[PATCH v9 02/10] dt-bindings: display: Document Renesas RZ/G3E display subsystem

[Tommaso Merciai]

The Renesas RZ/G3E (R9A09G047) SoC has two LCD Controllers, LCDC0 and
LCDC1, each containing a Display Unit (DU). The two DUs are separate
instances of the same IP, with their own registers, interrupt, clocks,
reset and VSP, and are therefore described by two device tree nodes.

The DSI encoder and channel 1 of the LVDS encoder can be fed by either
DU, the source being selected at runtime. Driving those outputs from
either DU requires handling both DUs as a single display subsystem.

Document the renesas,r9a09g047-display-subsystem node that groups the
two Display Unit instances.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@xxxxxxxxxxxxxx>
---
v8->v9:
 - New patch.

 .../renesas,r9a09g047-display-subsystem.yaml  | 44 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 45 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/renesas,r9a09g047-display-subsystem.yaml

diff --git a/Documentation/devicetree/bindings/display/renesas,r9a09g047-display-subsystem.yaml b/Documentation/devicetree/bindings/display/renesas,r9a09g047-display-subsystem.yaml
new file mode 100644
index 000000000000..e23cc53a1fea
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/renesas,r9a09g047-display-subsystem.yaml
@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/renesas,r9a09g047-display-subsystem.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas RZ/G3E Display Subsystem
+
+maintainers:
+  - Tommaso Merciai <tommaso.merciai.xr@xxxxxxxxxxxxxx>
+
+description:
+  The Renesas RZ/G3E display subsystem is a virtual device needed to list the
+  Display Unit instances that comprise the graphics subsystem.
+
+properties:
+  compatible:
+    const: renesas,r9a09g047-display-subsystem
+
+  ports:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    minItems: 2
+    maxItems: 2
+    items:
+      maxItems: 1
+    description:
+      Should contain a list of phandles pointing to the ports node of the
+      Display Unit devices that comprise the display subsystem. Display Unit
+      definitions as defined in
+      Documentation/devicetree/bindings/display/renesas,rzg2l-du.yaml
+
+required:
+  - compatible
+  - ports
+
+additionalProperties: false
+
+examples:
+  - |
+    display-subsystem {
+        compatible = "renesas,r9a09g047-display-subsystem";
+        ports = <&du0_ports>, <&du1_ports>;
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 04f465490612..2f4abeb594e7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9110,6 +9110,7 @@ L:	dri-devel@xxxxxxxxxxxxxxxxxxxxx
 L:	linux-renesas-soc@xxxxxxxxxxxxxxx
 S:	Maintained
 T:	git https://gitlab.freedesktop.org/drm/misc/kernel.git
+F:	Documentation/devicetree/bindings/display/renesas,r9a09g047-display-subsystem.yaml
 F:	Documentation/devicetree/bindings/display/renesas,rzg2l-du.yaml
 F:	drivers/gpu/drm/renesas/rz-du/
 
-- 
2.54.0