Commit d153106b authored by Guenter Roeck's avatar Guenter Roeck
Browse files

hwmon: (ina238) Only configure calibration and shunt registers if needed 



Prepare for supporting chips with internal shunt resistor by only setting
calibration and shunt resistor registers if no current LSB is configured.

Do not display a log message during probe if a chip does not have shunt
and gain registers since those would otherwise display 0, and a message
just indicating that the driver was loaded would be just noise.

Reviewed-by: default avatarChris Packham <chris.packham@alliedtelesis.co.nz>
Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz> # INA780
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 807e315b

drivers/hwmon/ina238.c

+42 −40
Original line number Diff line number Diff line
@@ -745,6 +745,12 @@ static int ina238_probe(struct i2c_client *client) 
		return PTR_ERR(data->regmap);

	}



	/* Setup CONFIG register */

	config = data->config->config_default;

	if (data->config->current_lsb) {

		data->voltage_lsb[0] = INA238_SHUNT_VOLTAGE_LSB;

		data->current_lsb = data->config->current_lsb;

	} else {

		/* load shunt value */

		if (device_property_read_u32(dev, "shunt-resistor", &data->rshunt) < 0)

			data->rshunt = INA238_RSHUNT_DEFAULT;
@@ -761,16 +767,26 @@ static int ina238_probe(struct i2c_client *client) 
			return -EINVAL;

		}



	/* Setup CONFIG register */

	config = data->config->config_default;

		/* Setup SHUNT_CALIBRATION register with fixed value */

		ret = regmap_write(data->regmap, INA238_SHUNT_CALIBRATION,

				   INA238_CALIBRATION_VALUE);

		if (ret < 0) {

			dev_err(dev, "error configuring the device: %d\n", ret);

			return -ENODEV;

		}

		if (chip == sq52206) {

		if (data->gain == 1)

			config |= SQ52206_CONFIG_ADCRANGE_HIGH; /* ADCRANGE = 10/11 is /1 */

		else if (data->gain == 2)

			config |= SQ52206_CONFIG_ADCRANGE_LOW; /* ADCRANGE = 01 is /2 */

	} else if (data->gain == 1) {

		config |= INA238_CONFIG_ADCRANGE; /* ADCRANGE = 1 is /1 */

			if (data->gain == 1)		/* ADCRANGE = 10/11 is /1 */

				config |= SQ52206_CONFIG_ADCRANGE_HIGH;

			else if (data->gain == 2)	/* ADCRANGE = 01 is /2 */

				config |= SQ52206_CONFIG_ADCRANGE_LOW;

		} else if (data->gain == 1) {		/* ADCRANGE = 1 is /1 */

			config |= INA238_CONFIG_ADCRANGE;

		}

		data->voltage_lsb[0] = INA238_SHUNT_VOLTAGE_LSB * data->gain / 4;

		data->current_lsb = DIV_U64_ROUND_CLOSEST(250ULL * INA238_FIXED_SHUNT * data->gain,

							  data->rshunt);

	}



	ret = regmap_write(data->regmap, INA238_CONFIG, config);

	if (ret < 0) {

		dev_err(dev, "error configuring the device: %d\n", ret);
@@ -785,14 +801,6 @@ static int ina238_probe(struct i2c_client *client) 
		return -ENODEV;

	}



	/* Setup SHUNT_CALIBRATION register with fixed value */

	ret = regmap_write(data->regmap, INA238_SHUNT_CALIBRATION,

			   INA238_CALIBRATION_VALUE);

	if (ret < 0) {

		dev_err(dev, "error configuring the device: %d\n", ret);

		return -ENODEV;

	}



	/* Setup alert/alarm configuration */

	config = INA238_DIAG_ALERT_DEFAULT;

	if (device_property_read_bool(dev, "ti,alert-polarity-active-high"))
@@ -804,15 +812,8 @@ static int ina238_probe(struct i2c_client *client) 
		return -ENODEV;

	}



	data->voltage_lsb[0] = INA238_SHUNT_VOLTAGE_LSB * data->gain / 4;

	data->voltage_lsb[1] = data->config->bus_voltage_lsb;



	if (data->config->current_lsb)

		data->current_lsb = data->config->current_lsb;

	else

		data->current_lsb = DIV_U64_ROUND_CLOSEST(250ULL * INA238_FIXED_SHUNT * data->gain,

							  data->rshunt);



	data->power_lsb = DIV_ROUND_CLOSEST(data->current_lsb *

					    data->config->power_calculate_factor,

					    100);
@@ -824,6 +825,7 @@ static int ina238_probe(struct i2c_client *client) 
	if (IS_ERR(hwmon_dev))

		return PTR_ERR(hwmon_dev);



	if (data->rshunt)

		dev_info(dev, "power monitor %s (Rshunt = %u uOhm, gain = %u)\n",

			 client->name, data->rshunt, data->gain);