rockbox/firmware/target/arm/tcc780x/adc-tcc780x.c
Rob Purchase 47ea030e2e Initial Cowon D2 commit:
* bootloader test program (basic LCD & button drivers, reads touchscreen)
* work-in-progress stubs for main build


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@16090 a1c6a512-1295-4272-9138-f99709370657
2008-01-14 22:04:48 +00:00

76 lines
2.3 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2007 by Dave Chapman
*
* 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"
/*
TODO: We probably want to do this on the timer interrupt once we get
interrupts going - see the sh-adc.c implementation for an example which
looks like it should work well with the TCC77x.
Also, this code is practically identical between 77x & 780x targets.
Should probably find a common location to avoid the duplication.
*/
static unsigned short adcdata[8];
static void adc_do_read(void)
{
int i;
uint32_t adc_status;
PCLK_ADC |= PCK_EN; /* Enable ADC clock */
/* Start converting the first 4 channels */
for (i = 0; i < 4; i++)
ADCCON = i;
/* Wait for data to become stable */
while ((ADCDATA & 0x1) == 0);
/* Now read the values back */
for (i=0;i < 4; i++) {
adc_status = ADCSTATUS;
adcdata[(adc_status >> 16) & 0x7] = adc_status & 0x3ff;
}
PCLK_ADC &= ~PCK_EN; /* Disable ADC clock */
}
unsigned short adc_read(int channel)
{
/* Either move this to an interrupt routine, or only perform the read if
the last call was X length of time ago. */
adc_do_read();
return adcdata[channel];
}
void adc_init(void)
{
/* consider configuring PCK_ADC source here */
ADCCON = (1<<4); /* Leave standby mode */
ADCCFG |= 0x00000003; /* Single-mode, auto power-down */
}