1Kernel driver ina2xx 2==================== 3 4Supported chips: 5 6 * Texas Instruments INA219 7 8 9 Prefix: 'ina219' 10 Addresses: I2C 0x40 - 0x4f 11 12 Datasheet: Publicly available at the Texas Instruments website 13 14 https://www.ti.com/ 15 16 * Texas Instruments INA220 17 18 Prefix: 'ina220' 19 20 Addresses: I2C 0x40 - 0x4f 21 22 Datasheet: Publicly available at the Texas Instruments website 23 24 https://www.ti.com/ 25 26 * Texas Instruments INA226 27 28 Prefix: 'ina226' 29 30 Addresses: I2C 0x40 - 0x4f 31 32 Datasheet: Publicly available at the Texas Instruments website 33 34 https://www.ti.com/ 35 36 * Texas Instruments INA230 37 38 Prefix: 'ina230' 39 40 Addresses: I2C 0x40 - 0x4f 41 42 Datasheet: Publicly available at the Texas Instruments website 43 44 https://www.ti.com/ 45 46 * Texas Instruments INA231 47 48 Prefix: 'ina231' 49 50 Addresses: I2C 0x40 - 0x4f 51 52 Datasheet: Publicly available at the Texas Instruments website 53 54 https://www.ti.com/ 55 56Author: Lothar Felten <lothar.felten@gmail.com> 57 58Description 59----------- 60 61The INA219 is a high-side current shunt and power monitor with an I2C 62interface. The INA219 monitors both shunt drop and supply voltage, with 63programmable conversion times and filtering. 64 65The INA220 is a high or low side current shunt and power monitor with an I2C 66interface. The INA220 monitors both shunt drop and supply voltage. 67 68The INA226 is a current shunt and power monitor with an I2C interface. 69The INA226 monitors both a shunt voltage drop and bus supply voltage. 70 71INA230 and INA231 are high or low side current shunt and power monitors 72with an I2C interface. The chips monitor both a shunt voltage drop and 73bus supply voltage. 74 75The shunt value in micro-ohms can be set via platform data or device tree at 76compile-time or via the shunt_resistor attribute in sysfs at run-time. Please 77refer to the Documentation/devicetree/bindings/hwmon/ti,ina2xx.yaml for bindings 78if the device tree is used. 79 80Additionally ina226 supports update_interval attribute as described in 81Documentation/hwmon/sysfs-interface.rst. Internally the interval is the sum of 82bus and shunt voltage conversion times multiplied by the averaging rate. We 83don't touch the conversion times and only modify the number of averages. The 84lower limit of the update_interval is 2 ms, the upper limit is 2253 ms. 85The actual programmed interval may vary from the desired value. 86 87General sysfs entries 88--------------------- 89 90======================= =============================== 91in0_input Shunt voltage(mV) channel 92in1_input Bus voltage(mV) channel 93curr1_input Current(mA) measurement channel 94power1_input Power(uW) measurement channel 95shunt_resistor Shunt resistance(uOhm) channel 96======================= =============================== 97 98Sysfs entries for ina226, ina230 and ina231 only 99------------------------------------------------ 100 101======================= ==================================================== 102in0_lcrit Critical low shunt voltage 103in0_crit Critical high shunt voltage 104in0_lcrit_alarm Shunt voltage critical low alarm 105in0_crit_alarm Shunt voltage critical high alarm 106in1_lcrit Critical low bus voltage 107in1_crit Critical high bus voltage 108in1_lcrit_alarm Bus voltage critical low alarm 109in1_crit_alarm Bus voltage critical high alarm 110power1_crit Critical high power 111power1_crit_alarm Power critical high alarm 112update_interval data conversion time; affects number of samples used 113 to average results for shunt and bus voltages. 114======================= ==================================================== 115 116.. note:: 117 118 - Configure `shunt_resistor` before configure `power1_crit`, because power 119 value is calculated based on `shunt_resistor` set. 120 - Because of the underlying register implementation, only one `*crit` setting 121 and its `alarm` can be active. Writing to one `*crit` setting clears other 122 `*crit` settings and alarms. Writing 0 to any `*crit` setting clears all 123 `*crit` settings and alarms. 124