scsi: ufs: dt-bindings: add document for hisi-ufs

add ufs node document for Hisilicon.
Signed-off-by: NLi Wei <liwei213@huawei.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Tested-by: NJohn Stultz <john.stultz@linaro.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Documentation/devicetree/bindings/ufs/ufs-hisi.txt

+* Hisilicon Universal Flash Storage (UFS) Host Controller
+
+UFS nodes are defined to describe on-chip UFS hardware macro.
+Each UFS Host Controller should have its own node.
+
+Required properties:
+- compatible        : compatible list, contains one of the following -
+					"hisilicon,hi3660-ufs", "jedec,ufs-1.1" for hisi ufs
+					host controller present on Hi36xx chipset.
+- reg               : should contain UFS register address space & UFS SYS CTRL register address,
+- interrupt-parent  : interrupt device
+- interrupts        : interrupt number
+- clocks	        : List of phandle and clock specifier pairs
+- clock-names       : List of clock input name strings sorted in the same
+					order as the clocks property. "ref_clk", "phy_clk" is optional
+- freq-table-hz     : Array of <min max> operating frequencies stored in the same
+                      order as the clocks property. If this property is not
+                      defined or a value in the array is "0" then it is assumed
+                      that the frequency is set by the parent clock or a
+                      fixed rate clock source.
+- resets            : describe reset node register
+- reset-names       : reset node register, the "rst" corresponds to reset the whole UFS IP.
+
+Example:
+
+	ufs: ufs@ff3b0000 {
+		compatible = "hisilicon,hi3660-ufs", "jedec,ufs-1.1";
+		/* 0: HCI standard */
+		/* 1: UFS SYS CTRL */
+		reg = <0x0 0xff3b0000 0x0 0x1000>,
+			<0x0 0xff3b1000 0x0 0x1000>;
+		interrupt-parent = <&gic>;
+		interrupts = <GIC_SPI 278 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&crg_ctrl HI3660_CLK_GATE_UFSIO_REF>,
+			<&crg_ctrl HI3660_CLK_GATE_UFSPHY_CFG>;
+		clock-names = "ref_clk", "phy_clk";
+		freq-table-hz = <0 0>, <0 0>;
+		/* offset: 0x84; bit: 12  */
+		resets = <&crg_rst 0x84 12>;
+		reset-names = "rst";
+	};

Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt

@@ -41,6 +41,8 @@ Optional properties:
 -lanes-per-direction	: number of lanes available per direction - either 1 or 2.
 			  Note that it is assume same number of lanes is used both
 			  directions at once. If not specified, default is 2 lanes per direction.
+- resets            : reset node register
+- reset-names       : describe reset node register, the "rst" corresponds to reset the whole UFS IP.
 
 Note: If above properties are not defined it can be assumed that the supply
 regulators or clocks are always on.
@@ -61,9 +63,11 @@ Example:
 		vccq-max-microamp = 200000;
 		vccq2-max-microamp = 200000;
 
-		clocks = <&core 0>, <&ref 0>, <&iface 0>;
-		clock-names = "core_clk", "ref_clk", "iface_clk";
-		freq-table-hz = <100000000 200000000>, <0 0>, <0 0>;
+		clocks = <&core 0>, <&ref 0>, <&phy 0>, <&iface 0>;
+		clock-names = "core_clk", "ref_clk", "phy_clk", "iface_clk";
+		freq-table-hz = <100000000 200000000>, <0 0>, <0 0>, <0 0>;
+		resets = <&reset 0 1>;
+		reset-names = "rst";
 		phys = <&ufsphy1>;
 		phy-names = "ufsphy";
 	};