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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2002 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 "kernel.h"
#include "thread.h"
#include "string.h"
#include "adc.h"
#include "pcf50605.h"
struct adc_struct {
long timeout;
void (*conversion)(unsigned short *data);
short channelnum;
unsigned short data;
};
static struct adc_struct adcdata[NUM_ADC_CHANNELS] IDATA_ATTR;
static unsigned short _adc_read(struct adc_struct *adc)
{
if (adc->timeout < current_tick) {
unsigned char data[2];
unsigned short value;
/* 5x per 2 seconds */
adc->timeout = current_tick + (HZ * 2 / 5);
/* ADCC1, 10 bit, start */
pcf50605_write(0x2f, (adc->channelnum << 1) | 0x1);
pcf50605_read_multiple(0x30, data, 2); /* ADCS1, ADCS2 */
value = data[0];
value <<= 2;
value |= data[1] & 0x3;
if (adc->conversion) {
adc->conversion(&value);
}
adc->data = value;
return value;
} else {
return adc->data;
}
}
/* Force an ADC scan _now_ */
unsigned short adc_scan(int channel) {
struct adc_struct *adc = &adcdata[channel];
adc->timeout = 0;
return _adc_read(adc);
}
/* Retrieve the ADC value, only does a scan periodically */
unsigned short adc_read(int channel) {
return _adc_read(&adcdata[channel]);
}
void adc_init(void)
{
struct adc_struct *adc_battery = &adcdata[ADC_BATTERY];
adc_battery->channelnum = 0x2; /* ADCVIN1, resistive divider */
adc_battery->timeout = 0;
_adc_read(adc_battery);
}
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