Hi Hans and Chris, On Monday 01 December 2014 22:13:38 Laurent Pinchart wrote: > Xilinx platforms have no hardwired video capture or video processing > interface. Users create capture and memory to memory processing > pipelines in the FPGA fabric to suit their particular needs, by > instantiating video IP cores from a large library. > > The Xilinx Video IP core is a framework that models a video pipeline > described in the device tree and expose the pipeline to userspace > through the media controller and V4L2 APIs. > > Signed-off-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com> > Signed-off-by: Hyun Kwon <hyun.k...@xilinx.com> > Signed-off-by: Radhey Shyam Pandey <radh...@xilinx.com> > Signed-off-by: Michal Simek <michal.si...@xilinx.com>
[snip] > diff --git a/Documentation/devicetree/bindings/media/xilinx/video.txt > b/Documentation/devicetree/bindings/media/xilinx/video.txt new file mode > 100644 > index 0000000..15720e4 > --- /dev/null > +++ b/Documentation/devicetree/bindings/media/xilinx/video.txt > @@ -0,0 +1,52 @@ > +DT bindings for Xilinx video IP cores > +------------------------------------- > + > +Xilinx video IP cores process video streams by acting as video sinks and/or > +sources. They are connected by links through their input and output ports, > +creating a video pipeline. > + > +Each video IP core is represented by an AMBA bus child node in the device > +tree using bindings documented in this directory. Connections between the > IP > +cores are represented as defined in ../video-interfaces.txt. > + > +The whole pipeline is represented by an AMBA bus child node in the device > +tree using bindings documented in ./xlnx,video.txt. > + > +Common properties > +----------------- > + > +The following properties are common to all Xilinx video IP cores. > + > +- xlnx,video-format: This property represents a video format transmitted on > an > + AXI bus between video IP cores. How the format relates to the IP core is > + decribed in the IP core bindings documentation. The following formats are > + supported. > + > + rbg > + xrgb > + yuv422 > + yuv444 > + rggb > + grbg > + gbrg > + bggr > + > +- xlnx,video-width: This property qualifies the video format with the > sample > + width expressed as a number of bits per pixel component. All components > must > + use the same width. Hans, last time we've discussed this on IRC you were not happy with the format description used in these DT bindings. Your argument was, if I remember correctly, that as the formats map directly to media bus codes, it would be better to use the media bus codes (or a string representation of them) in the bindings instead of creating a new format description. Is that correct ? Chris, what's your opinion on that ? The RGB and YUV formats in the table below describe the hardware and come from table 1-4 on page 8 of http://www.xilinx.com/support/documentation/ip_documentation/axi_videoip/v1_0/ug934_axi_videoIP.pdf. The Bayer formats are not standardized in the document, and I don't think we need them at the moment. > +The following table lists the supported formats and widths combinations, > along > +with the corresponding media bus pixel code. > + > +----------------+-------+-------------------------------------------------- > +Format | Width | Media bus code > +----------------+-------+-------------------------------------------------- > +rbg | 8 | V4L2_MBUS_FMT_RBG888_1X24 > +xrgb | 8 | V4L2_MBUS_FMT_RGB888_1X32_PADHI > +yuv422 | 8 | V4L2_MBUS_FMT_UYVY8_1X16 > +yuv444 | 8 | V4L2_MBUS_FMT_VUY888_1X24 > +rggb | 8 | V4L2_MBUS_FMT_SRGGB8_1X8 > +grbg | 8 | V4L2_MBUS_FMT_SGRBG8_1X8 > +gbrg | 8 | V4L2_MBUS_FMT_SGBRG8_1X8 > +bggr | 8 | V4L2_MBUS_FMT_SBGGR8_1X8 > +----------------+-------+-------------------------------------------------- > diff --git > a/Documentation/devicetree/bindings/media/xilinx/xlnx,video.txt > b/Documentation/devicetree/bindings/media/xilinx/xlnx,video.txt new file > mode 100644 > index 0000000..5a02270 > --- /dev/null > +++ b/Documentation/devicetree/bindings/media/xilinx/xlnx,video.txt > @@ -0,0 +1,55 @@ > +Xilinx Video IP Pipeline (VIPP) > +------------------------------- > + > +General concept > +--------------- > + > +Xilinx video IP pipeline processes video streams through one or more Xilinx > +video IP cores. Each video IP core is represented as documented in > video.txt > +and IP core specific documentation, xlnx,v-*.txt, in this directory. The DT > +node of the VIPP represents as a top level node of the pipeline and defines > +mappings between DMAs and the video IP cores. > + > +Required properties: > + > +- compatible: Must be "xlnx,video". > + > +- dmas, dma-names: List of one DMA specifier and identifier string (as > defined > + in Documentation/devicetree/bindings/dma/dma.txt) per port. Each port > + requires a DMA channel with the identifier string set to "port" followed > by > + the port index. > + > +- ports: Video port, using the DT bindings defined in > ../video-interfaces.txt. > + > +Required port properties: > + > +- direction: should be either "input" or "output" depending on the > direction > + of stream. > + > +Example: > + > + video_cap { > + compatible = "xlnx,video"; > + dmas = <&vdma_1 1>, <&vdma_3 1>; > + dma-names = "port0", "port1"; > + > + ports { > + #address-cells = <1>; > + #size-cells = <0>; > + > + port@0 { > + reg = <0>; > + direction = "input"; > + vcap0_in0: endpoint { > + remote-endpoint = <&scaler0_out>; > + }; > + }; > + port@1 { > + reg = <1>; > + direction = "input"; > + vcap0_in1: endpoint { > + remote-endpoint = <&switch_out1>; > + }; > + }; > + }; > + }; -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
