rockbox/firmware/target/arm/imx233/adc-imx233.c
Amaury Pouly f4fdf1ffe2 imx233: fix lradc/adc for stmp3600 and stmp3700
The lradc architecture of the stmp3600 is rather different:
only channels 6 and 7 have configurable source and we need to
take care when allocating channels so that we can actually
measure the right channel! Delegate die temperature sensing to
the power block on stmp3600.

Change-Id: I0860eb4ea98240facc3d4a19d61684eca5f630cc
2013-06-17 00:29:25 +02:00

104 lines
3.4 KiB
C

/***************************************************************************
* __________ __ ___.
* 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 "adc-imx233.h"
#include "power-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(src, 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(LRADC_SRC_VDDIO, false);
#if IMX233_SUBTARGET >= 3700
case IMX233_ADC_VDD5V:
/* Vdd5V pin has a builtin 4:1 divide */
return adc_read_physical(LRADC_SRC_5V, false) * 2;
#endif
case IMX233_ADC_DIE_TEMP:
{
#if IMX233_SUBTARGET >= 3700
// don't block on second channel otherwise we might deadlock !
int nmos_chan = imx233_lradc_acquire_channel(LRADC_SRC_NMOS_THIN, TIMEOUT_BLOCK);
int pmos_chan = imx233_lradc_acquire_channel(LRADC_SRC_PMOS_THIN, 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);
#else
int min, max, val;
if(imx233_power_sense_die_temperature(&min, &max) < 0)
val = -1;
else
val = (max + min) / 2;
#endif
return val;
}
#ifdef IMX233_BATT_TEMP_SENSOR
case IMX233_ADC_BATT_TEMP:
{
int virt = imx233_lradc_acquire_channel(IMX233_BATT_TEMP_SENSOR, TIMEOUT_BLOCK);
int val = imx233_lradc_sense_ext_temperature(virt, IMX233_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);
}