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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/mutex.h>
18#include <linux/hwmon.h>
19#include <linux/gpio/consumer.h>
20#include <linux/of.h>
21#include <linux/of_platform.h>
22#include <linux/thermal.h>
23
24struct gpio_fan_speed {
25 int rpm;
26 int ctrl_val;
27};
28
29struct gpio_fan_data {
30 struct device *dev;
31 struct device *hwmon_dev;
32 /* Cooling device if any */
33 struct thermal_cooling_device *cdev;
34 struct mutex lock; /* lock GPIOs operations. */
35 int num_gpios;
36 struct gpio_desc **gpios;
37 int num_speed;
38 struct gpio_fan_speed *speed;
39 int speed_index;
40#ifdef CONFIG_PM_SLEEP
41 int resume_speed;
42#endif
43 bool pwm_enable;
44 struct gpio_desc *alarm_gpio;
45 struct work_struct alarm_work;
46};
47
48/*
49 * Alarm GPIO.
50 */
51
52static void fan_alarm_notify(struct work_struct *ws)
53{
54 struct gpio_fan_data *fan_data =
55 container_of(ws, struct gpio_fan_data, alarm_work);
56
57 sysfs_notify(&fan_data->hwmon_dev->kobj, NULL, "fan1_alarm");
58 kobject_uevent(&fan_data->hwmon_dev->kobj, KOBJ_CHANGE);
59}
60
61static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
62{
63 struct gpio_fan_data *fan_data = dev_id;
64
65 schedule_work(&fan_data->alarm_work);
66
67 return IRQ_NONE;
68}
69
70static ssize_t fan1_alarm_show(struct device *dev,
71 struct device_attribute *attr, char *buf)
72{
73 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
74
75 return sprintf(buf, "%d\n",
76 gpiod_get_value_cansleep(fan_data->alarm_gpio));
77}
78
79static DEVICE_ATTR_RO(fan1_alarm);
80
81static int fan_alarm_init(struct gpio_fan_data *fan_data)
82{
83 int alarm_irq;
84 struct device *dev = fan_data->dev;
85
86 /*
87 * If the alarm GPIO don't support interrupts, just leave
88 * without initializing the fail notification support.
89 */
90 alarm_irq = gpiod_to_irq(fan_data->alarm_gpio);
91 if (alarm_irq <= 0)
92 return 0;
93
94 INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
95 irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
96 return devm_request_irq(dev, alarm_irq, fan_alarm_irq_handler,
97 IRQF_SHARED, "GPIO fan alarm", fan_data);
98}
99
100/*
101 * Control GPIOs.
102 */
103
104/* Must be called with fan_data->lock held, except during initialization. */
105static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
106{
107 int i;
108
109 for (i = 0; i < fan_data->num_gpios; i++)
110 gpiod_set_value_cansleep(fan_data->gpios[i],
111 (ctrl_val >> i) & 1);
112}
113
114static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
115{
116 int i;
117 int ctrl_val = 0;
118
119 for (i = 0; i < fan_data->num_gpios; i++) {
120 int value;
121
122 value = gpiod_get_value_cansleep(fan_data->gpios[i]);
123 ctrl_val |= (value << i);
124 }
125 return ctrl_val;
126}
127
128/* Must be called with fan_data->lock held, except during initialization. */
129static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
130{
131 if (fan_data->speed_index == speed_index)
132 return;
133
134 __set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
135 fan_data->speed_index = speed_index;
136}
137
138static int get_fan_speed_index(struct gpio_fan_data *fan_data)
139{
140 int ctrl_val = __get_fan_ctrl(fan_data);
141 int i;
142
143 for (i = 0; i < fan_data->num_speed; i++)
144 if (fan_data->speed[i].ctrl_val == ctrl_val)
145 return i;
146
147 dev_warn(fan_data->dev,
148 "missing speed array entry for GPIO value 0x%x\n", ctrl_val);
149
150 return -ENODEV;
151}
152
153static int rpm_to_speed_index(struct gpio_fan_data *fan_data, unsigned long rpm)
154{
155 struct gpio_fan_speed *speed = fan_data->speed;
156 int i;
157
158 for (i = 0; i < fan_data->num_speed; i++)
159 if (speed[i].rpm >= rpm)
160 return i;
161
162 return fan_data->num_speed - 1;
163}
164
165static ssize_t pwm1_show(struct device *dev, struct device_attribute *attr,
166 char *buf)
167{
168 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
169 u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);
170
171 return sprintf(buf, "%d\n", pwm);
172}
173
174static ssize_t pwm1_store(struct device *dev, struct device_attribute *attr,
175 const char *buf, size_t count)
176{
177 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
178 unsigned long pwm;
179 int speed_index;
180 int ret = count;
181
182 if (kstrtoul(buf, 10, &pwm) || pwm > 255)
183 return -EINVAL;
184
185 mutex_lock(&fan_data->lock);
186
187 if (!fan_data->pwm_enable) {
188 ret = -EPERM;
189 goto exit_unlock;
190 }
191
192 speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
193 set_fan_speed(fan_data, speed_index);
194
195exit_unlock:
196 mutex_unlock(&fan_data->lock);
197
198 return ret;
199}
200
201static ssize_t pwm1_enable_show(struct device *dev,
202 struct device_attribute *attr, char *buf)
203{
204 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
205
206 return sprintf(buf, "%d\n", fan_data->pwm_enable);
207}
208
209static ssize_t pwm1_enable_store(struct device *dev,
210 struct device_attribute *attr,
211 const char *buf, size_t count)
212{
213 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
214 unsigned long val;
215
216 if (kstrtoul(buf, 10, &val) || val > 1)
217 return -EINVAL;
218
219 if (fan_data->pwm_enable == val)
220 return count;
221
222 mutex_lock(&fan_data->lock);
223
224 fan_data->pwm_enable = val;
225
226 /* Disable manual control mode: set fan at full speed. */
227 if (val == 0)
228 set_fan_speed(fan_data, fan_data->num_speed - 1);
229
230 mutex_unlock(&fan_data->lock);
231
232 return count;
233}
234
235static ssize_t pwm1_mode_show(struct device *dev,
236 struct device_attribute *attr, char *buf)
237{
238 return sprintf(buf, "0\n");
239}
240
241static ssize_t fan1_min_show(struct device *dev,
242 struct device_attribute *attr, char *buf)
243{
244 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
245
246 return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
247}
248
249static ssize_t fan1_max_show(struct device *dev,
250 struct device_attribute *attr, char *buf)
251{
252 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
253
254 return sprintf(buf, "%d\n",
255 fan_data->speed[fan_data->num_speed - 1].rpm);
256}
257
258static ssize_t fan1_input_show(struct device *dev,
259 struct device_attribute *attr, char *buf)
260{
261 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
262
263 return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
264}
265
266static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
267 const char *buf, size_t count)
268{
269 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
270 unsigned long rpm;
271 int ret = count;
272
273 if (kstrtoul(buf, 10, &rpm))
274 return -EINVAL;
275
276 mutex_lock(&fan_data->lock);
277
278 if (!fan_data->pwm_enable) {
279 ret = -EPERM;
280 goto exit_unlock;
281 }
282
283 set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
284
285exit_unlock:
286 mutex_unlock(&fan_data->lock);
287
288 return ret;
289}
290
291static DEVICE_ATTR_RW(pwm1);
292static DEVICE_ATTR_RW(pwm1_enable);
293static DEVICE_ATTR_RO(pwm1_mode);
294static DEVICE_ATTR_RO(fan1_min);
295static DEVICE_ATTR_RO(fan1_max);
296static DEVICE_ATTR_RO(fan1_input);
297static DEVICE_ATTR(fan1_target, 0644, fan1_input_show, set_rpm);
298
299static umode_t gpio_fan_is_visible(struct kobject *kobj,
300 struct attribute *attr, int index)
301{
302 struct device *dev = container_of(kobj, struct device, kobj);
303 struct gpio_fan_data *data = dev_get_drvdata(dev);
304
305 if (index == 0 && !data->alarm_gpio)
306 return 0;
307 if (index > 0 && !data->gpios)
308 return 0;
309
310 return attr->mode;
311}
312
313static struct attribute *gpio_fan_attributes[] = {
314 &dev_attr_fan1_alarm.attr, /* 0 */
315 &dev_attr_pwm1.attr, /* 1 */
316 &dev_attr_pwm1_enable.attr,
317 &dev_attr_pwm1_mode.attr,
318 &dev_attr_fan1_input.attr,
319 &dev_attr_fan1_target.attr,
320 &dev_attr_fan1_min.attr,
321 &dev_attr_fan1_max.attr,
322 NULL
323};
324
325static const struct attribute_group gpio_fan_group = {
326 .attrs = gpio_fan_attributes,
327 .is_visible = gpio_fan_is_visible,
328};
329
330static const struct attribute_group *gpio_fan_groups[] = {
331 &gpio_fan_group,
332 NULL
333};
334
335static int fan_ctrl_init(struct gpio_fan_data *fan_data)
336{
337 int num_gpios = fan_data->num_gpios;
338 struct gpio_desc **gpios = fan_data->gpios;
339 int i, err;
340
341 for (i = 0; i < num_gpios; i++) {
342 /*
343 * The GPIO descriptors were retrieved with GPIOD_ASIS so here
344 * we set the GPIO into output mode, carefully preserving the
345 * current value by setting it to whatever it is already set
346 * (no surprise changes in default fan speed).
347 */
348 err = gpiod_direction_output(gpios[i],
349 gpiod_get_value_cansleep(gpios[i]));
350 if (err)
351 return err;
352 }
353
354 fan_data->pwm_enable = true; /* Enable manual fan speed control. */
355 fan_data->speed_index = get_fan_speed_index(fan_data);
356 if (fan_data->speed_index < 0)
357 return fan_data->speed_index;
358
359 return 0;
360}
361
362static int gpio_fan_get_max_state(struct thermal_cooling_device *cdev,
363 unsigned long *state)
364{
365 struct gpio_fan_data *fan_data = cdev->devdata;
366
367 if (!fan_data)
368 return -EINVAL;
369
370 *state = fan_data->num_speed - 1;
371 return 0;
372}
373
374static int gpio_fan_get_cur_state(struct thermal_cooling_device *cdev,
375 unsigned long *state)
376{
377 struct gpio_fan_data *fan_data = cdev->devdata;
378
379 if (!fan_data)
380 return -EINVAL;
381
382 *state = fan_data->speed_index;
383 return 0;
384}
385
386static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev,
387 unsigned long state)
388{
389 struct gpio_fan_data *fan_data = cdev->devdata;
390
391 if (!fan_data)
392 return -EINVAL;
393
394 set_fan_speed(fan_data, state);
395 return 0;
396}
397
398static const struct thermal_cooling_device_ops gpio_fan_cool_ops = {
399 .get_max_state = gpio_fan_get_max_state,
400 .get_cur_state = gpio_fan_get_cur_state,
401 .set_cur_state = gpio_fan_set_cur_state,
402};
403
404/*
405 * Translate OpenFirmware node properties into platform_data
406 */
407static int gpio_fan_get_of_data(struct gpio_fan_data *fan_data)
408{
409 struct gpio_fan_speed *speed;
410 struct device *dev = fan_data->dev;
411 struct device_node *np = dev->of_node;
412 struct gpio_desc **gpios;
413 unsigned i;
414 u32 u;
415 struct property *prop;
416 const __be32 *p;
417
418 /* Alarm GPIO if one exists */
419 fan_data->alarm_gpio = devm_gpiod_get_optional(dev, "alarm", GPIOD_IN);
420 if (IS_ERR(fan_data->alarm_gpio))
421 return PTR_ERR(fan_data->alarm_gpio);
422
423 /* Fill GPIO pin array */
424 fan_data->num_gpios = gpiod_count(dev, NULL);
425 if (fan_data->num_gpios <= 0) {
426 if (fan_data->alarm_gpio)
427 return 0;
428 dev_err(dev, "DT properties empty / missing");
429 return -ENODEV;
430 }
431 gpios = devm_kcalloc(dev,
432 fan_data->num_gpios, sizeof(struct gpio_desc *),
433 GFP_KERNEL);
434 if (!gpios)
435 return -ENOMEM;
436 for (i = 0; i < fan_data->num_gpios; i++) {
437 gpios[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
438 if (IS_ERR(gpios[i]))
439 return PTR_ERR(gpios[i]);
440 }
441 fan_data->gpios = gpios;
442
443 /* Get number of RPM/ctrl_val pairs in speed map */
444 prop = of_find_property(np, "gpio-fan,speed-map", &i);
445 if (!prop) {
446 dev_err(dev, "gpio-fan,speed-map DT property missing");
447 return -ENODEV;
448 }
449 i = i / sizeof(u32);
450 if (i == 0 || i & 1) {
451 dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
452 return -ENODEV;
453 }
454 fan_data->num_speed = i / 2;
455
456 /*
457 * Populate speed map
458 * Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
459 * this needs splitting into pairs to create gpio_fan_speed structs
460 */
461 speed = devm_kcalloc(dev,
462 fan_data->num_speed, sizeof(struct gpio_fan_speed),
463 GFP_KERNEL);
464 if (!speed)
465 return -ENOMEM;
466 p = NULL;
467 for (i = 0; i < fan_data->num_speed; i++) {
468 p = of_prop_next_u32(prop, p, &u);
469 if (!p)
470 return -ENODEV;
471 speed[i].rpm = u;
472 p = of_prop_next_u32(prop, p, &u);
473 if (!p)
474 return -ENODEV;
475 speed[i].ctrl_val = u;
476 }
477 fan_data->speed = speed;
478
479 return 0;
480}
481
482static const struct of_device_id of_gpio_fan_match[] = {
483 { .compatible = "gpio-fan", },
484 {},
485};
486MODULE_DEVICE_TABLE(of, of_gpio_fan_match);
487
488static void gpio_fan_stop(void *data)
489{
490 set_fan_speed(data, 0);
491}
492
493static int gpio_fan_probe(struct platform_device *pdev)
494{
495 int err;
496 struct gpio_fan_data *fan_data;
497 struct device *dev = &pdev->dev;
498 struct device_node *np = dev->of_node;
499
500 fan_data = devm_kzalloc(dev, sizeof(struct gpio_fan_data),
501 GFP_KERNEL);
502 if (!fan_data)
503 return -ENOMEM;
504
505 fan_data->dev = dev;
506 err = gpio_fan_get_of_data(fan_data);
507 if (err)
508 return err;
509
510 platform_set_drvdata(pdev, fan_data);
511 mutex_init(&fan_data->lock);
512
513 /* Configure control GPIOs if available. */
514 if (fan_data->gpios && fan_data->num_gpios > 0) {
515 if (!fan_data->speed || fan_data->num_speed <= 1)
516 return -EINVAL;
517 err = fan_ctrl_init(fan_data);
518 if (err)
519 return err;
520 err = devm_add_action_or_reset(dev, gpio_fan_stop, fan_data);
521 if (err)
522 return err;
523 }
524
525 /* Make this driver part of hwmon class. */
526 fan_data->hwmon_dev =
527 devm_hwmon_device_register_with_groups(dev,
528 "gpio_fan", fan_data,
529 gpio_fan_groups);
530 if (IS_ERR(fan_data->hwmon_dev))
531 return PTR_ERR(fan_data->hwmon_dev);
532
533 /* Configure alarm GPIO if available. */
534 if (fan_data->alarm_gpio) {
535 err = fan_alarm_init(fan_data);
536 if (err)
537 return err;
538 }
539
540 /* Optional cooling device register for Device tree platforms */
541 fan_data->cdev = devm_thermal_of_cooling_device_register(dev, np,
542 "gpio-fan", fan_data, &gpio_fan_cool_ops);
543
544 dev_info(dev, "GPIO fan initialized\n");
545
546 return 0;
547}
548
549static void gpio_fan_shutdown(struct platform_device *pdev)
550{
551 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
552
553 if (fan_data->gpios)
554 set_fan_speed(fan_data, 0);
555}
556
557#ifdef CONFIG_PM_SLEEP
558static int gpio_fan_suspend(struct device *dev)
559{
560 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
561
562 if (fan_data->gpios) {
563 fan_data->resume_speed = fan_data->speed_index;
564 set_fan_speed(fan_data, 0);
565 }
566
567 return 0;
568}
569
570static int gpio_fan_resume(struct device *dev)
571{
572 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
573
574 if (fan_data->gpios)
575 set_fan_speed(fan_data, fan_data->resume_speed);
576
577 return 0;
578}
579
580static SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);
581#define GPIO_FAN_PM (&gpio_fan_pm)
582#else
583#define GPIO_FAN_PM NULL
584#endif
585
586static struct platform_driver gpio_fan_driver = {
587 .probe = gpio_fan_probe,
588 .shutdown = gpio_fan_shutdown,
589 .driver = {
590 .name = "gpio-fan",
591 .pm = GPIO_FAN_PM,
592 .of_match_table = of_match_ptr(of_gpio_fan_match),
593 },
594};
595
596module_platform_driver(gpio_fan_driver);
597
598MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
599MODULE_DESCRIPTION("GPIO FAN driver");
600MODULE_LICENSE("GPL");
601MODULE_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
38struct gpio_fan_data {
39 struct platform_device *pdev;
40 struct device *hwmon_dev;
41 struct mutex lock; /* lock GPIOs operations. */
42 int num_ctrl;
43 unsigned *ctrl;
44 int num_speed;
45 struct gpio_fan_speed *speed;
46 int speed_index;
47#ifdef CONFIG_PM_SLEEP
48 int resume_speed;
49#endif
50 bool pwm_enable;
51 struct gpio_fan_alarm *alarm;
52 struct work_struct alarm_work;
53};
54
55/*
56 * Alarm GPIO.
57 */
58
59static void fan_alarm_notify(struct work_struct *ws)
60{
61 struct gpio_fan_data *fan_data =
62 container_of(ws, struct gpio_fan_data, alarm_work);
63
64 sysfs_notify(&fan_data->pdev->dev.kobj, NULL, "fan1_alarm");
65 kobject_uevent(&fan_data->pdev->dev.kobj, KOBJ_CHANGE);
66}
67
68static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
69{
70 struct gpio_fan_data *fan_data = dev_id;
71
72 schedule_work(&fan_data->alarm_work);
73
74 return IRQ_NONE;
75}
76
77static ssize_t show_fan_alarm(struct device *dev,
78 struct device_attribute *attr, char *buf)
79{
80 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
81 struct gpio_fan_alarm *alarm = fan_data->alarm;
82 int value = gpio_get_value(alarm->gpio);
83
84 if (alarm->active_low)
85 value = !value;
86
87 return sprintf(buf, "%d\n", value);
88}
89
90static DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL);
91
92static int fan_alarm_init(struct gpio_fan_data *fan_data,
93 struct gpio_fan_alarm *alarm)
94{
95 int err;
96 int alarm_irq;
97 struct platform_device *pdev = fan_data->pdev;
98
99 fan_data->alarm = alarm;
100
101 err = devm_gpio_request(&pdev->dev, alarm->gpio, "GPIO fan alarm");
102 if (err)
103 return err;
104
105 err = gpio_direction_input(alarm->gpio);
106 if (err)
107 return err;
108
109 /*
110 * If the alarm GPIO don't support interrupts, just leave
111 * without initializing the fail notification support.
112 */
113 alarm_irq = gpio_to_irq(alarm->gpio);
114 if (alarm_irq < 0)
115 return 0;
116
117 INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
118 irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
119 err = devm_request_irq(&pdev->dev, alarm_irq, fan_alarm_irq_handler,
120 IRQF_SHARED, "GPIO fan alarm", fan_data);
121 return err;
122}
123
124/*
125 * Control GPIOs.
126 */
127
128/* Must be called with fan_data->lock held, except during initialization. */
129static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
130{
131 int i;
132
133 for (i = 0; i < fan_data->num_ctrl; i++)
134 gpio_set_value(fan_data->ctrl[i], (ctrl_val >> i) & 1);
135}
136
137static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
138{
139 int i;
140 int ctrl_val = 0;
141
142 for (i = 0; i < fan_data->num_ctrl; i++) {
143 int value;
144
145 value = gpio_get_value(fan_data->ctrl[i]);
146 ctrl_val |= (value << i);
147 }
148 return ctrl_val;
149}
150
151/* Must be called with fan_data->lock held, except during initialization. */
152static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
153{
154 if (fan_data->speed_index == speed_index)
155 return;
156
157 __set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
158 fan_data->speed_index = speed_index;
159}
160
161static int get_fan_speed_index(struct gpio_fan_data *fan_data)
162{
163 int ctrl_val = __get_fan_ctrl(fan_data);
164 int i;
165
166 for (i = 0; i < fan_data->num_speed; i++)
167 if (fan_data->speed[i].ctrl_val == ctrl_val)
168 return i;
169
170 dev_warn(&fan_data->pdev->dev,
171 "missing speed array entry for GPIO value 0x%x\n", ctrl_val);
172
173 return -ENODEV;
174}
175
176static int rpm_to_speed_index(struct gpio_fan_data *fan_data, int rpm)
177{
178 struct gpio_fan_speed *speed = fan_data->speed;
179 int i;
180
181 for (i = 0; i < fan_data->num_speed; i++)
182 if (speed[i].rpm >= rpm)
183 return i;
184
185 return fan_data->num_speed - 1;
186}
187
188static ssize_t show_pwm(struct device *dev,
189 struct device_attribute *attr, char *buf)
190{
191 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
192 u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);
193
194 return sprintf(buf, "%d\n", pwm);
195}
196
197static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
198 const char *buf, size_t count)
199{
200 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
201 unsigned long pwm;
202 int speed_index;
203 int ret = count;
204
205 if (kstrtoul(buf, 10, &pwm) || pwm > 255)
206 return -EINVAL;
207
208 mutex_lock(&fan_data->lock);
209
210 if (!fan_data->pwm_enable) {
211 ret = -EPERM;
212 goto exit_unlock;
213 }
214
215 speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
216 set_fan_speed(fan_data, speed_index);
217
218exit_unlock:
219 mutex_unlock(&fan_data->lock);
220
221 return ret;
222}
223
224static ssize_t show_pwm_enable(struct device *dev,
225 struct device_attribute *attr, char *buf)
226{
227 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
228
229 return sprintf(buf, "%d\n", fan_data->pwm_enable);
230}
231
232static ssize_t set_pwm_enable(struct device *dev, 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
238 if (kstrtoul(buf, 10, &val) || val > 1)
239 return -EINVAL;
240
241 if (fan_data->pwm_enable == val)
242 return count;
243
244 mutex_lock(&fan_data->lock);
245
246 fan_data->pwm_enable = val;
247
248 /* Disable manual control mode: set fan at full speed. */
249 if (val == 0)
250 set_fan_speed(fan_data, fan_data->num_speed - 1);
251
252 mutex_unlock(&fan_data->lock);
253
254 return count;
255}
256
257static ssize_t show_pwm_mode(struct device *dev,
258 struct device_attribute *attr, char *buf)
259{
260 return sprintf(buf, "0\n");
261}
262
263static ssize_t show_rpm_min(struct device *dev,
264 struct device_attribute *attr, char *buf)
265{
266 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
267
268 return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
269}
270
271static ssize_t show_rpm_max(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",
277 fan_data->speed[fan_data->num_speed - 1].rpm);
278}
279
280static ssize_t show_rpm(struct device *dev,
281 struct device_attribute *attr, char *buf)
282{
283 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
284
285 return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
286}
287
288static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
289 const char *buf, size_t count)
290{
291 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
292 unsigned long rpm;
293 int ret = count;
294
295 if (kstrtoul(buf, 10, &rpm))
296 return -EINVAL;
297
298 mutex_lock(&fan_data->lock);
299
300 if (!fan_data->pwm_enable) {
301 ret = -EPERM;
302 goto exit_unlock;
303 }
304
305 set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
306
307exit_unlock:
308 mutex_unlock(&fan_data->lock);
309
310 return ret;
311}
312
313static DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm);
314static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
315 show_pwm_enable, set_pwm_enable);
316static DEVICE_ATTR(pwm1_mode, S_IRUGO, show_pwm_mode, NULL);
317static DEVICE_ATTR(fan1_min, S_IRUGO, show_rpm_min, NULL);
318static DEVICE_ATTR(fan1_max, S_IRUGO, show_rpm_max, NULL);
319static DEVICE_ATTR(fan1_input, S_IRUGO, show_rpm, NULL);
320static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_rpm, set_rpm);
321
322static umode_t gpio_fan_is_visible(struct kobject *kobj,
323 struct attribute *attr, int index)
324{
325 struct device *dev = container_of(kobj, struct device, kobj);
326 struct gpio_fan_data *data = dev_get_drvdata(dev);
327
328 if (index == 0 && !data->alarm)
329 return 0;
330 if (index > 0 && !data->ctrl)
331 return 0;
332
333 return attr->mode;
334}
335
336static 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
348static const struct attribute_group gpio_fan_group = {
349 .attrs = gpio_fan_attributes,
350 .is_visible = gpio_fan_is_visible,
351};
352
353static const struct attribute_group *gpio_fan_groups[] = {
354 &gpio_fan_group,
355 NULL
356};
357
358static int fan_ctrl_init(struct gpio_fan_data *fan_data,
359 struct gpio_fan_platform_data *pdata)
360{
361 struct platform_device *pdev = fan_data->pdev;
362 int num_ctrl = pdata->num_ctrl;
363 unsigned *ctrl = pdata->ctrl;
364 int i, err;
365
366 for (i = 0; i < num_ctrl; i++) {
367 err = devm_gpio_request(&pdev->dev, ctrl[i],
368 "GPIO fan control");
369 if (err)
370 return err;
371
372 err = gpio_direction_output(ctrl[i], gpio_get_value(ctrl[i]));
373 if (err)
374 return err;
375 }
376
377 fan_data->num_ctrl = num_ctrl;
378 fan_data->ctrl = ctrl;
379 fan_data->num_speed = pdata->num_speed;
380 fan_data->speed = pdata->speed;
381 fan_data->pwm_enable = true; /* Enable manual fan speed control. */
382 fan_data->speed_index = get_fan_speed_index(fan_data);
383 if (fan_data->speed_index < 0)
384 return fan_data->speed_index;
385
386 return 0;
387}
388
389#ifdef CONFIG_OF_GPIO
390/*
391 * Translate OpenFirmware node properties into platform_data
392 */
393static int gpio_fan_get_of_pdata(struct device *dev,
394 struct gpio_fan_platform_data *pdata)
395{
396 struct device_node *node;
397 struct gpio_fan_speed *speed;
398 unsigned *ctrl;
399 unsigned i;
400 u32 u;
401 struct property *prop;
402 const __be32 *p;
403
404 node = dev->of_node;
405
406 /* Fill GPIO pin array */
407 pdata->num_ctrl = of_gpio_count(node);
408 if (pdata->num_ctrl <= 0) {
409 dev_err(dev, "gpios DT property empty / missing");
410 return -ENODEV;
411 }
412 ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned),
413 GFP_KERNEL);
414 if (!ctrl)
415 return -ENOMEM;
416 for (i = 0; i < pdata->num_ctrl; i++) {
417 int val;
418
419 val = of_get_gpio(node, i);
420 if (val < 0)
421 return val;
422 ctrl[i] = val;
423 }
424 pdata->ctrl = ctrl;
425
426 /* Get number of RPM/ctrl_val pairs in speed map */
427 prop = of_find_property(node, "gpio-fan,speed-map", &i);
428 if (!prop) {
429 dev_err(dev, "gpio-fan,speed-map DT property missing");
430 return -ENODEV;
431 }
432 i = i / sizeof(u32);
433 if (i == 0 || i & 1) {
434 dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
435 return -ENODEV;
436 }
437 pdata->num_speed = i / 2;
438
439 /*
440 * Populate speed map
441 * Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
442 * this needs splitting into pairs to create gpio_fan_speed structs
443 */
444 speed = devm_kzalloc(dev,
445 pdata->num_speed * sizeof(struct gpio_fan_speed),
446 GFP_KERNEL);
447 if (!speed)
448 return -ENOMEM;
449 p = NULL;
450 for (i = 0; i < pdata->num_speed; i++) {
451 p = of_prop_next_u32(prop, p, &u);
452 if (!p)
453 return -ENODEV;
454 speed[i].rpm = u;
455 p = of_prop_next_u32(prop, p, &u);
456 if (!p)
457 return -ENODEV;
458 speed[i].ctrl_val = u;
459 }
460 pdata->speed = speed;
461
462 /* Alarm GPIO if one exists */
463 if (of_gpio_named_count(node, "alarm-gpios") > 0) {
464 struct gpio_fan_alarm *alarm;
465 int val;
466 enum of_gpio_flags flags;
467
468 alarm = devm_kzalloc(dev, sizeof(struct gpio_fan_alarm),
469 GFP_KERNEL);
470 if (!alarm)
471 return -ENOMEM;
472
473 val = of_get_named_gpio_flags(node, "alarm-gpios", 0, &flags);
474 if (val < 0)
475 return val;
476 alarm->gpio = val;
477 alarm->active_low = flags & OF_GPIO_ACTIVE_LOW;
478
479 pdata->alarm = alarm;
480 }
481
482 return 0;
483}
484
485static struct of_device_id of_gpio_fan_match[] = {
486 { .compatible = "gpio-fan", },
487 {},
488};
489#endif /* CONFIG_OF_GPIO */
490
491static int gpio_fan_probe(struct platform_device *pdev)
492{
493 int err;
494 struct gpio_fan_data *fan_data;
495 struct gpio_fan_platform_data *pdata = dev_get_platdata(&pdev->dev);
496
497#ifdef CONFIG_OF_GPIO
498 if (!pdata) {
499 pdata = devm_kzalloc(&pdev->dev,
500 sizeof(struct gpio_fan_platform_data),
501 GFP_KERNEL);
502 if (!pdata)
503 return -ENOMEM;
504
505 err = gpio_fan_get_of_pdata(&pdev->dev, pdata);
506 if (err)
507 return err;
508 }
509#else /* CONFIG_OF_GPIO */
510 if (!pdata)
511 return -EINVAL;
512#endif /* CONFIG_OF_GPIO */
513
514 fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data),
515 GFP_KERNEL);
516 if (!fan_data)
517 return -ENOMEM;
518
519 fan_data->pdev = pdev;
520 platform_set_drvdata(pdev, fan_data);
521 mutex_init(&fan_data->lock);
522
523 /* Configure alarm GPIO if available. */
524 if (pdata->alarm) {
525 err = fan_alarm_init(fan_data, pdata->alarm);
526 if (err)
527 return err;
528 }
529
530 /* Configure control GPIOs if available. */
531 if (pdata->ctrl && pdata->num_ctrl > 0) {
532 if (!pdata->speed || pdata->num_speed <= 1)
533 return -EINVAL;
534 err = fan_ctrl_init(fan_data, pdata);
535 if (err)
536 return err;
537 }
538
539 /* Make this driver part of hwmon class. */
540 fan_data->hwmon_dev = hwmon_device_register_with_groups(&pdev->dev,
541 "gpio-fan", fan_data,
542 gpio_fan_groups);
543 if (IS_ERR(fan_data->hwmon_dev))
544 return PTR_ERR(fan_data->hwmon_dev);
545
546 dev_info(&pdev->dev, "GPIO fan initialized\n");
547
548 return 0;
549}
550
551static int gpio_fan_remove(struct platform_device *pdev)
552{
553 struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
554
555 hwmon_device_unregister(fan_data->hwmon_dev);
556
557 return 0;
558}
559
560#ifdef CONFIG_PM_SLEEP
561static int gpio_fan_suspend(struct device *dev)
562{
563 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
564
565 if (fan_data->ctrl) {
566 fan_data->resume_speed = fan_data->speed_index;
567 set_fan_speed(fan_data, 0);
568 }
569
570 return 0;
571}
572
573static int gpio_fan_resume(struct device *dev)
574{
575 struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
576
577 if (fan_data->ctrl)
578 set_fan_speed(fan_data, fan_data->resume_speed);
579
580 return 0;
581}
582
583static SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);
584#define GPIO_FAN_PM (&gpio_fan_pm)
585#else
586#define GPIO_FAN_PM NULL
587#endif
588
589static struct platform_driver gpio_fan_driver = {
590 .probe = gpio_fan_probe,
591 .remove = gpio_fan_remove,
592 .driver = {
593 .name = "gpio-fan",
594 .pm = GPIO_FAN_PM,
595#ifdef CONFIG_OF_GPIO
596 .of_match_table = of_match_ptr(of_gpio_fan_match),
597#endif
598 },
599};
600
601module_platform_driver(gpio_fan_driver);
602
603MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
604MODULE_DESCRIPTION("GPIO FAN driver");
605MODULE_LICENSE("GPL");
606MODULE_ALIAS("platform:gpio-fan");