Merge remote-tracking branches 'asoc/fix/tlv320aic3x' and 'asoc/fix/wm8962' into...
[firefly-linux-kernel-4.4.55.git] / drivers / hwmon / pwm-fan.c
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
31 struct 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
41 static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
42 {
43         unsigned long duty;
44         int ret = 0;
45
46         mutex_lock(&ctx->lock);
47         if (ctx->pwm_value == pwm)
48                 goto exit_set_pwm_err;
49
50         duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM);
51         ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
52         if (ret)
53                 goto exit_set_pwm_err;
54
55         if (pwm == 0)
56                 pwm_disable(ctx->pwm);
57
58         if (ctx->pwm_value == 0) {
59                 ret = pwm_enable(ctx->pwm);
60                 if (ret)
61                         goto exit_set_pwm_err;
62         }
63
64         ctx->pwm_value = pwm;
65 exit_set_pwm_err:
66         mutex_unlock(&ctx->lock);
67         return ret;
68 }
69
70 static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
71 {
72         int i;
73
74         for (i = 0; i < ctx->pwm_fan_max_state; ++i)
75                 if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
76                         break;
77
78         ctx->pwm_fan_state = i;
79 }
80
81 static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
82                        const char *buf, size_t count)
83 {
84         struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
85         unsigned long pwm;
86         int ret;
87
88         if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM)
89                 return -EINVAL;
90
91         ret = __set_pwm(ctx, pwm);
92         if (ret)
93                 return ret;
94
95         pwm_fan_update_state(ctx, pwm);
96         return count;
97 }
98
99 static ssize_t show_pwm(struct device *dev,
100                         struct device_attribute *attr, char *buf)
101 {
102         struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
103
104         return sprintf(buf, "%u\n", ctx->pwm_value);
105 }
106
107
108 static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm, 0);
109
110 static struct attribute *pwm_fan_attrs[] = {
111         &sensor_dev_attr_pwm1.dev_attr.attr,
112         NULL,
113 };
114
115 ATTRIBUTE_GROUPS(pwm_fan);
116
117 /* thermal cooling device callbacks */
118 static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
119                                  unsigned long *state)
120 {
121         struct pwm_fan_ctx *ctx = cdev->devdata;
122
123         if (!ctx)
124                 return -EINVAL;
125
126         *state = ctx->pwm_fan_max_state;
127
128         return 0;
129 }
130
131 static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
132                                  unsigned long *state)
133 {
134         struct pwm_fan_ctx *ctx = cdev->devdata;
135
136         if (!ctx)
137                 return -EINVAL;
138
139         *state = ctx->pwm_fan_state;
140
141         return 0;
142 }
143
144 static int
145 pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
146 {
147         struct pwm_fan_ctx *ctx = cdev->devdata;
148         int ret;
149
150         if (!ctx || (state > ctx->pwm_fan_max_state))
151                 return -EINVAL;
152
153         if (state == ctx->pwm_fan_state)
154                 return 0;
155
156         ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
157         if (ret) {
158                 dev_err(&cdev->device, "Cannot set pwm!\n");
159                 return ret;
160         }
161
162         ctx->pwm_fan_state = state;
163
164         return ret;
165 }
166
167 static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
168         .get_max_state = pwm_fan_get_max_state,
169         .get_cur_state = pwm_fan_get_cur_state,
170         .set_cur_state = pwm_fan_set_cur_state,
171 };
172
173 static int pwm_fan_of_get_cooling_data(struct device *dev,
174                                        struct pwm_fan_ctx *ctx)
175 {
176         struct device_node *np = dev->of_node;
177         int num, i, ret;
178
179         if (!of_find_property(np, "cooling-levels", NULL))
180                 return 0;
181
182         ret = of_property_count_u32_elems(np, "cooling-levels");
183         if (ret <= 0) {
184                 dev_err(dev, "Wrong data!\n");
185                 return ret ? : -EINVAL;
186         }
187
188         num = ret;
189         ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32),
190                                                    GFP_KERNEL);
191         if (!ctx->pwm_fan_cooling_levels)
192                 return -ENOMEM;
193
194         ret = of_property_read_u32_array(np, "cooling-levels",
195                                          ctx->pwm_fan_cooling_levels, num);
196         if (ret) {
197                 dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
198                 return ret;
199         }
200
201         for (i = 0; i < num; i++) {
202                 if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
203                         dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
204                                 ctx->pwm_fan_cooling_levels[i], MAX_PWM);
205                         return -EINVAL;
206                 }
207         }
208
209         ctx->pwm_fan_max_state = num - 1;
210
211         return 0;
212 }
213
214 static int pwm_fan_probe(struct platform_device *pdev)
215 {
216         struct thermal_cooling_device *cdev;
217         struct pwm_fan_ctx *ctx;
218         struct device *hwmon;
219         int duty_cycle;
220         int ret;
221
222         ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
223         if (!ctx)
224                 return -ENOMEM;
225
226         mutex_init(&ctx->lock);
227
228         ctx->pwm = devm_of_pwm_get(&pdev->dev, pdev->dev.of_node, NULL);
229         if (IS_ERR(ctx->pwm)) {
230                 dev_err(&pdev->dev, "Could not get PWM\n");
231                 return PTR_ERR(ctx->pwm);
232         }
233
234         platform_set_drvdata(pdev, ctx);
235
236         /* Set duty cycle to maximum allowed */
237         duty_cycle = ctx->pwm->period - 1;
238         ctx->pwm_value = MAX_PWM;
239
240         ret = pwm_config(ctx->pwm, duty_cycle, ctx->pwm->period);
241         if (ret) {
242                 dev_err(&pdev->dev, "Failed to configure PWM\n");
243                 return ret;
244         }
245
246         /* Enbale PWM output */
247         ret = pwm_enable(ctx->pwm);
248         if (ret) {
249                 dev_err(&pdev->dev, "Failed to enable PWM\n");
250                 return ret;
251         }
252
253         hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
254                                                        ctx, pwm_fan_groups);
255         if (IS_ERR(hwmon)) {
256                 dev_err(&pdev->dev, "Failed to register hwmon device\n");
257                 pwm_disable(ctx->pwm);
258                 return PTR_ERR(hwmon);
259         }
260
261         ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx);
262         if (ret)
263                 return ret;
264
265         ctx->pwm_fan_state = ctx->pwm_fan_max_state;
266         if (IS_ENABLED(CONFIG_THERMAL)) {
267                 cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
268                                                           "pwm-fan", ctx,
269                                                           &pwm_fan_cooling_ops);
270                 if (IS_ERR(cdev)) {
271                         dev_err(&pdev->dev,
272                                 "Failed to register pwm-fan as cooling device");
273                         pwm_disable(ctx->pwm);
274                         return PTR_ERR(cdev);
275                 }
276                 ctx->cdev = cdev;
277                 thermal_cdev_update(cdev);
278         }
279
280         return 0;
281 }
282
283 static int pwm_fan_remove(struct platform_device *pdev)
284 {
285         struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
286
287         thermal_cooling_device_unregister(ctx->cdev);
288         if (ctx->pwm_value)
289                 pwm_disable(ctx->pwm);
290         return 0;
291 }
292
293 #ifdef CONFIG_PM_SLEEP
294 static int pwm_fan_suspend(struct device *dev)
295 {
296         struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
297
298         if (ctx->pwm_value)
299                 pwm_disable(ctx->pwm);
300         return 0;
301 }
302
303 static int pwm_fan_resume(struct device *dev)
304 {
305         struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
306         unsigned long duty;
307         int ret;
308
309         if (ctx->pwm_value == 0)
310                 return 0;
311
312         duty = DIV_ROUND_UP(ctx->pwm_value * (ctx->pwm->period - 1), MAX_PWM);
313         ret = pwm_config(ctx->pwm, duty, ctx->pwm->period);
314         if (ret)
315                 return ret;
316         return pwm_enable(ctx->pwm);
317 }
318 #endif
319
320 static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
321
322 static const struct of_device_id of_pwm_fan_match[] = {
323         { .compatible = "pwm-fan", },
324         {},
325 };
326 MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
327
328 static struct platform_driver pwm_fan_driver = {
329         .probe          = pwm_fan_probe,
330         .remove         = pwm_fan_remove,
331         .driver = {
332                 .name           = "pwm-fan",
333                 .pm             = &pwm_fan_pm,
334                 .of_match_table = of_pwm_fan_match,
335         },
336 };
337
338 module_platform_driver(pwm_fan_driver);
339
340 MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
341 MODULE_ALIAS("platform:pwm-fan");
342 MODULE_DESCRIPTION("PWM FAN driver");
343 MODULE_LICENSE("GPL");