dt-bindings: clock: Document Renesas R-Car X5H Clock Pulse Generator

Document support for the Renesas R-Car X5H Clock Pulse Generator, and
add binding definitions for a limited initial set of clocks.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Tested-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/7a33c99816c850faeec5c17532811faf78959a1d.1785941595.git.geert+renesas@glider.be

Documentation/devicetree/bindings/clock/renesas,r8a78000-cpg.yaml

@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/renesas,r8a78000-cpg.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas R-Car X5H Clock Pulse Generator
+
+maintainers:
+  - Geert Uytterhoeven <geert+renesas@glider.be>
+
+description:
+  The R-Car X5H Clock Pulse Generator (CLK CONTROL) consists of oscillators,
+  PLL circuits, clock dividers and clock control circuits.  It provides various
+  clocks for other modules.
+
+properties:
+  compatible:
+    const: renesas,r8a78000-cpg
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 2
+
+  clock-names:
+    items:
+      - const: extal
+      - const: extalr
+
+  '#clock-cells':
+    description:
+      The single clock specifier cell must be the clock number, as defined in
+      <dt-bindings/clock/renesas,r8a78000-cpg.h>.
+    const: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - '#clock-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    clock-controller@c1320000 {
+            compatible = "renesas,r8a78000-cpg";
+            reg = <0xc1320000 0x10000>;
+            clocks = <&extal_clk>, <&extalr_clk>;
+            clock-names = "extal", "extalr";
+            #clock-cells = <1>;
+    };

include/dt-bindings/clock/renesas,r8a78000-cpg.h

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/*
+ * Copyright (C) 2026 Glider bv
+ */
+#ifndef __DT_BINDINGS_CLOCK_RENESAS_R8A78000_CPG_H__
+#define __DT_BINDINGS_CLOCK_RENESAS_R8A78000_CPG_H__
+
+/* R-Car X5H Clock Pulse Generator Clocks */
+
+#define R8A78000_CPG_SGASYNCD4_PERW_BUS		0
+#define R8A78000_CPG_SGASYNCD8_PERW_BUS		1
+#define R8A78000_CPG_SGASYNCD16_PERW_BUS	2
+
+#endif /* __DT_BINDINGS_CLOCK_RENESAS_R8A78000_CPG_H__ */