mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-15 19:56:43 +07:00
3b02d332b6
Add some documentation about the f71882fg driver, and update the Kconfig documentation to report the new supported models. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
90 lines
3.4 KiB
Plaintext
90 lines
3.4 KiB
Plaintext
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.
|