[PATCH v3] dt-bindings: display: ti, am65x-dss: Fix AM62L DSS reg and clock constraints

[PATCH v3] dt-bindings: display: ti, am65x-dss: Fix AM62L DSS reg and clock constraints

[Swamil Jain]

The AM62L DSS [1] support incorrectly used the same register and
clock constraints as AM65x, but AM62L has a single video port

Fix this by adding conditional constraints that properly define the
register regions and clocks for AM62L DSS (single video port) versus
other AM65x variants (dual video port).

[1]: Section 12.7 (Display Subsystem and Peripherals)
Link : https://www.ti.com/lit/pdf/sprujb4

Fixes: cb8d4323302c ("dt-bindings: display: ti,am65x-dss: Add support for AM62L DSS")
Cc: stable@vger.kernel.org
Signed-off-by: Swamil Jain <s-jain1@ti.com>
---
Validated the changes with some examples:
https://gist.github.com/swamiljain/79f30568c9ece89f5a20218f52647486

Changelog:
v2->v3:
- Reduce redundancy and use constraints suggested by maintainers
- Remove blank line between the tags

Link to v2:
https://lore.kernel.org/all/20260129150601.185882-1-s-jain1@ti.com/

v1->v2:
- Remove oneOf from top level constraints, it makes bindings redundant
- Remove minItems from top level constraints
- "dma-coherent" property shouldn't be changed in v1 itself
- Add description for reg-names, clock and clock-names
- Add constraints specific to AM62L and for other SoCs within allOf
  check

Link to v1:
https://lore.kernel.org/all/20251224133150.2266524-1-s-jain1@ti.com/
---
 .../bindings/display/ti/ti,am65x-dss.yaml     | 66 ++++++++++++++-----
 1 file changed, 48 insertions(+), 18 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml b/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml
index 38fcee91211e..d8a05bf62c2f 100644
--- a/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml
+++ b/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml
@@ -36,34 +36,50 @@ properties:
   reg:
     description:
       Addresses to each DSS memory region described in the SoC's TRM.
-    items:
-      - description: common DSS register area
-      - description: VIDL1 light video plane
-      - description: VID video plane
-      - description: OVR1 overlay manager for vp1
-      - description: OVR2 overlay manager for vp2
-      - description: VP1 video port 1
-      - description: VP2 video port 2
-      - description: common1 DSS register area
+    oneOf:
+      - items:
+          - description: common DSS register area
+          - description: VIDL1 light video plane
+          - description: VID video plane
+          - description: OVR1 overlay manager for vp1
+          - description: OVR2 overlay manager for vp2
+          - description: VP1 video port 1
+          - description: VP2 video port 2
+          - description: common1 DSS register area
+      - items:
+          - description: common DSS register area
+          - description: VIDL1 light video plane
+          - description: OVR1 overlay manager for vp1
+          - description: VP1 video port 1
+          - description: common1 DSS register area
 
   reg-names:
-    items:
-      - const: common
-      - const: vidl1
-      - const: vid
-      - const: ovr1
-      - const: ovr2
-      - const: vp1
-      - const: vp2
-      - const: common1
+    oneOf:
+      - items:
+          - const: common
+          - const: vidl1
+          - const: vid
+          - const: ovr1
+          - const: ovr2
+          - const: vp1
+          - const: vp2
+          - const: common1
+      - items:
+          - const: common
+          - const: vidl1
+          - const: ovr1
+          - const: vp1
+          - const: common1
 
   clocks:
+    minItems: 2
     items:
       - description: fck DSS functional clock
       - description: vp1 Video Port 1 pixel clock
       - description: vp2 Video Port 2 pixel clock
 
   clock-names:
+    minItems: 2
     items:
       - const: fck
       - const: vp1
@@ -179,6 +195,20 @@ allOf:
         ports:
           properties:
             port@1: false
+        clock-names:
+          maxItems: 2
+        clocks:
+          maxItems: 2
+        reg:
+          maxItems: 5
+    else:
+      properties:
+        clock-names:
+          minItems: 3
+        clocks:
+          minItems: 3
+        reg:
+          minItems: 8
 
   - if:
       properties:

Re: [PATCH v3] dt-bindings: display: ti, am65x-dss: Fix AM62L DSS reg and clock constraints

[Krzysztof Kozlowski]

On Fri, Apr 10, 2026 at 04:29:55PM +0530, Swamil Jain wrote:
>    clocks:
> +    minItems: 2
>      items:
>        - description: fck DSS functional clock
>        - description: vp1 Video Port 1 pixel clock
>        - description: vp2 Video Port 2 pixel clock
>  
>    clock-names:
> +    minItems: 2
>      items:
>        - const: fck
>        - const: vp1
> @@ -179,6 +195,20 @@ allOf:
>          ports:
>            properties:
>              port@1: false
> +        clock-names:
> +          maxItems: 2
> +        clocks:
> +          maxItems: 2
> +        reg:
> +          maxItems: 5

Also constrain for reg-names,

> +    else:
> +      properties:
> +        clock-names:
> +          minItems: 3
> +        clocks:
> +          minItems: 3
> +        reg:
> +          minItems: 8

Same here, please.

And if you are sending new version: they should be listed in the same
order as in top-level properties, so reg, reg-names, clocks and
clock-names. (juging by the diff)

Best regards,
Krzysztof