Merge branches 'acpi-battery', 'acpi-video', 'acpi-fan' and 'acpi-drivers'

* acpi-battery:
  ACPI / battery: Deal better with neither design nor full capacity not being reported
  ACPI / battery: Use design-cap for capacity calculations if full-cap is not available
  ACPI / battery: Deal with design or full capacity being reported as -1

* acpi-video:
  ACPI: video: Do not export a non working backlight interface on MSI MS-7721 boards
  ACPI: video: Use native backlight on Lenovo E41-25/45
  ACPI: video: fix typo in comment

* acpi-fan:
  ACPI: fan: Expose fan performance state information

* acpi-drivers:
  thermal: int340x_thermal: Add Tiger Lake ACPI device IDs
  platform/x86: intel-hid: Add Tiger Lake ACPI device ID
  ACPI: fan: Add Tiger Lake ACPI device ID
  ACPI: DPTF: Add Tiger Lake ACPI device IDs

Documentation/admin-guide/acpi/fan_performance_states.rst

@@ -0,0 +1,62 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========================
+ACPI Fan Performance States
+===========================
+
+When the optional _FPS object is present under an ACPI device representing a
+fan (for example, PNP0C0B or INT3404), the ACPI fan driver creates additional
+"state*" attributes in the sysfs directory of the ACPI device in question.
+These attributes list properties of fan performance states.
+
+For more information on _FPS refer to the ACPI specification at:
+
+http://uefi.org/specifications
+
+For instance, the contents of the INT3404 ACPI device sysfs directory
+may look as follows::
+
+ $ ls -l /sys/bus/acpi/devices/INT3404:00/
+ total 0
+...
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state0
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state1
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state10
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state11
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state2
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state3
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state4
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state5
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state6
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state7
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state8
+ -r--r--r-- 1 root root 4096 Dec 13 20:38 state9
+ -r--r--r-- 1 root root 4096 Dec 13 01:00 status
+ ...
+
+where each of the "state*" files represents one performance state of the fan
+and contains a colon-separated list of 5 integer numbers (fields) with the
+following interpretation::
+
+control_percent:trip_point_index:speed_rpm:noise_level_mdb:power_mw
+
+* ``control_percent``: The percent value to be used to set the fan speed to a
+  specific level using the _FSL object (0-100).
+
+* ``trip_point_index``: The active cooling trip point number that corresponds
+  to this performance state (0-9).
+
+* ``speed_rpm``: Speed of the fan in rotations per minute.
+
+* ``noise_level_mdb``: Audible noise emitted by the fan in this state in
+  millidecibels.
+
+* ``power_mw``: Power draw of the fan in this state in milliwatts.
+
+For example::
+
+ $cat /sys/bus/acpi/devices/INT3404:00/state1
+ 25:0:3200:12500:1250
+
+When a given field is not populated or its value provided by the platform
+firmware is invalid, the "not-defined" string is shown instead of the value.

Documentation/admin-guide/acpi/index.rst

@@ -12,3 +12,4 @@ the Linux ACPI support.
    dsdt-override
    ssdt-overlays
    cppc_sysfs
+   fan_performance_states