1Kernel driver smsc47m1
2======================
3
4Supported chips:
5  * SMSC LPC47B27x, LPC47M112, LPC47M10x, LPC47M13x, LPC47M14x,
6    LPC47M15x and LPC47M192
7    Addresses scanned: none, address read from Super I/O config space
8    Prefix: 'smsc47m1'
9    Datasheets:
10        http://www.smsc.com/media/Downloads_Public/Data_Sheets/47b272.pdf
11        http://www.smsc.com/media/Downloads_Public/Data_Sheets/47m10x.pdf
12        http://www.smsc.com/media/Downloads_Public/Data_Sheets/47m112.pdf
13        http://www.smsc.com/
14  * SMSC LPC47M292
15    Addresses scanned: none, address read from Super I/O config space
16    Prefix: 'smsc47m2'
17    Datasheet: Not public
18  * SMSC LPC47M997
19    Addresses scanned: none, address read from Super I/O config space
20    Prefix: 'smsc47m1'
21    Datasheet: none
22
23Authors:
24        Mark D. Studebaker <mdsxyz123@yahoo.com>,
25        With assistance from Bruce Allen <ballen@uwm.edu>, and his
26        fan.c program: http://www.lsc-group.phys.uwm.edu/%7Eballen/driver/
27        Gabriele Gorla <gorlik@yahoo.com>,
28        Jean Delvare <jdelvare@suse.de>
29
30Description
31-----------
32
33The Standard Microsystems Corporation (SMSC) 47M1xx Super I/O chips
34contain monitoring and PWM control circuitry for two fans.
35
36The LPC47M15x, LPC47M192 and LPC47M292 chips contain a full 'hardware
37monitoring block' in addition to the fan monitoring and control. The
38hardware monitoring block is not supported by this driver, use the
39smsc47m192 driver for that.
40
41No documentation is available for the 47M997, but it has the same device
42ID as the 47M15x and 47M192 chips and seems to be compatible.
43
44Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
45triggered if the rotation speed has dropped below a programmable limit. Fan
46readings can be divided by a programmable divider (1, 2, 4 or 8) to give
47the readings more range or accuracy. Not all RPM values can accurately be
48represented, so some rounding is done. With a divider of 2, the lowest
49representable value is around 2600 RPM.
50
51PWM values are from 0 to 255.
52
53If an alarm triggers, it will remain triggered until the hardware register
54is read at least once. This means that the cause for the alarm may
55already have disappeared! Note that in the current implementation, all
56hardware registers are read whenever any data is read (unless it is less
57than 1.5 seconds since the last update). This means that you can easily
58miss once-only alarms.
59
60
61**********************
62The lm_sensors project gratefully acknowledges the support of
63Intel in the development of this driver.
64