mirror of
https://github.com/torvalds/linux.git
synced 2024-12-22 10:56:40 +00:00
be2a608bd0
Convert files within the Documentation directory to UTF-8. Adrian Bunk: small additional fixes Signed-off-by: John Anthony Kazos Jr. <jakj@j-a-k-j.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
79 lines
3.4 KiB
Plaintext
79 lines
3.4 KiB
Plaintext
Kernel driver via686a
|
|
=====================
|
|
|
|
Supported chips:
|
|
* Via VT82C686A, VT82C686B Southbridge Integrated Hardware Monitor
|
|
Prefix: 'via686a'
|
|
Addresses scanned: ISA in PCI-space encoded address
|
|
Datasheet: On request through web form (http://www.via.com.tw/en/support/datasheets/)
|
|
|
|
Authors:
|
|
Kyösti Mälkki <kmalkki@cc.hut.fi>,
|
|
Mark D. Studebaker <mdsxyz123@yahoo.com>
|
|
Bob Dougherty <bobd@stanford.edu>
|
|
(Some conversion-factor data were contributed by
|
|
Jonathan Teh Soon Yew <j.teh@iname.com>
|
|
and Alex van Kaam <darkside@chello.nl>.)
|
|
|
|
Module Parameters
|
|
-----------------
|
|
|
|
force_addr=0xaddr Set the I/O base address. Useful for boards that
|
|
don't set the address in the BIOS. Look for a BIOS
|
|
upgrade before resorting to this. Does not do a
|
|
PCI force; the via686a must still be present in lspci.
|
|
Don't use this unless the driver complains that the
|
|
base address is not set.
|
|
Example: 'modprobe via686a force_addr=0x6000'
|
|
|
|
Description
|
|
-----------
|
|
|
|
The driver does not distinguish between the chips and reports
|
|
all as a 686A.
|
|
|
|
The Via 686a southbridge has integrated hardware monitor functionality.
|
|
It also has an I2C bus, but this driver only supports the hardware monitor.
|
|
For the I2C bus driver, see <file:Documentation/i2c/busses/i2c-viapro>
|
|
|
|
The Via 686a implements three temperature sensors, two fan rotation speed
|
|
sensors, five voltage sensors and alarms.
|
|
|
|
Temperatures are measured in degrees Celsius. An alarm is triggered once
|
|
when the Overtemperature Shutdown limit is crossed; it is triggered again
|
|
as soon as it drops below the hysteresis value.
|
|
|
|
Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
|
|
triggered if the rotation speed has dropped below a programmable limit. Fan
|
|
readings can be divided by a programmable divider (1, 2, 4 or 8) to give
|
|
the readings more range or accuracy. Not all RPM values can accurately be
|
|
represented, so some rounding is done. With a divider of 2, the lowest
|
|
representable value is around 2600 RPM.
|
|
|
|
Voltage sensors (also known as IN sensors) report their values in volts.
|
|
An alarm is triggered if the voltage has crossed a programmable minimum
|
|
or maximum limit. Voltages are internally scalled, so each voltage channel
|
|
has a different resolution and range.
|
|
|
|
If an alarm triggers, it will remain triggered until the hardware register
|
|
is read at least once. This means that the cause for the alarm may
|
|
already have disappeared! Note that in the current implementation, all
|
|
hardware registers are read whenever any data is read (unless it is less
|
|
than 1.5 seconds since the last update). This means that you can easily
|
|
miss once-only alarms.
|
|
|
|
The driver only updates its values each 1.5 seconds; reading it more often
|
|
will do no harm, but will return 'old' values.
|
|
|
|
Known Issues
|
|
------------
|
|
|
|
This driver handles sensors integrated in some VIA south bridges. It is
|
|
possible that a motherboard maker used a VT82C686A/B chip as part of a
|
|
product design but was not interested in its hardware monitoring features,
|
|
in which case the sensor inputs will not be wired. This is the case of
|
|
the Asus K7V, A7V and A7V133 motherboards, to name only a few of them.
|
|
So, if you need the force_addr parameter, and end up with values which
|
|
don't seem to make any sense, don't look any further: your chip is simply
|
|
not wired for hardware monitoring.
|