diff --git a/Documentation/devicetree/bindings/power/renesas,rcar-sysc.yaml b/Documentation/devicetree/bindings/power/renesas,rcar-sysc.yaml
index b67aa170b2c1..68b4696d7c59 100644
--- a/Documentation/devicetree/bindings/power/renesas,rcar-sysc.yaml
+++ b/Documentation/devicetree/bindings/power/renesas,rcar-sysc.yaml
@@ -13,8 +13,11 @@ maintainers:
 description: |
   The R-Car (RZ/G) System Controller provides power management for the CPU
   cores and various coprocessors.
-  The power domain IDs for consumers are defined in header files:
-  include/dt-bindings/power/r8*-sysc.h
+  The power domain IDs for consumers are defined in the below header files
+  (where the asterisk serves as a wildcard matching the specific SoC
+  identifier):
+  include/dt-bindings/power/r8*-sysc.h or
+  include/dt-bindings/power/renesas,r8*-sysc.h
 
 properties:
   compatible:
diff --git a/include/dt-bindings/power/renesas,r8a774a3-sysc.h b/include/dt-bindings/power/renesas,r8a774a3-sysc.h
new file mode 100644
index 000000000000..ddee6812e9a4
--- /dev/null
+++ b/include/dt-bindings/power/renesas,r8a774a3-sysc.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/*
+ * Copyright (C) 2026 Renesas Electronics Corp.
+ */
+#ifndef __DT_BINDINGS_POWER_RENESAS_R8A774A3_SYSC_H__
+#define __DT_BINDINGS_POWER_RENESAS_R8A774A3_SYSC_H__
+
+/*
+ * These power domain indices match the numbers of the interrupt bits
+ * representing the power areas in the various Interrupt Registers
+ * (e.g. SYSCISR, Interrupt Status Register)
+ */
+
+#define R8A774A3_PD_CA57_CPU0		 0
+#define R8A774A3_PD_CA57_CPU1		 1
+#define R8A774A3_PD_CA53_CPU0		 5
+#define R8A774A3_PD_CA53_CPU1		 6
+#define R8A774A3_PD_CA53_CPU2		 7
+#define R8A774A3_PD_CA53_CPU3		 8
+#define R8A774A3_PD_CA57_SCU		12
+#define R8A774A3_PD_A3VC		14
+#define R8A774A3_PD_3DG_A		17
+#define R8A774A3_PD_3DG_B		18
+#define R8A774A3_PD_CA53_SCU		21
+#define R8A774A3_PD_A2VC1		26
+
+/* Always-on power area */
+#define R8A774A3_PD_ALWAYS_ON		32
+
+#endif /* __DT_BINDINGS_POWER_RENESAS_R8A774A3_SYSC_H__ */