Add a glossary of terms for V4L2, as several concepts are complex enough to cause misunderstandings.
Signed-off-by: Mauro Carvalho Chehab <mche...@s-opensource.com> --- Documentation/media/uapi/v4l/glossary.rst | 167 ++++++++++++++++++++++++++++++ Documentation/media/uapi/v4l/v4l2.rst | 1 + 2 files changed, 168 insertions(+) create mode 100644 Documentation/media/uapi/v4l/glossary.rst diff --git a/Documentation/media/uapi/v4l/glossary.rst b/Documentation/media/uapi/v4l/glossary.rst new file mode 100644 index 000000000000..a5a832b4dda5 --- /dev/null +++ b/Documentation/media/uapi/v4l/glossary.rst @@ -0,0 +1,167 @@ +======== +Glossary +======== + +.. note:: + + This goal of section is to standardize the terms used within the V4L2 + documentation. It is written incrementally as they are standardized in + the V4L2 documentation. So, it is a Work In Progress. + +.. Please keep the glossary entries in alphabetical order + +.. glossary:: + + Bridge driver + A driver that provides a bridge between the CPU's bus to the + data and control buses of a :term:`media hardware`. Often, the + bridge driver is the same as :term:`V4L2 main driver`. + + Chip + :See: :term:`Integrated circuit`. + + Device Driver + Driver + The part of the Linux Kernel that implements support + for a :term:`hardware component`. + + Device Node + A character device node in the file system used to control and/or + do input/output data transfers from/to a Kernel driver. + + Digital Signal Processor + DSP + A specialized :term:`microprocessor`, with its architecture optimized + for the operational requirements of digital signal processing. + + Field-programmable Gate Array + FPGA + A field-programmable gate array (FPGA) is an :term:`integrated 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`. + + Image Signal Processor + ISP + A specialized :term:`microprocessor` that implements a set of + algorithms for processing image data. ISPs may implement algorithms + for lens shading correction, demosaic, 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). + + ISP drivers often contain a receiver for image data from external + sources such as sensors and act as :term:`V4L2 main driver`. + + Integrated circuit + IC + A set of electronic circuits on one small flat piece of + semiconductor material, normally silicon. + + Also known as :term:`chip`. + + Intellectual property core + IP 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 cores 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). + + Inter-Integrated Circuit + I²C + A multi-master, multi-slave, packet switched, single-ended, + serial computer bus. A :term:`V4L2 sub-device driver` usually is + controlled via this bus. + + :See: http://www.nxp.com/docs/en/user-guide/UM10204.pdf. + + IP block + :See: :term:`IP core`. + + Media controller + MC + An API designed to expose and control the relationships of the + :term:`media hardware` to applications. + + :See: :ref:`media_controller`. + + Media controller centric + MC-centric + :term:`V4L2 hardware` that requires a :term:`media controller`. + + :See: :ref:`v4l2_hardware_control`. + + Media hardware + A group of hardware components that together form the + functional media hardware. For instance the :term:`SoC` + :term:`ISP` :term:`IP cores <ip core>` and external camera + sensors together form the camera media hardware. + + Media hardware control + Type of control for a :term:`media hardware` supported a + V4L2 :term:`driver`. + + :See: :ref:`v4l2_hardware_control`. + + Microprocessor + An 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 :term:`integrated circuit`. + + SMBus + A subset of :term:`I²C`, with defines a stricter usage of the bus. + + Serial Peripheral Interface + SPI + Synchronous serial communication interface specification used for + short distance communication, primarily in embedded systems. + + System on a Chip + SoC + An :term:`integrated circuit` that integrates all components of a + computer or other electronic systems. + + V4L2 device node + A :term:`device node` that is associated to a + :term:`V4L2 main driver`, as specified in :ref:`v4l2_device_naming`. + + V4L2 hardware + Hardware that is controlled by a :term:`V4L2 main driver` or a + :term:`V4L2 sub-device driver`. V4L2 hardware is a subset of the + :term:`media hardware`. Often the two are the same, but + :term:`media hardware` can also contain other non-V4L2 hardware + such as Digital TV hardware. + + V4L2 main driver + The V4L2 :term:`device driver` that implements the main logic to + talk with the :term:`V4L2 hardware`. + + Often, the same as :term:`bridge driver`. + + :See: :ref:`v4l2_hardware_control`. + + V4L2 sub-device + :See: :term:`V4L2 sub-device driver`. + + V4L2 sub-device driver + A :term:`driver` for a :term:`media hardware` whose bus(es) + connects it to the hardware controlled via the + :term:`V4L2 main driver`. + + :See: :ref:`subdev`. + + Video device node centric + Vdevnode-centric + :term:`V4L2 hardware` that is controlled via + :term:`V4L2 device nodes <v4l2 device node>`. + + :See: :ref:`v4l2_hardware_control`. diff --git a/Documentation/media/uapi/v4l/v4l2.rst b/Documentation/media/uapi/v4l/v4l2.rst index 2128717299b3..698c060939f0 100644 --- a/Documentation/media/uapi/v4l/v4l2.rst +++ b/Documentation/media/uapi/v4l/v4l2.rst @@ -32,6 +32,7 @@ This part describes the Video for Linux API version 2 (V4L2 API) specification. videodev capture-example v4l2grab-example + glossary biblio -- 2.13.6
