsigned int match; |
589 | ||
7299ab70 TR |
590 | /* look up via DT first */ |
591 | if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) | |
8eb96127 | 592 | return of_pwm_get(dev->of_node, con_id); |
7299ab70 | 593 | |
8138d2dd TR |
594 | /* |
595 | * We look up the provider in the static table typically provided by | |
596 | * board setup code. We first try to lookup the consumer device by | |
597 | * name. If the consumer device was passed in as NULL or if no match | |
598 | * was found, we try to find the consumer by directly looking it up | |
599 | * by name. | |
600 | * | |
601 | * If a match is found, the provider PWM chip is looked up by name | |
602 | * and a PWM device is requested using the PWM device per-chip index. | |
603 | * | |
604 | * The lookup algorithm was shamelessly taken from the clock | |
605 | * framework: | |
606 | * | |
607 | * We do slightly fuzzy matching here: | |
608 | * An entry with a NULL ID is assumed to be a wildcard. | |
609 | * If an entry has a device ID, it must match | |
610 | * If an entry has a connection ID, it must match | |
611 | * Then we take the most specific entry - with the following order | |
612 | * of precedence: dev+con > dev only > con only. | |
613 | */ | |
614 | mutex_lock(&pwm_lookup_lock); | |
615 | ||
616 | list_for_each_entry(p, &pwm_lookup_list, list) { | |
617 | match = 0; | |
618 | ||
619 | if (p->dev_id) { | |
620 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
621 | continue; | |
622 | ||
623 | match += 2; | |
624 | } | |
625 | ||
626 | if (p->con_id) { | |
627 | if (!con_id || strcmp(p->con_id, con_id)) | |
628 | continue; | |
629 | ||
630 | match += 1; | |
631 | } | |
632 | ||
633 | if (match > best) { | |
634 | chip = pwmchip_find_by_name(p->provider); | |
635 | index = p->index; | |
636 | ||
637 | if (match != 3) | |
638 | best = match; | |
639 | else | |
640 | break; | |
641 | } | |
642 | } | |
643 | ||
644 | if (chip) | |
645 | pwm = pwm_request_from_chip(chip, index, con_id ?: dev_id); | |
646 | ||
647 | mutex_unlock(&pwm_lookup_lock); | |
648 | ||
649 | return pwm; | |
650 | } | |
651 | EXPORT_SYMBOL_GPL(pwm_get); | |
652 | ||
653 | /** | |
654 | * pwm_put() - release a PWM device | |
655 | * @pwm: PWM device | |
656 | */ | |
657 | void pwm_put(struct pwm_device *pwm) | |
658 | { | |
659 | if (!pwm) | |
660 | return; | |
661 | ||
662 | mutex_lock(&pwm_lock); | |
663 | ||
664 | if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { | |
e50d3523 | 665 | pr_warn("PWM device already freed\n"); |
8138d2dd TR |
666 | goto out; |
667 | } | |
668 | ||
669 | if (pwm->chip->ops->free) | |
670 | pwm->chip->ops->free(pwm->chip, pwm); | |
671 | ||
672 | pwm->label = NULL; | |
673 | ||
674 | module_put(pwm->chip->ops->owner); | |
675 | out: | |
676 | mutex_unlock(&pwm_lock); | |
677 | } | |
678 | EXPORT_SYMBOL_GPL(pwm_put); | |
679 | ||
6354316d AC |
680 | static void devm_pwm_release(struct device *dev, void *res) |
681 | { | |
682 | pwm_put(*(struct pwm_device **)res); | |
683 | } | |
684 | ||
685 | /** | |
686 | * devm_pwm_get() - resource managed pwm_get() | |
687 | * @dev: device for PWM consumer | |
688 | * @con_id: consumer name | |
689 | * | |
690 | * This function performs like pwm_get() but the acquired PWM device will | |
691 | * automatically be released on driver detach. | |
692 | */ | |
693 | struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id) | |
694 | { | |
695 | struct pwm_device **ptr, *pwm; | |
696 | ||
697 | ptr = devres_alloc(devm_pwm_release, sizeof(**ptr), GFP_KERNEL); | |
698 | if (!ptr) | |
699 | return ERR_PTR(-ENOMEM); | |
700 | ||
701 | pwm = pwm_get(dev, con_id); | |
702 | if (!IS_ERR(pwm)) { | |
703 | *ptr = pwm; | |
704 | devres_add(dev, ptr); | |
705 | } else { | |
706 | devres_free(ptr); | |
707 | } | |
708 | ||
709 | return pwm; | |
710 | } | |
711 | EXPORT_SYMBOL_GPL(devm_pwm_get); | |
712 | ||
261a5edd PU |
713 | /** |
714 | * devm_of_pwm_get() - resource managed of_pwm_get() | |
715 | * @dev: device for PWM consumer | |
716 | * @np: device node to get the PWM from | |
717 | * @con_id: consumer name | |
718 | * | |
719 | * This function performs like of_pwm_get() but the acquired PWM device will | |
720 | * automatically be released on driver detach. | |
721 | */ | |
722 | struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, | |
723 | const char *con_id) | |
724 | { | |
725 | struct pwm_device **ptr, *pwm; | |
726 | ||
727 | ptr = devres_alloc(devm_pwm_release, sizeof(**ptr), GFP_KERNEL); | |
728 | if (!ptr) | |
729 | return ERR_PTR(-ENOMEM); | |
730 | ||
731 | pwm = of_pwm_get(np, con_id); | |
732 | if (!IS_ERR(pwm)) { | |
733 | *ptr = pwm; | |
734 | devres_add(dev, ptr); | |
735 | } else { | |
736 | devres_free(ptr); | |
737 | } | |
738 | ||
739 | return pwm; | |
740 | } | |
741 | EXPORT_SYMBOL_GPL(devm_of_pwm_get); | |
742 | ||
6354316d AC |
743 | static int devm_pwm_match(struct device *dev, void *res, void *data) |
744 | { | |
745 | struct pwm_device **p = res; | |
746 | ||
747 | if (WARN_ON(!p || !*p)) | |
748 | return 0; | |
749 | ||
750 | return *p == data; | |
751 | } | |
752 | ||
753 | /** | |
754 | * devm_pwm_put() - resource managed pwm_put() | |
755 | * @dev: device for PWM consumer | |
756 | * @pwm: PWM device | |
757 | * | |
758 | * Release a PWM previously allocated using devm_pwm_get(). Calling this | |
759 | * function is usually not needed because devm-allocated resources are | |
760 | * automatically released on driver detach. | |
761 | */ | |
762 | void devm_pwm_put(struct device *dev, struct pwm_device *pwm) | |
763 | { | |
764 | WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm)); | |
765 | } | |
766 | EXPORT_SYMBOL_GPL(devm_pwm_put); | |
767 | ||
6e69ab13 FV |
768 | /** |
769 | * pwm_can_sleep() - report whether PWM access will sleep | |
770 | * @pwm: PWM device | |
771 | * | |
772 | * It returns true if accessing the PWM can sleep, false otherwise. | |
773 | */ | |
774 | bool pwm_can_sleep(struct pwm_device *pwm) | |
775 | { | |
776 | return pwm->chip->can_sleep; | |
777 | } | |
778 | EXPORT_SYMBOL_GPL(pwm_can_sleep); | |
779 | ||
62099abf TR |
780 | #ifdef CONFIG_DEBUG_FS |
781 | static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) | |
782 | { | |
783 | unsigned int i; | |
784 | ||
785 | for (i = 0; i < chip->npwm; i++) { | |
786 | struct pwm_device *pwm = &chip->pwms[i]; | |
787 | ||
788 | seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); | |
789 | ||
790 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
791 | seq_printf(s, " requested"); | |
792 | ||
793 | if (test_bit(PWMF_ENABLED, &pwm->flags)) | |
794 | seq_printf(s, " enabled"); | |
795 | ||
796 | seq_printf(s, "\n"); | |
797 | } | |
798 | } | |
799 | ||
800 | static void *pwm_seq_start(struct seq_file *s, loff_t *pos) | |
801 | { | |
802 | mutex_lock(&pwm_lock); | |
803 | s->private = ""; | |
804 | ||
805 | return seq_list_start(&pwm_chips, *pos); | |
806 | } | |
807 | ||
808 | static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
809 | { | |
810 | s->private = "\n"; | |
811 | ||
812 | return seq_list_next(v, &pwm_chips, pos); | |
813 | } | |
814 | ||
815 | static void pwm_seq_stop(struct seq_file *s, void *v) | |
816 | { | |
817 | mutex_unlock(&pwm_lock); | |
818 | } | |
819 | ||
820 | static int pwm_seq_show(struct seq_file *s, void *v) | |
821 | { | |
822 | struct pwm_chip *chip = list_entry(v, struct pwm_chip, list); | |
823 | ||
824 | seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private, | |
825 | chip->dev->bus ? chip->dev->bus->name : "no-bus", | |
826 | dev_name(chip->dev), chip->npwm, | |
827 | (chip->npwm != 1) ? "s" : ""); | |
828 | ||
829 | if (chip->ops->dbg_show) | |
830 | chip->ops->dbg_show(chip, s); | |
831 | else | |
832 | pwm_dbg_show(chip, s); | |
833 | ||
834 | return 0; | |
835 | } | |
836 | ||
837 | static const struct seq_operations pwm_seq_ops = { | |
838 | .start = pwm_seq_start, | |
839 | .next = pwm_seq_next, | |
840 | .stop = pwm_seq_stop, | |
841 | .show = pwm_seq_show, | |
842 | }; | |
843 | ||
844 | static int pwm_seq_open(struct inode *inode, struct file *file) | |
845 | { | |
846 | return seq_open(file, &pwm_seq_ops); | |
847 | } | |
848 | ||
849 | static const struct file_operations pwm_debugfs_ops = { | |
850 | .owner = THIS_MODULE, | |
851 | .open = pwm_seq_open, | |
852 | .read = seq_read, | |
853 | .llseek = seq_lseek, | |
854 | .release = seq_release, | |
855 | }; | |
856 | ||
857 | static int __init pwm_debugfs_init(void) | |
858 | { | |
859 | debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL, | |
860 | &pwm_debugfs_ops); | |
861 | ||
862 | return 0; | |
863 | } | |
864 | ||
865 | subsys_initcall(pwm_debugfs_init); | |
866 | #endif /* CONFIG_DEBUG_FS */ |