Documentation/hwmon/f71882fg.rst

   1 Kernel driver f71882fg
   2 ======================
   3
   4 Supported chips:
   5
   6   * Fintek F71808E
   7
   8     Prefix: 'f71808e'
   9
  10     Addresses scanned: none, address read from Super I/O config space
  11
  12     Datasheet: Not public
  13
  14   * Fintek F71808A
  15
  16     Prefix: 'f71808a'
  17
  18     Addresses scanned: none, address read from Super I/O config space
  19
  20     Datasheet: Not public
  21
  22   * Fintek F71858FG
  23
  24     Prefix: 'f71858fg'
  25
  26     Addresses scanned: none, address read from Super I/O config space
  27
  28     Datasheet: Available from the Fintek website
  29
  30   * Fintek F71862FG and F71863FG
  31
  32     Prefix: 'f71862fg'
  33
  34     Addresses scanned: none, address read from Super I/O config space
  35
  36     Datasheet: Available from the Fintek website
  37
  38   * Fintek F71869F and F71869E
  39
  40     Prefix: 'f71869'
  41
  42     Addresses scanned: none, address read from Super I/O config space
  43
  44     Datasheet: Available from the Fintek website
  45
  46   * Fintek F71869A
  47
  48     Prefix: 'f71869a'
  49
  50     Addresses scanned: none, address read from Super I/O config space
  51
  52     Datasheet: Not public
  53
  54   * Fintek F71882FG and F71883FG
  55
  56     Prefix: 'f71882fg'
  57
  58     Addresses scanned: none, address read from Super I/O config space
  59
  60     Datasheet: Available from the Fintek website
  61
  62   * Fintek F71889FG
  63
  64     Prefix: 'f71889fg'
  65
  66     Addresses scanned: none, address read from Super I/O config space
  67
  68     Datasheet: Available from the Fintek website
  69
  70   * Fintek F71889ED
  71
  72     Prefix: 'f71889ed'
  73
  74     Addresses scanned: none, address read from Super I/O config space
  75
  76     Datasheet: Should become available on the Fintek website soon
  77
  78   * Fintek F71889A
  79
  80     Prefix: 'f71889a'
  81
  82     Addresses scanned: none, address read from Super I/O config space
  83
  84     Datasheet: Should become available on the Fintek website soon
  85
  86   * Fintek F8000
  87
  88     Prefix: 'f8000'
  89
  90     Addresses scanned: none, address read from Super I/O config space
  91
  92     Datasheet: Not public
  93
  94   * Fintek F81801U
  95
  96     Prefix: 'f71889fg'
  97
  98     Addresses scanned: none, address read from Super I/O config space
  99
 100     Datasheet: Not public
 101
 102     Note:
 103           This is the 64-pin variant of the F71889FG, they have the
 104           same device ID and are fully compatible as far as hardware
 105           monitoring is concerned.
 106
 107   * Fintek F81865F
 108
 109     Prefix: 'f81865f'
 110
 111     Addresses scanned: none, address read from Super I/O config space
 112
 113     Datasheet: Available from the Fintek website
 114
 115 Author: Hans de Goede <hdegoede@redhat.com>
 116
 117
 118 Description
 119 -----------
 120
 121 Fintek F718xx/F8000 Super I/O chips include complete hardware monitoring
 122 capabilities. They can monitor up to 9 voltages, 4 fans and 3 temperature
 123 sensors.
 124
 125 These chips also have fan controlling features, using either DC or PWM, in
 126 three different modes (one manual, two automatic).
 127
 128 The driver assumes that no more than one chip is present, which seems
 129 reasonable.
 130
 131
 132 Monitoring
 133 ----------
 134
 135 The Voltage, Fan and Temperature Monitoring uses the standard sysfs
 136 interface as documented in sysfs-interface, without any exceptions.
 137
 138
 139 Fan Control
 140 -----------
 141
 142 Both PWM (pulse-width modulation) and DC fan speed control methods are
 143 supported. The right one to use depends on external circuitry on the
 144 motherboard, so the driver assumes that the BIOS set the method
 145 properly.
 146
 147 Note that the lowest numbered temperature zone trip point corresponds to
 148 the border between the highest and one but highest temperature zones, and
 149 vica versa. So the temperature zone trip points 1-4 (or 1-2) go from high temp
 150 to low temp! This is how things are implemented in the IC, and the driver
 151 mimics this.
 152
 153 There are 2 modes to specify the speed of the fan, PWM duty cycle (or DC
 154 voltage) mode, where 0-100% duty cycle (0-100% of 12V) is specified. And RPM
 155 mode where the actual RPM of the fan (as measured) is controlled and the speed
 156 gets specified as 0-100% of the fan#_full_speed file.
 157
 158 Since both modes work in a 0-100% (mapped to 0-255) scale, there isn't a
 159 whole lot of a difference when modifying fan control settings. The only
 160 important difference is that in RPM mode the 0-100% controls the fan speed
 161 between 0-100% of fan#_full_speed. It is assumed that if the BIOS programs
 162 RPM mode, it will also set fan#_full_speed properly, if it does not then
 163 fan control will not work properly, unless you set a sane fan#_full_speed
 164 value yourself.
 165
 166 Switching between these modes requires re-initializing a whole bunch of
 167 registers, so the mode which the BIOS has set is kept. The mode is
 168 printed when loading the driver.
 169
 170 Three different fan control modes are supported; the mode number is written
 171 to the pwm#_enable file. Note that not all modes are supported on all
 172 chips, and some modes may only be available in RPM / PWM mode.
 173 Writing an unsupported mode will result in an invalid parameter error.
 174
 175 * 1: Manual mode
 176   You ask for a specific PWM duty cycle / DC voltage or a specific % of
 177   fan#_full_speed by writing to the pwm# file. This mode is only
 178   available on the F71858FG / F8000 if the fan channel is in RPM mode.
 179
 180 * 2: Normal auto mode
 181   You can define a number of temperature/fan speed trip points, which % the
 182   fan should run at at this temp and which temp a fan should follow using the
 183   standard sysfs interface. The number and type of trip points is chip
 184   depended, see which files are available in sysfs.
 185   Fan/PWM channel 3 of the F8000 is always in this mode!
 186
 187 * 3: Thermostat mode (Only available on the F8000 when in duty cycle mode)
 188   The fan speed is regulated to keep the temp the fan is mapped to between
 189   temp#_auto_point2_temp and temp#_auto_point3_temp.
 190
 191 All of the automatic modes require that pwm1 corresponds to fan1, pwm2 to
 192 fan2 and pwm3 to fan3.