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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-06 19:56:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-06 19:56:51 -0700
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treef0a8dc23633b6bbbc4f0bff932f332e847fb6c1b /Documentation/hwmon/acpi_power_meter.rst
parentffa6f55eb6188ee73339cab710fabf30d13110a7 (diff)
parent39abe9d88b30a51029b0b29a708a4f4459034565 (diff)
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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 ...
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+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.
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