leds/trigger/ledtrig-timer.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * LED Kernel Timer Trigger
0004  *
0005  * Copyright 2005-2006 Openedhand Ltd.
0006  *
0007  * Author: Richard Purdie <rpurdie@openedhand.com>
0008  */
0009
0010 #include <linux/module.h>
0011 #include <linux/kernel.h>
0012 #include <linux/init.h>
0013 #include <linux/device.h>
0014 #include <linux/ctype.h>
0015 #include <linux/slab.h>
0016 #include <linux/leds.h>
0017
0018 static ssize_t led_delay_on_show(struct device *dev,
0019         struct device_attribute *attr, char *buf)
0020 {
0021     struct led_classdev *led_cdev = led_trigger_get_led(dev);
0022
0023     return sprintf(buf, "%lu\n", led_cdev->blink_delay_on);
0024 }
0025
0026 static ssize_t led_delay_on_store(struct device *dev,
0027         struct device_attribute *attr, const char *buf, size_t size)
0028 {
0029     struct led_classdev *led_cdev = led_trigger_get_led(dev);
0030     unsigned long state;
0031     ssize_t ret;
0032
0033     ret = kstrtoul(buf, 10, &state);
0034     if (ret)
0035         return ret;
0036
0037     led_blink_set(led_cdev, &state, &led_cdev->blink_delay_off);
0038     led_cdev->blink_delay_on = state;
0039
0040     return size;
0041 }
0042
0043 static ssize_t led_delay_off_show(struct device *dev,
0044         struct device_attribute *attr, char *buf)
0045 {
0046     struct led_classdev *led_cdev = led_trigger_get_led(dev);
0047
0048     return sprintf(buf, "%lu\n", led_cdev->blink_delay_off);
0049 }
0050
0051 static ssize_t led_delay_off_store(struct device *dev,
0052         struct device_attribute *attr, const char *buf, size_t size)
0053 {
0054     struct led_classdev *led_cdev = led_trigger_get_led(dev);
0055     unsigned long state;
0056     ssize_t ret;
0057
0058     ret = kstrtoul(buf, 10, &state);
0059     if (ret)
0060         return ret;
0061
0062     led_blink_set(led_cdev, &led_cdev->blink_delay_on, &state);
0063     led_cdev->blink_delay_off = state;
0064
0065     return size;
0066 }
0067
0068 static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
0069 static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
0070
0071 static struct attribute *timer_trig_attrs[] = {
0072     &dev_attr_delay_on.attr,
0073     &dev_attr_delay_off.attr,
0074     NULL
0075 };
0076 ATTRIBUTE_GROUPS(timer_trig);
0077
0078 static void pattern_init(struct led_classdev *led_cdev)
0079 {
0080     u32 *pattern;
0081     unsigned int size = 0;
0082
0083     pattern = led_get_default_pattern(led_cdev, &size);
0084     if (!pattern)
0085         return;
0086
0087     if (size != 2) {
0088         dev_warn(led_cdev->dev,
0089              "Expected 2 but got %u values for delays pattern\n",
0090              size);
0091         goto out;
0092     }
0093
0094     led_cdev->blink_delay_on = pattern[0];
0095     led_cdev->blink_delay_off = pattern[1];
0096     /* led_blink_set() called by caller */
0097
0098 out:
0099     kfree(pattern);
0100 }
0101
0102 static int timer_trig_activate(struct led_classdev *led_cdev)
0103 {
0104     if (led_cdev->flags & LED_INIT_DEFAULT_TRIGGER) {
0105         pattern_init(led_cdev);
0106         /*
0107          * Mark as initialized even on pattern_init() error because
0108          * any consecutive call to it would produce the same error.
0109          */
0110         led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;
0111     }
0112
0113     /*
0114      * If "set brightness to 0" is pending in workqueue, we don't
0115      * want that to be reordered after blink_set()
0116      */
0117     flush_work(&led_cdev->set_brightness_work);
0118     led_blink_set(led_cdev, &led_cdev->blink_delay_on,
0119               &led_cdev->blink_delay_off);
0120
0121     return 0;
0122 }
0123
0124 static void timer_trig_deactivate(struct led_classdev *led_cdev)
0125 {
0126     /* Stop blinking */
0127     led_set_brightness(led_cdev, LED_OFF);
0128 }
0129
0130 static struct led_trigger timer_led_trigger = {
0131     .name     = "timer",
0132     .activate = timer_trig_activate,
0133     .deactivate = timer_trig_deactivate,
0134     .groups = timer_trig_groups,
0135 };
0136 module_led_trigger(timer_led_trigger);
0137
0138 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
0139 MODULE_DESCRIPTION("Timer LED trigger");
0140 MODULE_LICENSE("GPL v2");