hwmon: enhance the sysfs API for power meters
Darrick J. Wong [Mon, 26 Oct 2009 23:50:07 +0000 (16:50 -0700)]
Augment the documentation of the hwmon sysfs API to accomodate ACPI power
meters and the current desired behavior of power capping hardware drivers.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/hwmon/sysfs-interface

index dcbd502..82def88 100644 (file)
@@ -353,10 +353,20 @@ power[1-*]_average                Average power use
                                Unit: microWatt
                                RO
 
-power[1-*]_average_interval    Power use averaging interval
+power[1-*]_average_interval    Power use averaging interval.  A poll
+                               notification is sent to this file if the
+                               hardware changes the averaging interval.
                                Unit: milliseconds
                                RW
 
+power[1-*]_average_interval_max        Maximum power use averaging interval
+                               Unit: milliseconds
+                               RO
+
+power[1-*]_average_interval_min        Minimum power use averaging interval
+                               Unit: milliseconds
+                               RO
+
 power[1-*]_average_highest     Historical average maximum power use
                                Unit: microWatt
                                RO
@@ -365,6 +375,18 @@ power[1-*]_average_lowest  Historical average minimum power use
                                Unit: microWatt
                                RO
 
+power[1-*]_average_max         A poll notification is sent to
+                               power[1-*]_average when power use
+                               rises above this value.
+                               Unit: microWatt
+                               RW
+
+power[1-*]_average_min         A poll notification is sent to
+                               power[1-*]_average when power use
+                               sinks below this value.
+                               Unit: microWatt
+                               RW
+
 power[1-*]_input               Instantaneous power use
                                Unit: microWatt
                                RO
@@ -381,6 +403,39 @@ power[1-*]_reset_history   Reset input_highest, input_lowest,
                                average_highest and average_lowest.
                                WO
 
+power[1-*]_accuracy            Accuracy of the power meter.
+                               Unit: Percent
+                               RO
+
+power[1-*]_alarm               1 if the system is drawing more power than the
+                               cap allows; 0 otherwise.  A poll notification is
+                               sent to this file when the power use exceeds the
+                               cap.  This file only appears if the cap is known
+                               to be enforced by hardware.
+                               RO
+
+power[1-*]_cap                 If power use rises above this limit, the
+                               system should take action to reduce power use.
+                               A poll notification is sent to this file if the
+                               cap is changed by the hardware.  The *_cap
+                               files only appear if the cap is known to be
+                               enforced by hardware.
+                               Unit: microWatt
+                               RW
+
+power[1-*]_cap_hyst            Margin of hysteresis built around capping and
+                               notification.
+                               Unit: microWatt
+                               RW
+
+power[1-*]_cap_max             Maximum cap that can be set.
+                               Unit: microWatt
+                               RO
+
+power[1-*]_cap_min             Minimum cap that can be set.
+                               Unit: microWatt
+                               RO
+
 **********
 * Energy *
 **********