Re: [PATCH v4 4/5] dt-bindings: display: Add Synaptics R63455 panel support

[Neil Armstrong <neil.armstrong@linaro.org>]

On 5/21/26 22:24, Dmitry Baryshkov wrote:
> On Thu, May 21, 2026 at 10:46:06PM +0800, Jun Nie wrote:
>> Add support for the dual-panel system found in the virtual reality device.
>> This system consists of two physical 2160x2160 panels, each connected via
>> a MIPI DSI interface. The backlight is managed through DSI link.
>>
>> Signed-off-by: Jun Nie <jun.nie@linaro.org>
>> ---
>>   .../bindings/display/panel/synaptics,r63455.yaml   | 125 +++++++++++++++++++++
>>   1 file changed, 125 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/display/panel/synaptics,r63455.yaml b/Documentation/devicetree/bindings/display/panel/synaptics,r63455.yaml
>> new file mode 100644
>> index 0000000000000..a94b355ed9557
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/display/panel/synaptics,r63455.yaml
>> @@ -0,0 +1,125 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/display/panel/synaptics,r63455.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Synaptics R63455 based dual 2160x2160 MIPI-DSI Panel
>> +
>> +maintainers:
>> +  - Jun Nie <jun.nie@linaro.org>
>> +
>> +description:
>> +  Synaptics R63455 is a Virtual Reality Display Driver and VR Bridge, used in
>> +  pair in Headset devices. The Virtual Reality Display complex is composed of
>> +  two strictly identical display panels, each driven by its own DSI interface
>> +  but forms a single virtual display for the human eye perception and thus
>> +  requires a strict synchronization of the two display panel content update.
>> +
>> +allOf:
>> +  - $ref: panel-common.yaml#
>> +
>> +properties:
>> +  compatible:
>> +    items:
>> +      - enum:
>> +        - sharp,ls026b3sa06
>> +        - boe,vs026c4m-n52-6000
>> +      - const: synaptics,r63455
>> +
>> +  reset-gpios:
>> +    maxItems: 2
>> +    description: 2 reset pins for 2 physical panels
>> +
>> +  left-pos-supply:
>> +    description: Positive 5.7V supply for left panel
> 
> So, is the R63455 driving both panels or are there two panels, each
> having R63455 controller? What if somebody gets a single Sharp panel and
> wants to use it in their device? How will it match these bindings?

It's highly improbable, those are very specialized panels that are designed
for xr usage in pair. Yes a hobbyist could try to use a single panel
but it's only usable when placed close to an eye, and barely useless if you
don't have both eyes.

Let's skip highly improbable use-cases and focus on the main use case of the
hardware device.

> 
>> +
>> +  right-pos-supply:
>> +    description: Positive 5.7V supply for right panel
>> +
>> +  left-neg-supply:
>> +    description: Negative 5.7V supply for left panel
>> +
>> +  right-neg-supply:
>> +    description: Negative 5.7V supply for right panel
>> +
>> +  left-backlight-supply:
>> +    description: Backlight 21V supply for left panel
>> +
>> +  right-backlight-supply:
>> +    description: Backlight 21V supply for right panel
>> +
>> +  vdda-supply:
>> +    description: core 1.8V supply for panels
>> +
>> +  ports: $ref: /schemas/graph.yaml#/properties/ports
>> +
>> +required:
>> +  - compatible
>> +  - reset-gpios
>> +  - left-pos-supply
>> +  - left-neg-supply
>> +  - right-pos-supply
>> +  - right-neg-supply
>> +  - left-backlight-supply
>> +  - right-backlight-supply
>> +  - vdda-supply
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/gpio/gpio.h>
>> +
>> +    &mdss_dsi0 {
> 
> Please drop the MDSS specifics, there should be one (or two) DSI busses,
> driving your panels. The rests are details which are not necessary for
> the example.
> 
>> +        vdda-supply = <&vreg_l3i_1p2>;
>> +        status = "okay";
>> +
>> +        qcom,dual-dsi-mode;
>> +        qcom,master-dsi;
>> +
>> +        panel: panel@0 {
>> +            compatible = "sharp,ls026b3sa06", "synaptics,r63455";
>> +            reg = <0>;
>> +
>> +            reset-gpios = <&pm8550_gpios 3 GPIO_ACTIVE_HIGH>,
>> +                          <&pm8550_gpios 11 GPIO_ACTIVE_HIGH>;
>> +
>> +            left-pos-supply = <&vpos_left>;
>> +            left-neg-supply = <&vneg_left>;
>> +            right-pos-supply = <&vpos_right>;
>> +            right-neg-supply = <&vneg_right>;
>> +            left-backlight-supply = <&backlight_left>;
>> +            right-backlight-supply = <&backlight_right>;
>> +
>> +            vdda-supply = <&vreg_l12b_1p8>;
>> +
>> +            ports {
>> +                #address-cells = <1>;
>> +                #size-cells = <0>;
>> +                port@0 {
>> +                    reg = <0>;
>> +                    panel0_in: endpoint {
>> +                        remote-endpoint = <&mdss_dsi0_out>;
> 
> What is mdss_dsi0_out?
> 
>> +                    };
>> +                };
>> +
>> +                port@1 {
>> +                    reg = <1>;
>> +                    panel1_in: endpoint {
>> +                        remote-endpoint = <&mdss_dsi1_out>;
>> +                    };
>> +                };
>> +            };
>> +    };
>> +
>> +    &mdss_dsi0_out {
>> +            remote-endpoint = <&panel0_in>;
>> +            data-lanes = <0 1 2>;
>> +    };
>> +
>> +    &mdss_dsi1_out {
>> +            remote-endpoint = <&panel1_in>;
>> +            data-lanes = <0 1 2>;
>> +    };
>> +...
>>
>> -- 
>> 2.43.0
>>
>