Re: [PATCH v11 01/10] dt-bindings: mediatek,dp: Add Display Port binding

On Thu, 2022-06-16 at 15:28 -0600, Rob Herring wrote:

On Thu, Jun 16, 2022 at 09:22:16PM +0800, Rex-BC Chen wrote:

quoted

On Tue, 2022-06-14 at 14:23 -0600, Rob Herring wrote:

quoted

On Fri, Jun 10, 2022 at 06:55:13PM +0800, Bo-Chen Chen wrote:

quoted

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>
[Bo-Chen: Fix reviewers' comment]
Signed-off-by: Bo-Chen Chen <redacted>
---
 .../display/mediatek/mediatek,dp.yaml         | 101
++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644
Documentation/devicetree/bindings/display/mediatek/mediatek,dp.
yaml

diff --git
a/Documentation/devicetree/bindings/display/mediatek/mediatek,d
p.ya
ml
b/Documentation/devicetree/bindings/display/mediatek/mediatek,d
p.ya
ml
new file mode 100644
index 000000000000..10f50a0dcf49

--- /dev/null
+++

b/Documentation/devicetree/bindings/display/mediatek/mediatek,d
p.ya
ml

@@ -0,0 +1,101 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: 

https://urldefense.com/v3/__http://devicetree.org/schemas/display/mediatek/mediatek,dp.yaml*__;Iw!!CTRNKA9wMg0ARbw!yqAl1KhfbHqHN7-5aeqhzqeOVhPU_Z5beko5q-y-s5pcfp1WL5oVGvY5UF4EfWm4PWjc5mjBwyBUMsr_RI45ipbhsw$

quoted

quoted

quoted

 
+$schema: 

https://urldefense.com/v3/__http://devicetree.org/meta-schemas/core.yaml*__;Iw!!CTRNKA9wMg0ARbw!yqAl1KhfbHqHN7-5aeqhzqeOVhPU_Z5beko5q-y-s5pcfp1WL5oVGvY5UF4EfWm4PWjc5mjBwyBUMsr_RI5WzYKENQ$

quoted

quoted

quoted

 
+
+title: MediaTek Display Port Controller
+
+maintainers:
+  - Chun-Kuang Hu [off-list ref]
+  - Jitao shi [off-list ref]
+
+description: |
+  Device tree bindings for the MediaTek display port and
+  embedded display port controller present on some MediaTek
SoCs.
+
+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#/properties/port
+        description: Output endpoint of the controller
+
+    required:
+      - port@0
+      - port@1
+
+  max-lanes:
+    maxItems: 1
+    description: maximum number of lanes supported by the
hardware.

We already have a 'data-lanes' property defined in 
'video-interfaces.yaml' that can serve this purpose.

Hello Rob,

Thanks for review.
From the description of video-interfaces.yaml, I think it's not
quite
match what we need. We only need this value be one of "1,2,4".

data-lanes = <0>;
data-lanes = <0 1>;
data-lanes = <0 1 2 3>;

Limiting the number of lanes to something less than the max is
exactly 
how this property is used in addition to being able to show the
mapping 
of lanes.

Rob

Hello Rob,

I modify like this:
  data-lanes:
    $ref: /schemas/media/video-interfaces.yaml#
    description: |
      number of lanes supported by the hardware.
      The possible values:
      1     - For 1 lane enabled in IP.
      1 2   - For 2 lanes enabled in IP.
      1 2 4 - For 4 lanes enabled in IP.
    minItems: 1
    maxItems: 3

example:
data-lanes = <1 2 4>;

But I encounter errorr:
Documentation/devicetree/bindings/display/mediatek/mediatek,dp.example.
dtb: dp_tx@1c600000: data-lanes: [[1, 2, 4]] is not of type 'object'
Documentation/devicetree/bindings/display/mediatek/mediatek,dp.example.
dtb: dp_tx@1c600000: data-lanes: [[1, 2, 4]] is not of type 'object'

can you kindly give me some hint for this?

Thanks

BRs,
Bo-Chen


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