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[PATCH v3 1/4] dt-bindings: display: Add Himax HX8394 panel controller

Javier Martinez Canillas posted 4 patches 2 years, 8 months ago
There is a newer version of this series
[PATCH v3 1/4] dt-bindings: display: Add Himax HX8394 panel controller
Posted by Javier Martinez Canillas 2 years, 8 months ago 
Add device tree bindings for panels based on the Himax HX8394 controller,
such as the HannStar HSD060BHW4 720x1440 TFT LCD panel that is connected
through a MIPI-DSI video interface.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---

Changes in v3:
- Fix example snippet for `make dt_binding_check` to pass (Krzysztof Kozlowski).

Changes in v2:
- Drop redundant "bindings" in subject (Krzysztof Kozlowski).
- Drop "device tree bindings" in title (Krzysztof Kozlowski).
- Put port next to other "true" properties (Krzysztof Kozlowski).
- Add Krzysztof Kozlowski's Reviewed-by tag.

 .../bindings/display/panel/himax,hx8394.yaml  | 74 +++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/panel/himax,hx8394.yaml

diff --git a/Documentation/devicetree/bindings/display/panel/himax,hx8394.yaml b/Documentation/devicetree/bindings/display/panel/himax,hx8394.yaml
new file mode 100644
index 000000000000..fb1981cacfc8
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/himax,hx8394.yaml
@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/panel/himax,hx8394.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Himax HX8394 MIPI-DSI LCD panel controller
+
+maintainers:
+  - Javier Martinez Canillas <javierm@redhat.com>
+
+description:
+  Device tree bindings for panels based on the Himax HX8394 controller,
+  such as the HannStar HSD060BHW4 720x1440 TFT LCD panel connected with
+  a MIPI-DSI video interface.
+
+allOf:
+  - $ref: panel-common.yaml#
+
+properties:
+  compatible:
+    enum:
+      # HannStar HSD060BHW4 5.99" 720x1440 TFT LCD panel
+      - hannstar,hsd060bhw4
+
+  reg: true
+
+  reset-gpios: true
+
+  backlight: true
+
+  port: true
+
+  vcc-supply:
+    description: Panel power supply
+
+  iovcc-supply:
+    description: I/O voltage supply
+
+required:
+  - compatible
+  - reg
+  - reset-gpios
+  - backlight
+  - port
+  - vcc-supply
+  - iovcc-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    dsi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        panel@0 {
+            compatible = "hannstar,hsd060bhw4";
+            reg = <0>;
+            vcc-supply = <&reg_2v8_p>;
+            iovcc-supply = <&reg_1v8_p>;
+            reset-gpios = <&gpio3 13 GPIO_ACTIVE_LOW>;
+            backlight = <&backlight>;
+
+            port {
+                mipi_in_panel: endpoint {
+                    remote-endpoint = <&mipi_out_panel>;
+                };
+            };
+        };
+    };
+
+...
-- 
2.38.1
Re: [PATCH v3 1/4] dt-bindings: display: Add Himax HX8394 panel controller
Posted by Jagan Teki 2 years, 8 months ago 
On Tue, Dec 27, 2022 at 4:33 PM Javier Martinez Canillas
<javierm@redhat.com> wrote:
>
> Add device tree bindings for panels based on the Himax HX8394 controller,
> such as the HannStar HSD060BHW4 720x1440 TFT LCD panel that is connected
> through a MIPI-DSI video interface.
>
> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> ---
>
> Changes in v3:
> - Fix example snippet for `make dt_binding_check` to pass (Krzysztof Kozlowski).
>
> Changes in v2:
> - Drop redundant "bindings" in subject (Krzysztof Kozlowski).
> - Drop "device tree bindings" in title (Krzysztof Kozlowski).
> - Put port next to other "true" properties (Krzysztof Kozlowski).
> - Add Krzysztof Kozlowski's Reviewed-by tag.
>
>  .../bindings/display/panel/himax,hx8394.yaml  | 74 +++++++++++++++++++
>  1 file changed, 74 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/panel/himax,hx8394.yaml
>
> diff --git a/Documentation/devicetree/bindings/display/panel/himax,hx8394.yaml b/Documentation/devicetree/bindings/display/panel/himax,hx8394.yaml
> new file mode 100644
> index 000000000000..fb1981cacfc8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/panel/himax,hx8394.yaml
> @@ -0,0 +1,74 @@
> +# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/panel/himax,hx8394.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Himax HX8394 MIPI-DSI LCD panel controller
> +
> +maintainers:
> +  - Javier Martinez Canillas <javierm@redhat.com>
> +
> +description:
> +  Device tree bindings for panels based on the Himax HX8394 controller,
> +  such as the HannStar HSD060BHW4 720x1440 TFT LCD panel connected with
> +  a MIPI-DSI video interface.
> +
> +allOf:
> +  - $ref: panel-common.yaml#
> +
> +properties:
> +  compatible:
> +    enum:
> +      # HannStar HSD060BHW4 5.99" 720x1440 TFT LCD panel
> +      - hannstar,hsd060bhw4

Parent controller can have a compatible where the associated panels
will be enum list.

Jagan.
Re: [PATCH v3 1/4] dt-bindings: display: Add Himax HX8394 panel controller
Posted by Javier Martinez Canillas 2 years, 8 months ago 
Hello Jagan,

On Tue, Dec 27, 2022 at 7:16 PM Jagan Teki <jagan@amarulasolutions.com> wrote:

[...]

> > +allOf:
> > +  - $ref: panel-common.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      # HannStar HSD060BHW4 5.99" 720x1440 TFT LCD panel
> > +      - hannstar,hsd060bhw4
>
> Parent controller can have a compatible where the associated panels
> will be enum list.
>

I'm not sure to follow what you meant. Could you please elaborate?

Best regards,
Javier
Re: [PATCH v3 1/4] dt-bindings: display: Add Himax HX8394 panel controller
Posted by Jagan Teki 2 years, 8 months ago 
On Wed, Dec 28, 2022 at 12:58 AM Javier Martinez Canillas
<javier@dowhile0.org> wrote:
>
> Hello Jagan,
>
> On Tue, Dec 27, 2022 at 7:16 PM Jagan Teki <jagan@amarulasolutions.com> wrote:
>
> [...]
>
> > > +allOf:
> > > +  - $ref: panel-common.yaml#
> > > +
> > > +properties:
> > > +  compatible:
> > > +    enum:
> > > +      # HannStar HSD060BHW4 5.99" 720x1440 TFT LCD panel
> > > +      - hannstar,hsd060bhw4
> >
> > Parent controller can have a compatible where the associated panels
> > will be enum list.
> >
>
> I'm not sure to follow what you meant. Could you please elaborate?

compatible:
    items:
      - enum:
          - hannstar,hsd060bhw4
      - const: himax,hx8394

himax,hx8394 is the actual controller and is denoted as fallback compatible.

Jagan.
Re: [PATCH v3 1/4] dt-bindings: display: Add Himax HX8394 panel controller
Posted by Javier Martinez Canillas 2 years, 8 months ago 
On Tue, Dec 27, 2022 at 8:37 PM Jagan Teki <jagan@amarulasolutions.com> wrote:
>
> On Wed, Dec 28, 2022 at 12:58 AM Javier Martinez Canillas
> <javier@dowhile0.org> wrote:
> >
> > Hello Jagan,
> >
> > On Tue, Dec 27, 2022 at 7:16 PM Jagan Teki <jagan@amarulasolutions.com> wrote:
> >
> > [...]
> >
> > > > +allOf:
> > > > +  - $ref: panel-common.yaml#
> > > > +
> > > > +properties:
> > > > +  compatible:
> > > > +    enum:
> > > > +      # HannStar HSD060BHW4 5.99" 720x1440 TFT LCD panel
> > > > +      - hannstar,hsd060bhw4
> > >
> > > Parent controller can have a compatible where the associated panels
> > > will be enum list.
> > >
> >
> > I'm not sure to follow what you meant. Could you please elaborate?
>
> compatible:
>     items:
>       - enum:
>           - hannstar,hsd060bhw4
>       - const: himax,hx8394
>
> himax,hx8394 is the actual controller and is denoted as fallback compatible.
>

I see. Do you have an example of a panel controller that does this? I
don't see that much value in doing this since you want the DTS to
describe the actual HW and so want the panel I believe.

But also there isn't an of_device_id entry for this fallback
controller compatible string. Feel free to propose that as a follow-up
if you think it is worth doing so.

Best regards,
Javier
Re: [PATCH v3 1/4] dt-bindings: display: Add Himax HX8394 panel controller
Posted by Jagan Teki 2 years, 8 months ago 
On Wed, Dec 28, 2022 at 3:46 AM Javier Martinez Canillas
<javier@dowhile0.org> wrote:
>
> On Tue, Dec 27, 2022 at 8:37 PM Jagan Teki <jagan@amarulasolutions.com> wrote:
> >
> > On Wed, Dec 28, 2022 at 12:58 AM Javier Martinez Canillas
> > <javier@dowhile0.org> wrote:
> > >
> > > Hello Jagan,
> > >
> > > On Tue, Dec 27, 2022 at 7:16 PM Jagan Teki <jagan@amarulasolutions.com> wrote:
> > >
> > > [...]
> > >
> > > > > +allOf:
> > > > > +  - $ref: panel-common.yaml#
> > > > > +
> > > > > +properties:
> > > > > +  compatible:
> > > > > +    enum:
> > > > > +      # HannStar HSD060BHW4 5.99" 720x1440 TFT LCD panel
> > > > > +      - hannstar,hsd060bhw4
> > > >
> > > > Parent controller can have a compatible where the associated panels
> > > > will be enum list.
> > > >
> > >
> > > I'm not sure to follow what you meant. Could you please elaborate?
> >
> > compatible:
> >     items:
> >       - enum:
> >           - hannstar,hsd060bhw4
> >       - const: himax,hx8394
> >
> > himax,hx8394 is the actual controller and is denoted as fallback compatible.
> >
>
> I see. Do you have an example of a panel controller that does this? I
> don't see that much value in doing this since you want the DTS to
> describe the actual HW and so want the panel I believe.

Yes, but the Panel needs to be built on top of the display IC so the
actual parent here is the display IC and the panel is sub-HW.  This is
what usually follows, here are some reference bindings.

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/display/panel/jadard,jd9365da-h3.yaml
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/display/panel/sitronix,st7701.yaml
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/display/panel/ilitek,ili9163.yaml
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/display/panel/ilitek,ili9322.yaml

Jagan.

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