[PATCH] LED: Improve Kconfig information
[linux-2.6.git] / drivers / leds / ledtrig-timer.c
1 /*
2  * LED Kernel Timer Trigger
3  *
4  * Copyright 2005-2006 Openedhand Ltd.
5  *
6  * Author: Richard Purdie <rpurdie@openedhand.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 version 2 as
10  * published by the Free Software Foundation.
11  *
12  */
13
14 #include <linux/config.h>
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/list.h>
19 #include <linux/spinlock.h>
20 #include <linux/device.h>
21 #include <linux/sysdev.h>
22 #include <linux/timer.h>
23 #include <linux/leds.h>
24 #include "leds.h"
25
26 struct timer_trig_data {
27         unsigned long delay_on;         /* milliseconds on */
28         unsigned long delay_off;        /* milliseconds off */
29         struct timer_list timer;
30 };
31
32 static void led_timer_function(unsigned long data)
33 {
34         struct led_classdev *led_cdev = (struct led_classdev *) data;
35         struct timer_trig_data *timer_data = led_cdev->trigger_data;
36         unsigned long brightness = LED_OFF;
37         unsigned long delay = timer_data->delay_off;
38
39         if (!timer_data->delay_on || !timer_data->delay_off) {
40                 led_set_brightness(led_cdev, LED_OFF);
41                 return;
42         }
43
44         if (!led_cdev->brightness) {
45                 brightness = LED_FULL;
46                 delay = timer_data->delay_on;
47         }
48
49         led_set_brightness(led_cdev, brightness);
50
51         mod_timer(&timer_data->timer, jiffies + msecs_to_jiffies(delay));
52 }
53
54 static ssize_t led_delay_on_show(struct class_device *dev, char *buf)
55 {
56         struct led_classdev *led_cdev = class_get_devdata(dev);
57         struct timer_trig_data *timer_data = led_cdev->trigger_data;
58
59         sprintf(buf, "%lu\n", timer_data->delay_on);
60
61         return strlen(buf) + 1;
62 }
63
64 static ssize_t led_delay_on_store(struct class_device *dev, const char *buf,
65                                 size_t size)
66 {
67         struct led_classdev *led_cdev = class_get_devdata(dev);
68         struct timer_trig_data *timer_data = led_cdev->trigger_data;
69         int ret = -EINVAL;
70         char *after;
71         unsigned long state = simple_strtoul(buf, &after, 10);
72
73         if (after - buf > 0) {
74                 timer_data->delay_on = state;
75                 mod_timer(&timer_data->timer, jiffies + 1);
76                 ret = after - buf;
77         }
78
79         return ret;
80 }
81
82 static ssize_t led_delay_off_show(struct class_device *dev, char *buf)
83 {
84         struct led_classdev *led_cdev = class_get_devdata(dev);
85         struct timer_trig_data *timer_data = led_cdev->trigger_data;
86
87         sprintf(buf, "%lu\n", timer_data->delay_off);
88
89         return strlen(buf) + 1;
90 }
91
92 static ssize_t led_delay_off_store(struct class_device *dev, const char *buf,
93                                 size_t size)
94 {
95         struct led_classdev *led_cdev = class_get_devdata(dev);
96         struct timer_trig_data *timer_data = led_cdev->trigger_data;
97         int ret = -EINVAL;
98         char *after;
99         unsigned long state = simple_strtoul(buf, &after, 10);
100
101         if (after - buf > 0) {
102                 timer_data->delay_off = state;
103                 mod_timer(&timer_data->timer, jiffies + 1);
104                 ret = after - buf;
105         }
106
107         return ret;
108 }
109
110 static CLASS_DEVICE_ATTR(delay_on, 0644, led_delay_on_show,
111                         led_delay_on_store);
112 static CLASS_DEVICE_ATTR(delay_off, 0644, led_delay_off_show,
113                         led_delay_off_store);
114
115 static void timer_trig_activate(struct led_classdev *led_cdev)
116 {
117         struct timer_trig_data *timer_data;
118
119         timer_data = kzalloc(sizeof(struct timer_trig_data), GFP_KERNEL);
120         if (!timer_data)
121                 return;
122
123         led_cdev->trigger_data = timer_data;
124
125         init_timer(&timer_data->timer);
126         timer_data->timer.function = led_timer_function;
127         timer_data->timer.data = (unsigned long) led_cdev;
128
129         class_device_create_file(led_cdev->class_dev,
130                                 &class_device_attr_delay_on);
131         class_device_create_file(led_cdev->class_dev,
132                                 &class_device_attr_delay_off);
133 }
134
135 static void timer_trig_deactivate(struct led_classdev *led_cdev)
136 {
137         struct timer_trig_data *timer_data = led_cdev->trigger_data;
138
139         if (timer_data) {
140                 class_device_remove_file(led_cdev->class_dev,
141                                         &class_device_attr_delay_on);
142                 class_device_remove_file(led_cdev->class_dev,
143                                         &class_device_attr_delay_off);
144                 del_timer_sync(&timer_data->timer);
145                 kfree(timer_data);
146         }
147 }
148
149 static struct led_trigger timer_led_trigger = {
150         .name     = "timer",
151         .activate = timer_trig_activate,
152         .deactivate = timer_trig_deactivate,
153 };
154
155 static int __init timer_trig_init(void)
156 {
157         return led_trigger_register(&timer_led_trigger);
158 }
159
160 static void __exit timer_trig_exit(void)
161 {
162         led_trigger_unregister(&timer_led_trigger);
163 }
164
165 module_init(timer_trig_init);
166 module_exit(timer_trig_exit);
167
168 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
169 MODULE_DESCRIPTION("Timer LED trigger");
170 MODULE_LICENSE("GPL");