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

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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: Chris Packham <chris.packham@alliedtelesis.co.nz>
Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz> # INA780
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Guenter Roeck 2025-08-31 09:39:53 -07:00
parent 807e315bf9
commit d153106bd4
1 changed files with 42 additions and 40 deletions
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82
drivers/hwmon/ina238.c
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@ -745,32 +745,48 @@ static int ina238_probe(struct i2c_client *client)
return PTR_ERR(data->regmap);
}
/* load shunt value */
if (device_property_read_u32(dev, "shunt-resistor", &data->rshunt) < 0)
data->rshunt = INA238_RSHUNT_DEFAULT;
if (data->rshunt == 0) {
dev_err(dev, "invalid shunt resister value %u\n", data->rshunt);
return -EINVAL;
}
/* load shunt gain value */
if (device_property_read_u32(dev, "ti,shunt-gain", &data->gain) < 0)
data->gain = 4; /* Default of ADCRANGE = 0 */
if (data->gain != 1 && data->gain != 2 && data->gain != 4) {
dev_err(dev, "invalid shunt gain value %u\n", data->gain);
return -EINVAL;
}
/* Setup CONFIG register */
config = data->config->config_default;
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->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;
if (data->rshunt == 0) {
dev_err(dev, "invalid shunt resister value %u\n", data->rshunt);
return -EINVAL;
}
/* load shunt gain value */
if (device_property_read_u32(dev, "ti,shunt-gain", &data->gain) < 0)
data->gain = 4; /* Default of ADCRANGE = 0 */
if (data->gain != 1 && data->gain != 2 && data->gain != 4) {
dev_err(dev, "invalid shunt gain value %u\n", data->gain);
return -EINVAL;
}
/* 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) /* 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);
@ -824,8 +825,9 @@ static int ina238_probe(struct i2c_client *client)
if (IS_ERR(hwmon_dev))
return PTR_ERR(hwmon_dev);
dev_info(dev, "power monitor %s (Rshunt = %u uOhm, gain = %u)\n",
client->name, data->rshunt, data->gain);
if (data->rshunt)
dev_info(dev, "power monitor %s (Rshunt = %u uOhm, gain = %u)\n",
client->name, data->rshunt, data->gain);
return 0;
}