static void process(void)
{
int val;
switch(touch_state)
{
case TOUCH_STATE_WAIT:
/* a touch has happened, check if it's still valid */
if(imx233_lradc_read_touch_detect())
enter_state(TOUCH_STATE_MEASURE_X);
else
{
old_touch_detect = false;
/* clear detect interrupt */
imx233_lradc_clear_touch_detect_irq();
}
break;
case TOUCH_STATE_MEASURE_X:
/* read value */
val = imx233_lradc_read_channel(touch_chan);
/* if value is too far from average, restart */
if(nr_samples > 0 && abs(val - touch_x) > DEBOUNCE_THRESHOLD)
nr_samples = 0;
touch_x = (touch_x * nr_samples + val) / (nr_samples + 1);
nr_samples++;
/* if we have enough samples, measure Y */
if(nr_samples > SAMPLES_THRESHOLD)
enter_state(TOUCH_STATE_MEASURE_Y);
else
imx233_lradc_kick_delay(touch_delay);
break;
case TOUCH_STATE_MEASURE_Y:
/* read value */
val = imx233_lradc_read_channel(touch_chan);
/* if value is too far from average, restart */
if(nr_samples > 0 && abs(val - touch_y) > DEBOUNCE_THRESHOLD)
nr_samples = 0;
touch_y = (touch_y * nr_samples + val) / (nr_samples + 1);
nr_samples++;
/* if we have enough samples, verify touch */
if(nr_samples > SAMPLES_THRESHOLD)
enter_state(TOUCH_STATE_VERIFY);
else
imx233_lradc_kick_delay(touch_delay);
break;
case TOUCH_STATE_VERIFY:
if(imx233_lradc_read_touch_detect())
{
old_touch_detect = true;
old_touch_x = touch_x;
old_touch_y = touch_y;
enter_state(TOUCH_STATE_MEASURE_X);
}
else
{
old_touch_detect = false;
enter_state(TOUCH_STATE_WAIT);
}
break;
}
}
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)
{
// 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;
}
