drivers/leds/trigger/ledtrig-timer.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * LED Kernel Timer Trigger
   4  *
   5  * Copyright 2005-2006 Openedhand Ltd.
   6  *
   7  * Author: Richard Purdie <rpurdie@openedhand.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/device.h>
  14 #include <linux/ctype.h>
  15 #include <linux/slab.h>
  16 #include <linux/leds.h>
  17
  18 static ssize_t led_delay_on_show(struct device *dev,
  19                 struct device_attribute *attr, char *buf)
  20 {
  21         struct led_classdev *led_cdev = led_trigger_get_led(dev);
  22
  23         return sprintf(buf, "%lu\n", led_cdev->blink_delay_on);
  24 }
  25
  26 static ssize_t led_delay_on_store(struct device *dev,
  27                 struct device_attribute *attr, const char *buf, size_t size)
  28 {
  29         struct led_classdev *led_cdev = led_trigger_get_led(dev);
  30         unsigned long state;
  31         ssize_t ret = -EINVAL;
  32
  33         ret = kstrtoul(buf, 10, &state);
  34         if (ret)
  35                 return ret;
  36
  37         led_blink_set(led_cdev, &state, &led_cdev->blink_delay_off);
  38         led_cdev->blink_delay_on = state;
  39
  40         return size;
  41 }
  42
  43 static ssize_t led_delay_off_show(struct device *dev,
  44                 struct device_attribute *attr, char *buf)
  45 {
  46         struct led_classdev *led_cdev = led_trigger_get_led(dev);
  47
  48         return sprintf(buf, "%lu\n", led_cdev->blink_delay_off);
  49 }
  50
  51 static ssize_t led_delay_off_store(struct device *dev,
  52                 struct device_attribute *attr, const char *buf, size_t size)
  53 {
  54         struct led_classdev *led_cdev = led_trigger_get_led(dev);
  55         unsigned long state;
  56         ssize_t ret = -EINVAL;
  57
  58         ret = kstrtoul(buf, 10, &state);
  59         if (ret)
  60                 return ret;
  61
  62         led_blink_set(led_cdev, &led_cdev->blink_delay_on, &state);
  63         led_cdev->blink_delay_off = state;
  64
  65         return size;
  66 }
  67
  68 static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
  69 static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
  70
  71 static struct attribute *timer_trig_attrs[] = {
  72         &dev_attr_delay_on.attr,
  73         &dev_attr_delay_off.attr,
  74         NULL
  75 };
  76 ATTRIBUTE_GROUPS(timer_trig);
  77
  78 static void pattern_init(struct led_classdev *led_cdev)
  79 {
  80         u32 *pattern;
  81         unsigned int size = 0;
  82
  83         pattern = led_get_default_pattern(led_cdev, &size);
  84         if (!pattern)
  85                 return;
  86
  87         if (size != 2) {
  88                 dev_warn(led_cdev->dev,
  89                          "Expected 2 but got %u values for delays pattern\n",
  90                          size);
  91                 goto out;
  92         }
  93
  94         led_cdev->blink_delay_on = pattern[0];
  95         led_cdev->blink_delay_off = pattern[1];
  96         /* led_blink_set() called by caller */
  97
  98 out:
  99         kfree(pattern);
 100 }
 101
 102 static int timer_trig_activate(struct led_classdev *led_cdev)
 103 {
 104         if (led_cdev->flags & LED_INIT_DEFAULT_TRIGGER) {
 105                 pattern_init(led_cdev);
 106                 /*
 107                  * Mark as initialized even on pattern_init() error because
 108                  * any consecutive call to it would produce the same error.
 109                  */
 110                 led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;
 111         }
 112
 113         /*
 114          * If "set brightness to 0" is pending in workqueue, we don't
 115          * want that to be reordered after blink_set()
 116          */
 117         flush_work(&led_cdev->set_brightness_work);
 118         led_blink_set(led_cdev, &led_cdev->blink_delay_on,
 119                       &led_cdev->blink_delay_off);
 120
 121         return 0;
 122 }
 123
 124 static void timer_trig_deactivate(struct led_classdev *led_cdev)
 125 {
 126         /* Stop blinking */
 127         led_set_brightness(led_cdev, LED_OFF);
 128 }
 129
 130 static struct led_trigger timer_led_trigger = {
 131         .name     = "timer",
 132         .activate = timer_trig_activate,
 133         .deactivate = timer_trig_deactivate,
 134         .groups = timer_trig_groups,
 135 };
 136 module_led_trigger(timer_led_trigger);
 137
 138 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
 139 MODULE_DESCRIPTION("Timer LED trigger");
 140 MODULE_LICENSE("GPL v2");