hwmon: (ltc2978) Add support for LTC3886

[mirror_ubuntu-artful-kernel.git] / Documentation / hwmon / ltc2978

Kernel driver ltc2978
=====================

Supported chips:
  * Linear Technology LTC2974
    Prefix: 'ltc2974'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc2974
  * Linear Technology LTC2975
    Prefix: 'ltc2975'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc2975
  * Linear Technology LTC2977
    Prefix: 'ltc2977'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc2977
  * Linear Technology LTC2978, LTC2978A
    Prefix: 'ltc2978'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc2978
    	       http://www.linear.com/product/ltc2978a
  * Linear Technology LTC2980
    Prefix: 'ltc2980'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc2980
  * Linear Technology LTC3880
    Prefix: 'ltc3880'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc3880
  * Linear Technology LTC3882
    Prefix: 'ltc3882'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc3882
  * Linear Technology LTC3883
    Prefix: 'ltc3883'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc3883
  * Linear Technology LTC3886
    Prefix: 'ltc3886'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc3886
  * Linear Technology LTC3887
    Prefix: 'ltc3887'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltc3887
  * Linear Technology LTM2987
    Prefix: 'ltm2987'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltm2987
  * Linear Technology LTM4676
    Prefix: 'ltm4676'
    Addresses scanned: -
    Datasheet: http://www.linear.com/product/ltm4676

Author: Guenter Roeck <linux@roeck-us.net>


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

LTC2974 and LTC2975 are quad digital power supply managers.
LTC2978 is an octal power supply monitor.
LTC2977 is a pin compatible replacement for LTC2978.
LTC2980 is a 16-channel Power System Manager, consisting of two LTC2977
in a single die. The chip is instantiated and reported as two separate chips
on two different I2C bus addresses.
LTC3880, LTC3882, LTC3886, and LTC3887 are dual output poly-phase step-down
DC/DC controllers.
LTC3883 is a single phase step-down DC/DC controller.
LTM2987 is a 16-channel Power System Manager with two LTC2977 plus
additional components on a single die. The chip is instantiated and reported
as two separate chips on two different I2C bus addresses.
LTM4676 is a dual 13A or single 26A uModule regulator.


Usage Notes
-----------

This driver does not probe for PMBus devices. You will have to instantiate
devices explicitly.

Example: the following commands will load the driver for an LTC2978 at address
0x60 on I2C bus #1:

# modprobe ltc2978
# echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device


Sysfs attributes
----------------

in1_label		"vin"
in1_input		Measured input voltage.
in1_min			Minimum input voltage.
in1_max			Maximum input voltage.
			LTC2974, LTC2975, LTC2977, LTC2980, LTC2978, and
			LTM2987 only.
in1_lcrit		Critical minimum input voltage.
			LTC2974, LTC2975, LTC2977, LTC2980, LTC2978, and
			LTM2987 only.
in1_crit		Critical maximum input voltage.
in1_min_alarm		Input voltage low alarm.
in1_max_alarm		Input voltage high alarm.
			LTC2974, LTC2975, LTC2977, LTC2980, LTC2978, and
			LTM2987 only.
in1_lcrit_alarm		Input voltage critical low alarm.
			LTC2974, LTC2975, LTC2977, LTC2980, LTC2978, and
			LTM2987 only.
in1_crit_alarm		Input voltage critical high alarm.
in1_lowest		Lowest input voltage.
			LTC2974, LTC2975, LTC2977, LTC2980, LTC2978, and
			LTM2987 only.
in1_highest		Highest input voltage.
in1_reset_history	Reset input voltage history.

in[N]_label		"vout[1-8]".
			LTC2974, LTC2975: N=2-5
			LTC2977, LTC2980, LTM2987: N=2-9
			LTC2978: N=2-9
			LTC3880, LTC3882, LTC23886 LTC3887, LTM4676: N=2-3
			LTC3883: N=2
in[N]_input		Measured output voltage.
in[N]_min		Minimum output voltage.
in[N]_max		Maximum output voltage.
in[N]_lcrit		Critical minimum output voltage.
in[N]_crit		Critical maximum output voltage.
in[N]_min_alarm		Output voltage low alarm.
in[N]_max_alarm		Output voltage high alarm.
in[N]_lcrit_alarm	Output voltage critical low alarm.
in[N]_crit_alarm	Output voltage critical high alarm.
in[N]_lowest		Lowest output voltage. LTC2974, LTC2975,
			and LTC2978 only.
in[N]_highest		Highest output voltage.
in[N]_reset_history	Reset output voltage history.

temp[N]_input		Measured temperature.
			On LTC2974 and LTC2975, temp[1-4] report external
			temperatures, and temp5 reports the chip temperature.
			On LTC2977, LTC2980, LTC2978, and LTM2987, only one
			temperature measurement is supported and reports
			the chip temperature.
			On LTC3880, LTC3882, LTC3887, and LTM4676, temp1 and
			temp2 report external temperatures, and temp3 reports
			the chip temperature.
			On LTC3883, temp1 reports an external temperature,
			and temp2 reports the chip temperature.
temp[N]_min		Mimimum temperature. LTC2974, LCT2977, LTM2980, LTC2978,
			and LTM2987 only.
temp[N]_max		Maximum temperature.
temp[N]_lcrit		Critical low temperature.
temp[N]_crit		Critical high temperature.
temp[N]_min_alarm	Temperature low alarm.
			LTC2974, LTC2975, LTC2977, LTM2980, LTC2978, and
			LTM2987 only.
temp[N]_max_alarm	Temperature high alarm.
temp[N]_lcrit_alarm	Temperature critical low alarm.
temp[N]_crit_alarm	Temperature critical high alarm.
temp[N]_lowest		Lowest measured temperature.
			LTC2974, LTC2975, LTC2977, LTM2980, LTC2978, and
			LTM2987 only.
			Not supported for chip temperature sensor on LTC2974 and
			LTC2975.
temp[N]_highest		Highest measured temperature. Not supported for chip
			temperature sensor on LTC2974 and LTC2975.
temp[N]_reset_history	Reset temperature history. Not supported for chip
			temperature sensor on LTC2974 and LTC2975.

power1_label		"pin". LTC3883 and LTC3886 only.
power1_input		Measured input power.

power[N]_label		"pout[1-4]".
			LTC2974, LTC2975: N=1-4
			LTC2977, LTC2980, LTM2987: Not supported
			LTC2978: Not supported
			LTC3880, LTC3882, LTC3886, LTC3887, LTM4676: N=1-2
			LTC3883: N=2
power[N]_input		Measured output power.

curr1_label		"iin". LTC3880, LTC3883, LTC3886, LTC3887, and LTM4676
			only.
curr1_input		Measured input current.
curr1_max		Maximum input current.
curr1_max_alarm		Input current high alarm.
curr1_highest		Highest input current. LTC3883 and LTC3886 only.
curr1_reset_history	Reset input current history. LTC3883 and LTC3886 only.

curr[N]_label		"iout[1-4]".
			LTC2974, LTC2975: N=1-4
			LTC2977, LTC2980, LTM2987: not supported
			LTC2978: not supported
			LTC3880, LTC3882, LTC3886, LTC3887, LTM4676: N=2-3
			LTC3883: N=2
curr[N]_input		Measured output current.
curr[N]_max		Maximum output current.
curr[N]_crit		Critical high output current.
curr[N]_lcrit		Critical low output current. LTC2974 and LTC2975 only.
curr[N]_max_alarm	Output current high alarm.
curr[N]_crit_alarm	Output current critical high alarm.
curr[N]_lcrit_alarm	Output current critical low alarm.
			LTC2974 and LTC2975 only.
curr[N]_lowest		Lowest output current. LTC2974 and LTC2975 only.
curr[N]_highest		Highest output current.
curr[N]_reset_history	Reset output current history.