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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
43 struct thermal_cooling_device *cdev;
44 struct mutex lock;
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
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 fan1_alarm_show(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_RO(fan1_alarm);
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
114
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
129
130
131
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
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 pwm1_show(struct device *dev, struct device_attribute *attr,
192 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 pwm1_store(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 pwm1_enable_show(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 pwm1_enable_store(struct device *dev,
236 struct device_attribute *attr,
237 const char *buf, size_t count)
238{
239 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
240 unsigned long val;
241
242 if (kstrtoul(buf, 10, &val) || val > 1)
243 return -EINVAL;
244
245 if (fan_data->pwm_enable == val)
246 return count;
247
248 mutex_lock(&fan_data->lock);
249
250 fan_data->pwm_enable = val;
251
252
253 if (val == 0)
254 set_fan_speed(fan_data, fan_data->num_speed - 1);
255
256 mutex_unlock(&fan_data->lock);
257
258 return count;
259}
260
261static ssize_t pwm1_mode_show(struct device *dev,
262 struct device_attribute *attr, char *buf)
263{
264 return sprintf(buf, "0\n");
265}
266
267static ssize_t fan1_min_show(struct device *dev,
268 struct device_attribute *attr, char *buf)
269{
270 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
271
272 return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
273}
274
275static ssize_t fan1_max_show(struct device *dev,
276 struct device_attribute *attr, char *buf)
277{
278 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
279
280 return sprintf(buf, "%d\n",
281 fan_data->speed[fan_data->num_speed - 1].rpm);
282}
283
284static ssize_t fan1_input_show(struct device *dev,
285 struct device_attribute *attr, char *buf)
286{
287 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
288
289 return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
290}
291
292static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
293 const char *buf, size_t count)
294{
295 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
296 unsigned long rpm;
297 int ret = count;
298
299 if (kstrtoul(buf, 10, &rpm))
300 return -EINVAL;
301
302 mutex_lock(&fan_data->lock);
303
304 if (!fan_data->pwm_enable) {
305 ret = -EPERM;
306 goto exit_unlock;
307 }
308
309 set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
310
311exit_unlock:
312 mutex_unlock(&fan_data->lock);
313
314 return ret;
315}
316
317static DEVICE_ATTR_RW(pwm1);
318static DEVICE_ATTR_RW(pwm1_enable);
319static DEVICE_ATTR_RO(pwm1_mode);
320static DEVICE_ATTR_RO(fan1_min);
321static DEVICE_ATTR_RO(fan1_max);
322static DEVICE_ATTR_RO(fan1_input);
323static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, fan1_input_show, 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,
341 &dev_attr_pwm1.attr,
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;
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
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
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
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
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
509
510
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
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
564 if (!pdata)
565 return -EINVAL;
566#endif
567
568 fan_data->pdev = pdev;
569 platform_set_drvdata(pdev, fan_data);
570 mutex_init(&fan_data->lock);
571
572
573 if (pdata->alarm) {
574 err = fan_alarm_init(fan_data, pdata->alarm);
575 if (err)
576 return err;
577 }
578
579
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
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
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
602
603 fan_data->cdev = thermal_cooling_device_register("gpio-fan", fan_data,
604 &gpio_fan_cool_ops);
605#endif
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");
678
