1Kernel 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. 34