drivers/leds/trigger/ledtrig-timer.c

   1 /*
   2  * LED Kernel Timer Trigger
   3  *
   4  * Copyright 2005-2006 Openedhand Ltd.
   5  *
   6  * Author: Richard Purdie <[email protected]>
   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 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/device.h>
  17 #include <linux/ctype.h>
  18 #include <linux/slab.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 = led_trigger_get_led(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 = led_trigger_get_led(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 = led_trigger_get_led(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 = led_trigger_get_led(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 struct attribute *timer_trig_attrs[] = {
  75         &dev_attr_delay_on.attr,
  76         &dev_attr_delay_off.attr,
  77         NULL
  78 };
  79 ATTRIBUTE_GROUPS(timer_trig);
  80
  81 static void pattern_init(struct led_classdev *led_cdev)
  82 {
  83         u32 *pattern;
  84         unsigned int size = 0;
  85
  86         pattern = led_get_default_pattern(led_cdev, &size);
  87         if (!pattern)
  88                 return;
  89
  90         if (size != 2) {
  91                 dev_warn(led_cdev->dev,
  92                          "Expected 2 but got %u values for delays pattern\n",
  93                          size);
  94                 goto out;
  95         }
  96
  97         led_cdev->blink_delay_on = pattern[0];
  98         led_cdev->blink_delay_off = pattern[1];
  99         /* led_blink_set() called by caller */
 100
 101 out:
 102         kfree(pattern);
 103 }
 104
 105 static int timer_trig_activate(struct led_classdev *led_cdev)
 106 {
 107         if (led_cdev->flags & LED_INIT_DEFAULT_TRIGGER) {
 108                 pattern_init(led_cdev);
 109                 /*
 110                  * Mark as initialized even on pattern_init() error because
 111                  * any consecutive call to it would produce the same error.
 112                  */
 113                 led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;
 114         }
 115
 116         led_blink_set(led_cdev, &led_cdev->blink_delay_on,
 117                       &led_cdev->blink_delay_off);
 118
 119         return 0;
 120 }
 121
 122 static void timer_trig_deactivate(struct led_classdev *led_cdev)
 123 {
 124         /* Stop blinking */
 125         led_set_brightness(led_cdev, LED_OFF);
 126 }
 127
 128 static struct led_trigger timer_led_trigger = {
 129         .name     = "timer",
 130         .activate = timer_trig_activate,
 131         .deactivate = timer_trig_deactivate,
 132         .groups = timer_trig_groups,
 133 };
 134 module_led_trigger(timer_led_trigger);
 135
 136 MODULE_AUTHOR("Richard Purdie <[email protected]>");
 137 MODULE_DESCRIPTION("Timer LED trigger");
 138 MODULE_LICENSE("GPL v2");