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1a189b97 RK |
1 | #ifndef __LINUX_PWM_H |
2 | #define __LINUX_PWM_H | |
3 | ||
0bcf168b | 4 | #include <linux/err.h> |
d1cd2142 | 5 | #include <linux/mutex.h> |
7299ab70 TR |
6 | #include <linux/of.h> |
7 | ||
3a3d1a4e | 8 | struct pwm_capture; |
62099abf | 9 | struct seq_file; |
3a3d1a4e | 10 | |
0c2498f1 SH |
11 | struct pwm_chip; |
12 | ||
0aa0869c PA |
13 | /** |
14 | * enum pwm_polarity - polarity of a PWM signal | |
15 | * @PWM_POLARITY_NORMAL: a high signal for the duration of the duty- | |
16 | * cycle, followed by a low signal for the remainder of the pulse | |
17 | * period | |
18 | * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty- | |
19 | * cycle, followed by a high signal for the remainder of the pulse | |
20 | * period | |
21 | */ | |
22 | enum pwm_polarity { | |
23 | PWM_POLARITY_NORMAL, | |
24 | PWM_POLARITY_INVERSED, | |
25 | }; | |
26 | ||
e39c0df1 BB |
27 | /** |
28 | * struct pwm_args - board-dependent PWM arguments | |
29 | * @period: reference period | |
30 | * @polarity: reference polarity | |
31 | * | |
32 | * This structure describes board-dependent arguments attached to a PWM | |
33 | * device. These arguments are usually retrieved from the PWM lookup table or | |
34 | * device tree. | |
35 | * | |
36 | * Do not confuse this with the PWM state: PWM arguments represent the initial | |
37 | * configuration that users want to use on this PWM device rather than the | |
38 | * current PWM hardware state. | |
39 | */ | |
40 | struct pwm_args { | |
41 | unsigned int period; | |
42 | enum pwm_polarity polarity; | |
43 | }; | |
44 | ||
f051c466 TR |
45 | enum { |
46 | PWMF_REQUESTED = 1 << 0, | |
09a7e4a3 | 47 | PWMF_EXPORTED = 1 << 1, |
f051c466 TR |
48 | }; |
49 | ||
43a276b0 BB |
50 | /* |
51 | * struct pwm_state - state of a PWM channel | |
52 | * @period: PWM period (in nanoseconds) | |
53 | * @duty_cycle: PWM duty cycle (in nanoseconds) | |
54 | * @polarity: PWM polarity | |
09a7e4a3 | 55 | * @enabled: PWM enabled status |
43a276b0 BB |
56 | */ |
57 | struct pwm_state { | |
58 | unsigned int period; | |
59 | unsigned int duty_cycle; | |
60 | enum pwm_polarity polarity; | |
09a7e4a3 | 61 | bool enabled; |
43a276b0 BB |
62 | }; |
63 | ||
04883802 TR |
64 | /** |
65 | * struct pwm_device - PWM channel object | |
66 | * @label: name of the PWM device | |
67 | * @flags: flags associated with the PWM device | |
68 | * @hwpwm: per-chip relative index of the PWM device | |
69 | * @pwm: global index of the PWM device | |
70 | * @chip: PWM chip providing this PWM device | |
71 | * @chip_data: chip-private data associated with the PWM device | |
e39c0df1 | 72 | * @args: PWM arguments |
43a276b0 | 73 | * @state: curent PWM channel state |
04883802 | 74 | */ |
f051c466 | 75 | struct pwm_device { |
6bc7064a TR |
76 | const char *label; |
77 | unsigned long flags; | |
78 | unsigned int hwpwm; | |
79 | unsigned int pwm; | |
80 | struct pwm_chip *chip; | |
81 | void *chip_data; | |
82 | ||
e39c0df1 | 83 | struct pwm_args args; |
43a276b0 | 84 | struct pwm_state state; |
f051c466 TR |
85 | }; |
86 | ||
43a276b0 BB |
87 | /** |
88 | * pwm_get_state() - retrieve the current PWM state | |
89 | * @pwm: PWM device | |
90 | * @state: state to fill with the current PWM state | |
91 | */ | |
92 | static inline void pwm_get_state(const struct pwm_device *pwm, | |
93 | struct pwm_state *state) | |
94 | { | |
95 | *state = pwm->state; | |
96 | } | |
97 | ||
5c31252c BB |
98 | static inline bool pwm_is_enabled(const struct pwm_device *pwm) |
99 | { | |
09a7e4a3 BB |
100 | struct pwm_state state; |
101 | ||
102 | pwm_get_state(pwm, &state); | |
103 | ||
104 | return state.enabled; | |
5c31252c BB |
105 | } |
106 | ||
f051c466 TR |
107 | static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period) |
108 | { | |
109 | if (pwm) | |
43a276b0 | 110 | pwm->state.period = period; |
f051c466 TR |
111 | } |
112 | ||
a1cf4217 | 113 | static inline unsigned int pwm_get_period(const struct pwm_device *pwm) |
f051c466 | 114 | { |
43a276b0 BB |
115 | struct pwm_state state; |
116 | ||
117 | pwm_get_state(pwm, &state); | |
118 | ||
119 | return state.period; | |
f051c466 TR |
120 | } |
121 | ||
76abbdde HS |
122 | static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty) |
123 | { | |
124 | if (pwm) | |
43a276b0 | 125 | pwm->state.duty_cycle = duty; |
76abbdde HS |
126 | } |
127 | ||
a1cf4217 | 128 | static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm) |
76abbdde | 129 | { |
43a276b0 BB |
130 | struct pwm_state state; |
131 | ||
132 | pwm_get_state(pwm, &state); | |
133 | ||
134 | return state.duty_cycle; | |
76abbdde HS |
135 | } |
136 | ||
011e7631 BB |
137 | static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm) |
138 | { | |
43a276b0 BB |
139 | struct pwm_state state; |
140 | ||
141 | pwm_get_state(pwm, &state); | |
142 | ||
143 | return state.polarity; | |
011e7631 BB |
144 | } |
145 | ||
e39c0df1 BB |
146 | static inline void pwm_get_args(const struct pwm_device *pwm, |
147 | struct pwm_args *args) | |
148 | { | |
149 | *args = pwm->args; | |
150 | } | |
151 | ||
a6a0dbbc BB |
152 | /** |
153 | * pwm_init_state() - prepare a new state to be applied with pwm_apply_state() | |
154 | * @pwm: PWM device | |
155 | * @state: state to fill with the prepared PWM state | |
156 | * | |
157 | * This functions prepares a state that can later be tweaked and applied | |
158 | * to the PWM device with pwm_apply_state(). This is a convenient function | |
159 | * that first retrieves the current PWM state and the replaces the period | |
160 | * and polarity fields with the reference values defined in pwm->args. | |
161 | * Once the function returns, you can adjust the ->enabled and ->duty_cycle | |
162 | * fields according to your needs before calling pwm_apply_state(). | |
163 | * | |
164 | * ->duty_cycle is initially set to zero to avoid cases where the current | |
165 | * ->duty_cycle value exceed the pwm_args->period one, which would trigger | |
166 | * an error if the user calls pwm_apply_state() without adjusting ->duty_cycle | |
167 | * first. | |
168 | */ | |
169 | static inline void pwm_init_state(const struct pwm_device *pwm, | |
170 | struct pwm_state *state) | |
171 | { | |
172 | struct pwm_args args; | |
173 | ||
174 | /* First get the current state. */ | |
175 | pwm_get_state(pwm, state); | |
176 | ||
177 | /* Then fill it with the reference config */ | |
178 | pwm_get_args(pwm, &args); | |
179 | ||
180 | state->period = args.period; | |
181 | state->polarity = args.polarity; | |
182 | state->duty_cycle = 0; | |
183 | } | |
184 | ||
f6f3bddf BB |
185 | /** |
186 | * pwm_get_relative_duty_cycle() - Get a relative duty cycle value | |
187 | * @state: PWM state to extract the duty cycle from | |
188 | * @scale: target scale of the relative duty cycle | |
189 | * | |
190 | * This functions converts the absolute duty cycle stored in @state (expressed | |
191 | * in nanosecond) into a value relative to the period. | |
192 | * | |
193 | * For example if you want to get the duty_cycle expressed in percent, call: | |
194 | * | |
195 | * pwm_get_state(pwm, &state); | |
196 | * duty = pwm_get_relative_duty_cycle(&state, 100); | |
197 | */ | |
198 | static inline unsigned int | |
199 | pwm_get_relative_duty_cycle(const struct pwm_state *state, unsigned int scale) | |
200 | { | |
201 | if (!state->period) | |
202 | return 0; | |
203 | ||
204 | return DIV_ROUND_CLOSEST_ULL((u64)state->duty_cycle * scale, | |
205 | state->period); | |
206 | } | |
207 | ||
208 | /** | |
209 | * pwm_set_relative_duty_cycle() - Set a relative duty cycle value | |
210 | * @state: PWM state to fill | |
211 | * @duty_cycle: relative duty cycle value | |
212 | * @scale: scale in which @duty_cycle is expressed | |
213 | * | |
214 | * This functions converts a relative into an absolute duty cycle (expressed | |
215 | * in nanoseconds), and puts the result in state->duty_cycle. | |
216 | * | |
217 | * For example if you want to configure a 50% duty cycle, call: | |
218 | * | |
219 | * pwm_init_state(pwm, &state); | |
220 | * pwm_set_relative_duty_cycle(&state, 50, 100); | |
221 | * pwm_apply_state(pwm, &state); | |
222 | * | |
223 | * This functions returns -EINVAL if @duty_cycle and/or @scale are | |
224 | * inconsistent (@scale == 0 or @duty_cycle > @scale). | |
225 | */ | |
226 | static inline int | |
227 | pwm_set_relative_duty_cycle(struct pwm_state *state, unsigned int duty_cycle, | |
228 | unsigned int scale) | |
229 | { | |
230 | if (!scale || duty_cycle > scale) | |
231 | return -EINVAL; | |
232 | ||
233 | state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)duty_cycle * | |
234 | state->period, | |
235 | scale); | |
236 | ||
237 | return 0; | |
238 | } | |
239 | ||
0c2498f1 SH |
240 | /** |
241 | * struct pwm_ops - PWM controller operations | |
242 | * @request: optional hook for requesting a PWM | |
243 | * @free: optional hook for freeing a PWM | |
244 | * @config: configure duty cycles and period length for this PWM | |
0aa0869c | 245 | * @set_polarity: configure the polarity of this PWM |
3a3d1a4e | 246 | * @capture: capture and report PWM signal |
0c2498f1 SH |
247 | * @enable: enable PWM output toggling |
248 | * @disable: disable PWM output toggling | |
5ec803ed BB |
249 | * @apply: atomically apply a new PWM config. The state argument |
250 | * should be adjusted with the real hardware config (if the | |
251 | * approximate the period or duty_cycle value, state should | |
252 | * reflect it) | |
15fa8a43 BB |
253 | * @get_state: get the current PWM state. This function is only |
254 | * called once per PWM device when the PWM chip is | |
255 | * registered. | |
62099abf | 256 | * @dbg_show: optional routine to show contents in debugfs |
0c2498f1 SH |
257 | * @owner: helps prevent removal of modules exporting active PWMs |
258 | */ | |
259 | struct pwm_ops { | |
6bc7064a TR |
260 | int (*request)(struct pwm_chip *chip, struct pwm_device *pwm); |
261 | void (*free)(struct pwm_chip *chip, struct pwm_device *pwm); | |
262 | int (*config)(struct pwm_chip *chip, struct pwm_device *pwm, | |
263 | int duty_ns, int period_ns); | |
264 | int (*set_polarity)(struct pwm_chip *chip, struct pwm_device *pwm, | |
265 | enum pwm_polarity polarity); | |
3a3d1a4e LJ |
266 | int (*capture)(struct pwm_chip *chip, struct pwm_device *pwm, |
267 | struct pwm_capture *result, unsigned long timeout); | |
6bc7064a TR |
268 | int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm); |
269 | void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm); | |
5ec803ed BB |
270 | int (*apply)(struct pwm_chip *chip, struct pwm_device *pwm, |
271 | struct pwm_state *state); | |
15fa8a43 BB |
272 | void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm, |
273 | struct pwm_state *state); | |
62099abf | 274 | #ifdef CONFIG_DEBUG_FS |
6bc7064a | 275 | void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s); |
62099abf | 276 | #endif |
6bc7064a | 277 | struct module *owner; |
0c2498f1 SH |
278 | }; |
279 | ||
280 | /** | |
f051c466 TR |
281 | * struct pwm_chip - abstract a PWM controller |
282 | * @dev: device providing the PWMs | |
283 | * @list: list node for internal use | |
284 | * @ops: callbacks for this PWM controller | |
285 | * @base: number of first PWM controlled by this chip | |
286 | * @npwm: number of PWMs controlled by this chip | |
287 | * @pwms: array of PWM devices allocated by the framework | |
04883802 TR |
288 | * @of_xlate: request a PWM device given a device tree PWM specifier |
289 | * @of_pwm_n_cells: number of cells expected in the device tree PWM specifier | |
0c2498f1 SH |
290 | */ |
291 | struct pwm_chip { | |
6bc7064a TR |
292 | struct device *dev; |
293 | struct list_head list; | |
294 | const struct pwm_ops *ops; | |
295 | int base; | |
296 | unsigned int npwm; | |
297 | ||
298 | struct pwm_device *pwms; | |
299 | ||
300 | struct pwm_device * (*of_xlate)(struct pwm_chip *pc, | |
301 | const struct of_phandle_args *args); | |
302 | unsigned int of_pwm_n_cells; | |
0c2498f1 SH |
303 | }; |
304 | ||
3a3d1a4e LJ |
305 | /** |
306 | * struct pwm_capture - PWM capture data | |
307 | * @period: period of the PWM signal (in nanoseconds) | |
308 | * @duty_cycle: duty cycle of the PWM signal (in nanoseconds) | |
309 | */ | |
310 | struct pwm_capture { | |
311 | unsigned int period; | |
312 | unsigned int duty_cycle; | |
313 | }; | |
314 | ||
0bcf168b | 315 | #if IS_ENABLED(CONFIG_PWM) |
5ec803ed BB |
316 | /* PWM user APIs */ |
317 | struct pwm_device *pwm_request(int pwm_id, const char *label); | |
318 | void pwm_free(struct pwm_device *pwm); | |
319 | int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state); | |
320 | int pwm_adjust_config(struct pwm_device *pwm); | |
321 | ||
322 | /** | |
323 | * pwm_config() - change a PWM device configuration | |
324 | * @pwm: PWM device | |
325 | * @duty_ns: "on" time (in nanoseconds) | |
326 | * @period_ns: duration (in nanoseconds) of one cycle | |
327 | * | |
328 | * Returns: 0 on success or a negative error code on failure. | |
329 | */ | |
330 | static inline int pwm_config(struct pwm_device *pwm, int duty_ns, | |
331 | int period_ns) | |
332 | { | |
333 | struct pwm_state state; | |
334 | ||
335 | if (!pwm) | |
336 | return -EINVAL; | |
337 | ||
ef2bf499 BN |
338 | if (duty_ns < 0 || period_ns < 0) |
339 | return -EINVAL; | |
340 | ||
5ec803ed BB |
341 | pwm_get_state(pwm, &state); |
342 | if (state.duty_cycle == duty_ns && state.period == period_ns) | |
343 | return 0; | |
344 | ||
345 | state.duty_cycle = duty_ns; | |
346 | state.period = period_ns; | |
347 | return pwm_apply_state(pwm, &state); | |
348 | } | |
349 | ||
350 | /** | |
351 | * pwm_set_polarity() - configure the polarity of a PWM signal | |
352 | * @pwm: PWM device | |
353 | * @polarity: new polarity of the PWM signal | |
354 | * | |
355 | * Note that the polarity cannot be configured while the PWM device is | |
356 | * enabled. | |
357 | * | |
358 | * Returns: 0 on success or a negative error code on failure. | |
359 | */ | |
360 | static inline int pwm_set_polarity(struct pwm_device *pwm, | |
361 | enum pwm_polarity polarity) | |
362 | { | |
363 | struct pwm_state state; | |
364 | ||
365 | if (!pwm) | |
366 | return -EINVAL; | |
367 | ||
368 | pwm_get_state(pwm, &state); | |
369 | if (state.polarity == polarity) | |
370 | return 0; | |
371 | ||
372 | /* | |
373 | * Changing the polarity of a running PWM without adjusting the | |
374 | * dutycycle/period value is a bit risky (can introduce glitches). | |
375 | * Return -EBUSY in this case. | |
376 | * Note that this is allowed when using pwm_apply_state() because | |
377 | * the user specifies all the parameters. | |
378 | */ | |
379 | if (state.enabled) | |
380 | return -EBUSY; | |
381 | ||
382 | state.polarity = polarity; | |
383 | return pwm_apply_state(pwm, &state); | |
384 | } | |
385 | ||
386 | /** | |
387 | * pwm_enable() - start a PWM output toggling | |
388 | * @pwm: PWM device | |
389 | * | |
390 | * Returns: 0 on success or a negative error code on failure. | |
391 | */ | |
392 | static inline int pwm_enable(struct pwm_device *pwm) | |
393 | { | |
394 | struct pwm_state state; | |
395 | ||
396 | if (!pwm) | |
397 | return -EINVAL; | |
398 | ||
399 | pwm_get_state(pwm, &state); | |
400 | if (state.enabled) | |
401 | return 0; | |
402 | ||
403 | state.enabled = true; | |
404 | return pwm_apply_state(pwm, &state); | |
405 | } | |
406 | ||
407 | /** | |
408 | * pwm_disable() - stop a PWM output toggling | |
409 | * @pwm: PWM device | |
410 | */ | |
411 | static inline void pwm_disable(struct pwm_device *pwm) | |
412 | { | |
413 | struct pwm_state state; | |
414 | ||
415 | if (!pwm) | |
416 | return; | |
417 | ||
418 | pwm_get_state(pwm, &state); | |
419 | if (!state.enabled) | |
420 | return; | |
421 | ||
422 | state.enabled = false; | |
423 | pwm_apply_state(pwm, &state); | |
424 | } | |
425 | ||
5ec803ed | 426 | /* PWM provider APIs */ |
3a3d1a4e LJ |
427 | int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result, |
428 | unsigned long timeout); | |
f051c466 TR |
429 | int pwm_set_chip_data(struct pwm_device *pwm, void *data); |
430 | void *pwm_get_chip_data(struct pwm_device *pwm); | |
431 | ||
b6a00fae TK |
432 | int pwmchip_add_with_polarity(struct pwm_chip *chip, |
433 | enum pwm_polarity polarity); | |
0c2498f1 SH |
434 | int pwmchip_add(struct pwm_chip *chip); |
435 | int pwmchip_remove(struct pwm_chip *chip); | |
f051c466 TR |
436 | struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, |
437 | unsigned int index, | |
438 | const char *label); | |
8138d2dd | 439 | |
83af2402 PA |
440 | struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc, |
441 | const struct of_phandle_args *args); | |
442 | ||
d4c0c470 | 443 | struct pwm_device *pwm_get(struct device *dev, const char *con_id); |
8eb96127 | 444 | struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id); |
8138d2dd TR |
445 | void pwm_put(struct pwm_device *pwm); |
446 | ||
d4c0c470 | 447 | struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id); |
261a5edd PU |
448 | struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, |
449 | const char *con_id); | |
6354316d | 450 | void devm_pwm_put(struct device *dev, struct pwm_device *pwm); |
0bcf168b | 451 | #else |
5ec803ed BB |
452 | static inline struct pwm_device *pwm_request(int pwm_id, const char *label) |
453 | { | |
454 | return ERR_PTR(-ENODEV); | |
455 | } | |
456 | ||
457 | static inline void pwm_free(struct pwm_device *pwm) | |
458 | { | |
459 | } | |
460 | ||
461 | static inline int pwm_apply_state(struct pwm_device *pwm, | |
462 | const struct pwm_state *state) | |
463 | { | |
464 | return -ENOTSUPP; | |
465 | } | |
466 | ||
467 | static inline int pwm_adjust_config(struct pwm_device *pwm) | |
468 | { | |
469 | return -ENOTSUPP; | |
470 | } | |
471 | ||
472 | static inline int pwm_config(struct pwm_device *pwm, int duty_ns, | |
473 | int period_ns) | |
474 | { | |
475 | return -EINVAL; | |
476 | } | |
477 | ||
3a3d1a4e LJ |
478 | static inline int pwm_capture(struct pwm_device *pwm, |
479 | struct pwm_capture *result, | |
480 | unsigned long timeout) | |
481 | { | |
482 | return -EINVAL; | |
483 | } | |
484 | ||
5ec803ed BB |
485 | static inline int pwm_set_polarity(struct pwm_device *pwm, |
486 | enum pwm_polarity polarity) | |
487 | { | |
488 | return -ENOTSUPP; | |
489 | } | |
490 | ||
491 | static inline int pwm_enable(struct pwm_device *pwm) | |
492 | { | |
493 | return -EINVAL; | |
494 | } | |
495 | ||
496 | static inline void pwm_disable(struct pwm_device *pwm) | |
497 | { | |
498 | } | |
499 | ||
0bcf168b TB |
500 | static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data) |
501 | { | |
502 | return -EINVAL; | |
503 | } | |
504 | ||
505 | static inline void *pwm_get_chip_data(struct pwm_device *pwm) | |
506 | { | |
507 | return NULL; | |
508 | } | |
509 | ||
510 | static inline int pwmchip_add(struct pwm_chip *chip) | |
511 | { | |
512 | return -EINVAL; | |
513 | } | |
514 | ||
b6a00fae TK |
515 | static inline int pwmchip_add_inversed(struct pwm_chip *chip) |
516 | { | |
517 | return -EINVAL; | |
518 | } | |
519 | ||
0bcf168b TB |
520 | static inline int pwmchip_remove(struct pwm_chip *chip) |
521 | { | |
522 | return -EINVAL; | |
523 | } | |
524 | ||
525 | static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, | |
526 | unsigned int index, | |
527 | const char *label) | |
528 | { | |
529 | return ERR_PTR(-ENODEV); | |
530 | } | |
531 | ||
532 | static inline struct pwm_device *pwm_get(struct device *dev, | |
533 | const char *consumer) | |
534 | { | |
535 | return ERR_PTR(-ENODEV); | |
536 | } | |
537 | ||
8eb96127 PU |
538 | static inline struct pwm_device *of_pwm_get(struct device_node *np, |
539 | const char *con_id) | |
540 | { | |
541 | return ERR_PTR(-ENODEV); | |
542 | } | |
543 | ||
0bcf168b TB |
544 | static inline void pwm_put(struct pwm_device *pwm) |
545 | { | |
546 | } | |
547 | ||
548 | static inline struct pwm_device *devm_pwm_get(struct device *dev, | |
549 | const char *consumer) | |
550 | { | |
551 | return ERR_PTR(-ENODEV); | |
552 | } | |
553 | ||
261a5edd PU |
554 | static inline struct pwm_device *devm_of_pwm_get(struct device *dev, |
555 | struct device_node *np, | |
556 | const char *con_id) | |
557 | { | |
558 | return ERR_PTR(-ENODEV); | |
559 | } | |
560 | ||
0bcf168b TB |
561 | static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm) |
562 | { | |
563 | } | |
564 | #endif | |
6354316d | 565 | |
5ec803ed BB |
566 | static inline void pwm_apply_args(struct pwm_device *pwm) |
567 | { | |
33cdcee0 BB |
568 | struct pwm_state state = { }; |
569 | ||
5ec803ed BB |
570 | /* |
571 | * PWM users calling pwm_apply_args() expect to have a fresh config | |
572 | * where the polarity and period are set according to pwm_args info. | |
573 | * The problem is, polarity can only be changed when the PWM is | |
574 | * disabled. | |
575 | * | |
576 | * PWM drivers supporting hardware readout may declare the PWM device | |
577 | * as enabled, and prevent polarity setting, which changes from the | |
578 | * existing behavior, where all PWM devices are declared as disabled | |
579 | * at startup (even if they are actually enabled), thus authorizing | |
580 | * polarity setting. | |
581 | * | |
33cdcee0 BB |
582 | * To fulfill this requirement, we apply a new state which disables |
583 | * the PWM device and set the reference period and polarity config. | |
5ec803ed BB |
584 | * |
585 | * Note that PWM users requiring a smooth handover between the | |
586 | * bootloader and the kernel (like critical regulators controlled by | |
587 | * PWM devices) will have to switch to the atomic API and avoid calling | |
588 | * pwm_apply_args(). | |
589 | */ | |
33cdcee0 BB |
590 | |
591 | state.enabled = false; | |
592 | state.polarity = pwm->args.polarity; | |
593 | state.period = pwm->args.period; | |
594 | ||
595 | pwm_apply_state(pwm, &state); | |
5ec803ed BB |
596 | } |
597 | ||
8138d2dd TR |
598 | struct pwm_lookup { |
599 | struct list_head list; | |
600 | const char *provider; | |
601 | unsigned int index; | |
602 | const char *dev_id; | |
603 | const char *con_id; | |
3796ce1d AB |
604 | unsigned int period; |
605 | enum pwm_polarity polarity; | |
b526a314 | 606 | const char *module; /* optional, may be NULL */ |
8138d2dd TR |
607 | }; |
608 | ||
b526a314 HG |
609 | #define PWM_LOOKUP_WITH_MODULE(_provider, _index, _dev_id, _con_id, \ |
610 | _period, _polarity, _module) \ | |
611 | { \ | |
612 | .provider = _provider, \ | |
613 | .index = _index, \ | |
614 | .dev_id = _dev_id, \ | |
615 | .con_id = _con_id, \ | |
616 | .period = _period, \ | |
617 | .polarity = _polarity, \ | |
618 | .module = _module, \ | |
8138d2dd TR |
619 | } |
620 | ||
b526a314 HG |
621 | #define PWM_LOOKUP(_provider, _index, _dev_id, _con_id, _period, _polarity) \ |
622 | PWM_LOOKUP_WITH_MODULE(_provider, _index, _dev_id, _con_id, _period, \ | |
623 | _polarity, NULL) | |
624 | ||
0bcf168b | 625 | #if IS_ENABLED(CONFIG_PWM) |
8138d2dd | 626 | void pwm_add_table(struct pwm_lookup *table, size_t num); |
efb0de55 | 627 | void pwm_remove_table(struct pwm_lookup *table, size_t num); |
0bcf168b TB |
628 | #else |
629 | static inline void pwm_add_table(struct pwm_lookup *table, size_t num) | |
630 | { | |
631 | } | |
efb0de55 SK |
632 | |
633 | static inline void pwm_remove_table(struct pwm_lookup *table, size_t num) | |
634 | { | |
635 | } | |
0c2498f1 SH |
636 | #endif |
637 | ||
76abbdde HS |
638 | #ifdef CONFIG_PWM_SYSFS |
639 | void pwmchip_sysfs_export(struct pwm_chip *chip); | |
640 | void pwmchip_sysfs_unexport(struct pwm_chip *chip); | |
0733424c | 641 | void pwmchip_sysfs_unexport_children(struct pwm_chip *chip); |
76abbdde HS |
642 | #else |
643 | static inline void pwmchip_sysfs_export(struct pwm_chip *chip) | |
644 | { | |
645 | } | |
646 | ||
647 | static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip) | |
648 | { | |
649 | } | |
0733424c DH |
650 | |
651 | static inline void pwmchip_sysfs_unexport_children(struct pwm_chip *chip) | |
652 | { | |
653 | } | |
76abbdde HS |
654 | #endif /* CONFIG_PWM_SYSFS */ |
655 | ||
5243ef8b | 656 | #endif /* __LINUX_PWM_H */ |