mirror of https://gitee.com/openkylin/linux.git
199 lines
5.3 KiB
C
199 lines
5.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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//
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// LED Kernel Transient Trigger
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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.rst for details
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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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#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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struct led_classdev *led_cdev;
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};
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static void transient_timer_function(struct timer_list *t)
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{
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struct transient_trig_data *transient_data =
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from_timer(transient_data, t, timer);
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struct led_classdev *led_cdev = transient_data->led_cdev;
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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 transient_trig_data *transient_data =
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led_trigger_get_drvdata(dev);
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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 = led_trigger_get_led(dev);
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struct transient_trig_data *transient_data =
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led_trigger_get_drvdata(dev);
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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 transient_trig_data *transient_data = led_trigger_get_drvdata(dev);
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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 transient_trig_data *transient_data =
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led_trigger_get_drvdata(dev);
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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 transient_trig_data *transient_data =
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led_trigger_get_drvdata(dev);
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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 transient_trig_data *transient_data =
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led_trigger_get_drvdata(dev);
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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 struct attribute *transient_trig_attrs[] = {
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&dev_attr_activate.attr,
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&dev_attr_duration.attr,
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&dev_attr_state.attr,
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NULL
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};
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ATTRIBUTE_GROUPS(transient_trig);
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static int transient_trig_activate(struct led_classdev *led_cdev)
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{
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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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return -ENOMEM;
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led_set_trigger_data(led_cdev, tdata);
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tdata->led_cdev = led_cdev;
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timer_setup(&tdata->timer, transient_timer_function, 0);
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return 0;
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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_get_trigger_data(led_cdev);
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del_timer_sync(&transient_data->timer);
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led_set_brightness_nosleep(led_cdev, transient_data->restore_state);
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kfree(transient_data);
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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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.groups = transient_trig_groups,
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};
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module_led_trigger(transient_trigger);
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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 v2");
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