soc: dt-bindings: add loongson-2 pm

Add the Loongson-2 SoC Power Management Controller binding with DT
schema format using json-schema.
Signed-off-by: Yinbo Zhu <zhuyinbo@loongson.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230803063703.5659-2-zhuyinbo@loongson.cnSigned-off-by: Arnd Bergmann <arnd@arndb.de>

Documentation/devicetree/bindings/soc/loongson/loongson,ls2k-pmc.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/loongson/loongson,ls2k-pmc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Loongson-2 Power Manager controller
+
+maintainers:
+  - Yinbo Zhu <zhuyinbo@loongson.cn>
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - loongson,ls2k0500-pmc
+          - loongson,ls2k1000-pmc
+      - const: syscon
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  loongson,suspend-address:
+    $ref: /schemas/types.yaml#/definitions/uint64
+    description:
+      The "loongson,suspend-address" is a deep sleep state (Suspend To
+      RAM) firmware entry address which was jumped from kernel and it's
+      value was dependent on specific platform firmware code. In
+      addition, the PM need according to it to indicate that current
+      SoC whether support Suspend To RAM.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    power-management@1fe27000 {
+        compatible = "loongson,ls2k1000-pmc", "syscon";
+        reg = <0x1fe27000 0x58>;
+        interrupt-parent = <&liointc1>;
+        interrupts = <11 IRQ_TYPE_LEVEL_LOW>;
+        loongson,suspend-address = <0x0 0x1c000500>;
+    };

MAINTAINERS

@@ -12282,6 +12282,12 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/hwinfo/loongson,ls2k-chipid.yaml
 F:	drivers/soc/loongson/loongson2_guts.c
 
+LOONGSON-2 SOC SERIES PM DRIVER
+M:	Yinbo Zhu <zhuyinbo@loongson.cn>
+L:	linux-pm@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/soc/loongson/loongson,ls2k-pmc.yaml
+
 LOONGSON-2 SOC SERIES PINCTRL DRIVER
 M:	zhanghongchen <zhanghongchen@loongson.cn>
 M:	Yinbo Zhu <zhuyinbo@loongson.cn>