void imx233_lradc_init(void)
{
arbiter_init(&channel_arbiter, HW_LRADC_NUM_CHANNELS);
arbiter_init(&delay_arbiter, HW_LRADC_NUM_DELAYS);
// enable block
imx233_reset_block(&HW_LRADC_CTRL0);
// disable ground ref
__REG_CLR(HW_LRADC_CTRL0) = HW_LRADC_CTRL0__ONCHIP_GROUNDREF;
// disable temperature sensors
__REG_CLR(HW_LRADC_CTRL2) = HW_LRADC_CTRL2__TEMP_SENSOR_IENABLE0 |
HW_LRADC_CTRL2__TEMP_SENSOR_IENABLE1;
__REG_SET(HW_LRADC_CTRL2) = HW_LRADC_CTRL2__TEMPSENSE_PWD;
// set frequency
__REG_CLR(HW_LRADC_CTRL3) = HW_LRADC_CTRL3__CYCLE_TIME_BM;
__REG_SET(HW_LRADC_CTRL3) = HW_LRADC_CTRL3__CYCLE_TIME__6MHz;
// setup battery
battery_chan = 7;
imx233_lradc_reserve_channel(battery_chan);
/* setup them for the simplest use: no accumulation, no division*/
imx233_lradc_setup_channel(battery_chan, false, false, 0, HW_LRADC_CHANNEL_BATTERY);
/* 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 imx233_lradc_sense_ext_temperature(int chan, int sensor)
{
#define EXT_TEMP_ACC_COUNT 5
/* setup channel */
imx233_lradc_setup_channel(chan, false, false, 0, sensor);
/* set current source to 300µA */
imx233_lradc_set_temp_isrc(sensor, HW_LRADC_CTRL2__TEMP_ISRC__300uA);
/* read value and accumulate */
int a = 0;
for(int i = 0; i < EXT_TEMP_ACC_COUNT; i++)
{
imx233_lradc_clear_channel(chan);
imx233_lradc_kick_channel(chan);
imx233_lradc_wait_channel(chan);
a += imx233_lradc_read_channel(chan);
}
/* setup channel for small accumulation */
/* set current source to 20µA */
imx233_lradc_set_temp_isrc(sensor, HW_LRADC_CTRL2__TEMP_ISRC__20uA);
/* read value */
int b = 0;
for(int i = 0; i < EXT_TEMP_ACC_COUNT; i++)
{
imx233_lradc_clear_channel(chan);
imx233_lradc_kick_channel(chan);
imx233_lradc_wait_channel(chan);
b += imx233_lradc_read_channel(chan);
}
/* disable sensor current */
imx233_lradc_set_temp_isrc(sensor, HW_LRADC_CTRL2__TEMP_ISRC__0uA);
return (abs(b - a) / EXT_TEMP_ACC_COUNT) * 1104 / 1000;
}
int imx233_lradc_sense_die_temperature(int nmos_chan, int pmos_chan)
{
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);
// mux sensors
__REG_CLR(HW_LRADC_CTRL2) = HW_LRADC_CTRL2__TEMPSENSE_PWD;
imx233_lradc_clear_channel(nmos_chan);
imx233_lradc_clear_channel(pmos_chan);
// schedule both channels
imx233_lradc_kick_channel(nmos_chan);
imx233_lradc_kick_channel(pmos_chan);
// wait completion
imx233_lradc_wait_channel(nmos_chan);
imx233_lradc_wait_channel(pmos_chan);
// mux sensors
__REG_SET(HW_LRADC_CTRL2) = HW_LRADC_CTRL2__TEMPSENSE_PWD;
// do the computation
int diff = imx233_lradc_read_channel(nmos_chan) - imx233_lradc_read_channel(pmos_chan);
// return diff * 1.012 / 4
return (diff * 1012) / 4000;
}
static void kick_measure(bool pull_x, bool pull_y, bool detect, int lradc_phys)
{
/* setup measurement: x- pull down and x+ pull up */
imx233_lradc_setup_touch(pull_x, pull_y, pull_x, pull_y, detect);
imx233_lradc_enable_touch_detect_irq(false);
imx233_lradc_enable_channel_irq(touch_chan, true);
/* measure channel, no accumulation */
imx233_lradc_setup_channel(touch_chan, false, false, 0, lradc_phys);
/* use a delay */
imx233_lradc_setup_delay(touch_delay, 1 << touch_chan, 0, 0, 8);
imx233_lradc_kick_delay(touch_delay);
}
void lradc_setup_channels_for_polling()
{
unsigned char i;
int trigger_bitmap = 0;
imx233_lradc_init();
for (i=0; i<MAX_USER_LRADC; i++) {
imx233_lradc_setup_channel(i, 1, 0, 0, i);
imx233_lradc_enable_channel_irq(i, false);
imx233_lradc_clear_channel_irq(i);
trigger_bitmap |= 1<<i;
}
imx233_lradc_setup_delay(LRADC_DELAY_INDEX, trigger_bitmap, 1<<LRADC_DELAY_INDEX, 0, 100);
imx233_lradc_kick_delay(LRADC_DELAY_INDEX);
}