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

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Code shared between the different Qualcomm PMIC voltage ADCs
   4  */
   5
   6 #ifndef QCOM_VADC_COMMON_H
   7 #define QCOM_VADC_COMMON_H
   8
   9 #define VADC_CONV_TIME_MIN_US                   2000
  10 #define VADC_CONV_TIME_MAX_US                   2100
  11
  12 /* Min ADC code represents 0V */
  13 #define VADC_MIN_ADC_CODE                       0x6000
  14 /* Max ADC code represents full-scale range of 1.8V */
  15 #define VADC_MAX_ADC_CODE                       0xa800
  16
  17 #define VADC_ABSOLUTE_RANGE_UV                  625000
  18 #define VADC_RATIOMETRIC_RANGE                  1800
  19
  20 #define VADC_DEF_PRESCALING                     0 /* 1:1 */
  21 #define VADC_DEF_DECIMATION                     0 /* 512 */
  22 #define VADC_DEF_HW_SETTLE_TIME                 0 /* 0 us */
  23 #define VADC_DEF_AVG_SAMPLES                    0 /* 1 sample */
  24 #define VADC_DEF_CALIB_TYPE                     VADC_CALIB_ABSOLUTE
  25
  26 #define VADC_DECIMATION_MIN                     512
  27 #define VADC_DECIMATION_MAX                     4096
  28
  29 #define VADC_HW_SETTLE_DELAY_MAX                10000
  30 #define VADC_AVG_SAMPLES_MAX                    512
  31
  32 #define KELVINMIL_CELSIUSMIL                    273150
  33
  34 #define PMI_CHG_SCALE_1                         -138890
  35 #define PMI_CHG_SCALE_2                         391750000000LL
  36
  37 /**
  38  * struct vadc_map_pt - Map the graph representation for ADC channel
  39  * @x: Represent the ADC digitized code.
  40  * @y: Represent the physical data which can be temperature, voltage,
  41  *     resistance.
  42  */
  43 struct vadc_map_pt {
  44         s32 x;
  45         s32 y;
  46 };
  47
  48 /*
  49  * VADC_CALIB_ABSOLUTE: uses the 625mV and 1.25V as reference channels.
  50  * VADC_CALIB_RATIOMETRIC: uses the reference voltage (1.8V) and GND for
  51  * calibration.
  52  */
  53 enum vadc_calibration {
  54         VADC_CALIB_ABSOLUTE = 0,
  55         VADC_CALIB_RATIOMETRIC
  56 };
  57
  58 /**
  59  * struct vadc_linear_graph - Represent ADC characteristics.
  60  * @dy: numerator slope to calculate the gain.
  61  * @dx: denominator slope to calculate the gain.
  62  * @gnd: A/D word of the ground reference used for the channel.
  63  *
  64  * Each ADC device has different offset and gain parameters which are
  65  * computed to calibrate the device.
  66  */
  67 struct vadc_linear_graph {
  68         s32 dy;
  69         s32 dx;
  70         s32 gnd;
  71 };
  72
  73 /**
  74  * struct vadc_prescale_ratio - Represent scaling ratio for ADC input.
  75  * @num: the inverse numerator of the gain applied to the input channel.
  76  * @den: the inverse denominator of the gain applied to the input channel.
  77  */
  78 struct vadc_prescale_ratio {
  79         u32 num;
  80         u32 den;
  81 };
  82
  83 /**
  84  * enum vadc_scale_fn_type - Scaling function to convert ADC code to
  85  *                              physical scaled units for the channel.
  86  * SCALE_DEFAULT: Default scaling to convert raw adc code to voltage (uV).
  87  * SCALE_THERM_100K_PULLUP: Returns temperature in millidegC.
  88  *                               Uses a mapping table with 100K pullup.
  89  * SCALE_PMIC_THERM: Returns result in milli degree's Centigrade.
  90  * SCALE_XOTHERM: Returns XO thermistor voltage in millidegC.
  91  * SCALE_PMI_CHG_TEMP: Conversion for PMI CHG temp
  92  */
  93 enum vadc_scale_fn_type {
  94         SCALE_DEFAULT = 0,
  95         SCALE_THERM_100K_PULLUP,
  96         SCALE_PMIC_THERM,
  97         SCALE_XOTHERM,
  98         SCALE_PMI_CHG_TEMP,
  99 };
 100
 101 int qcom_vadc_scale(enum vadc_scale_fn_type scaletype,
 102                     const struct vadc_linear_graph *calib_graph,
 103                     const struct vadc_prescale_ratio *prescale,
 104                     bool absolute,
 105                     u16 adc_code, int *result_mdec);
 106
 107 int qcom_vadc_decimation_from_dt(u32 value);
 108
 109 #endif /* QCOM_VADC_COMMON_H */