Re: [PATCH RFC 1/2] dt-bindings: display: panel: Add ChipWealth CH13726A AMOLED driver bindings

[Aaron Kling]

On Wed, Mar 4, 2026 at 2:10 PM Neil Armstrong <neil.armstrong@xxxxxxxxxx> wrote:
>
> On 3/4/26 18:56, Aaron Kling wrote:
> > On Wed, Mar 4, 2026 at 10:32 AM Neil Armstrong
> > <neil.armstrong@xxxxxxxxxx> wrote:
> >>
> >> On 2/22/26 23:26, Aaron Kling via B4 Relay wrote:
> >>> From: Aaron Kling <webgeek1234@xxxxxxxxx>
> >>>
> >>> The Chip Wealth Technology CH13726A display driver is a single chip
> >>> solution for AMOLED using MIPI-DSI. This is used for the AYN Thor bottom
> >>> panel.
> >>>
> >>> Signed-off-by: Aaron Kling <webgeek1234@xxxxxxxxx>
> >>> ---
> >>>    .../display/panel/chipwealth,ch13726a.yaml         | 66 ++++++++++++++++++++++
> >>>    1 file changed, 66 insertions(+)
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/display/panel/chipwealth,ch13726a.yaml b/Documentation/devicetree/bindings/display/panel/chipwealth,ch13726a.yaml
> >>> new file mode 100644
> >>> index 0000000000000000000000000000000000000000..890984b00c341285066176995e6a973c5607cbde
> >>> --- /dev/null
> >>> +++ b/Documentation/devicetree/bindings/display/panel/chipwealth,ch13726a.yaml
> >>> @@ -0,0 +1,66 @@
> >>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> >>> +%YAML 1.2
> >>> +---
> >>> +$id: http://devicetree.org/schemas/display/panel/chipwealth,ch13726a.yaml#
> >>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> >>> +
> >>> +title: Chip Wealth Technology CH13726A display driver
> >>> +
> >>> +maintainers:
> >>> +  - Place Holder <place@xxxxxxxxxx>
> >>
> >> ??
> >
> > Please see my reply on the cover [0].
>
> Sorry my bad, yes add me it's fine
>
> >
> >>> +
> >>> +description:
> >>> +  Chip Wealth Technology CH13726A is a single-chip solution
> >>> +  for AMOLED connected using a MIPI-DSI video interface.
> >>> +
> >>> +allOf:
> >>> +  - $ref: panel-common.yaml#
> >>> +
> >>> +properties:
> >>> +  compatible:
> >>> +    const: ayntec,thor-panel-bottom
> >>
> >> ??? why not chipwealth,ch13726a ??
> >
> > Because this is a driver chip that supports multiple panels. The
> > driver code I based on also supports the retroid pocket 5 panel, which
> > has a different resolution. Similar naming is used in the rocktech
> > jh057n00900 binding, which is why I picked this compatible.
>
> It doesn't work like that, add a compatible per physical device, not
> by driver. You can add common fallbacks if the panel is the same as another.

So what should it look like then? The ch13726a is a chip that supports
multiple panels. The one I'm adding here is a 1240x1080 panel, no idea
what the manufacturer or model number is, just that it's used as the
bottom panel in the AYN Thor. The chip also supports a 1080x1920 panel
as found in the Retroid Pocket 5. Among many others. If the compatible
is chipwealth,ch13726a and nothing else, then how is the driver to
know what's plugged into the chip and what to report as the supported
modes?

> >
> >>> +
> >>> +  port: true
> >>> +  reg:
> >>> +    maxItems: 1
> >>> +    description: DSI virtual channel
> >>> +
> >>> +  vdd-supply: true
> >>> +  vddio-supply: true
> >>> +  vdd1v2-supply: true
> >>> +  avdd-supply: true
> >>> +
> >>> +  reset-gpios: true
> >>> +
> >>> +  rotation: true
> >>> +
> >>> +required:
> >>> +  - compatible
> >>> +  - reg
> >>> +  - vdd-supply
> >>> +  - vddio-supply
> >>> +  - vdd1v2-supply
> >>> +  - avdd-supply
> >>> +  - reset-gpios
> >>> +
> >>> +additionalProperties: false
> >>> +
> >>> +examples:
> >>> +  - |
> >>> +    #include <dt-bindings/gpio/gpio.h>
> >>> +
> >>> +    dsi {
> >>> +        #address-cells = <1>;
> >>> +        #size-cells = <0>;
> >>> +        panel@0 {
> >>> +            compatible = "ayntec,thor-panel-bottom";
> >>> +            reg = <0>;
> >>> +            vdd1v2-supply = <&vreg_l11b_1p2>;
> >>> +            vddio-supply = <&vdd_disp_1v8>;
> >>> +            vdd-supply = <&vreg_l13b_3p0>;
> >>> +            avdd-supply = <&vdd_disp2_2v8>;
> >>> +            reset-gpios = <&tlmm 133 GPIO_ACTIVE_HIGH>;
> >>> +        };
> >>> +    };
> >>> +
> >>> +...
> >>>
> >>
> >
> > Aaron
> >
> > [0] https://lore.kernel.org/dri-devel/20260222-ch13726a-v1-0-e501d78e105a@xxxxxxxxx/
>