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Steve Glendinning9df73052010-08-14 21:08:54 +02001Kernel driver emc2103
2======================
3
4Supported chips:
5 * SMSC EMC2103
6 Addresses scanned: I2C 0x2e
7 Prefix: 'emc2103'
8 Datasheet: Not public
9
10Authors:
11 Steve Glendinning <steve.glendinning@smsc.com>
12
13Description
14-----------
15
16The Standard Microsystems Corporation (SMSC) EMC2103 chips
17contain up to 4 temperature sensors and a single fan controller.
18
19Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
20triggered if the rotation speed has dropped below a programmable limit. Fan
21readings can be divided by a programmable divider (1, 2, 4 or 8) to give
22the readings more range or accuracy. Not all RPM values can accurately be
23represented, so some rounding is done. With a divider of 1, the lowest
24representable value is 480 RPM.
25
26This driver supports RPM based control, to use this a fan target
27should be written to fan1_target and pwm1_enable should be set to 3.
28
29The 2103-2 and 2103-4 variants have a third temperature sensor, which can
30be connected to two anti-parallel diodes. These values can be read
31as temp3 and temp4. If only one diode is attached to this channel, temp4
32will show as "fault". The module parameter "apd=0" can be used to suppress
33this 4th channel when anti-parallel diodes are not fitted.