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R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +00001Kernel driver smsc47m1
2======================
3
4Supported chips:
5 * SMSC LPC47B27x, LPC47M10x, LPC47M13x, LPC47M14x, LPC47M15x and LPC47M192
6 Addresses scanned: none, address read from Super I/O config space
7 Prefix: 'smsc47m1'
8 Datasheets:
9 http://www.smsc.com/main/datasheets/47b27x.pdf
10 http://www.smsc.com/main/datasheets/47m10x.pdf
11 http://www.smsc.com/main/tools/discontinued/47m13x.pdf
12 http://www.smsc.com/main/datasheets/47m14x.pdf
13 http://www.smsc.com/main/tools/discontinued/47m15x.pdf
14 http://www.smsc.com/main/datasheets/47m192.pdf
15
16Authors:
17 Mark D. Studebaker <mdsxyz123@yahoo.com>,
18 With assistance from Bruce Allen <ballen@uwm.edu>, and his
19 fan.c program: http://www.lsc-group.phys.uwm.edu/%7Eballen/driver/
20 Gabriele Gorla <gorlik@yahoo.com>,
21 Jean Delvare <khali@linux-fr.org>
22
23Description
24-----------
25
26The Standard Microsystems Corporation (SMSC) 47M1xx Super I/O chips
27contain monitoring and PWM control circuitry for two fans.
28
29The 47M15x and 47M192 chips contain a full 'hardware monitoring block'
30in addition to the fan monitoring and control. The hardware monitoring
31block is not supported by the driver.
32
33Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
34triggered if the rotation speed has dropped below a programmable limit. Fan
35readings can be divided by a programmable divider (1, 2, 4 or 8) to give
36the readings more range or accuracy. Not all RPM values can accurately be
37represented, so some rounding is done. With a divider of 2, the lowest
38representable value is around 2600 RPM.
39
40PWM values are from 0 to 255.
41
42If an alarm triggers, it will remain triggered until the hardware register
43is read at least once. This means that the cause for the alarm may
44already have disappeared! Note that in the current implementation, all
45hardware registers are read whenever any data is read (unless it is less
46than 1.5 seconds since the last update). This means that you can easily
47miss once-only alarms.
48
49
50**********************
51The lm_sensors project gratefully acknowledges the support of
52Intel in the development of this driver.