Documentation/hwmon/ltc2945.rst

   1 Kernel driver ltc2945
   2 =====================
   3
   4 Supported chips:
   5
   6   * Linear Technology LTC2945
   7
   8     Prefix: 'ltc2945'
   9
  10     Addresses scanned: -
  11
  12     Datasheet:
  13
  14         https://www.analog.com/media/en/technical-documentation/data-sheets/2945fb.pdf
  15
  16 Author: Guenter Roeck <linux@roeck-us.net>
  17
  18
  19 Description
  20 -----------
  21
  22 The LTC2945  is a rail-to-rail system monitor that measures current, voltage,
  23 and power consumption.
  24
  25
  26 Usage Notes
  27 -----------
  28
  29 This driver does not probe for LTC2945 devices, since there is no register
  30 which can be safely used to identify the chip. You will have to instantiate
  31 the devices explicitly.
  32
  33 Example: the following will load the driver for an LTC2945 at address 0x10
  34 on I2C bus #1::
  35
  36         $ modprobe ltc2945
  37         $ echo ltc2945 0x10 > /sys/bus/i2c/devices/i2c-1/new_device
  38
  39
  40 Sysfs entries
  41 -------------
  42
  43 Voltage readings provided by this driver are reported as obtained from the ADC
  44 registers. If a set of voltage divider resistors is installed, calculate the
  45 real voltage by multiplying the reported value with (R1+R2)/R2, where R1 is the
  46 value of the divider resistor against the measured voltage and R2 is the value
  47 of the divider resistor against Ground.
  48
  49 Current reading provided by this driver is reported as obtained from the ADC
  50 Current Sense register. The reported value assumes that a 1 mOhm sense resistor
  51 is installed. If a different sense resistor is installed, calculate the real
  52 current by dividing the reported value by the sense resistor value in mOhm.
  53
  54 ======================= ========================================================
  55 in1_input               VIN voltage (mV). Voltage is measured either at
  56                         SENSE+ or VDD pin depending on chip configuration.
  57 in1_min                 Undervoltage threshold
  58 in1_max                 Overvoltage threshold
  59 in1_lowest              Lowest measured voltage
  60 in1_highest             Highest measured voltage
  61 in1_reset_history       Write 1 to reset in1 history
  62 in1_min_alarm           Undervoltage alarm
  63 in1_max_alarm           Overvoltage alarm
  64
  65 in2_input               ADIN voltage (mV)
  66 in2_min                 Undervoltage threshold
  67 in2_max                 Overvoltage threshold
  68 in2_lowest              Lowest measured voltage
  69 in2_highest             Highest measured voltage
  70 in2_reset_history       Write 1 to reset in2 history
  71 in2_min_alarm           Undervoltage alarm
  72 in2_max_alarm           Overvoltage alarm
  73
  74 curr1_input             SENSE current (mA)
  75 curr1_min               Undercurrent threshold
  76 curr1_max               Overcurrent threshold
  77 curr1_lowest            Lowest measured current
  78 curr1_highest           Highest measured current
  79 curr1_reset_history     Write 1 to reset curr1 history
  80 curr1_min_alarm         Undercurrent alarm
  81 curr1_max_alarm         Overcurrent alarm
  82
  83 power1_input            Power (in uW). Power is calculated based on SENSE+/VDD
  84                         voltage or ADIN voltage depending on chip configuration.
  85 power1_min              Low lower threshold
  86 power1_max              High power threshold
  87 power1_input_lowest     Historical minimum power use
  88 power1_input_highest    Historical maximum power use
  89 power1_reset_history    Write 1 to reset power1 history
  90 power1_min_alarm        Low power alarm
  91 power1_max_alarm        High power alarm
  92 ======================= ========================================================