linux/Documentation/hwmon/max31785.rst
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   1Kernel driver max31785
   2======================
   3
   4Supported chips:
   5
   6  * Maxim MAX31785, MAX31785A
   7
   8    Prefix: 'max31785' or 'max31785a'
   9
  10    Addresses scanned: -
  11
  12    Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX31785.pdf
  13
  14Author: Andrew Jeffery <andrew@aj.id.au>
  15
  16Description
  17-----------
  18
  19The Maxim MAX31785 is a PMBus device providing closed-loop, multi-channel fan
  20management with temperature and remote voltage sensing. Various fan control
  21features are provided, including PWM frequency control, temperature hysteresis,
  22dual tachometer measurements, and fan health monitoring.
  23
  24For dual-rotor configurations the MAX31785A exposes the second rotor tachometer
  25readings in attributes fan[5-8]_input. By contrast the MAX31785 only exposes
  26the slowest rotor measurement, and does so in the fan[1-4]_input attributes.
  27
  28Usage Notes
  29-----------
  30
  31This driver does not probe for PMBus devices. You will have to instantiate
  32devices explicitly.
  33
  34Sysfs attributes
  35----------------
  36
  37======================= =======================================================
  38fan[1-4]_alarm          Fan alarm.
  39fan[1-4]_fault          Fan fault.
  40fan[1-8]_input          Fan RPM. On the MAX31785A, inputs 5-8 correspond to the
  41                        second rotor of fans 1-4
  42fan[1-4]_target         Fan input target
  43
  44in[1-6]_crit            Critical maximum output voltage
  45in[1-6]_crit_alarm      Output voltage critical high alarm
  46in[1-6]_input           Measured output voltage
  47in[1-6]_label           "vout[18-23]"
  48in[1-6]_lcrit           Critical minimum output voltage
  49in[1-6]_lcrit_alarm     Output voltage critical low alarm
  50in[1-6]_max             Maximum output voltage
  51in[1-6]_max_alarm       Output voltage high alarm
  52in[1-6]_min             Minimum output voltage
  53in[1-6]_min_alarm       Output voltage low alarm
  54
  55pwm[1-4]                Fan target duty cycle (0..255)
  56pwm[1-4]_enable         0: Full-speed
  57                        1: Manual PWM control
  58                        2: Automatic PWM (tach-feedback RPM fan-control)
  59                        3: Automatic closed-loop (temp-feedback fan-control)
  60
  61temp[1-11]_crit         Critical high temperature
  62temp[1-11]_crit_alarm   Chip temperature critical high alarm
  63temp[1-11]_input        Measured temperature
  64temp[1-11]_max          Maximum temperature
  65temp[1-11]_max_alarm    Chip temperature high alarm
  66======================= =======================================================
  67