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1/*
2 * gpio-fan.c - Hwmon driver for fans connected to GPIO lines.
3 *
4 * Copyright (C) 2010 LaCie
5 *
6 * Author: Simon Guinot <sguinot@lacie.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 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/slab.h>
26#include <linux/interrupt.h>
27#include <linux/irq.h>
28#include <linux/platform_device.h>
29#include <linux/err.h>
30#include <linux/mutex.h>
31#include <linux/hwmon.h>
32#include <linux/gpio.h>
33#include <linux/gpio-fan.h>
34
35struct gpio_fan_data {
36 struct platform_device *pdev;
37 struct device *hwmon_dev;
38 struct mutex lock; /* lock GPIOs operations. */
39 int num_ctrl;
40 unsigned *ctrl;
41 int num_speed;
42 struct gpio_fan_speed *speed;
43 int speed_index;
44#ifdef CONFIG_PM
45 int resume_speed;
46#endif
47 bool pwm_enable;
48 struct gpio_fan_alarm *alarm;
49 struct work_struct alarm_work;
50};
51
52/*
53 * Alarm GPIO.
54 */
55
56static void fan_alarm_notify(struct work_struct *ws)
57{
58 struct gpio_fan_data *fan_data =
59 container_of(ws, struct gpio_fan_data, alarm_work);
60
61 sysfs_notify(&fan_data->pdev->dev.kobj, NULL, "fan1_alarm");
62 kobject_uevent(&fan_data->pdev->dev.kobj, KOBJ_CHANGE);
63}
64
65static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
66{
67 struct gpio_fan_data *fan_data = dev_id;
68
69 schedule_work(&fan_data->alarm_work);
70
71 return IRQ_NONE;
72}
73
74static ssize_t show_fan_alarm(struct device *dev,
75 struct device_attribute *attr, char *buf)
76{
77 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
78 struct gpio_fan_alarm *alarm = fan_data->alarm;
79 int value = gpio_get_value(alarm->gpio);
80
81 if (alarm->active_low)
82 value = !value;
83
84 return sprintf(buf, "%d\n", value);
85}
86
87static DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL);
88
89static int fan_alarm_init(struct gpio_fan_data *fan_data,
90 struct gpio_fan_alarm *alarm)
91{
92 int err;
93 int alarm_irq;
94 struct platform_device *pdev = fan_data->pdev;
95
96 fan_data->alarm = alarm;
97
98 err = gpio_request(alarm->gpio, "GPIO fan alarm");
99 if (err)
100 return err;
101
102 err = gpio_direction_input(alarm->gpio);
103 if (err)
104 goto err_free_gpio;
105
106 err = device_create_file(&pdev->dev, &dev_attr_fan1_alarm);
107 if (err)
108 goto err_free_gpio;
109
110 /*
111 * If the alarm GPIO don't support interrupts, just leave
112 * without initializing the fail notification support.
113 */
114 alarm_irq = gpio_to_irq(alarm->gpio);
115 if (alarm_irq < 0)
116 return 0;
117
118 INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
119 irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
120 err = request_irq(alarm_irq, fan_alarm_irq_handler, IRQF_SHARED,
121 "GPIO fan alarm", fan_data);
122 if (err)
123 goto err_free_sysfs;
124
125 return 0;
126
127err_free_sysfs:
128 device_remove_file(&pdev->dev, &dev_attr_fan1_alarm);
129err_free_gpio:
130 gpio_free(alarm->gpio);
131
132 return err;
133}
134
135static void fan_alarm_free(struct gpio_fan_data *fan_data)
136{
137 struct platform_device *pdev = fan_data->pdev;
138 int alarm_irq = gpio_to_irq(fan_data->alarm->gpio);
139
140 if (alarm_irq >= 0)
141 free_irq(alarm_irq, fan_data);
142 device_remove_file(&pdev->dev, &dev_attr_fan1_alarm);
143 gpio_free(fan_data->alarm->gpio);
144}
145
146/*
147 * Control GPIOs.
148 */
149
150/* Must be called with fan_data->lock held, except during initialization. */
151static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
152{
153 int i;
154
155 for (i = 0; i < fan_data->num_ctrl; i++)
156 gpio_set_value(fan_data->ctrl[i], (ctrl_val >> i) & 1);
157}
158
159static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
160{
161 int i;
162 int ctrl_val = 0;
163
164 for (i = 0; i < fan_data->num_ctrl; i++) {
165 int value;
166
167 value = gpio_get_value(fan_data->ctrl[i]);
168 ctrl_val |= (value << i);
169 }
170 return ctrl_val;
171}
172
173/* Must be called with fan_data->lock held, except during initialization. */
174static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
175{
176 if (fan_data->speed_index == speed_index)
177 return;
178
179 __set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
180 fan_data->speed_index = speed_index;
181}
182
183static int get_fan_speed_index(struct gpio_fan_data *fan_data)
184{
185 int ctrl_val = __get_fan_ctrl(fan_data);
186 int i;
187
188 for (i = 0; i < fan_data->num_speed; i++)
189 if (fan_data->speed[i].ctrl_val == ctrl_val)
190 return i;
191
192 dev_warn(&fan_data->pdev->dev,
193 "missing speed array entry for GPIO value 0x%x\n", ctrl_val);
194
195 return -EINVAL;
196}
197
198static int rpm_to_speed_index(struct gpio_fan_data *fan_data, int rpm)
199{
200 struct gpio_fan_speed *speed = fan_data->speed;
201 int i;
202
203 for (i = 0; i < fan_data->num_speed; i++)
204 if (speed[i].rpm >= rpm)
205 return i;
206
207 return fan_data->num_speed - 1;
208}
209
210static ssize_t show_pwm(struct device *dev,
211 struct device_attribute *attr, char *buf)
212{
213 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
214 u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);
215
216 return sprintf(buf, "%d\n", pwm);
217}
218
219static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
220 const char *buf, size_t count)
221{
222 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
223 unsigned long pwm;
224 int speed_index;
225 int ret = count;
226
227 if (strict_strtoul(buf, 10, &pwm) || pwm > 255)
228 return -EINVAL;
229
230 mutex_lock(&fan_data->lock);
231
232 if (!fan_data->pwm_enable) {
233 ret = -EPERM;
234 goto exit_unlock;
235 }
236
237 speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
238 set_fan_speed(fan_data, speed_index);
239
240exit_unlock:
241 mutex_unlock(&fan_data->lock);
242
243 return ret;
244}
245
246static ssize_t show_pwm_enable(struct device *dev,
247 struct device_attribute *attr, char *buf)
248{
249 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
250
251 return sprintf(buf, "%d\n", fan_data->pwm_enable);
252}
253
254static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *attr,
255 const char *buf, size_t count)
256{
257 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
258 unsigned long val;
259
260 if (strict_strtoul(buf, 10, &val) || val > 1)
261 return -EINVAL;
262
263 if (fan_data->pwm_enable == val)
264 return count;
265
266 mutex_lock(&fan_data->lock);
267
268 fan_data->pwm_enable = val;
269
270 /* Disable manual control mode: set fan at full speed. */
271 if (val == 0)
272 set_fan_speed(fan_data, fan_data->num_speed - 1);
273
274 mutex_unlock(&fan_data->lock);
275
276 return count;
277}
278
279static ssize_t show_pwm_mode(struct device *dev,
280 struct device_attribute *attr, char *buf)
281{
282 return sprintf(buf, "0\n");
283}
284
285static ssize_t show_rpm_min(struct device *dev,
286 struct device_attribute *attr, char *buf)
287{
288 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
289
290 return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
291}
292
293static ssize_t show_rpm_max(struct device *dev,
294 struct device_attribute *attr, char *buf)
295{
296 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
297
298 return sprintf(buf, "%d\n",
299 fan_data->speed[fan_data->num_speed - 1].rpm);
300}
301
302static ssize_t show_rpm(struct device *dev,
303 struct device_attribute *attr, char *buf)
304{
305 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
306
307 return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
308}
309
310static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
311 const char *buf, size_t count)
312{
313 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
314 unsigned long rpm;
315 int ret = count;
316
317 if (strict_strtoul(buf, 10, &rpm))
318 return -EINVAL;
319
320 mutex_lock(&fan_data->lock);
321
322 if (!fan_data->pwm_enable) {
323 ret = -EPERM;
324 goto exit_unlock;
325 }
326
327 set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
328
329exit_unlock:
330 mutex_unlock(&fan_data->lock);
331
332 return ret;
333}
334
335static DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm);
336static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
337 show_pwm_enable, set_pwm_enable);
338static DEVICE_ATTR(pwm1_mode, S_IRUGO, show_pwm_mode, NULL);
339static DEVICE_ATTR(fan1_min, S_IRUGO, show_rpm_min, NULL);
340static DEVICE_ATTR(fan1_max, S_IRUGO, show_rpm_max, NULL);
341static DEVICE_ATTR(fan1_input, S_IRUGO, show_rpm, NULL);
342static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_rpm, set_rpm);
343
344static struct attribute *gpio_fan_ctrl_attributes[] = {
345 &dev_attr_pwm1.attr,
346 &dev_attr_pwm1_enable.attr,
347 &dev_attr_pwm1_mode.attr,
348 &dev_attr_fan1_input.attr,
349 &dev_attr_fan1_target.attr,
350 &dev_attr_fan1_min.attr,
351 &dev_attr_fan1_max.attr,
352 NULL
353};
354
355static const struct attribute_group gpio_fan_ctrl_group = {
356 .attrs = gpio_fan_ctrl_attributes,
357};
358
359static int fan_ctrl_init(struct gpio_fan_data *fan_data,
360 struct gpio_fan_platform_data *pdata)
361{
362 struct platform_device *pdev = fan_data->pdev;
363 int num_ctrl = pdata->num_ctrl;
364 unsigned *ctrl = pdata->ctrl;
365 int i, err;
366
367 for (i = 0; i < num_ctrl; i++) {
368 err = gpio_request(ctrl[i], "GPIO fan control");
369 if (err)
370 goto err_free_gpio;
371
372 err = gpio_direction_output(ctrl[i], gpio_get_value(ctrl[i]));
373 if (err) {
374 gpio_free(ctrl[i]);
375 goto err_free_gpio;
376 }
377 }
378
379 fan_data->num_ctrl = num_ctrl;
380 fan_data->ctrl = ctrl;
381 fan_data->num_speed = pdata->num_speed;
382 fan_data->speed = pdata->speed;
383 fan_data->pwm_enable = true; /* Enable manual fan speed control. */
384 fan_data->speed_index = get_fan_speed_index(fan_data);
385 if (fan_data->speed_index < 0) {
386 err = -ENODEV;
387 goto err_free_gpio;
388 }
389
390 err = sysfs_create_group(&pdev->dev.kobj, &gpio_fan_ctrl_group);
391 if (err)
392 goto err_free_gpio;
393
394 return 0;
395
396err_free_gpio:
397 for (i = i - 1; i >= 0; i--)
398 gpio_free(ctrl[i]);
399
400 return err;
401}
402
403static void fan_ctrl_free(struct gpio_fan_data *fan_data)
404{
405 struct platform_device *pdev = fan_data->pdev;
406 int i;
407
408 sysfs_remove_group(&pdev->dev.kobj, &gpio_fan_ctrl_group);
409 for (i = 0; i < fan_data->num_ctrl; i++)
410 gpio_free(fan_data->ctrl[i]);
411}
412
413/*
414 * Platform driver.
415 */
416
417static ssize_t show_name(struct device *dev,
418 struct device_attribute *attr, char *buf)
419{
420 return sprintf(buf, "gpio-fan\n");
421}
422
423static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
424
425static int __devinit gpio_fan_probe(struct platform_device *pdev)
426{
427 int err;
428 struct gpio_fan_data *fan_data;
429 struct gpio_fan_platform_data *pdata = pdev->dev.platform_data;
430
431 if (!pdata)
432 return -EINVAL;
433
434 fan_data = kzalloc(sizeof(struct gpio_fan_data), GFP_KERNEL);
435 if (!fan_data)
436 return -ENOMEM;
437
438 fan_data->pdev = pdev;
439 platform_set_drvdata(pdev, fan_data);
440 mutex_init(&fan_data->lock);
441
442 /* Configure alarm GPIO if available. */
443 if (pdata->alarm) {
444 err = fan_alarm_init(fan_data, pdata->alarm);
445 if (err)
446 goto err_free_data;
447 }
448
449 /* Configure control GPIOs if available. */
450 if (pdata->ctrl && pdata->num_ctrl > 0) {
451 if (!pdata->speed || pdata->num_speed <= 1) {
452 err = -EINVAL;
453 goto err_free_alarm;
454 }
455 err = fan_ctrl_init(fan_data, pdata);
456 if (err)
457 goto err_free_alarm;
458 }
459
460 err = device_create_file(&pdev->dev, &dev_attr_name);
461 if (err)
462 goto err_free_ctrl;
463
464 /* Make this driver part of hwmon class. */
465 fan_data->hwmon_dev = hwmon_device_register(&pdev->dev);
466 if (IS_ERR(fan_data->hwmon_dev)) {
467 err = PTR_ERR(fan_data->hwmon_dev);
468 goto err_remove_name;
469 }
470
471 dev_info(&pdev->dev, "GPIO fan initialized\n");
472
473 return 0;
474
475err_remove_name:
476 device_remove_file(&pdev->dev, &dev_attr_name);
477err_free_ctrl:
478 if (fan_data->ctrl)
479 fan_ctrl_free(fan_data);
480err_free_alarm:
481 if (fan_data->alarm)
482 fan_alarm_free(fan_data);
483err_free_data:
484 platform_set_drvdata(pdev, NULL);
485 kfree(fan_data);
486
487 return err;
488}
489
490static int __devexit gpio_fan_remove(struct platform_device *pdev)
491{
492 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
493
494 hwmon_device_unregister(fan_data->hwmon_dev);
495 device_remove_file(&pdev->dev, &dev_attr_name);
496 if (fan_data->alarm)
497 fan_alarm_free(fan_data);
498 if (fan_data->ctrl)
499 fan_ctrl_free(fan_data);
500 kfree(fan_data);
501
502 return 0;
503}
504
505#ifdef CONFIG_PM
506static int gpio_fan_suspend(struct platform_device *pdev, pm_message_t state)
507{
508 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
509
510 if (fan_data->ctrl) {
511 fan_data->resume_speed = fan_data->speed_index;
512 set_fan_speed(fan_data, 0);
513 }
514
515 return 0;
516}
517
518static int gpio_fan_resume(struct platform_device *pdev)
519{
520 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
521
522 if (fan_data->ctrl)
523 set_fan_speed(fan_data, fan_data->resume_speed);
524
525 return 0;
526}
527#else
528#define gpio_fan_suspend NULL
529#define gpio_fan_resume NULL
530#endif
531
532static struct platform_driver gpio_fan_driver = {
533 .probe = gpio_fan_probe,
534 .remove = __devexit_p(gpio_fan_remove),
535 .suspend = gpio_fan_suspend,
536 .resume = gpio_fan_resume,
537 .driver = {
538 .name = "gpio-fan",
539 },
540};
541
542static int __init gpio_fan_init(void)
543{
544 return platform_driver_register(&gpio_fan_driver);
545}
546
547static void __exit gpio_fan_exit(void)
548{
549 platform_driver_unregister(&gpio_fan_driver);
550}
551
552module_init(gpio_fan_init);
553module_exit(gpio_fan_exit);
554
555MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
556MODULE_DESCRIPTION("GPIO FAN driver");
557MODULE_LICENSE("GPL");
558MODULE_ALIAS("platform:gpio-fan");
1/*
2 * gpio-fan.c - Hwmon driver for fans connected to GPIO lines.
3 *
4 * Copyright (C) 2010 LaCie
5 *
6 * Author: Simon Guinot <sguinot@lacie.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 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/slab.h>
26#include <linux/interrupt.h>
27#include <linux/irq.h>
28#include <linux/platform_device.h>
29#include <linux/err.h>
30#include <linux/mutex.h>
31#include <linux/hwmon.h>
32#include <linux/gpio.h>
33#include <linux/gpio-fan.h>
34#include <linux/of.h>
35#include <linux/of_platform.h>
36#include <linux/of_gpio.h>
37
38struct gpio_fan_data {
39 struct platform_device *pdev;
40 struct device *hwmon_dev;
41 struct mutex lock; /* lock GPIOs operations. */
42 int num_ctrl;
43 unsigned *ctrl;
44 int num_speed;
45 struct gpio_fan_speed *speed;
46 int speed_index;
47#ifdef CONFIG_PM_SLEEP
48 int resume_speed;
49#endif
50 bool pwm_enable;
51 struct gpio_fan_alarm *alarm;
52 struct work_struct alarm_work;
53};
54
55/*
56 * Alarm GPIO.
57 */
58
59static void fan_alarm_notify(struct work_struct *ws)
60{
61 struct gpio_fan_data *fan_data =
62 container_of(ws, struct gpio_fan_data, alarm_work);
63
64 sysfs_notify(&fan_data->pdev->dev.kobj, NULL, "fan1_alarm");
65 kobject_uevent(&fan_data->pdev->dev.kobj, KOBJ_CHANGE);
66}
67
68static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
69{
70 struct gpio_fan_data *fan_data = dev_id;
71
72 schedule_work(&fan_data->alarm_work);
73
74 return IRQ_NONE;
75}
76
77static ssize_t show_fan_alarm(struct device *dev,
78 struct device_attribute *attr, char *buf)
79{
80 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
81 struct gpio_fan_alarm *alarm = fan_data->alarm;
82 int value = gpio_get_value(alarm->gpio);
83
84 if (alarm->active_low)
85 value = !value;
86
87 return sprintf(buf, "%d\n", value);
88}
89
90static DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL);
91
92static int fan_alarm_init(struct gpio_fan_data *fan_data,
93 struct gpio_fan_alarm *alarm)
94{
95 int err;
96 int alarm_irq;
97 struct platform_device *pdev = fan_data->pdev;
98
99 fan_data->alarm = alarm;
100
101 err = devm_gpio_request(&pdev->dev, alarm->gpio, "GPIO fan alarm");
102 if (err)
103 return err;
104
105 err = gpio_direction_input(alarm->gpio);
106 if (err)
107 return err;
108
109 /*
110 * If the alarm GPIO don't support interrupts, just leave
111 * without initializing the fail notification support.
112 */
113 alarm_irq = gpio_to_irq(alarm->gpio);
114 if (alarm_irq < 0)
115 return 0;
116
117 INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
118 irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
119 err = devm_request_irq(&pdev->dev, alarm_irq, fan_alarm_irq_handler,
120 IRQF_SHARED, "GPIO fan alarm", fan_data);
121 return err;
122}
123
124/*
125 * Control GPIOs.
126 */
127
128/* Must be called with fan_data->lock held, except during initialization. */
129static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
130{
131 int i;
132
133 for (i = 0; i < fan_data->num_ctrl; i++)
134 gpio_set_value(fan_data->ctrl[i], (ctrl_val >> i) & 1);
135}
136
137static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
138{
139 int i;
140 int ctrl_val = 0;
141
142 for (i = 0; i < fan_data->num_ctrl; i++) {
143 int value;
144
145 value = gpio_get_value(fan_data->ctrl[i]);
146 ctrl_val |= (value << i);
147 }
148 return ctrl_val;
149}
150
151/* Must be called with fan_data->lock held, except during initialization. */
152static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
153{
154 if (fan_data->speed_index == speed_index)
155 return;
156
157 __set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
158 fan_data->speed_index = speed_index;
159}
160
161static int get_fan_speed_index(struct gpio_fan_data *fan_data)
162{
163 int ctrl_val = __get_fan_ctrl(fan_data);
164 int i;
165
166 for (i = 0; i < fan_data->num_speed; i++)
167 if (fan_data->speed[i].ctrl_val == ctrl_val)
168 return i;
169
170 dev_warn(&fan_data->pdev->dev,
171 "missing speed array entry for GPIO value 0x%x\n", ctrl_val);
172
173 return -ENODEV;
174}
175
176static int rpm_to_speed_index(struct gpio_fan_data *fan_data, int rpm)
177{
178 struct gpio_fan_speed *speed = fan_data->speed;
179 int i;
180
181 for (i = 0; i < fan_data->num_speed; i++)
182 if (speed[i].rpm >= rpm)
183 return i;
184
185 return fan_data->num_speed - 1;
186}
187
188static ssize_t show_pwm(struct device *dev,
189 struct device_attribute *attr, char *buf)
190{
191 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
192 u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);
193
194 return sprintf(buf, "%d\n", pwm);
195}
196
197static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
198 const char *buf, size_t count)
199{
200 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
201 unsigned long pwm;
202 int speed_index;
203 int ret = count;
204
205 if (kstrtoul(buf, 10, &pwm) || pwm > 255)
206 return -EINVAL;
207
208 mutex_lock(&fan_data->lock);
209
210 if (!fan_data->pwm_enable) {
211 ret = -EPERM;
212 goto exit_unlock;
213 }
214
215 speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
216 set_fan_speed(fan_data, speed_index);
217
218exit_unlock:
219 mutex_unlock(&fan_data->lock);
220
221 return ret;
222}
223
224static ssize_t show_pwm_enable(struct device *dev,
225 struct device_attribute *attr, char *buf)
226{
227 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
228
229 return sprintf(buf, "%d\n", fan_data->pwm_enable);
230}
231
232static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *attr,
233 const char *buf, size_t count)
234{
235 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
236 unsigned long val;
237
238 if (kstrtoul(buf, 10, &val) || val > 1)
239 return -EINVAL;
240
241 if (fan_data->pwm_enable == val)
242 return count;
243
244 mutex_lock(&fan_data->lock);
245
246 fan_data->pwm_enable = val;
247
248 /* Disable manual control mode: set fan at full speed. */
249 if (val == 0)
250 set_fan_speed(fan_data, fan_data->num_speed - 1);
251
252 mutex_unlock(&fan_data->lock);
253
254 return count;
255}
256
257static ssize_t show_pwm_mode(struct device *dev,
258 struct device_attribute *attr, char *buf)
259{
260 return sprintf(buf, "0\n");
261}
262
263static ssize_t show_rpm_min(struct device *dev,
264 struct device_attribute *attr, char *buf)
265{
266 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
267
268 return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
269}
270
271static ssize_t show_rpm_max(struct device *dev,
272 struct device_attribute *attr, char *buf)
273{
274 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
275
276 return sprintf(buf, "%d\n",
277 fan_data->speed[fan_data->num_speed - 1].rpm);
278}
279
280static ssize_t show_rpm(struct device *dev,
281 struct device_attribute *attr, char *buf)
282{
283 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
284
285 return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
286}
287
288static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
289 const char *buf, size_t count)
290{
291 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
292 unsigned long rpm;
293 int ret = count;
294
295 if (kstrtoul(buf, 10, &rpm))
296 return -EINVAL;
297
298 mutex_lock(&fan_data->lock);
299
300 if (!fan_data->pwm_enable) {
301 ret = -EPERM;
302 goto exit_unlock;
303 }
304
305 set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
306
307exit_unlock:
308 mutex_unlock(&fan_data->lock);
309
310 return ret;
311}
312
313static DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm);
314static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
315 show_pwm_enable, set_pwm_enable);
316static DEVICE_ATTR(pwm1_mode, S_IRUGO, show_pwm_mode, NULL);
317static DEVICE_ATTR(fan1_min, S_IRUGO, show_rpm_min, NULL);
318static DEVICE_ATTR(fan1_max, S_IRUGO, show_rpm_max, NULL);
319static DEVICE_ATTR(fan1_input, S_IRUGO, show_rpm, NULL);
320static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_rpm, set_rpm);
321
322static umode_t gpio_fan_is_visible(struct kobject *kobj,
323 struct attribute *attr, int index)
324{
325 struct device *dev = container_of(kobj, struct device, kobj);
326 struct gpio_fan_data *data = dev_get_drvdata(dev);
327
328 if (index == 0 && !data->alarm)
329 return 0;
330 if (index > 0 && !data->ctrl)
331 return 0;
332
333 return attr->mode;
334}
335
336static struct attribute *gpio_fan_attributes[] = {
337 &dev_attr_fan1_alarm.attr, /* 0 */
338 &dev_attr_pwm1.attr, /* 1 */
339 &dev_attr_pwm1_enable.attr,
340 &dev_attr_pwm1_mode.attr,
341 &dev_attr_fan1_input.attr,
342 &dev_attr_fan1_target.attr,
343 &dev_attr_fan1_min.attr,
344 &dev_attr_fan1_max.attr,
345 NULL
346};
347
348static const struct attribute_group gpio_fan_group = {
349 .attrs = gpio_fan_attributes,
350 .is_visible = gpio_fan_is_visible,
351};
352
353static const struct attribute_group *gpio_fan_groups[] = {
354 &gpio_fan_group,
355 NULL
356};
357
358static int fan_ctrl_init(struct gpio_fan_data *fan_data,
359 struct gpio_fan_platform_data *pdata)
360{
361 struct platform_device *pdev = fan_data->pdev;
362 int num_ctrl = pdata->num_ctrl;
363 unsigned *ctrl = pdata->ctrl;
364 int i, err;
365
366 for (i = 0; i < num_ctrl; i++) {
367 err = devm_gpio_request(&pdev->dev, ctrl[i],
368 "GPIO fan control");
369 if (err)
370 return err;
371
372 err = gpio_direction_output(ctrl[i], gpio_get_value(ctrl[i]));
373 if (err)
374 return err;
375 }
376
377 fan_data->num_ctrl = num_ctrl;
378 fan_data->ctrl = ctrl;
379 fan_data->num_speed = pdata->num_speed;
380 fan_data->speed = pdata->speed;
381 fan_data->pwm_enable = true; /* Enable manual fan speed control. */
382 fan_data->speed_index = get_fan_speed_index(fan_data);
383 if (fan_data->speed_index < 0)
384 return fan_data->speed_index;
385
386 return 0;
387}
388
389#ifdef CONFIG_OF_GPIO
390/*
391 * Translate OpenFirmware node properties into platform_data
392 */
393static int gpio_fan_get_of_pdata(struct device *dev,
394 struct gpio_fan_platform_data *pdata)
395{
396 struct device_node *node;
397 struct gpio_fan_speed *speed;
398 unsigned *ctrl;
399 unsigned i;
400 u32 u;
401 struct property *prop;
402 const __be32 *p;
403
404 node = dev->of_node;
405
406 /* Fill GPIO pin array */
407 pdata->num_ctrl = of_gpio_count(node);
408 if (pdata->num_ctrl <= 0) {
409 dev_err(dev, "gpios DT property empty / missing");
410 return -ENODEV;
411 }
412 ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned),
413 GFP_KERNEL);
414 if (!ctrl)
415 return -ENOMEM;
416 for (i = 0; i < pdata->num_ctrl; i++) {
417 int val;
418
419 val = of_get_gpio(node, i);
420 if (val < 0)
421 return val;
422 ctrl[i] = val;
423 }
424 pdata->ctrl = ctrl;
425
426 /* Get number of RPM/ctrl_val pairs in speed map */
427 prop = of_find_property(node, "gpio-fan,speed-map", &i);
428 if (!prop) {
429 dev_err(dev, "gpio-fan,speed-map DT property missing");
430 return -ENODEV;
431 }
432 i = i / sizeof(u32);
433 if (i == 0 || i & 1) {
434 dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
435 return -ENODEV;
436 }
437 pdata->num_speed = i / 2;
438
439 /*
440 * Populate speed map
441 * Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
442 * this needs splitting into pairs to create gpio_fan_speed structs
443 */
444 speed = devm_kzalloc(dev,
445 pdata->num_speed * sizeof(struct gpio_fan_speed),
446 GFP_KERNEL);
447 if (!speed)
448 return -ENOMEM;
449 p = NULL;
450 for (i = 0; i < pdata->num_speed; i++) {
451 p = of_prop_next_u32(prop, p, &u);
452 if (!p)
453 return -ENODEV;
454 speed[i].rpm = u;
455 p = of_prop_next_u32(prop, p, &u);
456 if (!p)
457 return -ENODEV;
458 speed[i].ctrl_val = u;
459 }
460 pdata->speed = speed;
461
462 /* Alarm GPIO if one exists */
463 if (of_gpio_named_count(node, "alarm-gpios") > 0) {
464 struct gpio_fan_alarm *alarm;
465 int val;
466 enum of_gpio_flags flags;
467
468 alarm = devm_kzalloc(dev, sizeof(struct gpio_fan_alarm),
469 GFP_KERNEL);
470 if (!alarm)
471 return -ENOMEM;
472
473 val = of_get_named_gpio_flags(node, "alarm-gpios", 0, &flags);
474 if (val < 0)
475 return val;
476 alarm->gpio = val;
477 alarm->active_low = flags & OF_GPIO_ACTIVE_LOW;
478
479 pdata->alarm = alarm;
480 }
481
482 return 0;
483}
484
485static struct of_device_id of_gpio_fan_match[] = {
486 { .compatible = "gpio-fan", },
487 {},
488};
489#endif /* CONFIG_OF_GPIO */
490
491static int gpio_fan_probe(struct platform_device *pdev)
492{
493 int err;
494 struct gpio_fan_data *fan_data;
495 struct gpio_fan_platform_data *pdata = dev_get_platdata(&pdev->dev);
496
497#ifdef CONFIG_OF_GPIO
498 if (!pdata) {
499 pdata = devm_kzalloc(&pdev->dev,
500 sizeof(struct gpio_fan_platform_data),
501 GFP_KERNEL);
502 if (!pdata)
503 return -ENOMEM;
504
505 err = gpio_fan_get_of_pdata(&pdev->dev, pdata);
506 if (err)
507 return err;
508 }
509#else /* CONFIG_OF_GPIO */
510 if (!pdata)
511 return -EINVAL;
512#endif /* CONFIG_OF_GPIO */
513
514 fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data),
515 GFP_KERNEL);
516 if (!fan_data)
517 return -ENOMEM;
518
519 fan_data->pdev = pdev;
520 platform_set_drvdata(pdev, fan_data);
521 mutex_init(&fan_data->lock);
522
523 /* Configure alarm GPIO if available. */
524 if (pdata->alarm) {
525 err = fan_alarm_init(fan_data, pdata->alarm);
526 if (err)
527 return err;
528 }
529
530 /* Configure control GPIOs if available. */
531 if (pdata->ctrl && pdata->num_ctrl > 0) {
532 if (!pdata->speed || pdata->num_speed <= 1)
533 return -EINVAL;
534 err = fan_ctrl_init(fan_data, pdata);
535 if (err)
536 return err;
537 }
538
539 /* Make this driver part of hwmon class. */
540 fan_data->hwmon_dev = hwmon_device_register_with_groups(&pdev->dev,
541 "gpio-fan", fan_data,
542 gpio_fan_groups);
543 if (IS_ERR(fan_data->hwmon_dev))
544 return PTR_ERR(fan_data->hwmon_dev);
545
546 dev_info(&pdev->dev, "GPIO fan initialized\n");
547
548 return 0;
549}
550
551static int gpio_fan_remove(struct platform_device *pdev)
552{
553 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
554
555 hwmon_device_unregister(fan_data->hwmon_dev);
556
557 return 0;
558}
559
560#ifdef CONFIG_PM_SLEEP
561static int gpio_fan_suspend(struct device *dev)
562{
563 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
564
565 if (fan_data->ctrl) {
566 fan_data->resume_speed = fan_data->speed_index;
567 set_fan_speed(fan_data, 0);
568 }
569
570 return 0;
571}
572
573static int gpio_fan_resume(struct device *dev)
574{
575 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
576
577 if (fan_data->ctrl)
578 set_fan_speed(fan_data, fan_data->resume_speed);
579
580 return 0;
581}
582
583static SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);
584#define GPIO_FAN_PM (&gpio_fan_pm)
585#else
586#define GPIO_FAN_PM NULL
587#endif
588
589static struct platform_driver gpio_fan_driver = {
590 .probe = gpio_fan_probe,
591 .remove = gpio_fan_remove,
592 .driver = {
593 .name = "gpio-fan",
594 .pm = GPIO_FAN_PM,
595#ifdef CONFIG_OF_GPIO
596 .of_match_table = of_match_ptr(of_gpio_fan_match),
597#endif
598 },
599};
600
601module_platform_driver(gpio_fan_driver);
602
603MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
604MODULE_DESCRIPTION("GPIO FAN driver");
605MODULE_LICENSE("GPL");
606MODULE_ALIAS("platform:gpio-fan");