rockbox/firmware/target/hosted/backlight-unix.c

/***************************************************************************
 *             __________               __   ___
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 *
 * Copyright (C) 2017 Marcin Bukat
 * Copyright (C) 2019 by Roman Stolyarov
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdbool.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include "config.h"
#include "backlight-target.h"
#include "sysfs.h"
#include "panic.h"
#include "lcd.h"

static const char * const sysfs_bl_brightness =
    "/sys/class/backlight/pwm-backlight.0/brightness";

static const char * const sysfs_bl_power =
    "/sys/class/backlight/pwm-backlight.0/bl_power";

bool backlight_hw_init(void)
{
    backlight_hw_on();
    backlight_hw_brightness(DEFAULT_BRIGHTNESS_SETTING);
    return true;
}

static int last_bl = -1;

void backlight_hw_on(void)
{
    if (last_bl != 1) {
#ifdef HAVE_LCD_ENABLE
        lcd_enable(true);
#endif
        sysfs_set_int(sysfs_bl_power, 0);
	last_bl = 1;
    }
}

void backlight_hw_off(void)
{
    if (last_bl != 0) {
        sysfs_set_int(sysfs_bl_power, 1);
#ifdef HAVE_LCD_ENABLE
        lcd_enable(false);
#endif
	last_bl = 0;
    }
}

void backlight_hw_brightness(int brightness)
{
    /* cap range, just in case */
    if (brightness > MAX_BRIGHTNESS_SETTING)
        brightness = MAX_BRIGHTNESS_SETTING;
    if (brightness < MIN_BRIGHTNESS_SETTING)
        brightness = MIN_BRIGHTNESS_SETTING;

    sysfs_set_int(sysfs_bl_brightness, brightness);
}