0da3e65ba8
Rename leds internal interface led_set_brightness() to __led_set_brightness() to reduce confusion between led_set_brightness() and the external interface led_brightness_set(). led_brightness_set() cancels the timer and then calls led_set_brightness(). Signed-off-by: Shuah Khan <shuahkhan@gmail.com> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
237 lines
6.4 KiB
C
237 lines
6.4 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(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(led_cdev, 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(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 + 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(led_cdev, 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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