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drivers: sensor: ina237: add high-precision mode

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The current-shunt calibration requires a factor of 4x if high-precision
mode is selected.

Signed-off-by: Eric Holmberg <eric.holmberg@northriversystems.co.nz>
This commit is contained in:
Eric Holmberg 2023-07-23 21:01:55 +12:00 • committed by Maureen Helm
commit a70d056513
6 changed files with 112 additions and 7 deletions
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25
drivers/sensor/ina23x/ina237.c
View file

@ -22,8 +22,8 @@ LOG_MODULE_REGISTER(INA237, CONFIG_SENSOR_LOG_LEVEL);
/** @brief The LSB value for the bus voltage register, in microvolts/LSB. */
#define INA237_BUS_VOLTAGE_TO_uV(x) ((x) * 3125U)
/** @brief Power scaling (scaled by 10) */
#define INA237_POWER_SCALING 2
/** @brief Power scaling (need factor of 0.2) */
#define INA237_POWER_TO_uW(x) ((x) / 5ULL)
/**
* @brief Scale die temperture from 0.125 degC/bit to micro-degrees C
@ -37,6 +37,12 @@ static void micro_s32_to_sensor_value(struct sensor_value *val, int32_t value_mi
val->val2 = value_microX % 1000000L;
}
static void micro_u64_to_sensor_value(struct sensor_value *val, uint64_t value_microX)
{
val->val1 = value_microX / 1000000U;
val->val2 = value_microX % 1000000U;
}
static int ina237_channel_get(const struct device *dev, enum sensor_channel chan,
struct sensor_value *val)
{
@ -54,9 +60,9 @@ static int ina237_channel_get(const struct device *dev, enum sensor_channel chan
break;
case SENSOR_CHAN_POWER:
/* see datasheet "Current and Power calculations" section */
micro_s32_to_sensor_value(val,
(data->power * INA237_POWER_SCALING * config->current_lsb) / 10000U);
/* power in uW is power_reg * current_lsb * 0.2 */
micro_u64_to_sensor_value(val,
INA237_POWER_TO_uW((uint64_t)data->power * config->current_lsb));
break;
case SENSOR_CHAN_DIE_TEMP:
@ -364,6 +370,10 @@ static const struct sensor_driver_api ina237_driver_api = {
.channel_get = ina237_channel_get,
};
/* Shunt calibration must be muliplied by 4 if high-prevision mode is selected */
#define CAL_PRECISION_MULTIPLIER(config) \
(((config & INA237_CFG_HIGH_PRECISION) >> 4) * 3 + 1)
#define INA237_DRIVER_INIT(inst) \
static struct ina237_data ina237_data_##inst; \
static const struct ina237_config ina237_config_##inst = { \
@ -376,8 +386,9 @@ static const struct sensor_driver_api ina237_driver_api = {
(DT_INST_ENUM_IDX(inst, temp_conversion_time_us) << 3) | \
DT_INST_ENUM_IDX(inst, avg_count), \
.current_lsb = DT_INST_PROP(inst, current_lsb_microamps), \
.cal = INA237_CAL_SCALING * DT_INST_PROP(inst, current_lsb_microamps) * \
DT_INST_PROP(inst, rshunt_micro_ohms) / 10000000000ULL, \
.cal = CAL_PRECISION_MULTIPLIER(DT_INST_PROP(inst, config)) * \
INA237_CAL_SCALING * DT_INST_PROP(inst, current_lsb_microamps) * \
DT_INST_PROP(inst, rshunt_micro_ohms) / 10000000ULL, \
.alert_config = DT_INST_PROP_OR(inst, alert_config, 0x01), \
.alert_gpio = GPIO_DT_SPEC_INST_GET_OR(inst, alert_gpios, {0}), \
}; \

2
drivers/sensor/ina23x/ina237.h
View file

@ -17,6 +17,8 @@
#include <zephyr/drivers/sensor.h>
#define INA237_REG_CONFIG 0x00
#define INA237_CFG_HIGH_PRECISION BIT(4)
#define INA237_REG_ADC_CONFIG 0x01
#define INA237_REG_CALIB 0x02
#define INA237_REG_SHUNT_VOLT 0x04