[PATCH v18 1/4] dt-bindings: add document of Rockchip power domains

[Caesar Wang <wxt@rock-chips.com>]

This add the necessary binding documentation for the power domains
found on Rockchip SoCs.

Signed-off-by: jinkun.hong <jinkun.hong@rock-chips.com>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>

---

Changes in v18:
- remove the notes of domains from dt-binding.

Changes in v17:
- add the decription in detail for RK3288 SoCs.

Changes in v16:
- remove the pmu node.

Changes in v15: None
Changes in v14: None
Changes in v13: None
Changes in v12: None
Changes in v11: None
Changes in v10: None
Changes in v9:
- add document decription.

Changes in v8:
- document go back to v2.

Changes in v7: None
Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v3:
- DT structure has changed.

Changes in v2:
- move clocks to "optional".

 .../bindings/soc/rockchip/power_domain.txt         | 46 ++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/rockchip/power_domain.txt

diff --git a/Documentation/devicetree/bindings/soc/rockchip/power_domain.txt b/Documentation/devicetree/bindings/soc/rockchip/power_domain.txt
new file mode 100644
index 0000000..4be3418
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/rockchip/power_domain.txt
@@ -0,0 +1,46 @@
+* Rockchip Power Domains
+
+Rockchip processors include support for multiple power domains which can be
+powered up/down by software based on different application scenes to save power.
+
+Required properties for power domain controller:
+- compatible: Should be one of the following.
+	"rockchip,rk3288-power-controller" - for RK3288 SoCs.
+- #power-domain-cells: Number of cells in a power-domain specifier.
+	Should be 1 for multiple PM domains.
+- #address-cells: Should be 1.
+- #size-cells: Should be 0.
+
+Required properties for power domain sub nodes:
+- reg: index of the power domain, should use macros in:
+	"include/dt-bindings/power-domain/rk3288.h" - for RK3288 type power domain.
+- clocks (optional): phandles to clocks which need to be enabled while power domain
+	switches state.
+
+Example:
+
+	power: power-controller {
+		compatible = "rockchip,rk3288-power-controller";
+		#power-domain-cells = <1>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		pd_gpu {
+			reg = <RK3288_PD_GPU>;
+			clocks = <&cru ACLK_GPU>;
+		};
+	};
+
+Node of a device using power domains must have a power-domains property,
+containing a phandle to the power device node and an index specifying which
+power domain to use.
+The index should use macros in:
+	"include/dt-bindings/power-domain/rk3288.h" - for rk3288 type power domain.
+
+Example of the node using power domain:
+
+	node {
+		/* ... */
+		power-domains = <&power RK3288_PD_GPU>;
+		/* ... */
+	};
-- 
1.9.1