12375d1d3a
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29492 a1c6a512-1295-4272-9138-f99709370657
94 lines
2.7 KiB
C
94 lines
2.7 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2009 by Bertrik Sikken
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#include "config.h"
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#include "inttypes.h"
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#include "s5l8700.h"
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#include "adc.h"
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#include "adc-target.h"
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#include "kernel.h"
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/* Driver for the built-in ADC of the s5l8700
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The ADC is put into standby mode after each conversion.
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*/
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#define ADC_PRESCALER 100 /* 1MHz ADC clock, assuming 100 MHz PCLK */
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#define ADC_DEFAULT (1<<14) | /* prescale enable */ \
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((ADC_PRESCALER-1)<<6) | /* prescaler */ \
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(0<<3) | /* sel_mux */ \
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(0<<2) | /* stdbm */ \
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(0<<1) | /* read_start */ \
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(0<<0) /* enable start */ \
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static struct mutex adc_mtx;
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static struct semaphore adc_wakeup;
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void INT_ADC(void)
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{
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semaphore_release(&adc_wakeup);
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}
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unsigned short adc_read(int channel)
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{
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unsigned short data;
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mutex_lock(&adc_mtx);
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/* set channel and start conversion */
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ADCCON = ADC_DEFAULT |
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(channel << 3) |
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(1 << 0); /* enable start */
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/* wait for conversion */
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semaphore_wait(&adc_wakeup, TIMEOUT_BLOCK);
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/* get the converted data */
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data = ADCDAT0 & 0x3FF;
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/* put ADC back into standby */
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ADCCON |= (1 << 2);
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mutex_unlock(&adc_mtx);
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return data;
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}
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void adc_init(void)
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{
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mutex_init(&adc_mtx);
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semaphore_init(&adc_wakeup, 1, 0);
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/* enable clock to ADC */
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PWRCON &= ~(1 << 10);
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/* configure ADC and put in standby */
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ADCCON = ADC_DEFAULT | (1 << 2);
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/* configure conversion delay (use default) */
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ADCDLY = 0xFF;
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/* enable interrupt */
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INTMSK |= (1 << 31);
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}
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