Documentation/hwmon/ltc2947.rst

   1 Kernel drivers ltc2947-i2c and ltc2947-spi
   2 ==========================================
   3
   4 Supported chips:
   5
   6   * Analog Devices LTC2947
   7
   8     Prefix: 'ltc2947'
   9
  10     Addresses scanned: -
  11
  12     Datasheet:
  13
  14         https://www.analog.com/media/en/technical-documentation/data-sheets/LTC2947.pdf
  15
  16 Author: Nuno Sá <nuno.sa@analog.com>
  17
  18 Description
  19 ___________
  20
  21 The LTC2947 is a high precision power and energy monitor that measures current,
  22 voltage, power, temperature, charge and energy. The device supports both SPI
  23 and I2C depending on the chip configuration.
  24 The device also measures accumulated quantities as energy. It has two banks of
  25 register's to read/set energy related values. These banks can be configured
  26 independently to have setups like: energy1 accumulates always and enrgy2 only
  27 accumulates if current is positive (to check battery charging efficiency for
  28 example). The device also supports a GPIO pin that can be configured as output
  29 to control a fan as a function of measured temperature. Then, the GPIO becomes
  30 active as soon as a temperature reading is higher than a defined threshold. The
  31 temp2 channel is used to control this thresholds and to read the respective
  32 alarms.
  33
  34 Sysfs entries
  35 _____________
  36
  37 The following attributes are supported. Limits are read-write, reset_history
  38 is write-only and all the other attributes are read-only.
  39
  40 ======================= ==========================================
  41 in0_input               VP-VM voltage (mV).
  42 in0_min                 Undervoltage threshold
  43 in0_max                 Overvoltage threshold
  44 in0_lowest              Lowest measured voltage
  45 in0_highest             Highest measured voltage
  46 in0_reset_history       Write 1 to reset in1 history
  47 in0_min_alarm           Undervoltage alarm
  48 in0_max_alarm           Overvoltage alarm
  49 in0_label               Channel label (VP-VM)
  50
  51 in1_input               DVCC voltage (mV)
  52 in1_min                 Undervoltage threshold
  53 in1_max                 Overvoltage threshold
  54 in1_lowest              Lowest measured voltage
  55 in1_highest             Highest measured voltage
  56 in1_reset_history       Write 1 to reset in2 history
  57 in1_min_alarm           Undervoltage alarm
  58 in1_max_alarm           Overvoltage alarm
  59 in1_label               Channel label (DVCC)
  60
  61 curr1_input             IP-IM Sense current (mA)
  62 curr1_min               Undercurrent threshold
  63 curr1_max               Overcurrent threshold
  64 curr1_lowest            Lowest measured current
  65 curr1_highest           Highest measured current
  66 curr1_reset_history     Write 1 to reset curr1 history
  67 curr1_min_alarm         Undercurrent alarm
  68 curr1_max_alarm         Overcurrent alarm
  69 curr1_label             Channel label (IP-IM)
  70
  71 power1_input            Power (in uW)
  72 power1_min              Low power threshold
  73 power1_max              High power threshold
  74 power1_input_lowest     Historical minimum power use
  75 power1_input_highest    Historical maximum power use
  76 power1_reset_history    Write 1 to reset power1 history
  77 power1_min_alarm        Low power alarm
  78 power1_max_alarm        High power alarm
  79 power1_label            Channel label (Power)
  80
  81 temp1_input             Chip Temperature (in milliC)
  82 temp1_min               Low temperature threshold
  83 temp1_max               High temperature threshold
  84 temp1_input_lowest      Historical minimum temperature use
  85 temp1_input_highest     Historical maximum temperature use
  86 temp1_reset_history     Write 1 to reset temp1 history
  87 temp1_min_alarm         Low temperature alarm
  88 temp1_max_alarm         High temperature alarm
  89 temp1_label             Channel label (Ambient)
  90
  91 temp2_min               Low temperature threshold for fan control
  92 temp2_max               High temperature threshold for fan control
  93 temp2_min_alarm         Low temperature fan control alarm
  94 temp2_max_alarm         High temperature fan control alarm
  95 temp2_label             Channel label (TEMPFAN)
  96
  97 energy1_input           Measured energy over time (in microJoule)
  98
  99 energy2_input           Measured energy over time (in microJoule)
 100 ======================= ==========================================