github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-30 01:53:29 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

iio: adc: ina2xx: add INA236 support

Browse Source 
The calibration divisor is not directly specified in the datasheet, but can be calculated:

I = Current_LSB * Current
Current = ShuntVoltage * CAL / calibration_divisor
CAL = 0.00512 / (Current_LSB * Rshunt)
ShuntVoltage = Vshunt / ShuntVoltage_LSB

=> I = (0.00512 / (calibration_divisor*ShuntVoltage_LSB)) * (Vshunt / Rshunt)

Ohm's law, I = Vshunt / Rshunt
=> 0.00512 / (calibration_divisor*ShuntVoltage_LSB) = 1

ShuntVoltage_LSB = 2.5 uV = 0.0000025 V
=> calibration_divisor = 2048

Signed-off-by: Chuang Zhu <git@chuang.cz>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Chuang Zhu 2026-03-16 02:23:04 +08:00 committed by Jonathan Cameron
parent 54dde4b1ed
commit 733bcf18ea
1 changed files with 53 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

65
drivers/iio/adc/ina2xx-adc.c
View File

@ -121,7 +121,7 @@ static const struct regmap_config ina2xx_regmap_config = {
.volatile_reg = ina2xx_is_volatile_reg,
};
enum ina2xx_ids { ina219, ina226 };
enum ina2xx_ids { ina219, ina226, ina236 };
struct ina2xx_config {
const char *name;
@ -175,6 +175,16 @@ static const struct ina2xx_config ina2xx_config[] = {
.power_lsb_factor = 25,
.chip_id = ina226,
},
[ina236] = {
.name = "ina236",
.config_default = INA226_CONFIG_DEFAULT,
.calibration_value = 2048,
.shunt_voltage_lsb = 2500,
.bus_voltage_shift = 0,
.bus_voltage_lsb = 1600,
.power_lsb_factor = 32,
.chip_id = ina236,
},
};
static int ina2xx_read_raw(struct iio_dev *indio_dev,
@ -499,20 +509,26 @@ static int ina2xx_write_raw(struct iio_dev *indio_dev,
break;
case IIO_CHAN_INFO_INT_TIME:
if (chip->config->chip_id == ina226) {
switch (chip->config->chip_id) {
case ina226:
case ina236:
if (chan->address == INA2XX_SHUNT_VOLTAGE)
ret = ina226_set_int_time_vshunt(chip, val2,
&tmp);
else
ret = ina226_set_int_time_vbus(chip, val2,
&tmp);
} else {
break;
case ina219:
if (chan->address == INA2XX_SHUNT_VOLTAGE)
ret = ina219_set_int_time_vshunt(chip, val2,
&tmp);
else
ret = ina219_set_int_time_vbus(chip, val2,
&tmp);
break;
default:
ret = -EINVAL;
}
break;
@ -727,19 +743,27 @@ static int ina2xx_conversion_ready(struct iio_dev *indio_dev)
* For now, we do an extra read of the MASK_ENABLE register (INA226)
* resp. the BUS_VOLTAGE register (INA219).
*/
if (chip->config->chip_id == ina226) {
switch (chip->config->chip_id) {
case ina226:
case ina236:
ret = regmap_read(chip->regmap,
INA226_MASK_ENABLE, &alert);
if (ret < 0)
return ret;
alert &= INA226_CVRF;
} else {
break;
case ina219:
ret = regmap_read(chip->regmap,
INA2XX_BUS_VOLTAGE, &alert);
if (ret < 0)
return ret;
alert &= INA219_CNVR;
break;
default:
return -EINVAL;
}
if (ret < 0)
return ret;
return !!alert;
}
@ -998,16 +1022,22 @@ static int ina2xx_probe(struct i2c_client *client)
/* Patch the current config register with default. */
val = chip->config->config_default;
if (type == ina226) {
switch (type) {
case ina226:
case ina236:
ina226_set_average(chip, INA226_DEFAULT_AVG, &val);
ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val);
ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val);
} else {
break;
case ina219:
chip->avg = 1;
ina219_set_int_time_vbus(chip, INA219_DEFAULT_IT, &val);
ina219_set_int_time_vshunt(chip, INA219_DEFAULT_IT, &val);
ina219_set_vbus_range_denom(chip, INA219_DEFAULT_BRNG, &val);
ina219_set_vshunt_pga_gain(chip, INA219_DEFAULT_PGA, &val);
break;
default:
return -EINVAL;
}
ret = ina2xx_init(chip, val);
@ -1017,14 +1047,20 @@ static int ina2xx_probe(struct i2c_client *client)
}
indio_dev->modes = INDIO_DIRECT_MODE;
if (type == ina226) {
switch (type) {
case ina226:
case ina236:
indio_dev->channels = ina226_channels;
indio_dev->num_channels = ARRAY_SIZE(ina226_channels);
indio_dev->info = &ina226_info;
} else {
break;
case ina219:
indio_dev->channels = ina219_channels;
indio_dev->num_channels = ARRAY_SIZE(ina219_channels);
indio_dev->info = &ina219_info;
break;
default:
return -EINVAL;
}
indio_dev->name = id ? id->name : chip->config->name;
@ -1057,6 +1093,7 @@ static const struct i2c_device_id ina2xx_id[] = {
{ "ina226", ina226 },
{ "ina230", ina226 },
{ "ina231", ina226 },
{ "ina236", ina236 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ina2xx_id);
@ -1082,6 +1119,10 @@ static const struct of_device_id ina2xx_of_match[] = {
.compatible = "ti,ina231",
.data = (void *)ina226
},
{
.compatible = "ti,ina236",
.data = (void *)ina236
},
{ }
};
MODULE_DEVICE_TABLE(of, ina2xx_of_match);