Add the BAT_THERM channels with millivolt as output, which can then be used along with information regarding the NTC in the battery, to get the actual battery temperature.
A static lookup table in the ADC driver won't work since different devices have different Ohm and Beta values in their battery NTCs, for example a NTC can be 10kOhm & B=3435K. Signed-off-by: Luca Weiss <[email protected]> --- drivers/iio/adc/qcom-spmi-adc5.c | 6 ++++++ drivers/iio/adc/qcom-vadc-common.c | 16 ++++++++++++++++ include/linux/iio/adc/qcom-vadc-common.h | 3 +++ 3 files changed, 25 insertions(+) diff --git a/drivers/iio/adc/qcom-spmi-adc5.c b/drivers/iio/adc/qcom-spmi-adc5.c index af3c2f659f5e..6ad75368d3a3 100644 --- a/drivers/iio/adc/qcom-spmi-adc5.c +++ b/drivers/iio/adc/qcom-spmi-adc5.c @@ -543,6 +543,12 @@ static const struct adc5_channels adc5_chans_pmic[ADC5_MAX_CHANNEL] = { SCALE_HW_CALIB_DEFAULT) [ADC5_XO_THERM_100K_PU] = ADC5_CHAN_TEMP("xo_therm", 0, SCALE_HW_CALIB_XOTHERM) + [ADC5_BAT_THERM_30K_PU] = ADC5_CHAN_VOLT("bat_therm_30k_pu", 0, + SCALE_HW_CALIB_THERM_VOLT) + [ADC5_BAT_THERM_100K_PU] = ADC5_CHAN_VOLT("bat_therm_100k_pu", 0, + SCALE_HW_CALIB_THERM_VOLT) + [ADC5_BAT_THERM_400K_PU] = ADC5_CHAN_VOLT("bat_therm_400k_pu", 0, + SCALE_HW_CALIB_THERM_VOLT) [ADC5_BAT_ID_100K_PU] = ADC5_CHAN_TEMP("bat_id", 0, SCALE_HW_CALIB_DEFAULT) [ADC5_AMUX_THM1_100K_PU] = ADC5_CHAN_TEMP("amux_thm1_100k_pu", 0, diff --git a/drivers/iio/adc/qcom-vadc-common.c b/drivers/iio/adc/qcom-vadc-common.c index b03cf584b165..09a13e2b0ef4 100644 --- a/drivers/iio/adc/qcom-vadc-common.c +++ b/drivers/iio/adc/qcom-vadc-common.c @@ -309,6 +309,10 @@ static int qcom_vadc_scale_hw_calib_therm( const struct u32_fract *prescale, const struct adc5_data *data, u16 adc_code, int *result_mdec); +static int qcom_vadc_scale_hw_calib_therm_volt( + const struct u32_fract *prescale, + const struct adc5_data *data, + u16 adc_code, int *result_mdec); static int qcom_vadc7_scale_hw_calib_therm( const struct u32_fract *prescale, const struct adc5_data *data, @@ -333,6 +337,7 @@ static int qcom_vadc7_scale_hw_calib_die_temp( static const struct qcom_adc5_scale_type scale_adc5_fn[] = { [SCALE_HW_CALIB_DEFAULT] = {qcom_vadc_scale_hw_calib_volt}, [SCALE_HW_CALIB_THERM_100K_PULLUP] = {qcom_vadc_scale_hw_calib_therm}, + [SCALE_HW_CALIB_THERM_VOLT] = {qcom_vadc_scale_hw_calib_therm_volt}, [SCALE_HW_CALIB_XOTHERM] = {qcom_vadc_scale_hw_calib_therm}, [SCALE_HW_CALIB_THERM_100K_PU_PM7] = { qcom_vadc7_scale_hw_calib_therm}, @@ -583,6 +588,17 @@ static int qcom_vadc_scale_hw_calib_therm( voltage, result_mdec); } +static int qcom_vadc_scale_hw_calib_therm_volt( + const struct u32_fract *prescale, + const struct adc5_data *data, + u16 adc_code, int *result_uv) +{ + *result_uv = qcom_vadc_scale_code_voltage_factor(adc_code, + prescale, data, 1000); + + return 0; +} + static int qcom_vadc_scale_hw_calib_die_temp( const struct u32_fract *prescale, const struct adc5_data *data, diff --git a/include/linux/iio/adc/qcom-vadc-common.h b/include/linux/iio/adc/qcom-vadc-common.h index aa21b032e861..3ae091fa93d7 100644 --- a/include/linux/iio/adc/qcom-vadc-common.h +++ b/include/linux/iio/adc/qcom-vadc-common.h @@ -93,6 +93,8 @@ struct vadc_linear_graph { * voltage (uV) with hardware applied offset/slope values to adc code. * SCALE_HW_CALIB_THERM_100K_PULLUP: Returns temperature in millidegC using * lookup table. The hardware applies offset/slope to adc code. + * SCALE_HW_CALIB_THERM_VOLT: Returns voltage in uV of a temperature channel. + * The hardware applies offset/slope to adc code. * SCALE_HW_CALIB_XOTHERM: Returns XO thermistor voltage in millidegC using * 100k pullup. The hardware applies offset/slope to adc code. * SCALE_HW_CALIB_THERM_100K_PU_PM7: Returns temperature in millidegC using @@ -114,6 +116,7 @@ enum vadc_scale_fn_type { SCALE_PMI_CHG_TEMP, SCALE_HW_CALIB_DEFAULT, SCALE_HW_CALIB_THERM_100K_PULLUP, + SCALE_HW_CALIB_THERM_VOLT, SCALE_HW_CALIB_XOTHERM, SCALE_HW_CALIB_THERM_100K_PU_PM7, SCALE_HW_CALIB_PMIC_THERM, -- 2.51.0
