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 device *dev,
  56                 struct device_attribute *attr, char *buf)
  57 {
  58         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  59         struct timer_trig_data *timer_data = led_cdev->trigger_data;
  60
  61         sprintf(buf, "%lu\n", timer_data->delay_on);
  62
  63         return strlen(buf) + 1;
  64 }
  65
  66 static ssize_t led_delay_on_store(struct device *dev,
  67                 struct device_attribute *attr, const char *buf, size_t size)
  68 {
  69         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  70         struct timer_trig_data *timer_data = led_cdev->trigger_data;
  71         int ret = -EINVAL;
  72         char *after;
  73         unsigned long state = simple_strtoul(buf, &after, 10);
  74         size_t count = after - buf;
  75
  76         if (*after && isspace(*after))
  77                 count++;
  78
  79         if (count == size) {
  80                 timer_data->delay_on = state;
  81                 mod_timer(&timer_data->timer, jiffies + 1);
  82                 ret = count;
  83         }
  84
  85         return ret;
  86 }
  87
  88 static ssize_t led_delay_off_show(struct device *dev,
  89                 struct device_attribute *attr, char *buf)
  90 {
  91         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  92         struct timer_trig_data *timer_data = led_cdev->trigger_data;
  93
  94         sprintf(buf, "%lu\n", timer_data->delay_off);
  95
  96         return strlen(buf) + 1;
  97 }
  98
  99 static ssize_t led_delay_off_store(struct device *dev,
 100                 struct device_attribute *attr, const char *buf, size_t size)
 101 {
 102         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 103         struct timer_trig_data *timer_data = led_cdev->trigger_data;
 104         int ret = -EINVAL;
 105         char *after;
 106         unsigned long state = simple_strtoul(buf, &after, 10);
 107         size_t count = after - buf;
 108
 109         if (*after && isspace(*after))
 110                 count++;
 111
 112         if (count == size) {
 113                 timer_data->delay_off = state;
 114                 mod_timer(&timer_data->timer, jiffies + 1);
 115                 ret = count;
 116         }
 117
 118         return ret;
 119 }
 120
 121 static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
 122 static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, 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 = device_create_file(led_cdev->dev, &dev_attr_delay_on);
 140         if (rc)
 141                 goto err_out;
 142         rc = device_create_file(led_cdev->dev, &dev_attr_delay_off);
 143         if (rc)
 144                 goto err_out_delayon;
 145
 146         return;
 147
 148 err_out_delayon:
 149         device_remove_file(led_cdev->dev, &dev_attr_delay_on);
 150 err_out:
 151         led_cdev->trigger_data = NULL;
 152         kfree(timer_data);
 153 }
 154
 155 static void timer_trig_deactivate(struct led_classdev *led_cdev)
 156 {
 157         struct timer_trig_data *timer_data = led_cdev->trigger_data;
 158
 159         if (timer_data) {
 160                 device_remove_file(led_cdev->dev, &dev_attr_delay_on);
 161                 device_remove_file(led_cdev->dev, &dev_attr_delay_off);
 162                 del_timer_sync(&timer_data->timer);
 163                 kfree(timer_data);
 164         }
 165 }
 166
 167 static struct led_trigger timer_led_trigger = {
 168         .name     = "timer",
 169         .activate = timer_trig_activate,
 170         .deactivate = timer_trig_deactivate,
 171 };
 172
 173 static int __init timer_trig_init(void)
 174 {
 175         return led_trigger_register(&timer_led_trigger);
 176 }
 177
 178 static void __exit timer_trig_exit(void)
 179 {
 180         led_trigger_unregister(&timer_led_trigger);
 181 }
 182
 183 module_init(timer_trig_init);
 184 module_exit(timer_trig_exit);
 185
 186 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
 187 MODULE_DESCRIPTION("Timer LED trigger");
 188 MODULE_LICENSE("GPL");