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https://github.com/lm-sensors/lm-sensors.git
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Jean Delvare
26d763bb48
and PC87364 fan monitor and controller support. git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@2418 7894878c-1315-0410-8ee3-d5d059ff63e0
57 lines
1.9 KiB
Plaintext
57 lines
1.9 KiB
Plaintext
Kernel driver `pc87360-fan.o'
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=============================
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Status: Alpha, untested.
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Supported chips:
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* National Semiconductor PC87360, PC87363 and PC87364
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Addresses scanned: none, address read from Super I/O config space
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Datasheets:
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http://www.national.com/pf/PC/PC87360.html
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http://www.national.com/pf/PC/PC87363.html
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http://www.national.com/pf/PC/PC87364.html
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Authors: Jean Delvare <khali@linux-fr.org>
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Module Parameters
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-----------------
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None.
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Description
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-----------
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The National Semiconductor PC87360 Super I/O chip contains monitoring and
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PWM control circuitry for two fans. The PC87363 chip is similar, and the
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PC87364 chip has monitoring and PWM control for a third fan.
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Fan rotation speeds are reported in RPM (revolutions per minute). An alarm
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is triggered if the rotation speed has dropped below a programmable limit.
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Fan readings can be divided by a programmable divider (1, 2, 4 or 8) to give
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the readings more range or accuracy. Not all RPM values can accurately be
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represented, so some rounding is done. With a divider of 2, the lowest
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representable value is around 2600 RPM.
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A different alarm is also triggered if the fan speed is too low to be
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measured. It is suggested to increase the fan divisor in this case.
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PWM values are from 0 to 255.
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If an alarm triggers, it will remain triggered until the hardware register
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is read at least once. This means that the cause for the alarm may
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already have disappeared! Note that in the current implementation, all
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hardware registers are read whenever any data is read (unless it is less
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than 1.5 seconds since the last update). This means that you can easily
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miss once-only alarms.
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Limitations
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-----------
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This driver is read-only at the moment. Since I don't own a supported
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chip for testing, and the datasheet suggests that you shouldn't change
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values once the monitoring has started (this is normally done by the BIOS
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at boot time), I decided to play it safe.
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