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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-06 19:56:51 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-06 19:56:51 -0700 |
commit | 7aefd944f038c7469571adb37769cb6f3924ecfa (patch) | |
tree | f0a8dc23633b6bbbc4f0bff932f332e847fb6c1b /Documentation/hwmon/acpi_power_meter.rst | |
parent | ffa6f55eb6188ee73339cab710fabf30d13110a7 (diff) | |
parent | 39abe9d88b30a51029b0b29a708a4f4459034565 (diff) | |
download | blackbird-op-linux-7aefd944f038c7469571adb37769cb6f3924ecfa.tar.gz blackbird-op-linux-7aefd944f038c7469571adb37769cb6f3924ecfa.zip |
Merge tag 'hwmon-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon updates from Guenter Roeck:
- Add driver for Intersil ISL68137 PWM Controller
- Add driver for Lochnagar 2
- Add driver for Infineon IR38064 Voltage Regulator
- Add support for TMP75B to lm75 driver
- Convert documentation to ReST format
- Use request_muxed_region for Super-IO accesses in several drivers
- Add 'samples' attribute to ABI, and start using it
- Add support for custom sysfs attributes to pmbus drivers (used in
ISL68137 driver)
- Introduce HWMON_CHANNEL_INFO macro
- Automated changes:
- Use permission specific [SENSOR_][DEVICE_]ATTR variants
- Fix build warnings due to unused of_device_id structures
- Use HWMON_CHANNEL_INFO macro
- Various minor improvements and fixes
* tag 'hwmon-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: (125 commits)
hwmon: (lm75) Add support for TMP75B
dt-bindings: hwmon: Add tmp75b to lm75.txt
hwmon: (s3c) Use dev_get_drvdata()
hwmon: (max6650) Drop call to thermal_cdev_update
docs: hwmon: remove the extension from .rst files
docs: hwmon: convert three docs to ReST format
hwmon: (max6650) add thermal cooling device capability
hwmon: (ina3221) Add voltage conversion time settings
hwmon: (ina3221) Do not read-back to cache reg_config
docs: hwmon: Add an index file and rename docs to *.rst
docs: hwmon: convert remaining files to ReST format
docs: hwmon: misc files: convert to ReST format
docs: hwmon: pmbus files: convert to ReST format
docs: hwmon: k8temp, w83793: convert to ReST format
docs: hwmon: da9052, da9055: convert to ReST format
docs: hwmon: wm831x, wm8350: convert to ReST format
docs: hwmon: dme1737, vt1211: convert to ReST format
docs: hwmon: ads1015: convert to ReST format
docs: hwmon: asc7621: convert to ReST format
docs: hwmon: ibmpowernv: convert to ReST format
...
Diffstat (limited to 'Documentation/hwmon/acpi_power_meter.rst')
-rw-r--r-- | Documentation/hwmon/acpi_power_meter.rst | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/Documentation/hwmon/acpi_power_meter.rst b/Documentation/hwmon/acpi_power_meter.rst new file mode 100644 index 000000000000..4a0941ade0ca --- /dev/null +++ b/Documentation/hwmon/acpi_power_meter.rst @@ -0,0 +1,54 @@ +Kernel driver power_meter +========================= + +This driver talks to ACPI 4.0 power meters. + +Supported systems: + + * Any recent system with ACPI 4.0. + + Prefix: 'power_meter' + + Datasheet: http://acpi.info/, section 10.4. + +Author: Darrick J. Wong + +Description +----------- + +This driver implements sensor reading support for the power meters exposed in +the ACPI 4.0 spec (Chapter 10.4). These devices have a simple set of +features--a power meter that returns average power use over a configurable +interval, an optional capping mechanism, and a couple of trip points. The +sysfs interface conforms with the specification outlined in the "Power" section +of Documentation/hwmon/sysfs-interface.rst. + +Special Features +---------------- + +The `power[1-*]_is_battery` knob indicates if the power supply is a battery. +Both `power[1-*]_average_{min,max}` must be set before the trip points will work. +When both of them are set, an ACPI event will be broadcast on the ACPI netlink +socket and a poll notification will be sent to the appropriate +`power[1-*]_average` sysfs file. + +The `power[1-*]_{model_number, serial_number, oem_info}` fields display +arbitrary strings that ACPI provides with the meter. The measures/ directory +contains symlinks to the devices that this meter measures. + +Some computers have the ability to enforce a power cap in hardware. If this is +the case, the `power[1-*]_cap` and related sysfs files will appear. When the +average power consumption exceeds the cap, an ACPI event will be broadcast on +the netlink event socket and a poll notification will be sent to the +appropriate `power[1-*]_alarm` file to indicate that capping has begun, and the +hardware has taken action to reduce power consumption. Most likely this will +result in reduced performance. + +There are a few other ACPI notifications that can be sent by the firmware. In +all cases the ACPI event will be broadcast on the ACPI netlink event socket as +well as sent as a poll notification to a sysfs file. The events are as +follows: + +`power[1-*]_cap` will be notified if the firmware changes the power cap. +`power[1-*]_interval` will be notified if the firmware changes the averaging +interval. |