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diff --git a/Documentation/hwmon/f71882fg b/Documentation/hwmon/f71882fg new file mode 100644 index 000000000000..a8321267b5b6 --- /dev/null +++ b/Documentation/hwmon/f71882fg @@ -0,0 +1,89 @@ +Kernel driver f71882fg +====================== + +Supported chips: + * Fintek F71882FG and F71883FG + Prefix: 'f71882fg' + Addresses scanned: none, address read from Super I/O config space + Datasheet: Available from the Fintek website + * Fintek F71862FG and F71863FG + Prefix: 'f71862fg' + Addresses scanned: none, address read from Super I/O config space + Datasheet: Available from the Fintek website + * Fintek F8000 + Prefix: 'f8000' + Addresses scanned: none, address read from Super I/O config space + Datasheet: Not public + +Author: Hans de Goede <hdegoede@redhat.com> + + +Description +----------- + +Fintek F718xxFG/F8000 Super I/O chips include complete hardware monitoring +capabilities. They can monitor up to 9 voltages (3 for the F8000), 4 fans and +3 temperature sensors. + +These chips also have fan controlling features, using either DC or PWM, in +three different modes (one manual, two automatic). + +The driver assumes that no more than one chip is present, which seems +reasonable. + + +Monitoring +---------- + +The Voltage, Fan and Temperature Monitoring uses the standard sysfs +interface as documented in sysfs-interface, without any exceptions. + + +Fan Control +----------- + +Both PWM (pulse-width modulation) and DC fan speed control methods are +supported. The right one to use depends on external circuitry on the +motherboard, so the driver assumes that the BIOS set the method +properly. + +There are 2 modes to specify the speed of the fan, PWM duty cycle (or DC +voltage) mode, where 0-100% duty cycle (0-100% of 12V) is specified. And RPM +mode where the actual RPM of the fan (as measured) is controlled and the speed +gets specified as 0-100% of the fan#_full_speed file. + +Since both modes work in a 0-100% (mapped to 0-255) scale, there isn't a +whole lot of a difference when modifying fan control settings. The only +important difference is that in RPM mode the 0-100% controls the fan speed +between 0-100% of fan#_full_speed. It is assumed that if the BIOS programs +RPM mode, it will also set fan#_full_speed properly, if it does not then +fan control will not work properly, unless you set a sane fan#_full_speed +value yourself. + +Switching between these modes requires re-initializing a whole bunch of +registers, so the mode which the BIOS has set is kept. The mode is +printed when loading the driver. + +Three different fan control modes are supported; the mode number is written +to the pwm#_enable file. Note that not all modes are supported on all +chips, and some modes may only be available in RPM / PWM mode on the F8000. +Writing an unsupported mode will result in an invalid parameter error. + +* 1: Manual mode + You ask for a specific PWM duty cycle / DC voltage or a specific % of + fan#_full_speed by writing to the pwm# file. This mode is only + available on the F8000 if the fan channel is in RPM mode. + +* 2: Normal auto mode + You can define a number of temperature/fan speed trip points, which % the + fan should run at at this temp and which temp a fan should follow using the + standard sysfs interface. The number and type of trip points is chip + depended, see which files are available in sysfs. + Fan/PWM channel 3 of the F8000 is always in this mode! + +* 3: Thermostat mode (Only available on the F8000 when in duty cycle mode) + The fan speed is regulated to keep the temp the fan is mapped to between + temp#_auto_point2_temp and temp#_auto_point3_temp. + +Both of the automatic modes require that pwm1 corresponds to fan1, pwm2 to +fan2 and pwm3 to fan3. |