3 files changed, 52 insertions, 21 deletions

diff --git a/Documentation/hwmon/adt7473 b/Documentation/hwmon/adt7473
index 22d8b19046ab..2126de34c711 100644
--- a/Documentation/hwmon/adt7473
+++ b/Documentation/hwmon/adt7473
@@ -69,7 +69,8 @@ point2: Set the pwm speed at a higher temperature bound.
 
 The ADT7473 will scale the pwm between the lower and higher pwm speed when
 the temperature is between the two temperature boundaries.  PWM values range
-from 0 (off) to 255 (full speed).
+from 0 (off) to 255 (full speed).  Fan speed will be set to maximum when the
+temperature sensor associated with the PWM control exceeds temp#_max.
 
 Notes
 -----
diff --git a/Documentation/hwmon/ibmaem b/Documentation/hwmon/ibmaem
new file mode 100644
index 000000000000..2fefaf582a43
--- /dev/null
+++ b/Documentation/hwmon/ibmaem
@@ -0,0 +1,37 @@
+Kernel driver ibmaem
+======================
+
+Supported systems:
+  * Any recent IBM System X server with Active Energy Manager support.
+    This includes the x3350, x3550, x3650, x3655, x3755, x3850 M2,
+    x3950 M2, and certain HS2x/LS2x/QS2x blades.  The IPMI host interface
+    driver ("ipmi-si") needs to be loaded for this driver to do anything.
+    Prefix: 'ibmaem'
+    Datasheet: Not available
+
+Author: Darrick J. Wong
+
+Description
+-----------
+
+This driver implements sensor reading support for the energy and power
+meters available on various IBM System X hardware through the BMC.  All
+sensor banks will be exported as platform devices; this driver can talk
+to both v1 and v2 interfaces.  This driver is completely separate from the
+older ibmpex driver.
+
+The v1 AEM interface has a simple set of features to monitor energy use.
+There is a register that displays an estimate of raw energy consumption
+since the last BMC reset, and a power sensor that returns average power
+use over a configurable interval.
+
+The v2 AEM interface is a bit more sophisticated, being able to present
+a wider range of energy and power use registers, the power cap as
+set by the AEM software, and temperature sensors.
+
+Special Features
+----------------
+
+The "power_cap" value displays the current system power cap, as set by
+the Active Energy Manager software.  Setting the power cap from the host
+is not currently supported.
diff --git a/Documentation/hwmon/sysfs-interface b/Documentation/hwmon/sysfs-interface
index f4a8ebc1ef1a..2d845730d4e0 100644
--- a/Documentation/hwmon/sysfs-interface
+++ b/Documentation/hwmon/sysfs-interface
@@ -2,17 +2,12 @@ Naming and data format standards for sysfs files
 ------------------------------------------------
 
 The libsensors library offers an interface to the raw sensors data
-through the sysfs interface. See libsensors documentation and source for
-further information. As of writing this document, libsensors
-(from lm_sensors 2.8.3) is heavily chip-dependent. Adding or updating
-support for any given chip requires modifying the library's code.
-This is because libsensors was written for the procfs interface
-older kernel modules were using, which wasn't standardized enough.
-Recent versions of libsensors (from lm_sensors 2.8.2 and later) have
-support for the sysfs interface, though.
-
-The new sysfs interface was designed to be as chip-independent as
-possible.
+through the sysfs interface. Since lm-sensors 3.0.0, libsensors is
+completely chip-independent. It assumes that all the kernel drivers
+implement the standard sysfs interface described in this document.
+This makes adding or updating support for any given chip very easy, as
+libsensors, and applications using it, do not need to be modified.
+This is a major improvement compared to lm-sensors 2.
 
 Note that motherboards vary widely in the connections to sensor chips.
 There is no standard that ensures, for example, that the second
@@ -35,19 +30,17 @@ access this data in a simple and consistent way. That said, such programs
 will have to implement conversion, labeling and hiding of inputs. For
 this reason, it is still not recommended to bypass the library.
 
-If you are developing a userspace application please send us feedback on
-this standard.
-
-Note that this standard isn't completely established yet, so it is subject
-to changes. If you are writing a new hardware monitoring driver those
-features can't seem to fit in this interface, please contact us with your
-extension proposal. Keep in mind that backward compatibility must be
-preserved.
-
 Each chip gets its own directory in the sysfs /sys/devices tree.  To
 find all sensor chips, it is easier to follow the device symlinks from
 /sys/class/hwmon/hwmon*.
 
+Up to lm-sensors 3.0.0, libsensors looks for hardware monitoring attributes
+in the "physical" device directory. Since lm-sensors 3.0.1, attributes found
+in the hwmon "class" device directory are also supported. Complex drivers
+(e.g. drivers for multifunction chips) may want to use this possibility to
+avoid namespace pollution. The only drawback will be that older versions of
+libsensors won't support the driver in question.
+
 All sysfs values are fixed point numbers.
 
 There is only one value per file, unlike the older /proc specification.