Re: [PATCH v11 1/2] dt-bindings: display/bridge: Add binding for NWL mipi dsi host controller

[Laurent Pinchart]

Hi Guido,

Thank you for the patch.

On Thu, Apr 09, 2020 at 12:42:01PM +0200, Guido GÃnther wrote:
> The Northwest Logic MIPI DSI IP core can be found in NXPs i.MX8 SoCs.
> 
> Signed-off-by: Guido GÃnther <agx@xxxxxxxxxxx>
> Tested-by: Robert Chiras <robert.chiras@xxxxxxx>
> Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
> Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
> Reviewed-by: Fabio Estevam <festevam@xxxxxxxxx>
> ---
>  .../bindings/display/bridge/nwl-dsi.yaml      | 226 ++++++++++++++++++
>  1 file changed, 226 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/nwl-dsi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/nwl-dsi.yaml b/Documentation/devicetree/bindings/display/bridge/nwl-dsi.yaml
> new file mode 100644
> index 000000000000..8aff2d68fc33
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/nwl-dsi.yaml
> @@ -0,0 +1,226 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/bridge/nwl-dsi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Northwest Logic MIPI-DSI controller on i.MX SoCs
> +
> +maintainers:
> +  - Guido GÃnther <agx@xxxxxxxxxxx>
> +  - Robert Chiras <robert.chiras@xxxxxxx>
> +
> +description: |
> +  NWL MIPI-DSI host controller found on i.MX8 platforms. This is a dsi bridge for
> +  the SOCs NWL MIPI-DSI host controller.
> +
> +properties:
> +  compatible:
> +    const: fsl,imx8mq-nwl-dsi
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +  clocks:
> +    items:
> +      - description: DSI core clock
> +      - description: RX_ESC clock (used in escape mode)
> +      - description: TX_ESC clock (used in escape mode)
> +      - description: PHY_REF clock
> +      - description: LCDIF clock
> +
> +  clock-names:
> +    items:
> +      - const: core
> +      - const: rx_esc
> +      - const: tx_esc
> +      - const: phy_ref
> +      - const: lcdif
> +
> +  mux-controls:
> +    description:
> +      mux controller node to use for operating the input mux
> +
> +  phys:
> +    maxItems: 1
> +    description:
> +      A phandle to the phy module representing the DPHY
> +
> +  phy-names:
> +    items:
> +      - const: dphy
> +
> +  power-domains:
> +    maxItems: 1
> +
> +  resets:
> +    items:
> +      - description: dsi byte reset line
> +      - description: dsi dpi reset line
> +      - description: dsi esc reset line
> +      - description: dsi pclk reset line
> +
> +  reset-names:
> +    items:
> +      - const: byte
> +      - const: dpi
> +      - const: esc
> +      - const: pclk
> +
> +  ports:
> +    type: object
> +    description:
> +      A node containing DSI input & output port nodes with endpoint
> +      definitions as documented in
> +      Documentation/devicetree/bindings/graph.txt.
> +    properties:
> +      port@0:
> +        type: object
> +        description:
> +          Input port node to receive pixel data from the
> +          display controller. Exactly one endpoint must be
> +          specified.
> +        properties:
> +          '#address-cells':
> +            const: 1
> +
> +          '#size-cells':
> +            const: 0
> +
> +          endpoint@0:
> +            description: sub-node describing the input from LCDIF
> +            type: object
> +
> +          endpoint@1:
> +            description: sub-node describing the input from DCSS
> +            type: object

This models the two inputs to the IP core, that are connected to a mux
internally, controlled through mux-controls, right ? Why is a single
endpoint supported then, if there are two connections at the hardware
level, and why is this using endpoints instead of ports as there are
really two input ports ?

Apart from that the bindings look ok to me.

> +
> +          reg:
> +            const: 0
> +
> +        required:
> +          - '#address-cells'
> +          - '#size-cells'
> +          - reg
> +
> +        oneOf:
> +          - required:
> +              - endpoint@0
> +          - required:
> +              - endpoint@1
> +
> +        additionalProperties: false
> +
> +      port@1:
> +        type: object
> +        description:
> +          DSI output port node to the panel or the next bridge
> +          in the chain
> +
> +      '#address-cells':
> +        const: 1
> +
> +      '#size-cells':
> +        const: 0
> +
> +    required:
> +      - '#address-cells'
> +      - '#size-cells'
> +      - port@0
> +      - port@1
> +
> +    additionalProperties: false
> +
> +patternProperties:
> +  "^panel@[0-9]+$":
> +    type: object
> +
> +required:
> +  - '#address-cells'
> +  - '#size-cells'
> +  - clock-names
> +  - clocks
> +  - compatible
> +  - interrupts
> +  - mux-controls
> +  - phy-names
> +  - phys
> +  - ports
> +  - reg
> +  - reset-names
> +  - resets
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> +
> +   #include <dt-bindings/clock/imx8mq-clock.h>
> +   #include <dt-bindings/interrupt-controller/arm-gic.h>
> +   #include <dt-bindings/reset/imx8mq-reset.h>
> +
> +   mipi_dsi: mipi_dsi@30a00000 {
> +              #address-cells = <1>;
> +              #size-cells = <0>;
> +              compatible = "fsl,imx8mq-nwl-dsi";
> +              reg = <0x30A00000 0x300>;
> +              clocks = <&clk IMX8MQ_CLK_DSI_CORE>,
> +                       <&clk IMX8MQ_CLK_DSI_AHB>,
> +                       <&clk IMX8MQ_CLK_DSI_IPG_DIV>,
> +                       <&clk IMX8MQ_CLK_DSI_PHY_REF>,
> +                       <&clk IMX8MQ_CLK_LCDIF_PIXEL>;
> +              clock-names = "core", "rx_esc", "tx_esc", "phy_ref", "lcdif";
> +              interrupts = <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>;
> +              mux-controls = <&mux 0>;
> +              power-domains = <&pgc_mipi>;
> +              resets = <&src IMX8MQ_RESET_MIPI_DSI_RESET_BYTE_N>,
> +                       <&src IMX8MQ_RESET_MIPI_DSI_DPI_RESET_N>,
> +                       <&src IMX8MQ_RESET_MIPI_DSI_ESC_RESET_N>,
> +                       <&src IMX8MQ_RESET_MIPI_DSI_PCLK_RESET_N>;
> +              reset-names = "byte", "dpi", "esc", "pclk";
> +              phys = <&dphy>;
> +              phy-names = "dphy";
> +
> +              panel@0 {
> +                      #address-cells = <1>;
> +                      #size-cells = <0>;
> +                      compatible = "rocktech,jh057n00900";
> +                      reg = <0>;
> +                      port@0 {
> +                           reg = <0>;
> +                           panel_in: endpoint {
> +                                     remote-endpoint = <&mipi_dsi_out>;
> +                           };
> +                      };
> +              };
> +
> +              ports {
> +                    #address-cells = <1>;
> +                    #size-cells = <0>;
> +
> +                    port@0 {
> +                           #size-cells = <0>;
> +                           #address-cells = <1>;
> +                           reg = <0>;
> +                           mipi_dsi_in: endpoint@0 {
> +                                        reg = <0>;
> +                                        remote-endpoint = <&lcdif_mipi_dsi>;
> +                           };
> +                    };
> +                    port@1 {
> +                           reg = <1>;
> +                           mipi_dsi_out: endpoint {
> +                                         remote-endpoint = <&panel_in>;
> +                           };
> +                    };
> +              };
> +      };

-- 
Regards,

Laurent Pinchart