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/main/datasheets/47b27x.pdf
11        http://www.smsc.com/main/datasheets/47m10x.pdf
12        http://www.smsc.com/main/datasheets/47m112.pdf
13        http://www.smsc.com/main/tools/discontinued/47m13x.pdf
14        http://www.smsc.com/main/datasheets/47m14x.pdf
15        http://www.smsc.com/main/tools/discontinued/47m15x.pdf
16        http://www.smsc.com/main/datasheets/47m192.pdf
17  * SMSC LPC47M292
18    Addresses scanned: none, address read from Super I/O config space
19    Prefix: 'smsc47m2'
20    Datasheet: Not public
21  * SMSC LPC47M997
22    Addresses scanned: none, address read from Super I/O config space
23    Prefix: 'smsc47m1'
24    Datasheet: none
25
26Authors:
27        Mark D. Studebaker <mdsxyz123@yahoo.com>,
28        With assistance from Bruce Allen <ballen@uwm.edu>, and his
29        fan.c program: http://www.lsc-group.phys.uwm.edu/%7Eballen/driver/
30        Gabriele Gorla <gorlik@yahoo.com>,
31        Jean Delvare <khali@linux-fr.org>
32
33Description
34-----------
35
36The Standard Microsystems Corporation (SMSC) 47M1xx Super I/O chips
37contain monitoring and PWM control circuitry for two fans.
38
39The LPC47M15x, LPC47M192 and LPC47M292 chips contain a full 'hardware
40monitoring block' in addition to the fan monitoring and control. The
41hardware monitoring block is not supported by this driver, use the
42smsc47m192 driver for that.
43
44No documentation is available for the 47M997, but it has the same device
45ID as the 47M15x and 47M192 chips and seems to be compatible.
46
47Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
48triggered if the rotation speed has dropped below a programmable limit. Fan
49readings can be divided by a programmable divider (1, 2, 4 or 8) to give
50the readings more range or accuracy. Not all RPM values can accurately be
51represented, so some rounding is done. With a divider of 2, the lowest
52representable value is around 2600 RPM.
53
54PWM values are from 0 to 255.
55
56If an alarm triggers, it will remain triggered until the hardware register
57is read at least once. This means that the cause for the alarm may
58already have disappeared! Note that in the current implementation, all
59hardware registers are read whenever any data is read (unless it is less
60than 1.5 seconds since the last update). This means that you can easily
61miss once-only alarms.
62
63
64**********************
65The lm_sensors project gratefully acknowledges the support of
66Intel in the development of this driver.
67