/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id:$
 *
 * Copyright (C) 2010 Marcin Bukat
 *
 * 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 "config.h"
#include "cpu.h"
#include "system.h"
#include "button.h"
#include "backlight.h"
#include "adc.h"

void button_init_device(void)
{
    /* Set GPIO36, GPIO56 as general purpose inputs */
    or_l((1<<4)|(1<<24),&GPIO1_FUNCTION);
    and_l(~((1<<4)|(1<<24)),&GPIO1_ENABLE);
}

bool button_hold(void)
{
    /* GPIO36 active high */
    return (GPIO1_READ & (1<<4))?true:false;
}


/*
 * Get button pressed from hardware
 */
int button_read_device(void)
{
    int btn = BUTTON_NONE;
    int data = 0;
    static bool hold_button = false;

    /* for moving average filter */
    static unsigned short button_filter[4];
    static unsigned char index;

    bool hold_button_old;

    /* normal buttons */
    hold_button_old = hold_button;
    hold_button = button_hold();
    
    
#ifndef BOOTLOADER
    if (hold_button != hold_button_old)
        backlight_hold_changed(hold_button);
#endif

    if (!hold_button)
    {

        /* simple moving average filter with 4 item window */
        button_filter[index&0x03] = adc_scan(ADC_BUTTONS);
        index++;
        
        data = (button_filter[0]+button_filter[1] \
               +button_filter[2]+button_filter[3])>>2;


        if (data < 2250) // valid button
        {
	    if (data < 900) /* middle */
            {
                if (data < 500)
                {
                    if (data > 200)
                        /* 200 - 500 */
                        btn = BUTTON_REC;
                }
                else /* 900 - 500 */
                    btn = BUTTON_VOL_DOWN;
            }
            else /* 2250 - 900 */
            {
                if (data < 1600)
                {
                    /* 1600 - 900 */
                    if (data < 1200)
                        /* 1200 - 900 */
                        btn = BUTTON_VOL_UP;
                    else /* 1600 - 1200 */
                        btn = BUTTON_NEXT;
                }
                else /* 1600 - 2250 */
                {
                    if (data < 1900)
                        /* 1900 - 1600 */
                        btn = BUTTON_PREV;
                    else /* 1900 - 2250 */
                        btn = BUTTON_SELECT;
                }
	    }	    
        }
    }


    data = GPIO1_READ;

    /* GPIO56 active high main PLAY/PAUSE/ON */
    if (!hold_button && ((data & (1<<24))))
        btn |= BUTTON_PLAY;
        
    return btn;
}