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![Rob Herring](/assets/img/avatar_default.png)
The transient trigger duration is documented to be in msec units, but is actually in jiffies units. Other time based triggers are in msec units as well. Fix the timer setup to convert from msec. This could break an existing userspace that worked around this problem, but exposing jiffies to userspace is just wrong and would break anyway if HZ is changed. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Shuah Khan <shuahkhan@gmail.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: linux-leds@vger.kernel.org Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
239 lines
6.5 KiB
C
239 lines
6.5 KiB
C
/*
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* LED Kernel Transient Trigger
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*
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* Copyright (C) 2012 Shuah Khan <shuahkhan@gmail.com>
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*
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* Based on Richard Purdie's ledtrig-timer.c and Atsushi Nemoto's
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* ledtrig-heartbeat.c
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* Design and use-case input from Jonas Bonn <jonas@southpole.se> and
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* Neil Brown <neilb@suse.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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/*
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* Transient trigger allows one shot timer activation. Please refer to
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* Documentation/leds/ledtrig-transient.txt for details
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/slab.h>
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#include <linux/timer.h>
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#include <linux/leds.h>
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#include "../leds.h"
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struct transient_trig_data {
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int activate;
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int state;
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int restore_state;
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unsigned long duration;
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struct timer_list timer;
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};
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static void transient_timer_function(unsigned long data)
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{
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struct led_classdev *led_cdev = (struct led_classdev *) data;
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struct transient_trig_data *transient_data = led_cdev->trigger_data;
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transient_data->activate = 0;
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led_set_brightness_nosleep(led_cdev, transient_data->restore_state);
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}
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static ssize_t transient_activate_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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struct transient_trig_data *transient_data = led_cdev->trigger_data;
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return sprintf(buf, "%d\n", transient_data->activate);
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}
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static ssize_t transient_activate_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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struct transient_trig_data *transient_data = led_cdev->trigger_data;
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unsigned long state;
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ssize_t ret;
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ret = kstrtoul(buf, 10, &state);
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if (ret)
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return ret;
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if (state != 1 && state != 0)
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return -EINVAL;
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/* cancel the running timer */
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if (state == 0 && transient_data->activate == 1) {
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del_timer(&transient_data->timer);
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transient_data->activate = state;
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led_set_brightness_nosleep(led_cdev,
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transient_data->restore_state);
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return size;
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}
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/* start timer if there is no active timer */
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if (state == 1 && transient_data->activate == 0 &&
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transient_data->duration != 0) {
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transient_data->activate = state;
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led_set_brightness_nosleep(led_cdev, transient_data->state);
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transient_data->restore_state =
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(transient_data->state == LED_FULL) ? LED_OFF : LED_FULL;
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mod_timer(&transient_data->timer,
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jiffies + msecs_to_jiffies(transient_data->duration));
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}
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/* state == 0 && transient_data->activate == 0
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timer is not active - just return */
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/* state == 1 && transient_data->activate == 1
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timer is already active - just return */
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return size;
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}
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static ssize_t transient_duration_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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struct transient_trig_data *transient_data = led_cdev->trigger_data;
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return sprintf(buf, "%lu\n", transient_data->duration);
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}
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static ssize_t transient_duration_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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struct transient_trig_data *transient_data = led_cdev->trigger_data;
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unsigned long state;
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ssize_t ret;
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ret = kstrtoul(buf, 10, &state);
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if (ret)
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return ret;
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transient_data->duration = state;
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return size;
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}
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static ssize_t transient_state_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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struct transient_trig_data *transient_data = led_cdev->trigger_data;
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int state;
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state = (transient_data->state == LED_FULL) ? 1 : 0;
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return sprintf(buf, "%d\n", state);
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}
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static ssize_t transient_state_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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struct transient_trig_data *transient_data = led_cdev->trigger_data;
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unsigned long state;
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ssize_t ret;
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ret = kstrtoul(buf, 10, &state);
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if (ret)
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return ret;
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if (state != 1 && state != 0)
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return -EINVAL;
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transient_data->state = (state == 1) ? LED_FULL : LED_OFF;
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return size;
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}
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static DEVICE_ATTR(activate, 0644, transient_activate_show,
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transient_activate_store);
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static DEVICE_ATTR(duration, 0644, transient_duration_show,
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transient_duration_store);
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static DEVICE_ATTR(state, 0644, transient_state_show, transient_state_store);
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static void transient_trig_activate(struct led_classdev *led_cdev)
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{
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int rc;
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struct transient_trig_data *tdata;
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tdata = kzalloc(sizeof(struct transient_trig_data), GFP_KERNEL);
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if (!tdata) {
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dev_err(led_cdev->dev,
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"unable to allocate transient trigger\n");
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return;
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}
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led_cdev->trigger_data = tdata;
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rc = device_create_file(led_cdev->dev, &dev_attr_activate);
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if (rc)
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goto err_out;
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rc = device_create_file(led_cdev->dev, &dev_attr_duration);
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if (rc)
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goto err_out_duration;
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rc = device_create_file(led_cdev->dev, &dev_attr_state);
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if (rc)
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goto err_out_state;
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setup_timer(&tdata->timer, transient_timer_function,
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(unsigned long) led_cdev);
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led_cdev->activated = true;
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return;
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err_out_state:
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device_remove_file(led_cdev->dev, &dev_attr_duration);
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err_out_duration:
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device_remove_file(led_cdev->dev, &dev_attr_activate);
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err_out:
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dev_err(led_cdev->dev, "unable to register transient trigger\n");
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led_cdev->trigger_data = NULL;
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kfree(tdata);
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}
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static void transient_trig_deactivate(struct led_classdev *led_cdev)
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{
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struct transient_trig_data *transient_data = led_cdev->trigger_data;
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if (led_cdev->activated) {
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del_timer_sync(&transient_data->timer);
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led_set_brightness_nosleep(led_cdev,
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transient_data->restore_state);
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device_remove_file(led_cdev->dev, &dev_attr_activate);
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device_remove_file(led_cdev->dev, &dev_attr_duration);
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device_remove_file(led_cdev->dev, &dev_attr_state);
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led_cdev->trigger_data = NULL;
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led_cdev->activated = false;
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kfree(transient_data);
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}
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}
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static struct led_trigger transient_trigger = {
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.name = "transient",
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.activate = transient_trig_activate,
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.deactivate = transient_trig_deactivate,
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};
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static int __init transient_trig_init(void)
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{
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return led_trigger_register(&transient_trigger);
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}
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static void __exit transient_trig_exit(void)
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{
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led_trigger_unregister(&transient_trigger);
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}
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module_init(transient_trig_init);
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module_exit(transient_trig_exit);
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MODULE_AUTHOR("Shuah Khan <shuahkhan@gmail.com>");
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MODULE_DESCRIPTION("Transient LED trigger");
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MODULE_LICENSE("GPL");
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