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Diffstat (limited to 'Documentation/i2c/chips/smsc47m1')
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diff --git a/Documentation/i2c/chips/smsc47m1 b/Documentation/i2c/chips/smsc47m1 new file mode 100644 index 000000000000..34e6478c1425 --- /dev/null +++ b/Documentation/i2c/chips/smsc47m1 @@ -0,0 +1,52 @@ +Kernel driver smsc47m1 +====================== + +Supported chips: + * SMSC LPC47B27x, LPC47M10x, LPC47M13x, LPC47M14x, LPC47M15x and LPC47M192 + Addresses scanned: none, address read from Super I/O config space + Prefix: 'smsc47m1' + Datasheets: + http://www.smsc.com/main/datasheets/47b27x.pdf + http://www.smsc.com/main/datasheets/47m10x.pdf + http://www.smsc.com/main/tools/discontinued/47m13x.pdf + http://www.smsc.com/main/datasheets/47m14x.pdf + http://www.smsc.com/main/tools/discontinued/47m15x.pdf + http://www.smsc.com/main/datasheets/47m192.pdf + +Authors: + Mark D. Studebaker <mdsxyz123@yahoo.com>, + With assistance from Bruce Allen <ballen@uwm.edu>, and his + fan.c program: http://www.lsc-group.phys.uwm.edu/%7Eballen/driver/ + Gabriele Gorla <gorlik@yahoo.com>, + Jean Delvare <khali@linux-fr.org> + +Description +----------- + +The Standard Microsystems Corporation (SMSC) 47M1xx Super I/O chips +contain monitoring and PWM control circuitry for two fans. + +The 47M15x and 47M192 chips contain a full 'hardware monitoring block' +in addition to the fan monitoring and control. The hardware monitoring +block is not supported by the driver. + +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. + +PWM values are from 0 to 255. + +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 lm_sensors project gratefully acknowledges the support of +Intel in the development of this driver. |