Kernel driver ina209¶
Supported chips:
Burr-Brown / Texas Instruments INA209
Prefix: ‘ina209’
Addresses scanned: -
- Datasheet:
- Author:
- Paul Hays <Paul.Hays@cattail.ca>
- Ira W. Snyder <iws@ovro.caltech.edu>
- Guenter Roeck <linux@roeck-us.net>
Description¶
The TI / Burr-Brown INA209 monitors voltage, current, and power on the high side of a D.C. power supply. It can perform measurements and calculations in the background to supply readings at any time. It includes a programmable calibration multiplier to scale the displayed current and power values.
Sysfs entries¶
The INA209 chip is highly configurable both via hardwiring and via the I2C bus. See the datasheet for details.
This tries to expose most monitoring features of the hardware via sysfs. It does not support every feature of this chip.
| in0_input | shunt voltage (mV) |
| in0_input_highest | shunt voltage historical maximum reading (mV) |
| in0_input_lowest | shunt voltage historical minimum reading (mV) |
| in0_reset_history | reset shunt voltage history |
| in0_max | shunt voltage max alarm limit (mV) |
| in0_min | shunt voltage min alarm limit (mV) |
| in0_crit_max | shunt voltage crit max alarm limit (mV) |
| in0_crit_min | shunt voltage crit min alarm limit (mV) |
| in0_max_alarm | shunt voltage max alarm limit exceeded |
| in0_min_alarm | shunt voltage min alarm limit exceeded |
| in0_crit_max_alarm | shunt voltage crit max alarm limit exceeded |
| in0_crit_min_alarm | shunt voltage crit min alarm limit exceeded |
| in1_input | bus voltage (mV) |
| in1_input_highest | bus voltage historical maximum reading (mV) |
| in1_input_lowest | bus voltage historical minimum reading (mV) |
| in1_reset_history | reset bus voltage history |
| in1_max | bus voltage max alarm limit (mV) |
| in1_min | bus voltage min alarm limit (mV) |
| in1_crit_max | bus voltage crit max alarm limit (mV) |
| in1_crit_min | bus voltage crit min alarm limit (mV) |
| in1_max_alarm | bus voltage max alarm limit exceeded |
| in1_min_alarm | bus voltage min alarm limit exceeded |
| in1_crit_max_alarm | bus voltage crit max alarm limit exceeded |
| in1_crit_min_alarm | bus voltage crit min alarm limit exceeded |
| power1_input | power measurement (uW) |
| power1_input_highest | power historical maximum reading (uW) |
| power1_reset_history | reset power history |
| power1_max | power max alarm limit (uW) |
| power1_crit | power crit alarm limit (uW) |
| power1_max_alarm | power max alarm limit exceeded |
| power1_crit_alarm | power crit alarm limit exceeded |
| curr1_input | current measurement (mA) |
| update_interval | data conversion time; affects number of samples used to average results for shunt and bus voltages. |
General Remarks¶
The power and current registers in this chip require that the calibration register is programmed correctly before they are used. Normally this is expected to be done in the BIOS. In the absence of BIOS programming, the shunt resistor voltage can be provided using platform data. The driver uses platform data from the ina2xx driver for this purpose. If calibration register data is not provided via platform data, the driver checks if the calibration register has been programmed (ie has a value not equal to zero). If so, this value is retained. Otherwise, a default value reflecting a shunt resistor value of 10 mOhm is programmed into the calibration register.
Output Pins¶
Output pin programming is a board feature which depends on the BIOS. It is outside the scope of a hardware monitoring driver to enable or disable output pins.