Mem 2 Mem VPSS-CSC Composite device

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This Design enable Xilinx VPSS-CSC (Colour Space Conversion) to work as Mem 2 Mem Device. Xilinx Frame buffer Read → Xilinx VPSS-CSC → Xilinx Frame buffer write act as composite device

Reference Design

This reference design is with ZCU102

Device tree binding

The dts node should be defined with correct configuration. The common dts properties are described in video.txt

               v_frmbuf_rd_0: v_frmbuf_rd@a0010000 {
                        compatible = "xlnx,axi-frmbuf-rd-v2";
                        #dma-cells = <1>;
                        interrupt-parent = <&gic>;
                        interrupts = <0 90 4>;
                        reg = <0x0 0xa0010000 0x0 0x10000>;
                        reset-gpios = <&gpio 78 1>;
                        xlnx,dma-addr-width = <32>;
                        xlnx,vid-formats = "rgb888", "bgr888", "nv16", "yuyv";
                };
                csc_1:csc@a0100000 {
                        compatible = "xlnx,v-vpss-csc";
                        reg = <0x0 0xa0100000 0x0 0x10000>;
                        clocks = <&vid_stream_clk>;
                        reset-gpios = <&gpio 80 1>;

                        ports {
                                #address-cells = <1>;
                                #size-cells = <0>;
                                port@0 {
                                        reg = <0>;
                                        xlnx,video-format = <2>;
                                        xlnx,video-width = <8>;

                                        csc_in: endpoint {
                                                remote-endpoint = <&rb_out>;
                                        };
                                };
                                port@1 {
                                        reg = <1>;
                                        xlnx,video-format = <2>;
                                        xlnx,video-width = <8>;

                                        csc_out: endpoint {
                                                remote-endpoint = <&wb_in>;
                                        };
                                };
                        };
                };

                v_frmbuf_wr_0: v_frmbuf_wr@a0000000 {
                        compatible = "xlnx,axi-frmbuf-wr-v2";
                        #dma-cells = <1>;
                        interrupt-parent = <&gic>;
                        interrupts = <0 89 4>;
                        reg = <0x0 0xa0000000 0x0 0x10000>;
                        reset-gpios = <&gpio 79 1>;
                        xlnx,dma-addr-width = <32>;
                        xlnx,vid-formats = "rgb888", "bgr888", "nv16", "yuyv";
                };



                video_m2m {
                        compatible = "xlnx,mem2mem";
                        dmas = <&v_frmbuf_rd_0 0>, <&v_frmbuf_wr_0 0>;
                        dma-names = "tx", "rx";
                        ports {
                                #address-cells = <1>;
                                #size-cells = <0>;
                                port@0 {
                                        reg = <0>;
                                        direction = "input";

                                        wb_in: endpoint {
                                                remote-endpoint = <&csc_out>;
                                        };
                                };

                                port@1 {
                                        reg = <1>;
                                        direction = "output";

                                        rb_out: endpoint {
                                                remote-endpoint = <&csc_in>;
                                        };

                                };
                        };

                };

Test Commands:

With above device tree, you will find below media device in linux.

# media-ctl -p
Media controller API version 4.14.0

Media device information
------------------------
driver          xilinx-mem2mem
model           Xilinx Videoi M2M Composite Dev
serial
bus info
hw revision     0x0
driver version  4.14.0

Device topology
- entity 1: xilinx-mem2mem (2 pads, 2 links)
            type Node subtype V4L flags 0
            device node name /dev/video0
        pad0: Sink
                <- "a0100000.csc":1 [ENABLED]
        pad1: Source
                -> "a0100000.csc":0 [ENABLED]

- entity 6: a0100000.csc (2 pads, 2 links)
            type V4L2 subdev subtype Unknown flags 0
            device node name /dev/v4l-subdev0
        pad0: Sink
                [fmt:RBG888_1X24/1280x720 field:none]
                <- "xilinx-mem2mem":1 [ENABLED]
        pad1: Source
                [fmt:RBG888_1X24/1280x720 field:none]
                -> "xilinx-mem2mem":0 [ENABLED]

First configure CSC sink and src pads to required formats.

Below command set CSC Sink pad to 1920X1080 RGB and Src pad to 1920X1080 YUY2.

media-ctl -d /dev/media0 -V "\"a0100000.csc\":0 [fmt:RBG888_1X24/1920x1080 field:none]"
media-ctl -d /dev/media0 -V "\"a0100000.csc\":1 [fmt:UYVY8_1X16/1920x1080 field:none]"

Then fire the GST command. Here 1920X1080 RGB is the input to the v4l2video0convert and the output is 1920X1080 YUY2

gst-launch-1.0 videotestsrc num-buffers=10 ! video/x-raw, width=1920, height=1080, format=RGB ! v4l2video0convert capture-io-mode=4 output-io-mode=4 ! video/x-raw, width=1920, height=1080, format=YUY2 ! filesink location=output.yuy2

Here 1280X720 YUY2 is the input to the v4l2video0convert and the output is 1280X720 RGB

media-ctl -d /dev/media0 -V "\"a0100000.csc\":1 [fmt:RBG888_1X24/1280x720 field:none]"
media-ctl -d /dev/media0 -V "\"a0100000.csc\":0 [fmt:UYVY8_1X16/1280x720 field:none]"

gst-launch-1.0 videotestsrc num-buffers=1 ! video/x-raw, width=1280, height=720, format=YUY2 ! v4l2video0convert capture-io-mode=4 output-io-mode=4 ! video/x-raw, width=1280, height=720, format=RGB ! filesink location=op.rgb