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 brightness
= led_get_brightness(led_cdev
);
91 /* Time to switch the LED on. */
92 brightness
= led_cdev
->blink_brightness
;
93 delay
= led_cdev
->blink_delay_on
;
95 /* Store the current brightness value to be able
96 * to restore it when the delay_off period is over.
98 led_cdev
->blink_brightness
= brightness
;
100 delay
= led_cdev
->blink_delay_off
;
103 led_set_brightness(led_cdev
, brightness
);
105 mod_timer(&led_cdev
->blink_timer
, jiffies
+ msecs_to_jiffies(delay
));
109 * led_classdev_suspend - suspend an led_classdev.
110 * @led_cdev: the led_classdev to suspend.
112 void led_classdev_suspend(struct led_classdev
*led_cdev
)
114 led_cdev
->flags
|= LED_SUSPENDED
;
115 led_cdev
->brightness_set(led_cdev
, 0);
117 EXPORT_SYMBOL_GPL(led_classdev_suspend
);
120 * led_classdev_resume - resume an led_classdev.
121 * @led_cdev: the led_classdev to resume.
123 void led_classdev_resume(struct led_classdev
*led_cdev
)
125 led_cdev
->brightness_set(led_cdev
, led_cdev
->brightness
);
126 led_cdev
->flags
&= ~LED_SUSPENDED
;
128 EXPORT_SYMBOL_GPL(led_classdev_resume
);
130 static int led_suspend(struct device
*dev
, pm_message_t state
)
132 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
134 if (led_cdev
->flags
& LED_CORE_SUSPENDRESUME
)
135 led_classdev_suspend(led_cdev
);
140 static int led_resume(struct device
*dev
)
142 struct led_classdev
*led_cdev
= dev_get_drvdata(dev
);
144 if (led_cdev
->flags
& LED_CORE_SUSPENDRESUME
)
145 led_classdev_resume(led_cdev
);
151 * led_classdev_register - register a new object of led_classdev class.
152 * @parent: The device to register.
153 * @led_cdev: the led_classdev structure for this device.
155 int led_classdev_register(struct device
*parent
, struct led_classdev
*led_cdev
)
157 led_cdev
->dev
= device_create(leds_class
, parent
, 0, led_cdev
,
158 "%s", led_cdev
->name
);
159 if (IS_ERR(led_cdev
->dev
))
160 return PTR_ERR(led_cdev
->dev
);
162 #ifdef CONFIG_LEDS_TRIGGERS
163 init_rwsem(&led_cdev
->trigger_lock
);
165 /* add to the list of leds */
166 down_write(&leds_list_lock
);
167 list_add_tail(&led_cdev
->node
, &leds_list
);
168 up_write(&leds_list_lock
);
170 if (!led_cdev
->max_brightness
)
171 led_cdev
->max_brightness
= LED_FULL
;
173 led_update_brightness(led_cdev
);
175 init_timer(&led_cdev
->blink_timer
);
176 led_cdev
->blink_timer
.function
= led_timer_function
;
177 led_cdev
->blink_timer
.data
= (unsigned long)led_cdev
;
179 #ifdef CONFIG_LEDS_TRIGGERS
180 led_trigger_set_default(led_cdev
);
183 printk(KERN_DEBUG
"Registered led device: %s\n",
188 EXPORT_SYMBOL_GPL(led_classdev_register
);
191 * led_classdev_unregister - unregisters a object of led_properties class.
192 * @led_cdev: the led device to unregister
194 * Unregisters a previously registered via led_classdev_register object.
196 void led_classdev_unregister(struct led_classdev
*led_cdev
)
198 #ifdef CONFIG_LEDS_TRIGGERS
199 down_write(&led_cdev
->trigger_lock
);
200 if (led_cdev
->trigger
)
201 led_trigger_set(led_cdev
, NULL
);
202 up_write(&led_cdev
->trigger_lock
);
206 led_brightness_set(led_cdev
, LED_OFF
);
208 device_unregister(led_cdev
->dev
);
210 down_write(&leds_list_lock
);
211 list_del(&led_cdev
->node
);
212 up_write(&leds_list_lock
);
214 EXPORT_SYMBOL_GPL(led_classdev_unregister
);
216 static int __init
leds_init(void)
218 leds_class
= class_create(THIS_MODULE
, "leds");
219 if (IS_ERR(leds_class
))
220 return PTR_ERR(leds_class
);
221 leds_class
->suspend
= led_suspend
;
222 leds_class
->resume
= led_resume
;
223 leds_class
->dev_attrs
= led_class_attrs
;
227 static void __exit
leds_exit(void)
229 class_destroy(leds_class
);
232 subsys_initcall(leds_init
);
233 module_exit(leds_exit
);
235 MODULE_AUTHOR("John Lenz, Richard Purdie");
236 MODULE_LICENSE("GPL");
237 MODULE_DESCRIPTION("LED Class Interface");