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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___void
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2008 by Rob Purchase
*
* 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 "touchscreen-target.h"
#include "adc-target.h"
#include "system.h"
#include "stdlib.h"
#include "button.h"
#include "touchscreen.h"
#define NO_OF_TOUCH_DATA 5
struct touch_calibration_point {
short px_x; /* known pixel value */
short px_y;
short val_x; /* touchscreen value at the known pixel */
short val_y;
};
static struct touch_calibration_point topleft, bottomright;
static bool touch_available = false;
static short x[NO_OF_TOUCH_DATA], y[NO_OF_TOUCH_DATA];
/* comparator for qsort */
static int short_cmp(const void *a, const void *b)
{
return *(short*)a - *(short*)b;
}
static int touch_to_pixels(short val_x, short val_y)
{
short x,y;
x=val_x;
y=val_y;
x = (x-topleft.val_x)*(bottomright.px_x - topleft.px_x)
/ (bottomright.val_x - topleft.val_x) + topleft.px_x;
y = (y-topleft.val_y)*(bottomright.px_y - topleft.px_y)
/ (bottomright.val_y - topleft.val_y) + topleft.px_y;
if (x < 0)
x = 0;
else if (x>=LCD_WIDTH)
x=LCD_WIDTH-1;
if (y < 0)
y = 0;
else if (y>=LCD_HEIGHT)
y=LCD_HEIGHT-1;
return (x<<16)|y;
}
void touchscreen_init_device()
{
/* set touchscreen adc controller into wait for interrupt mode */
ADCTSC = 0xd3; /* Wfait,XP-PU,XP_DIS,XM_DIS,YP_dis,YM_end */
/* Arbitrary touchscreen calibration */
topleft.px_x = 0;
topleft.px_y = 0;
topleft.val_x = 105;
topleft.val_y = 925;
bottomright.px_x = LCD_WIDTH;
bottomright.px_y = LCD_HEIGHT;
bottomright.val_x = 890;
bottomright.val_y = 105;
touch_available = false;
}
void touchscreen_scan_device()
{
static long last_touch_read = 0;
static int touch_data_index = 0;
int saveADCDLY;
/* check touch state */
if(ADCDAT1 & (1<<15))
{
return;
}
if (TIME_AFTER(current_tick, last_touch_read + 1))
{
/* resets the index if the last touch could not be read 5 times */
touch_data_index = 0;
}
/* read touch data */
saveADCDLY = ADCDLY;
ADCDLY = 40000; /*delay ~0.8ms (1/50M)*4000 */
ADCTSC = (1<<3)|(1<<2); /* pullup disable, seq x,y pos measure */
/* start adc */
ADCCON|= 0x1;
/* wait for start and end */
while(ADCCON & 0x1);
while(!(ADCCON & 0x8000));
x[touch_data_index] = ADCDAT0&0x3ff;
y[touch_data_index] = ADCDAT1&0x3ff;
ADCTSC = 0xd3; /* back to interrupt mode */
ADCDLY = saveADCDLY;
touch_data_index++;
if (touch_data_index > NO_OF_TOUCH_DATA - 1)
{
/* coordinates 5 times read */
touch_available = true;
touch_data_index = 0;
}
last_touch_read = current_tick;
}
int touchscreen_read_device(int *data, int *old_data)
{
int btn = BUTTON_NONE;
static bool touch_hold = false;
static long last_touch = 0;
if (touch_available || touch_hold)
{
short x_touch, y_touch;
static short last_x = 0, last_y = 0;
if (touch_hold)
{
/* get rid of very fast unintended double touches */
x_touch = last_x;
y_touch = last_y;
}
else
{
/* sort the 5 data taken and use the median value */
qsort(x, NO_OF_TOUCH_DATA, sizeof(short), short_cmp);
qsort(y, NO_OF_TOUCH_DATA, sizeof(short), short_cmp);
x_touch = last_x = x[(NO_OF_TOUCH_DATA - 1)/2];
y_touch = last_y = y[(NO_OF_TOUCH_DATA - 1)/2];
last_touch = current_tick;
touch_hold = true;
touch_available = false;
}
*old_data = *data = touch_to_pixels(x_touch, y_touch);
btn |= touchscreen_to_pixels((*data&0xffff0000) >> 16,
(*data&0x0000ffff),
data);
}
if (TIME_AFTER(current_tick, last_touch + 10))
{
/* put the touchscreen back into interrupt mode */
touch_hold = false;
}
return btn;
}
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