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         unsigned long delay_on;         /* milliseconds on */
  29         unsigned long delay_off;        /* milliseconds off */
  30         struct timer_list timer;
  31 };
  32
  33 static void led_timer_function(unsigned long data)
  34 {
  35         struct led_classdev *led_cdev = (struct led_classdev *) data;
  36         struct timer_trig_data *timer_data = led_cdev->trigger_data;
  37         unsigned long brightness = LED_OFF;
  38         unsigned long delay = timer_data->delay_off;
  39
  40         if (!timer_data->delay_on || !timer_data->delay_off) {
  41                 led_set_brightness(led_cdev, LED_OFF);
  42                 return;
  43         }
  44
  45         if (!led_cdev->brightness) {
  46                 brightness = LED_FULL;
  47                 delay = timer_data->delay_on;
  48         }
  49
  50         led_set_brightness(led_cdev, brightness);
  51
  52         mod_timer(&timer_data->timer, jiffies + msecs_to_jiffies(delay));
  53 }
  54
  55 static ssize_t led_delay_on_show(struct class_device *dev, char *buf)
  56 {
  57         struct led_classdev *led_cdev = class_get_devdata(dev);
  58         struct timer_trig_data *timer_data = led_cdev->trigger_data;
  59
  60         sprintf(buf, "%lu\n", timer_data->delay_on);
  61
  62         return strlen(buf) + 1;
  63 }
  64
  65 static ssize_t led_delay_on_store(struct class_device *dev, const char *buf,
  66                                 size_t size)
  67 {
  68         struct led_classdev *led_cdev = class_get_devdata(dev);
  69         struct timer_trig_data *timer_data = led_cdev->trigger_data;
  70         int ret = -EINVAL;
  71         char *after;
  72         unsigned long state = simple_strtoul(buf, &after, 10);
  73         size_t count = after - buf;
  74
  75         if (*after && isspace(*after))
  76                 count++;
  77
  78         if (count == size) {
  79                 timer_data->delay_on = state;
  80                 mod_timer(&timer_data->timer, jiffies + 1);
  81                 ret = count;
  82         }
  83
  84         return ret;
  85 }
  86
  87 static ssize_t led_delay_off_show(struct class_device *dev, char *buf)
  88 {
  89         struct led_classdev *led_cdev = class_get_devdata(dev);
  90         struct timer_trig_data *timer_data = led_cdev->trigger_data;
  91
  92         sprintf(buf, "%lu\n", timer_data->delay_off);
  93
  94         return strlen(buf) + 1;
  95 }
  96
  97 static ssize_t led_delay_off_store(struct class_device *dev, const char *buf,
  98                                 size_t size)
  99 {
 100         struct led_classdev *led_cdev = class_get_devdata(dev);
 101         struct timer_trig_data *timer_data = led_cdev->trigger_data;
 102         int ret = -EINVAL;
 103         char *after;
 104         unsigned long state = simple_strtoul(buf, &after, 10);
 105         size_t count = after - buf;
 106
 107         if (*after && isspace(*after))
 108                 count++;
 109
 110         if (count == size) {
 111                 timer_data->delay_off = state;
 112                 mod_timer(&timer_data->timer, jiffies + 1);
 113                 ret = count;
 114         }
 115
 116         return ret;
 117 }
 118
 119 static CLASS_DEVICE_ATTR(delay_on, 0644, led_delay_on_show,
 120                         led_delay_on_store);
 121 static CLASS_DEVICE_ATTR(delay_off, 0644, led_delay_off_show,
 122                         led_delay_off_store);
 123
 124 static void timer_trig_activate(struct led_classdev *led_cdev)
 125 {
 126         struct timer_trig_data *timer_data;
 127         int rc;
 128
 129         timer_data = kzalloc(sizeof(struct timer_trig_data), GFP_KERNEL);
 130         if (!timer_data)
 131                 return;
 132
 133         led_cdev->trigger_data = timer_data;
 134
 135         init_timer(&timer_data->timer);
 136         timer_data->timer.function = led_timer_function;
 137         timer_data->timer.data = (unsigned long) led_cdev;
 138
 139         rc = class_device_create_file(led_cdev->class_dev,
 140                                 &class_device_attr_delay_on);
 141         if (rc) goto err_out;
 142         rc = class_device_create_file(led_cdev->class_dev,
 143                                 &class_device_attr_delay_off);
 144         if (rc) goto err_out_delayon;
 145
 146         return;
 147
 148 err_out_delayon:
 149         class_device_remove_file(led_cdev->class_dev,
 150                                 &class_device_attr_delay_on);
 151 err_out:
 152         led_cdev->trigger_data = NULL;
 153         kfree(timer_data);
 154 }
 155
 156 static void timer_trig_deactivate(struct led_classdev *led_cdev)
 157 {
 158         struct timer_trig_data *timer_data = led_cdev->trigger_data;
 159
 160         if (timer_data) {
 161                 class_device_remove_file(led_cdev->class_dev,
 162                                         &class_device_attr_delay_on);
 163                 class_device_remove_file(led_cdev->class_dev,
 164                                         &class_device_attr_delay_off);
 165                 del_timer_sync(&timer_data->timer);
 166                 kfree(timer_data);
 167         }
 168 }
 169
 170 static struct led_trigger timer_led_trigger = {
 171         .name     = "timer",
 172         .activate = timer_trig_activate,
 173         .deactivate = timer_trig_deactivate,
 174 };
 175
 176 static int __init timer_trig_init(void)
 177 {
 178         return led_trigger_register(&timer_led_trigger);
 179 }
 180
 181 static void __exit timer_trig_exit(void)
 182 {
 183         led_trigger_unregister(&timer_led_trigger);
 184 }
 185
 186 module_init(timer_trig_init);
 187 module_exit(timer_trig_exit);
 188
 189 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
 190 MODULE_DESCRIPTION("Timer LED trigger");
 191 MODULE_LICENSE("GPL");