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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2009 Bertrik Sikken
*
* 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 <stdbool.h>
#include "config.h"
#include "inttypes.h"
#include "s5l87xx.h"
#include "button.h"
#include "button-target.h"
/* Button driver for the touch keys on the Samsung YP-S3
The exact controller is not known, but it is likely from Melfas.
The protocol is as follows:
* the communication is done using three signals: DRDY, DCLK and DOUT
* in the idle state these signals are all high.
* when a key is touched or released, the key controller pulls down DRDY
and outputs the first bit of a 20-bit word on its DOUT signal.
* the CPU stores the bit, then acknowledges it by toggling the DCLK signal.
* the key controller prepares the next bit, then toggles its DRDY output,
unless all 20 bits have been transferred (in that case it stays high).
* the 20-bit word contains separate bits for each button, some fixed bits
and a bit indicating the number of keys pressed (modulo 2).
*/
void button_init_device(void)
{
/* P0.5/P1.0 power switch input */
PCON0 &= ~(3 << 10);
PCON1 &= ~0x0000000F;
/* P1.3 headphones detect input */
PCON1 &= ~0x0000F000;
/* P1.5 DATA, P1.6 DRDY inputs (touch key controller) */
PCON1 &= ~0x0FF00000;
/* P3.4 DCLK output (touch key controller) */
PCON3 = (PCON3 & ~0x000F0000) | 0x00010000;
PDAT3 |= (1 << 4);
/* P4.3 hold switch input */
PCON4 &= ~0x0000F000;
}
/* returns the raw 20-bit word from the touch key controller */
static int tkey_read(void)
{
static int value = 0;
int i;
/* check activity */
if (PDAT1 & (1 << 6)) {
return value;
}
/* get key bits */
value = 0;
for (i = 0; i < 10; i++) {
/* sample bit from falling edge of DRDY */
while ((PDAT1 & (1 << 6)) != 0);
value <<= 1;
if (PDAT1 & (1 << 5)) {
value |= 1;
}
/* acknowledge on DCLK */
PDAT3 &= ~(1 << 4);
/* sample bit from rising edge of DRDY */
while ((PDAT1 & (1 << 6)) == 0);
value <<= 1;
if (PDAT1 & (1 << 5)) {
value |= 1;
}
/* acknowledge on DCLK */
PDAT3 |= (1 << 4);
}
return value;
}
int button_read_device(void)
{
int buttons = 0;
int tkey_data;
/* hold switch */
if (button_hold()) {
return 0;
}
/* power button */
if (PDAT1 & (1 << 0)) {
buttons |= BUTTON_POWER;
}
/* touch keys */
tkey_data = tkey_read();
if (tkey_data & (1 << 9)) {
buttons |= BUTTON_BACK;
}
if (tkey_data & (1 << 8)) {
buttons |= BUTTON_UP;
}
if (tkey_data & (1 << 7)) {
buttons |= BUTTON_MENU;
}
if (tkey_data & (1 << 6)) {
buttons |= BUTTON_LEFT;
}
if (tkey_data & (1 << 5)) {
buttons |= BUTTON_SELECT;
}
if (tkey_data & (1 << 4)) {
buttons |= BUTTON_RIGHT;
}
if (tkey_data & (1 << 3)) {
buttons |= BUTTON_DOWN;
}
return buttons;
}
bool button_hold(void)
{
return (PDAT4 & (1 << 3));
}
bool headphones_inserted(void)
{
return ((PDAT1 & (1 << 3)) == 0);
}
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