[PATCH v4] dt-bindings: display: ti, am65x-dss: Fix AM62L DSS reg and clock constraints

From: Swamil Jain

Date: Wed Apr 15 2026 - 07:04:35 EST


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@xxxxxxxxxxxxxxx
Signed-off-by: Swamil Jain <s-jain1@xxxxxx>
---
Validated the changes with some examples:
https://gist.github.com/swamiljain/79f30568c9ece89f5a20218f52647486

Changelog:
v3->v4:
- Add reg-names constraint
- Re-order constraints to make it consistent with the properties order

Link to v3:
https://lore.kernel.org/all/20260410105955.843868-1-s-jain1@xxxxxx/

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@xxxxxx/

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@xxxxxx/
---
.../bindings/display/ti/ti,am65x-dss.yaml | 70 ++++++++++++++-----
1 file changed, 52 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..49a007cbcd3a 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 +195,24 @@ allOf:
ports:
properties:
port@1: false
+ reg:
+ maxItems: 5
+ reg-names:
+ maxItems: 5
+ clocks:
+ maxItems: 2
+ clock-names:
+ maxItems: 2
+ else:
+ properties:
+ reg:
+ minItems: 8
+ reg-names:
+ minItems: 8
+ clocks:
+ minItems: 3
+ clock-names:
+ minItems: 3

- if:
properties: