Merge tag 'acpi-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI updates from Rafael Wysocki:
 "These rearrange the ACPI documentation by converting it to the .rst
  format and splitting it into clear categories (admin guide, driver
  API, firmware guide), switch over multiple users of a problematic
  library function to a new better one, update the ACPICA code in the
  kernel to a new upstream release, fix a few issues, improve power
  device management diagnostics and do some cleanups.

  Specifics:

   - Convert the ACPI documentation in the kernel source tree to the
     .rst format and split it into the admin guide, driver API and
     firmware guide parts (Changbin Du).

   - Add a PRP0001 usage example to the ACPI documentation (Thomas
     Preston).

   - Switch over the users of the acpi_dev_get_first_match_name()
     library function which turned out to be problematic to a new,
     better one called acpi_dev_get_first_match_dev() (Andy Shevchenko,
     YueHaibing).

   - Update the ACPICA code in the kernel to upstream release 20190405
     including:
       * Null pointer dereference check in acpi_ns_delete_node() (Erik
         Schmauss).
       * Multiple macro and function name changes (Bob Moore).
       * Predefined operation region name fix (Erik Schmauss).

   - Fix hibernation issue on systems using the Baytrail and Cherrytrail
     Intel SoCs introduced during the 4.20 development cycle (Hans de
     Goede).

   - Add Sony VPCEH3U1E to the backlight quirk list (Zhang Rui).

   - Fix button handling during system resume (Zhang Rui).

   - Add a device PM diagnostic message (Rafael Wysocki).

   - Clean up the code, comments and white space in multiple places
     (Bjorn Helgaas, Gustavo Silva, Kefeng Wang)"

* tag 'acpi-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (53 commits)
  Documentation: ACPI: move video_extension.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move ssdt-overlays.txt to admin-guide/acpi and convert to reST
  Documentation: ACPI: move lpit.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move cppc_sysfs.txt to admin-guide/acpi and convert to reST
  Documentation: ACPI: move apei/einj.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move apei/output_format.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move aml-debugger.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move method-tracing.txt to firmware-guide/acpi and convert to rsST
  Documentation: ACPI: move debug.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move dsd/data-node-references.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move dsd/graph.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move acpi-lid.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move i2c-muxes.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move dsdt-override.txt to admin-guide/acpi and convert to reST
  Documentation: ACPI: move initrd_table_override.txt to admin-guide/acpi and convert to reST
  Documentation: ACPI: move method-customizing.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move gpio-properties.txt to firmware-guide/acpi and convert to reST
  Documentation: ACPI: move DSD-properties-rules.txt to firmware-guide/acpi and covert to reST
  Documentation: ACPI: move scan_handlers.txt to driver-api/acpi and convert to reST
  Documentation: ACPI: move linuxized-acpica.txt to driver-api/acpi and convert to reST
  ...

4 files changed, 372 insertions, 0 deletions

diff --git a/Documentation/driver-api/acpi/index.rst b/Documentation/driver-api/acpi/index.rst
new file mode 100644
index 000000000000..ace0008e54c2
--- /dev/null
+++ b/Documentation/driver-api/acpi/index.rst
@@ -0,0 +1,9 @@
+============
+ACPI Support
+============
+
+.. toctree::
+   :maxdepth: 2
+
+   linuxized-acpica
+   scan_handlers
diff --git a/Documentation/driver-api/acpi/linuxized-acpica.rst b/Documentation/driver-api/acpi/linuxized-acpica.rst
new file mode 100644
index 000000000000..0ca8f1538519
--- /dev/null
+++ b/Documentation/driver-api/acpi/linuxized-acpica.rst
@@ -0,0 +1,279 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. include:: <isonum.txt>
+
+============================================================
+Linuxized ACPICA - Introduction to ACPICA Release Automation
+============================================================
+
+:Copyright: |copy| 2013-2016, Intel Corporation
+
+:Author: Lv Zheng <lv.zheng@intel.com>
+
+
+Abstract
+========
+This document describes the ACPICA project and the relationship between
+ACPICA and Linux.  It also describes how ACPICA code in drivers/acpi/acpica,
+include/acpi and tools/power/acpi is automatically updated to follow the
+upstream.
+
+ACPICA Project
+==============
+
+The ACPI Component Architecture (ACPICA) project provides an operating
+system (OS)-independent reference implementation of the Advanced
+Configuration and Power Interface Specification (ACPI).  It has been
+adapted by various host OSes.  By directly integrating ACPICA, Linux can
+also benefit from the application experiences of ACPICA from other host
+OSes.
+
+The homepage of ACPICA project is: www.acpica.org, it is maintained and
+supported by Intel Corporation.
+
+The following figure depicts the Linux ACPI subsystem where the ACPICA
+adaptation is included::
+
+      +---------------------------------------------------------+
+      |                                                         |
+      |   +---------------------------------------------------+ |
+      |   | +------------------+                              | |
+      |   | | Table Management |                              | |
+      |   | +------------------+                              | |
+      |   | +----------------------+                          | |
+      |   | | Namespace Management |                          | |
+      |   | +----------------------+                          | |
+      |   | +------------------+       ACPICA Components      | |
+      |   | | Event Management |                              | |
+      |   | +------------------+                              | |
+      |   | +---------------------+                           | |
+      |   | | Resource Management |                           | |
+      |   | +---------------------+                           | |
+      |   | +---------------------+                           | |
+      |   | | Hardware Management |                           | |
+      |   | +---------------------+                           | |
+      | +---------------------------------------------------+ | |
+      | | |                            +------------------+ | | |
+      | | |                            | OS Service Layer | | | |
+      | | |                            +------------------+ | | |
+      | | +-------------------------------------------------|-+ |
+      | |   +--------------------+                          |   |
+      | |   | Device Enumeration |                          |   |
+      | |   +--------------------+                          |   |
+      | |   +------------------+                            |   |
+      | |   | Power Management |                            |   |
+      | |   +------------------+     Linux/ACPI Components  |   |
+      | |   +--------------------+                          |   |
+      | |   | Thermal Management |                          |   |
+      | |   +--------------------+                          |   |
+      | |   +--------------------------+                    |   |
+      | |   | Drivers for ACPI Devices |                    |   |
+      | |   +--------------------------+                    |   |
+      | |   +--------+                                      |   |
+      | |   | ...... |                                      |   |
+      | |   +--------+                                      |   |
+      | +---------------------------------------------------+   |
+      |                                                         |
+      +---------------------------------------------------------+
+
+                 Figure 1. Linux ACPI Software Components
+
+.. note::
+    A. OS Service Layer - Provided by Linux to offer OS dependent
+       implementation of the predefined ACPICA interfaces (acpi_os_*).
+       ::
+
+         include/acpi/acpiosxf.h
+         drivers/acpi/osl.c
+         include/acpi/platform
+         include/asm/acenv.h
+    B. ACPICA Functionality - Released from ACPICA code base to offer
+       OS independent implementation of the ACPICA interfaces (acpi_*).
+       ::
+
+         drivers/acpi/acpica
+         include/acpi/ac*.h
+         tools/power/acpi
+    C. Linux/ACPI Functionality - Providing Linux specific ACPI
+       functionality to the other Linux kernel subsystems and user space
+       programs.
+       ::
+
+         drivers/acpi
+         include/linux/acpi.h
+         include/linux/acpi*.h
+         include/acpi
+         tools/power/acpi
+    D. Architecture Specific ACPICA/ACPI Functionalities - Provided by the
+       ACPI subsystem to offer architecture specific implementation of the
+       ACPI interfaces.  They are Linux specific components and are out of
+       the scope of this document.
+       ::
+
+         include/asm/acpi.h
+         include/asm/acpi*.h
+         arch/*/acpi
+
+ACPICA Release
+==============
+
+The ACPICA project maintains its code base at the following repository URL:
+https://github.com/acpica/acpica.git. As a rule, a release is made every
+month.
+
+As the coding style adopted by the ACPICA project is not acceptable by
+Linux, there is a release process to convert the ACPICA git commits into
+Linux patches.  The patches generated by this process are referred to as
+"linuxized ACPICA patches".  The release process is carried out on a local
+copy the ACPICA git repository.  Each commit in the monthly release is
+converted into a linuxized ACPICA patch.  Together, they form the monthly
+ACPICA release patchset for the Linux ACPI community.  This process is
+illustrated in the following figure::
+
+    +-----------------------------+
+    | acpica / master (-) commits |
+    +-----------------------------+
+       /|\         |
+        |         \|/
+        |  /---------------------\    +----------------------+
+        | < Linuxize repo Utility >-->| old linuxized acpica |--+
+        |  \---------------------/    +----------------------+  |
+        |                                                       |
+     /---------\                                                |
+    < git reset >                                                \
+     \---------/                                                  \
+       /|\                                                        /+-+
+        |                                                        /   |
+    +-----------------------------+                             |    |
+    | acpica / master (+) commits |                             |    |
+    +-----------------------------+                             |    |
+                   |                                            |    |
+                  \|/                                           |    |
+         /-----------------------\    +----------------------+  |    |
+        < Linuxize repo Utilities >-->| new linuxized acpica |--+    |
+         \-----------------------/    +----------------------+       |
+                                                                    \|/
+    +--------------------------+                  /----------------------\
+    | Linuxized ACPICA Patches |<----------------< Linuxize patch Utility >
+    +--------------------------+                  \----------------------/
+                   |
+                  \|/
+     /---------------------------\
+    < Linux ACPI Community Review >
+     \---------------------------/
+                   |
+                  \|/
+    +-----------------------+    /------------------\    +----------------+
+    | linux-pm / linux-next |-->< Linux Merge Window >-->| linux / master |
+    +-----------------------+    \------------------/    +----------------+
+
+                Figure 2. ACPICA -> Linux Upstream Process
+
+.. note::
+    A. Linuxize Utilities - Provided by the ACPICA repository, including a
+       utility located in source/tools/acpisrc folder and a number of
+       scripts located in generate/linux folder.
+    B. acpica / master - "master" branch of the git repository at
+       <https://github.com/acpica/acpica.git>.
+    C. linux-pm / linux-next - "linux-next" branch of the git repository at
+       <http://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git>.
+    D. linux / master - "master" branch of the git repository at
+       <http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git>.
+
+   Before the linuxized ACPICA patches are sent to the Linux ACPI community
+   for review, there is a quality assurance build test process to reduce
+   porting issues.  Currently this build process only takes care of the
+   following kernel configuration options:
+   CONFIG_ACPI/CONFIG_ACPI_DEBUG/CONFIG_ACPI_DEBUGGER
+
+ACPICA Divergences
+==================
+
+Ideally, all of the ACPICA commits should be converted into Linux patches
+automatically without manual modifications, the "linux / master" tree should
+contain the ACPICA code that exactly corresponds to the ACPICA code
+contained in "new linuxized acpica" tree and it should be possible to run
+the release process fully automatically.
+
+As a matter of fact, however, there are source code differences between
+the ACPICA code in Linux and the upstream ACPICA code, referred to as
+"ACPICA Divergences".
+
+The various sources of ACPICA divergences include:
+   1. Legacy divergences - Before the current ACPICA release process was
+      established, there already had been divergences between Linux and
+      ACPICA. Over the past several years those divergences have been greatly
+      reduced, but there still are several ones and it takes time to figure
+      out the underlying reasons for their existence.
+   2. Manual modifications - Any manual modification (eg. coding style fixes)
+      made directly in the Linux sources obviously hurts the ACPICA release
+      automation.  Thus it is recommended to fix such issues in the ACPICA
+      upstream source code and generate the linuxized fix using the ACPICA
+      release utilities (please refer to Section 4 below for the details).
+   3. Linux specific features - Sometimes it's impossible to use the
+      current ACPICA APIs to implement features required by the Linux kernel,
+      so Linux developers occasionally have to change ACPICA code directly.
+      Those changes may not be acceptable by ACPICA upstream and in such cases
+      they are left as committed ACPICA divergences unless the ACPICA side can
+      implement new mechanisms as replacements for them.
+   4. ACPICA release fixups - ACPICA only tests commits using a set of the
+      user space simulation utilities, thus the linuxized ACPICA patches may
+      break the Linux kernel, leaving us build/boot failures.  In order to
+      avoid breaking Linux bisection, fixes are applied directly to the
+      linuxized ACPICA patches during the release process.  When the release
+      fixups are backported to the upstream ACPICA sources, they must follow
+      the upstream ACPICA rules and so further modifications may appear.
+      That may result in the appearance of new divergences.
+   5. Fast tracking of ACPICA commits - Some ACPICA commits are regression
+      fixes or stable-candidate material, so they are applied in advance with
+      respect to the ACPICA release process.  If such commits are reverted or
+      rebased on the ACPICA side in order to offer better solutions, new ACPICA
+      divergences are generated.
+
+ACPICA Development
+==================
+
+This paragraph guides Linux developers to use the ACPICA upstream release
+utilities to obtain Linux patches corresponding to upstream ACPICA commits
+before they become available from the ACPICA release process.
+
+   1. Cherry-pick an ACPICA commit
+
+   First you need to git clone the ACPICA repository and the ACPICA change
+   you want to cherry pick must be committed into the local repository.
+
+   Then the gen-patch.sh command can help to cherry-pick an ACPICA commit
+   from the ACPICA local repository::
+
+   $ git clone https://github.com/acpica/acpica
+   $ cd acpica
+   $ generate/linux/gen-patch.sh -u [commit ID]
+
+   Here the commit ID is the ACPICA local repository commit ID you want to
+   cherry pick.  It can be omitted if the commit is "HEAD".
+
+   2. Cherry-pick recent ACPICA commits
+
+   Sometimes you need to rebase your code on top of the most recent ACPICA
+   changes that haven't been applied to Linux yet.
+
+   You can generate the ACPICA release series yourself and rebase your code on
+   top of the generated ACPICA release patches::
+
+   $ git clone https://github.com/acpica/acpica
+   $ cd acpica
+   $ generate/linux/make-patches.sh -u [commit ID]
+
+   The commit ID should be the last ACPICA commit accepted by Linux.  Usually,
+   it is the commit modifying ACPI_CA_VERSION.  It can be found by executing
+   "git blame source/include/acpixf.h" and referencing the line that contains
+   "ACPI_CA_VERSION".
+
+   3. Inspect the current divergences
+
+   If you have local copies of both Linux and upstream ACPICA, you can generate
+   a diff file indicating the state of the current divergences::
+
+   # git clone https://github.com/acpica/acpica
+   # git clone http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
+   # cd acpica
+   # generate/linux/divergences.sh -s ../linux
diff --git a/Documentation/driver-api/acpi/scan_handlers.rst b/Documentation/driver-api/acpi/scan_handlers.rst
new file mode 100644
index 000000000000..7a197b3a33fc
--- /dev/null
+++ b/Documentation/driver-api/acpi/scan_handlers.rst
@@ -0,0 +1,83 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. include:: <isonum.txt>
+
+==================
+ACPI Scan Handlers
+==================
+
+:Copyright: |copy| 2012, Intel Corporation
+
+:Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+
+During system initialization and ACPI-based device hot-add, the ACPI namespace
+is scanned in search of device objects that generally represent various pieces
+of hardware.  This causes a struct acpi_device object to be created and
+registered with the driver core for every device object in the ACPI namespace
+and the hierarchy of those struct acpi_device objects reflects the namespace
+layout (i.e. parent device objects in the namespace are represented by parent
+struct acpi_device objects and analogously for their children).  Those struct
+acpi_device objects are referred to as "device nodes" in what follows, but they
+should not be confused with struct device_node objects used by the Device Trees
+parsing code (although their role is analogous to the role of those objects).
+
+During ACPI-based device hot-remove device nodes representing pieces of hardware
+being removed are unregistered and deleted.
+
+The core ACPI namespace scanning code in drivers/acpi/scan.c carries out basic
+initialization of device nodes, such as retrieving common configuration
+information from the device objects represented by them and populating them with
+appropriate data, but some of them require additional handling after they have
+been registered.  For example, if the given device node represents a PCI host
+bridge, its registration should cause the PCI bus under that bridge to be
+enumerated and PCI devices on that bus to be registered with the driver core.
+Similarly, if the device node represents a PCI interrupt link, it is necessary
+to configure that link so that the kernel can use it.
+
+Those additional configuration tasks usually depend on the type of the hardware
+component represented by the given device node which can be determined on the
+basis of the device node's hardware ID (HID).  They are performed by objects
+called ACPI scan handlers represented by the following structure::
+
+	struct acpi_scan_handler {
+		const struct acpi_device_id *ids;
+		struct list_head list_node;
+		int (*attach)(struct acpi_device *dev, const struct acpi_device_id *id);
+		void (*detach)(struct acpi_device *dev);
+	};
+
+where ids is the list of IDs of device nodes the given handler is supposed to
+take care of, list_node is the hook to the global list of ACPI scan handlers
+maintained by the ACPI core and the .attach() and .detach() callbacks are
+executed, respectively, after registration of new device nodes and before
+unregistration of device nodes the handler attached to previously.
+
+The namespace scanning function, acpi_bus_scan(), first registers all of the
+device nodes in the given namespace scope with the driver core.  Then, it tries
+to match a scan handler against each of them using the ids arrays of the
+available scan handlers.  If a matching scan handler is found, its .attach()
+callback is executed for the given device node.  If that callback returns 1,
+that means that the handler has claimed the device node and is now responsible
+for carrying out any additional configuration tasks related to it.  It also will
+be responsible for preparing the device node for unregistration in that case.
+The device node's handler field is then populated with the address of the scan
+handler that has claimed it.
+
+If the .attach() callback returns 0, it means that the device node is not
+interesting to the given scan handler and may be matched against the next scan
+handler in the list.  If it returns a (negative) error code, that means that
+the namespace scan should be terminated due to a serious error.  The error code
+returned should then reflect the type of the error.
+
+The namespace trimming function, acpi_bus_trim(), first executes .detach()
+callbacks from the scan handlers of all device nodes in the given namespace
+scope (if they have scan handlers).  Next, it unregisters all of the device
+nodes in that scope.
+
+ACPI scan handlers can be added to the list maintained by the ACPI core with the
+help of the acpi_scan_add_handler() function taking a pointer to the new scan
+handler as an argument.  The order in which scan handlers are added to the list
+is the order in which they are matched against device nodes during namespace
+scans.
+
+All scan handles must be added to the list before acpi_bus_scan() is run for the
+first time and they cannot be removed from it.
diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst
index c0b600ed9961..aa87075c7846 100644
--- a/Documentation/driver-api/index.rst
+++ b/Documentation/driver-api/index.rst
@@ -56,6 +56,7 @@ available subsections can be seen below.
    slimbus
    soundwire/index
    fpga/index
+   acpi/index
 
 .. only::  subproject and html