rockbox/firmware/target/arm/adc-pp5020.c
2009-01-27 03:19:57 +00:00

153 lines
4 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006 by Barry Wardell
*
* 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 ADC_ADDR (*(volatile unsigned long*)(0x7000ad00))
#define ADC_STATUS (*(volatile unsigned long*)(0x7000ad04))
#define ADC_DATA_1 (*(volatile unsigned long*)(0x7000ad20))
#define ADC_DATA_2 (*(volatile unsigned long*)(0x7000ad24))
#define ADC_INIT (*(volatile unsigned long*)(0x7000ad2c))
static unsigned short adcdata[NUM_ADC_CHANNELS];
/* Scan ADC so that adcdata[channel] gets updated. */
unsigned short adc_scan(int channel)
{
unsigned int adc_data_1;
unsigned int adc_data_2;
/* Start conversion */
ADC_ADDR |= 0x80000000;
/* Wait for conversion to complete */
while((ADC_STATUS & (0x40<<8*channel))==0);
/* Stop conversion */
ADC_ADDR &=~ 0x80000000;
/* ADC_DATA_1 and ADC_DATA_2 are both four bytes, one byte per channel.
For each channel, ADC_DATA_1 stores the 8-bit msb, ADC_DATA_2 stores the
2-bit lsb (in bits 0 and 1). Each channel is 10 bits total. */
adc_data_1 = ((ADC_DATA_1 >> (8*channel)) & 0xff);
adc_data_2 = ((ADC_DATA_2 >> (8*channel+6)) & 0x3);
adcdata[channel] = (adc_data_1<<2 | adc_data_2);
/* ADC values read low if PLL is enabled */
if(PLL_CONTROL & 0x80000000){
adcdata[channel] += 0x14;
if(adcdata[channel] > 0x400)
adcdata[channel] = 0x400;
}
return adcdata[channel];
}
/* Read 10-bit channel data */
unsigned short adc_read(int channel)
{
return adcdata[channel];
}
static int adc_counter;
static void adc_tick(void)
{
if(++adc_counter == HZ)
{
adc_counter = 0;
adc_scan(0);
adc_scan(1);
adc_scan(2);
adc_scan(3);
}
}
/* Figured out from how the OF does things */
void adc_init(void)
{
ADC_INIT |= 1;
ADC_INIT |= 0x40000000;
udelay(100);
/* Reset ADC */
DEV_RS2 |= 0x20;
udelay(100);
DEV_RS2 &=~ 0x20;
udelay(100);
/* Enable ADC */
DEV_EN2 |= 0x20;
udelay(100);
ADC_CLOCK_SRC |= 0x3;
udelay(100);
ADC_ADDR |= 0x40;
ADC_ADDR |= 0x20000000;
udelay(100);
ADC_INIT;
ADC_INIT = 0;
udelay(100);
ADC_STATUS = 0;
/* Enable channel 0 (battery) */
DEV_INIT1 &=~0x3;
ADC_ADDR |= 0x1000000;
ADC_STATUS |= 0x20;
/* Enable channel 1 (unknown) */
DEV_INIT1 &=~30;
ADC_ADDR |= 0x2000000;
ADC_STATUS |= 0x2000;
#if defined (IRIVER_H10) || defined(IRIVER_H10_5GB) || \
defined(MROBE_100) || defined(PHILIPS_HDD1630)
/* Enable channel 2 (H10:remote) */
DEV_INIT1 &=~0x300;
DEV_INIT1 |= 0x100;
ADC_ADDR |= 0x4000000;
ADC_STATUS |= 0x200000;
/* Enable channel 3 (H10:scroll pad) */
DEV_INIT1 &=~0x3000;
DEV_INIT1 |= 0x1000;
ADC_ADDR |= 0x8000000;
ADC_STATUS |= 0x20000000;
#endif
/* Force a scan of all channels to get initial values */
adc_scan(0);
adc_scan(1);
adc_scan(2);
adc_scan(3);
tick_add_task(adc_tick);
}