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/pm.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/regulator/consumer.h>
26 #include <linux/thermal.h>
27
28 struct gpio_fan_speed {
29 int rpm;
30 int ctrl_val;
31 };
32
33 struct gpio_fan_data {
34 struct device *dev;
35 struct device *hwmon_dev;
36 /* Cooling device if any */
37 struct thermal_cooling_device *cdev;
38 struct mutex lock; /* lock GPIOs operations. */
39 int num_gpios;
40 struct gpio_desc **gpios;
41 int num_speed;
42 struct gpio_fan_speed *speed;
43 int speed_index;
44 int resume_speed;
45 bool pwm_enable;
46 struct gpio_desc *alarm_gpio;
47 struct work_struct alarm_work;
48 struct regulator *supply;
49 };
50
51 /*
52 * Alarm GPIO.
53 */
54
fan_alarm_notify(struct work_struct * ws)55 static void fan_alarm_notify(struct work_struct *ws)
56 {
57 struct gpio_fan_data *fan_data =
58 container_of(ws, struct gpio_fan_data, alarm_work);
59
60 sysfs_notify(&fan_data->hwmon_dev->kobj, NULL, "fan1_alarm");
61 kobject_uevent(&fan_data->hwmon_dev->kobj, KOBJ_CHANGE);
62 }
63
fan_alarm_irq_handler(int irq,void * dev_id)64 static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
65 {
66 struct gpio_fan_data *fan_data = dev_id;
67
68 schedule_work(&fan_data->alarm_work);
69
70 return IRQ_NONE;
71 }
72
fan1_alarm_show(struct device * dev,struct device_attribute * attr,char * buf)73 static ssize_t fan1_alarm_show(struct device *dev,
74 struct device_attribute *attr, char *buf)
75 {
76 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
77
78 return sprintf(buf, "%d\n",
79 gpiod_get_value_cansleep(fan_data->alarm_gpio));
80 }
81
82 static DEVICE_ATTR_RO(fan1_alarm);
83
fan_alarm_init(struct gpio_fan_data * fan_data)84 static int fan_alarm_init(struct gpio_fan_data *fan_data)
85 {
86 int alarm_irq;
87 struct device *dev = fan_data->dev;
88
89 /*
90 * If the alarm GPIO don't support interrupts, just leave
91 * without initializing the fail notification support.
92 */
93 alarm_irq = gpiod_to_irq(fan_data->alarm_gpio);
94 if (alarm_irq <= 0)
95 return 0;
96
97 INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
98 irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
99 return devm_request_irq(dev, alarm_irq, fan_alarm_irq_handler,
100 IRQF_SHARED, "GPIO fan alarm", fan_data);
101 }
102
103 /*
104 * Control GPIOs.
105 */
106
107 /* Must be called with fan_data->lock held, except during initialization. */
__set_fan_ctrl(struct gpio_fan_data * fan_data,int ctrl_val)108 static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
109 {
110 int i;
111
112 for (i = 0; i < fan_data->num_gpios; i++)
113 gpiod_set_value_cansleep(fan_data->gpios[i],
114 (ctrl_val >> i) & 1);
115 }
116
__get_fan_ctrl(struct gpio_fan_data * fan_data)117 static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
118 {
119 int i;
120 int ctrl_val = 0;
121
122 for (i = 0; i < fan_data->num_gpios; i++) {
123 int value;
124
125 value = gpiod_get_value_cansleep(fan_data->gpios[i]);
126 ctrl_val |= (value << i);
127 }
128 return ctrl_val;
129 }
130
131 /* Must be called with fan_data->lock held, except during initialization. */
set_fan_speed(struct gpio_fan_data * fan_data,int speed_index)132 static int set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
133 {
134 if (fan_data->speed_index == speed_index)
135 return 0;
136
137 if (fan_data->speed_index == 0 && speed_index > 0) {
138 int ret;
139
140 ret = pm_runtime_resume_and_get(fan_data->dev);
141 if (ret < 0)
142 return ret;
143 }
144
145 __set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
146
147 if (fan_data->speed_index > 0 && speed_index == 0) {
148 int ret;
149
150 ret = pm_runtime_put_sync(fan_data->dev);
151 if (ret < 0)
152 return ret;
153 }
154
155 fan_data->speed_index = speed_index;
156
157 return 0;
158 }
159
get_fan_speed_index(struct gpio_fan_data * fan_data)160 static int get_fan_speed_index(struct gpio_fan_data *fan_data)
161 {
162 int ctrl_val = __get_fan_ctrl(fan_data);
163 int i;
164
165 for (i = 0; i < fan_data->num_speed; i++)
166 if (fan_data->speed[i].ctrl_val == ctrl_val)
167 return i;
168
169 dev_warn(fan_data->dev,
170 "missing speed array entry for GPIO value 0x%x\n", ctrl_val);
171
172 return -ENODEV;
173 }
174
rpm_to_speed_index(struct gpio_fan_data * fan_data,unsigned long rpm)175 static int rpm_to_speed_index(struct gpio_fan_data *fan_data, unsigned long rpm)
176 {
177 struct gpio_fan_speed *speed = fan_data->speed;
178 int i;
179
180 for (i = 0; i < fan_data->num_speed; i++)
181 if (speed[i].rpm >= rpm)
182 return i;
183
184 return fan_data->num_speed - 1;
185 }
186
pwm1_show(struct device * dev,struct device_attribute * attr,char * buf)187 static ssize_t pwm1_show(struct device *dev, struct device_attribute *attr,
188 char *buf)
189 {
190 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
191 u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);
192
193 return sprintf(buf, "%d\n", pwm);
194 }
195
pwm1_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)196 static ssize_t pwm1_store(struct device *dev, struct device_attribute *attr,
197 const char *buf, size_t count)
198 {
199 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
200 unsigned long pwm;
201 int speed_index;
202 int ret;
203
204 if (kstrtoul(buf, 10, &pwm) || pwm > 255)
205 return -EINVAL;
206
207 mutex_lock(&fan_data->lock);
208
209 if (!fan_data->pwm_enable) {
210 ret = -EPERM;
211 goto exit_unlock;
212 }
213
214 speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
215 ret = set_fan_speed(fan_data, speed_index);
216
217 exit_unlock:
218 mutex_unlock(&fan_data->lock);
219
220 return ret ? ret : count;
221 }
222
pwm1_enable_show(struct device * dev,struct device_attribute * attr,char * buf)223 static ssize_t pwm1_enable_show(struct device *dev,
224 struct device_attribute *attr, char *buf)
225 {
226 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
227
228 return sprintf(buf, "%d\n", fan_data->pwm_enable);
229 }
230
pwm1_enable_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)231 static ssize_t pwm1_enable_store(struct device *dev,
232 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 int ret = 0;
238
239 if (kstrtoul(buf, 10, &val) || val > 1)
240 return -EINVAL;
241
242 if (fan_data->pwm_enable == val)
243 return count;
244
245 mutex_lock(&fan_data->lock);
246
247 fan_data->pwm_enable = val;
248
249 /* Disable manual control mode: set fan at full speed. */
250 if (val == 0)
251 ret = set_fan_speed(fan_data, fan_data->num_speed - 1);
252
253 mutex_unlock(&fan_data->lock);
254
255 return ret ? ret : count;
256 }
257
pwm1_mode_show(struct device * dev,struct device_attribute * attr,char * buf)258 static ssize_t pwm1_mode_show(struct device *dev,
259 struct device_attribute *attr, char *buf)
260 {
261 return sprintf(buf, "0\n");
262 }
263
fan1_min_show(struct device * dev,struct device_attribute * attr,char * buf)264 static ssize_t fan1_min_show(struct device *dev,
265 struct device_attribute *attr, char *buf)
266 {
267 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
268
269 return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
270 }
271
fan1_max_show(struct device * dev,struct device_attribute * attr,char * buf)272 static ssize_t fan1_max_show(struct device *dev,
273 struct device_attribute *attr, char *buf)
274 {
275 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
276
277 return sprintf(buf, "%d\n",
278 fan_data->speed[fan_data->num_speed - 1].rpm);
279 }
280
fan1_input_show(struct device * dev,struct device_attribute * attr,char * buf)281 static ssize_t fan1_input_show(struct device *dev,
282 struct device_attribute *attr, char *buf)
283 {
284 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
285
286 return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
287 }
288
set_rpm(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)289 static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
290 const char *buf, size_t count)
291 {
292 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
293 unsigned long rpm;
294 int ret = count;
295
296 if (kstrtoul(buf, 10, &rpm))
297 return -EINVAL;
298
299 mutex_lock(&fan_data->lock);
300
301 if (!fan_data->pwm_enable) {
302 ret = -EPERM;
303 goto exit_unlock;
304 }
305
306 ret = set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
307
308 exit_unlock:
309 mutex_unlock(&fan_data->lock);
310
311 return ret;
312 }
313
314 static DEVICE_ATTR_RW(pwm1);
315 static DEVICE_ATTR_RW(pwm1_enable);
316 static DEVICE_ATTR_RO(pwm1_mode);
317 static DEVICE_ATTR_RO(fan1_min);
318 static DEVICE_ATTR_RO(fan1_max);
319 static DEVICE_ATTR_RO(fan1_input);
320 static DEVICE_ATTR(fan1_target, 0644, fan1_input_show, set_rpm);
321
gpio_fan_is_visible(struct kobject * kobj,struct attribute * attr,int index)322 static umode_t gpio_fan_is_visible(struct kobject *kobj,
323 struct attribute *attr, int index)
324 {
325 struct device *dev = kobj_to_dev(kobj);
326 struct gpio_fan_data *data = dev_get_drvdata(dev);
327
328 if (index == 0 && !data->alarm_gpio)
329 return 0;
330 if (index > 0 && !data->gpios)
331 return 0;
332
333 return attr->mode;
334 }
335
336 static 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
348 static const struct attribute_group gpio_fan_group = {
349 .attrs = gpio_fan_attributes,
350 .is_visible = gpio_fan_is_visible,
351 };
352
353 static const struct attribute_group *gpio_fan_groups[] = {
354 &gpio_fan_group,
355 NULL
356 };
357
fan_ctrl_init(struct gpio_fan_data * fan_data)358 static int fan_ctrl_init(struct gpio_fan_data *fan_data)
359 {
360 int num_gpios = fan_data->num_gpios;
361 struct gpio_desc **gpios = fan_data->gpios;
362 int i, err;
363
364 for (i = 0; i < num_gpios; i++) {
365 /*
366 * The GPIO descriptors were retrieved with GPIOD_ASIS so here
367 * we set the GPIO into output mode, carefully preserving the
368 * current value by setting it to whatever it is already set
369 * (no surprise changes in default fan speed).
370 */
371 err = gpiod_direction_output(gpios[i],
372 gpiod_get_value_cansleep(gpios[i]));
373 if (err)
374 return err;
375 }
376
377 fan_data->pwm_enable = true; /* Enable manual fan speed control. */
378 fan_data->speed_index = get_fan_speed_index(fan_data);
379 if (fan_data->speed_index < 0)
380 return fan_data->speed_index;
381
382 return 0;
383 }
384
gpio_fan_get_max_state(struct thermal_cooling_device * cdev,unsigned long * state)385 static int gpio_fan_get_max_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 *state = fan_data->num_speed - 1;
394 return 0;
395 }
396
gpio_fan_get_cur_state(struct thermal_cooling_device * cdev,unsigned long * state)397 static int gpio_fan_get_cur_state(struct thermal_cooling_device *cdev,
398 unsigned long *state)
399 {
400 struct gpio_fan_data *fan_data = cdev->devdata;
401
402 if (!fan_data)
403 return -EINVAL;
404
405 *state = fan_data->speed_index;
406 return 0;
407 }
408
gpio_fan_set_cur_state(struct thermal_cooling_device * cdev,unsigned long state)409 static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev,
410 unsigned long state)
411 {
412 struct gpio_fan_data *fan_data = cdev->devdata;
413 int ret;
414
415 if (!fan_data)
416 return -EINVAL;
417
418 if (state >= fan_data->num_speed)
419 return -EINVAL;
420
421 mutex_lock(&fan_data->lock);
422
423 ret = set_fan_speed(fan_data, state);
424
425 mutex_unlock(&fan_data->lock);
426
427 return ret;
428 }
429
430 static const struct thermal_cooling_device_ops gpio_fan_cool_ops = {
431 .get_max_state = gpio_fan_get_max_state,
432 .get_cur_state = gpio_fan_get_cur_state,
433 .set_cur_state = gpio_fan_set_cur_state,
434 };
435
436 /*
437 * Translate OpenFirmware node properties into platform_data
438 */
gpio_fan_get_of_data(struct gpio_fan_data * fan_data)439 static int gpio_fan_get_of_data(struct gpio_fan_data *fan_data)
440 {
441 struct gpio_fan_speed *speed;
442 struct device *dev = fan_data->dev;
443 struct device_node *np = dev->of_node;
444 struct gpio_desc **gpios;
445 unsigned i;
446 u32 u;
447 struct property *prop;
448 const __be32 *p;
449
450 /* Alarm GPIO if one exists */
451 fan_data->alarm_gpio = devm_gpiod_get_optional(dev, "alarm", GPIOD_IN);
452 if (IS_ERR(fan_data->alarm_gpio))
453 return PTR_ERR(fan_data->alarm_gpio);
454
455 /* Fill GPIO pin array */
456 fan_data->num_gpios = gpiod_count(dev, NULL);
457 if (fan_data->num_gpios <= 0) {
458 if (fan_data->alarm_gpio)
459 return 0;
460 dev_err(dev, "DT properties empty / missing");
461 return -ENODEV;
462 }
463 gpios = devm_kcalloc(dev,
464 fan_data->num_gpios, sizeof(struct gpio_desc *),
465 GFP_KERNEL);
466 if (!gpios)
467 return -ENOMEM;
468 for (i = 0; i < fan_data->num_gpios; i++) {
469 gpios[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
470 if (IS_ERR(gpios[i]))
471 return PTR_ERR(gpios[i]);
472 }
473 fan_data->gpios = gpios;
474
475 /* Get number of RPM/ctrl_val pairs in speed map */
476 prop = of_find_property(np, "gpio-fan,speed-map", &i);
477 if (!prop) {
478 dev_err(dev, "gpio-fan,speed-map DT property missing");
479 return -ENODEV;
480 }
481 i = i / sizeof(u32);
482 if (i == 0 || i & 1) {
483 dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
484 return -ENODEV;
485 }
486 fan_data->num_speed = i / 2;
487
488 /*
489 * Populate speed map
490 * Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
491 * this needs splitting into pairs to create gpio_fan_speed structs
492 */
493 speed = devm_kcalloc(dev,
494 fan_data->num_speed, sizeof(struct gpio_fan_speed),
495 GFP_KERNEL);
496 if (!speed)
497 return -ENOMEM;
498 p = NULL;
499 for (i = 0; i < fan_data->num_speed; i++) {
500 p = of_prop_next_u32(prop, p, &u);
501 if (!p)
502 return -ENODEV;
503 speed[i].rpm = u;
504 p = of_prop_next_u32(prop, p, &u);
505 if (!p)
506 return -ENODEV;
507 speed[i].ctrl_val = u;
508 }
509 fan_data->speed = speed;
510
511 return 0;
512 }
513
514 static const struct of_device_id of_gpio_fan_match[] = {
515 { .compatible = "gpio-fan", },
516 {},
517 };
518 MODULE_DEVICE_TABLE(of, of_gpio_fan_match);
519
gpio_fan_stop(void * data)520 static void gpio_fan_stop(void *data)
521 {
522 struct gpio_fan_data *fan_data = data;
523
524 mutex_lock(&fan_data->lock);
525 set_fan_speed(data, 0);
526 mutex_unlock(&fan_data->lock);
527
528 pm_runtime_disable(fan_data->dev);
529 }
530
gpio_fan_probe(struct platform_device * pdev)531 static int gpio_fan_probe(struct platform_device *pdev)
532 {
533 int err;
534 struct gpio_fan_data *fan_data;
535 struct device *dev = &pdev->dev;
536 struct device_node *np = dev->of_node;
537
538 fan_data = devm_kzalloc(dev, sizeof(struct gpio_fan_data),
539 GFP_KERNEL);
540 if (!fan_data)
541 return -ENOMEM;
542
543 fan_data->dev = dev;
544 err = gpio_fan_get_of_data(fan_data);
545 if (err)
546 return err;
547
548 platform_set_drvdata(pdev, fan_data);
549 mutex_init(&fan_data->lock);
550
551 fan_data->supply = devm_regulator_get(dev, "fan");
552 if (IS_ERR(fan_data->supply))
553 return dev_err_probe(dev, PTR_ERR(fan_data->supply),
554 "Failed to get fan-supply");
555
556 /* Configure control GPIOs if available. */
557 if (fan_data->gpios && fan_data->num_gpios > 0) {
558 if (!fan_data->speed || fan_data->num_speed <= 1)
559 return -EINVAL;
560 err = fan_ctrl_init(fan_data);
561 if (err)
562 return err;
563 err = devm_add_action_or_reset(dev, gpio_fan_stop, fan_data);
564 if (err)
565 return err;
566 }
567
568 /* Make this driver part of hwmon class. */
569 fan_data->hwmon_dev =
570 devm_hwmon_device_register_with_groups(dev,
571 "gpio_fan", fan_data,
572 gpio_fan_groups);
573 if (IS_ERR(fan_data->hwmon_dev))
574 return PTR_ERR(fan_data->hwmon_dev);
575
576 /* Configure alarm GPIO if available. */
577 if (fan_data->alarm_gpio) {
578 err = fan_alarm_init(fan_data);
579 if (err)
580 return err;
581 }
582
583 pm_runtime_set_suspended(&pdev->dev);
584 pm_runtime_enable(&pdev->dev);
585 /* If current GPIO state is active, mark RPM as active as well */
586 if (fan_data->speed_index > 0) {
587 int ret;
588
589 ret = pm_runtime_resume_and_get(&pdev->dev);
590 if (ret)
591 return ret;
592 }
593
594 /* Optional cooling device register for Device tree platforms */
595 fan_data->cdev = devm_thermal_of_cooling_device_register(dev, np,
596 "gpio-fan", fan_data, &gpio_fan_cool_ops);
597
598 dev_info(dev, "GPIO fan initialized\n");
599
600 return 0;
601 }
602
gpio_fan_shutdown(struct platform_device * pdev)603 static void gpio_fan_shutdown(struct platform_device *pdev)
604 {
605 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
606
607 if (fan_data->gpios)
608 set_fan_speed(fan_data, 0);
609 }
610
gpio_fan_runtime_suspend(struct device * dev)611 static int gpio_fan_runtime_suspend(struct device *dev)
612 {
613 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
614 int ret = 0;
615
616 if (fan_data->supply)
617 ret = regulator_disable(fan_data->supply);
618
619 return ret;
620 }
621
gpio_fan_runtime_resume(struct device * dev)622 static int gpio_fan_runtime_resume(struct device *dev)
623 {
624 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
625 int ret = 0;
626
627 if (fan_data->supply)
628 ret = regulator_enable(fan_data->supply);
629
630 return ret;
631 }
632
gpio_fan_suspend(struct device * dev)633 static int gpio_fan_suspend(struct device *dev)
634 {
635 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
636 int ret = 0;
637
638 if (fan_data->gpios) {
639 fan_data->resume_speed = fan_data->speed_index;
640 mutex_lock(&fan_data->lock);
641 ret = set_fan_speed(fan_data, 0);
642 mutex_unlock(&fan_data->lock);
643 }
644
645 return ret;
646 }
647
gpio_fan_resume(struct device * dev)648 static int gpio_fan_resume(struct device *dev)
649 {
650 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
651 int ret = 0;
652
653 if (fan_data->gpios) {
654 mutex_lock(&fan_data->lock);
655 ret = set_fan_speed(fan_data, fan_data->resume_speed);
656 mutex_unlock(&fan_data->lock);
657 }
658
659 return ret;
660 }
661
662 static const struct dev_pm_ops gpio_fan_pm = {
663 RUNTIME_PM_OPS(gpio_fan_runtime_suspend,
664 gpio_fan_runtime_resume, NULL)
665 SYSTEM_SLEEP_PM_OPS(gpio_fan_suspend, gpio_fan_resume)
666 };
667
668 static struct platform_driver gpio_fan_driver = {
669 .probe = gpio_fan_probe,
670 .shutdown = gpio_fan_shutdown,
671 .driver = {
672 .name = "gpio-fan",
673 .pm = pm_ptr(&gpio_fan_pm),
674 .of_match_table = of_gpio_fan_match,
675 },
676 };
677
678 module_platform_driver(gpio_fan_driver);
679
680 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
681 MODULE_DESCRIPTION("GPIO FAN driver");
682 MODULE_LICENSE("GPL");
683 MODULE_ALIAS("platform:gpio-fan");
684