media/v4l/dev-subdev.rst

18 and discover the hardware topology using the media entities, pads and
30 -  negotiate image formats on individual pads
32 -  inspect and modify internal data routing between pads of the same entity
133 whole pipeline and making sure that connected pads have compatible
147 Acceptable formats on pads can (and usually do) depend on a number of
148 external parameters, such as formats on other pads, active links, or
149 even controls. Finding a combination of formats on all pads in a video
182 (as long as external parameters, such as formats on other pads or links'
186 or active format is set on a pad, corresponding formats on other pads of
191 -  Formats should be propagated from sink pads to source pads. Modifying
196    reset the scale factors to default values when sink pads formats are
198    source pads formats should be reset to the sink pads formats.
309    host frontend and scaler sink and source pads have the default
342 Many sub-devices support cropping frames on their input or output pads
356 On sink pads, cropping is applied relative to the current pad format.
375 On source pads, cropping is similar to sink pads, with the exception
377 COMPOSE rectangle on the sink pad. In both sink and source pads, the
482 and finally cropping for two source pads individually from the resulting
497 The subdev driver supports two sink pads and two source pads. The images
498 from both of the sink pads are individually cropped, then scaled and
501 source pads.
509 Streams, multiplexed media pads and internal routing
527 pads.
541 tables which describe how the incoming streams from sink pads are routed to the
542 source pads.
558 formats and selections from pads to (pad, stream) pairs. Besides the
563 Instead of the sub-device wide merging of streams from all sink pads
564 towards all source pads, data flows for each route are separate from each
565 other. Any number of routes from streams on sink pads towards streams on
566 source pads is allowed, to the extent supported by drivers. For every
582 1. Set up links. Connect the pads between sub-devices using the
593    associated with either sink or source pads of routes configured using the
604 - Multiplexer bridge (Bridge). The bridge has two sink pads, connected to the
605   sensors (pads 0, 1), and one source pad (pad 2), which outputs two streams.
608   connected to the bridge, and two source pads (pads 1-2), going to the DMA
609   engine. The receiver demultiplexes the incoming streams to the source pads.