38b3378be442b3d6501b8ffb9aa67e8eaba21ef4
[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/module.h>
15 #include <linux/jiffies.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/ctype.h>
24 #include <linux/leds.h>
25 #include "leds.h"
26
27 struct timer_trig_data {
28         int brightness_on;              /* LED brightness during "on" period.
29                                          * (LED_OFF < brightness_on <= LED_FULL)
30                                          */
31         unsigned long delay_on;         /* milliseconds on */
32         unsigned long delay_off;        /* milliseconds off */
33         struct timer_list timer;
34 };
35
36 static void led_timer_function(unsigned long data)
37 {
38         struct led_classdev *led_cdev = (struct led_classdev *) data;
39         struct timer_trig_data *timer_data = led_cdev->trigger_data;
40         unsigned long brightness;
41         unsigned long delay;
42
43         if (!timer_data->delay_on || !timer_data->delay_off) {
44                 led_set_brightness(led_cdev, LED_OFF);
45                 return;
46         }
47
48         brightness = led_get_brightness(led_cdev);
49         if (!brightness) {
50                 /* Time to switch the LED on. */
51                 brightness = timer_data->brightness_on;
52                 delay = timer_data->delay_on;
53         } else {
54                 /* Store the current brightness value to be able
55                  * to restore it when the delay_off period is over.
56                  */
57                 timer_data->brightness_on = brightness;
58                 brightness = LED_OFF;
59                 delay = timer_data->delay_off;
60         }
61
62         led_set_brightness(led_cdev, brightness);
63
64         mod_timer(&timer_data->timer, jiffies + msecs_to_jiffies(delay));
65 }
66
67 static ssize_t led_delay_on_show(struct device *dev,
68                 struct device_attribute *attr, char *buf)
69 {
70         struct led_classdev *led_cdev = dev_get_drvdata(dev);
71         struct timer_trig_data *timer_data = led_cdev->trigger_data;
72
73         return sprintf(buf, "%lu\n", timer_data->delay_on);
74 }
75
76 static ssize_t led_delay_on_store(struct device *dev,
77                 struct device_attribute *attr, const char *buf, size_t size)
78 {
79         struct led_classdev *led_cdev = dev_get_drvdata(dev);
80         struct timer_trig_data *timer_data = led_cdev->trigger_data;
81         int ret = -EINVAL;
82         char *after;
83         unsigned long state = simple_strtoul(buf, &after, 10);
84         size_t count = after - buf;
85
86         if (isspace(*after))
87                 count++;
88
89         if (count == size) {
90                 if (timer_data->delay_on != state) {
91                         /* the new value differs from the previous */
92                         timer_data->delay_on = state;
93
94                         /* deactivate previous settings */
95                         del_timer_sync(&timer_data->timer);
96
97                         /* try to activate hardware acceleration, if any */
98                         if (!led_cdev->blink_set ||
99                             led_cdev->blink_set(led_cdev,
100                               &timer_data->delay_on, &timer_data->delay_off)) {
101                                 /* no hardware acceleration, blink via timer */
102                                 mod_timer(&timer_data->timer, jiffies + 1);
103                         }
104                 }
105                 ret = count;
106         }
107
108         return ret;
109 }
110
111 static ssize_t led_delay_off_show(struct device *dev,
112                 struct device_attribute *attr, char *buf)
113 {
114         struct led_classdev *led_cdev = dev_get_drvdata(dev);
115         struct timer_trig_data *timer_data = led_cdev->trigger_data;
116
117         return sprintf(buf, "%lu\n", timer_data->delay_off);
118 }
119
120 static ssize_t led_delay_off_store(struct device *dev,
121                 struct device_attribute *attr, const char *buf, size_t size)
122 {
123         struct led_classdev *led_cdev = dev_get_drvdata(dev);
124         struct timer_trig_data *timer_data = led_cdev->trigger_data;
125         int ret = -EINVAL;
126         char *after;
127         unsigned long state = simple_strtoul(buf, &after, 10);
128         size_t count = after - buf;
129
130         if (isspace(*after))
131                 count++;
132
133         if (count == size) {
134                 if (timer_data->delay_off != state) {
135                         /* the new value differs from the previous */
136                         timer_data->delay_off = state;
137
138                         /* deactivate previous settings */
139                         del_timer_sync(&timer_data->timer);
140
141                         /* try to activate hardware acceleration, if any */
142                         if (!led_cdev->blink_set ||
143                             led_cdev->blink_set(led_cdev,
144                               &timer_data->delay_on, &timer_data->delay_off)) {
145                                 /* no hardware acceleration, blink via timer */
146                                 mod_timer(&timer_data->timer, jiffies + 1);
147                         }
148                 }
149                 ret = count;
150         }
151
152         return ret;
153 }
154
155 static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
156 static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
157
158 static void timer_trig_activate(struct led_classdev *led_cdev)
159 {
160         struct timer_trig_data *timer_data;
161         int rc;
162
163         timer_data = kzalloc(sizeof(struct timer_trig_data), GFP_KERNEL);
164         if (!timer_data)
165                 return;
166
167         timer_data->brightness_on = led_get_brightness(led_cdev);
168         if (timer_data->brightness_on == LED_OFF)
169                 timer_data->brightness_on = led_cdev->max_brightness;
170         led_cdev->trigger_data = timer_data;
171
172         init_timer(&timer_data->timer);
173         timer_data->timer.function = led_timer_function;
174         timer_data->timer.data = (unsigned long) led_cdev;
175
176         rc = device_create_file(led_cdev->dev, &dev_attr_delay_on);
177         if (rc)
178                 goto err_out;
179         rc = device_create_file(led_cdev->dev, &dev_attr_delay_off);
180         if (rc)
181                 goto err_out_delayon;
182
183         /* If there is hardware support for blinking, start one
184          * user friendly blink rate chosen by the driver.
185          */
186         if (led_cdev->blink_set)
187                 led_cdev->blink_set(led_cdev,
188                         &timer_data->delay_on, &timer_data->delay_off);
189
190         return;
191
192 err_out_delayon:
193         device_remove_file(led_cdev->dev, &dev_attr_delay_on);
194 err_out:
195         led_cdev->trigger_data = NULL;
196         kfree(timer_data);
197 }
198
199 static void timer_trig_deactivate(struct led_classdev *led_cdev)
200 {
201         struct timer_trig_data *timer_data = led_cdev->trigger_data;
202         unsigned long on = 0, off = 0;
203
204         if (timer_data) {
205                 device_remove_file(led_cdev->dev, &dev_attr_delay_on);
206                 device_remove_file(led_cdev->dev, &dev_attr_delay_off);
207                 del_timer_sync(&timer_data->timer);
208                 kfree(timer_data);
209         }
210
211         /* If there is hardware support for blinking, stop it */
212         if (led_cdev->blink_set)
213                 led_cdev->blink_set(led_cdev, &on, &off);
214 }
215
216 static struct led_trigger timer_led_trigger = {
217         .name     = "timer",
218         .activate = timer_trig_activate,
219         .deactivate = timer_trig_deactivate,
220 };
221
222 static int __init timer_trig_init(void)
223 {
224         return led_trigger_register(&timer_led_trigger);
225 }
226
227 static void __exit timer_trig_exit(void)
228 {
229         led_trigger_unregister(&timer_led_trigger);
230 }
231
232 module_init(timer_trig_init);
233 module_exit(timer_trig_exit);
234
235 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
236 MODULE_DESCRIPTION("Timer LED trigger");
237 MODULE_LICENSE("GPL");