| Kernel driver ina2xx |
| ==================== |
| |
| Supported chips: |
| |
| * Texas Instruments INA219 |
| |
| |
| Prefix: 'ina219' |
| Addresses: I2C 0x40 - 0x4f |
| |
| Datasheet: Publicly available at the Texas Instruments website |
| |
| https://www.ti.com/ |
| |
| * Texas Instruments INA220 |
| |
| Prefix: 'ina220' |
| |
| Addresses: I2C 0x40 - 0x4f |
| |
| Datasheet: Publicly available at the Texas Instruments website |
| |
| https://www.ti.com/ |
| |
| * Texas Instruments INA226 |
| |
| Prefix: 'ina226' |
| |
| Addresses: I2C 0x40 - 0x4f |
| |
| Datasheet: Publicly available at the Texas Instruments website |
| |
| https://www.ti.com/ |
| |
| * Texas Instruments INA230 |
| |
| Prefix: 'ina230' |
| |
| Addresses: I2C 0x40 - 0x4f |
| |
| Datasheet: Publicly available at the Texas Instruments website |
| |
| https://www.ti.com/ |
| |
| * Texas Instruments INA231 |
| |
| Prefix: 'ina231' |
| |
| Addresses: I2C 0x40 - 0x4f |
| |
| Datasheet: Publicly available at the Texas Instruments website |
| |
| https://www.ti.com/ |
| |
| 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/ti,ina2xx.yaml 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 |
| ------------------------------------------------ |
| |
| ======================= ==================================================== |
| curr1_lcrit Critical low current |
| curr1_crit Critical high current |
| curr1_lcrit_alarm Current critical low alarm |
| curr1_crit_alarm Current critical high alarm |
| in0_lcrit Critical low shunt voltage |
| in0_crit Critical high shunt voltage |
| in0_lcrit_alarm Shunt voltage critical low alarm |
| in0_crit_alarm Shunt voltage critical high alarm |
| in1_lcrit Critical low bus voltage |
| in1_crit Critical high bus voltage |
| in1_lcrit_alarm Bus voltage critical low alarm |
| in1_crit_alarm Bus voltage critical high alarm |
| power1_crit Critical high power |
| power1_crit_alarm Power critical high alarm |
| update_interval data conversion time; affects number of samples used |
| to average results for shunt and bus voltages. |
| ======================= ==================================================== |
| |
| .. note:: |
| |
| - Configure `shunt_resistor` before configure `power1_crit`, because power |
| value is calculated based on `shunt_resistor` set. |
| - Because of the underlying register implementation, only one `*crit` setting |
| and its `alarm` can be active. Writing to one `*crit` setting clears other |
| `*crit` settings and alarms. Writing 0 to any `*crit` setting clears all |
| `*crit` settings and alarms. |
