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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#include <linux/of.h>
35#include <linux/of_platform.h>
36#include <linux/of_gpio.h>
37#include <linux/thermal.h>
38
39struct gpio_fan_data {
40 struct platform_device *pdev;
41 struct device *hwmon_dev;
42 /* Cooling device if any */
43 struct thermal_cooling_device *cdev;
44 struct mutex lock; /* lock GPIOs operations. */
45 int num_ctrl;
46 unsigned *ctrl;
47 int num_speed;
48 struct gpio_fan_speed *speed;
49 int speed_index;
50#ifdef CONFIG_PM_SLEEP
51 int resume_speed;
52#endif
53 bool pwm_enable;
54 struct gpio_fan_alarm *alarm;
55 struct work_struct alarm_work;
56};
57
58/*
59 * Alarm GPIO.
60 */
61
62static void fan_alarm_notify(struct work_struct *ws)
63{
64 struct gpio_fan_data *fan_data =
65 container_of(ws, struct gpio_fan_data, alarm_work);
66
67 sysfs_notify(&fan_data->pdev->dev.kobj, NULL, "fan1_alarm");
68 kobject_uevent(&fan_data->pdev->dev.kobj, KOBJ_CHANGE);
69}
70
71static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
72{
73 struct gpio_fan_data *fan_data = dev_id;
74
75 schedule_work(&fan_data->alarm_work);
76
77 return IRQ_NONE;
78}
79
80static ssize_t show_fan_alarm(struct device *dev,
81 struct device_attribute *attr, char *buf)
82{
83 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
84 struct gpio_fan_alarm *alarm = fan_data->alarm;
85 int value = gpio_get_value_cansleep(alarm->gpio);
86
87 if (alarm->active_low)
88 value = !value;
89
90 return sprintf(buf, "%d\n", value);
91}
92
93static DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL);
94
95static int fan_alarm_init(struct gpio_fan_data *fan_data,
96 struct gpio_fan_alarm *alarm)
97{
98 int err;
99 int alarm_irq;
100 struct platform_device *pdev = fan_data->pdev;
101
102 fan_data->alarm = alarm;
103
104 err = devm_gpio_request(&pdev->dev, alarm->gpio, "GPIO fan alarm");
105 if (err)
106 return err;
107
108 err = gpio_direction_input(alarm->gpio);
109 if (err)
110 return err;
111
112 /*
113 * If the alarm GPIO don't support interrupts, just leave
114 * without initializing the fail notification support.
115 */
116 alarm_irq = gpio_to_irq(alarm->gpio);
117 if (alarm_irq < 0)
118 return 0;
119
120 INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
121 irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
122 err = devm_request_irq(&pdev->dev, alarm_irq, fan_alarm_irq_handler,
123 IRQF_SHARED, "GPIO fan alarm", fan_data);
124 return err;
125}
126
127/*
128 * Control GPIOs.
129 */
130
131/* Must be called with fan_data->lock held, except during initialization. */
132static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
133{
134 int i;
135
136 for (i = 0; i < fan_data->num_ctrl; i++)
137 gpio_set_value_cansleep(fan_data->ctrl[i], (ctrl_val >> i) & 1);
138}
139
140static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
141{
142 int i;
143 int ctrl_val = 0;
144
145 for (i = 0; i < fan_data->num_ctrl; i++) {
146 int value;
147
148 value = gpio_get_value_cansleep(fan_data->ctrl[i]);
149 ctrl_val |= (value << i);
150 }
151 return ctrl_val;
152}
153
154/* Must be called with fan_data->lock held, except during initialization. */
155static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
156{
157 if (fan_data->speed_index == speed_index)
158 return;
159
160 __set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
161 fan_data->speed_index = speed_index;
162}
163
164static int get_fan_speed_index(struct gpio_fan_data *fan_data)
165{
166 int ctrl_val = __get_fan_ctrl(fan_data);
167 int i;
168
169 for (i = 0; i < fan_data->num_speed; i++)
170 if (fan_data->speed[i].ctrl_val == ctrl_val)
171 return i;
172
173 dev_warn(&fan_data->pdev->dev,
174 "missing speed array entry for GPIO value 0x%x\n", ctrl_val);
175
176 return -ENODEV;
177}
178
179static int rpm_to_speed_index(struct gpio_fan_data *fan_data, unsigned long rpm)
180{
181 struct gpio_fan_speed *speed = fan_data->speed;
182 int i;
183
184 for (i = 0; i < fan_data->num_speed; i++)
185 if (speed[i].rpm >= rpm)
186 return i;
187
188 return fan_data->num_speed - 1;
189}
190
191static ssize_t show_pwm(struct device *dev,
192 struct device_attribute *attr, char *buf)
193{
194 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
195 u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);
196
197 return sprintf(buf, "%d\n", pwm);
198}
199
200static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
201 const char *buf, size_t count)
202{
203 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
204 unsigned long pwm;
205 int speed_index;
206 int ret = count;
207
208 if (kstrtoul(buf, 10, &pwm) || pwm > 255)
209 return -EINVAL;
210
211 mutex_lock(&fan_data->lock);
212
213 if (!fan_data->pwm_enable) {
214 ret = -EPERM;
215 goto exit_unlock;
216 }
217
218 speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
219 set_fan_speed(fan_data, speed_index);
220
221exit_unlock:
222 mutex_unlock(&fan_data->lock);
223
224 return ret;
225}
226
227static ssize_t show_pwm_enable(struct device *dev,
228 struct device_attribute *attr, char *buf)
229{
230 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
231
232 return sprintf(buf, "%d\n", fan_data->pwm_enable);
233}
234
235static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *attr,
236 const char *buf, size_t count)
237{
238 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
239 unsigned long val;
240
241 if (kstrtoul(buf, 10, &val) || val > 1)
242 return -EINVAL;
243
244 if (fan_data->pwm_enable == val)
245 return count;
246
247 mutex_lock(&fan_data->lock);
248
249 fan_data->pwm_enable = val;
250
251 /* Disable manual control mode: set fan at full speed. */
252 if (val == 0)
253 set_fan_speed(fan_data, fan_data->num_speed - 1);
254
255 mutex_unlock(&fan_data->lock);
256
257 return count;
258}
259
260static ssize_t show_pwm_mode(struct device *dev,
261 struct device_attribute *attr, char *buf)
262{
263 return sprintf(buf, "0\n");
264}
265
266static ssize_t show_rpm_min(struct device *dev,
267 struct device_attribute *attr, char *buf)
268{
269 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
270
271 return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
272}
273
274static ssize_t show_rpm_max(struct device *dev,
275 struct device_attribute *attr, char *buf)
276{
277 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
278
279 return sprintf(buf, "%d\n",
280 fan_data->speed[fan_data->num_speed - 1].rpm);
281}
282
283static ssize_t show_rpm(struct device *dev,
284 struct device_attribute *attr, char *buf)
285{
286 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
287
288 return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
289}
290
291static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
292 const char *buf, size_t count)
293{
294 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
295 unsigned long rpm;
296 int ret = count;
297
298 if (kstrtoul(buf, 10, &rpm))
299 return -EINVAL;
300
301 mutex_lock(&fan_data->lock);
302
303 if (!fan_data->pwm_enable) {
304 ret = -EPERM;
305 goto exit_unlock;
306 }
307
308 set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
309
310exit_unlock:
311 mutex_unlock(&fan_data->lock);
312
313 return ret;
314}
315
316static DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm);
317static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
318 show_pwm_enable, set_pwm_enable);
319static DEVICE_ATTR(pwm1_mode, S_IRUGO, show_pwm_mode, NULL);
320static DEVICE_ATTR(fan1_min, S_IRUGO, show_rpm_min, NULL);
321static DEVICE_ATTR(fan1_max, S_IRUGO, show_rpm_max, NULL);
322static DEVICE_ATTR(fan1_input, S_IRUGO, show_rpm, NULL);
323static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_rpm, set_rpm);
324
325static umode_t gpio_fan_is_visible(struct kobject *kobj,
326 struct attribute *attr, int index)
327{
328 struct device *dev = container_of(kobj, struct device, kobj);
329 struct gpio_fan_data *data = dev_get_drvdata(dev);
330
331 if (index == 0 && !data->alarm)
332 return 0;
333 if (index > 0 && !data->ctrl)
334 return 0;
335
336 return attr->mode;
337}
338
339static struct attribute *gpio_fan_attributes[] = {
340 &dev_attr_fan1_alarm.attr, /* 0 */
341 &dev_attr_pwm1.attr, /* 1 */
342 &dev_attr_pwm1_enable.attr,
343 &dev_attr_pwm1_mode.attr,
344 &dev_attr_fan1_input.attr,
345 &dev_attr_fan1_target.attr,
346 &dev_attr_fan1_min.attr,
347 &dev_attr_fan1_max.attr,
348 NULL
349};
350
351static const struct attribute_group gpio_fan_group = {
352 .attrs = gpio_fan_attributes,
353 .is_visible = gpio_fan_is_visible,
354};
355
356static const struct attribute_group *gpio_fan_groups[] = {
357 &gpio_fan_group,
358 NULL
359};
360
361static int fan_ctrl_init(struct gpio_fan_data *fan_data,
362 struct gpio_fan_platform_data *pdata)
363{
364 struct platform_device *pdev = fan_data->pdev;
365 int num_ctrl = pdata->num_ctrl;
366 unsigned *ctrl = pdata->ctrl;
367 int i, err;
368
369 for (i = 0; i < num_ctrl; i++) {
370 err = devm_gpio_request(&pdev->dev, ctrl[i],
371 "GPIO fan control");
372 if (err)
373 return err;
374
375 err = gpio_direction_output(ctrl[i],
376 gpio_get_value_cansleep(ctrl[i]));
377 if (err)
378 return err;
379 }
380
381 fan_data->num_ctrl = num_ctrl;
382 fan_data->ctrl = ctrl;
383 fan_data->num_speed = pdata->num_speed;
384 fan_data->speed = pdata->speed;
385 fan_data->pwm_enable = true; /* Enable manual fan speed control. */
386 fan_data->speed_index = get_fan_speed_index(fan_data);
387 if (fan_data->speed_index < 0)
388 return fan_data->speed_index;
389
390 return 0;
391}
392
393static int gpio_fan_get_max_state(struct thermal_cooling_device *cdev,
394 unsigned long *state)
395{
396 struct gpio_fan_data *fan_data = cdev->devdata;
397
398 if (!fan_data)
399 return -EINVAL;
400
401 *state = fan_data->num_speed - 1;
402 return 0;
403}
404
405static int gpio_fan_get_cur_state(struct thermal_cooling_device *cdev,
406 unsigned long *state)
407{
408 struct gpio_fan_data *fan_data = cdev->devdata;
409
410 if (!fan_data)
411 return -EINVAL;
412
413 *state = fan_data->speed_index;
414 return 0;
415}
416
417static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev,
418 unsigned long state)
419{
420 struct gpio_fan_data *fan_data = cdev->devdata;
421
422 if (!fan_data)
423 return -EINVAL;
424
425 set_fan_speed(fan_data, state);
426 return 0;
427}
428
429static const struct thermal_cooling_device_ops gpio_fan_cool_ops = {
430 .get_max_state = gpio_fan_get_max_state,
431 .get_cur_state = gpio_fan_get_cur_state,
432 .set_cur_state = gpio_fan_set_cur_state,
433};
434
435#ifdef CONFIG_OF_GPIO
436/*
437 * Translate OpenFirmware node properties into platform_data
438 */
439static int gpio_fan_get_of_pdata(struct device *dev,
440 struct gpio_fan_platform_data *pdata)
441{
442 struct device_node *node;
443 struct gpio_fan_speed *speed;
444 unsigned *ctrl;
445 unsigned i;
446 u32 u;
447 struct property *prop;
448 const __be32 *p;
449
450 node = dev->of_node;
451
452 /* Alarm GPIO if one exists */
453 if (of_gpio_named_count(node, "alarm-gpios") > 0) {
454 struct gpio_fan_alarm *alarm;
455 int val;
456 enum of_gpio_flags flags;
457
458 alarm = devm_kzalloc(dev, sizeof(struct gpio_fan_alarm),
459 GFP_KERNEL);
460 if (!alarm)
461 return -ENOMEM;
462
463 val = of_get_named_gpio_flags(node, "alarm-gpios", 0, &flags);
464 if (val < 0)
465 return val;
466 alarm->gpio = val;
467 alarm->active_low = flags & OF_GPIO_ACTIVE_LOW;
468
469 pdata->alarm = alarm;
470 }
471
472 /* Fill GPIO pin array */
473 pdata->num_ctrl = of_gpio_count(node);
474 if (pdata->num_ctrl <= 0) {
475 if (pdata->alarm)
476 return 0;
477 dev_err(dev, "DT properties empty / missing");
478 return -ENODEV;
479 }
480 ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned),
481 GFP_KERNEL);
482 if (!ctrl)
483 return -ENOMEM;
484 for (i = 0; i < pdata->num_ctrl; i++) {
485 int val;
486
487 val = of_get_gpio(node, i);
488 if (val < 0)
489 return val;
490 ctrl[i] = val;
491 }
492 pdata->ctrl = ctrl;
493
494 /* Get number of RPM/ctrl_val pairs in speed map */
495 prop = of_find_property(node, "gpio-fan,speed-map", &i);
496 if (!prop) {
497 dev_err(dev, "gpio-fan,speed-map DT property missing");
498 return -ENODEV;
499 }
500 i = i / sizeof(u32);
501 if (i == 0 || i & 1) {
502 dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
503 return -ENODEV;
504 }
505 pdata->num_speed = i / 2;
506
507 /*
508 * Populate speed map
509 * Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
510 * this needs splitting into pairs to create gpio_fan_speed structs
511 */
512 speed = devm_kzalloc(dev,
513 pdata->num_speed * sizeof(struct gpio_fan_speed),
514 GFP_KERNEL);
515 if (!speed)
516 return -ENOMEM;
517 p = NULL;
518 for (i = 0; i < pdata->num_speed; i++) {
519 p = of_prop_next_u32(prop, p, &u);
520 if (!p)
521 return -ENODEV;
522 speed[i].rpm = u;
523 p = of_prop_next_u32(prop, p, &u);
524 if (!p)
525 return -ENODEV;
526 speed[i].ctrl_val = u;
527 }
528 pdata->speed = speed;
529
530 return 0;
531}
532
533static const struct of_device_id of_gpio_fan_match[] = {
534 { .compatible = "gpio-fan", },
535 {},
536};
537MODULE_DEVICE_TABLE(of, of_gpio_fan_match);
538#endif /* CONFIG_OF_GPIO */
539
540static int gpio_fan_probe(struct platform_device *pdev)
541{
542 int err;
543 struct gpio_fan_data *fan_data;
544 struct gpio_fan_platform_data *pdata = dev_get_platdata(&pdev->dev);
545
546 fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data),
547 GFP_KERNEL);
548 if (!fan_data)
549 return -ENOMEM;
550
551#ifdef CONFIG_OF_GPIO
552 if (!pdata) {
553 pdata = devm_kzalloc(&pdev->dev,
554 sizeof(struct gpio_fan_platform_data),
555 GFP_KERNEL);
556 if (!pdata)
557 return -ENOMEM;
558
559 err = gpio_fan_get_of_pdata(&pdev->dev, pdata);
560 if (err)
561 return err;
562 }
563#else /* CONFIG_OF_GPIO */
564 if (!pdata)
565 return -EINVAL;
566#endif /* CONFIG_OF_GPIO */
567
568 fan_data->pdev = pdev;
569 platform_set_drvdata(pdev, fan_data);
570 mutex_init(&fan_data->lock);
571
572 /* Configure alarm GPIO if available. */
573 if (pdata->alarm) {
574 err = fan_alarm_init(fan_data, pdata->alarm);
575 if (err)
576 return err;
577 }
578
579 /* Configure control GPIOs if available. */
580 if (pdata->ctrl && pdata->num_ctrl > 0) {
581 if (!pdata->speed || pdata->num_speed <= 1)
582 return -EINVAL;
583 err = fan_ctrl_init(fan_data, pdata);
584 if (err)
585 return err;
586 }
587
588 /* Make this driver part of hwmon class. */
589 fan_data->hwmon_dev =
590 devm_hwmon_device_register_with_groups(&pdev->dev,
591 "gpio_fan", fan_data,
592 gpio_fan_groups);
593 if (IS_ERR(fan_data->hwmon_dev))
594 return PTR_ERR(fan_data->hwmon_dev);
595#ifdef CONFIG_OF_GPIO
596 /* Optional cooling device register for Device tree platforms */
597 fan_data->cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
598 "gpio-fan",
599 fan_data,
600 &gpio_fan_cool_ops);
601#else /* CONFIG_OF_GPIO */
602 /* Optional cooling device register for non Device tree platforms */
603 fan_data->cdev = thermal_cooling_device_register("gpio-fan", fan_data,
604 &gpio_fan_cool_ops);
605#endif /* CONFIG_OF_GPIO */
606
607 dev_info(&pdev->dev, "GPIO fan initialized\n");
608
609 return 0;
610}
611
612static int gpio_fan_remove(struct platform_device *pdev)
613{
614 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
615
616 if (!IS_ERR(fan_data->cdev))
617 thermal_cooling_device_unregister(fan_data->cdev);
618
619 if (fan_data->ctrl)
620 set_fan_speed(fan_data, 0);
621
622 return 0;
623}
624
625static void gpio_fan_shutdown(struct platform_device *pdev)
626{
627 gpio_fan_remove(pdev);
628}
629
630#ifdef CONFIG_PM_SLEEP
631static int gpio_fan_suspend(struct device *dev)
632{
633 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
634
635 if (fan_data->ctrl) {
636 fan_data->resume_speed = fan_data->speed_index;
637 set_fan_speed(fan_data, 0);
638 }
639
640 return 0;
641}
642
643static int gpio_fan_resume(struct device *dev)
644{
645 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
646
647 if (fan_data->ctrl)
648 set_fan_speed(fan_data, fan_data->resume_speed);
649
650 return 0;
651}
652
653static SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);
654#define GPIO_FAN_PM (&gpio_fan_pm)
655#else
656#define GPIO_FAN_PM NULL
657#endif
658
659static struct platform_driver gpio_fan_driver = {
660 .probe = gpio_fan_probe,
661 .remove = gpio_fan_remove,
662 .shutdown = gpio_fan_shutdown,
663 .driver = {
664 .name = "gpio-fan",
665 .pm = GPIO_FAN_PM,
666#ifdef CONFIG_OF_GPIO
667 .of_match_table = of_match_ptr(of_gpio_fan_match),
668#endif
669 },
670};
671
672module_platform_driver(gpio_fan_driver);
673
674MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
675MODULE_DESCRIPTION("GPIO FAN driver");
676MODULE_LICENSE("GPL");
677MODULE_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/consumer.h>
33#include <linux/of.h>
34#include <linux/of_platform.h>
35#include <linux/thermal.h>
36
37struct gpio_fan_speed {
38 int rpm;
39 int ctrl_val;
40};
41
42struct gpio_fan_data {
43 struct device *dev;
44 struct device *hwmon_dev;
45 /* Cooling device if any */
46 struct thermal_cooling_device *cdev;
47 struct mutex lock; /* lock GPIOs operations. */
48 int num_gpios;
49 struct gpio_desc **gpios;
50 int num_speed;
51 struct gpio_fan_speed *speed;
52 int speed_index;
53#ifdef CONFIG_PM_SLEEP
54 int resume_speed;
55#endif
56 bool pwm_enable;
57 struct gpio_desc *alarm_gpio;
58 struct work_struct alarm_work;
59};
60
61/*
62 * Alarm GPIO.
63 */
64
65static void fan_alarm_notify(struct work_struct *ws)
66{
67 struct gpio_fan_data *fan_data =
68 container_of(ws, struct gpio_fan_data, alarm_work);
69
70 sysfs_notify(&fan_data->dev->kobj, NULL, "fan1_alarm");
71 kobject_uevent(&fan_data->dev->kobj, KOBJ_CHANGE);
72}
73
74static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
75{
76 struct gpio_fan_data *fan_data = dev_id;
77
78 schedule_work(&fan_data->alarm_work);
79
80 return IRQ_NONE;
81}
82
83static ssize_t fan1_alarm_show(struct device *dev,
84 struct device_attribute *attr, char *buf)
85{
86 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
87
88 return sprintf(buf, "%d\n",
89 gpiod_get_value_cansleep(fan_data->alarm_gpio));
90}
91
92static DEVICE_ATTR_RO(fan1_alarm);
93
94static int fan_alarm_init(struct gpio_fan_data *fan_data)
95{
96 int alarm_irq;
97 struct device *dev = fan_data->dev;
98
99 /*
100 * If the alarm GPIO don't support interrupts, just leave
101 * without initializing the fail notification support.
102 */
103 alarm_irq = gpiod_to_irq(fan_data->alarm_gpio);
104 if (alarm_irq <= 0)
105 return 0;
106
107 INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
108 irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
109 return devm_request_irq(dev, alarm_irq, fan_alarm_irq_handler,
110 IRQF_SHARED, "GPIO fan alarm", fan_data);
111}
112
113/*
114 * Control GPIOs.
115 */
116
117/* Must be called with fan_data->lock held, except during initialization. */
118static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
119{
120 int i;
121
122 for (i = 0; i < fan_data->num_gpios; i++)
123 gpiod_set_value_cansleep(fan_data->gpios[i],
124 (ctrl_val >> i) & 1);
125}
126
127static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
128{
129 int i;
130 int ctrl_val = 0;
131
132 for (i = 0; i < fan_data->num_gpios; i++) {
133 int value;
134
135 value = gpiod_get_value_cansleep(fan_data->gpios[i]);
136 ctrl_val |= (value << i);
137 }
138 return ctrl_val;
139}
140
141/* Must be called with fan_data->lock held, except during initialization. */
142static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
143{
144 if (fan_data->speed_index == speed_index)
145 return;
146
147 __set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
148 fan_data->speed_index = speed_index;
149}
150
151static int get_fan_speed_index(struct gpio_fan_data *fan_data)
152{
153 int ctrl_val = __get_fan_ctrl(fan_data);
154 int i;
155
156 for (i = 0; i < fan_data->num_speed; i++)
157 if (fan_data->speed[i].ctrl_val == ctrl_val)
158 return i;
159
160 dev_warn(fan_data->dev,
161 "missing speed array entry for GPIO value 0x%x\n", ctrl_val);
162
163 return -ENODEV;
164}
165
166static int rpm_to_speed_index(struct gpio_fan_data *fan_data, unsigned long rpm)
167{
168 struct gpio_fan_speed *speed = fan_data->speed;
169 int i;
170
171 for (i = 0; i < fan_data->num_speed; i++)
172 if (speed[i].rpm >= rpm)
173 return i;
174
175 return fan_data->num_speed - 1;
176}
177
178static ssize_t pwm1_show(struct device *dev, struct device_attribute *attr,
179 char *buf)
180{
181 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
182 u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);
183
184 return sprintf(buf, "%d\n", pwm);
185}
186
187static ssize_t pwm1_store(struct device *dev, struct device_attribute *attr,
188 const char *buf, size_t count)
189{
190 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
191 unsigned long pwm;
192 int speed_index;
193 int ret = count;
194
195 if (kstrtoul(buf, 10, &pwm) || pwm > 255)
196 return -EINVAL;
197
198 mutex_lock(&fan_data->lock);
199
200 if (!fan_data->pwm_enable) {
201 ret = -EPERM;
202 goto exit_unlock;
203 }
204
205 speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
206 set_fan_speed(fan_data, speed_index);
207
208exit_unlock:
209 mutex_unlock(&fan_data->lock);
210
211 return ret;
212}
213
214static ssize_t pwm1_enable_show(struct device *dev,
215 struct device_attribute *attr, char *buf)
216{
217 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
218
219 return sprintf(buf, "%d\n", fan_data->pwm_enable);
220}
221
222static ssize_t pwm1_enable_store(struct device *dev,
223 struct device_attribute *attr,
224 const char *buf, size_t count)
225{
226 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
227 unsigned long val;
228
229 if (kstrtoul(buf, 10, &val) || val > 1)
230 return -EINVAL;
231
232 if (fan_data->pwm_enable == val)
233 return count;
234
235 mutex_lock(&fan_data->lock);
236
237 fan_data->pwm_enable = val;
238
239 /* Disable manual control mode: set fan at full speed. */
240 if (val == 0)
241 set_fan_speed(fan_data, fan_data->num_speed - 1);
242
243 mutex_unlock(&fan_data->lock);
244
245 return count;
246}
247
248static ssize_t pwm1_mode_show(struct device *dev,
249 struct device_attribute *attr, char *buf)
250{
251 return sprintf(buf, "0\n");
252}
253
254static ssize_t fan1_min_show(struct device *dev,
255 struct device_attribute *attr, char *buf)
256{
257 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
258
259 return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
260}
261
262static ssize_t fan1_max_show(struct device *dev,
263 struct device_attribute *attr, char *buf)
264{
265 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
266
267 return sprintf(buf, "%d\n",
268 fan_data->speed[fan_data->num_speed - 1].rpm);
269}
270
271static ssize_t fan1_input_show(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", fan_data->speed[fan_data->speed_index].rpm);
277}
278
279static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
280 const char *buf, size_t count)
281{
282 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
283 unsigned long rpm;
284 int ret = count;
285
286 if (kstrtoul(buf, 10, &rpm))
287 return -EINVAL;
288
289 mutex_lock(&fan_data->lock);
290
291 if (!fan_data->pwm_enable) {
292 ret = -EPERM;
293 goto exit_unlock;
294 }
295
296 set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
297
298exit_unlock:
299 mutex_unlock(&fan_data->lock);
300
301 return ret;
302}
303
304static DEVICE_ATTR_RW(pwm1);
305static DEVICE_ATTR_RW(pwm1_enable);
306static DEVICE_ATTR_RO(pwm1_mode);
307static DEVICE_ATTR_RO(fan1_min);
308static DEVICE_ATTR_RO(fan1_max);
309static DEVICE_ATTR_RO(fan1_input);
310static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, fan1_input_show, set_rpm);
311
312static umode_t gpio_fan_is_visible(struct kobject *kobj,
313 struct attribute *attr, int index)
314{
315 struct device *dev = container_of(kobj, struct device, kobj);
316 struct gpio_fan_data *data = dev_get_drvdata(dev);
317
318 if (index == 0 && !data->alarm_gpio)
319 return 0;
320 if (index > 0 && !data->gpios)
321 return 0;
322
323 return attr->mode;
324}
325
326static struct attribute *gpio_fan_attributes[] = {
327 &dev_attr_fan1_alarm.attr, /* 0 */
328 &dev_attr_pwm1.attr, /* 1 */
329 &dev_attr_pwm1_enable.attr,
330 &dev_attr_pwm1_mode.attr,
331 &dev_attr_fan1_input.attr,
332 &dev_attr_fan1_target.attr,
333 &dev_attr_fan1_min.attr,
334 &dev_attr_fan1_max.attr,
335 NULL
336};
337
338static const struct attribute_group gpio_fan_group = {
339 .attrs = gpio_fan_attributes,
340 .is_visible = gpio_fan_is_visible,
341};
342
343static const struct attribute_group *gpio_fan_groups[] = {
344 &gpio_fan_group,
345 NULL
346};
347
348static int fan_ctrl_init(struct gpio_fan_data *fan_data)
349{
350 int num_gpios = fan_data->num_gpios;
351 struct gpio_desc **gpios = fan_data->gpios;
352 int i, err;
353
354 for (i = 0; i < num_gpios; i++) {
355 /*
356 * The GPIO descriptors were retrieved with GPIOD_ASIS so here
357 * we set the GPIO into output mode, carefully preserving the
358 * current value by setting it to whatever it is already set
359 * (no surprise changes in default fan speed).
360 */
361 err = gpiod_direction_output(gpios[i],
362 gpiod_get_value_cansleep(gpios[i]));
363 if (err)
364 return err;
365 }
366
367 fan_data->pwm_enable = true; /* Enable manual fan speed control. */
368 fan_data->speed_index = get_fan_speed_index(fan_data);
369 if (fan_data->speed_index < 0)
370 return fan_data->speed_index;
371
372 return 0;
373}
374
375static int gpio_fan_get_max_state(struct thermal_cooling_device *cdev,
376 unsigned long *state)
377{
378 struct gpio_fan_data *fan_data = cdev->devdata;
379
380 if (!fan_data)
381 return -EINVAL;
382
383 *state = fan_data->num_speed - 1;
384 return 0;
385}
386
387static int gpio_fan_get_cur_state(struct thermal_cooling_device *cdev,
388 unsigned long *state)
389{
390 struct gpio_fan_data *fan_data = cdev->devdata;
391
392 if (!fan_data)
393 return -EINVAL;
394
395 *state = fan_data->speed_index;
396 return 0;
397}
398
399static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev,
400 unsigned long state)
401{
402 struct gpio_fan_data *fan_data = cdev->devdata;
403
404 if (!fan_data)
405 return -EINVAL;
406
407 set_fan_speed(fan_data, state);
408 return 0;
409}
410
411static const struct thermal_cooling_device_ops gpio_fan_cool_ops = {
412 .get_max_state = gpio_fan_get_max_state,
413 .get_cur_state = gpio_fan_get_cur_state,
414 .set_cur_state = gpio_fan_set_cur_state,
415};
416
417/*
418 * Translate OpenFirmware node properties into platform_data
419 */
420static int gpio_fan_get_of_data(struct gpio_fan_data *fan_data)
421{
422 struct gpio_fan_speed *speed;
423 struct device *dev = fan_data->dev;
424 struct device_node *np = dev->of_node;
425 struct gpio_desc **gpios;
426 unsigned i;
427 u32 u;
428 struct property *prop;
429 const __be32 *p;
430
431 /* Alarm GPIO if one exists */
432 fan_data->alarm_gpio = devm_gpiod_get_optional(dev, "alarm", GPIOD_IN);
433 if (IS_ERR(fan_data->alarm_gpio))
434 return PTR_ERR(fan_data->alarm_gpio);
435
436 /* Fill GPIO pin array */
437 fan_data->num_gpios = gpiod_count(dev, NULL);
438 if (fan_data->num_gpios <= 0) {
439 if (fan_data->alarm_gpio)
440 return 0;
441 dev_err(dev, "DT properties empty / missing");
442 return -ENODEV;
443 }
444 gpios = devm_kzalloc(dev,
445 fan_data->num_gpios * sizeof(struct gpio_desc *),
446 GFP_KERNEL);
447 if (!gpios)
448 return -ENOMEM;
449 for (i = 0; i < fan_data->num_gpios; i++) {
450 gpios[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
451 if (IS_ERR(gpios[i]))
452 return PTR_ERR(gpios[i]);
453 }
454 fan_data->gpios = gpios;
455
456 /* Get number of RPM/ctrl_val pairs in speed map */
457 prop = of_find_property(np, "gpio-fan,speed-map", &i);
458 if (!prop) {
459 dev_err(dev, "gpio-fan,speed-map DT property missing");
460 return -ENODEV;
461 }
462 i = i / sizeof(u32);
463 if (i == 0 || i & 1) {
464 dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
465 return -ENODEV;
466 }
467 fan_data->num_speed = i / 2;
468
469 /*
470 * Populate speed map
471 * Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
472 * this needs splitting into pairs to create gpio_fan_speed structs
473 */
474 speed = devm_kzalloc(dev,
475 fan_data->num_speed * sizeof(struct gpio_fan_speed),
476 GFP_KERNEL);
477 if (!speed)
478 return -ENOMEM;
479 p = NULL;
480 for (i = 0; i < fan_data->num_speed; i++) {
481 p = of_prop_next_u32(prop, p, &u);
482 if (!p)
483 return -ENODEV;
484 speed[i].rpm = u;
485 p = of_prop_next_u32(prop, p, &u);
486 if (!p)
487 return -ENODEV;
488 speed[i].ctrl_val = u;
489 }
490 fan_data->speed = speed;
491
492 return 0;
493}
494
495static const struct of_device_id of_gpio_fan_match[] = {
496 { .compatible = "gpio-fan", },
497 {},
498};
499MODULE_DEVICE_TABLE(of, of_gpio_fan_match);
500
501static int gpio_fan_probe(struct platform_device *pdev)
502{
503 int err;
504 struct gpio_fan_data *fan_data;
505 struct device *dev = &pdev->dev;
506 struct device_node *np = dev->of_node;
507
508 fan_data = devm_kzalloc(dev, sizeof(struct gpio_fan_data),
509 GFP_KERNEL);
510 if (!fan_data)
511 return -ENOMEM;
512
513 fan_data->dev = dev;
514 err = gpio_fan_get_of_data(fan_data);
515 if (err)
516 return err;
517
518 platform_set_drvdata(pdev, fan_data);
519 mutex_init(&fan_data->lock);
520
521 /* Configure alarm GPIO if available. */
522 if (fan_data->alarm_gpio) {
523 err = fan_alarm_init(fan_data);
524 if (err)
525 return err;
526 }
527
528 /* Configure control GPIOs if available. */
529 if (fan_data->gpios && fan_data->num_gpios > 0) {
530 if (!fan_data->speed || fan_data->num_speed <= 1)
531 return -EINVAL;
532 err = fan_ctrl_init(fan_data);
533 if (err)
534 return err;
535 }
536
537 /* Make this driver part of hwmon class. */
538 fan_data->hwmon_dev =
539 devm_hwmon_device_register_with_groups(dev,
540 "gpio_fan", fan_data,
541 gpio_fan_groups);
542 if (IS_ERR(fan_data->hwmon_dev))
543 return PTR_ERR(fan_data->hwmon_dev);
544
545 /* Optional cooling device register for Device tree platforms */
546 fan_data->cdev = thermal_of_cooling_device_register(np,
547 "gpio-fan",
548 fan_data,
549 &gpio_fan_cool_ops);
550
551 dev_info(dev, "GPIO fan initialized\n");
552
553 return 0;
554}
555
556static int gpio_fan_remove(struct platform_device *pdev)
557{
558 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
559
560 if (!IS_ERR(fan_data->cdev))
561 thermal_cooling_device_unregister(fan_data->cdev);
562
563 if (fan_data->gpios)
564 set_fan_speed(fan_data, 0);
565
566 return 0;
567}
568
569static void gpio_fan_shutdown(struct platform_device *pdev)
570{
571 gpio_fan_remove(pdev);
572}
573
574#ifdef CONFIG_PM_SLEEP
575static int gpio_fan_suspend(struct device *dev)
576{
577 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
578
579 if (fan_data->gpios) {
580 fan_data->resume_speed = fan_data->speed_index;
581 set_fan_speed(fan_data, 0);
582 }
583
584 return 0;
585}
586
587static int gpio_fan_resume(struct device *dev)
588{
589 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
590
591 if (fan_data->gpios)
592 set_fan_speed(fan_data, fan_data->resume_speed);
593
594 return 0;
595}
596
597static SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);
598#define GPIO_FAN_PM (&gpio_fan_pm)
599#else
600#define GPIO_FAN_PM NULL
601#endif
602
603static struct platform_driver gpio_fan_driver = {
604 .probe = gpio_fan_probe,
605 .remove = gpio_fan_remove,
606 .shutdown = gpio_fan_shutdown,
607 .driver = {
608 .name = "gpio-fan",
609 .pm = GPIO_FAN_PM,
610 .of_match_table = of_match_ptr(of_gpio_fan_match),
611 },
612};
613
614module_platform_driver(gpio_fan_driver);
615
616MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
617MODULE_DESCRIPTION("GPIO FAN driver");
618MODULE_LICENSE("GPL");
619MODULE_ALIAS("platform:gpio-fan");