rockbox/firmware/target/coldfire/mpio/adc-mpio.c
Marcin Bukat e94d1b0ab0 MPIO HD200/HD300: Decrease ADC scanrate.
The adclk is decreased 4x. This solves problems with battery
readout drop during system startup.

Change-Id: I46d7c4b9ffcfdc812a6dd2a932c9e397d33c1168
2012-01-24 12:05:07 +01:00

77 lines
2.1 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2010 Marcin Bukat
*
* 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 "cpu.h"
#include "system.h"
#include "kernel.h"
#include "thread.h"
#include "adc.h"
volatile unsigned short adc_data[NUM_ADC_CHANNELS] IBSS_ATTR;
void ADC(void) __attribute__ ((interrupt_handler,section(".icode")));
void ADC(void)
{
static unsigned char channel IBSS_ATTR;
/* read current value */
adc_data[(channel&0x03)] = ADVALUE;
/* switch channel
*
* set source remark
* ADCONFIG is 16bit wide so we have to shift data by 16bits left
* thats why we shift <<24 instead of <<8
*/
channel++;
and_l(~(0x03<<24),&ADCONFIG);
or_l( (((channel&0x03) << 8 )|(1<<7))<<16, &ADCONFIG);
}
unsigned short adc_scan(int channel)
{
/* maybe we can drop &0x03 part */
return adc_data[(channel&0x03)];
}
void adc_init(void)
{
/* GPIO38 GPIO39 */
and_l(~((1<<6)|(1<<7)), &GPIO1_FUNCTION);
/* ADOUT_SEL = 01
* SOURCE SELECT = 000
* CLEAR INTERRUPT FLAG
* ENABLE INTERRUPT = 1
* ADOUT_DRIVE = 00
* ADCLK_SEL = 011 (busclk/64)
*/
ADCONFIG = (1<<10)|(1<<7)|(1<<6)|0x06;
/* ADC interrupt level 4.0 */
or_l((4<<28), &INTPRI8);
/* let the interrupt handler fill readout array */
sleep(HZ/10);
}