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 | 150 ++++++++++++++++++++++++++++++ Documentation/media/uapi/v4l/v4l2.rst | 1 + 2 files changed, 151 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..08980e9cb98e --- /dev/null +++ b/Documentation/media/uapi/v4l/glossary.rst @@ -0,0 +1,150 @@ +======== +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 media hardware. Often, the + bridge driver is the same as V4L2 main driver. + + Chip: + See: Integrated circuit. + + 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 microprocessor, with its architecture optimized for + the operational requirements of digital signal processing. + + Driver + The part of the Linux Kernel that implements support + for a hardware component. + + Field-programmable Gate Array - FPGA + A field-programmable gate array (FPGA) is an 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 media hardware. For example an I²C or SPI device, + or an IP block inside an SoC or FPGA. + + Image Signal Processor - ISP + A specialised processor 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 V4L2 main driver. + + Inter-Integrated Circuit - I²C + A multi-master, multi-slave, packet switched, single-ended, + serial computer bus. Most V4L2 sub-devices are controlled + via this bus. + + See http://www.nxp.com/docs/en/user-guide/UM10204.pdf. + + Integrated circuit - IC + A set of electronic circuits on one small flat piece of + semiconductor material, normally silicon. + + Also known as 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). + + IP block + See: IP core. + + Media Controller + An API designed to expose and control the relationships of the Media + Harware to applications. + + See :ref:`media_controller`. + + Media Controller centric - MC-centric + V4L2 hardware that requires a Media controller. + + See :ref:`v4l2_hardware_control`. + + Media hardware + A group of hardware components that together form the + functional media hardware. For instance the SoC ISP IP + cores and external camera sensors together form the + camera media hardware. + + Media hardware control + Type of control for a media hardware supported by V4L2 drivers. + + 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 integrated circuit. + + SMBus + A subset of I²C, with defines a stricter usage of the bus. + + Serial Peripheral Interface Bus - SPI + Synchronous serial communication interface specification used for + short distance communication, primarily in embedded systems. + + System on a Chip - SoC + An integrated circuit that integrates all components of a computer + or other electronic systems. + + V4L2 device node + A device node that is associated to a V4L2 main driver, + as specified in :ref:`v4l2_device_naming`. + + V4L2 hardware + Hardware that is controlled by a V4L2 main driver or a V4L2 + sub-device driver. V4L2 hardware is a subset of the + Media hardware. Often the two are the same, but Media hardware + can also contain other non-V4L2 hardware such as DVB hardware. + + V4L2 main driver + The V4L2 device driver that implements the main logic to talk with + the V4L2 hardware. + + Also known as bridge driver. + + See :ref:`v4l2_hardware_control`. + + V4L2 sub-device + See: :ref:`V4L2 sub-device driver` + + V4L2 sub-device driver + A driver for a media component whose bus(es) connects it + to the hardware controlled via the V4L2 main driver. + + See :ref:`subdev`. + + Video device node centric - Vdevnode-centric + V4L2 hardware that is controlled via V4L2 device nodes. + + 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
