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

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