From 63fb21afc1f5b2af746f332710491c61e2ad6d74 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Wed, 28 Aug 2024 17:21:41 -0700 Subject: [PATCH] hwmon: (ina2xx) Use shunt voltage to calculate current Since the shunt voltage and the current register report the same values when the chip is calibrated, we can calculate the current directly from the shunt voltage without relying on chip calibration. With this change, the current register is no longer accessed. Its register address is only used to indicate if reading or writing current or shunt voltage is desired when accessing registers. Reviewed-by: Tzung-Bi Shih Signed-off-by: Guenter Roeck --- drivers/hwmon/ina2xx.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c index 10c8c475c634..f0fa6d073627 100644 --- a/drivers/hwmon/ina2xx.c +++ b/drivers/hwmon/ina2xx.c @@ -480,6 +480,8 @@ static int ina2xx_curr_read(struct device *dev, u32 attr, long *val) { struct ina2xx_data *data = dev_get_drvdata(dev); struct regmap *regmap = data->regmap; + unsigned int regval; + int ret; /* * While the chips supported by this driver do not directly support @@ -492,7 +494,17 @@ static int ina2xx_curr_read(struct device *dev, u32 attr, long *val) */ switch (attr) { case hwmon_curr_input: - return ina2xx_read_init(dev, INA2XX_CURRENT, val); + /* + * Since the shunt voltage and the current register report the + * same values when the chip is calibrated, we can calculate + * the current directly from the shunt voltage without relying + * on chip calibration. + */ + ret = regmap_read(regmap, INA2XX_SHUNT_VOLTAGE, ®val); + if (ret) + return ret; + *val = ina2xx_get_value(data, INA2XX_CURRENT, regval); + return 0; case hwmon_curr_lcrit: return ina226_alert_limit_read(data, INA226_SHUNT_UNDER_VOLTAGE_MASK, INA2XX_CURRENT, val);