4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
5 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/list.h>
16 #include <linux/spinlock.h>
17 #include <linux/device.h>
18 #include <linux/err.h>
19 #include <linux/ctype.h>
20 #include <linux/leds.h>
21 #include <linux/workqueue.h>
24 static struct class *leds_class
;
26 static void led_update_brightness(struct led_classdev
*led_cdev
)
28 if (led_cdev
->brightness_get
)
29 led_cdev
->brightness
= led_cdev
->brightness_get(led_cdev
);
32 static ssize_t
brightness_show(struct device
*dev
,
33 struct device_attribute
*attr
, char *buf
)
35 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
37 /* no lock needed for this */
38 led_update_brightness(led_cdev
);
40 return sprintf(buf
, "%u\n", led_cdev
->brightness
);
43 static ssize_t
brightness_store(struct device
*dev
,
44 struct device_attribute
*attr
, const char *buf
, size_t size
)
46 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
48 ssize_t ret
= -EINVAL
;
50 ret
= kstrtoul(buf
, 10, &state
);
55 led_trigger_remove(led_cdev
);
56 __led_set_brightness(led_cdev
, state
);
60 static DEVICE_ATTR_RW(brightness
);
62 static ssize_t
led_max_brightness_show(struct device
*dev
,
63 struct device_attribute
*attr
, char *buf
)
65 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
67 return sprintf(buf
, "%u\n", led_cdev
->max_brightness
);
69 static DEVICE_ATTR(max_brightness
, 0444, led_max_brightness_show
, NULL
);
71 #ifdef CONFIG_LEDS_TRIGGERS
72 static DEVICE_ATTR(trigger
, 0644, led_trigger_show
, led_trigger_store
);
73 static struct attribute
*led_trigger_attrs
[] = {
74 &dev_attr_trigger
.attr
,
77 static const struct attribute_group led_trigger_group
= {
78 .attrs
= led_trigger_attrs
,
82 static struct attribute
*led_class_attrs
[] = {
83 &dev_attr_brightness
.attr
,
84 &dev_attr_max_brightness
.attr
,
88 static const struct attribute_group led_group
= {
89 .attrs
= led_class_attrs
,
92 static const struct attribute_group
*led_groups
[] = {
94 #ifdef CONFIG_LEDS_TRIGGERS
100 static void led_work_function(struct work_struct
*ws
)
102 struct led_classdev
*led_cdev
=
103 container_of(ws
, struct led_classdev
, blink_work
.work
);
104 unsigned long brightness
;
107 if (!led_cdev
->blink_delay_on
|| !led_cdev
->blink_delay_off
) {
108 __led_set_brightness(led_cdev
, LED_OFF
);
112 if (led_cdev
->flags
& LED_BLINK_ONESHOT_STOP
) {
113 led_cdev
->flags
&= ~LED_BLINK_ONESHOT_STOP
;
117 brightness
= led_get_brightness(led_cdev
);
119 /* Time to switch the LED on. */
120 brightness
= led_cdev
->blink_brightness
;
121 delay
= led_cdev
->blink_delay_on
;
123 /* Store the current brightness value to be able
124 * to restore it when the delay_off period is over.
126 led_cdev
->blink_brightness
= brightness
;
127 brightness
= LED_OFF
;
128 delay
= led_cdev
->blink_delay_off
;
131 __led_set_brightness(led_cdev
, brightness
);
133 /* Return in next iteration if led is in one-shot mode and we are in
134 * the final blink state so that the led is toggled each delay_on +
135 * delay_off milliseconds in worst case.
137 if (led_cdev
->flags
& LED_BLINK_ONESHOT
) {
138 if (led_cdev
->flags
& LED_BLINK_INVERT
) {
140 led_cdev
->flags
|= LED_BLINK_ONESHOT_STOP
;
143 led_cdev
->flags
|= LED_BLINK_ONESHOT_STOP
;
147 queue_delayed_work(system_wq
, &led_cdev
->blink_work
,
148 msecs_to_jiffies(delay
));
151 static void set_brightness_delayed(struct work_struct
*ws
)
153 struct led_classdev
*led_cdev
=
154 container_of(ws
, struct led_classdev
, set_brightness_work
);
156 led_stop_software_blink(led_cdev
);
158 __led_set_brightness(led_cdev
, led_cdev
->delayed_set_value
);
162 * led_classdev_suspend - suspend an led_classdev.
163 * @led_cdev: the led_classdev to suspend.
165 void led_classdev_suspend(struct led_classdev
*led_cdev
)
167 led_cdev
->flags
|= LED_SUSPENDED
;
168 led_cdev
->brightness_set(led_cdev
, 0);
170 EXPORT_SYMBOL_GPL(led_classdev_suspend
);
173 * led_classdev_resume - resume an led_classdev.
174 * @led_cdev: the led_classdev to resume.
176 void led_classdev_resume(struct led_classdev
*led_cdev
)
178 led_cdev
->brightness_set(led_cdev
, led_cdev
->brightness
);
179 led_cdev
->flags
&= ~LED_SUSPENDED
;
181 EXPORT_SYMBOL_GPL(led_classdev_resume
);
183 static int led_suspend(struct device
*dev
)
185 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
187 if (led_cdev
->flags
& LED_CORE_SUSPENDRESUME
)
188 led_classdev_suspend(led_cdev
);
193 static int led_resume(struct device
*dev
)
195 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
197 if (led_cdev
->flags
& LED_CORE_SUSPENDRESUME
)
198 led_classdev_resume(led_cdev
);
203 static const struct dev_pm_ops leds_class_dev_pm_ops
= {
204 .suspend
= led_suspend
,
205 .resume
= led_resume
,
209 * led_classdev_register - register a new object of led_classdev class.
210 * @parent: The device to register.
211 * @led_cdev: the led_classdev structure for this device.
213 int led_classdev_register(struct device
*parent
, struct led_classdev
*led_cdev
)
215 led_cdev
->dev
= device_create_with_groups(leds_class
, parent
, 0,
216 led_cdev
, led_cdev
->groups
,
217 "%s", led_cdev
->name
);
218 if (IS_ERR(led_cdev
->dev
))
219 return PTR_ERR(led_cdev
->dev
);
221 #ifdef CONFIG_LEDS_TRIGGERS
222 init_rwsem(&led_cdev
->trigger_lock
);
224 /* add to the list of leds */
225 down_write(&leds_list_lock
);
226 list_add_tail(&led_cdev
->node
, &leds_list
);
227 up_write(&leds_list_lock
);
229 if (!led_cdev
->max_brightness
)
230 led_cdev
->max_brightness
= LED_FULL
;
232 led_update_brightness(led_cdev
);
234 INIT_WORK(&led_cdev
->set_brightness_work
, set_brightness_delayed
);
236 INIT_DELAYED_WORK(&led_cdev
->blink_work
, led_work_function
);
238 #ifdef CONFIG_LEDS_TRIGGERS
239 led_trigger_set_default(led_cdev
);
242 dev_dbg(parent
, "Registered led device: %s\n",
247 EXPORT_SYMBOL_GPL(led_classdev_register
);
250 * led_classdev_unregister - unregisters a object of led_properties class.
251 * @led_cdev: the led device to unregister
253 * Unregisters a previously registered via led_classdev_register object.
255 void led_classdev_unregister(struct led_classdev
*led_cdev
)
257 #ifdef CONFIG_LEDS_TRIGGERS
258 down_write(&led_cdev
->trigger_lock
);
259 if (led_cdev
->trigger
)
260 led_trigger_set(led_cdev
, NULL
);
261 up_write(&led_cdev
->trigger_lock
);
264 cancel_work_sync(&led_cdev
->set_brightness_work
);
267 led_stop_software_blink(led_cdev
);
268 led_set_brightness(led_cdev
, LED_OFF
);
270 device_unregister(led_cdev
->dev
);
272 down_write(&leds_list_lock
);
273 list_del(&led_cdev
->node
);
274 up_write(&leds_list_lock
);
276 EXPORT_SYMBOL_GPL(led_classdev_unregister
);
278 static int __init
leds_init(void)
280 leds_class
= class_create(THIS_MODULE
, "leds");
281 if (IS_ERR(leds_class
))
282 return PTR_ERR(leds_class
);
283 leds_class
->pm
= &leds_class_dev_pm_ops
;
284 leds_class
->dev_groups
= led_groups
;
288 static void __exit
leds_exit(void)
290 class_destroy(leds_class
);
293 subsys_initcall(leds_init
);
294 module_exit(leds_exit
);
296 MODULE_AUTHOR("John Lenz, Richard Purdie");
297 MODULE_LICENSE("GPL");
298 MODULE_DESCRIPTION("LED Class Interface");