Hi Hyun,
Thank you for the patch.
On Sat, Jul 07, 2018 at 07:05:35PM -0700, Hyun Kwon wrote:
> This add a dt binding for ZynqMP DP subsystem.
>
> Signed-off-by: Hyun Kwon <hyun.kwon@xxxxxxxxxx>
> Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
> ---
> v6
> - Add more descriptions and references
> - Remove the description for child node
> v4
> - Specify phy related descriptions
> - Specify dma related descriptions
> - Remove ports
> - Remove child nodes for layers
> - Update the example accordingly
> v2
> - Group multiple ports under 'ports'
> - Replace linux specific terms with generic hardware descriptions
> ---
> ---
> .../bindings/display/xlnx/xlnx,zynqmp-dpsub.txt | 77 ++++++++++++++++++++++
> 1 file changed, 77 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/display/xlnx/xlnx,zynqmp-dpsub.txt
>
> diff --git a/Documentation/devicetree/bindings/display/xlnx/xlnx,zynqmp-dpsub.txt b/Documentation/devicetree/bindings/display/xlnx/xlnx,zynqmp-dpsub.txt
> new file mode 100644
> index 0000000..ec8a58a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/xlnx/xlnx,zynqmp-dpsub.txt
> @@ -0,0 +1,77 @@
> +Xilinx ZynqMP DisplayPort subsystem
> +-----------------------------------
> +
> +The DisplayPort subsystem of Xilinx ZynqMP (Zynq UltraScale+ MPSoC) implements
> +the display and audio pipelines based on the DisplayPort v1.2 standard.
> +The subsystem includes multiple functional blocks as below:
> +
> + buffer manager <-> blender & mixer <-> DP Tx
Shouldn't it be -> instead of <-> ? I assume the data flow is from buffer to
the DP Tx.
> +
> +The buffer manager interacts with external interface such as DMA engines or
> +live streams. The blender and mixer blends the incoming video / audio streams
> +into single stream. The DP Tx converts and transmits the stream into DisplayPort
> +protocol through external phy. The subsystem supports 2 video and 2 audio
> +streams, and various pixel formats / depths up to 4K@30 resolution.
> +
> +Please refer to "Zynq UltraScale+ Device Technical Reference Manual" [UG1085]
> +for more details.
> +
> +Required properties:
> +
> +- compatible: Must be "xlnx,zynqmp-dpsub-1.7".
> +
> +- reg: Physical base address and length of the registers set for the device.
Nitpicking, I'd write "registers sets" as there are four of them according to
reg-names.
> +- reg-names: Must be "dp", "blend", "av_buf", and "aud" to map logical register
> + partitions.
> +
> +- interrupts: Interrupt number.
> +- interrupts-parent: phandle for interrupt controller.
> +
> +- clocks: phandles for axi, audio, non-live video, and live video clocks.
> + axi clock is required. Audio clock is optional. If not present, audio will
> + be disabled. One of non-live or live video clock should be present.
> +- clock-names: The identification strings are required. "aclk" for axi clock.
> + "dp_aud_clk" for audio clock. "dp_vtc_pixel_clk_in" for non-live video clock.
> + "dp_live_video_in_clk" for live video clock (clock from programmable logic).
> +
> +- phys: phandles for phy specifier. The number of lanes is configurable
> + between 1 and 2. The number of phandles should be 1 or 2.
> +- phy-names: The identifier strings. "dp-phy" followed by index, 0 or 1.
> + For single lane, only "dp-phy0" is required. For dual lane, both "dp-phy0"
> + and "dp-phy1" are required where "dp-phy0" is the primary lane.
> +
> +- power-domains: phandle for the corresponding power domain
> +
> +- dmas: phandles for DMA channels as defined in
> + Documentation/devicetree/bindings/dma/dma.txt.
> +- dma-names: The identifier strings are required. "gfx0" for graphics layer
> + dma channel. "vid" followed by index (0 - 2) for video layer dma channels.
You mention above that the blender support two video streams, but you define
four possible DMA engines. How does this work ?
> +
> +Example:
> + zynqmp-display-subsystem@fd4a0000 {
> + compatible = "xlnx,zynqmp-dpsub-1.7";
> + reg = <0x0 0xfd4a0000 0x0 0x1000>,
> + <0x0 0xfd4aa000 0x0 0x1000>,
> + <0x0 0xfd4ab000 0x0 0x1000>,
> + <0x0 0xfd4ac000 0x0 0x1000>;
> + reg-names = "dp", "blend", "av_buf", "aud";
> + interrupts = <0 119 4>;
> + interrupt-parent = <&gic>;
> +
> + clock-names = "dp_apb_clk", "dp_aud_clk", "dp_live_video_in_clk";
> + clocks = <&dp_aclk>, <&clkc 17>, <&si570_1>;
> +
> + phys = <&lane1>, <&lane0>;
> + phy-names = "dp-phy0", "dp-phy1";
> +
> + power-domains = <&pd_dp>;
> +
> + dma-names = "vid0", "vid1", "vid2", "gfx0";
> + dmas = <&xlnx_dpdma 0>,
> + <&xlnx_dpdma 1>,
> + <&xlnx_dpdma 2>,
> + <&xlnx_dpdma 3>;
> + };
> +};
> +
> +[UG1085] https://www.xilinx.com/support/documentation/user_guides/ug1085-zynq-ultrascale-trm.pdf
--
Regards,
Laurent Pinchart
