On 10/10/2017 10:20 AM, Mauro Carvalho Chehab wrote: > Em Tue, 10 Oct 2017 09:47:13 +0200 > Hans Verkuil <hverkuil@xxxxxxxxx> escreveu: > >> On 09/28/2017 12:23 AM, Mauro Carvalho Chehab wrote: >>> Add a glossary of terms for V4L2, as several concepts are complex >>> enough to cause misunderstandings. >>> >>> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> >>> --- >>> Documentation/media/uapi/v4l/glossary.rst | 136 ++++++++++++++++++++++++++++++ >>> Documentation/media/uapi/v4l/v4l2.rst | 1 + >>> 2 files changed, 137 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..b6767da1a46e >>> --- /dev/null >>> +++ b/Documentation/media/uapi/v4l/glossary.rst >>> @@ -0,0 +1,136 @@ >>> +======== >>> +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 >>> + The same as V4L2 main driver. >> >> Change this to the more standard phrase: >> >> See: V4L2 main driver. >> >>> + >>> + Device Node >>> + A character device node in the file system used to control and do >> >> and -> and/or >> >>> + input/output data transfers from/to a Kernel driver. >>> + >>> + Digital Signal Processor - DSP >>> + A specialized microprocessor, with its architecture optimized for >>> + the operational needs of digital signal processing. >> >> I'd say 'requirements' instead of 'needs'. I think that's a better term. >> >>> + >>> + 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). >>> + >>> + Inter-Integrated Circuit - I²C >>> + A multi-master, multi-slave, packet switched, single-ended, >>> + serial computer bus used to control V4L2 sub-devices. >> >> I'd rephrase this a bit: >> >> A multi-master, multi-slave, packet switched, single-ended, >> serial computer bus. Most V4L2 sub-devices are controlled via >> this bus. >> >> Your text suggested that i2c is used exclusively for V4L2 subdevs, but >> of course it is used for many other devices as well. >> >>> + >>> + 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. >> >> Perhaps add an entry for 'Chip' as well, with a 'See: Integrated circuit' as >> description? Just to be consistent. >> >>> + >>> + 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 >>> + The same as IP core. >> >> 'See: ' >> >>> + >>> + MC-centric >>> + V4L2 hardware that requires a Media controller. >>> + >>> + See :ref:`v4l2_hardware_control`. >>> + >>> + Media Controller >>> + An API designed to expose and control devices and sub-devices >>> + relationships to applications. >> >> This sentence is not clear. I propose this: >> >> An API designed to expose and control the relationships of the Media >> Harware to applications. >> >>> + >>> + See :ref:`media_controller`. >>> + >>> + Media hardware >>> + A group of hardware components that together make a larger >>> + user-facing functional media hardware. For instance the SoC ISP IP >> >> I'd just say "form the functional". The term 'user-facing' is out of place here. >> >>> + cores and external camera sensors together make a >> >> make a -> form the >> >> Possible synonym for 'form': 'constitute'. I'm OK with either. >> >>> + 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 >>> + A hardware used to on a media device supported by the V4L2 >>> + subsystem. >> >> No idea what you mean here. Perhaps this: >> >> 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 >>> + Part of the media hardware that is implemented via a >>> + V4L2 sub-device driver. >> >> When we talk about 'V4L2 sub-device' we talk about a driver that implement >> the subdev kernel API. I suggest that you change 'V4L2 sub-device' to >> 'V4L2 sub-device driver', then explain that such a driver implements support >> for a Hardware component. >> >>> + >>> + See :ref:`subdev`. >>> + >>> + Vdevnode-centric >>> + V4L2 hardware that it is controlled via V4L2 device nodes. >> >> 'that it' -> 'that' >> >> This also needs a reference: >> >> See :ref:`v4l2_hardware_control`. >> >>> + >>> + 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 >>> >>> >>> >> >> Regards, >> >> Hans > > I agree with all proposed changes. I'm folding the attached patch to it. > > Thanks, > Mauro > > diff --git a/Documentation/media/uapi/v4l/glossary.rst b/Documentation/media/uapi/v4l/glossary.rst > index b6767da1a46e..e95820d91bac 100644 > --- a/Documentation/media/uapi/v4l/glossary.rst > +++ b/Documentation/media/uapi/v4l/glossary.rst > @@ -13,15 +13,18 @@ Glossary > .. glossary:: > > Bridge driver > - The same as V4L2 main driver. > + See: V4L2 main driver. > + > + Chip: > + See: Integrated circuit. > > Device Node > - A character device node in the file system used to control and do > - input/output data transfers from/to a Kernel driver. > + 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 needs of digital signal processing. > + the operational requirements of digital signal processing. > > Driver > The part of the Linux Kernel that implements support > @@ -47,7 +50,8 @@ Glossary > > Inter-Integrated Circuit - I²C > A multi-master, multi-slave, packet switched, single-ended, > - serial computer bus used to control V4L2 sub-devices. > + serial computer bus. Most V4L2 sub-device are controlled > + via this bus. > > See http://www.nxp.com/docs/en/user-guide/UM10204.pdf. > > @@ -67,7 +71,7 @@ Glossary > See https://en.wikipedia.org/wiki/Semiconductor_intellectual_property_core). > > IP block > - The same as IP core. > + See: IP core. > > MC-centric > V4L2 hardware that requires a Media controller. > @@ -75,15 +79,15 @@ Glossary > See :ref:`v4l2_hardware_control`. > > Media Controller > - An API designed to expose and control devices and sub-devices > - relationships to applications. > + An API designed to expose and control the relationships of the Media > + Harware to applications. > > See :ref:`media_controller`. > > Media hardware > - A group of hardware components that together make a larger > - user-facing functional media hardware. For instance the SoC ISP IP > - cores and external camera sensors together make a > + 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 > @@ -113,8 +117,10 @@ Glossary > as specified in :ref:`v4l2_device_naming`. > > V4L2 hardware > - A hardware used to on a media device supported by the V4L2 > - subsystem. > + 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 > @@ -125,12 +131,15 @@ Glossary > See :ref:`v4l2_hardware_control`. > > V4L2 sub-device > - Part of the media hardware that is implemented via a > - V4L2 sub-device driver. > + See: :ref:`V4L2 sub-device driver` > + > + V4L2 sub-device driver > + Part of the media hardware that implements support for > + a hardware component. The description now no longer fits the term. I suggest: "The V4L2 driver that implements support for a hardware component." Otherwise this looks good. Regards, Hans > > See :ref:`subdev`. > > Vdevnode-centric > - V4L2 hardware that it is controlled via V4L2 device nodes. > + V4L2 hardware that is controlled via V4L2 device nodes. > > See :ref:`v4l2_hardware_control`. > >
