Documentation/hwmon/ina209.rst

   1 Kernel driver ina209
   2 ====================
   3
   4 Supported chips:
   5
   6   * Burr-Brown / Texas Instruments INA209
   7
   8     Prefix: 'ina209'
   9
  10     Addresses scanned: -
  11
  12     Datasheet:
  13         http://www.ti.com/lit/gpn/ina209
  14
  15 Author:
  16         - Paul Hays <Paul.Hays@cattail.ca>
  17         - Ira W. Snyder <iws@ovro.caltech.edu>
  18         - Guenter Roeck <linux@roeck-us.net>
  19
  20
  21 Description
  22 -----------
  23
  24 The TI / Burr-Brown INA209 monitors voltage, current, and power on the high side
  25 of a D.C. power supply. It can perform measurements and calculations in the
  26 background to supply readings at any time. It includes a programmable
  27 calibration multiplier to scale the displayed current and power values.
  28
  29
  30 Sysfs entries
  31 -------------
  32
  33 The INA209 chip is highly configurable both via hardwiring and via
  34 the I2C bus. See the datasheet for details.
  35
  36 This tries to expose most monitoring features of the hardware via
  37 sysfs. It does not support every feature of this chip.
  38
  39 ======================= =======================================================
  40 in0_input               shunt voltage (mV)
  41 in0_input_highest       shunt voltage historical maximum reading (mV)
  42 in0_input_lowest        shunt voltage historical minimum reading (mV)
  43 in0_reset_history       reset shunt voltage history
  44 in0_max                 shunt voltage max alarm limit (mV)
  45 in0_min                 shunt voltage min alarm limit (mV)
  46 in0_crit_max            shunt voltage crit max alarm limit (mV)
  47 in0_crit_min            shunt voltage crit min alarm limit (mV)
  48 in0_max_alarm           shunt voltage max alarm limit exceeded
  49 in0_min_alarm           shunt voltage min alarm limit exceeded
  50 in0_crit_max_alarm      shunt voltage crit max alarm limit exceeded
  51 in0_crit_min_alarm      shunt voltage crit min alarm limit exceeded
  52
  53 in1_input               bus voltage (mV)
  54 in1_input_highest       bus voltage historical maximum reading (mV)
  55 in1_input_lowest        bus voltage historical minimum reading (mV)
  56 in1_reset_history       reset bus voltage history
  57 in1_max                 bus voltage max alarm limit (mV)
  58 in1_min                 bus voltage min alarm limit (mV)
  59 in1_crit_max            bus voltage crit max alarm limit (mV)
  60 in1_crit_min            bus voltage crit min alarm limit (mV)
  61 in1_max_alarm           bus voltage max alarm limit exceeded
  62 in1_min_alarm           bus voltage min alarm limit exceeded
  63 in1_crit_max_alarm      bus voltage crit max alarm limit exceeded
  64 in1_crit_min_alarm      bus voltage crit min alarm limit exceeded
  65
  66 power1_input            power measurement (uW)
  67 power1_input_highest    power historical maximum reading (uW)
  68 power1_reset_history    reset power history
  69 power1_max              power max alarm limit (uW)
  70 power1_crit             power crit alarm limit (uW)
  71 power1_max_alarm        power max alarm limit exceeded
  72 power1_crit_alarm       power crit alarm limit exceeded
  73
  74 curr1_input             current measurement (mA)
  75
  76 update_interval         data conversion time; affects number of samples used
  77                         to average results for shunt and bus voltages.
  78 ======================= =======================================================
  79
  80 General Remarks
  81 ---------------
  82
  83 The power and current registers in this chip require that the calibration
  84 register is programmed correctly before they are used. Normally this is expected
  85 to be done in the BIOS. In the absence of BIOS programming, the shunt resistor
  86 voltage can be provided using platform data. The driver uses platform data from
  87 the ina2xx driver for this purpose. If calibration register data is not provided
  88 via platform data, the driver checks if the calibration register has been
  89 programmed (ie has a value not equal to zero). If so, this value is retained.
  90 Otherwise, a default value reflecting a shunt resistor value of 10 mOhm is
  91 programmed into the calibration register.
  92
  93
  94 Output Pins
  95 -----------
  96
  97 Output pin programming is a board feature which depends on the BIOS. It is
  98 outside the scope of a hardware monitoring driver to enable or disable output
  99 pins.