[PATCH v25 1/4] dt-bindings: i2c: Split AST2600 binding into a new YAML

[Ryan Chen <ryan_chen@aspeedtech.com>]

The AST2600 I2C controller introduces a completely new register layout
with separate controller and target register blocks, unlike the mixed
register layout used by AST2400/AST2500.

To describe this properly, split out the AST2600 I2C binding into its
own YAML file. The compatible string remains unchanged.

The example section is updated to reflect the actual AST2600 SoC
register layout and interrupt configuration (aspeed-g6.dtsi,
lines 885-897):

- I2C bus and buffer register offsets
  - AST2600 I2C controller register base starts at 0x80, and the
    buffer region is located at 0xc00, per the AST2600 SoC register map.

- Interrupt configuration
  - AST2600 I2C controllers are connected to the ARM GIC, not the legacy
    internal interrupt controller.

Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
 .../bindings/i2c/aspeed,ast2600-i2c.yaml           | 62 ++++++++++++++++++++++
 .../devicetree/bindings/i2c/aspeed,i2c.yaml        |  3 +-
 2 files changed, 63 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
new file mode 100644
index 000000000000..077be85137c9
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/aspeed,ast2600-i2c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ASPEED I2C on the AST26XX SoCs
+
+maintainers:
+  - Ryan Chen <ryan_chen@aspeedtech.com>
+
+allOf:
+  - $ref: /schemas/i2c/i2c-controller.yaml#
+
+properties:
+  compatible:
+    enum:
+      - aspeed,ast2600-i2c-bus
+
+  reg:
+    items:
+      - description: controller registers
+      - description: controller buffer space
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-frequency:
+    description: Desired operating frequency of the I2C bus in Hz.
+    minimum: 500
+    maximum: 4000000
+    default: 100000
+
+  resets:
+    maxItems: 1
+
+required:
+  - reg
+  - compatible
+  - clocks
+  - resets
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/aspeed-clock.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    i2c@80 {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      compatible = "aspeed,ast2600-i2c-bus";
+      reg = <0x80 0x80>, <0xc00 0x20>;
+      clocks = <&syscon ASPEED_CLK_APB>;
+      resets = <&syscon ASPEED_RESET_I2C>;
+      clock-frequency = <100000>;
+      interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
+    };
diff --git a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
index 5b9bd2feda3b..d4e4f412feba 100644
--- a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
@@ -4,7 +4,7 @@
 $id: http://devicetree.org/schemas/i2c/aspeed,i2c.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: ASPEED I2C on the AST24XX, AST25XX, and AST26XX SoCs
+title: ASPEED I2C on the AST24XX, AST25XX SoCs
 
 maintainers:
   - Rayn Chen <rayn_chen@aspeedtech.com>
@@ -17,7 +17,6 @@ properties:
     enum:
       - aspeed,ast2400-i2c-bus
       - aspeed,ast2500-i2c-bus
-      - aspeed,ast2600-i2c-bus
 
   reg:
     minItems: 1

-- 
2.34.1