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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006 by Barry Wardell
*
* 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 "kernel.h"
#include "thread.h"
#include "adc.h"
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;
/* Initialise */
ADC_ADDR=0x130;
ADC_STATUS=0; /* 4 bytes, 1 per channel. Each byte is 0 if the channel is
off, 0x40 if the channel is on */
/* Enable Channel */
ADC_ADDR |= (0x1000000<<channel);
/* Start? */
ADC_ADDR |= 0x20000000;
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);
/* FIXME: Hardcode a value for ~82% charge in here until we figure out the
ADC. This will avoid the low battery warning message. */
adcdata[ADC_UNREG_POWER] = 0x2C0;
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(ADC_0);
adc_scan(ADC_1);
adc_scan(ADC_2);
adc_scan(ADC_3);
}
}
void adc_init(void)
{
/* Enable ADC */
ADC_ENABLE_ADDR |= ADC_ENABLE;
/* Initialise */
ADC_INIT=0;
/* Force a scan of all channels to get initial values */
adc_scan(ADC_0);
adc_scan(ADC_1);
adc_scan(ADC_2);
adc_scan(ADC_3);
tick_add_task(adc_tick);
}
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