[PATCH v5 1/6] dt-bindings: media: sun6i-a31-csi: Add MIPI CSI-2 input port

[Paul Kocialkowski]

The A31 CSI controller supports two distinct input interfaces:
parallel and an external MIPI CSI-2 bridge. The parallel interface
is often connected to a set of hardware pins while the MIPI CSI-2
bridge is an internal FIFO-ish link. As a result, these two inputs
are distinguished as two different ports.

Note that only one of the two may be present on a controller instance.
For example, the V3s has one controller dedicated to MIPI-CSI2 and one
dedicated to parallel.

Update the binding with an explicit ports node that holds two distinct
port nodes: one for parallel input and one for MIPI CSI-2.

This is backward-compatible with the single-port approach that was
previously taken for representing the parallel interface port, which
stays enumerated as fwnode port 0.

Note that additional ports may be added in the future, especially to
support feeding the CSI controller's output to the ISP.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski at bootlin.com>
Reviewed-by: Rob Herring <robh at kernel.org>
Acked-by: Maxime Ripard <mripard at kernel.org>
---
 .../media/allwinner,sun6i-a31-csi.yaml        | 58 ++++++++++++++-----
 1 file changed, 44 insertions(+), 14 deletions(-)

diff --git a/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-csi.yaml b/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-csi.yaml
index 8b568072a069..8551c4a711dc 100644
--- a/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-csi.yaml
+++ b/Documentation/devicetree/bindings/media/allwinner,sun6i-a31-csi.yaml
@@ -42,6 +42,7 @@ properties:
 
   port:
     $ref: /schemas/graph.yaml#/$defs/port-base
+    description: Parallel input port, connect to a parallel sensor
 
     properties:
       endpoint:
@@ -59,7 +60,24 @@ properties:
         required:
           - bus-width
 
-    additionalProperties: false
+    unevaluatedProperties: false
+
+  ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+
+    properties:
+      port at 0:
+        $ref: "#/properties/port"
+
+      port at 1:
+        $ref: /schemas/graph.yaml#/properties/port
+        description: MIPI CSI-2 bridge input port
+
+    anyOf:
+      - required:
+          - port at 0
+      - required:
+          - port at 1
 
 required:
   - compatible
@@ -69,6 +87,12 @@ required:
   - clock-names
   - resets
 
+oneOf:
+  - required:
+      - ports
+  - required:
+      - port
+
 additionalProperties: false
 
 examples:
@@ -89,19 +113,25 @@ examples:
                       "ram";
         resets = <&ccu RST_BUS_CSI>;
 
-        port {
-            /* Parallel bus endpoint */
-            csi1_ep: endpoint {
-                remote-endpoint = <&adv7611_ep>;
-                bus-width = <16>;
-
-                /*
-                 * If hsync-active/vsync-active are missing,
-                 * embedded BT.656 sync is used.
-                 */
-                 hsync-active = <0>; /* Active low */
-                 vsync-active = <0>; /* Active low */
-                 pclk-sample = <1>;  /* Rising */
+        ports {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            port at 0 {
+                reg = <0>;
+                /* Parallel bus endpoint */
+                csi1_ep: endpoint {
+                    remote-endpoint = <&adv7611_ep>;
+                    bus-width = <16>;
+
+                    /*
+                     * If hsync-active/vsync-active are missing,
+                     * embedded BT.656 sync is used.
+                     */
+                    hsync-active = <0>; /* Active low */
+                    vsync-active = <0>; /* Active low */
+                    pclk-sample = <1>;  /* Rising */
+                };
             };
         };
     };
-- 
2.36.1