platform/x86: wmi: Add device specific documentation

Add a place for device-specific documentation of WMI drivers.
The first entry is documentation for the wmi-bmof driver, with
additional documentation being expected to follow.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20230424222939.208137-5-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

6 files changed, 64 insertions, 2 deletions

diff --git a/Documentation/ABI/stable/sysfs-platform-wmi-bmof b/Documentation/ABI/stable/sysfs-platform-wmi-bmof
new file mode 100644
index 000000000000..a786504b6027
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-platform-wmi-bmof
@@ -0,0 +1,7 @@
+What:		/sys/bus/wmi/devices/05901221-D566-11D1-B2F0-00A0C9062910[-X]/bmof
+Date:		Jun 2017
+KernelVersion:	4.13
+Description:
+		Binary MOF metadata used to decribe the details of available ACPI WMI interfaces.
+
+		See Documentation/wmi/devices/wmi-bmof.rst for details.
diff --git a/Documentation/wmi/devices/index.rst b/Documentation/wmi/devices/index.rst
new file mode 100644
index 000000000000..c08735a9d7df
--- /dev/null
+++ b/Documentation/wmi/devices/index.rst
@@ -0,0 +1,22 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+=============================
+Driver-specific Documentation
+=============================
+
+This section provides information about various devices supported by
+the Linux kernel, their protocols and driver details.
+
+.. toctree::
+   :maxdepth: 1
+   :numbered:
+   :glob:
+
+   *
+
+.. only:: subproject and html
+
+   Indices
+   =======
+
+   * :ref:`genindex`
diff --git a/Documentation/wmi/devices/wmi-bmof.rst b/Documentation/wmi/devices/wmi-bmof.rst
new file mode 100644
index 000000000000..ca1ee9a29be3
--- /dev/null
+++ b/Documentation/wmi/devices/wmi-bmof.rst
@@ -0,0 +1,25 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+==============================
+WMI embedded Binary MOF driver
+==============================
+
+Introduction
+============
+
+Many machines embed WMI Binary MOF (Managed Object Format) metadata used to
+describe the details of their ACPI WMI interfaces. The data can be decoded
+with tools like `bmfdec <https://github.com/pali/bmfdec>`_ to obtain a
+human readable WMI interface description, which is useful for developing
+new WMI drivers.
+
+The Binary MOF data can be retrieved from the ``bmof`` sysfs attribute of the
+associated WMI device. Please note that multiple WMI devices containing Binary
+MOF data can exist on a given system.
+
+WMI interface
+=============
+
+The Binary MOF WMI device is identified by the WMI GUID ``05901221-D566-11D1-B2F0-00A0C9062910``.
+The Binary MOF can be obtained by doing a WMI data block query. The result is
+then returned as an ACPI buffer with a variable size.
diff --git a/Documentation/wmi/index.rst b/Documentation/wmi/index.rst
index b29933a86380..537cff188e14 100644
--- a/Documentation/wmi/index.rst
+++ b/Documentation/wmi/index.rst
@@ -8,6 +8,7 @@ WMI Subsystem
    :maxdepth: 1
 
    acpi-interface
+   devices/index
 
 .. only::  subproject and html
 
diff --git a/MAINTAINERS b/MAINTAINERS
index 46ad203dad12..fcacf0038d11 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22739,6 +22739,13 @@ L:	linux-wireless@vger.kernel.org
 S:	Odd fixes
 F:	drivers/net/wireless/legacy/wl3501*
 
+WMI BINARY MOF DRIVER
+L:	platform-drivers-x86@vger.kernel.org
+S:	Orphan
+F:	Documentation/ABI/stable/sysfs-platform-wmi-bmof
+F:	Documentation/wmi/devices/wmi-bmof.rst
+F:	drivers/platform/x86/wmi-bmof.c
+
 WOLFSON MICROELECTRONICS DRIVERS
 L:	patches@opensource.cirrus.com
 S:	Supported
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 22052031c719..3d5dd9e997a6 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -43,8 +43,8 @@ config WMI_BMOF
 	default ACPI_WMI
 	help
 	  Say Y here if you want to be able to read a firmware-embedded
-	  WMI Binary MOF data. Using this requires userspace tools and may be
-	  rather tedious.
+	  WMI Binary MOF (Managed Object Format) data. Using this requires
+	  userspace tools and may be rather tedious.
 
 	  To compile this driver as a module, choose M here: the module will
 	  be called wmi-bmof.