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+.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-or-later
+
+.. For GPL-2.0, see LICENSES/preferred/GPL-2.0
+..
+.. For GFDL-1.1-or-later, see:
+..
+.. Permission is granted to copy, distribute and/or modify this document
+.. under the terms of the GNU Free Documentation License, Version 1.1 or
+.. any later version published by the Free Software Foundation, with no
+.. Invariant Sections, no Front-Cover Texts and no Back-Cover Texts.
+.. A copy of the license is included at
+.. Documentation/userspace-api/media/fdl-appendix.rst.
+
+========
+Glossary
+========
+
+.. note::
+
+ The goal of this section is to standardize the terms used within the media
+ userspace API documentation. This is Work In Progress.
+
+.. Please keep the glossary entries in alphabetical order
+
+.. glossary::
+
+ Bridge Driver
+ A :term:`device driver` that implements the main logic to talk with
+ media hardware.
+
+ CEC API
+ **Consumer Electronics Control API**
+
+ An API designed to receive and transmit data via an HDMI
+ CEC interface.
+
+ See :ref:`cec`.
+
+ Device Driver
+ Part of the Linux Kernel that implements support for a hardware
+ component.
+
+ Device Node
+ A character device node in the file system used to control and
+ transfer data in and out of a Kernel driver.
+
+ Digital TV API
+ **Previously known as DVB API**
+
+ An API designed to control a subset of the :term:`Media Hardware`
+ that implements digital TV (e. g. DVB, ATSC, ISDB, etc).
+
+ See :ref:`dvbapi`.
+
+ DSP
+ **Digital Signal Processor**
+
+ A specialized :term:`Microprocessor`, with its architecture
+ optimized for the operational needs of digital signal processing.
+
+ FPGA
+ **Field-programmable Gate Array**
+
+ An :term:`IC` circuit designed to be configured by a customer or
+ a designer after manufacturing.
+
+ See https://en.wikipedia.org/wiki/Field-programmable_gate_array.
+
+ Hardware Component
+ A subset of the :term:`media hardware`. For example an :term:`I²C` or
+ :term:`SPI` device, or an :term:`IP block` inside an
+ :term:`SoC` or :term:`FPGA`.
+
+ Hardware Peripheral
+ A group of :term:`hardware components <hardware component>` that
+ together make a larger user-facing functional peripheral. For
+ instance, the :term:`SoC` :term:`ISP` :term:`IP block <ip block>`
+ and the external camera sensors together make a camera hardware
+ peripheral.
+
+ Also known as :term:`peripheral`.
+
+ I²C
+ **Inter-Integrated Circuit**
+
+ A multi-master, multi-slave, packet switched, single-ended,
+ serial computer bus used to control some hardware components
+ like sub-device hardware components.
+
+ See http://www.nxp.com/docs/en/user-guide/UM10204.pdf.
+
+ IC
+ **Integrated circuit**
+
+ A set of electronic circuits on one small flat piece of
+ semiconductor material, normally silicon.
+
+ Also known as chip.
+
+ IP Block
+ **Intellectual property core**
+
+ In electronic design a semiconductor intellectual property core,
+ is a reusable unit of logic, cell, or integrated circuit layout
+ design that is the intellectual property of one party.
+ IP Blocks may be licensed to another party or can be owned
+ and used by a single party alone.
+
+ See https://en.wikipedia.org/wiki/Semiconductor_intellectual_property_core).
+
+ ISP
+ **Image Signal Processor**
+
+ A specialized processor that implements a set of algorithms for
+ processing image data. ISPs may implement algorithms for lens
+ shading correction, demosaicing, scaling and pixel format conversion
+ as well as produce statistics for the use of the control
+ algorithms (e.g. automatic exposure, white balance and focus).
+
+ Media API
+ A set of userspace APIs used to control the media hardware. It is
+ composed by:
+
+ - :term:`CEC API`;
+ - :term:`Digital TV API`;
+ - :term:`MC API`;
+ - :term:`RC API`; and
+ - :term:`V4L2 API`.
+
+ See :doc:`index`.
+
+ MC API
+ **Media Controller API**
+
+ An API designed to expose and control the relationships between
+ multimedia devices and sub-devices.
+
+ See :ref:`media_controller`.
+
+ MC-centric
+ :term:`V4L2 hardware` device driver that requires :term:`MC API`.
+
+ Such drivers have ``V4L2_CAP_IO_MC`` device_caps field set
+ (see :ref:`VIDIOC_QUERYCAP`).
+
+ See :ref:`v4l2_hardware_control` for more details.
+
+ Media Hardware
+ Subset of the hardware that is supported by the Linux Media API.
+
+ This includes audio and video capture and playback hardware,
+ digital and analog TV, camera sensors, ISPs, remote controllers,
+ codecs, HDMI Consumer Electronics Control, HDMI capture, etc.
+
+ Microprocessor
+ Electronic circuitry that carries out the instructions of a
+ computer program by performing the basic arithmetic, logical,
+ control and input/output (I/O) operations specified by the
+ instructions on a single integrated circuit.
+
+ Peripheral
+ The same as :term:`hardware peripheral`.
+
+ RC API
+ **Remote Controller API**
+
+ An API designed to receive and transmit data from remote
+ controllers.
+
+ See :ref:`remote_controllers`.
+
+ SMBus
+ A subset of I²C, which defines a stricter usage of the bus.
+
+ SPI
+ **Serial Peripheral Interface Bus**
+
+ Synchronous serial communication interface specification used for
+ short distance communication, primarily in embedded systems.
+
+ SoC
+ **System on a Chip**
+
+ An integrated circuit that integrates all components of a computer
+ or other electronic systems.
+
+ V4L2 API
+ **V4L2 userspace API**
+
+ The userspace API defined in :ref:`v4l2spec`, which is used to
+ control a V4L2 hardware.
+
+ V4L2 Device Node
+ A :term:`device node` that is associated to a V4L driver.
+
+ The V4L2 device node naming is specified at :ref:`v4l2_device_naming`.
+
+ V4L2 Hardware
+ Part of the media hardware which is supported by the :term:`V4L2 API`.
+
+ V4L2 Sub-device
+ V4L2 hardware components that aren't controlled by a
+ :term:`bridge driver`. See :ref:`subdev`.
+
+ Video-node-centric
+ V4L2 device driver that doesn't require a media controller to be used.
+
+ Such drivers have the ``V4L2_CAP_IO_MC`` device_caps field unset
+ (see :ref:`VIDIOC_QUERYCAP`).
+
+ V4L2 Sub-device API
+ Part of the :term:`V4L2 API` which control
+ :term:`V4L2 sub-devices <V4L2 Sub-device>`, like sensors,
+ HDMI receivers, scalers, deinterlacers.
+
+ See :ref:`v4l2_hardware_control` for more details.
@@ -35,6 +35,9 @@ Please see:
mediactl/media-controller
cec/cec-api
gen-errors
+
+ glossary
+
fdl-appendix
drivers/index
Add a glossary of terms used within the media userspace API documentation, as several concepts are complex enough to cause misunderstandings. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> --- .../userspace-api/media/glossary.rst | 216 ++++++++++++++++++ Documentation/userspace-api/media/index.rst | 3 + 2 files changed, 219 insertions(+) create mode 100644 Documentation/userspace-api/media/glossary.rst