diff options
Diffstat (limited to 'Documentation/hwmon')
| -rw-r--r-- | Documentation/hwmon/ibmaem | 37 | ||||
| -rw-r--r-- | Documentation/hwmon/sysfs-interface | 33 |
2 files changed, 50 insertions, 20 deletions
diff --git a/Documentation/hwmon/ibmaem b/Documentation/hwmon/ibmaem new file mode 100644 index 00000000000..2fefaf582a4 --- /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 f4a8ebc1ef1..2d845730d4e 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. |