Documentation/hwmon/w83793

   1 Kernel driver w83793
   2 ====================
   3
   4 Supported chips:
   5   * Winbond W83793G/W83793R
   6     Prefix: 'w83793'
   7     Addresses scanned: I2C 0x2c - 0x2f
   8     Datasheet: Still not published
   9
  10 Authors:
  11     Yuan Mu (Winbond Electronics)
  12     Rudolf Marek <r.marek@assembler.cz>
  13
  14
  15 Module parameters
  16 -----------------
  17
  18 * reset int
  19   (default 0)
  20   This parameter is not recommended, it will lose motherboard specific
  21   settings. Use 'reset=1' to reset the chip when loading this module.
  22
  23 * force_subclients=bus,caddr,saddr1,saddr2
  24   This is used to force the i2c addresses for subclients of
  25   a certain chip. Typical usage is `force_subclients=0,0x2f,0x4a,0x4b'
  26   to force the subclients of chip 0x2f on bus 0 to i2c addresses
  27   0x4a and 0x4b.
  28
  29
  30 Description
  31 -----------
  32
  33 This driver implements support for Winbond W83793G/W83793R chips.
  34
  35 * Exported features
  36   This driver exports 10 voltage sensors, up to 12 fan tachometer inputs,
  37   6 remote temperatures, up to 8 sets of PWM fan controls, SmartFan
  38   (automatic fan speed control) on all temperature/PWM combinations, 2
  39   sets of 6-pin CPU VID input.
  40
  41 * Sensor resolutions
  42   If your motherboard maker used the reference design, the resolution of
  43   voltage0-2 is 2mV, resolution of voltage3/4/5 is 16mV, 8mV for voltage6,
  44   24mV for voltage7/8. Temp1-4 have a 0.25 degree Celsius resolution,
  45   temp5-6 have a 1 degree Celsiis resolution.
  46
  47 * Temperature sensor types
  48   Temp1-4 have 2 possible types. It can be read from (and written to)
  49   temp[1-4]_type.
  50   - If the value is 3, it starts monitoring using a remote termal diode
  51     (default).
  52   - If the value is 6, it starts monitoring using the temperature sensor
  53     in Intel CPU and get result by PECI.
  54   Temp5-6 can be connected to external thermistors (value of
  55   temp[5-6]_type is 4).
  56
  57 * Alarm mechanism
  58   For voltage sensors, an alarm triggers if the measured value is below
  59   the low voltage limit or over the high voltage limit.
  60   For temperature sensors, an alarm triggers if the measured value goes
  61   above the high temperature limit, and wears off only after the measured
  62   value drops below the hysteresis value.
  63   For fan sensors, an alarm triggers if the measured value is below the
  64   low speed limit.
  65
  66 * SmartFan/PWM control
  67   If you want to set a pwm fan to manual mode, you just need to make sure it
  68   is not controlled by any temp channel, for example, you want to set fan1
  69   to manual mode, you need to check the value of temp[1-6]_fan_map, make
  70   sure bit 0 is cleared in the 6 values. And then set the pwm1 value to
  71   control the fan.
  72
  73   Each temperature channel can control all the 8 PWM outputs (by setting the
  74   corresponding bit in tempX_fan_map), you can set the temperature channel
  75   mode using temp[1-6]_pwm_enable, 2 is Thermal Cruise mode and 3
  76   is the SmartFanII mode. Temperature channels will try to speed up or
  77   slow down all controlled fans, this means one fan can receive different
  78   PWM value requests from different temperature channels, but the chip
  79   will always pick the safest (max) PWM value for each fan.
  80
  81   In Thermal Cruise mode, the chip attempts to keep the temperature at a
  82   predefined value, within a tolerance margin. So if tempX_input >
  83   thermal_cruiseX + toleranceX, the chip will increase the PWM value,
  84   if tempX_input < thermal_cruiseX - toleranceX, the chip will decrease
  85   the PWM value. If the temperature is within the tolerance range, the PWM
  86   value is left unchanged.
  87
  88   SmartFanII works differently, you have to define up to 7 PWM, temperature
  89   trip points, defining a PWM/temperature curve which the chip will follow.
  90   While not fundamentally different from the Thermal Cruise mode, the
  91   implementation is quite different, giving you a finer-grained control.
  92
  93 * Chassis
  94   If the case open alarm triggers, it will stay in this state unless cleared
  95   by writing 0 to the sysfs file "intrusion0_alarm".
  96
  97 * VID and VRM
  98   The VRM version is detected automatically, don't modify the it unless you
  99   *do* know the cpu VRM version and it's not properly detected.
 100
 101
 102 Notes
 103 -----
 104
 105   Only Fan1-5 and PWM1-3 are guaranteed to always exist, other fan inputs and
 106   PWM outputs may or may not exist depending on the chip pin configuration.