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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");
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");