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/timer.h>
19 #include <linux/err.h>
20 #include <linux/ctype.h>
21 #include <linux/leds.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
led_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
led_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
);
61 static ssize_t
led_max_brightness_show(struct device
*dev
,
62 struct device_attribute
*attr
, char *buf
)
64 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
66 return sprintf(buf
, "%u\n", led_cdev
->max_brightness
);
69 static struct device_attribute led_class_attrs
[] = {
70 __ATTR(brightness
, 0644, led_brightness_show
, led_brightness_store
),
71 __ATTR(max_brightness
, 0444, led_max_brightness_show
, NULL
),
72 #ifdef CONFIG_LEDS_TRIGGERS
73 __ATTR(trigger
, 0644, led_trigger_show
, led_trigger_store
),
78 static void led_timer_function(unsigned long data
)
80 struct led_classdev
*led_cdev
= (void *)data
;
81 unsigned long brightness
;
84 if (!led_cdev
->blink_delay_on
|| !led_cdev
->blink_delay_off
) {
85 __led_set_brightness(led_cdev
, LED_OFF
);
89 if (led_cdev
->flags
& LED_BLINK_ONESHOT_STOP
) {
90 led_cdev
->flags
&= ~LED_BLINK_ONESHOT_STOP
;
94 brightness
= led_get_brightness(led_cdev
);
96 /* Time to switch the LED on. */
97 brightness
= led_cdev
->blink_brightness
;
98 delay
= led_cdev
->blink_delay_on
;
100 /* Store the current brightness value to be able
101 * to restore it when the delay_off period is over.
103 led_cdev
->blink_brightness
= brightness
;
104 brightness
= LED_OFF
;
105 delay
= led_cdev
->blink_delay_off
;
108 __led_set_brightness(led_cdev
, brightness
);
110 /* Return in next iteration if led is in one-shot mode and we are in
111 * the final blink state so that the led is toggled each delay_on +
112 * delay_off milliseconds in worst case.
114 if (led_cdev
->flags
& LED_BLINK_ONESHOT
) {
115 if (led_cdev
->flags
& LED_BLINK_INVERT
) {
117 led_cdev
->flags
|= LED_BLINK_ONESHOT_STOP
;
120 led_cdev
->flags
|= LED_BLINK_ONESHOT_STOP
;
124 mod_timer(&led_cdev
->blink_timer
, jiffies
+ msecs_to_jiffies(delay
));
128 * led_classdev_suspend - suspend an led_classdev.
129 * @led_cdev: the led_classdev to suspend.
131 void led_classdev_suspend(struct led_classdev
*led_cdev
)
133 led_cdev
->flags
|= LED_SUSPENDED
;
134 led_cdev
->brightness_set(led_cdev
, 0);
136 EXPORT_SYMBOL_GPL(led_classdev_suspend
);
139 * led_classdev_resume - resume an led_classdev.
140 * @led_cdev: the led_classdev to resume.
142 void led_classdev_resume(struct led_classdev
*led_cdev
)
144 led_cdev
->brightness_set(led_cdev
, led_cdev
->brightness
);
145 led_cdev
->flags
&= ~LED_SUSPENDED
;
147 EXPORT_SYMBOL_GPL(led_classdev_resume
);
149 static int led_suspend(struct device
*dev
, pm_message_t state
)
151 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
153 if (led_cdev
->flags
& LED_CORE_SUSPENDRESUME
)
154 led_classdev_suspend(led_cdev
);
159 static int led_resume(struct device
*dev
)
161 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
163 if (led_cdev
->flags
& LED_CORE_SUSPENDRESUME
)
164 led_classdev_resume(led_cdev
);
170 * led_classdev_register - register a new object of led_classdev class.
171 * @parent: The device to register.
172 * @led_cdev: the led_classdev structure for this device.
174 int led_classdev_register(struct device
*parent
, struct led_classdev
*led_cdev
)
176 led_cdev
->dev
= device_create(leds_class
, parent
, 0, led_cdev
,
177 "%s", led_cdev
->name
);
178 if (IS_ERR(led_cdev
->dev
))
179 return PTR_ERR(led_cdev
->dev
);
181 #ifdef CONFIG_LEDS_TRIGGERS
182 init_rwsem(&led_cdev
->trigger_lock
);
184 /* add to the list of leds */
185 down_write(&leds_list_lock
);
186 list_add_tail(&led_cdev
->node
, &leds_list
);
187 up_write(&leds_list_lock
);
189 if (!led_cdev
->max_brightness
)
190 led_cdev
->max_brightness
= LED_FULL
;
192 led_update_brightness(led_cdev
);
194 init_timer(&led_cdev
->blink_timer
);
195 led_cdev
->blink_timer
.function
= led_timer_function
;
196 led_cdev
->blink_timer
.data
= (unsigned long)led_cdev
;
198 #ifdef CONFIG_LEDS_TRIGGERS
199 led_trigger_set_default(led_cdev
);
202 printk(KERN_DEBUG
"Registered led device: %s\n",
207 EXPORT_SYMBOL_GPL(led_classdev_register
);
210 * led_classdev_unregister - unregisters a object of led_properties class.
211 * @led_cdev: the led device to unregister
213 * Unregisters a previously registered via led_classdev_register object.
215 void led_classdev_unregister(struct led_classdev
*led_cdev
)
217 #ifdef CONFIG_LEDS_TRIGGERS
218 down_write(&led_cdev
->trigger_lock
);
219 if (led_cdev
->trigger
)
220 led_trigger_set(led_cdev
, NULL
);
221 up_write(&led_cdev
->trigger_lock
);
225 led_set_brightness(led_cdev
, LED_OFF
);
227 device_unregister(led_cdev
->dev
);
229 down_write(&leds_list_lock
);
230 list_del(&led_cdev
->node
);
231 up_write(&leds_list_lock
);
233 EXPORT_SYMBOL_GPL(led_classdev_unregister
);
235 static int __init
leds_init(void)
237 leds_class
= class_create(THIS_MODULE
, "leds");
238 if (IS_ERR(leds_class
))
239 return PTR_ERR(leds_class
);
240 leds_class
->suspend
= led_suspend
;
241 leds_class
->resume
= led_resume
;
242 leds_class
->dev_attrs
= led_class_attrs
;
246 static void __exit
leds_exit(void)
248 class_destroy(leds_class
);
251 subsys_initcall(leds_init
);
252 module_exit(leds_exit
);
254 MODULE_AUTHOR("John Lenz, Richard Purdie");
255 MODULE_LICENSE("GPL");
256 MODULE_DESCRIPTION("LED Class Interface");