Documentation/hwmon/f71882fg

   1 Kernel driver f71882fg
   2 ======================
   3
   4 Supported chips:
   5   * Fintek F71808E
   6     Prefix: 'f71808e'
   7     Addresses scanned: none, address read from Super I/O config space
   8     Datasheet: Not public
   9   * Fintek F71808A
  10     Prefix: 'f71808a'
  11     Addresses scanned: none, address read from Super I/O config space
  12     Datasheet: Not public
  13   * Fintek F71858FG
  14     Prefix: 'f71858fg'
  15     Addresses scanned: none, address read from Super I/O config space
  16     Datasheet: Available from the Fintek website
  17   * Fintek F71862FG and F71863FG
  18     Prefix: 'f71862fg'
  19     Addresses scanned: none, address read from Super I/O config space
  20     Datasheet: Available from the Fintek website
  21   * Fintek F71869F and F71869E
  22     Prefix: 'f71869'
  23     Addresses scanned: none, address read from Super I/O config space
  24     Datasheet: Available from the Fintek website
  25   * Fintek F71882FG and F71883FG
  26     Prefix: 'f71882fg'
  27     Addresses scanned: none, address read from Super I/O config space
  28     Datasheet: Available from the Fintek website
  29   * Fintek F71889FG
  30     Prefix: 'f71889fg'
  31     Addresses scanned: none, address read from Super I/O config space
  32     Datasheet: Available from the Fintek website
  33   * Fintek F71889ED
  34     Prefix: 'f71889ed'
  35     Addresses scanned: none, address read from Super I/O config space
  36     Datasheet: Should become available on the Fintek website soon
  37   * Fintek F71889A
  38     Prefix: 'f71889a'
  39     Addresses scanned: none, address read from Super I/O config space
  40     Datasheet: Should become available on the Fintek website soon
  41   * Fintek F8000
  42     Prefix: 'f8000'
  43     Addresses scanned: none, address read from Super I/O config space
  44     Datasheet: Not public
  45   * Fintek F81801U
  46     Prefix: 'f71889fg'
  47     Addresses scanned: none, address read from Super I/O config space
  48     Datasheet: Not public
  49     Note: This is the 64-pin variant of the F71889FG, they have the
  50           same device ID and are fully compatible as far as hardware
  51           monitoring is concerned.
  52   * Fintek F81865F
  53     Prefix: 'f81865f'
  54     Addresses scanned: none, address read from Super I/O config space
  55     Datasheet: Available from the Fintek website
  56
  57 Author: Hans de Goede <hdegoede@redhat.com>
  58
  59
  60 Description
  61 -----------
  62
  63 Fintek F718xx/F8000 Super I/O chips include complete hardware monitoring
  64 capabilities. They can monitor up to 9 voltages, 4 fans and 3 temperature
  65 sensors.
  66
  67 These chips also have fan controlling features, using either DC or PWM, in
  68 three different modes (one manual, two automatic).
  69
  70 The driver assumes that no more than one chip is present, which seems
  71 reasonable.
  72
  73
  74 Monitoring
  75 ----------
  76
  77 The Voltage, Fan and Temperature Monitoring uses the standard sysfs
  78 interface as documented in sysfs-interface, without any exceptions.
  79
  80
  81 Fan Control
  82 -----------
  83
  84 Both PWM (pulse-width modulation) and DC fan speed control methods are
  85 supported. The right one to use depends on external circuitry on the
  86 motherboard, so the driver assumes that the BIOS set the method
  87 properly.
  88
  89 Note that the lowest numbered temperature zone trip point corresponds to
  90 to the border between the highest and one but highest temperature zones, and
  91 vica versa. So the temperature zone trip points 1-4 (or 1-2) go from high temp
  92 to low temp! This is how things are implemented in the IC, and the driver
  93 mimicks this.
  94
  95 There are 2 modes to specify the speed of the fan, PWM duty cycle (or DC
  96 voltage) mode, where 0-100% duty cycle (0-100% of 12V) is specified. And RPM
  97 mode where the actual RPM of the fan (as measured) is controlled and the speed
  98 gets specified as 0-100% of the fan#_full_speed file.
  99
 100 Since both modes work in a 0-100% (mapped to 0-255) scale, there isn't a
 101 whole lot of a difference when modifying fan control settings. The only
 102 important difference is that in RPM mode the 0-100% controls the fan speed
 103 between 0-100% of fan#_full_speed. It is assumed that if the BIOS programs
 104 RPM mode, it will also set fan#_full_speed properly, if it does not then
 105 fan control will not work properly, unless you set a sane fan#_full_speed
 106 value yourself.
 107
 108 Switching between these modes requires re-initializing a whole bunch of
 109 registers, so the mode which the BIOS has set is kept. The mode is
 110 printed when loading the driver.
 111
 112 Three different fan control modes are supported; the mode number is written
 113 to the pwm#_enable file. Note that not all modes are supported on all
 114 chips, and some modes may only be available in RPM / PWM mode.
 115 Writing an unsupported mode will result in an invalid parameter error.
 116
 117 * 1: Manual mode
 118   You ask for a specific PWM duty cycle / DC voltage or a specific % of
 119   fan#_full_speed by writing to the pwm# file. This mode is only
 120   available on the F71858FG / F8000 if the fan channel is in RPM mode.
 121
 122 * 2: Normal auto mode
 123   You can define a number of temperature/fan speed trip points, which % the
 124   fan should run at at this temp and which temp a fan should follow using the
 125   standard sysfs interface. The number and type of trip points is chip
 126   depended, see which files are available in sysfs.
 127   Fan/PWM channel 3 of the F8000 is always in this mode!
 128
 129 * 3: Thermostat mode (Only available on the F8000 when in duty cycle mode)
 130   The fan speed is regulated to keep the temp the fan is mapped to between
 131   temp#_auto_point2_temp and temp#_auto_point3_temp.
 132
 133 All of the automatic modes require that pwm1 corresponds to fan1, pwm2 to
 134 fan2 and pwm3 to fan3.