From ca26126a6c3fb6eb4f30ceb6a41ff975117ec94a Mon Sep 17 00:00:00 2001
From: Jai Luthra <jai.luthra@ideasonboard.com>
Date: Mon, 3 Mar 2025 21:32:19 +0530
Subject: [PATCH] media: dt-bindings: ti,ds90ub960: Allow setting serializer
 address

The serializer's I2C address on the FPD-Link bus is usually communicated
to the deserializer once the forward-channel is established. But in some
cases it might be necessary to program the serializer (over the
back-channel) before the forward-channel is established.

This can be used e.g. to correct serializer configuration which
otherwise would prevent the FC to be enabled. To be able to communicate
to the serializer before the forward-channel is up, the deserializer
driver neds to know the default i2c address of the serializer.

Allow setting the serializer i2c address using the 'reg' property. This
is optional, and usually not needed.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
---
 .../bindings/media/i2c/ti,ds90ub953.yaml      | 77 +++++++++++--------
 .../bindings/media/i2c/ti,ds90ub960.yaml      | 16 +++-
 2 files changed, 58 insertions(+), 35 deletions(-)

diff --git a/Documentation/devicetree/bindings/media/i2c/ti,ds90ub953.yaml b/Documentation/devicetree/bindings/media/i2c/ti,ds90ub953.yaml
index 2030366994d18..2e129bf573b79 100644
--- a/Documentation/devicetree/bindings/media/i2c/ti,ds90ub953.yaml
+++ b/Documentation/devicetree/bindings/media/i2c/ti,ds90ub953.yaml
@@ -38,6 +38,13 @@ properties:
   '#clock-cells':
     const: 0
 
+  reg:
+    maxItems: 1
+    description:
+      The strap I2C address of the serializer. Can be used by the deserializer
+      to communicate over back-channel when the forward-channel is not yet
+      active.
+
   ports:
     $ref: /schemas/graph.yaml#/properties/ports
 
@@ -81,51 +88,57 @@ examples:
   - |
     #include <dt-bindings/gpio/gpio.h>
 
-    serializer {
-      compatible = "ti,ds90ub953-q1";
+    link {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      serializer@18 {
+        compatible = "ti,ds90ub953-q1";
+        reg = <0x18>;
 
-      gpio-controller;
-      #gpio-cells = <2>;
+        gpio-controller;
+        #gpio-cells = <2>;
 
-      #clock-cells = <0>;
+        #clock-cells = <0>;
 
-      ports {
-        #address-cells = <1>;
-        #size-cells = <0>;
+        ports {
+          #address-cells = <1>;
+          #size-cells = <0>;
 
-        port@0 {
-          reg = <0>;
-          ub953_in: endpoint {
-            clock-lanes = <0>;
-            data-lanes = <1 2 3 4>;
-            remote-endpoint = <&sensor_out>;
+          port@0 {
+            reg = <0>;
+            ub953_in: endpoint {
+              clock-lanes = <0>;
+              data-lanes = <1 2 3 4>;
+              remote-endpoint = <&sensor_out>;
+            };
           };
-        };
 
-        port@1 {
-          reg = <1>;
-          endpoint {
-            remote-endpoint = <&deser_fpd_in>;
+          port@1 {
+            reg = <1>;
+            endpoint {
+              remote-endpoint = <&deser_fpd_in>;
+            };
           };
         };
-      };
 
-      i2c {
-        #address-cells = <1>;
-        #size-cells = <0>;
+        i2c {
+          #address-cells = <1>;
+          #size-cells = <0>;
 
-        sensor@1a {
-          compatible = "sony,imx274";
-          reg = <0x1a>;
+          sensor@1a {
+            compatible = "sony,imx274";
+            reg = <0x1a>;
 
-          reset-gpios = <&serializer 0 GPIO_ACTIVE_LOW>;
+            reset-gpios = <&serializer 0 GPIO_ACTIVE_LOW>;
 
-          clocks = <&serializer>;
-          clock-names = "inck";
+            clocks = <&serializer>;
+            clock-names = "inck";
 
-          port {
-            sensor_out: endpoint {
-              remote-endpoint = <&ub953_in>;
+            port {
+              sensor_out: endpoint {
+                remote-endpoint = <&ub953_in>;
+              };
             };
           };
         };
diff --git a/Documentation/devicetree/bindings/media/i2c/ti,ds90ub960.yaml b/Documentation/devicetree/bindings/media/i2c/ti,ds90ub960.yaml
index 0b71e6f911a88..4dcbd2b039a58 100644
--- a/Documentation/devicetree/bindings/media/i2c/ti,ds90ub960.yaml
+++ b/Documentation/devicetree/bindings/media/i2c/ti,ds90ub960.yaml
@@ -68,6 +68,12 @@ properties:
             description: The link number
             maxItems: 1
 
+          '#address-cells':
+            const: 1
+
+          '#size-cells':
+            const: 0
+
           i2c-alias:
             $ref: /schemas/types.yaml#/definitions/uint32
             description:
@@ -107,7 +113,8 @@ properties:
             maximum: 14
             description: Manual EQ level
 
-          serializer:
+        patternProperties:
+          '^serializer(@[0-9a-f]+)*$':
             type: object
             description: FPD-Link Serializer node
 
@@ -115,7 +122,6 @@ properties:
           - reg
           - i2c-alias
           - ti,rx-mode
-          - serializer
 
   ports:
     $ref: /schemas/graph.yaml#/properties/ports
@@ -309,13 +315,17 @@ examples:
           /* Link 0 has DS90UB953 serializer and IMX274 sensor */
 
           link@0 {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
             reg = <0>;
             i2c-alias = <0x44>;
 
             ti,rx-mode = <3>;
 
-            serializer1: serializer {
+            serializer1: serializer@30 {
               compatible = "ti,ds90ub953-q1";
+              reg = <0x30>;
 
               gpio-controller;
               #gpio-cells = <2>;
-- 
2.47.2