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@xxxxxxxxxx> --- .../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 diff --git a/Documentation/userspace-api/media/glossary.rst b/Documentation/userspace-api/media/glossary.rst new file mode 100644 index 000000000000..54451553311c --- /dev/null +++ b/Documentation/userspace-api/media/glossary.rst @@ -0,0 +1,216 @@ +.. 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. diff --git a/Documentation/userspace-api/media/index.rst b/Documentation/userspace-api/media/index.rst index 70a3f3d73698..7f42f83b9f59 100644 --- a/Documentation/userspace-api/media/index.rst +++ b/Documentation/userspace-api/media/index.rst @@ -35,6 +35,9 @@ Please see: mediactl/media-controller cec/cec-api gen-errors + + glossary + fdl-appendix drivers/index -- 2.26.2
