Kernel driver ina2xx¶
Supported chips:
Texas Instruments INA219
Prefix: ‘ina219’ Addresses: I2C 0x40 - 0x4f
Datasheet: Publicly available at the Texas Instruments website
Texas Instruments INA220
Prefix: ‘ina220’
Addresses: I2C 0x40 - 0x4f
Datasheet: Publicly available at the Texas Instruments website
Texas Instruments INA226
Prefix: ‘ina226’
Addresses: I2C 0x40 - 0x4f
Datasheet: Publicly available at the Texas Instruments website
Texas Instruments INA230
Prefix: ‘ina230’
Addresses: I2C 0x40 - 0x4f
Datasheet: Publicly available at the Texas Instruments website
Texas Instruments INA231
Prefix: ‘ina231’
Addresses: I2C 0x40 - 0x4f
Datasheet: Publicly available at the Texas Instruments website
Author: Lothar Felten <lothar.felten@gmail.com>
Description¶
The INA219 is a high-side current shunt and power monitor with an I2C interface. The INA219 monitors both shunt drop and supply voltage, with programmable conversion times and filtering.
The INA220 is a high or low side current shunt and power monitor with an I2C interface. The INA220 monitors both shunt drop and supply voltage.
The INA226 is a current shunt and power monitor with an I2C interface. The INA226 monitors both a shunt voltage drop and bus supply voltage.
INA230 and INA231 are high or low side current shunt and power monitors with an I2C interface. The chips monitor both a shunt voltage drop and bus supply voltage.
The shunt value in micro-ohms can be set via platform data or device tree at compile-time or via the shunt_resistor attribute in sysfs at run-time. Please refer to the Documentation/devicetree/bindings/hwmon/ina2xx.txt for bindings if the device tree is used.
Additionally ina226 supports update_interval attribute as described in Documentation/hwmon/sysfs-interface.rst. Internally the interval is the sum of bus and shunt voltage conversion times multiplied by the averaging rate. We don’t touch the conversion times and only modify the number of averages. The lower limit of the update_interval is 2 ms, the upper limit is 2253 ms. The actual programmed interval may vary from the desired value.
General sysfs entries¶
| in0_input | Shunt voltage(mV) channel |
| in1_input | Bus voltage(mV) channel |
| curr1_input | Current(mA) measurement channel |
| power1_input | Power(uW) measurement channel |
| shunt_resistor | Shunt resistance(uOhm) channel |
Sysfs entries for ina226, ina230 and ina231 only¶
| update_interval | data conversion time; affects number of samples used to average results for shunt and bus voltages. |