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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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * gpio-fan.c - Hwmon driver for fans connected to GPIO lines.
4 *
5 * Copyright (C) 2010 LaCie
6 *
7 * Author: Simon Guinot <sguinot@lacie.com>
8 */
9
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/slab.h>
13#include <linux/interrupt.h>
14#include <linux/irq.h>
15#include <linux/platform_device.h>
16#include <linux/err.h>
17#include <linux/kstrtox.h>
18#include <linux/mutex.h>
19#include <linux/hwmon.h>
20#include <linux/gpio/consumer.h>
21#include <linux/of.h>
22#include <linux/of_platform.h>
23#include <linux/thermal.h>
24
25struct gpio_fan_speed {
26 int rpm;
27 int ctrl_val;
28};
29
30struct gpio_fan_data {
31 struct device *dev;
32 struct device *hwmon_dev;
33 /* Cooling device if any */
34 struct thermal_cooling_device *cdev;
35 struct mutex lock; /* lock GPIOs operations. */
36 int num_gpios;
37 struct gpio_desc **gpios;
38 int num_speed;
39 struct gpio_fan_speed *speed;
40 int speed_index;
41 int resume_speed;
42 bool pwm_enable;
43 struct gpio_desc *alarm_gpio;
44 struct work_struct alarm_work;
45};
46
47/*
48 * Alarm GPIO.
49 */
50
51static void fan_alarm_notify(struct work_struct *ws)
52{
53 struct gpio_fan_data *fan_data =
54 container_of(ws, struct gpio_fan_data, alarm_work);
55
56 sysfs_notify(&fan_data->hwmon_dev->kobj, NULL, "fan1_alarm");
57 kobject_uevent(&fan_data->hwmon_dev->kobj, KOBJ_CHANGE);
58}
59
60static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
61{
62 struct gpio_fan_data *fan_data = dev_id;
63
64 schedule_work(&fan_data->alarm_work);
65
66 return IRQ_NONE;
67}
68
69static ssize_t fan1_alarm_show(struct device *dev,
70 struct device_attribute *attr, char *buf)
71{
72 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
73
74 return sprintf(buf, "%d\n",
75 gpiod_get_value_cansleep(fan_data->alarm_gpio));
76}
77
78static DEVICE_ATTR_RO(fan1_alarm);
79
80static int fan_alarm_init(struct gpio_fan_data *fan_data)
81{
82 int alarm_irq;
83 struct device *dev = fan_data->dev;
84
85 /*
86 * If the alarm GPIO don't support interrupts, just leave
87 * without initializing the fail notification support.
88 */
89 alarm_irq = gpiod_to_irq(fan_data->alarm_gpio);
90 if (alarm_irq <= 0)
91 return 0;
92
93 INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
94 irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
95 return devm_request_irq(dev, alarm_irq, fan_alarm_irq_handler,
96 IRQF_SHARED, "GPIO fan alarm", fan_data);
97}
98
99/*
100 * Control GPIOs.
101 */
102
103/* Must be called with fan_data->lock held, except during initialization. */
104static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
105{
106 int i;
107
108 for (i = 0; i < fan_data->num_gpios; i++)
109 gpiod_set_value_cansleep(fan_data->gpios[i],
110 (ctrl_val >> i) & 1);
111}
112
113static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
114{
115 int i;
116 int ctrl_val = 0;
117
118 for (i = 0; i < fan_data->num_gpios; i++) {
119 int value;
120
121 value = gpiod_get_value_cansleep(fan_data->gpios[i]);
122 ctrl_val |= (value << i);
123 }
124 return ctrl_val;
125}
126
127/* Must be called with fan_data->lock held, except during initialization. */
128static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
129{
130 if (fan_data->speed_index == speed_index)
131 return;
132
133 __set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
134 fan_data->speed_index = speed_index;
135}
136
137static int get_fan_speed_index(struct gpio_fan_data *fan_data)
138{
139 int ctrl_val = __get_fan_ctrl(fan_data);
140 int i;
141
142 for (i = 0; i < fan_data->num_speed; i++)
143 if (fan_data->speed[i].ctrl_val == ctrl_val)
144 return i;
145
146 dev_warn(fan_data->dev,
147 "missing speed array entry for GPIO value 0x%x\n", ctrl_val);
148
149 return -ENODEV;
150}
151
152static int rpm_to_speed_index(struct gpio_fan_data *fan_data, unsigned long rpm)
153{
154 struct gpio_fan_speed *speed = fan_data->speed;
155 int i;
156
157 for (i = 0; i < fan_data->num_speed; i++)
158 if (speed[i].rpm >= rpm)
159 return i;
160
161 return fan_data->num_speed - 1;
162}
163
164static ssize_t pwm1_show(struct device *dev, struct device_attribute *attr,
165 char *buf)
166{
167 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
168 u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);
169
170 return sprintf(buf, "%d\n", pwm);
171}
172
173static ssize_t pwm1_store(struct device *dev, struct device_attribute *attr,
174 const char *buf, size_t count)
175{
176 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
177 unsigned long pwm;
178 int speed_index;
179 int ret = count;
180
181 if (kstrtoul(buf, 10, &pwm) || pwm > 255)
182 return -EINVAL;
183
184 mutex_lock(&fan_data->lock);
185
186 if (!fan_data->pwm_enable) {
187 ret = -EPERM;
188 goto exit_unlock;
189 }
190
191 speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
192 set_fan_speed(fan_data, speed_index);
193
194exit_unlock:
195 mutex_unlock(&fan_data->lock);
196
197 return ret;
198}
199
200static ssize_t pwm1_enable_show(struct device *dev,
201 struct device_attribute *attr, char *buf)
202{
203 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
204
205 return sprintf(buf, "%d\n", fan_data->pwm_enable);
206}
207
208static ssize_t pwm1_enable_store(struct device *dev,
209 struct device_attribute *attr,
210 const char *buf, size_t count)
211{
212 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
213 unsigned long val;
214
215 if (kstrtoul(buf, 10, &val) || val > 1)
216 return -EINVAL;
217
218 if (fan_data->pwm_enable == val)
219 return count;
220
221 mutex_lock(&fan_data->lock);
222
223 fan_data->pwm_enable = val;
224
225 /* Disable manual control mode: set fan at full speed. */
226 if (val == 0)
227 set_fan_speed(fan_data, fan_data->num_speed - 1);
228
229 mutex_unlock(&fan_data->lock);
230
231 return count;
232}
233
234static ssize_t pwm1_mode_show(struct device *dev,
235 struct device_attribute *attr, char *buf)
236{
237 return sprintf(buf, "0\n");
238}
239
240static ssize_t fan1_min_show(struct device *dev,
241 struct device_attribute *attr, char *buf)
242{
243 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
244
245 return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
246}
247
248static ssize_t fan1_max_show(struct device *dev,
249 struct device_attribute *attr, char *buf)
250{
251 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
252
253 return sprintf(buf, "%d\n",
254 fan_data->speed[fan_data->num_speed - 1].rpm);
255}
256
257static ssize_t fan1_input_show(struct device *dev,
258 struct device_attribute *attr, char *buf)
259{
260 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
261
262 return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
263}
264
265static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
266 const char *buf, size_t count)
267{
268 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
269 unsigned long rpm;
270 int ret = count;
271
272 if (kstrtoul(buf, 10, &rpm))
273 return -EINVAL;
274
275 mutex_lock(&fan_data->lock);
276
277 if (!fan_data->pwm_enable) {
278 ret = -EPERM;
279 goto exit_unlock;
280 }
281
282 set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
283
284exit_unlock:
285 mutex_unlock(&fan_data->lock);
286
287 return ret;
288}
289
290static DEVICE_ATTR_RW(pwm1);
291static DEVICE_ATTR_RW(pwm1_enable);
292static DEVICE_ATTR_RO(pwm1_mode);
293static DEVICE_ATTR_RO(fan1_min);
294static DEVICE_ATTR_RO(fan1_max);
295static DEVICE_ATTR_RO(fan1_input);
296static DEVICE_ATTR(fan1_target, 0644, fan1_input_show, set_rpm);
297
298static umode_t gpio_fan_is_visible(struct kobject *kobj,
299 struct attribute *attr, int index)
300{
301 struct device *dev = kobj_to_dev(kobj);
302 struct gpio_fan_data *data = dev_get_drvdata(dev);
303
304 if (index == 0 && !data->alarm_gpio)
305 return 0;
306 if (index > 0 && !data->gpios)
307 return 0;
308
309 return attr->mode;
310}
311
312static struct attribute *gpio_fan_attributes[] = {
313 &dev_attr_fan1_alarm.attr, /* 0 */
314 &dev_attr_pwm1.attr, /* 1 */
315 &dev_attr_pwm1_enable.attr,
316 &dev_attr_pwm1_mode.attr,
317 &dev_attr_fan1_input.attr,
318 &dev_attr_fan1_target.attr,
319 &dev_attr_fan1_min.attr,
320 &dev_attr_fan1_max.attr,
321 NULL
322};
323
324static const struct attribute_group gpio_fan_group = {
325 .attrs = gpio_fan_attributes,
326 .is_visible = gpio_fan_is_visible,
327};
328
329static const struct attribute_group *gpio_fan_groups[] = {
330 &gpio_fan_group,
331 NULL
332};
333
334static int fan_ctrl_init(struct gpio_fan_data *fan_data)
335{
336 int num_gpios = fan_data->num_gpios;
337 struct gpio_desc **gpios = fan_data->gpios;
338 int i, err;
339
340 for (i = 0; i < num_gpios; i++) {
341 /*
342 * The GPIO descriptors were retrieved with GPIOD_ASIS so here
343 * we set the GPIO into output mode, carefully preserving the
344 * current value by setting it to whatever it is already set
345 * (no surprise changes in default fan speed).
346 */
347 err = gpiod_direction_output(gpios[i],
348 gpiod_get_value_cansleep(gpios[i]));
349 if (err)
350 return err;
351 }
352
353 fan_data->pwm_enable = true; /* Enable manual fan speed control. */
354 fan_data->speed_index = get_fan_speed_index(fan_data);
355 if (fan_data->speed_index < 0)
356 return fan_data->speed_index;
357
358 return 0;
359}
360
361static int gpio_fan_get_max_state(struct thermal_cooling_device *cdev,
362 unsigned long *state)
363{
364 struct gpio_fan_data *fan_data = cdev->devdata;
365
366 if (!fan_data)
367 return -EINVAL;
368
369 *state = fan_data->num_speed - 1;
370 return 0;
371}
372
373static int gpio_fan_get_cur_state(struct thermal_cooling_device *cdev,
374 unsigned long *state)
375{
376 struct gpio_fan_data *fan_data = cdev->devdata;
377
378 if (!fan_data)
379 return -EINVAL;
380
381 *state = fan_data->speed_index;
382 return 0;
383}
384
385static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev,
386 unsigned long state)
387{
388 struct gpio_fan_data *fan_data = cdev->devdata;
389
390 if (!fan_data)
391 return -EINVAL;
392
393 if (state >= fan_data->num_speed)
394 return -EINVAL;
395
396 set_fan_speed(fan_data, state);
397 return 0;
398}
399
400static const struct thermal_cooling_device_ops gpio_fan_cool_ops = {
401 .get_max_state = gpio_fan_get_max_state,
402 .get_cur_state = gpio_fan_get_cur_state,
403 .set_cur_state = gpio_fan_set_cur_state,
404};
405
406/*
407 * Translate OpenFirmware node properties into platform_data
408 */
409static int gpio_fan_get_of_data(struct gpio_fan_data *fan_data)
410{
411 struct gpio_fan_speed *speed;
412 struct device *dev = fan_data->dev;
413 struct device_node *np = dev->of_node;
414 struct gpio_desc **gpios;
415 unsigned i;
416 u32 u;
417 struct property *prop;
418 const __be32 *p;
419
420 /* Alarm GPIO if one exists */
421 fan_data->alarm_gpio = devm_gpiod_get_optional(dev, "alarm", GPIOD_IN);
422 if (IS_ERR(fan_data->alarm_gpio))
423 return PTR_ERR(fan_data->alarm_gpio);
424
425 /* Fill GPIO pin array */
426 fan_data->num_gpios = gpiod_count(dev, NULL);
427 if (fan_data->num_gpios <= 0) {
428 if (fan_data->alarm_gpio)
429 return 0;
430 dev_err(dev, "DT properties empty / missing");
431 return -ENODEV;
432 }
433 gpios = devm_kcalloc(dev,
434 fan_data->num_gpios, sizeof(struct gpio_desc *),
435 GFP_KERNEL);
436 if (!gpios)
437 return -ENOMEM;
438 for (i = 0; i < fan_data->num_gpios; i++) {
439 gpios[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
440 if (IS_ERR(gpios[i]))
441 return PTR_ERR(gpios[i]);
442 }
443 fan_data->gpios = gpios;
444
445 /* Get number of RPM/ctrl_val pairs in speed map */
446 prop = of_find_property(np, "gpio-fan,speed-map", &i);
447 if (!prop) {
448 dev_err(dev, "gpio-fan,speed-map DT property missing");
449 return -ENODEV;
450 }
451 i = i / sizeof(u32);
452 if (i == 0 || i & 1) {
453 dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
454 return -ENODEV;
455 }
456 fan_data->num_speed = i / 2;
457
458 /*
459 * Populate speed map
460 * Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
461 * this needs splitting into pairs to create gpio_fan_speed structs
462 */
463 speed = devm_kcalloc(dev,
464 fan_data->num_speed, sizeof(struct gpio_fan_speed),
465 GFP_KERNEL);
466 if (!speed)
467 return -ENOMEM;
468 p = NULL;
469 for (i = 0; i < fan_data->num_speed; i++) {
470 p = of_prop_next_u32(prop, p, &u);
471 if (!p)
472 return -ENODEV;
473 speed[i].rpm = u;
474 p = of_prop_next_u32(prop, p, &u);
475 if (!p)
476 return -ENODEV;
477 speed[i].ctrl_val = u;
478 }
479 fan_data->speed = speed;
480
481 return 0;
482}
483
484static const struct of_device_id of_gpio_fan_match[] = {
485 { .compatible = "gpio-fan", },
486 {},
487};
488MODULE_DEVICE_TABLE(of, of_gpio_fan_match);
489
490static void gpio_fan_stop(void *data)
491{
492 set_fan_speed(data, 0);
493}
494
495static int gpio_fan_probe(struct platform_device *pdev)
496{
497 int err;
498 struct gpio_fan_data *fan_data;
499 struct device *dev = &pdev->dev;
500 struct device_node *np = dev->of_node;
501
502 fan_data = devm_kzalloc(dev, sizeof(struct gpio_fan_data),
503 GFP_KERNEL);
504 if (!fan_data)
505 return -ENOMEM;
506
507 fan_data->dev = dev;
508 err = gpio_fan_get_of_data(fan_data);
509 if (err)
510 return err;
511
512 platform_set_drvdata(pdev, fan_data);
513 mutex_init(&fan_data->lock);
514
515 /* Configure control GPIOs if available. */
516 if (fan_data->gpios && fan_data->num_gpios > 0) {
517 if (!fan_data->speed || fan_data->num_speed <= 1)
518 return -EINVAL;
519 err = fan_ctrl_init(fan_data);
520 if (err)
521 return err;
522 err = devm_add_action_or_reset(dev, gpio_fan_stop, fan_data);
523 if (err)
524 return err;
525 }
526
527 /* Make this driver part of hwmon class. */
528 fan_data->hwmon_dev =
529 devm_hwmon_device_register_with_groups(dev,
530 "gpio_fan", fan_data,
531 gpio_fan_groups);
532 if (IS_ERR(fan_data->hwmon_dev))
533 return PTR_ERR(fan_data->hwmon_dev);
534
535 /* Configure alarm GPIO if available. */
536 if (fan_data->alarm_gpio) {
537 err = fan_alarm_init(fan_data);
538 if (err)
539 return err;
540 }
541
542 /* Optional cooling device register for Device tree platforms */
543 fan_data->cdev = devm_thermal_of_cooling_device_register(dev, np,
544 "gpio-fan", fan_data, &gpio_fan_cool_ops);
545
546 dev_info(dev, "GPIO fan initialized\n");
547
548 return 0;
549}
550
551static void gpio_fan_shutdown(struct platform_device *pdev)
552{
553 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
554
555 if (fan_data->gpios)
556 set_fan_speed(fan_data, 0);
557}
558
559static int gpio_fan_suspend(struct device *dev)
560{
561 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
562
563 if (fan_data->gpios) {
564 fan_data->resume_speed = fan_data->speed_index;
565 set_fan_speed(fan_data, 0);
566 }
567
568 return 0;
569}
570
571static int gpio_fan_resume(struct device *dev)
572{
573 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
574
575 if (fan_data->gpios)
576 set_fan_speed(fan_data, fan_data->resume_speed);
577
578 return 0;
579}
580
581static DEFINE_SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);
582
583static struct platform_driver gpio_fan_driver = {
584 .probe = gpio_fan_probe,
585 .shutdown = gpio_fan_shutdown,
586 .driver = {
587 .name = "gpio-fan",
588 .pm = pm_sleep_ptr(&gpio_fan_pm),
589 .of_match_table = of_gpio_fan_match,
590 },
591};
592
593module_platform_driver(gpio_fan_driver);
594
595MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
596MODULE_DESCRIPTION("GPIO FAN driver");
597MODULE_LICENSE("GPL");
598MODULE_ALIAS("platform:gpio-fan");