[PATCH 3/3] dt-bindings: i2c: realtek,rtl9301-i2c: extend for RTL9310 support

[Jonas Jelonek <jelonek.jonas@gmail.com>]

This extends the dt-bindings for the I2C driver for RTL9300 to account
for the added support for RTL9310 series.

A new property is added to explicitly set the SCL num/hardware instance
of the controller that is used. In contrast to RTL9300 the driver needs
to know that explicitly for RTL9310 because the SCL selection is now in
a global register instead of a master-specific register.

The regex for child-node address is adjusted to account for the fact
that RTL9310 supports 12 instead of 8 SDA lines.

A single generic compatible "realtek,rtl9310-i2c" is added. To best
knowledge, all existing SoCs of RTL9310 series (RTL9311, RTL9312,
RTL9313) have equal I2C capabilities thus don't need special treatment.
However, in the unlikely case of future differences with specific
SoCs within this series, more can be added as needed.

Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>
---
 .../bindings/i2c/realtek,rtl9301-i2c.yaml     | 33 ++++++++++++++++---
 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/realtek,rtl9301-i2c.yaml b/Documentation/devicetree/bindings/i2c/realtek,rtl9301-i2c.yaml
index eddfd329c67b..3b32da3de2af 100644
--- a/Documentation/devicetree/bindings/i2c/realtek,rtl9301-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/realtek,rtl9301-i2c.yaml
@@ -10,9 +10,11 @@ maintainers:
   - Chris Packham <chris.packham@alliedtelesis.co.nz>
 
 description:
-  The RTL9300 SoC has two I2C controllers. Each of these has an SCL line (which
-  if not-used for SCL can be a GPIO). There are 8 common SDA lines that can be
-  assigned to either I2C controller.
+  The RTL9300 SoCs have two I2C controllers. Each of these has an SCL line
+  (which if not-used for SCL can be a GPIO). There are 8 common SDA lines
+  that can be assigned to either I2C controller.
+  The RTL9310 SoCs have equal capabilities but support 12 common SDA lines
+  which can be assigned to either I2C controller.
 
 properties:
   compatible:
@@ -24,6 +26,7 @@ properties:
               - realtek,rtl9303-i2c
           - const: realtek,rtl9301-i2c
       - const: realtek,rtl9301-i2c
+      - const: realtek,rtl9310-i2c
 
   reg:
     description: Register offset and size this I2C controller.
@@ -34,8 +37,18 @@ properties:
   "#size-cells":
     const: 0
 
+  scl-num:
+    $ref: /schemas/types.yaml#/definitions/uint8
+    description:
+      SCL number (0 or 1) to select I2C hardware instance. SCL0
+      is hardwired to master 1 and SCL1 to master 2.
+      Required only on RTL9310 if both or only second master
+      is used.
+    minimum: 0
+    maximum: 1
+
 patternProperties:
-  '^i2c@[0-7]$':
+  '^i2c@([0-9]|1[0-1])$':
     $ref: /schemas/i2c/i2c-controller.yaml
     unevaluatedProperties: false
 
@@ -67,3 +80,15 @@ examples:
         #size-cells = <0>;
       };
     };
+  - |
+    i2c@100c {
+      compatible = "realtek,rtl9310-i2c";
+      reg = <0x100c 0x18>;
+      #address-cells = <1>;
+      #size-cells = <0>;
+      scl-num = <0>;
+
+      i2c@0 {
+        reg = <0>;
+      };
+    };
-- 
2.48.1