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https://github.com/lm-sensors/lm-sensors.git
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Mark D. Studebaker
8c8d844005
git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@1411 7894878c-1315-0410-8ee3-d5d059ff63e0
58 lines
2.1 KiB
Plaintext
58 lines
2.1 KiB
Plaintext
Kernel driver `smsc74m1.o'
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=========================
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Status: Beta.
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Supported chips:
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* SMSC 74M1xx Super I/O Controllers
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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.smsc.com/main/datasheets/47m10x.pdf
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http://www.smsc.com/main/datasheets/47m120.pdf
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http://www.smsc.com/main/datasheets/47m13x.pdf
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http://www.smsc.com/main/datasheets/47m14x.pdf
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Authors: Mark D. Studebaker <mdsxyz123@yahoo.com>
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With assistance from Bruce Allen <ballen@uwm.edu> and his
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fan.c program: http://www.lsc-group.phys.uwm.edu/%7Eballen/driver/
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Module Parameters
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-----------------
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force_addr=0xaddr Set the I/O base address. Useful for boards
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that don't set the address in the BIOS.
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Don't use this unless the driver complains that the
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base address is not set.
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Example: 'modprobe smsc47m1 force_addr=0x680'
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Description
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-----------
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The Standard Microsystems Corporation (SMSC) 47M1xx Super I/O chips
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contain monitoring and PWM control circuitry for two fans.
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FAN rotation speeds are reported in RPM (rotations per minute). An alarm is
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triggered if the rotation speed has dropped below a programmable limit. FAN
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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. This is important because some FANs
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report only one 'tick' each rotation, while others report two - making
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all readings twice as high. Not all RPM values can accurately be represented,
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so some rounding is done. With a divider of 2, the lowest representable
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value is around 2600 RPM.
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PWM values are from 0 to 100%. The first value in the /proc entry is
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the percentage; the second is the enable (0 or 1).
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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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**********************
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The lm_sensors project gratefully acknowledges the support of
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Intel in the development of this driver.
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