portapack-mayhem/firmware/common/backlight.cpp

/*
 * Copyright (C) 2017 Jared Boone, ShareBrained Technology, Inc.
 *
 * This file is part of PortaPack.
 *
 * 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, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#include "backlight.hpp"

#include "portapack_io.hpp"

namespace portapack {

void BacklightOnOff::on() {
    if (!is_on()) {
        io.lcd_backlight(true);
        on_ = true;
    }
}

void BacklightOnOff::off() {
    if (is_on()) {
        io.lcd_backlight(false);
        on_ = false;
    }
}

void BacklightCAT4004::set_level(const value_t value) {
    auto target = value;

    // Clip target value to valid range.
    if (target < 0) {
        target = 0;
    }
    if (target > maximum_level) {
        target = maximum_level;
    }

    if (is_on()) {
        pulses(target);
    } else {
        level_ = target;
    }
}

void BacklightCAT4004::on() {
    if (!is_on()) {
        io.lcd_backlight(true);
        halPolledDelay(ticks_setup);
        on_ = true;

        // Just enabled driver, initial value is maximum.
        const auto target_level = level();
        level_ = maximum_level;

        pulses(target_level);
    }
}

void BacklightCAT4004::off() {
    if (is_on()) {
        io.lcd_backlight(false);
        chThdSleepMilliseconds(ms_pwrdwn);
        on_ = false;
    }
}

void BacklightCAT4004::pulses(value_t target) {
    while (level() != target) {
        pulse();
    }
}

void BacklightCAT4004::pulse() {
    io.lcd_backlight(false);
    halPolledDelay(ticks_lo);
    io.lcd_backlight(true);
    halPolledDelay(ticks_hi);

    level_ -= 1;
    if (level_ < 0) {
        level_ = levels() - 1;
    }
}

} /* namespace portapack */