[PATCH v4] dt-bindings: rtc: epson,rx6110: Convert to DT Schema

[Udaya Kiran Challa <challauday369@gmail.com>]

Convert the Epson RX6110 Real Time Clock devicetree binding
from the legacy text format to DT schema.

Signed-off-by: Udaya Kiran Challa <challauday369@gmail.com>
---
Changelog:
Changes since v3:
- Add conditional validation for SPI mode properties using anyOf

Link to v3:https://lore.kernel.org/all/20260509181909.21871-1-challauday369@gmail.com/

Changes since v2:
- Reference rtc.yaml for common RTC properties
- Add conditional validation for SPI mode properties

Link to v2:https://lore.kernel.org/all/20260509095713.5818-1-challauday369@gmail.com/

Changes since v1:
- Reuse common SPI peripheral properties
- Drop redundant SPI-specific comment
- Remove unused labels from examples

Link to v1:https://lore.kernel.org/all/20260504183728.27412-1-challauday369@gmail.com/
---
 .../devicetree/bindings/rtc/epson,rx6110.txt  | 39 ---------
 .../devicetree/bindings/rtc/epson,rx6110.yaml | 79 +++++++++++++++++++
 2 files changed, 79 insertions(+), 39 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/rtc/epson,rx6110.txt
 create mode 100644 Documentation/devicetree/bindings/rtc/epson,rx6110.yaml

diff --git a/Documentation/devicetree/bindings/rtc/epson,rx6110.txt b/Documentation/devicetree/bindings/rtc/epson,rx6110.txt
deleted file mode 100644
index 3dc313e01f77..000000000000
--- a/Documentation/devicetree/bindings/rtc/epson,rx6110.txt
+++ /dev/null
@@ -1,39 +0,0 @@
-Epson RX6110 Real Time Clock
-============================
-
-The Epson RX6110 can be used with SPI or I2C busses. The kind of
-bus depends on the SPISEL pin and can not be configured via software.
-
-I2C mode
---------
-
-Required properties:
-  - compatible: should be: "epson,rx6110"
-  - reg : the I2C address of the device for I2C
-
-Example:
-
-	rtc: rtc@32 {
-		compatible = "epson,rx6110"
-		reg = <0x32>;
-	};
-
-SPI mode
---------
-
-Required properties:
-  - compatible: should be: "epson,rx6110"
-  - reg: chip select number
-  - spi-cs-high: RX6110 needs chipselect high
-  - spi-cpha: RX6110 works with SPI shifted clock phase
-  - spi-cpol: RX6110 works with SPI inverse clock polarity
-
-Example:
-
-	rtc: rtc@3 {
-		compatible = "epson,rx6110"
-		reg = <3>
-		spi-cs-high;
-		spi-cpha;
-		spi-cpol;
-	};
diff --git a/Documentation/devicetree/bindings/rtc/epson,rx6110.yaml b/Documentation/devicetree/bindings/rtc/epson,rx6110.yaml
new file mode 100644
index 000000000000..3466f74736d2
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/epson,rx6110.yaml
@@ -0,0 +1,79 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/epson,rx6110.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Epson RX6110 Real Time Clock
+
+description: |
+  The Epson RX6110 can be used with SPI or I2C busses.
+  The kind of bus depends on the SPISEL pin and can not be
+  configured via software.
+
+maintainers:
+  - Alexandre Belloni <alexandre.belloni@bootlin.com>
+
+allOf:
+  - $ref: rtc.yaml#
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    const: epson,rx6110
+
+  reg:
+    maxItems: 1
+
+  spi-cs-high: true
+  spi-cpha: true
+  spi-cpol: true
+
+required:
+  - compatible
+  - reg
+
+if:
+  anyOf:
+    - required:
+        - spi-cs-high
+    - required:
+        - spi-cpha
+    - required:
+        - spi-cpol
+
+then:
+  required:
+    - spi-cs-high
+    - spi-cpha
+    - spi-cpol
+
+unevaluatedProperties: false
+
+examples:
+  # I2C mode
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      rtc@32 {
+        compatible = "epson,rx6110";
+        reg = <0x32>;
+      };
+    };
+
+  # SPI mode
+  - |
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      rtc@3 {
+        compatible = "epson,rx6110";
+        reg = <3>;
+        spi-cs-high;
+        spi-cpha;
+        spi-cpol;
+      };
+    };
-- 
2.43.0