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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
39 struct 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
62 static 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
71 static 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
80 static 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
93 static DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL);
94
95 static 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. */
132 static 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
140 static 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. */
155 static 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
164 static 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
179 static 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
191 static 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
200 static 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
221 exit_unlock:
222 mutex_unlock(&fan_data->lock);
223
224 return ret;
225 }
226
227 static 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
235 static 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
260 static ssize_t show_pwm_mode(struct device *dev,
261 struct device_attribute *attr, char *buf)
262 {
263 return sprintf(buf, "0\n");
264 }
265
266 static 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
274 static 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
283 static 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
291 static 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
310 exit_unlock:
311 mutex_unlock(&fan_data->lock);
312
313 return ret;
314 }
315
316 static DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm);
317 static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
318 show_pwm_enable, set_pwm_enable);
319 static DEVICE_ATTR(pwm1_mode, S_IRUGO, show_pwm_mode, NULL);
320 static DEVICE_ATTR(fan1_min, S_IRUGO, show_rpm_min, NULL);
321 static DEVICE_ATTR(fan1_max, S_IRUGO, show_rpm_max, NULL);
322 static DEVICE_ATTR(fan1_input, S_IRUGO, show_rpm, NULL);
323 static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_rpm, set_rpm);
324
325 static 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
339 static 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
351 static const struct attribute_group gpio_fan_group = {
352 .attrs = gpio_fan_attributes,
353 .is_visible = gpio_fan_is_visible,
354 };
355
356 static const struct attribute_group *gpio_fan_groups[] = {
357 &gpio_fan_group,
358 NULL
359 };
360
361 static 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
393 static 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
405 static 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 int r;
410
411 if (!fan_data)
412 return -EINVAL;
413
414 r = get_fan_speed_index(fan_data);
415 if (r < 0)
416 return r;
417
418 *state = r;
419 return 0;
420 }
421
422 static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev,
423 unsigned long state)
424 {
425 struct gpio_fan_data *fan_data = cdev->devdata;
426
427 if (!fan_data)
428 return -EINVAL;
429
430 set_fan_speed(fan_data, state);
431 return 0;
432 }
433
434 static const struct thermal_cooling_device_ops gpio_fan_cool_ops = {
435 .get_max_state = gpio_fan_get_max_state,
436 .get_cur_state = gpio_fan_get_cur_state,
437 .set_cur_state = gpio_fan_set_cur_state,
438 };
439
440 #ifdef CONFIG_OF_GPIO
441 /*
442 * Translate OpenFirmware node properties into platform_data
443 */
444 static int gpio_fan_get_of_pdata(struct device *dev,
445 struct gpio_fan_platform_data *pdata)
446 {
447 struct device_node *node;
448 struct gpio_fan_speed *speed;
449 unsigned *ctrl;
450 unsigned i;
451 u32 u;
452 struct property *prop;
453 const __be32 *p;
454
455 node = dev->of_node;
456
457 /* Alarm GPIO if one exists */
458 if (of_gpio_named_count(node, "alarm-gpios") > 0) {
459 struct gpio_fan_alarm *alarm;
460 int val;
461 enum of_gpio_flags flags;
462
463 alarm = devm_kzalloc(dev, sizeof(struct gpio_fan_alarm),
464 GFP_KERNEL);
465 if (!alarm)
466 return -ENOMEM;
467
468 val = of_get_named_gpio_flags(node, "alarm-gpios", 0, &flags);
469 if (val < 0)
470 return val;
471 alarm->gpio = val;
472 alarm->active_low = flags & OF_GPIO_ACTIVE_LOW;
473
474 pdata->alarm = alarm;
475 }
476
477 /* Fill GPIO pin array */
478 pdata->num_ctrl = of_gpio_count(node);
479 if (pdata->num_ctrl <= 0) {
480 if (pdata->alarm)
481 return 0;
482 dev_err(dev, "DT properties empty / missing");
483 return -ENODEV;
484 }
485 ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned),
486 GFP_KERNEL);
487 if (!ctrl)
488 return -ENOMEM;
489 for (i = 0; i < pdata->num_ctrl; i++) {
490 int val;
491
492 val = of_get_gpio(node, i);
493 if (val < 0)
494 return val;
495 ctrl[i] = val;
496 }
497 pdata->ctrl = ctrl;
498
499 /* Get number of RPM/ctrl_val pairs in speed map */
500 prop = of_find_property(node, "gpio-fan,speed-map", &i);
501 if (!prop) {
502 dev_err(dev, "gpio-fan,speed-map DT property missing");
503 return -ENODEV;
504 }
505 i = i / sizeof(u32);
506 if (i == 0 || i & 1) {
507 dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
508 return -ENODEV;
509 }
510 pdata->num_speed = i / 2;
511
512 /*
513 * Populate speed map
514 * Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
515 * this needs splitting into pairs to create gpio_fan_speed structs
516 */
517 speed = devm_kzalloc(dev,
518 pdata->num_speed * sizeof(struct gpio_fan_speed),
519 GFP_KERNEL);
520 if (!speed)
521 return -ENOMEM;
522 p = NULL;
523 for (i = 0; i < pdata->num_speed; i++) {
524 p = of_prop_next_u32(prop, p, &u);
525 if (!p)
526 return -ENODEV;
527 speed[i].rpm = u;
528 p = of_prop_next_u32(prop, p, &u);
529 if (!p)
530 return -ENODEV;
531 speed[i].ctrl_val = u;
532 }
533 pdata->speed = speed;
534
535 return 0;
536 }
537
538 static const struct of_device_id of_gpio_fan_match[] = {
539 { .compatible = "gpio-fan", },
540 {},
541 };
542 MODULE_DEVICE_TABLE(of, of_gpio_fan_match);
543 #endif /* CONFIG_OF_GPIO */
544
545 static int gpio_fan_probe(struct platform_device *pdev)
546 {
547 int err;
548 struct gpio_fan_data *fan_data;
549 struct gpio_fan_platform_data *pdata = dev_get_platdata(&pdev->dev);
550
551 fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data),
552 GFP_KERNEL);
553 if (!fan_data)
554 return -ENOMEM;
555
556 #ifdef CONFIG_OF_GPIO
557 if (!pdata) {
558 pdata = devm_kzalloc(&pdev->dev,
559 sizeof(struct gpio_fan_platform_data),
560 GFP_KERNEL);
561 if (!pdata)
562 return -ENOMEM;
563
564 err = gpio_fan_get_of_pdata(&pdev->dev, pdata);
565 if (err)
566 return err;
567 }
568 #else /* CONFIG_OF_GPIO */
569 if (!pdata)
570 return -EINVAL;
571 #endif /* CONFIG_OF_GPIO */
572
573 fan_data->pdev = pdev;
574 platform_set_drvdata(pdev, fan_data);
575 mutex_init(&fan_data->lock);
576
577 /* Configure alarm GPIO if available. */
578 if (pdata->alarm) {
579 err = fan_alarm_init(fan_data, pdata->alarm);
580 if (err)
581 return err;
582 }
583
584 /* Configure control GPIOs if available. */
585 if (pdata->ctrl && pdata->num_ctrl > 0) {
586 if (!pdata->speed || pdata->num_speed <= 1)
587 return -EINVAL;
588 err = fan_ctrl_init(fan_data, pdata);
589 if (err)
590 return err;
591 }
592
593 /* Make this driver part of hwmon class. */
594 fan_data->hwmon_dev =
595 devm_hwmon_device_register_with_groups(&pdev->dev,
596 "gpio_fan", fan_data,
597 gpio_fan_groups);
598 if (IS_ERR(fan_data->hwmon_dev))
599 return PTR_ERR(fan_data->hwmon_dev);
600 #ifdef CONFIG_OF_GPIO
601 /* Optional cooling device register for Device tree platforms */
602 fan_data->cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
603 "gpio-fan",
604 fan_data,
605 &gpio_fan_cool_ops);
606 #else /* CONFIG_OF_GPIO */
607 /* Optional cooling device register for non Device tree platforms */
608 fan_data->cdev = thermal_cooling_device_register("gpio-fan", fan_data,
609 &gpio_fan_cool_ops);
610 #endif /* CONFIG_OF_GPIO */
611
612 dev_info(&pdev->dev, "GPIO fan initialized\n");
613
614 return 0;
615 }
616
617 static int gpio_fan_remove(struct platform_device *pdev)
618 {
619 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
620
621 if (!IS_ERR(fan_data->cdev))
622 thermal_cooling_device_unregister(fan_data->cdev);
623
624 if (fan_data->ctrl)
625 set_fan_speed(fan_data, 0);
626
627 return 0;
628 }
629
630 static void gpio_fan_shutdown(struct platform_device *pdev)
631 {
632 gpio_fan_remove(pdev);
633 }
634
635 #ifdef CONFIG_PM_SLEEP
636 static int gpio_fan_suspend(struct device *dev)
637 {
638 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
639
640 if (fan_data->ctrl) {
641 fan_data->resume_speed = fan_data->speed_index;
642 set_fan_speed(fan_data, 0);
643 }
644
645 return 0;
646 }
647
648 static int gpio_fan_resume(struct device *dev)
649 {
650 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
651
652 if (fan_data->ctrl)
653 set_fan_speed(fan_data, fan_data->resume_speed);
654
655 return 0;
656 }
657
658 static SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);
659 #define GPIO_FAN_PM (&gpio_fan_pm)
660 #else
661 #define GPIO_FAN_PM NULL
662 #endif
663
664 static struct platform_driver gpio_fan_driver = {
665 .probe = gpio_fan_probe,
666 .remove = gpio_fan_remove,
667 .shutdown = gpio_fan_shutdown,
668 .driver = {
669 .name = "gpio-fan",
670 .pm = GPIO_FAN_PM,
671 #ifdef CONFIG_OF_GPIO
672 .of_match_table = of_match_ptr(of_gpio_fan_match),
673 #endif
674 },
675 };
676
677 module_platform_driver(gpio_fan_driver);
678
679 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
680 MODULE_DESCRIPTION("GPIO FAN driver");
681 MODULE_LICENSE("GPL");
682 MODULE_ALIAS("platform:gpio-fan");