1 Kernel driver ina2xx 2 ==================== 3 4 Supported 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 56 Author: Lothar Felten <lothar.felten@gmail.com> 57 58 Description 59 ----------- 60 61 The INA219 is a high-side current shunt and power monitor with an I2C 62 interface. The INA219 monitors both shunt drop and supply voltage, with 63 programmable conversion times and filtering. 64 65 The INA220 is a high or low side current shunt and power monitor with an I2C 66 interface. The INA220 monitors both shunt drop and supply voltage. 67 68 The INA226 is a current shunt and power monitor with an I2C interface. 69 The INA226 monitors both a shunt voltage drop and bus supply voltage. 70 71 INA230 and INA231 are high or low side current shunt and power monitors 72 with an I2C interface. The chips monitor both a shunt voltage drop and 73 bus supply voltage. 74 75 The shunt value in micro-ohms can be set via platform data or device tree at 76 compile-time or via the shunt_resistor attribute in sysfs at run-time. Please 77 refer to the Documentation/devicetree/bindings/hwmon/ti,ina2xx.yaml for bindings 78 if the device tree is used. 79 80 Additionally ina226 supports update_interval attribute as described in 81 Documentation/hwmon/sysfs-interface.rst. Internally the interval is the sum of 82 bus and shunt voltage conversion times multiplied by the averaging rate. We 83 don't touch the conversion times and only modify the number of averages. The 84 lower limit of the update_interval is 2 ms, the upper limit is 2253 ms. 85 The actual programmed interval may vary from the desired value. 86 87 General sysfs entries 88 --------------------- 89 90 ======================= =============================== 91 in0_input Shunt voltage(mV) channel 92 in1_input Bus voltage(mV) channel 93 curr1_input Current(mA) measurement channel 94 power1_input Power(uW) measurement channel 95 shunt_resistor Shunt resistance(uOhm) channel 96 ======================= =============================== 97 98 Sysfs entries for ina226, ina230 and ina231 only 99 ------------------------------------------------ 100 101 ======================= ==================================================== 102 curr1_lcrit Critical low current 103 curr1_crit Critical high current 104 curr1_lcrit_alarm Current critical low alarm 105 curr1_crit_alarm Current critical high alarm 106 in0_lcrit Critical low shunt voltage 107 in0_crit Critical high shunt voltage 108 in0_lcrit_alarm Shunt voltage critical low alarm 109 in0_crit_alarm Shunt voltage critical high alarm 110 in1_lcrit Critical low bus voltage 111 in1_crit Critical high bus voltage 112 in1_lcrit_alarm Bus voltage critical low alarm 113 in1_crit_alarm Bus voltage critical high alarm 114 power1_crit Critical high power 115 power1_crit_alarm Power critical high alarm 116 update_interval data conversion time; affects number of samples used 117 to average results for shunt and bus voltages. 118 ======================= ==================================================== 119 120 .. note:: 121 122 - Configure `shunt_resistor` before configure `power1_crit`, because power 123 value is calculated based on `shunt_resistor` set. 124 - Because of the underlying register implementation, only one `*crit` setting 125 and its `alarm` can be active. Writing to one `*crit` setting clears other 126 `*crit` settings and alarms. Writing 0 to any `*crit` setting clears all 127 `*crit` settings and alarms.
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.