1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * pwm-fan.c - Hwmon driver for fans connected to PWM lines.
4 *
5 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
6 *
7 * Author: Kamil Debski <k.debski@samsung.com>
8 */
9
10 #include <linux/delay.h>
11 #include <linux/hwmon.h>
12 #include <linux/interrupt.h>
13 #include <linux/mod_devicetable.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/platform_device.h>
17 #include <linux/property.h>
18 #include <linux/pwm.h>
19 #include <linux/regulator/consumer.h>
20 #include <linux/sysfs.h>
21 #include <linux/thermal.h>
22 #include <linux/timer.h>
23
24 #define MAX_PWM 255
25
26 struct pwm_fan_tach {
27 int irq;
28 atomic_t pulses;
29 unsigned int rpm;
30 };
31
32 enum pwm_fan_enable_mode {
33 pwm_off_reg_off,
34 pwm_disable_reg_enable,
35 pwm_enable_reg_enable,
36 pwm_disable_reg_disable,
37 };
38
39 struct pwm_fan_ctx {
40 struct device *dev;
41
42 struct mutex lock;
43 struct pwm_device *pwm;
44 struct pwm_state pwm_state;
45 struct regulator *reg_en;
46 enum pwm_fan_enable_mode enable_mode;
47 bool regulator_enabled;
48 bool enabled;
49
50 int tach_count;
51 struct pwm_fan_tach *tachs;
52 u32 *pulses_per_revolution;
53 ktime_t sample_start;
54 struct timer_list rpm_timer;
55
56 unsigned int pwm_value;
57 unsigned int pwm_fan_state;
58 unsigned int pwm_fan_max_state;
59 unsigned int *pwm_fan_cooling_levels;
60 struct thermal_cooling_device *cdev;
61
62 struct hwmon_chip_info info;
63 struct hwmon_channel_info fan_channel;
64
65 u64 pwm_duty_cycle_from_stopped;
66 u32 pwm_usec_from_stopped;
67 };
68
69 /* This handler assumes self resetting edge triggered interrupt. */
pulse_handler(int irq,void * dev_id)70 static irqreturn_t pulse_handler(int irq, void *dev_id)
71 {
72 struct pwm_fan_tach *tach = dev_id;
73
74 atomic_inc(&tach->pulses);
75
76 return IRQ_HANDLED;
77 }
78
sample_timer(struct timer_list * t)79 static void sample_timer(struct timer_list *t)
80 {
81 struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer);
82 unsigned int delta = ktime_ms_delta(ktime_get(), ctx->sample_start);
83 int i;
84
85 if (delta) {
86 for (i = 0; i < ctx->tach_count; i++) {
87 struct pwm_fan_tach *tach = &ctx->tachs[i];
88 int pulses;
89
90 pulses = atomic_read(&tach->pulses);
91 atomic_sub(pulses, &tach->pulses);
92 tach->rpm = (unsigned int)(pulses * 1000 * 60) /
93 (ctx->pulses_per_revolution[i] * delta);
94 }
95
96 ctx->sample_start = ktime_get();
97 }
98
99 mod_timer(&ctx->rpm_timer, jiffies + HZ);
100 }
101
pwm_fan_enable_mode_2_state(int enable_mode,struct pwm_state * state,bool * enable_regulator)102 static void pwm_fan_enable_mode_2_state(int enable_mode,
103 struct pwm_state *state,
104 bool *enable_regulator)
105 {
106 switch (enable_mode) {
107 case pwm_disable_reg_enable:
108 /* disable pwm, keep regulator enabled */
109 state->enabled = false;
110 *enable_regulator = true;
111 break;
112 case pwm_enable_reg_enable:
113 /* keep pwm and regulator enabled */
114 state->enabled = true;
115 *enable_regulator = true;
116 break;
117 case pwm_off_reg_off:
118 case pwm_disable_reg_disable:
119 /* disable pwm and regulator */
120 state->enabled = false;
121 *enable_regulator = false;
122 }
123 }
124
pwm_fan_switch_power(struct pwm_fan_ctx * ctx,bool on)125 static int pwm_fan_switch_power(struct pwm_fan_ctx *ctx, bool on)
126 {
127 int ret = 0;
128
129 if (!ctx->reg_en)
130 return ret;
131
132 if (!ctx->regulator_enabled && on) {
133 ret = regulator_enable(ctx->reg_en);
134 if (ret == 0)
135 ctx->regulator_enabled = true;
136 } else if (ctx->regulator_enabled && !on) {
137 ret = regulator_disable(ctx->reg_en);
138 if (ret == 0)
139 ctx->regulator_enabled = false;
140 }
141 return ret;
142 }
143
pwm_fan_power_on(struct pwm_fan_ctx * ctx)144 static int pwm_fan_power_on(struct pwm_fan_ctx *ctx)
145 {
146 struct pwm_state *state = &ctx->pwm_state;
147 int ret;
148
149 if (ctx->enabled)
150 return 0;
151
152 ret = pwm_fan_switch_power(ctx, true);
153 if (ret < 0) {
154 dev_err(ctx->dev, "failed to enable power supply\n");
155 return ret;
156 }
157
158 state->enabled = true;
159 ret = pwm_apply_might_sleep(ctx->pwm, state);
160 if (ret) {
161 dev_err(ctx->dev, "failed to enable PWM\n");
162 goto disable_regulator;
163 }
164
165 ctx->enabled = true;
166
167 return 0;
168
169 disable_regulator:
170 pwm_fan_switch_power(ctx, false);
171 return ret;
172 }
173
pwm_fan_power_off(struct pwm_fan_ctx * ctx,bool force_disable)174 static int pwm_fan_power_off(struct pwm_fan_ctx *ctx, bool force_disable)
175 {
176 struct pwm_state *state = &ctx->pwm_state;
177 bool enable_regulator = false;
178 int ret;
179
180 if (!ctx->enabled)
181 return 0;
182
183 pwm_fan_enable_mode_2_state(ctx->enable_mode,
184 state,
185 &enable_regulator);
186
187 if (force_disable)
188 state->enabled = false;
189 state->duty_cycle = 0;
190 ret = pwm_apply_might_sleep(ctx->pwm, state);
191 if (ret) {
192 dev_err(ctx->dev, "failed to disable PWM\n");
193 return ret;
194 }
195
196 pwm_fan_switch_power(ctx, enable_regulator);
197
198 ctx->enabled = false;
199
200 return 0;
201 }
202
__set_pwm(struct pwm_fan_ctx * ctx,unsigned long pwm)203 static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
204 {
205 struct pwm_state *state = &ctx->pwm_state;
206 unsigned long final_pwm = pwm;
207 unsigned long period;
208 bool update = false;
209 int ret = 0;
210
211 if (pwm > 0) {
212 if (ctx->enable_mode == pwm_off_reg_off)
213 /* pwm-fan hard disabled */
214 return 0;
215
216 period = state->period;
217 update = state->duty_cycle < ctx->pwm_duty_cycle_from_stopped;
218 if (update)
219 state->duty_cycle = ctx->pwm_duty_cycle_from_stopped;
220 else
221 state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
222 ret = pwm_apply_might_sleep(ctx->pwm, state);
223 if (ret)
224 return ret;
225 ret = pwm_fan_power_on(ctx);
226 if (!ret && update) {
227 pwm = final_pwm;
228 state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
229 usleep_range(ctx->pwm_usec_from_stopped,
230 ctx->pwm_usec_from_stopped * 2);
231 ret = pwm_apply_might_sleep(ctx->pwm, state);
232 }
233 } else {
234 ret = pwm_fan_power_off(ctx, false);
235 }
236 if (!ret)
237 ctx->pwm_value = pwm;
238
239 return ret;
240 }
241
set_pwm(struct pwm_fan_ctx * ctx,unsigned long pwm)242 static int set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
243 {
244 int ret;
245
246 mutex_lock(&ctx->lock);
247 ret = __set_pwm(ctx, pwm);
248 mutex_unlock(&ctx->lock);
249
250 return ret;
251 }
252
pwm_fan_update_state(struct pwm_fan_ctx * ctx,unsigned long pwm)253 static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
254 {
255 int i;
256
257 for (i = 0; i < ctx->pwm_fan_max_state; ++i)
258 if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
259 break;
260
261 ctx->pwm_fan_state = i;
262 }
263
pwm_fan_update_enable(struct pwm_fan_ctx * ctx,long val)264 static int pwm_fan_update_enable(struct pwm_fan_ctx *ctx, long val)
265 {
266 int ret = 0;
267 int old_val;
268
269 mutex_lock(&ctx->lock);
270
271 if (ctx->enable_mode == val)
272 goto out;
273
274 old_val = ctx->enable_mode;
275 ctx->enable_mode = val;
276
277 if (val == 0) {
278 /* Disable pwm-fan unconditionally */
279 if (ctx->enabled)
280 ret = __set_pwm(ctx, 0);
281 else
282 ret = pwm_fan_switch_power(ctx, false);
283 if (ret)
284 ctx->enable_mode = old_val;
285 pwm_fan_update_state(ctx, 0);
286 } else {
287 /*
288 * Change PWM and/or regulator state if currently disabled
289 * Nothing to do if currently enabled
290 */
291 if (!ctx->enabled) {
292 struct pwm_state *state = &ctx->pwm_state;
293 bool enable_regulator = false;
294
295 state->duty_cycle = 0;
296 pwm_fan_enable_mode_2_state(val,
297 state,
298 &enable_regulator);
299
300 pwm_apply_might_sleep(ctx->pwm, state);
301 pwm_fan_switch_power(ctx, enable_regulator);
302 pwm_fan_update_state(ctx, 0);
303 }
304 }
305 out:
306 mutex_unlock(&ctx->lock);
307
308 return ret;
309 }
310
pwm_fan_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)311 static int pwm_fan_write(struct device *dev, enum hwmon_sensor_types type,
312 u32 attr, int channel, long val)
313 {
314 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
315 int ret;
316
317 switch (attr) {
318 case hwmon_pwm_input:
319 if (val < 0 || val > MAX_PWM)
320 return -EINVAL;
321 ret = set_pwm(ctx, val);
322 if (ret)
323 return ret;
324 pwm_fan_update_state(ctx, val);
325 break;
326 case hwmon_pwm_enable:
327 if (val < 0 || val > 3)
328 ret = -EINVAL;
329 else
330 ret = pwm_fan_update_enable(ctx, val);
331
332 return ret;
333 default:
334 return -EOPNOTSUPP;
335 }
336
337 return 0;
338 }
339
pwm_fan_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)340 static int pwm_fan_read(struct device *dev, enum hwmon_sensor_types type,
341 u32 attr, int channel, long *val)
342 {
343 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
344
345 switch (type) {
346 case hwmon_pwm:
347 switch (attr) {
348 case hwmon_pwm_input:
349 *val = ctx->pwm_value;
350 return 0;
351 case hwmon_pwm_enable:
352 *val = ctx->enable_mode;
353 return 0;
354 }
355 return -EOPNOTSUPP;
356 case hwmon_fan:
357 *val = ctx->tachs[channel].rpm;
358 return 0;
359
360 default:
361 return -ENOTSUPP;
362 }
363 }
364
pwm_fan_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)365 static umode_t pwm_fan_is_visible(const void *data,
366 enum hwmon_sensor_types type,
367 u32 attr, int channel)
368 {
369 switch (type) {
370 case hwmon_pwm:
371 return 0644;
372
373 case hwmon_fan:
374 return 0444;
375
376 default:
377 return 0;
378 }
379 }
380
381 static const struct hwmon_ops pwm_fan_hwmon_ops = {
382 .is_visible = pwm_fan_is_visible,
383 .read = pwm_fan_read,
384 .write = pwm_fan_write,
385 };
386
387 /* thermal cooling device callbacks */
pwm_fan_get_max_state(struct thermal_cooling_device * cdev,unsigned long * state)388 static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
389 unsigned long *state)
390 {
391 struct pwm_fan_ctx *ctx = cdev->devdata;
392
393 if (!ctx)
394 return -EINVAL;
395
396 *state = ctx->pwm_fan_max_state;
397
398 return 0;
399 }
400
pwm_fan_get_cur_state(struct thermal_cooling_device * cdev,unsigned long * state)401 static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
402 unsigned long *state)
403 {
404 struct pwm_fan_ctx *ctx = cdev->devdata;
405
406 if (!ctx)
407 return -EINVAL;
408
409 *state = ctx->pwm_fan_state;
410
411 return 0;
412 }
413
414 static int
pwm_fan_set_cur_state(struct thermal_cooling_device * cdev,unsigned long state)415 pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
416 {
417 struct pwm_fan_ctx *ctx = cdev->devdata;
418 int ret;
419
420 if (!ctx || (state > ctx->pwm_fan_max_state))
421 return -EINVAL;
422
423 if (state == ctx->pwm_fan_state)
424 return 0;
425
426 ret = set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
427 if (ret) {
428 dev_err(&cdev->device, "Cannot set pwm!\n");
429 return ret;
430 }
431
432 ctx->pwm_fan_state = state;
433
434 return ret;
435 }
436
437 static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
438 .get_max_state = pwm_fan_get_max_state,
439 .get_cur_state = pwm_fan_get_cur_state,
440 .set_cur_state = pwm_fan_set_cur_state,
441 };
442
pwm_fan_get_cooling_data(struct device * dev,struct pwm_fan_ctx * ctx)443 static int pwm_fan_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx)
444 {
445 int num, i, ret;
446
447 if (!device_property_present(dev, "cooling-levels"))
448 return 0;
449
450 ret = device_property_count_u32(dev, "cooling-levels");
451 if (ret <= 0) {
452 dev_err(dev, "Wrong data!\n");
453 return ret ? : -EINVAL;
454 }
455
456 num = ret;
457 ctx->pwm_fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),
458 GFP_KERNEL);
459 if (!ctx->pwm_fan_cooling_levels)
460 return -ENOMEM;
461
462 ret = device_property_read_u32_array(dev, "cooling-levels",
463 ctx->pwm_fan_cooling_levels, num);
464 if (ret) {
465 dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
466 return ret;
467 }
468
469 for (i = 0; i < num; i++) {
470 if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
471 dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
472 ctx->pwm_fan_cooling_levels[i], MAX_PWM);
473 return -EINVAL;
474 }
475 }
476
477 ctx->pwm_fan_max_state = num - 1;
478
479 return 0;
480 }
481
pwm_fan_cleanup(void * __ctx)482 static void pwm_fan_cleanup(void *__ctx)
483 {
484 struct pwm_fan_ctx *ctx = __ctx;
485
486 timer_delete_sync(&ctx->rpm_timer);
487 /* Switch off everything */
488 ctx->enable_mode = pwm_disable_reg_disable;
489 pwm_fan_power_off(ctx, true);
490 }
491
pwm_fan_probe(struct platform_device * pdev)492 static int pwm_fan_probe(struct platform_device *pdev)
493 {
494 struct thermal_cooling_device *cdev;
495 struct device *dev = &pdev->dev;
496 struct pwm_fan_ctx *ctx;
497 struct device *hwmon;
498 int ret;
499 const struct hwmon_channel_info **channels;
500 u32 initial_pwm, pwm_min_from_stopped = 0;
501 u32 *fan_channel_config;
502 int channel_count = 1; /* We always have a PWM channel. */
503 int i;
504
505 ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
506 if (!ctx)
507 return -ENOMEM;
508
509 mutex_init(&ctx->lock);
510
511 ctx->dev = &pdev->dev;
512 ctx->pwm = devm_pwm_get(dev, NULL);
513 if (IS_ERR(ctx->pwm))
514 return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");
515
516 platform_set_drvdata(pdev, ctx);
517
518 ctx->reg_en = devm_regulator_get_optional(dev, "fan");
519 if (IS_ERR(ctx->reg_en)) {
520 if (PTR_ERR(ctx->reg_en) != -ENODEV)
521 return PTR_ERR(ctx->reg_en);
522
523 ctx->reg_en = NULL;
524 }
525
526 pwm_init_state(ctx->pwm, &ctx->pwm_state);
527
528 /*
529 * PWM fans are controlled solely by the duty cycle of the PWM signal,
530 * they do not care about the exact timing. Thus set usage_power to true
531 * to allow less flexible hardware to work as a PWM source for fan
532 * control.
533 */
534 ctx->pwm_state.usage_power = true;
535
536 /*
537 * set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned
538 * long. Check this here to prevent the fan running at a too low
539 * frequency.
540 */
541 if (ctx->pwm_state.period > ULONG_MAX / MAX_PWM + 1) {
542 dev_err(dev, "Configured period too big\n");
543 return -EINVAL;
544 }
545
546 ctx->enable_mode = pwm_disable_reg_enable;
547
548 ret = pwm_fan_get_cooling_data(dev, ctx);
549 if (ret)
550 return ret;
551
552 /* use maximum cooling level if provided */
553 if (ctx->pwm_fan_cooling_levels)
554 initial_pwm = ctx->pwm_fan_cooling_levels[ctx->pwm_fan_max_state];
555 else
556 initial_pwm = MAX_PWM;
557
558 /*
559 * Set duty cycle to maximum allowed and enable PWM output as well as
560 * the regulator. In case of error nothing is changed
561 */
562 ret = set_pwm(ctx, initial_pwm);
563 if (ret) {
564 dev_err(dev, "Failed to configure PWM: %d\n", ret);
565 return ret;
566 }
567 timer_setup(&ctx->rpm_timer, sample_timer, 0);
568 ret = devm_add_action_or_reset(dev, pwm_fan_cleanup, ctx);
569 if (ret)
570 return ret;
571
572 ctx->tach_count = platform_irq_count(pdev);
573 if (ctx->tach_count < 0)
574 return dev_err_probe(dev, ctx->tach_count,
575 "Could not get number of fan tachometer inputs\n");
576 dev_dbg(dev, "%d fan tachometer inputs\n", ctx->tach_count);
577
578 if (ctx->tach_count) {
579 channel_count++; /* We also have a FAN channel. */
580
581 ctx->tachs = devm_kcalloc(dev, ctx->tach_count,
582 sizeof(struct pwm_fan_tach),
583 GFP_KERNEL);
584 if (!ctx->tachs)
585 return -ENOMEM;
586
587 ctx->fan_channel.type = hwmon_fan;
588 fan_channel_config = devm_kcalloc(dev, ctx->tach_count + 1,
589 sizeof(u32), GFP_KERNEL);
590 if (!fan_channel_config)
591 return -ENOMEM;
592 ctx->fan_channel.config = fan_channel_config;
593
594 ctx->pulses_per_revolution = devm_kmalloc_array(dev,
595 ctx->tach_count,
596 sizeof(*ctx->pulses_per_revolution),
597 GFP_KERNEL);
598 if (!ctx->pulses_per_revolution)
599 return -ENOMEM;
600
601 /* Setup default pulses per revolution */
602 for (i = 0; i < ctx->tach_count; i++)
603 ctx->pulses_per_revolution[i] = 2;
604
605 device_property_read_u32_array(dev, "pulses-per-revolution",
606 ctx->pulses_per_revolution, ctx->tach_count);
607 }
608
609 channels = devm_kcalloc(dev, channel_count + 1,
610 sizeof(struct hwmon_channel_info *), GFP_KERNEL);
611 if (!channels)
612 return -ENOMEM;
613
614 channels[0] = HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_ENABLE);
615
616 for (i = 0; i < ctx->tach_count; i++) {
617 struct pwm_fan_tach *tach = &ctx->tachs[i];
618
619 tach->irq = platform_get_irq(pdev, i);
620 if (tach->irq == -EPROBE_DEFER)
621 return tach->irq;
622 if (tach->irq > 0) {
623 ret = devm_request_irq(dev, tach->irq, pulse_handler, 0,
624 pdev->name, tach);
625 if (ret) {
626 dev_err(dev,
627 "Failed to request interrupt: %d\n",
628 ret);
629 return ret;
630 }
631 }
632
633 if (!ctx->pulses_per_revolution[i]) {
634 dev_err(dev, "pulses-per-revolution can't be zero.\n");
635 return -EINVAL;
636 }
637
638 fan_channel_config[i] = HWMON_F_INPUT;
639
640 dev_dbg(dev, "tach%d: irq=%d, pulses_per_revolution=%d\n",
641 i, tach->irq, ctx->pulses_per_revolution[i]);
642 }
643
644 if (ctx->tach_count > 0) {
645 ctx->sample_start = ktime_get();
646 mod_timer(&ctx->rpm_timer, jiffies + HZ);
647
648 channels[1] = &ctx->fan_channel;
649 }
650
651 ret = device_property_read_u32(dev, "fan-stop-to-start-percent",
652 &pwm_min_from_stopped);
653 if (!ret && pwm_min_from_stopped) {
654 ctx->pwm_duty_cycle_from_stopped =
655 DIV_ROUND_UP_ULL(pwm_min_from_stopped *
656 (ctx->pwm_state.period - 1),
657 100);
658 }
659 ret = device_property_read_u32(dev, "fan-stop-to-start-us",
660 &ctx->pwm_usec_from_stopped);
661 if (ret)
662 ctx->pwm_usec_from_stopped = 250000;
663
664 ctx->info.ops = &pwm_fan_hwmon_ops;
665 ctx->info.info = channels;
666
667 hwmon = devm_hwmon_device_register_with_info(dev, "pwmfan",
668 ctx, &ctx->info, NULL);
669 if (IS_ERR(hwmon)) {
670 dev_err(dev, "Failed to register hwmon device\n");
671 return PTR_ERR(hwmon);
672 }
673
674 ctx->pwm_fan_state = ctx->pwm_fan_max_state;
675 if (IS_ENABLED(CONFIG_THERMAL)) {
676 cdev = devm_thermal_of_cooling_device_register(dev,
677 dev->of_node, "pwm-fan", ctx, &pwm_fan_cooling_ops);
678 if (IS_ERR(cdev)) {
679 ret = PTR_ERR(cdev);
680 dev_err(dev,
681 "Failed to register pwm-fan as cooling device: %d\n",
682 ret);
683 return ret;
684 }
685 ctx->cdev = cdev;
686 }
687
688 return 0;
689 }
690
pwm_fan_shutdown(struct platform_device * pdev)691 static void pwm_fan_shutdown(struct platform_device *pdev)
692 {
693 struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
694
695 pwm_fan_cleanup(ctx);
696 }
697
pwm_fan_suspend(struct device * dev)698 static int pwm_fan_suspend(struct device *dev)
699 {
700 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
701
702 return pwm_fan_power_off(ctx, true);
703 }
704
pwm_fan_resume(struct device * dev)705 static int pwm_fan_resume(struct device *dev)
706 {
707 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
708
709 return set_pwm(ctx, ctx->pwm_value);
710 }
711
712 static DEFINE_SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
713
714 static const struct of_device_id of_pwm_fan_match[] = {
715 { .compatible = "pwm-fan", },
716 {},
717 };
718 MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
719
720 static struct platform_driver pwm_fan_driver = {
721 .probe = pwm_fan_probe,
722 .shutdown = pwm_fan_shutdown,
723 .driver = {
724 .name = "pwm-fan",
725 .pm = pm_sleep_ptr(&pwm_fan_pm),
726 .of_match_table = of_pwm_fan_match,
727 },
728 };
729
730 module_platform_driver(pwm_fan_driver);
731
732 MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
733 MODULE_ALIAS("platform:pwm-fan");
734 MODULE_DESCRIPTION("PWM FAN driver");
735 MODULE_LICENSE("GPL");
736