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                 if (timer_data->delay_on != state) {
  81                         /* the new value differs from the previous */
  82                         timer_data->delay_on = state;
  83
  84                         /* deactivate previous settings */
  85                         del_timer_sync(&timer_data->timer);
  86
  87                         /* try to activate hardware acceleration, if any */
  88                         if (!led_cdev->blink_set ||
  89                             led_cdev->blink_set(led_cdev,
  90                                 &timer_data->delay_on, &timer_data->delay_off)) {
  91                                 /* no hardware acceleration, blink via timer */
  92                                 mod_timer(&timer_data->timer, jiffies + 1);
  93                         }
  94                 }
  95                 ret = count;
  96         }
  97
  98         return ret;
  99 }
 100
 101 static ssize_t led_delay_off_show(struct device *dev,
 102                 struct device_attribute *attr, char *buf)
 103 {
 104         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 105         struct timer_trig_data *timer_data = led_cdev->trigger_data;
 106
 107         sprintf(buf, "%lu\n", timer_data->delay_off);
 108
 109         return strlen(buf) + 1;
 110 }
 111
 112 static ssize_t led_delay_off_store(struct device *dev,
 113                 struct device_attribute *attr, const char *buf, size_t size)
 114 {
 115         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 116         struct timer_trig_data *timer_data = led_cdev->trigger_data;
 117         int ret = -EINVAL;
 118         char *after;
 119         unsigned long state = simple_strtoul(buf, &after, 10);
 120         size_t count = after - buf;
 121
 122         if (*after && isspace(*after))
 123                 count++;
 124
 125         if (count == size) {
 126                 if (timer_data->delay_off != state) {
 127                         /* the new value differs from the previous */
 128                         timer_data->delay_off = state;
 129
 130                         /* deactivate previous settings */
 131                         del_timer_sync(&timer_data->timer);
 132
 133                         /* try to activate hardware acceleration, if any */
 134                         if (!led_cdev->blink_set ||
 135                             led_cdev->blink_set(led_cdev,
 136                                 &timer_data->delay_on, &timer_data->delay_off)) {
 137                                 /* no hardware acceleration, blink via timer */
 138                                 mod_timer(&timer_data->timer, jiffies + 1);
 139                         }
 140                 }
 141                 ret = count;
 142         }
 143
 144         return ret;
 145 }
 146
 147 static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
 148 static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
 149
 150 static void timer_trig_activate(struct led_classdev *led_cdev)
 151 {
 152         struct timer_trig_data *timer_data;
 153         int rc;
 154
 155         timer_data = kzalloc(sizeof(struct timer_trig_data), GFP_KERNEL);
 156         if (!timer_data)
 157                 return;
 158
 159         led_cdev->trigger_data = timer_data;
 160
 161         init_timer(&timer_data->timer);
 162         timer_data->timer.function = led_timer_function;
 163         timer_data->timer.data = (unsigned long) led_cdev;
 164
 165         rc = device_create_file(led_cdev->dev, &dev_attr_delay_on);
 166         if (rc)
 167                 goto err_out;
 168         rc = device_create_file(led_cdev->dev, &dev_attr_delay_off);
 169         if (rc)
 170                 goto err_out_delayon;
 171
 172         /* If there is hardware support for blinking, start one
 173          * user friendly blink rate chosen by the driver.
 174          */
 175         if (led_cdev->blink_set)
 176                 led_cdev->blink_set(led_cdev,
 177                         &timer_data->delay_on, &timer_data->delay_off);
 178
 179         return;
 180
 181 err_out_delayon:
 182         device_remove_file(led_cdev->dev, &dev_attr_delay_on);
 183 err_out:
 184         led_cdev->trigger_data = NULL;
 185         kfree(timer_data);
 186 }
 187
 188 static void timer_trig_deactivate(struct led_classdev *led_cdev)
 189 {
 190         struct timer_trig_data *timer_data = led_cdev->trigger_data;
 191
 192         if (timer_data) {
 193                 device_remove_file(led_cdev->dev, &dev_attr_delay_on);
 194                 device_remove_file(led_cdev->dev, &dev_attr_delay_off);
 195                 del_timer_sync(&timer_data->timer);
 196                 kfree(timer_data);
 197         }
 198 }
 199
 200 static struct led_trigger timer_led_trigger = {
 201         .name     = "timer",
 202         .activate = timer_trig_activate,
 203         .deactivate = timer_trig_deactivate,
 204 };
 205
 206 static int __init timer_trig_init(void)
 207 {
 208         return led_trigger_register(&timer_led_trigger);
 209 }
 210
 211 static void __exit timer_trig_exit(void)
 212 {
 213         led_trigger_unregister(&timer_led_trigger);
 214 }
 215
 216 module_init(timer_trig_init);
 217 module_exit(timer_trig_exit);
 218
 219 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
 220 MODULE_DESCRIPTION("Timer LED trigger");
 221 MODULE_LICENSE("GPL");