5bb629c504
Add two new functions, led_blink_set_oneshot and led_trigger_blink_oneshot, to be used by triggers for one-shot blink of led devices. This is implemented extending the existing software-blink code, and uses the same timer and handler function. The behavior of the code is to do a blink-on, blink-off sequence when the function is called, ignoring other calls until the sequence is completed so that the leds keep blinking at constant rate if the functions are called repeatedly. This is meant to be used by drivers which needs to trigger on sporadic event, but doesn't have clear busy/idle trigger points. After the blink sequence the led remains off. This behavior can be inverted setting the "invert" argument, which blink the led off, than on and leave the led on after the sequence. (bryan.wu@canonical.com: rebase to commit 'leds: don't disable blinking when writing the same value to delay_on or delay_off') Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com> Acked-by: Shuah Khan <shuahkhan@gmail.com> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
120 lines
2.9 KiB
C
120 lines
2.9 KiB
C
/*
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* LED Class Core
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*
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* Copyright 2005-2006 Openedhand Ltd.
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*
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* Author: Richard Purdie <rpurdie@openedhand.com>
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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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#include <linux/kernel.h>
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#include <linux/list.h>
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#include <linux/module.h>
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#include <linux/rwsem.h>
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#include <linux/leds.h>
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#include "leds.h"
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DECLARE_RWSEM(leds_list_lock);
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EXPORT_SYMBOL_GPL(leds_list_lock);
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LIST_HEAD(leds_list);
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EXPORT_SYMBOL_GPL(leds_list);
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static void led_stop_software_blink(struct led_classdev *led_cdev)
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{
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/* deactivate previous settings */
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led_cdev->blink_delay_on = 0;
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led_cdev->blink_delay_off = 0;
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}
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static void led_set_software_blink(struct led_classdev *led_cdev,
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unsigned long delay_on,
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unsigned long delay_off)
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{
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int current_brightness;
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current_brightness = led_get_brightness(led_cdev);
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if (current_brightness)
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led_cdev->blink_brightness = current_brightness;
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if (!led_cdev->blink_brightness)
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led_cdev->blink_brightness = led_cdev->max_brightness;
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led_cdev->blink_delay_on = delay_on;
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led_cdev->blink_delay_off = delay_off;
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/* never on - don't blink */
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if (!delay_on)
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return;
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/* never off - just set to brightness */
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if (!delay_off) {
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led_set_brightness(led_cdev, led_cdev->blink_brightness);
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return;
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}
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mod_timer(&led_cdev->blink_timer, jiffies + 1);
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}
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void led_blink_setup(struct led_classdev *led_cdev,
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unsigned long *delay_on,
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unsigned long *delay_off)
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{
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if (!(led_cdev->flags & LED_BLINK_ONESHOT) &&
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led_cdev->blink_set &&
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!led_cdev->blink_set(led_cdev, delay_on, delay_off))
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return;
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/* blink with 1 Hz as default if nothing specified */
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if (!*delay_on && !*delay_off)
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*delay_on = *delay_off = 500;
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led_set_software_blink(led_cdev, *delay_on, *delay_off);
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}
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void led_blink_set(struct led_classdev *led_cdev,
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unsigned long *delay_on,
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unsigned long *delay_off)
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{
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del_timer_sync(&led_cdev->blink_timer);
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led_cdev->flags &= ~LED_BLINK_ONESHOT;
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led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
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led_blink_setup(led_cdev, delay_on, delay_off);
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}
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EXPORT_SYMBOL(led_blink_set);
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void led_blink_set_oneshot(struct led_classdev *led_cdev,
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unsigned long *delay_on,
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unsigned long *delay_off,
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int invert)
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{
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if ((led_cdev->flags & LED_BLINK_ONESHOT) &&
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timer_pending(&led_cdev->blink_timer))
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return;
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led_cdev->flags |= LED_BLINK_ONESHOT;
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led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
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if (invert)
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led_cdev->flags |= LED_BLINK_INVERT;
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else
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led_cdev->flags &= ~LED_BLINK_INVERT;
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led_blink_setup(led_cdev, delay_on, delay_off);
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}
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EXPORT_SYMBOL(led_blink_set_oneshot);
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void led_brightness_set(struct led_classdev *led_cdev,
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enum led_brightness brightness)
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{
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led_stop_software_blink(led_cdev);
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led_cdev->brightness_set(led_cdev, brightness);
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}
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EXPORT_SYMBOL(led_brightness_set);
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