Kernel driver ina3221

Supported chips:

  • Texas Instruments INA3221

    Prefix: ‘ina3221’

    Addresses: I2C 0x40 - 0x43

    Datasheet: Publicly available at the Texas Instruments website

Author: Andrew F. Davis <afd@ti.com>

Description

The Texas Instruments INA3221 monitors voltage, current, and power on the high side of up to three D.C. power supplies. The INA3221 monitors both shunt drop and supply voltage, with programmable conversion times and averaging, current and power are calculated host-side from these.

Sysfs entries

in[123]_label

Voltage channel labels

in[123]_enable

Voltage channel enable controls

in[123]_input

Bus voltage(mV) channels

curr[123]_input

Current(mA) measurement channels

shunt[123]_resistor

Shunt resistance(uOhm) channels

curr[123]_crit

Critical alert current(mA) setting, activates the corresponding alarm when the respective current is above this value

curr[123]_crit_alarm

Critical alert current limit exceeded

curr[123]_max

Warning alert current(mA) setting, activates the corresponding alarm when the respective current average is above this value.

curr[123]_max_alarm

Warning alert current limit exceeded

in[456]_input

Shunt voltage(uV) for channels 1, 2, and 3 respectively

in7_input

Sum of shunt voltage(uV) channels

in7_label

Channel label for sum of shunt voltage

curr4_input

Sum of current(mA) measurement channels, (only available when all channels use the same resistor value for their shunt resistors)

curr4_crit

Critical alert current(mA) setting for sum of current measurements, activates the corresponding alarm when the respective current is above this value (only effective when all channels use the same resistor value for their shunt resistors)

curr4_crit_alarm

Critical alert current limit exceeded for sum of current measurements.

samples

Number of samples using in the averaging mode.

Supports the list of number of samples:

1, 4, 16, 64, 128, 256, 512, 1024

update_interval

Data conversion time in millisecond, following:

update_interval = C x S x (BC + SC)

  • C: number of enabled channels

  • S: number of samples

  • BC: bus-voltage conversion time in millisecond

  • SC: shunt-voltage conversion time in millisecond

Affects both Bus- and Shunt-voltage conversion time. Note that setting update_interval to 0ms sets both BC and SC to 140 us (minimum conversion time).