2acc0ac542
later. We still need to hunt down snippets used that are not. 1324 modified files... http://www.rockbox.org/mail/archive/rockbox-dev-archive-2008-06/0060.shtml git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17847 a1c6a512-1295-4272-9138-f99709370657
115 lines
2.9 KiB
C
115 lines
2.9 KiB
C
/***************************************************************************
|
|
* __________ __ ___.
|
|
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
|
|
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
|
|
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
|
|
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
|
|
* \/ \/ \/ \/ \/
|
|
* $Id$
|
|
*
|
|
* Copyright (C) 2006 by Linus Nielsen Feltzing
|
|
*
|
|
* 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 "kernel.h"
|
|
#include "thread.h"
|
|
#include "adc.h"
|
|
|
|
|
|
#define CS_LO and_l(~0x80, &GPIO_OUT)
|
|
#define CS_HI or_l(0x80, &GPIO_OUT)
|
|
#define CLK_LO and_l(~0x00400000, &GPIO_OUT)
|
|
#define CLK_HI or_l(0x00400000, &GPIO_OUT)
|
|
#define DO (GPIO_READ & 0x80000000)
|
|
#define DI_LO and_l(~0x00200000, &GPIO_OUT)
|
|
#define DI_HI or_l(0x00200000, &GPIO_OUT)
|
|
|
|
/* delay loop */
|
|
#define DELAY \
|
|
({ \
|
|
int _x_; \
|
|
asm volatile ( \
|
|
"move.l #11, %[_x_] \r\n" \
|
|
"1: \r\n" \
|
|
"subq.l #1, %[_x_] \r\n" \
|
|
"bhi.b 1b \r\n" \
|
|
: [_x_]"=&d"(_x_) \
|
|
); \
|
|
})
|
|
|
|
unsigned short adc_scan(int channel)
|
|
{
|
|
int level = disable_irq_save();
|
|
unsigned char data = 0;
|
|
int i;
|
|
|
|
CS_LO;
|
|
|
|
DI_HI; /* Start bit */
|
|
DELAY;
|
|
CLK_HI;
|
|
DELAY;
|
|
CLK_LO;
|
|
|
|
DI_HI; /* Single channel */
|
|
DELAY;
|
|
CLK_HI;
|
|
DELAY;
|
|
CLK_LO;
|
|
|
|
if(channel & 1) /* LSB of channel number */
|
|
DI_HI;
|
|
else
|
|
DI_LO;
|
|
DELAY;
|
|
CLK_HI;
|
|
DELAY;
|
|
CLK_LO;
|
|
|
|
if(channel & 2) /* MSB of channel number */
|
|
DI_HI;
|
|
else
|
|
DI_LO;
|
|
DELAY;
|
|
CLK_HI;
|
|
DELAY;
|
|
CLK_LO;
|
|
|
|
DELAY;
|
|
|
|
for(i = 0;i < 8;i++) /* 8 bits of data */
|
|
{
|
|
CLK_HI;
|
|
DELAY;
|
|
CLK_LO;
|
|
DELAY;
|
|
data <<= 1;
|
|
data |= DO?1:0;
|
|
}
|
|
|
|
CS_HI;
|
|
|
|
restore_irq(level);
|
|
return data;
|
|
}
|
|
|
|
void adc_init(void)
|
|
{
|
|
or_l(0x80600080, &GPIO_FUNCTION); /* GPIO7: CS
|
|
GPIO21: Data In (to the ADC)
|
|
GPIO22: CLK
|
|
GPIO31: Data Out (from the ADC) */
|
|
or_l(0x00600080, &GPIO_ENABLE);
|
|
or_l(0x80, &GPIO_OUT); /* CS high */
|
|
and_l(~0x00400000, &GPIO_OUT); /* CLK low */
|
|
}
|