mayhem-firmware/firmware/common/backlight.hpp

/*
 * 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.
 */

#pragma once

#include <cstdint>

namespace portapack {

class Backlight {
   public:
    using value_t = int_fast8_t;

    virtual ~Backlight() = default;

    virtual value_t levels() const = 0;

    virtual void set_level(const value_t value) = 0;
    virtual value_t level() const = 0;

    virtual void increase() = 0;
    virtual void decrease() = 0;

    virtual void on() = 0;
    virtual void off() = 0;

    virtual bool is_on() const = 0;
};

class BacklightBase : public Backlight {
   public:
    void increase() override {
        set_level(level() + 1);
    }

    void decrease() override {
        set_level(level() - 1);
    }
};

class BacklightOnOff : public BacklightBase {
   public:
    value_t levels() const override {
        return 1;
    }

    void set_level(const value_t) override {
    }

    value_t level() const override {
        return levels() - 1;
    }

    void on() override;
    void off() override;

    bool is_on() const override {
        return on_;
    }

   private:
    static constexpr value_t maximum_level = 1;

    bool on_{false};
};

class BacklightCAT4004 : public BacklightBase {
   public:
    value_t levels() const override {
        return maximum_level + 1;
    }

    void set_level(const value_t value) override;

    value_t level() const override {
        return level_;
    }

    void on() override;
    void off() override;

    bool is_on() const override {
        return on_;
    }

   private:
    static constexpr value_t initial_brightness = 25;
    static constexpr value_t maximum_level = 31;

    static constexpr uint32_t ticks_setup = 204e6 * 10e-6;
    static constexpr uint32_t ms_pwrdwn = 5;
    static constexpr uint32_t ticks_lo = 204e6 * 1e-6;
    static constexpr uint32_t ticks_hi = 204e6 * 1e-6;

    value_t level_{initial_brightness};
    bool on_{false};

    void pulses(value_t target);
    void pulse();
};

} /* namespace portapack */