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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/hwmon.h>
11#include <linux/hwmon-sysfs.h>
12#include <linux/interrupt.h>
13#include <linux/module.h>
14#include <linux/mutex.h>
15#include <linux/of.h>
16#include <linux/platform_device.h>
17#include <linux/pwm.h>
18#include <linux/regulator/consumer.h>
19#include <linux/sysfs.h>
20#include <linux/thermal.h>
21#include <linux/timer.h>
22
23#define MAX_PWM 255
24
25struct pwm_fan_ctx {
26 struct mutex lock;
27 struct pwm_device *pwm;
28 struct regulator *reg_en;
29
30 int irq;
31 atomic_t pulses;
32 unsigned int rpm;
33 u8 pulses_per_revolution;
34 ktime_t sample_start;
35 struct timer_list rpm_timer;
36
37 unsigned int pwm_value;
38 unsigned int pwm_fan_state;
39 unsigned int pwm_fan_max_state;
40 unsigned int *pwm_fan_cooling_levels;
41 struct thermal_cooling_device *cdev;
42};
43
44/* This handler assumes self resetting edge triggered interrupt. */
45static irqreturn_t pulse_handler(int irq, void *dev_id)
46{
47 struct pwm_fan_ctx *ctx = dev_id;
48
49 atomic_inc(&ctx->pulses);
50
51 return IRQ_HANDLED;
52}
53
54static void sample_timer(struct timer_list *t)
55{
56 struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer);
57 int pulses;
58 u64 tmp;
59
60 pulses = atomic_read(&ctx->pulses);
61 atomic_sub(pulses, &ctx->pulses);
62 tmp = (u64)pulses * ktime_ms_delta(ktime_get(), ctx->sample_start) * 60;
63 do_div(tmp, ctx->pulses_per_revolution * 1000);
64 ctx->rpm = tmp;
65
66 ctx->sample_start = ktime_get();
67 mod_timer(&ctx->rpm_timer, jiffies + HZ);
68}
69
70static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
71{
72 unsigned long period;
73 int ret = 0;
74 struct pwm_state state = { };
75
76 mutex_lock(&ctx->lock);
77 if (ctx->pwm_value == pwm)
78 goto exit_set_pwm_err;
79
80 pwm_init_state(ctx->pwm, &state);
81 period = ctx->pwm->args.period;
82 state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
83 state.enabled = pwm ? true : false;
84
85 ret = pwm_apply_state(ctx->pwm, &state);
86 if (!ret)
87 ctx->pwm_value = pwm;
88exit_set_pwm_err:
89 mutex_unlock(&ctx->lock);
90 return ret;
91}
92
93static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
94{
95 int i;
96
97 for (i = 0; i < ctx->pwm_fan_max_state; ++i)
98 if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
99 break;
100
101 ctx->pwm_fan_state = i;
102}
103
104static ssize_t pwm_store(struct device *dev, struct device_attribute *attr,
105 const char *buf, size_t count)
106{
107 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
108 unsigned long pwm;
109 int ret;
110
111 if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM)
112 return -EINVAL;
113
114 ret = __set_pwm(ctx, pwm);
115 if (ret)
116 return ret;
117
118 pwm_fan_update_state(ctx, pwm);
119 return count;
120}
121
122static ssize_t pwm_show(struct device *dev, struct device_attribute *attr,
123 char *buf)
124{
125 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
126
127 return sprintf(buf, "%u\n", ctx->pwm_value);
128}
129
130static ssize_t rpm_show(struct device *dev,
131 struct device_attribute *attr, char *buf)
132{
133 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
134
135 return sprintf(buf, "%u\n", ctx->rpm);
136}
137
138static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
139static SENSOR_DEVICE_ATTR_RO(fan1_input, rpm, 0);
140
141static struct attribute *pwm_fan_attrs[] = {
142 &sensor_dev_attr_pwm1.dev_attr.attr,
143 &sensor_dev_attr_fan1_input.dev_attr.attr,
144 NULL,
145};
146
147static umode_t pwm_fan_attrs_visible(struct kobject *kobj, struct attribute *a,
148 int n)
149{
150 struct device *dev = container_of(kobj, struct device, kobj);
151 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
152
153 /* Hide fan_input in case no interrupt is available */
154 if (n == 1 && ctx->irq <= 0)
155 return 0;
156
157 return a->mode;
158}
159
160static const struct attribute_group pwm_fan_group = {
161 .attrs = pwm_fan_attrs,
162 .is_visible = pwm_fan_attrs_visible,
163};
164
165static const struct attribute_group *pwm_fan_groups[] = {
166 &pwm_fan_group,
167 NULL,
168};
169
170/* thermal cooling device callbacks */
171static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
172 unsigned long *state)
173{
174 struct pwm_fan_ctx *ctx = cdev->devdata;
175
176 if (!ctx)
177 return -EINVAL;
178
179 *state = ctx->pwm_fan_max_state;
180
181 return 0;
182}
183
184static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
185 unsigned long *state)
186{
187 struct pwm_fan_ctx *ctx = cdev->devdata;
188
189 if (!ctx)
190 return -EINVAL;
191
192 *state = ctx->pwm_fan_state;
193
194 return 0;
195}
196
197static int
198pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
199{
200 struct pwm_fan_ctx *ctx = cdev->devdata;
201 int ret;
202
203 if (!ctx || (state > ctx->pwm_fan_max_state))
204 return -EINVAL;
205
206 if (state == ctx->pwm_fan_state)
207 return 0;
208
209 ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
210 if (ret) {
211 dev_err(&cdev->device, "Cannot set pwm!\n");
212 return ret;
213 }
214
215 ctx->pwm_fan_state = state;
216
217 return ret;
218}
219
220static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
221 .get_max_state = pwm_fan_get_max_state,
222 .get_cur_state = pwm_fan_get_cur_state,
223 .set_cur_state = pwm_fan_set_cur_state,
224};
225
226static int pwm_fan_of_get_cooling_data(struct device *dev,
227 struct pwm_fan_ctx *ctx)
228{
229 struct device_node *np = dev->of_node;
230 int num, i, ret;
231
232 if (!of_find_property(np, "cooling-levels", NULL))
233 return 0;
234
235 ret = of_property_count_u32_elems(np, "cooling-levels");
236 if (ret <= 0) {
237 dev_err(dev, "Wrong data!\n");
238 return ret ? : -EINVAL;
239 }
240
241 num = ret;
242 ctx->pwm_fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),
243 GFP_KERNEL);
244 if (!ctx->pwm_fan_cooling_levels)
245 return -ENOMEM;
246
247 ret = of_property_read_u32_array(np, "cooling-levels",
248 ctx->pwm_fan_cooling_levels, num);
249 if (ret) {
250 dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
251 return ret;
252 }
253
254 for (i = 0; i < num; i++) {
255 if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
256 dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
257 ctx->pwm_fan_cooling_levels[i], MAX_PWM);
258 return -EINVAL;
259 }
260 }
261
262 ctx->pwm_fan_max_state = num - 1;
263
264 return 0;
265}
266
267static void pwm_fan_regulator_disable(void *data)
268{
269 regulator_disable(data);
270}
271
272static void pwm_fan_pwm_disable(void *__ctx)
273{
274 struct pwm_fan_ctx *ctx = __ctx;
275 pwm_disable(ctx->pwm);
276 del_timer_sync(&ctx->rpm_timer);
277}
278
279static int pwm_fan_probe(struct platform_device *pdev)
280{
281 struct thermal_cooling_device *cdev;
282 struct device *dev = &pdev->dev;
283 struct pwm_fan_ctx *ctx;
284 struct device *hwmon;
285 int ret;
286 struct pwm_state state = { };
287 u32 ppr = 2;
288
289 ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
290 if (!ctx)
291 return -ENOMEM;
292
293 mutex_init(&ctx->lock);
294
295 ctx->pwm = devm_of_pwm_get(dev, dev->of_node, NULL);
296 if (IS_ERR(ctx->pwm)) {
297 ret = PTR_ERR(ctx->pwm);
298
299 if (ret != -EPROBE_DEFER)
300 dev_err(dev, "Could not get PWM: %d\n", ret);
301
302 return ret;
303 }
304
305 platform_set_drvdata(pdev, ctx);
306
307 ctx->irq = platform_get_irq_optional(pdev, 0);
308 if (ctx->irq == -EPROBE_DEFER)
309 return ctx->irq;
310
311 ctx->reg_en = devm_regulator_get_optional(dev, "fan");
312 if (IS_ERR(ctx->reg_en)) {
313 if (PTR_ERR(ctx->reg_en) != -ENODEV)
314 return PTR_ERR(ctx->reg_en);
315
316 ctx->reg_en = NULL;
317 } else {
318 ret = regulator_enable(ctx->reg_en);
319 if (ret) {
320 dev_err(dev, "Failed to enable fan supply: %d\n", ret);
321 return ret;
322 }
323 ret = devm_add_action_or_reset(dev, pwm_fan_regulator_disable,
324 ctx->reg_en);
325 if (ret)
326 return ret;
327 }
328
329 ctx->pwm_value = MAX_PWM;
330
331 /* Set duty cycle to maximum allowed and enable PWM output */
332 pwm_init_state(ctx->pwm, &state);
333 state.duty_cycle = ctx->pwm->args.period - 1;
334 state.enabled = true;
335
336 ret = pwm_apply_state(ctx->pwm, &state);
337 if (ret) {
338 dev_err(dev, "Failed to configure PWM: %d\n", ret);
339 return ret;
340 }
341 timer_setup(&ctx->rpm_timer, sample_timer, 0);
342 ret = devm_add_action_or_reset(dev, pwm_fan_pwm_disable, ctx);
343 if (ret)
344 return ret;
345
346 of_property_read_u32(dev->of_node, "pulses-per-revolution", &ppr);
347 ctx->pulses_per_revolution = ppr;
348 if (!ctx->pulses_per_revolution) {
349 dev_err(dev, "pulses-per-revolution can't be zero.\n");
350 return -EINVAL;
351 }
352
353 if (ctx->irq > 0) {
354 ret = devm_request_irq(dev, ctx->irq, pulse_handler, 0,
355 pdev->name, ctx);
356 if (ret) {
357 dev_err(dev, "Failed to request interrupt: %d\n", ret);
358 return ret;
359 }
360 ctx->sample_start = ktime_get();
361 mod_timer(&ctx->rpm_timer, jiffies + HZ);
362 }
363
364 hwmon = devm_hwmon_device_register_with_groups(dev, "pwmfan",
365 ctx, pwm_fan_groups);
366 if (IS_ERR(hwmon)) {
367 dev_err(dev, "Failed to register hwmon device\n");
368 return PTR_ERR(hwmon);
369 }
370
371 ret = pwm_fan_of_get_cooling_data(dev, ctx);
372 if (ret)
373 return ret;
374
375 ctx->pwm_fan_state = ctx->pwm_fan_max_state;
376 if (IS_ENABLED(CONFIG_THERMAL)) {
377 cdev = devm_thermal_of_cooling_device_register(dev,
378 dev->of_node, "pwm-fan", ctx, &pwm_fan_cooling_ops);
379 if (IS_ERR(cdev)) {
380 ret = PTR_ERR(cdev);
381 dev_err(dev,
382 "Failed to register pwm-fan as cooling device: %d\n",
383 ret);
384 return ret;
385 }
386 ctx->cdev = cdev;
387 thermal_cdev_update(cdev);
388 }
389
390 return 0;
391}
392
393static int pwm_fan_disable(struct device *dev)
394{
395 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
396 struct pwm_args args;
397 int ret;
398
399 pwm_get_args(ctx->pwm, &args);
400
401 if (ctx->pwm_value) {
402 ret = pwm_config(ctx->pwm, 0, args.period);
403 if (ret < 0)
404 return ret;
405
406 pwm_disable(ctx->pwm);
407 }
408
409 if (ctx->reg_en) {
410 ret = regulator_disable(ctx->reg_en);
411 if (ret) {
412 dev_err(dev, "Failed to disable fan supply: %d\n", ret);
413 return ret;
414 }
415 }
416
417 return 0;
418}
419
420static void pwm_fan_shutdown(struct platform_device *pdev)
421{
422 pwm_fan_disable(&pdev->dev);
423}
424
425#ifdef CONFIG_PM_SLEEP
426static int pwm_fan_suspend(struct device *dev)
427{
428 return pwm_fan_disable(dev);
429}
430
431static int pwm_fan_resume(struct device *dev)
432{
433 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
434 struct pwm_args pargs;
435 unsigned long duty;
436 int ret;
437
438 if (ctx->reg_en) {
439 ret = regulator_enable(ctx->reg_en);
440 if (ret) {
441 dev_err(dev, "Failed to enable fan supply: %d\n", ret);
442 return ret;
443 }
444 }
445
446 if (ctx->pwm_value == 0)
447 return 0;
448
449 pwm_get_args(ctx->pwm, &pargs);
450 duty = DIV_ROUND_UP_ULL(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
451 ret = pwm_config(ctx->pwm, duty, pargs.period);
452 if (ret)
453 return ret;
454 return pwm_enable(ctx->pwm);
455}
456#endif
457
458static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
459
460static const struct of_device_id of_pwm_fan_match[] = {
461 { .compatible = "pwm-fan", },
462 {},
463};
464MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
465
466static struct platform_driver pwm_fan_driver = {
467 .probe = pwm_fan_probe,
468 .shutdown = pwm_fan_shutdown,
469 .driver = {
470 .name = "pwm-fan",
471 .pm = &pwm_fan_pm,
472 .of_match_table = of_pwm_fan_match,
473 },
474};
475
476module_platform_driver(pwm_fan_driver);
477
478MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
479MODULE_ALIAS("platform:pwm-fan");
480MODULE_DESCRIPTION("PWM FAN driver");
481MODULE_LICENSE("GPL");
1/*
2 * pwm-fan.c - Hwmon driver for fans connected to PWM lines.
3 *
4 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
5 *
6 * Author: Kamil Debski <k.debski@samsung.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 */
18
19#include <linux/hwmon.h>
20#include <linux/hwmon-sysfs.h>
21#include <linux/module.h>
22#include <linux/mutex.h>
23#include <linux/of.h>
24#include <linux/platform_device.h>
25#include <linux/pwm.h>
26#include <linux/sysfs.h>
27#include <linux/thermal.h>
28
29#define MAX_PWM 255
30
31struct pwm_fan_ctx {
32 struct mutex lock;
33 struct pwm_device *pwm;
34 unsigned int pwm_value;
35 unsigned int pwm_fan_state;
36 unsigned int pwm_fan_max_state;
37 unsigned int *pwm_fan_cooling_levels;
38 struct thermal_cooling_device *cdev;
39};
40
41static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
42{
43 unsigned long period;
44 int ret = 0;
45 struct pwm_state state = { };
46
47 mutex_lock(&ctx->lock);
48 if (ctx->pwm_value == pwm)
49 goto exit_set_pwm_err;
50
51 pwm_init_state(ctx->pwm, &state);
52 period = ctx->pwm->args.period;
53 state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
54 state.enabled = pwm ? true : false;
55
56 ret = pwm_apply_state(ctx->pwm, &state);
57 if (!ret)
58 ctx->pwm_value = pwm;
59exit_set_pwm_err:
60 mutex_unlock(&ctx->lock);
61 return ret;
62}
63
64static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
65{
66 int i;
67
68 for (i = 0; i < ctx->pwm_fan_max_state; ++i)
69 if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
70 break;
71
72 ctx->pwm_fan_state = i;
73}
74
75static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
76 const char *buf, size_t count)
77{
78 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
79 unsigned long pwm;
80 int ret;
81
82 if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM)
83 return -EINVAL;
84
85 ret = __set_pwm(ctx, pwm);
86 if (ret)
87 return ret;
88
89 pwm_fan_update_state(ctx, pwm);
90 return count;
91}
92
93static ssize_t show_pwm(struct device *dev,
94 struct device_attribute *attr, char *buf)
95{
96 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
97
98 return sprintf(buf, "%u\n", ctx->pwm_value);
99}
100
101
102static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm, 0);
103
104static struct attribute *pwm_fan_attrs[] = {
105 &sensor_dev_attr_pwm1.dev_attr.attr,
106 NULL,
107};
108
109ATTRIBUTE_GROUPS(pwm_fan);
110
111/* thermal cooling device callbacks */
112static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
113 unsigned long *state)
114{
115 struct pwm_fan_ctx *ctx = cdev->devdata;
116
117 if (!ctx)
118 return -EINVAL;
119
120 *state = ctx->pwm_fan_max_state;
121
122 return 0;
123}
124
125static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
126 unsigned long *state)
127{
128 struct pwm_fan_ctx *ctx = cdev->devdata;
129
130 if (!ctx)
131 return -EINVAL;
132
133 *state = ctx->pwm_fan_state;
134
135 return 0;
136}
137
138static int
139pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
140{
141 struct pwm_fan_ctx *ctx = cdev->devdata;
142 int ret;
143
144 if (!ctx || (state > ctx->pwm_fan_max_state))
145 return -EINVAL;
146
147 if (state == ctx->pwm_fan_state)
148 return 0;
149
150 ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
151 if (ret) {
152 dev_err(&cdev->device, "Cannot set pwm!\n");
153 return ret;
154 }
155
156 ctx->pwm_fan_state = state;
157
158 return ret;
159}
160
161static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
162 .get_max_state = pwm_fan_get_max_state,
163 .get_cur_state = pwm_fan_get_cur_state,
164 .set_cur_state = pwm_fan_set_cur_state,
165};
166
167static int pwm_fan_of_get_cooling_data(struct device *dev,
168 struct pwm_fan_ctx *ctx)
169{
170 struct device_node *np = dev->of_node;
171 int num, i, ret;
172
173 if (!of_find_property(np, "cooling-levels", NULL))
174 return 0;
175
176 ret = of_property_count_u32_elems(np, "cooling-levels");
177 if (ret <= 0) {
178 dev_err(dev, "Wrong data!\n");
179 return ret ? : -EINVAL;
180 }
181
182 num = ret;
183 ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32),
184 GFP_KERNEL);
185 if (!ctx->pwm_fan_cooling_levels)
186 return -ENOMEM;
187
188 ret = of_property_read_u32_array(np, "cooling-levels",
189 ctx->pwm_fan_cooling_levels, num);
190 if (ret) {
191 dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
192 return ret;
193 }
194
195 for (i = 0; i < num; i++) {
196 if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
197 dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
198 ctx->pwm_fan_cooling_levels[i], MAX_PWM);
199 return -EINVAL;
200 }
201 }
202
203 ctx->pwm_fan_max_state = num - 1;
204
205 return 0;
206}
207
208static int pwm_fan_probe(struct platform_device *pdev)
209{
210 struct thermal_cooling_device *cdev;
211 struct pwm_fan_ctx *ctx;
212 struct device *hwmon;
213 int ret;
214 struct pwm_state state = { };
215
216 ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
217 if (!ctx)
218 return -ENOMEM;
219
220 mutex_init(&ctx->lock);
221
222 ctx->pwm = devm_of_pwm_get(&pdev->dev, pdev->dev.of_node, NULL);
223 if (IS_ERR(ctx->pwm)) {
224 dev_err(&pdev->dev, "Could not get PWM\n");
225 return PTR_ERR(ctx->pwm);
226 }
227
228 platform_set_drvdata(pdev, ctx);
229
230 ctx->pwm_value = MAX_PWM;
231
232 /* Set duty cycle to maximum allowed and enable PWM output */
233 pwm_init_state(ctx->pwm, &state);
234 state.duty_cycle = ctx->pwm->args.period - 1;
235 state.enabled = true;
236
237 ret = pwm_apply_state(ctx->pwm, &state);
238 if (ret) {
239 dev_err(&pdev->dev, "Failed to configure PWM\n");
240 return ret;
241 }
242
243 hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
244 ctx, pwm_fan_groups);
245 if (IS_ERR(hwmon)) {
246 dev_err(&pdev->dev, "Failed to register hwmon device\n");
247 ret = PTR_ERR(hwmon);
248 goto err_pwm_disable;
249 }
250
251 ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx);
252 if (ret)
253 return ret;
254
255 ctx->pwm_fan_state = ctx->pwm_fan_max_state;
256 if (IS_ENABLED(CONFIG_THERMAL)) {
257 cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
258 "pwm-fan", ctx,
259 &pwm_fan_cooling_ops);
260 if (IS_ERR(cdev)) {
261 dev_err(&pdev->dev,
262 "Failed to register pwm-fan as cooling device");
263 ret = PTR_ERR(cdev);
264 goto err_pwm_disable;
265 }
266 ctx->cdev = cdev;
267 thermal_cdev_update(cdev);
268 }
269
270 return 0;
271
272err_pwm_disable:
273 state.enabled = false;
274 pwm_apply_state(ctx->pwm, &state);
275
276 return ret;
277}
278
279static int pwm_fan_remove(struct platform_device *pdev)
280{
281 struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
282
283 thermal_cooling_device_unregister(ctx->cdev);
284 if (ctx->pwm_value)
285 pwm_disable(ctx->pwm);
286 return 0;
287}
288
289#ifdef CONFIG_PM_SLEEP
290static int pwm_fan_suspend(struct device *dev)
291{
292 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
293
294 if (ctx->pwm_value)
295 pwm_disable(ctx->pwm);
296 return 0;
297}
298
299static int pwm_fan_resume(struct device *dev)
300{
301 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
302 struct pwm_args pargs;
303 unsigned long duty;
304 int ret;
305
306 if (ctx->pwm_value == 0)
307 return 0;
308
309 pwm_get_args(ctx->pwm, &pargs);
310 duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
311 ret = pwm_config(ctx->pwm, duty, pargs.period);
312 if (ret)
313 return ret;
314 return pwm_enable(ctx->pwm);
315}
316#endif
317
318static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
319
320static const struct of_device_id of_pwm_fan_match[] = {
321 { .compatible = "pwm-fan", },
322 {},
323};
324MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
325
326static struct platform_driver pwm_fan_driver = {
327 .probe = pwm_fan_probe,
328 .remove = pwm_fan_remove,
329 .driver = {
330 .name = "pwm-fan",
331 .pm = &pwm_fan_pm,
332 .of_match_table = of_pwm_fan_match,
333 },
334};
335
336module_platform_driver(pwm_fan_driver);
337
338MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
339MODULE_ALIAS("platform:pwm-fan");
340MODULE_DESCRIPTION("PWM FAN driver");
341MODULE_LICENSE("GPL");