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