rockbox/firmware/target/arm/imx233/adc-imx233.c

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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2011 by Amaury Pouly
*
* 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 "adc.h"
#include "adc-target.h"
#include "system.h"
#include "adc-imx233.h"
void adc_init(void)
{
}
static short adc_read_physical_ex(int virt)
{
imx233_lradc_clear_channel(virt);
imx233_lradc_kick_channel(virt);
imx233_lradc_wait_channel(virt);
return imx233_lradc_read_channel(virt);
}
static short adc_read_physical(int src, bool div2)
{
int virt = imx233_lradc_acquire_channel(TIMEOUT_BLOCK);
// divide by two for wider ranger
imx233_lradc_setup_channel(virt, div2, false, 0, src);
int val = adc_read_physical_ex(virt);
imx233_lradc_release_channel(virt);
return val;
}
static short adc_read_virtual(int c)
{
switch(c)
{
case IMX233_ADC_BATTERY:
return imx233_lradc_read_battery_voltage();
case IMX233_ADC_VDDIO:
/* VddIO pin has a builtin 2:1 divide */
return adc_read_physical(HW_LRADC_CHANNEL_VDDIO, false);
case IMX233_ADC_VDD5V:
/* Vdd5V pin has a builtin 4:1 divide */
return adc_read_physical(HW_LRADC_CHANNEL_5V, false) * 2;
case IMX233_ADC_DIE_TEMP:
{
// don't block on second channel otherwise we might deadlock !
int nmos_chan = imx233_lradc_acquire_channel(TIMEOUT_BLOCK);
int pmos_chan = imx233_lradc_acquire_channel(TIMEOUT_NOBLOCK);
int val = 0;
if(pmos_chan >= 0)
{
val = imx233_lradc_sense_die_temperature(nmos_chan, pmos_chan) - 273;
imx233_lradc_release_channel(pmos_chan);
}
imx233_lradc_release_channel(nmos_chan);
return val;
}
#ifdef IMX233_ADC_BATT_TEMP_SENSOR
case IMX233_ADC_BATT_TEMP:
{
int virt = imx233_lradc_acquire_channel(TIMEOUT_BLOCK);
int val = imx233_lradc_sense_ext_temperature(virt, IMX233_ADC_BATT_TEMP_SENSOR);
imx233_lradc_release_channel(virt);
return val;
}
#endif
default:
return 0;
}
}
unsigned short adc_read(int channel)
{
int c = imx233_adc_mapping[channel];
if(c < 0)
return adc_read_virtual(c);
else
return adc_read_physical(c, true);
}