Commit | Line | Data |
---|---|---|
d82d5776 KD |
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> | |
6b1ec478 | 21 | #include <linux/interrupt.h> |
d82d5776 KD |
22 | #include <linux/module.h> |
23 | #include <linux/mutex.h> | |
24 | #include <linux/of.h> | |
25 | #include <linux/platform_device.h> | |
26 | #include <linux/pwm.h> | |
b57e1d42 | 27 | #include <linux/regulator/consumer.h> |
d82d5776 | 28 | #include <linux/sysfs.h> |
b6bddec0 | 29 | #include <linux/thermal.h> |
6b1ec478 | 30 | #include <linux/timer.h> |
d82d5776 KD |
31 | |
32 | #define MAX_PWM 255 | |
33 | ||
34 | struct pwm_fan_ctx { | |
35 | struct mutex lock; | |
36 | struct pwm_device *pwm; | |
b57e1d42 | 37 | struct regulator *reg_en; |
6b1ec478 SW |
38 | |
39 | int irq; | |
40 | atomic_t pulses; | |
41 | unsigned int rpm; | |
42 | u8 pulses_per_revolution; | |
43 | ktime_t sample_start; | |
44 | struct timer_list rpm_timer; | |
45 | ||
2e5219c7 LM |
46 | unsigned int pwm_value; |
47 | unsigned int pwm_fan_state; | |
48 | unsigned int pwm_fan_max_state; | |
49 | unsigned int *pwm_fan_cooling_levels; | |
b6bddec0 | 50 | struct thermal_cooling_device *cdev; |
d82d5776 KD |
51 | }; |
52 | ||
6b1ec478 SW |
53 | /* This handler assumes self resetting edge triggered interrupt. */ |
54 | static irqreturn_t pulse_handler(int irq, void *dev_id) | |
55 | { | |
56 | struct pwm_fan_ctx *ctx = dev_id; | |
57 | ||
58 | atomic_inc(&ctx->pulses); | |
59 | ||
60 | return IRQ_HANDLED; | |
61 | } | |
62 | ||
63 | static void sample_timer(struct timer_list *t) | |
64 | { | |
65 | struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer); | |
66 | int pulses; | |
67 | u64 tmp; | |
68 | ||
69 | pulses = atomic_read(&ctx->pulses); | |
70 | atomic_sub(pulses, &ctx->pulses); | |
71 | tmp = (u64)pulses * ktime_ms_delta(ktime_get(), ctx->sample_start) * 60; | |
72 | do_div(tmp, ctx->pulses_per_revolution * 1000); | |
73 | ctx->rpm = tmp; | |
74 | ||
75 | ctx->sample_start = ktime_get(); | |
76 | mod_timer(&ctx->rpm_timer, jiffies + HZ); | |
77 | } | |
78 | ||
cb85ca33 | 79 | static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) |
d82d5776 | 80 | { |
677252a1 | 81 | unsigned long period; |
cb85ca33 | 82 | int ret = 0; |
677252a1 | 83 | struct pwm_state state = { }; |
2289711c | 84 | |
d82d5776 | 85 | mutex_lock(&ctx->lock); |
d82d5776 | 86 | if (ctx->pwm_value == pwm) |
cb85ca33 | 87 | goto exit_set_pwm_err; |
d82d5776 | 88 | |
677252a1 BZ |
89 | pwm_init_state(ctx->pwm, &state); |
90 | period = ctx->pwm->args.period; | |
91 | state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); | |
92 | state.enabled = pwm ? true : false; | |
f354169e | 93 | |
677252a1 BZ |
94 | ret = pwm_apply_state(ctx->pwm, &state); |
95 | if (!ret) | |
96 | ctx->pwm_value = pwm; | |
d82d5776 KD |
97 | exit_set_pwm_err: |
98 | mutex_unlock(&ctx->lock); | |
99 | return ret; | |
100 | } | |
101 | ||
b6bddec0 LM |
102 | static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm) |
103 | { | |
104 | int i; | |
105 | ||
106 | for (i = 0; i < ctx->pwm_fan_max_state; ++i) | |
107 | if (pwm < ctx->pwm_fan_cooling_levels[i + 1]) | |
108 | break; | |
109 | ||
110 | ctx->pwm_fan_state = i; | |
111 | } | |
112 | ||
cb1d8534 GR |
113 | static ssize_t pwm_store(struct device *dev, struct device_attribute *attr, |
114 | const char *buf, size_t count) | |
cb85ca33 LM |
115 | { |
116 | struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); | |
117 | unsigned long pwm; | |
118 | int ret; | |
119 | ||
120 | if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM) | |
121 | return -EINVAL; | |
122 | ||
123 | ret = __set_pwm(ctx, pwm); | |
124 | if (ret) | |
125 | return ret; | |
126 | ||
b6bddec0 | 127 | pwm_fan_update_state(ctx, pwm); |
cb85ca33 LM |
128 | return count; |
129 | } | |
130 | ||
cb1d8534 GR |
131 | static ssize_t pwm_show(struct device *dev, struct device_attribute *attr, |
132 | char *buf) | |
d82d5776 KD |
133 | { |
134 | struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); | |
135 | ||
136 | return sprintf(buf, "%u\n", ctx->pwm_value); | |
137 | } | |
138 | ||
6b1ec478 SW |
139 | static ssize_t rpm_show(struct device *dev, |
140 | struct device_attribute *attr, char *buf) | |
141 | { | |
142 | struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); | |
143 | ||
144 | return sprintf(buf, "%u\n", ctx->rpm); | |
145 | } | |
d82d5776 | 146 | |
cb1d8534 | 147 | static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0); |
6b1ec478 | 148 | static SENSOR_DEVICE_ATTR_RO(fan1_input, rpm, 0); |
d82d5776 KD |
149 | |
150 | static struct attribute *pwm_fan_attrs[] = { | |
151 | &sensor_dev_attr_pwm1.dev_attr.attr, | |
6b1ec478 | 152 | &sensor_dev_attr_fan1_input.dev_attr.attr, |
d82d5776 KD |
153 | NULL, |
154 | }; | |
155 | ||
6b1ec478 SW |
156 | static umode_t pwm_fan_attrs_visible(struct kobject *kobj, struct attribute *a, |
157 | int n) | |
158 | { | |
159 | struct device *dev = container_of(kobj, struct device, kobj); | |
160 | struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); | |
161 | ||
162 | /* Hide fan_input in case no interrupt is available */ | |
163 | if (n == 1 && ctx->irq <= 0) | |
164 | return 0; | |
165 | ||
166 | return a->mode; | |
167 | } | |
168 | ||
169 | static const struct attribute_group pwm_fan_group = { | |
170 | .attrs = pwm_fan_attrs, | |
171 | .is_visible = pwm_fan_attrs_visible, | |
172 | }; | |
173 | ||
174 | static const struct attribute_group *pwm_fan_groups[] = { | |
175 | &pwm_fan_group, | |
176 | NULL, | |
177 | }; | |
d82d5776 | 178 | |
b6bddec0 LM |
179 | /* thermal cooling device callbacks */ |
180 | static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev, | |
181 | unsigned long *state) | |
182 | { | |
183 | struct pwm_fan_ctx *ctx = cdev->devdata; | |
184 | ||
185 | if (!ctx) | |
186 | return -EINVAL; | |
187 | ||
188 | *state = ctx->pwm_fan_max_state; | |
189 | ||
190 | return 0; | |
191 | } | |
192 | ||
193 | static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev, | |
194 | unsigned long *state) | |
195 | { | |
196 | struct pwm_fan_ctx *ctx = cdev->devdata; | |
197 | ||
198 | if (!ctx) | |
199 | return -EINVAL; | |
200 | ||
201 | *state = ctx->pwm_fan_state; | |
202 | ||
203 | return 0; | |
204 | } | |
205 | ||
206 | static int | |
207 | pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state) | |
208 | { | |
209 | struct pwm_fan_ctx *ctx = cdev->devdata; | |
210 | int ret; | |
211 | ||
212 | if (!ctx || (state > ctx->pwm_fan_max_state)) | |
213 | return -EINVAL; | |
214 | ||
215 | if (state == ctx->pwm_fan_state) | |
216 | return 0; | |
217 | ||
218 | ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]); | |
219 | if (ret) { | |
220 | dev_err(&cdev->device, "Cannot set pwm!\n"); | |
221 | return ret; | |
222 | } | |
223 | ||
224 | ctx->pwm_fan_state = state; | |
225 | ||
226 | return ret; | |
227 | } | |
228 | ||
229 | static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = { | |
230 | .get_max_state = pwm_fan_get_max_state, | |
231 | .get_cur_state = pwm_fan_get_cur_state, | |
232 | .set_cur_state = pwm_fan_set_cur_state, | |
233 | }; | |
234 | ||
de52b049 GR |
235 | static int pwm_fan_of_get_cooling_data(struct device *dev, |
236 | struct pwm_fan_ctx *ctx) | |
2e5219c7 LM |
237 | { |
238 | struct device_node *np = dev->of_node; | |
239 | int num, i, ret; | |
240 | ||
241 | if (!of_find_property(np, "cooling-levels", NULL)) | |
242 | return 0; | |
243 | ||
244 | ret = of_property_count_u32_elems(np, "cooling-levels"); | |
245 | if (ret <= 0) { | |
246 | dev_err(dev, "Wrong data!\n"); | |
247 | return ret ? : -EINVAL; | |
248 | } | |
249 | ||
250 | num = ret; | |
a86854d0 | 251 | ctx->pwm_fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32), |
2e5219c7 LM |
252 | GFP_KERNEL); |
253 | if (!ctx->pwm_fan_cooling_levels) | |
254 | return -ENOMEM; | |
255 | ||
256 | ret = of_property_read_u32_array(np, "cooling-levels", | |
257 | ctx->pwm_fan_cooling_levels, num); | |
258 | if (ret) { | |
259 | dev_err(dev, "Property 'cooling-levels' cannot be read!\n"); | |
260 | return ret; | |
261 | } | |
262 | ||
263 | for (i = 0; i < num; i++) { | |
264 | if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) { | |
265 | dev_err(dev, "PWM fan state[%d]:%d > %d\n", i, | |
266 | ctx->pwm_fan_cooling_levels[i], MAX_PWM); | |
267 | return -EINVAL; | |
268 | } | |
269 | } | |
270 | ||
271 | ctx->pwm_fan_max_state = num - 1; | |
272 | ||
273 | return 0; | |
274 | } | |
275 | ||
d82d5776 KD |
276 | static int pwm_fan_probe(struct platform_device *pdev) |
277 | { | |
b6bddec0 | 278 | struct thermal_cooling_device *cdev; |
d82d5776 | 279 | struct pwm_fan_ctx *ctx; |
b6bddec0 | 280 | struct device *hwmon; |
d82d5776 | 281 | int ret; |
677252a1 | 282 | struct pwm_state state = { }; |
6b1ec478 | 283 | u32 ppr = 2; |
d82d5776 KD |
284 | |
285 | ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); | |
286 | if (!ctx) | |
287 | return -ENOMEM; | |
288 | ||
289 | mutex_init(&ctx->lock); | |
290 | ||
291 | ctx->pwm = devm_of_pwm_get(&pdev->dev, pdev->dev.of_node, NULL); | |
292 | if (IS_ERR(ctx->pwm)) { | |
9f67f758 TR |
293 | ret = PTR_ERR(ctx->pwm); |
294 | ||
295 | if (ret != -EPROBE_DEFER) | |
296 | dev_err(&pdev->dev, "Could not get PWM: %d\n", ret); | |
297 | ||
298 | return ret; | |
d82d5776 KD |
299 | } |
300 | ||
d82d5776 KD |
301 | platform_set_drvdata(pdev, ctx); |
302 | ||
6b1ec478 SW |
303 | ctx->irq = platform_get_irq(pdev, 0); |
304 | if (ctx->irq == -EPROBE_DEFER) | |
305 | return ctx->irq; | |
306 | ||
b57e1d42 SW |
307 | ctx->reg_en = devm_regulator_get_optional(&pdev->dev, "fan"); |
308 | if (IS_ERR(ctx->reg_en)) { | |
309 | if (PTR_ERR(ctx->reg_en) != -ENODEV) | |
310 | return PTR_ERR(ctx->reg_en); | |
311 | ||
312 | ctx->reg_en = NULL; | |
313 | } else { | |
314 | ret = regulator_enable(ctx->reg_en); | |
315 | if (ret) { | |
316 | dev_err(&pdev->dev, | |
317 | "Failed to enable fan supply: %d\n", ret); | |
318 | return ret; | |
319 | } | |
320 | } | |
321 | ||
d82d5776 KD |
322 | ctx->pwm_value = MAX_PWM; |
323 | ||
677252a1 BZ |
324 | /* Set duty cycle to maximum allowed and enable PWM output */ |
325 | pwm_init_state(ctx->pwm, &state); | |
326 | state.duty_cycle = ctx->pwm->args.period - 1; | |
327 | state.enabled = true; | |
d82d5776 | 328 | |
677252a1 | 329 | ret = pwm_apply_state(ctx->pwm, &state); |
d82d5776 | 330 | if (ret) { |
841cf676 | 331 | dev_err(&pdev->dev, "Failed to configure PWM: %d\n", ret); |
b57e1d42 | 332 | goto err_reg_disable; |
d82d5776 KD |
333 | } |
334 | ||
6b1ec478 SW |
335 | timer_setup(&ctx->rpm_timer, sample_timer, 0); |
336 | ||
337 | of_property_read_u32(pdev->dev.of_node, "pulses-per-revolution", &ppr); | |
338 | ctx->pulses_per_revolution = ppr; | |
339 | if (!ctx->pulses_per_revolution) { | |
340 | dev_err(&pdev->dev, "pulses-per-revolution can't be zero.\n"); | |
341 | ret = -EINVAL; | |
342 | goto err_pwm_disable; | |
343 | } | |
344 | ||
345 | if (ctx->irq > 0) { | |
346 | ret = devm_request_irq(&pdev->dev, ctx->irq, pulse_handler, 0, | |
347 | pdev->name, ctx); | |
348 | if (ret) { | |
841cf676 RM |
349 | dev_err(&pdev->dev, |
350 | "Failed to request interrupt: %d\n", ret); | |
6b1ec478 SW |
351 | goto err_pwm_disable; |
352 | } | |
353 | ctx->sample_start = ktime_get(); | |
354 | mod_timer(&ctx->rpm_timer, jiffies + HZ); | |
355 | } | |
356 | ||
d82d5776 KD |
357 | hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan", |
358 | ctx, pwm_fan_groups); | |
359 | if (IS_ERR(hwmon)) { | |
677252a1 | 360 | ret = PTR_ERR(hwmon); |
841cf676 RM |
361 | dev_err(&pdev->dev, |
362 | "Failed to register hwmon device: %d\n", ret); | |
6b1ec478 | 363 | goto err_del_timer; |
d82d5776 | 364 | } |
2e5219c7 LM |
365 | |
366 | ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx); | |
367 | if (ret) | |
6b1ec478 | 368 | goto err_del_timer; |
2e5219c7 | 369 | |
b6bddec0 LM |
370 | ctx->pwm_fan_state = ctx->pwm_fan_max_state; |
371 | if (IS_ENABLED(CONFIG_THERMAL)) { | |
372 | cdev = thermal_of_cooling_device_register(pdev->dev.of_node, | |
373 | "pwm-fan", ctx, | |
374 | &pwm_fan_cooling_ops); | |
375 | if (IS_ERR(cdev)) { | |
677252a1 | 376 | ret = PTR_ERR(cdev); |
841cf676 RM |
377 | dev_err(&pdev->dev, |
378 | "Failed to register pwm-fan as cooling device: %d\n", | |
379 | ret); | |
6b1ec478 | 380 | goto err_del_timer; |
b6bddec0 LM |
381 | } |
382 | ctx->cdev = cdev; | |
383 | thermal_cdev_update(cdev); | |
384 | } | |
385 | ||
d82d5776 | 386 | return 0; |
677252a1 | 387 | |
6b1ec478 SW |
388 | err_del_timer: |
389 | del_timer_sync(&ctx->rpm_timer); | |
390 | ||
677252a1 BZ |
391 | err_pwm_disable: |
392 | state.enabled = false; | |
393 | pwm_apply_state(ctx->pwm, &state); | |
394 | ||
b57e1d42 SW |
395 | err_reg_disable: |
396 | if (ctx->reg_en) | |
397 | regulator_disable(ctx->reg_en); | |
398 | ||
677252a1 | 399 | return ret; |
d82d5776 KD |
400 | } |
401 | ||
402 | static int pwm_fan_remove(struct platform_device *pdev) | |
403 | { | |
404 | struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev); | |
405 | ||
b6bddec0 | 406 | thermal_cooling_device_unregister(ctx->cdev); |
6b1ec478 SW |
407 | del_timer_sync(&ctx->rpm_timer); |
408 | ||
d82d5776 KD |
409 | if (ctx->pwm_value) |
410 | pwm_disable(ctx->pwm); | |
b57e1d42 SW |
411 | |
412 | if (ctx->reg_en) | |
413 | regulator_disable(ctx->reg_en); | |
414 | ||
d82d5776 KD |
415 | return 0; |
416 | } | |
417 | ||
418 | #ifdef CONFIG_PM_SLEEP | |
419 | static int pwm_fan_suspend(struct device *dev) | |
420 | { | |
421 | struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); | |
95dcd64b TR |
422 | struct pwm_args args; |
423 | int ret; | |
424 | ||
425 | pwm_get_args(ctx->pwm, &args); | |
426 | ||
427 | if (ctx->pwm_value) { | |
428 | ret = pwm_config(ctx->pwm, 0, args.period); | |
429 | if (ret < 0) | |
430 | return ret; | |
d82d5776 | 431 | |
d82d5776 | 432 | pwm_disable(ctx->pwm); |
95dcd64b TR |
433 | } |
434 | ||
b57e1d42 SW |
435 | if (ctx->reg_en) { |
436 | ret = regulator_disable(ctx->reg_en); | |
437 | if (ret) { | |
438 | dev_err(dev, "Failed to disable fan supply: %d\n", ret); | |
439 | return ret; | |
440 | } | |
441 | } | |
442 | ||
d82d5776 KD |
443 | return 0; |
444 | } | |
445 | ||
446 | static int pwm_fan_resume(struct device *dev) | |
447 | { | |
448 | struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); | |
2289711c | 449 | struct pwm_args pargs; |
48b9d5b4 KD |
450 | unsigned long duty; |
451 | int ret; | |
d82d5776 | 452 | |
b57e1d42 SW |
453 | if (ctx->reg_en) { |
454 | ret = regulator_enable(ctx->reg_en); | |
455 | if (ret) { | |
456 | dev_err(dev, "Failed to enable fan supply: %d\n", ret); | |
457 | return ret; | |
458 | } | |
459 | } | |
460 | ||
48b9d5b4 KD |
461 | if (ctx->pwm_value == 0) |
462 | return 0; | |
463 | ||
2289711c BB |
464 | pwm_get_args(ctx->pwm, &pargs); |
465 | duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM); | |
466 | ret = pwm_config(ctx->pwm, duty, pargs.period); | |
48b9d5b4 KD |
467 | if (ret) |
468 | return ret; | |
469 | return pwm_enable(ctx->pwm); | |
d82d5776 KD |
470 | } |
471 | #endif | |
472 | ||
473 | static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume); | |
474 | ||
d720acac | 475 | static const struct of_device_id of_pwm_fan_match[] = { |
d82d5776 KD |
476 | { .compatible = "pwm-fan", }, |
477 | {}, | |
478 | }; | |
f491e70c | 479 | MODULE_DEVICE_TABLE(of, of_pwm_fan_match); |
d82d5776 KD |
480 | |
481 | static struct platform_driver pwm_fan_driver = { | |
482 | .probe = pwm_fan_probe, | |
483 | .remove = pwm_fan_remove, | |
484 | .driver = { | |
485 | .name = "pwm-fan", | |
486 | .pm = &pwm_fan_pm, | |
487 | .of_match_table = of_pwm_fan_match, | |
488 | }, | |
489 | }; | |
490 | ||
491 | module_platform_driver(pwm_fan_driver); | |
492 | ||
493 | MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>"); | |
494 | MODULE_ALIAS("platform:pwm-fan"); | |
495 | MODULE_DESCRIPTION("PWM FAN driver"); | |
496 | MODULE_LICENSE("GPL"); |