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authorJean Delvare <khali@linux-fr.org>2005-07-02 18:52:48 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2005-07-11 23:47:41 +0200
commitede7fbdf526c314850c9f32dd8da1753bf8d0ad5 (patch)
tree2f1fefa6f6df58f5c27bf98bd7df0908e97e44ef /Documentation/hwmon/via686a
parent[PATCH] I2C: Move hwmon drivers (2/3) (diff)
downloadlinux-ede7fbdf526c314850c9f32dd8da1753bf8d0ad5.tar.xz
linux-ede7fbdf526c314850c9f32dd8da1753bf8d0ad5.zip
[PATCH] I2C: Move hwmon drivers (3/3)
Part 3: Move the drivers documentation, plus two general documentation files. Note that the patch "adds trailing whitespace", because it does move the files as-is, and some files happen to have trailing whitespace. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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+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 Asus A7V boards
+ that don't set the address in the BIOS. 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.