Re: [PATCH v14 01/10] dt-bindings: mediatek,dp: Add Display Port binding
From: Rob Herring <robh@kernel.org>
Date: 2022-07-18 20:21:19
Also in:
dri-devel, linux-arm-kernel, linux-devicetree, linux-mediatek, lkml
On Tue, Jul 12, 2022 at 07:12:14PM +0800, Bo-Chen Chen wrote:
quoted hunk ↗ jump to hunk
From: Markus Schneider-Pargmann <msp@baylibre.com> This controller is present on several mediatek hardware. Currently mt8195 and mt8395 have this controller without a functional difference, so only one compatible field is added. The controller can have two forms, as a normal display port and as an embedded display port. Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com> Signed-off-by: Guillaume Ranquet <redacted> Signed-off-by: Bo-Chen Chen <redacted> --- .../display/mediatek/mediatek,dp.yaml | 115 ++++++++++++++++++ 1 file changed, 115 insertions(+) create mode 100644 Documentation/devicetree/bindings/display/mediatek/mediatek,dp.yamldiff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,dp.yaml b/Documentation/devicetree/bindings/display/mediatek/mediatek,dp.yaml new file mode 100644 index 000000000000..e2d6cb314297 --- /dev/null +++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,dp.yaml@@ -0,0 +1,115 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/display/mediatek/mediatek,dp.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: MediaTek Display Port Controller + +maintainers: + - Chun-Kuang Hu <chunkuang.hu@kernel.org> + - Jitao shi <jitao.shi@mediatek.com> + +description: | + Device tree bindings for the MediaTek display port TX (DP) and + embedded display port TX (eDP) controller present on some MediaTek SoCs. + MediaTek DP and eDP are different hardwares and they have different + base address for registers, so we need two different compatibles to + separate them.
As I said before, 'different base address for registers' is not a reason for different compatibles. If it was, then we'd never have a compatible string appear more than once in a DT. Explain WHAT is different within the block. For example[1]. Rob [1] https://lore.kernel.org/all/20220710084133.30976-10-dmitry.baryshkov@linaro.org/ (local)
+
+properties:
+ compatible:
+ enum:
+ - mediatek,mt8195-dp-tx
+ - mediatek,mt8195-edp-tx
+
+ reg:
+ maxItems: 1
+
+ nvmem-cells:
+ maxItems: 1
+ description: efuse data for display port calibration
+
+ nvmem-cell-names:
+ const: dp_calibration_data
+
+ power-domains:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ ports:
+ $ref: /schemas/graph.yaml#/properties/ports
+ properties:
+ port@0:
+ $ref: /schemas/graph.yaml#/properties/port
+ description: Input endpoint of the controller, usually dp_intf
+
+ port@1:
+ $ref: /schemas/graph.yaml#/$defs/port-base
+ unevaluatedProperties: false
+ description: Output endpoint of the controller
+ properties:
+ endpoint:
+ $ref: /schemas/media/video-interfaces.yaml#
+ unevaluatedProperties: false
+ properties:
+ data-lanes:
+ description: |
+ number of lanes supported by the hardware.
+ The possible values:
+ 0 - For 1 lane enabled in IP.
+ 0 1 - For 2 lanes enabled in IP.
+ 0 1 2 3 - For 4 lanes enabled in IP.
+ minItems: 1
+ maxItems: 4
+ required:
+ - data-lanes
+
+ required:
+ - port@0
+ - port@1
+
+ max-linkrate-mhz:
+ enum: [ 1620, 2700, 5400, 8100 ]
+ description: maximum link rate supported by the hardware.
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - ports
+ - max-linkrate-mhz
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/power/mt8195-power.h>
+ dp_tx@1c600000 {
+ compatible = "mediatek,mt8195-dp-tx";
+ reg = <0x1c600000 0x8000>;
+ power-domains = <&spm MT8195_POWER_DOMAIN_DP_TX>;
+ interrupts = <GIC_SPI 458 IRQ_TYPE_LEVEL_HIGH 0>;
+ max-linkrate-mhz = <8100>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+ dptx_in: endpoint {
+ remote-endpoint = <&dp_intf0_out>;
+ };
+ };
+ port@1 {
+ reg = <1>;
+ dptx_out: endpoint {
+ data-lanes = <0 1 2 3>;
+ };
+ };
+ };
+ };
--
2.18.0