d74117450c
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17031 a1c6a512-1295-4272-9138-f99709370657
106 lines
2.6 KiB
C
106 lines
2.6 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) 2007 by Dave Chapman
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*
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* All files in this archive are subject to the GNU General Public License.
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* See the file COPYING in the source tree root for full license agreement.
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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 "cpu.h"
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#include "system.h"
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#include "kernel.h"
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#include "thread.h"
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#include "string.h"
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#include "adc.h"
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static unsigned short adcdata[8];
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#ifndef BOOTLOADER
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/* Tick task */
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static void adc_tick(void)
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{
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int i;
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PCLK_ADC |= PCK_EN; /* Enable ADC clock */
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/* Start converting the first 4 channels */
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for (i = 0; i < 4; i++)
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ADCCON = i;
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}
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/* IRQ handler */
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void ADC(void)
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{
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int num;
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uint32_t adc_status;
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do
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{
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adc_status = ADCSTATUS;
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num = (adc_status>>24) & 7;
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if (num) adcdata[(adc_status >> 16) & 0x7] = adc_status & 0x3ff;
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} while (num);
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PCLK_ADC &= ~PCK_EN; /* Disable ADC clock */
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}
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#endif /* BOOTLOADER */
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unsigned short adc_read(int channel)
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{
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#ifdef BOOTLOADER
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/* IRQs aren't enabled in the bootloader - just do the read directly */
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int i;
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uint32_t adc_status;
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PCLK_ADC |= PCK_EN; /* Enable ADC clock */
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/* Start converting the first 4 channels */
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for (i = 0; i < 4; i++)
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ADCCON = i;
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/* Now read the values back */
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for (i=0; i < 4; i++)
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{
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/* Wait for data to become stable */
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while ((ADCDATA & 0x1) == 0);
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adc_status = ADCSTATUS;
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adcdata[(adc_status >> 16) & 0x7] = adc_status & 0x3ff;
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}
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PCLK_ADC &= ~PCK_EN; /* Disable ADC clock */
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#endif
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return adcdata[channel];
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}
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void adc_init(void)
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{
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/* consider configuring PCK_ADC source here */
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ADCCON = (1<<4); /* Enter standby mode */
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ADCCFG |= 0x00000003; /* Single-mode, auto power-down */
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#ifndef BOOTLOADER
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ADCCFG |= (1<<3); /* Request IRQ on ADC completion */
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IEN |= ADC_IRQ_MASK; /* Unmask ADC IRQs */
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tick_add_task(adc_tick);
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sleep(2); /* Ensure valid readings when adc_init returns */
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#endif
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}
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