Re: [PATCH v6 5/8] dt-bindings: display: add i.MX6 MIPI DSI host controller doc

From: Laurent Pinchart
Date: Tue Apr 14 2020 - 16:42:38 EST


Hi Adrian,

Thank you for the patch.

On Tue, Apr 14, 2020 at 06:19:52PM +0300, Adrian Ratiu wrote:
> This provides an example DT binding for the MIPI DSI host controller
> present on the i.MX6 SoC based on Synopsis DesignWare v1.01 IP.
>
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Cc: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> Cc: Fabio Estevam <festevam@xxxxxxxxx>
> Cc: devicetree@xxxxxxxxxxxxxxx
> Tested-by: Adrian Pop <pop.adrian61@xxxxxxxxx>
> Tested-by: Arnaud Ferraris <arnaud.ferraris@xxxxxxxxxxxxx>
> Signed-off-by: Sjoerd Simons <sjoerd.simons@xxxxxxxxxxxxx>
> Signed-off-by: Martyn Welch <martyn.welch@xxxxxxxxxxxxx>
> Signed-off-by: Adrian Ratiu <adrian.ratiu@xxxxxxxxxxxxx>
> ---
> Changes since v5:
> - Fixed missing reg warning (Fabio)
> - Updated dt-schema and fixed warnings (Rob)
>
> Changes since v4:
> - Fixed yaml binding to pass `make dt_binding_check dtbs_check`
> and addressed received binding feedback (Rob)
>
> Changes since v3:
> - Added commit message (Neil)
> - Converted to yaml format (Neil)
> - Minor dt node + driver fixes (Rob)
> - Added small panel example to the host controller binding
>
> Changes since v2:
> - Fixed commit tags (Emil)
> ---
> .../display/imx/fsl,mipi-dsi-imx6.yaml | 139 ++++++++++++++++++
> 1 file changed, 139 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/display/imx/fsl,mipi-dsi-imx6.yaml
>
> diff --git a/Documentation/devicetree/bindings/display/imx/fsl,mipi-dsi-imx6.yaml b/Documentation/devicetree/bindings/display/imx/fsl,mipi-dsi-imx6.yaml
> new file mode 100644
> index 000000000000..10e289ea219a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/imx/fsl,mipi-dsi-imx6.yaml
> @@ -0,0 +1,139 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/imx/fsl,mipi-dsi-imx6.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Freescale i.MX6 DW MIPI DSI Host Controller
> +
> +maintainers:
> + - Adrian Ratiu <adrian.ratiu@xxxxxxxxxxxxx>
> +
> +description: |
> + The i.MX6 DSI host controller is a Synopsys DesignWare MIPI DSI v1.01
> + IP block with a companion PHY IP.
> +
> + These DT bindings follow the Synopsys DW MIPI DSI bindings defined in
> + Documentation/devicetree/bindings/display/bridge/dw_mipi_dsi.txt with
> + the following device-specific properties.

Not necessarily a prerequisite for this patch, but it would be nice to
get that converted to yaml, and included here with

allOf:
$ref: ../bridge/snps,dw-mipi-dsi.yaml#

(assuming that's how the file will be called).

> +
> +properties:
> + compatible:
> + items:
> + - const: fsl,imx6q-mipi-dsi
> + - const: snps,dw-mipi-dsi
> +
> + reg:
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
> +
> + clocks:
> + items:
> + - description: Module Clock
> + - description: DSI bus clock
> +
> + clock-names:
> + items:
> + - const: ref
> + - const: pclk
> +
> + fsl,gpr:
> + description: Phandle to the iomuxc-gpr region containing the multiplexer control register.

Could you please wrap liens at a 80 columns boundary ?

> + $ref: /schemas/types.yaml#/definitions/phandle
> +
> + ports:
> + type: object
> + description: |
> + A node containing DSI input & output port nodes with endpoint
> + definitions as documented in
> + Documentation/devicetree/bindings/media/video-interfaces.txt
> + Documentation/devicetree/bindings/graph.txt
> + properties:

You should add

'#address-cells':
const: 1

'#size-cells':
const: 0

> + port@0:
> + type: object
> + description:
> + DSI input port node, connected to the ltdc rgb output port.
> +
> + port@1:
> + type: object
> + description:
> + DSI output port node, connected to a panel or a bridge input port"


Should this be "RGB output port node" ? And s/"/./

And here you should add

additionalProperties: false

> +
> +patternProperties:
> + "^panel@[0-3]$":
> + type: object
> + description: |
> + A node containing the panel or bridge description as documented in
> + Documentation/devicetree/bindings/display/mipi-dsi-bus.txt
> + properties:
> + port:
> + type: object
> + description:
> + Panel or bridge port node, connected to the DSI output port (port@1)

Does this belong here ? I think the port property for the panel needs to
be described in the panel's binding instead.

> +
> + "#address-cells":
> + const: 1
> +
> + "#size-cells":
> + const: 0

These two properties are not pattern properties, right ? Should they be
listed under the properties above ?

> +
> +required:
> + - "#address-cells"
> + - "#size-cells"
> + - compatible
> + - reg
> + - interrupts
> + - clocks
> + - clock-names
> + - ports
> +
> +additionalProperties: false
> +
> +examples:
> + - |+
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + #include <dt-bindings/clock/imx6qdl-clock.h>
> + #include <dt-bindings/gpio/gpio.h>

Alphabetical order ?

> +
> + dsi: dsi@21e0000 {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + compatible = "fsl,imx6q-mipi-dsi", "snps,dw-mipi-dsi";
> + reg = <0x021e0000 0x4000>;
> + interrupts = <0 102 IRQ_TYPE_LEVEL_HIGH>;
> + fsl,gpr = <&gpr>;
> + clocks = <&clks IMX6QDL_CLK_MIPI_CORE_CFG>,
> + <&clks IMX6QDL_CLK_MIPI_IPG>;
> + clock-names = "ref", "pclk";
> +
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + port@1 {
> + reg = <1>;
> + dsi_out: endpoint {
> + remote-endpoint = <&panel_in>;
> + };
> + };
> + };
> +
> + panel@0 {
> + compatible = "sharp,ls032b3sx01";
> + reg = <0>;
> + reset-gpios = <&gpio6 8 GPIO_ACTIVE_LOW>;
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + port@0 {
> + reg = <0>;
> + panel_in: endpoint {
> + remote-endpoint = <&dsi_out>;
> + };
> + };
> + };
> + };
> + };
> +
> +...

--
Regards,

Laurent Pinchart