linux/drivers/iio/adc/qcom-vadc-common.h

110 lines
3.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Code shared between the different Qualcomm PMIC voltage ADCs
*/
#ifndef QCOM_VADC_COMMON_H
#define QCOM_VADC_COMMON_H
#define VADC_CONV_TIME_MIN_US 2000
#define VADC_CONV_TIME_MAX_US 2100
/* Min ADC code represents 0V */
#define VADC_MIN_ADC_CODE 0x6000
/* Max ADC code represents full-scale range of 1.8V */
#define VADC_MAX_ADC_CODE 0xa800
#define VADC_ABSOLUTE_RANGE_UV 625000
#define VADC_RATIOMETRIC_RANGE 1800
#define VADC_DEF_PRESCALING 0 /* 1:1 */
#define VADC_DEF_DECIMATION 0 /* 512 */
#define VADC_DEF_HW_SETTLE_TIME 0 /* 0 us */
#define VADC_DEF_AVG_SAMPLES 0 /* 1 sample */
#define VADC_DEF_CALIB_TYPE VADC_CALIB_ABSOLUTE
#define VADC_DECIMATION_MIN 512
#define VADC_DECIMATION_MAX 4096
#define VADC_HW_SETTLE_DELAY_MAX 10000
#define VADC_AVG_SAMPLES_MAX 512
#define KELVINMIL_CELSIUSMIL 273150
#define PMI_CHG_SCALE_1 -138890
#define PMI_CHG_SCALE_2 391750000000LL
/**
* struct vadc_map_pt - Map the graph representation for ADC channel
* @x: Represent the ADC digitized code.
* @y: Represent the physical data which can be temperature, voltage,
* resistance.
*/
struct vadc_map_pt {
s32 x;
s32 y;
};
/*
* VADC_CALIB_ABSOLUTE: uses the 625mV and 1.25V as reference channels.
* VADC_CALIB_RATIOMETRIC: uses the reference voltage (1.8V) and GND for
* calibration.
*/
enum vadc_calibration {
VADC_CALIB_ABSOLUTE = 0,
VADC_CALIB_RATIOMETRIC
};
/**
* struct vadc_linear_graph - Represent ADC characteristics.
* @dy: numerator slope to calculate the gain.
* @dx: denominator slope to calculate the gain.
* @gnd: A/D word of the ground reference used for the channel.
*
* Each ADC device has different offset and gain parameters which are
* computed to calibrate the device.
*/
struct vadc_linear_graph {
s32 dy;
s32 dx;
s32 gnd;
};
/**
* struct vadc_prescale_ratio - Represent scaling ratio for ADC input.
* @num: the inverse numerator of the gain applied to the input channel.
* @den: the inverse denominator of the gain applied to the input channel.
*/
struct vadc_prescale_ratio {
u32 num;
u32 den;
};
/**
* enum vadc_scale_fn_type - Scaling function to convert ADC code to
* physical scaled units for the channel.
* SCALE_DEFAULT: Default scaling to convert raw adc code to voltage (uV).
* SCALE_THERM_100K_PULLUP: Returns temperature in millidegC.
* Uses a mapping table with 100K pullup.
* SCALE_PMIC_THERM: Returns result in milli degree's Centigrade.
* SCALE_XOTHERM: Returns XO thermistor voltage in millidegC.
* SCALE_PMI_CHG_TEMP: Conversion for PMI CHG temp
*/
enum vadc_scale_fn_type {
SCALE_DEFAULT = 0,
SCALE_THERM_100K_PULLUP,
SCALE_PMIC_THERM,
SCALE_XOTHERM,
SCALE_PMI_CHG_TEMP,
};
int qcom_vadc_scale(enum vadc_scale_fn_type scaletype,
const struct vadc_linear_graph *calib_graph,
const struct vadc_prescale_ratio *prescale,
bool absolute,
u16 adc_code, int *result_mdec);
int qcom_vadc_decimation_from_dt(u32 value);
#endif /* QCOM_VADC_COMMON_H */