2 * gpio-fan.c - Hwmon driver for fans connected to GPIO lines.
4 * Copyright (C) 2010 LaCie
6 * Author: Simon Guinot <sguinot@lacie.com>
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.
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.
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
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>
35 #include <linux/of_platform.h>
36 #include <linux/of_gpio.h>
37 #include <linux/thermal.h>
39 struct gpio_fan_data
{
40 struct platform_device
*pdev
;
41 struct device
*hwmon_dev
;
42 /* Cooling device if any */
43 struct thermal_cooling_device
*cdev
;
44 struct mutex lock
; /* lock GPIOs operations. */
48 struct gpio_fan_speed
*speed
;
50 #ifdef CONFIG_PM_SLEEP
54 struct gpio_fan_alarm
*alarm
;
55 struct work_struct alarm_work
;
62 static void fan_alarm_notify(struct work_struct
*ws
)
64 struct gpio_fan_data
*fan_data
=
65 container_of(ws
, struct gpio_fan_data
, alarm_work
);
67 sysfs_notify(&fan_data
->pdev
->dev
.kobj
, NULL
, "fan1_alarm");
68 kobject_uevent(&fan_data
->pdev
->dev
.kobj
, KOBJ_CHANGE
);
71 static irqreturn_t
fan_alarm_irq_handler(int irq
, void *dev_id
)
73 struct gpio_fan_data
*fan_data
= dev_id
;
75 schedule_work(&fan_data
->alarm_work
);
80 static ssize_t
show_fan_alarm(struct device
*dev
,
81 struct device_attribute
*attr
, char *buf
)
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
);
87 if (alarm
->active_low
)
90 return sprintf(buf
, "%d\n", value
);
93 static DEVICE_ATTR(fan1_alarm
, S_IRUGO
, show_fan_alarm
, NULL
);
95 static int fan_alarm_init(struct gpio_fan_data
*fan_data
,
96 struct gpio_fan_alarm
*alarm
)
100 struct platform_device
*pdev
= fan_data
->pdev
;
102 fan_data
->alarm
= alarm
;
104 err
= devm_gpio_request(&pdev
->dev
, alarm
->gpio
, "GPIO fan alarm");
108 err
= gpio_direction_input(alarm
->gpio
);
113 * If the alarm GPIO don't support interrupts, just leave
114 * without initializing the fail notification support.
116 alarm_irq
= gpio_to_irq(alarm
->gpio
);
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
);
131 /* Must be called with fan_data->lock held, except during initialization. */
132 static void __set_fan_ctrl(struct gpio_fan_data
*fan_data
, int ctrl_val
)
136 for (i
= 0; i
< fan_data
->num_ctrl
; i
++)
137 gpio_set_value_cansleep(fan_data
->ctrl
[i
], (ctrl_val
>> i
) & 1);
140 static int __get_fan_ctrl(struct gpio_fan_data
*fan_data
)
145 for (i
= 0; i
< fan_data
->num_ctrl
; i
++) {
148 value
= gpio_get_value_cansleep(fan_data
->ctrl
[i
]);
149 ctrl_val
|= (value
<< i
);
154 /* Must be called with fan_data->lock held, except during initialization. */
155 static void set_fan_speed(struct gpio_fan_data
*fan_data
, int speed_index
)
157 if (fan_data
->speed_index
== speed_index
)
160 __set_fan_ctrl(fan_data
, fan_data
->speed
[speed_index
].ctrl_val
);
161 fan_data
->speed_index
= speed_index
;
164 static int get_fan_speed_index(struct gpio_fan_data
*fan_data
)
166 int ctrl_val
= __get_fan_ctrl(fan_data
);
169 for (i
= 0; i
< fan_data
->num_speed
; i
++)
170 if (fan_data
->speed
[i
].ctrl_val
== ctrl_val
)
173 dev_warn(&fan_data
->pdev
->dev
,
174 "missing speed array entry for GPIO value 0x%x\n", ctrl_val
);
179 static int rpm_to_speed_index(struct gpio_fan_data
*fan_data
, unsigned long rpm
)
181 struct gpio_fan_speed
*speed
= fan_data
->speed
;
184 for (i
= 0; i
< fan_data
->num_speed
; i
++)
185 if (speed
[i
].rpm
>= rpm
)
188 return fan_data
->num_speed
- 1;
191 static ssize_t
show_pwm(struct device
*dev
,
192 struct device_attribute
*attr
, char *buf
)
194 struct gpio_fan_data
*fan_data
= dev_get_drvdata(dev
);
195 u8 pwm
= fan_data
->speed_index
* 255 / (fan_data
->num_speed
- 1);
197 return sprintf(buf
, "%d\n", pwm
);
200 static ssize_t
set_pwm(struct device
*dev
, struct device_attribute
*attr
,
201 const char *buf
, size_t count
)
203 struct gpio_fan_data
*fan_data
= dev_get_drvdata(dev
);
208 if (kstrtoul(buf
, 10, &pwm
) || pwm
> 255)
211 mutex_lock(&fan_data
->lock
);
213 if (!fan_data
->pwm_enable
) {
218 speed_index
= DIV_ROUND_UP(pwm
* (fan_data
->num_speed
- 1), 255);
219 set_fan_speed(fan_data
, speed_index
);
222 mutex_unlock(&fan_data
->lock
);
227 static ssize_t
show_pwm_enable(struct device
*dev
,
228 struct device_attribute
*attr
, char *buf
)
230 struct gpio_fan_data
*fan_data
= dev_get_drvdata(dev
);
232 return sprintf(buf
, "%d\n", fan_data
->pwm_enable
);
235 static ssize_t
set_pwm_enable(struct device
*dev
, struct device_attribute
*attr
,
236 const char *buf
, size_t count
)
238 struct gpio_fan_data
*fan_data
= dev_get_drvdata(dev
);
241 if (kstrtoul(buf
, 10, &val
) || val
> 1)
244 if (fan_data
->pwm_enable
== val
)
247 mutex_lock(&fan_data
->lock
);
249 fan_data
->pwm_enable
= val
;
251 /* Disable manual control mode: set fan at full speed. */
253 set_fan_speed(fan_data
, fan_data
->num_speed
- 1);
255 mutex_unlock(&fan_data
->lock
);
260 static ssize_t
show_pwm_mode(struct device
*dev
,
261 struct device_attribute
*attr
, char *buf
)
263 return sprintf(buf
, "0\n");
266 static ssize_t
show_rpm_min(struct device
*dev
,
267 struct device_attribute
*attr
, char *buf
)
269 struct gpio_fan_data
*fan_data
= dev_get_drvdata(dev
);
271 return sprintf(buf
, "%d\n", fan_data
->speed
[0].rpm
);
274 static ssize_t
show_rpm_max(struct device
*dev
,
275 struct device_attribute
*attr
, char *buf
)
277 struct gpio_fan_data
*fan_data
= dev_get_drvdata(dev
);
279 return sprintf(buf
, "%d\n",
280 fan_data
->speed
[fan_data
->num_speed
- 1].rpm
);
283 static ssize_t
show_rpm(struct device
*dev
,
284 struct device_attribute
*attr
, char *buf
)
286 struct gpio_fan_data
*fan_data
= dev_get_drvdata(dev
);
288 return sprintf(buf
, "%d\n", fan_data
->speed
[fan_data
->speed_index
].rpm
);
291 static ssize_t
set_rpm(struct device
*dev
, struct device_attribute
*attr
,
292 const char *buf
, size_t count
)
294 struct gpio_fan_data
*fan_data
= dev_get_drvdata(dev
);
298 if (kstrtoul(buf
, 10, &rpm
))
301 mutex_lock(&fan_data
->lock
);
303 if (!fan_data
->pwm_enable
) {
308 set_fan_speed(fan_data
, rpm_to_speed_index(fan_data
, rpm
));
311 mutex_unlock(&fan_data
->lock
);
316 static DEVICE_ATTR(pwm1
, S_IRUGO
| S_IWUSR
, show_pwm
, set_pwm
);
317 static DEVICE_ATTR(pwm1_enable
, S_IRUGO
| S_IWUSR
,
318 show_pwm_enable
, set_pwm_enable
);
319 static DEVICE_ATTR(pwm1_mode
, S_IRUGO
, show_pwm_mode
, NULL
);
320 static DEVICE_ATTR(fan1_min
, S_IRUGO
, show_rpm_min
, NULL
);
321 static DEVICE_ATTR(fan1_max
, S_IRUGO
, show_rpm_max
, NULL
);
322 static DEVICE_ATTR(fan1_input
, S_IRUGO
, show_rpm
, NULL
);
323 static DEVICE_ATTR(fan1_target
, S_IRUGO
| S_IWUSR
, show_rpm
, set_rpm
);
325 static umode_t
gpio_fan_is_visible(struct kobject
*kobj
,
326 struct attribute
*attr
, int index
)
328 struct device
*dev
= container_of(kobj
, struct device
, kobj
);
329 struct gpio_fan_data
*data
= dev_get_drvdata(dev
);
331 if (index
== 0 && !data
->alarm
)
333 if (index
> 0 && !data
->ctrl
)
339 static struct attribute
*gpio_fan_attributes
[] = {
340 &dev_attr_fan1_alarm
.attr
, /* 0 */
341 &dev_attr_pwm1
.attr
, /* 1 */
342 &dev_attr_pwm1_enable
.attr
,
343 &dev_attr_pwm1_mode
.attr
,
344 &dev_attr_fan1_input
.attr
,
345 &dev_attr_fan1_target
.attr
,
346 &dev_attr_fan1_min
.attr
,
347 &dev_attr_fan1_max
.attr
,
351 static const struct attribute_group gpio_fan_group
= {
352 .attrs
= gpio_fan_attributes
,
353 .is_visible
= gpio_fan_is_visible
,
356 static const struct attribute_group
*gpio_fan_groups
[] = {
361 static int fan_ctrl_init(struct gpio_fan_data
*fan_data
,
362 struct gpio_fan_platform_data
*pdata
)
364 struct platform_device
*pdev
= fan_data
->pdev
;
365 int num_ctrl
= pdata
->num_ctrl
;
366 unsigned *ctrl
= pdata
->ctrl
;
369 for (i
= 0; i
< num_ctrl
; i
++) {
370 err
= devm_gpio_request(&pdev
->dev
, ctrl
[i
],
375 err
= gpio_direction_output(ctrl
[i
],
376 gpio_get_value_cansleep(ctrl
[i
]));
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
;
393 static int gpio_fan_get_max_state(struct thermal_cooling_device
*cdev
,
394 unsigned long *state
)
396 struct gpio_fan_data
*fan_data
= cdev
->devdata
;
401 *state
= fan_data
->num_speed
- 1;
405 static int gpio_fan_get_cur_state(struct thermal_cooling_device
*cdev
,
406 unsigned long *state
)
408 struct gpio_fan_data
*fan_data
= cdev
->devdata
;
413 *state
= fan_data
->speed_index
;
417 static int gpio_fan_set_cur_state(struct thermal_cooling_device
*cdev
,
420 struct gpio_fan_data
*fan_data
= cdev
->devdata
;
425 set_fan_speed(fan_data
, state
);
429 static 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
,
435 #ifdef CONFIG_OF_GPIO
437 * Translate OpenFirmware node properties into platform_data
439 static int gpio_fan_get_of_pdata(struct device
*dev
,
440 struct gpio_fan_platform_data
*pdata
)
442 struct device_node
*node
;
443 struct gpio_fan_speed
*speed
;
447 struct property
*prop
;
452 /* Alarm GPIO if one exists */
453 if (of_gpio_named_count(node
, "alarm-gpios") > 0) {
454 struct gpio_fan_alarm
*alarm
;
456 enum of_gpio_flags flags
;
458 alarm
= devm_kzalloc(dev
, sizeof(struct gpio_fan_alarm
),
463 val
= of_get_named_gpio_flags(node
, "alarm-gpios", 0, &flags
);
467 alarm
->active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
469 pdata
->alarm
= alarm
;
472 /* Fill GPIO pin array */
473 pdata
->num_ctrl
= of_gpio_count(node
);
474 if (pdata
->num_ctrl
<= 0) {
477 dev_err(dev
, "DT properties empty / missing");
480 ctrl
= devm_kzalloc(dev
, pdata
->num_ctrl
* sizeof(unsigned),
484 for (i
= 0; i
< pdata
->num_ctrl
; i
++) {
487 val
= of_get_gpio(node
, i
);
494 /* Get number of RPM/ctrl_val pairs in speed map */
495 prop
= of_find_property(node
, "gpio-fan,speed-map", &i
);
497 dev_err(dev
, "gpio-fan,speed-map DT property missing");
501 if (i
== 0 || i
& 1) {
502 dev_err(dev
, "gpio-fan,speed-map contains zero/odd number of entries");
505 pdata
->num_speed
= i
/ 2;
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
512 speed
= devm_kzalloc(dev
,
513 pdata
->num_speed
* sizeof(struct gpio_fan_speed
),
518 for (i
= 0; i
< pdata
->num_speed
; i
++) {
519 p
= of_prop_next_u32(prop
, p
, &u
);
523 p
= of_prop_next_u32(prop
, p
, &u
);
526 speed
[i
].ctrl_val
= u
;
528 pdata
->speed
= speed
;
533 static const struct of_device_id of_gpio_fan_match
[] = {
534 { .compatible
= "gpio-fan", },
537 MODULE_DEVICE_TABLE(of
, of_gpio_fan_match
);
538 #endif /* CONFIG_OF_GPIO */
540 static int gpio_fan_probe(struct platform_device
*pdev
)
543 struct gpio_fan_data
*fan_data
;
544 struct gpio_fan_platform_data
*pdata
= dev_get_platdata(&pdev
->dev
);
546 fan_data
= devm_kzalloc(&pdev
->dev
, sizeof(struct gpio_fan_data
),
551 #ifdef CONFIG_OF_GPIO
553 pdata
= devm_kzalloc(&pdev
->dev
,
554 sizeof(struct gpio_fan_platform_data
),
559 err
= gpio_fan_get_of_pdata(&pdev
->dev
, pdata
);
563 #else /* CONFIG_OF_GPIO */
566 #endif /* CONFIG_OF_GPIO */
568 fan_data
->pdev
= pdev
;
569 platform_set_drvdata(pdev
, fan_data
);
570 mutex_init(&fan_data
->lock
);
572 /* Configure alarm GPIO if available. */
574 err
= fan_alarm_init(fan_data
, pdata
->alarm
);
579 /* Configure control GPIOs if available. */
580 if (pdata
->ctrl
&& pdata
->num_ctrl
> 0) {
581 if (!pdata
->speed
|| pdata
->num_speed
<= 1)
583 err
= fan_ctrl_init(fan_data
, pdata
);
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
,
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
,
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
,
605 #endif /* CONFIG_OF_GPIO */
607 dev_info(&pdev
->dev
, "GPIO fan initialized\n");
612 static int gpio_fan_remove(struct platform_device
*pdev
)
614 struct gpio_fan_data
*fan_data
= platform_get_drvdata(pdev
);
616 if (!IS_ERR(fan_data
->cdev
))
617 thermal_cooling_device_unregister(fan_data
->cdev
);
620 set_fan_speed(fan_data
, 0);
625 static void gpio_fan_shutdown(struct platform_device
*pdev
)
627 gpio_fan_remove(pdev
);
630 #ifdef CONFIG_PM_SLEEP
631 static int gpio_fan_suspend(struct device
*dev
)
633 struct gpio_fan_data
*fan_data
= dev_get_drvdata(dev
);
635 if (fan_data
->ctrl
) {
636 fan_data
->resume_speed
= fan_data
->speed_index
;
637 set_fan_speed(fan_data
, 0);
643 static int gpio_fan_resume(struct device
*dev
)
645 struct gpio_fan_data
*fan_data
= dev_get_drvdata(dev
);
648 set_fan_speed(fan_data
, fan_data
->resume_speed
);
653 static SIMPLE_DEV_PM_OPS(gpio_fan_pm
, gpio_fan_suspend
, gpio_fan_resume
);
654 #define GPIO_FAN_PM (&gpio_fan_pm)
656 #define GPIO_FAN_PM NULL
659 static struct platform_driver gpio_fan_driver
= {
660 .probe
= gpio_fan_probe
,
661 .remove
= gpio_fan_remove
,
662 .shutdown
= gpio_fan_shutdown
,
666 #ifdef CONFIG_OF_GPIO
667 .of_match_table
= of_match_ptr(of_gpio_fan_match
),
672 module_platform_driver(gpio_fan_driver
);
674 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
675 MODULE_DESCRIPTION("GPIO FAN driver");
676 MODULE_LICENSE("GPL");
677 MODULE_ALIAS("platform:gpio-fan");