[PATCH] dt-bindings: mfd: Add Renesas R2A11302FT PMIC

[Wolfram Sang <wsa+renesas@sang-engineering.com>]

This PMIC is referenced in upstream DTs for the Renesas Lager and
Koelsch boards. Sadly, we don't have documentation for more complete
bindings, but due to the spi-cpol/cpha it also doesn't belong to trivial
devices. So, start with this minimal binding description with the facts
that we do know:

Fixes:
arch/arm/boot/dts/renesas/r8a7790-lager.dtb: /soc/spi@e6e10000/pmic@0: failed to match any schema with compatible: ['renesas,r2a11302ft']
arch/arm/boot/dts/renesas/r8a7791-koelsch.dtb: /soc/spi@e6e20000/pmic@0: failed to match any schema with compatible: ['renesas,r2a11302ft']

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

Change since RFC [1]:
* dropped "unevaluatedProperties" because we know this binding is not
  complete currently
* removed 'pmic' label from the example
* proper patch description

[1] https://lore.kernel.org/r/20250929083449.14393-1-wsa+renesas@sang-engineering.com

 .../bindings/mfd/renesas,r2a11302ft.yaml      | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/renesas,r2a11302ft.yaml

diff --git a/Documentation/devicetree/bindings/mfd/renesas,r2a11302ft.yaml b/Documentation/devicetree/bindings/mfd/renesas,r2a11302ft.yaml
new file mode 100644
index 000000000000..e978b359b3ec
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/renesas,r2a11302ft.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/renesas,r2a11302ft.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas R2A11302FT Power Supply ICs for R-Car
+
+maintainers:
+  - Wolfram Sang <wsa+renesas@sang-engineering.com>
+
+properties:
+  compatible:
+    const: renesas,r2a11302ft
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency:
+    maximum: 6000000
+
+  spi-cpol: true
+
+  spi-cpha: true
+
+required:
+  - compatible
+  - reg
+  - spi-cpol
+  - spi-cpha
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+examples:
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        pmic@0 {
+                compatible = "renesas,r2a11302ft";
+                reg = <0>;
+                spi-max-frequency = <6000000>;
+                spi-cpol;
+                spi-cpha;
+        };
+    };
+...
-- 
2.47.2