dt-bindings: power: Add Allwinner D1 PPU

The Allwinner D1 family of SoCs contain a PPU power domain controller
separate from the PRCM. It can power down the video engine and DSP, and
it contains special logic for hardware-assisted CPU idle. Other recent
Allwinner SoCs (e.g. TV303) have a PPU with a different set of domains.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20230126063419.15971-2-samuel@sholland.org
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Documentation/devicetree/bindings/power/allwinner,sun20i-d1-ppu.yaml

@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/allwinner,sun20i-d1-ppu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Allwinner SoCs PPU power domain controller
+
+maintainers:
+  - Samuel Holland <samuel@sholland.org>
+
+description:
+  D1 and related SoCs contain a power domain controller for the CPUs, GPU, and
+  video-related hardware.
+
+properties:
+  compatible:
+    enum:
+      - allwinner,sun20i-d1-ppu
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    description: Bus Clock
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  '#power-domain-cells':
+    const: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - resets
+  - '#power-domain-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/sun20i-d1-r-ccu.h>
+    #include <dt-bindings/reset/sun20i-d1-r-ccu.h>
+
+    ppu: power-controller@7001000 {
+        compatible = "allwinner,sun20i-d1-ppu";
+        reg = <0x7001000 0x1000>;
+        clocks = <&r_ccu CLK_BUS_R_PPU>;
+        resets = <&r_ccu RST_BUS_R_PPU>;
+        #power-domain-cells = <1>;
+    };

include/dt-bindings/power/allwinner,sun20i-d1-ppu.h

@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+
+#ifndef _DT_BINDINGS_POWER_SUN20I_D1_PPU_H_
+#define _DT_BINDINGS_POWER_SUN20I_D1_PPU_H_
+
+#define PD_CPU			0
+#define PD_VE			1
+#define PD_DSP			2
+
+#endif /* _DT_BINDINGS_POWER_SUN20I_D1_PPU_H_ */