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1 | Kernel driver smsc47m1 | ||
2 | ====================== | ||
3 | |||
4 | Supported 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 | |||
16 | Authors: | ||
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 | |||
23 | Description | ||
24 | ----------- | ||
25 | |||
26 | The Standard Microsystems Corporation (SMSC) 47M1xx Super I/O chips | ||
27 | contain monitoring and PWM control circuitry for two fans. | ||
28 | |||
29 | The 47M15x and 47M192 chips contain a full 'hardware monitoring block' | ||
30 | in addition to the fan monitoring and control. The hardware monitoring | ||
31 | block is not supported by the driver. | ||
32 | |||
33 | Fan rotation speeds are reported in RPM (rotations per minute). An alarm is | ||
34 | triggered if the rotation speed has dropped below a programmable limit. Fan | ||
35 | readings can be divided by a programmable divider (1, 2, 4 or 8) to give | ||
36 | the readings more range or accuracy. Not all RPM values can accurately be | ||
37 | represented, so some rounding is done. With a divider of 2, the lowest | ||
38 | representable value is around 2600 RPM. | ||
39 | |||
40 | PWM values are from 0 to 255. | ||
41 | |||
42 | If an alarm triggers, it will remain triggered until the hardware register | ||
43 | is read at least once. This means that the cause for the alarm may | ||
44 | already have disappeared! Note that in the current implementation, all | ||
45 | hardware registers are read whenever any data is read (unless it is less | ||
46 | than 1.5 seconds since the last update). This means that you can easily | ||
47 | miss once-only alarms. | ||
48 | |||
49 | |||
50 | ********************** | ||
51 | The lm_sensors project gratefully acknowledges the support of | ||
52 | Intel in the development of this driver. | ||