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 | |
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 | /** | |
226 | * pwmchip_add() - register a new PWM chip | |
227 | * @chip: the PWM chip to add | |
f051c466 TR |
228 | * |
229 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base | |
230 | * will be used. | |
0c2498f1 SH |
231 | */ |
232 | int pwmchip_add(struct pwm_chip *chip) | |
233 | { | |
234 | struct pwm_device *pwm; | |
f051c466 TR |
235 | unsigned int i; |
236 | int ret; | |
0c2498f1 | 237 | |
f051c466 | 238 | if (!chip || !chip->dev || !chip->ops || !chip->ops->config || |
533acc0e | 239 | !chip->ops->enable || !chip->ops->disable || !chip->npwm) |
f051c466 | 240 | return -EINVAL; |
0c2498f1 SH |
241 | |
242 | mutex_lock(&pwm_lock); | |
243 | ||
f051c466 TR |
244 | ret = alloc_pwms(chip->base, chip->npwm); |
245 | if (ret < 0) | |
246 | goto out; | |
247 | ||
248 | chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL); | |
249 | if (!chip->pwms) { | |
250 | ret = -ENOMEM; | |
0c2498f1 SH |
251 | goto out; |
252 | } | |
253 | ||
f051c466 TR |
254 | chip->base = ret; |
255 | ||
256 | for (i = 0; i < chip->npwm; i++) { | |
257 | pwm = &chip->pwms[i]; | |
258 | ||
259 | pwm->chip = chip; | |
260 | pwm->pwm = chip->base + i; | |
261 | pwm->hwpwm = i; | |
0c2498f1 | 262 | |
f051c466 TR |
263 | radix_tree_insert(&pwm_tree, pwm->pwm, pwm); |
264 | } | |
265 | ||
266 | bitmap_set(allocated_pwms, chip->base, chip->npwm); | |
267 | ||
268 | INIT_LIST_HEAD(&chip->list); | |
269 | list_add(&chip->list, &pwm_chips); | |
0c2498f1 | 270 | |
f051c466 TR |
271 | ret = 0; |
272 | ||
7299ab70 TR |
273 | if (IS_ENABLED(CONFIG_OF)) |
274 | of_pwmchip_add(chip); | |
275 | ||
76abbdde HS |
276 | pwmchip_sysfs_export(chip); |
277 | ||
f051c466 TR |
278 | out: |
279 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
280 | return ret; |
281 | } | |
282 | EXPORT_SYMBOL_GPL(pwmchip_add); | |
283 | ||
284 | /** | |
285 | * pwmchip_remove() - remove a PWM chip | |
286 | * @chip: the PWM chip to remove | |
287 | * | |
288 | * Removes a PWM chip. This function may return busy if the PWM chip provides | |
289 | * a PWM device that is still requested. | |
290 | */ | |
291 | int pwmchip_remove(struct pwm_chip *chip) | |
292 | { | |
f051c466 | 293 | unsigned int i; |
0c2498f1 SH |
294 | int ret = 0; |
295 | ||
296 | mutex_lock(&pwm_lock); | |
297 | ||
f051c466 TR |
298 | for (i = 0; i < chip->npwm; i++) { |
299 | struct pwm_device *pwm = &chip->pwms[i]; | |
0c2498f1 | 300 | |
f051c466 TR |
301 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) { |
302 | ret = -EBUSY; | |
303 | goto out; | |
304 | } | |
0c2498f1 SH |
305 | } |
306 | ||
f051c466 | 307 | list_del_init(&chip->list); |
7299ab70 TR |
308 | |
309 | if (IS_ENABLED(CONFIG_OF)) | |
310 | of_pwmchip_remove(chip); | |
311 | ||
f051c466 | 312 | free_pwms(chip); |
0c2498f1 | 313 | |
76abbdde HS |
314 | pwmchip_sysfs_unexport(chip); |
315 | ||
0c2498f1 SH |
316 | out: |
317 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
318 | return ret; |
319 | } | |
320 | EXPORT_SYMBOL_GPL(pwmchip_remove); | |
321 | ||
322 | /** | |
323 | * pwm_request() - request a PWM device | |
324 | * @pwm_id: global PWM device index | |
325 | * @label: PWM device label | |
8138d2dd TR |
326 | * |
327 | * This function is deprecated, use pwm_get() instead. | |
0c2498f1 | 328 | */ |
f051c466 | 329 | struct pwm_device *pwm_request(int pwm, const char *label) |
0c2498f1 | 330 | { |
f051c466 TR |
331 | struct pwm_device *dev; |
332 | int err; | |
333 | ||
334 | if (pwm < 0 || pwm >= MAX_PWMS) | |
335 | return ERR_PTR(-EINVAL); | |
0c2498f1 SH |
336 | |
337 | mutex_lock(&pwm_lock); | |
338 | ||
f051c466 TR |
339 | dev = pwm_to_device(pwm); |
340 | if (!dev) { | |
341 | dev = ERR_PTR(-EPROBE_DEFER); | |
0c2498f1 SH |
342 | goto out; |
343 | } | |
344 | ||
f051c466 TR |
345 | err = pwm_device_request(dev, label); |
346 | if (err < 0) | |
347 | dev = ERR_PTR(err); | |
0c2498f1 | 348 | |
f051c466 TR |
349 | out: |
350 | mutex_unlock(&pwm_lock); | |
0c2498f1 | 351 | |
f051c466 TR |
352 | return dev; |
353 | } | |
354 | EXPORT_SYMBOL_GPL(pwm_request); | |
0c2498f1 | 355 | |
f051c466 TR |
356 | /** |
357 | * pwm_request_from_chip() - request a PWM device relative to a PWM chip | |
358 | * @chip: PWM chip | |
359 | * @index: per-chip index of the PWM to request | |
360 | * @label: a literal description string of this PWM | |
361 | * | |
362 | * Returns the PWM at the given index of the given PWM chip. A negative error | |
363 | * code is returned if the index is not valid for the specified PWM chip or | |
364 | * if the PWM device cannot be requested. | |
365 | */ | |
366 | struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, | |
367 | unsigned int index, | |
368 | const char *label) | |
369 | { | |
370 | struct pwm_device *pwm; | |
371 | int err; | |
0c2498f1 | 372 | |
f051c466 TR |
373 | if (!chip || index >= chip->npwm) |
374 | return ERR_PTR(-EINVAL); | |
0c2498f1 | 375 | |
f051c466 TR |
376 | mutex_lock(&pwm_lock); |
377 | pwm = &chip->pwms[index]; | |
0c2498f1 | 378 | |
f051c466 TR |
379 | err = pwm_device_request(pwm, label); |
380 | if (err < 0) | |
381 | pwm = ERR_PTR(err); | |
382 | ||
383 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
384 | return pwm; |
385 | } | |
f051c466 | 386 | EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
0c2498f1 SH |
387 | |
388 | /** | |
389 | * pwm_free() - free a PWM device | |
390 | * @pwm: PWM device | |
8138d2dd TR |
391 | * |
392 | * This function is deprecated, use pwm_put() instead. | |
0c2498f1 SH |
393 | */ |
394 | void pwm_free(struct pwm_device *pwm) | |
395 | { | |
8138d2dd | 396 | pwm_put(pwm); |
0c2498f1 SH |
397 | } |
398 | EXPORT_SYMBOL_GPL(pwm_free); | |
399 | ||
400 | /** | |
401 | * pwm_config() - change a PWM device configuration | |
402 | * @pwm: PWM device | |
403 | * @duty_ns: "on" time (in nanoseconds) | |
404 | * @period_ns: duration (in nanoseconds) of one cycle | |
405 | */ | |
406 | int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) | |
407 | { | |
76abbdde HS |
408 | int err; |
409 | ||
c2d476a9 | 410 | if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns) |
f051c466 TR |
411 | return -EINVAL; |
412 | ||
76abbdde HS |
413 | err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); |
414 | if (err) | |
415 | return err; | |
416 | ||
417 | pwm->duty_cycle = duty_ns; | |
418 | pwm->period = period_ns; | |
419 | ||
420 | return 0; | |
0c2498f1 SH |
421 | } |
422 | EXPORT_SYMBOL_GPL(pwm_config); | |
423 | ||
0aa0869c PA |
424 | /** |
425 | * pwm_set_polarity() - configure the polarity of a PWM signal | |
426 | * @pwm: PWM device | |
427 | * @polarity: new polarity of the PWM signal | |
428 | * | |
429 | * Note that the polarity cannot be configured while the PWM device is enabled | |
430 | */ | |
431 | int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) | |
432 | { | |
76abbdde HS |
433 | int err; |
434 | ||
0aa0869c PA |
435 | if (!pwm || !pwm->chip->ops) |
436 | return -EINVAL; | |
437 | ||
438 | if (!pwm->chip->ops->set_polarity) | |
439 | return -ENOSYS; | |
440 | ||
441 | if (test_bit(PWMF_ENABLED, &pwm->flags)) | |
442 | return -EBUSY; | |
443 | ||
76abbdde HS |
444 | err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity); |
445 | if (err) | |
446 | return err; | |
447 | ||
448 | pwm->polarity = polarity; | |
449 | ||
450 | return 0; | |
0aa0869c PA |
451 | } |
452 | EXPORT_SYMBOL_GPL(pwm_set_polarity); | |
453 | ||
0c2498f1 SH |
454 | /** |
455 | * pwm_enable() - start a PWM output toggling | |
456 | * @pwm: PWM device | |
457 | */ | |
458 | int pwm_enable(struct pwm_device *pwm) | |
459 | { | |
f051c466 TR |
460 | if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags)) |
461 | return pwm->chip->ops->enable(pwm->chip, pwm); | |
0c2498f1 | 462 | |
f051c466 | 463 | return pwm ? 0 : -EINVAL; |
0c2498f1 SH |
464 | } |
465 | EXPORT_SYMBOL_GPL(pwm_enable); | |
466 | ||
467 | /** | |
468 | * pwm_disable() - stop a PWM output toggling | |
469 | * @pwm: PWM device | |
470 | */ | |
471 | void pwm_disable(struct pwm_device *pwm) | |
472 | { | |
f051c466 TR |
473 | if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags)) |
474 | pwm->chip->ops->disable(pwm->chip, pwm); | |
0c2498f1 SH |
475 | } |
476 | EXPORT_SYMBOL_GPL(pwm_disable); | |
62099abf | 477 | |
7299ab70 TR |
478 | static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) |
479 | { | |
480 | struct pwm_chip *chip; | |
481 | ||
482 | mutex_lock(&pwm_lock); | |
483 | ||
484 | list_for_each_entry(chip, &pwm_chips, list) | |
485 | if (chip->dev && chip->dev->of_node == np) { | |
486 | mutex_unlock(&pwm_lock); | |
487 | return chip; | |
488 | } | |
489 | ||
490 | mutex_unlock(&pwm_lock); | |
491 | ||
492 | return ERR_PTR(-EPROBE_DEFER); | |
493 | } | |
494 | ||
495 | /** | |
8eb96127 | 496 | * of_pwm_get() - request a PWM via the PWM framework |
7299ab70 TR |
497 | * @np: device node to get the PWM from |
498 | * @con_id: consumer name | |
499 | * | |
500 | * Returns the PWM device parsed from the phandle and index specified in the | |
501 | * "pwms" property of a device tree node or a negative error-code on failure. | |
502 | * Values parsed from the device tree are stored in the returned PWM device | |
503 | * object. | |
504 | * | |
505 | * If con_id is NULL, the first PWM device listed in the "pwms" property will | |
506 | * be requested. Otherwise the "pwm-names" property is used to do a reverse | |
507 | * lookup of the PWM index. This also means that the "pwm-names" property | |
508 | * becomes mandatory for devices that look up the PWM device via the con_id | |
509 | * parameter. | |
510 | */ | |
8eb96127 | 511 | struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) |
7299ab70 TR |
512 | { |
513 | struct pwm_device *pwm = NULL; | |
514 | struct of_phandle_args args; | |
515 | struct pwm_chip *pc; | |
516 | int index = 0; | |
517 | int err; | |
518 | ||
519 | if (con_id) { | |
520 | index = of_property_match_string(np, "pwm-names", con_id); | |
521 | if (index < 0) | |
522 | return ERR_PTR(index); | |
523 | } | |
524 | ||
525 | err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, | |
526 | &args); | |
527 | if (err) { | |
528 | pr_debug("%s(): can't parse \"pwms\" property\n", __func__); | |
529 | return ERR_PTR(err); | |
530 | } | |
531 | ||
532 | pc = of_node_to_pwmchip(args.np); | |
533 | if (IS_ERR(pc)) { | |
534 | pr_debug("%s(): PWM chip not found\n", __func__); | |
535 | pwm = ERR_CAST(pc); | |
536 | goto put; | |
537 | } | |
538 | ||
539 | if (args.args_count != pc->of_pwm_n_cells) { | |
540 | pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name, | |
541 | args.np->full_name); | |
542 | pwm = ERR_PTR(-EINVAL); | |
543 | goto put; | |
544 | } | |
545 | ||
546 | pwm = pc->of_xlate(pc, &args); | |
547 | if (IS_ERR(pwm)) | |
548 | goto put; | |
549 | ||
550 | /* | |
551 | * If a consumer name was not given, try to look it up from the | |
552 | * "pwm-names" property if it exists. Otherwise use the name of | |
553 | * the user device node. | |
554 | */ | |
555 | if (!con_id) { | |
556 | err = of_property_read_string_index(np, "pwm-names", index, | |
557 | &con_id); | |
558 | if (err < 0) | |
559 | con_id = np->name; | |
560 | } | |
561 | ||
562 | pwm->label = con_id; | |
563 | ||
564 | put: | |
565 | of_node_put(args.np); | |
566 | ||
567 | return pwm; | |
568 | } | |
8eb96127 | 569 | EXPORT_SYMBOL_GPL(of_pwm_get); |
7299ab70 | 570 | |
8138d2dd TR |
571 | /** |
572 | * pwm_add_table() - register PWM device consumers | |
573 | * @table: array of consumers to register | |
574 | * @num: number of consumers in table | |
575 | */ | |
576 | void __init pwm_add_table(struct pwm_lookup *table, size_t num) | |
577 | { | |
578 | mutex_lock(&pwm_lookup_lock); | |
579 | ||
580 | while (num--) { | |
581 | list_add_tail(&table->list, &pwm_lookup_list); | |
582 | table++; | |
583 | } | |
584 | ||
585 | mutex_unlock(&pwm_lookup_lock); | |
586 | } | |
587 | ||
588 | /** | |
589 | * pwm_get() - look up and request a PWM device | |
590 | * @dev: device for PWM consumer | |
591 | * @con_id: consumer name | |
592 | * | |
7299ab70 TR |
593 | * Lookup is first attempted using DT. If the device was not instantiated from |
594 | * a device tree, a PWM chip and a relative index is looked up via a table | |
595 | * supplied by board setup code (see pwm_add_table()). | |
8138d2dd TR |
596 | * |
597 | * Once a PWM chip has been found the specified PWM device will be requested | |
598 | * and is ready to be used. | |
599 | */ | |
600 | struct pwm_device *pwm_get(struct device *dev, const char *con_id) | |
601 | { | |
602 | struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER); | |
e50d3523 | 603 | const char *dev_id = dev ? dev_name(dev) : NULL; |
8138d2dd TR |
604 | struct pwm_chip *chip = NULL; |
605 | unsigned int best = 0; | |
70145f87 | 606 | struct pwm_lookup *p, *chosen = NULL; |
8138d2dd TR |
607 | unsigned int match; |
608 | ||
7299ab70 TR |
609 | /* look up via DT first */ |
610 | if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) | |
8eb96127 | 611 | return of_pwm_get(dev->of_node, con_id); |
7299ab70 | 612 | |
8138d2dd TR |
613 | /* |
614 | * We look up the provider in the static table typically provided by | |
615 | * board setup code. We first try to lookup the consumer device by | |
616 | * name. If the consumer device was passed in as NULL or if no match | |
617 | * was found, we try to find the consumer by directly looking it up | |
618 | * by name. | |
619 | * | |
620 | * If a match is found, the provider PWM chip is looked up by name | |
621 | * and a PWM device is requested using the PWM device per-chip index. | |
622 | * | |
623 | * The lookup algorithm was shamelessly taken from the clock | |
624 | * framework: | |
625 | * | |
626 | * We do slightly fuzzy matching here: | |
627 | * An entry with a NULL ID is assumed to be a wildcard. | |
628 | * If an entry has a device ID, it must match | |
629 | * If an entry has a connection ID, it must match | |
630 | * Then we take the most specific entry - with the following order | |
631 | * of precedence: dev+con > dev only > con only. | |
632 | */ | |
633 | mutex_lock(&pwm_lookup_lock); | |
634 | ||
635 | list_for_each_entry(p, &pwm_lookup_list, list) { | |
636 | match = 0; | |
637 | ||
638 | if (p->dev_id) { | |
639 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
640 | continue; | |
641 | ||
642 | match += 2; | |
643 | } | |
644 | ||
645 | if (p->con_id) { | |
646 | if (!con_id || strcmp(p->con_id, con_id)) | |
647 | continue; | |
648 | ||
649 | match += 1; | |
650 | } | |
651 | ||
652 | if (match > best) { | |
70145f87 | 653 | chosen = p; |
8138d2dd TR |
654 | |
655 | if (match != 3) | |
656 | best = match; | |
657 | else | |
658 | break; | |
659 | } | |
660 | } | |
661 | ||
70145f87 GU |
662 | if (!chosen) |
663 | goto out; | |
3796ce1d | 664 | |
70145f87 GU |
665 | chip = pwmchip_find_by_name(chosen->provider); |
666 | if (!chip) | |
667 | goto out; | |
3796ce1d | 668 | |
70145f87 GU |
669 | pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id); |
670 | if (IS_ERR(pwm)) | |
671 | goto out; | |
8138d2dd | 672 | |
70145f87 GU |
673 | pwm_set_period(pwm, chosen->period); |
674 | pwm_set_polarity(pwm, chosen->polarity); | |
8138d2dd | 675 | |
70145f87 GU |
676 | out: |
677 | mutex_unlock(&pwm_lookup_lock); | |
8138d2dd TR |
678 | return pwm; |
679 | } | |
680 | EXPORT_SYMBOL_GPL(pwm_get); | |
681 | ||
682 | /** | |
683 | * pwm_put() - release a PWM device | |
684 | * @pwm: PWM device | |
685 | */ | |
686 | void pwm_put(struct pwm_device *pwm) | |
687 | { | |
688 | if (!pwm) | |
689 | return; | |
690 | ||
691 | mutex_lock(&pwm_lock); | |
692 | ||
693 | if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { | |
e50d3523 | 694 | pr_warn("PWM device already freed\n"); |
8138d2dd TR |
695 | goto out; |
696 | } | |
697 | ||
698 | if (pwm->chip->ops->free) | |
699 | pwm->chip->ops->free(pwm->chip, pwm); | |
700 | ||
701 | pwm->label = NULL; | |
702 | ||
703 | module_put(pwm->chip->ops->owner); | |
704 | out: | |
705 | mutex_unlock(&pwm_lock); | |
706 | } | |
707 | EXPORT_SYMBOL_GPL(pwm_put); | |
708 | ||
6354316d AC |
709 | static void devm_pwm_release(struct device *dev, void *res) |
710 | { | |
711 | pwm_put(*(struct pwm_device **)res); | |
712 | } | |
713 | ||
714 | /** | |
715 | * devm_pwm_get() - resource managed pwm_get() | |
716 | * @dev: device for PWM consumer | |
717 | * @con_id: consumer name | |
718 | * | |
719 | * This function performs like pwm_get() but the acquired PWM device will | |
720 | * automatically be released on driver detach. | |
721 | */ | |
722 | struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id) | |
723 | { | |
724 | struct pwm_device **ptr, *pwm; | |
725 | ||
77f0b9d2 | 726 | ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL); |
6354316d AC |
727 | if (!ptr) |
728 | return ERR_PTR(-ENOMEM); | |
729 | ||
730 | pwm = pwm_get(dev, con_id); | |
731 | if (!IS_ERR(pwm)) { | |
732 | *ptr = pwm; | |
733 | devres_add(dev, ptr); | |
734 | } else { | |
735 | devres_free(ptr); | |
736 | } | |
737 | ||
738 | return pwm; | |
739 | } | |
740 | EXPORT_SYMBOL_GPL(devm_pwm_get); | |
741 | ||
261a5edd PU |
742 | /** |
743 | * devm_of_pwm_get() - resource managed of_pwm_get() | |
744 | * @dev: device for PWM consumer | |
745 | * @np: device node to get the PWM from | |
746 | * @con_id: consumer name | |
747 | * | |
748 | * This function performs like of_pwm_get() but the acquired PWM device will | |
749 | * automatically be released on driver detach. | |
750 | */ | |
751 | struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, | |
752 | const char *con_id) | |
753 | { | |
754 | struct pwm_device **ptr, *pwm; | |
755 | ||
77f0b9d2 | 756 | ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL); |
261a5edd PU |
757 | if (!ptr) |
758 | return ERR_PTR(-ENOMEM); | |
759 | ||
760 | pwm = of_pwm_get(np, con_id); | |
761 | if (!IS_ERR(pwm)) { | |
762 | *ptr = pwm; | |
763 | devres_add(dev, ptr); | |
764 | } else { | |
765 | devres_free(ptr); | |
766 | } | |
767 | ||
768 | return pwm; | |
769 | } | |
770 | EXPORT_SYMBOL_GPL(devm_of_pwm_get); | |
771 | ||
6354316d AC |
772 | static int devm_pwm_match(struct device *dev, void *res, void *data) |
773 | { | |
774 | struct pwm_device **p = res; | |
775 | ||
776 | if (WARN_ON(!p || !*p)) | |
777 | return 0; | |
778 | ||
779 | return *p == data; | |
780 | } | |
781 | ||
782 | /** | |
783 | * devm_pwm_put() - resource managed pwm_put() | |
784 | * @dev: device for PWM consumer | |
785 | * @pwm: PWM device | |
786 | * | |
787 | * Release a PWM previously allocated using devm_pwm_get(). Calling this | |
788 | * function is usually not needed because devm-allocated resources are | |
789 | * automatically released on driver detach. | |
790 | */ | |
791 | void devm_pwm_put(struct device *dev, struct pwm_device *pwm) | |
792 | { | |
793 | WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm)); | |
794 | } | |
795 | EXPORT_SYMBOL_GPL(devm_pwm_put); | |
796 | ||
6e69ab13 FV |
797 | /** |
798 | * pwm_can_sleep() - report whether PWM access will sleep | |
799 | * @pwm: PWM device | |
800 | * | |
801 | * It returns true if accessing the PWM can sleep, false otherwise. | |
802 | */ | |
803 | bool pwm_can_sleep(struct pwm_device *pwm) | |
804 | { | |
805 | return pwm->chip->can_sleep; | |
806 | } | |
807 | EXPORT_SYMBOL_GPL(pwm_can_sleep); | |
808 | ||
62099abf TR |
809 | #ifdef CONFIG_DEBUG_FS |
810 | static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) | |
811 | { | |
812 | unsigned int i; | |
813 | ||
814 | for (i = 0; i < chip->npwm; i++) { | |
815 | struct pwm_device *pwm = &chip->pwms[i]; | |
816 | ||
817 | seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); | |
818 | ||
819 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
adcba1e3 | 820 | seq_puts(s, " requested"); |
62099abf TR |
821 | |
822 | if (test_bit(PWMF_ENABLED, &pwm->flags)) | |
adcba1e3 | 823 | seq_puts(s, " enabled"); |
62099abf | 824 | |
adcba1e3 | 825 | seq_puts(s, "\n"); |
62099abf TR |
826 | } |
827 | } | |
828 | ||
829 | static void *pwm_seq_start(struct seq_file *s, loff_t *pos) | |
830 | { | |
831 | mutex_lock(&pwm_lock); | |
832 | s->private = ""; | |
833 | ||
834 | return seq_list_start(&pwm_chips, *pos); | |
835 | } | |
836 | ||
837 | static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
838 | { | |
839 | s->private = "\n"; | |
840 | ||
841 | return seq_list_next(v, &pwm_chips, pos); | |
842 | } | |
843 | ||
844 | static void pwm_seq_stop(struct seq_file *s, void *v) | |
845 | { | |
846 | mutex_unlock(&pwm_lock); | |
847 | } | |
848 | ||
849 | static int pwm_seq_show(struct seq_file *s, void *v) | |
850 | { | |
851 | struct pwm_chip *chip = list_entry(v, struct pwm_chip, list); | |
852 | ||
853 | seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private, | |
854 | chip->dev->bus ? chip->dev->bus->name : "no-bus", | |
855 | dev_name(chip->dev), chip->npwm, | |
856 | (chip->npwm != 1) ? "s" : ""); | |
857 | ||
858 | if (chip->ops->dbg_show) | |
859 | chip->ops->dbg_show(chip, s); | |
860 | else | |
861 | pwm_dbg_show(chip, s); | |
862 | ||
863 | return 0; | |
864 | } | |
865 | ||
866 | static const struct seq_operations pwm_seq_ops = { | |
867 | .start = pwm_seq_start, | |
868 | .next = pwm_seq_next, | |
869 | .stop = pwm_seq_stop, | |
870 | .show = pwm_seq_show, | |
871 | }; | |
872 | ||
873 | static int pwm_seq_open(struct inode *inode, struct file *file) | |
874 | { | |
875 | return seq_open(file, &pwm_seq_ops); | |
876 | } | |
877 | ||
878 | static const struct file_operations pwm_debugfs_ops = { | |
879 | .owner = THIS_MODULE, | |
880 | .open = pwm_seq_open, | |
881 | .read = seq_read, | |
882 | .llseek = seq_lseek, | |
883 | .release = seq_release, | |
884 | }; | |
885 | ||
886 | static int __init pwm_debugfs_init(void) | |
887 | { | |
888 | debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL, | |
889 | &pwm_debugfs_ops); | |
890 | ||
891 | return 0; | |
892 | } | |
893 | ||
894 | subsys_initcall(pwm_debugfs_init); | |
895 | #endif /* CONFIG_DEBUG_FS */ |