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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"
/* dedicate two channels to temperature sensing
* dedicate channel 7 to battery
* and channel 6 to vddio */
static int pmos_chan, nmos_chan;
static int battery_chan, vddio_chan;
static int battery_delay_chan;
void adc_init(void)
{
imx233_lradc_init();
/* reserve channels 6 for vddio and 7 for battery (special for conversion) */
battery_chan = 7;
vddio_chan = 6;
imx233_lradc_reserve_channel(battery_chan);
imx233_lradc_reserve_channel(vddio_chan);
/* reserve any channels for PMOS and NMOS */
pmos_chan = imx233_lradc_acquire_channel(TIMEOUT_NOBLOCK);
if(pmos_chan < 0) panicf("No LRADC channel for PMOS !");
nmos_chan = imx233_lradc_acquire_channel(TIMEOUT_NOBLOCK);
if(nmos_chan < 0) panicf("No LRADC channel for NMOS !");
/* setup them for the simplest use: no accumulation, no division*/
imx233_lradc_setup_channel(battery_chan, false, false, 0, HW_LRADC_CHANNEL_BATTERY);
imx233_lradc_setup_channel(vddio_chan, false, false, 0, HW_LRADC_CHANNEL_VDDIO);
imx233_lradc_setup_channel(nmos_chan, false, false, 0, HW_LRADC_CHANNEL_NMOS_THIN);
imx233_lradc_setup_channel(pmos_chan, false, false, 0, HW_LRADC_CHANNEL_PMOS_THIN);
/* setup delay channel for battery for automatic reading and scaling */
battery_delay_chan = 0;
imx233_lradc_reserve_delay(battery_delay_chan);
/* setup delay to trigger battery channel and retrigger itself.
* The counter runs at 2KHz so a delay of 200 will trigger 10
* conversions per seconds */
imx233_lradc_setup_delay(battery_delay_chan, 1 << battery_chan,
1 << battery_delay_chan, 0, 200);
imx233_lradc_kick_delay(battery_delay_chan);
/* enable automatic conversion, use Li-Ion type battery */
imx233_lradc_setup_battery_conversion(true, HW_LRADC_CONVERSION__SCALE_FACTOR__LI_ION);
}
int 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);
}
int adc_read_physical(int src)
{
int virt = imx233_lradc_acquire_channel(TIMEOUT_BLOCK);
// divide by two for wider ranger
imx233_lradc_setup_channel(virt, false, false, 0, src);
int val = adc_read_physical_ex(virt);
imx233_lradc_release_channel(virt);
return val;
}
unsigned short adc_read_virtual(int c)
{
switch(c)
{
case IMX233_ADC_BATTERY:
return adc_read_physical_ex(battery_chan);
case IMX233_ADC_VDDIO:
return adc_read_physical_ex(vddio_chan);
case IMX233_ADC_DIE_TEMP:
// do kelvin to celsius conversion
return imx233_lradc_sense_die_temperature(nmos_chan, pmos_chan) - 273;
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);
}
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