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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2009 by Bertrik Sikken
*
* 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 "inttypes.h"
#include "s5l87xx.h"
#include "adc.h"
#include "adc-target.h"
#include "kernel.h"
/* Driver for the built-in ADC of the s5l8700
The ADC is put into standby mode after each conversion.
*/
#define ADC_PRESCALER 100 /* 1MHz ADC clock, assuming 100 MHz PCLK */
#define ADC_DEFAULT (1<<14) | /* prescale enable */ \
((ADC_PRESCALER-1)<<6) | /* prescaler */ \
(0<<3) | /* sel_mux */ \
(0<<2) | /* stdbm */ \
(0<<1) | /* read_start */ \
(0<<0) /* enable start */ \
static struct mutex adc_mtx;
static struct semaphore adc_wakeup;
void INT_ADC(void)
{
semaphore_release(&adc_wakeup);
}
unsigned short adc_read(int channel)
{
unsigned short data;
mutex_lock(&adc_mtx);
/* set channel and start conversion */
ADCCON = ADC_DEFAULT |
(channel << 3) |
(1 << 0); /* enable start */
/* wait for conversion */
semaphore_wait(&adc_wakeup, TIMEOUT_BLOCK);
/* get the converted data */
data = ADCDAT0 & 0x3FF;
/* put ADC back into standby */
ADCCON |= (1 << 2);
mutex_unlock(&adc_mtx);
return data;
}
void adc_init(void)
{
mutex_init(&adc_mtx);
semaphore_init(&adc_wakeup, 1, 0);
/* enable clock to ADC */
PWRCON &= ~(1 << 10);
/* configure ADC and put in standby */
ADCCON = ADC_DEFAULT | (1 << 2);
/* configure conversion delay (use default) */
ADCDLY = 0xFF;
/* enable interrupt */
INTMSK |= (1 << 31);
}
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