kernel/drivers/leds/trigger/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/device.h>
  18 #include <linux/ctype.h>
  19 #include <linux/leds.h>
  20
  21 static ssize_t led_delay_on_show(struct device *dev,
  22                 struct device_attribute *attr, char *buf)
  23 {
  24         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  25
  26         return sprintf(buf, "%lu\n", led_cdev->blink_delay_on);
  27 }
  28
  29 static ssize_t led_delay_on_store(struct device *dev,
  30                 struct device_attribute *attr, const char *buf, size_t size)
  31 {
  32         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  33         unsigned long state;
  34         ssize_t ret = -EINVAL;
  35
  36         ret = kstrtoul(buf, 10, &state);
  37         if (ret)
  38                 return ret;
  39
  40         led_blink_set(led_cdev, &state, &led_cdev->blink_delay_off);
  41         led_cdev->blink_delay_on = state;
  42
  43         return size;
  44 }
  45
  46 static ssize_t led_delay_off_show(struct device *dev,
  47                 struct device_attribute *attr, char *buf)
  48 {
  49         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  50
  51         return sprintf(buf, "%lu\n", led_cdev->blink_delay_off);
  52 }
  53
  54 static ssize_t led_delay_off_store(struct device *dev,
  55                 struct device_attribute *attr, const char *buf, size_t size)
  56 {
  57         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  58         unsigned long state;
  59         ssize_t ret = -EINVAL;
  60
  61         ret = kstrtoul(buf, 10, &state);
  62         if (ret)
  63                 return ret;
  64
  65         led_blink_set(led_cdev, &led_cdev->blink_delay_on, &state);
  66         led_cdev->blink_delay_off = state;
  67
  68         return size;
  69 }
  70
  71 static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
  72 static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
  73
  74 static void timer_trig_activate(struct led_classdev *led_cdev)
  75 {
  76         int rc;
  77
  78         led_cdev->trigger_data = NULL;
  79
  80         rc = device_create_file(led_cdev->dev, &dev_attr_delay_on);
  81         if (rc)
  82                 return;
  83         rc = device_create_file(led_cdev->dev, &dev_attr_delay_off);
  84         if (rc)
  85                 goto err_out_delayon;
  86
  87         led_blink_set(led_cdev, &led_cdev->blink_delay_on,
  88                       &led_cdev->blink_delay_off);
  89         led_cdev->activated = true;
  90
  91         return;
  92
  93 err_out_delayon:
  94         device_remove_file(led_cdev->dev, &dev_attr_delay_on);
  95 }
  96
  97 static void timer_trig_deactivate(struct led_classdev *led_cdev)
  98 {
  99         if (led_cdev->activated) {
 100                 device_remove_file(led_cdev->dev, &dev_attr_delay_on);
 101                 device_remove_file(led_cdev->dev, &dev_attr_delay_off);
 102                 led_cdev->activated = false;
 103         }
 104
 105         /* Stop blinking */
 106         led_set_brightness(led_cdev, LED_OFF);
 107 }
 108
 109 static struct led_trigger timer_led_trigger = {
 110         .name     = "timer",
 111         .activate = timer_trig_activate,
 112         .deactivate = timer_trig_deactivate,
 113 };
 114
 115 static int __init timer_trig_init(void)
 116 {
 117         return led_trigger_register(&timer_led_trigger);
 118 }
 119
 120 static void __exit timer_trig_exit(void)
 121 {
 122         led_trigger_unregister(&timer_led_trigger);
 123 }
 124
 125 module_init(timer_trig_init);
 126 module_exit(timer_trig_exit);
 127
 128 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
 129 MODULE_DESCRIPTION("Timer LED trigger");
 130 MODULE_LICENSE("GPL");