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ca8fd8c16a
A user complained that the ftsteutates driver was displaying
bogus values since its introduction. This happens because the
sensor measurements need to be scaled in order to produce
meaningful results:
- the fan speed needs to be multiplied by 60 since its in RPS
- the temperature is in degrees celsius and needs an offset of 64
- the voltage is in 1/256 of 3.3V
The offical datasheet says the voltage needs to be divided by 256,
but this is likely an off-by-one-error, since even the BIOS
devides by 255 (otherwise 3.3V could not be measured).
The voltage channels additionally need a board-specific multiplier,
however this can be done by the driver since its board-specific.
The reason the missing scaling of measurements is the way Fujitsu
used this driver when it was still out-of-tree. Back then, all
scaling was done in userspace by libsensors, even the generic one.
Tested on a Fujitsu DS3401-B1.
Fixes: 08426eda58 ("hwmon: Add driver for FTS BMC chip "Teutates"")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20221224041855.83981-2-W_Armin@gmx.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
38 lines
1.2 KiB
ReStructuredText
38 lines
1.2 KiB
ReStructuredText
Kernel driver ftsteutates
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=========================
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Supported chips:
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* FTS Teutates
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Prefix: 'ftsteutates'
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Addresses scanned: I2C 0x73 (7-Bit)
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Author: Thilo Cestonaro <thilo.cestonaro@ts.fujitsu.com>
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Description
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-----------
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The BMC Teutates is the Eleventh generation of Superior System
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monitoring and thermal management solution. It is builds on the basic
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functionality of the BMC Theseus and contains several new features and
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enhancements. It can monitor up to 4 voltages, 16 temperatures and
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8 fans. It also contains an integrated watchdog which is currently
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implemented in this driver.
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The 4 voltages require a board-specific multiplier, since the BMC can
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only measure voltages up to 3.3V and thus relies on voltage dividers.
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Consult your motherboard manual for details.
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To clear a temperature or fan alarm, execute the following command with the
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correct path to the alarm file::
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echo 0 >XXXX_alarm
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Specification of the chip can be found here:
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- ftp://ftp.ts.fujitsu.com/pub/Mainboard-OEM-Sales/Services/Software&Tools/Linux_SystemMonitoring&Watchdog&GPIO/BMC-Teutates_Specification_V1.21.pdf
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- ftp://ftp.ts.fujitsu.com/pub/Mainboard-OEM-Sales/Services/Software&Tools/Linux_SystemMonitoring&Watchdog&GPIO/Fujitsu_mainboards-1-Sensors_HowTo-en-US.pdf
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