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/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/list.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/device.h>
  20 #include <linux/sysdev.h>
  21 #include <linux/timer.h>
  22 #include <linux/ctype.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         size_t count = after - buf;
  73
  74         if (*after && isspace(*after))
  75                 count++;
  76
  77         if (count == size) {
  78                 timer_data->delay_on = state;
  79                 mod_timer(&timer_data->timer, jiffies + 1);
  80                 ret = count;
  81         }
  82
  83         return ret;
  84 }
  85
  86 static ssize_t led_delay_off_show(struct class_device *dev, char *buf)
  87 {
  88         struct led_classdev *led_cdev = class_get_devdata(dev);
  89         struct timer_trig_data *timer_data = led_cdev->trigger_data;
  90
  91         sprintf(buf, "%lu\n", timer_data->delay_off);
  92
  93         return strlen(buf) + 1;
  94 }
  95
  96 static ssize_t led_delay_off_store(struct class_device *dev, const char *buf,
  97                                 size_t size)
  98 {
  99         struct led_classdev *led_cdev = class_get_devdata(dev);
 100         struct timer_trig_data *timer_data = led_cdev->trigger_data;
 101         int ret = -EINVAL;
 102         char *after;
 103         unsigned long state = simple_strtoul(buf, &after, 10);
 104         size_t count = after - buf;
 105
 106         if (*after && isspace(*after))
 107                 count++;
 108
 109         if (count == size) {
 110                 timer_data->delay_off = state;
 111                 mod_timer(&timer_data->timer, jiffies + 1);
 112                 ret = count;
 113         }
 114
 115         return ret;
 116 }
 117
 118 static CLASS_DEVICE_ATTR(delay_on, 0644, led_delay_on_show,
 119                         led_delay_on_store);
 120 static CLASS_DEVICE_ATTR(delay_off, 0644, led_delay_off_show,
 121                         led_delay_off_store);
 122
 123 static void timer_trig_activate(struct led_classdev *led_cdev)
 124 {
 125         struct timer_trig_data *timer_data;
 126
 127         timer_data = kzalloc(sizeof(struct timer_trig_data), GFP_KERNEL);
 128         if (!timer_data)
 129                 return;
 130
 131         led_cdev->trigger_data = timer_data;
 132
 133         init_timer(&timer_data->timer);
 134         timer_data->timer.function = led_timer_function;
 135         timer_data->timer.data = (unsigned long) led_cdev;
 136
 137         class_device_create_file(led_cdev->class_dev,
 138                                 &class_device_attr_delay_on);
 139         class_device_create_file(led_cdev->class_dev,
 140                                 &class_device_attr_delay_off);
 141 }
 142
 143 static void timer_trig_deactivate(struct led_classdev *led_cdev)
 144 {
 145         struct timer_trig_data *timer_data = led_cdev->trigger_data;
 146
 147         if (timer_data) {
 148                 class_device_remove_file(led_cdev->class_dev,
 149                                         &class_device_attr_delay_on);
 150                 class_device_remove_file(led_cdev->class_dev,
 151                                         &class_device_attr_delay_off);
 152                 del_timer_sync(&timer_data->timer);
 153                 kfree(timer_data);
 154         }
 155 }
 156
 157 static struct led_trigger timer_led_trigger = {
 158         .name     = "timer",
 159         .activate = timer_trig_activate,
 160         .deactivate = timer_trig_deactivate,
 161 };
 162
 163 static int __init timer_trig_init(void)
 164 {
 165         return led_trigger_register(&timer_led_trigger);
 166 }
 167
 168 static void __exit timer_trig_exit(void)
 169 {
 170         led_trigger_unregister(&timer_led_trigger);
 171 }
 172
 173 module_init(timer_trig_init);
 174 module_exit(timer_trig_exit);
 175
 176 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
 177 MODULE_DESCRIPTION("Timer LED trigger");
 178 MODULE_LICENSE("GPL");