[mirror_ubuntu-bionic-kernel.git] / Documentation / hwmon / emc2103

Kernel driver emc2103
======================

Supported chips:
  * SMSC EMC2103
    Addresses scanned: I2C 0x2e
    Prefix: 'emc2103'
    Datasheet: Not public

Authors:
        Steve Glendinning <steve.glendinning@smsc.com>

Description
-----------

The Standard Microsystems Corporation (SMSC) EMC2103 chips
contain up to 4 temperature sensors and a single fan controller.

Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
triggered if the rotation speed has dropped below a programmable limit. Fan
readings can be divided by a programmable divider (1, 2, 4 or 8) to give
the readings more range or accuracy. Not all RPM values can accurately be
represented, so some rounding is done. With a divider of 1, the lowest
representable value is 480 RPM.

This driver supports RPM based control, to use this a fan target
should be written to fan1_target and pwm1_enable should be set to 3.

The 2103-2 and 2103-4 variants have a third temperature sensor, which can
be connected to two anti-parallel diodes.  These values can be read
as temp3 and temp4.  If only one diode is attached to this channel, temp4
will show as "fault".  The module parameter "apd=0" can be used to suppress
this 4th channel when anti-parallel diodes are not fitted.
Commit	Line	Data
9df7305b SG	1	Kernel driver emc2103
	2	======================
	3
	4	Supported chips:
	5	* SMSC EMC2103
	6	Addresses scanned: I2C 0x2e
	7	Prefix: 'emc2103'
	8	Datasheet: Not public
	9
	10	Authors:
	11	Steve Glendinning <steve.glendinning@smsc.com>
	12
	13	Description
	14	-----------
	15
	16	The Standard Microsystems Corporation (SMSC) EMC2103 chips
	17	contain up to 4 temperature sensors and a single fan controller.
	18
	19	Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
	20	triggered if the rotation speed has dropped below a programmable limit. Fan
	21	readings can be divided by a programmable divider (1, 2, 4 or 8) to give
	22	the readings more range or accuracy. Not all RPM values can accurately be
	23	represented, so some rounding is done. With a divider of 1, the lowest
	24	representable value is 480 RPM.
	25
	26	This driver supports RPM based control, to use this a fan target
	27	should be written to fan1_target and pwm1_enable should be set to 3.
	28
	29	The 2103-2 and 2103-4 variants have a third temperature sensor, which can
	30	be connected to two anti-parallel diodes. These values can be read
	31	as temp3 and temp4. If only one diode is attached to this channel, temp4
	32	will show as "fault". The module parameter "apd=0" can be used to suppress
	33	this 4th channel when anti-parallel diodes are not fitted.