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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006 by Linus Nielsen Feltzing
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* 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 "system.h"
#include "backlight-target.h"
#include "avic-imx31.h"
/* Most code in here is taken from the Linux BSP provided by Freescale
* Copyright 2004-2006 Freescale Semiconductor, Inc. All Rights Reserved. */
static uint32_t int_btn = BUTTON_NONE;
static bool hold_button = false;
static bool hold_button_old = false;
#define _button_hold() (GPIO3_DR & 0x10)
static __attribute__((interrupt("IRQ"))) void KPP_HANDLER(void)
{
static const int key_mtx[5][3] =
{
{ BUTTON_LEFT, BUTTON_BACK, BUTTON_VOL_UP },
{ BUTTON_UP, BUTTON_MENU, BUTTON_VOL_DOWN },
{ BUTTON_DOWN, BUTTON_NONE, BUTTON_PREV },
{ BUTTON_RIGHT, BUTTON_NONE, BUTTON_PLAY },
{ BUTTON_SELECT, BUTTON_NONE, BUTTON_NEXT },
};
unsigned short reg_val;
int col, row;
int i;
int button = BUTTON_NONE;
/* 1. Disable both (depress and release) keypad interrupts. */
KPP_KPSR &= ~(KPP_KPSR_KRIE | KPP_KPSR_KDIE);
for (col = 0; col < 3; col++) /* Col */
{
/* 2. Write 1s to KPDR[10:8] setting column data to 1s */
KPP_KPDR |= (0x7 << 8);
/* 3. Configure columns as totem pole outputs(for quick
* discharging of keypad capacitance) */
KPP_KPCR &= ~(0x7 << 8);
/* Give the columns time to discharge */
for (i = 0; i < 256; i++)
asm volatile ("");
/* 4. Configure columns as open-drain */
KPP_KPCR |= (0x7 << 8);
/* 5. Write a single column to 0, others to 1.
* 6. Sample row inputs and save data. Multiple key presses
* can be detected on a single column.
* 7. Repeat steps 2 - 6 for remaining columns. */
/* Col bit starts at 8th bit in KPDR */
KPP_KPDR &= ~(1 << (8 + col));
/* Delay added to avoid propagating the 0 from column to row
* when scanning. */
for (i = 0; i < 256; i++)
asm volatile ("");
/* Read row input */
reg_val = KPP_KPDR;
for (row = 0; row < 5; row++) /* sample row */
{
if (!(reg_val & (1 << row)))
button |= key_mtx[row][col];
}
}
/* 8. Return all columns to 0 in preparation for standby mode. */
KPP_KPDR &= ~(0x7 << 8);
/* 9. Clear KPKD and KPKR status bit(s) by writing to a .1.,
* set the KPKR synchronizer chain by writing "1" to KRSS register,
* clear the KPKD synchronizer chain by writing "1" to KDSC register */
KPP_KPSR = KPP_KPSR_KRSS | KPP_KPSR_KDSC | KPP_KPSR_KPKR | KPP_KPSR_KPKD;
/* 10. Re-enable the appropriate keypad interrupt(s) so that the KDIE
* detects a key hold condition, or the KRIE detects a key-release
* event. */
if (button != BUTTON_NONE)
KPP_KPSR |= KPP_KPSR_KRIE;
else
KPP_KPSR |= KPP_KPSR_KDIE;
int_btn = button;
}
void button_init_device(void)
{
/* Enable keypad clock */
CLKCTL_CGR1 |= (3 << 2*10);
/* 1. Enable number of rows in keypad (KPCR[4:0])
*
* Configure the rows/cols in KPP
* LSB nybble in KPP is for 5 rows
* MSB nybble in KPP is for 3 cols */
KPP_KPCR |= 0x1f;
/* 2. Write 0's to KPDR[10:8] */
KPP_KPDR &= ~(0x7 << 8);
/* 3. Configure the keypad columns as open-drain (KPCR[10:8]). */
KPP_KPCR |= (0x7 << 8);
/* 4. Configure columns as output, rows as input (KDDR[10:8,4:0]) */
KPP_KDDR = (KPP_KDDR | (0x7 << 8)) & ~0x1f;
/* 5. Clear the KPKD Status Flag and Synchronizer chain.
* 6. Set the KDIE control bit, and set the KRIE control
* bit (to force immediate scan). */
KPP_KPSR = KPP_KPSR_KRIE | KPP_KPSR_KDIE | KPP_KPSR_KRSS |
KPP_KPSR_KDSC | KPP_KPSR_KPKR | KPP_KPSR_KPKD;
/* KPP IRQ at priority 3 */
avic_enable_int(KPP, IRQ, 3, KPP_HANDLER);
}
bool button_hold(void)
{
return _button_hold();
}
int button_read_device(void)
{
/* Simple poll of GPIO status */
hold_button = _button_hold();
/* Backlight hold handling */
if (hold_button != hold_button_old)
{
hold_button_old = hold_button;
backlight_hold_changed(hold_button);
}
/* If hold, ignore any pressed button */
return hold_button ? BUTTON_NONE : int_btn;
}
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