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-rw-r--r--Documentation/hwmon/hwmon-kernel-api.txt3
-rw-r--r--Documentation/hwmon/ltc299024
2 files changed, 17 insertions, 10 deletions
diff --git a/Documentation/hwmon/hwmon-kernel-api.txt b/Documentation/hwmon/hwmon-kernel-api.txt
index 53a806696c64..eb7a78aebb38 100644
--- a/Documentation/hwmon/hwmon-kernel-api.txt
+++ b/Documentation/hwmon/hwmon-kernel-api.txt
@@ -71,7 +71,8 @@ hwmon_device_register_with_info is the most comprehensive and preferred means
to register a hardware monitoring device. It creates the standard sysfs
attributes in the hardware monitoring core, letting the driver focus on reading
from and writing to the chip instead of having to bother with sysfs attributes.
-Its parameters are described in more detail below.
+The parent device parameter cannot be NULL with non-NULL chip info. Its
+parameters are described in more detail below.
devm_hwmon_device_register_with_info is similar to
hwmon_device_register_with_info. However, it is device managed, meaning the
diff --git a/Documentation/hwmon/ltc2990 b/Documentation/hwmon/ltc2990
index c25211e90bdc..3ed68f676c0f 100644
--- a/Documentation/hwmon/ltc2990
+++ b/Documentation/hwmon/ltc2990
@@ -8,6 +8,7 @@ Supported chips:
Datasheet: http://www.linear.com/product/ltc2990
Author: Mike Looijmans <mike.looijmans@topic.nl>
+ Tom Levens <tom.levens@cern.ch>
Description
@@ -16,10 +17,8 @@ Description
LTC2990 is a Quad I2C Voltage, Current and Temperature Monitor.
The chip's inputs can measure 4 voltages, or two inputs together (1+2 and 3+4)
can be combined to measure a differential voltage, which is typically used to
-measure current through a series resistor, or a temperature.
-
-This driver currently uses the 2x differential mode only. In order to support
-other modes, the driver will need to be expanded.
+measure current through a series resistor, or a temperature with an external
+diode.
Usage Notes
@@ -32,12 +31,19 @@ devices explicitly.
Sysfs attributes
----------------
+in0_input Voltage at Vcc pin in millivolt (range 2.5V to 5V)
+temp1_input Internal chip temperature in millidegrees Celcius
+
+A subset of the following attributes are visible, depending on the measurement
+mode of the chip.
+
+in[1-4]_input Voltage at V[1-4] pin in millivolt
+temp2_input External temperature sensor TR1 in millidegrees Celcius
+temp3_input External temperature sensor TR2 in millidegrees Celcius
+curr1_input Current in mA across V1-V2 assuming a 1mOhm sense resistor
+curr2_input Current in mA across V3-V4 assuming a 1mOhm sense resistor
+
The "curr*_input" measurements actually report the voltage drop across the
input pins in microvolts. This is equivalent to the current through a 1mOhm
sense resistor. Divide the reported value by the actual sense resistor value
in mOhm to get the actual value.
-
-in0_input Voltage at Vcc pin in millivolt (range 2.5V to 5V)
-temp1_input Internal chip temperature in millidegrees Celcius
-curr1_input Current in mA across v1-v2 assuming a 1mOhm sense resistor.
-curr2_input Current in mA across v3-v4 assuming a 1mOhm sense resistor.