ahci: st: Provide DT bindings for ST's SATA implementation

Cc: devicetree@vger.kernel.org
Cc: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Acked-by: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

Documentation/devicetree/bindings/ata/ahci-st.txt

+STMicroelectronics STi SATA controller
+
+This binding describes a SATA device.
+
+Required properties:
+ - compatible	   : Must be "st,sti-ahci"
+ - reg		   : Physical base addresses and length of register sets
+ - interrupts	   : Interrupt associated with the SATA device
+ - interrupt-names :   Associated name must be; "hostc"
+ - resets	   : The power-down and soft-reset lines of SATA IP
+ - reset-names	   :   Associated names must be; "pwr-dwn" and "sw-rst"
+ - clocks	   : The phandle for the clock
+ - clock-names	   :   Associated name must be; "ahci_clk"
+ - phys		   : The phandle for the PHY device
+ - phy-names	   :   Associated name must be; "ahci_phy"
+
+Example:
+
+	sata0: sata@fe380000 {
+		compatible      = "st,sti-ahci";
+		reg             = <0xfe380000 0x1000>;
+		interrupts      = <GIC_SPI 157 IRQ_TYPE_NONE>;
+		interrupt-names = "hostc";
+		phys	        = <&miphy365x_phy MIPHY_PORT_0 MIPHY_TYPE_SATA>;
+		phy-names       = "ahci_phy";
+		resets	        = <&powerdown STIH416_SATA0_POWERDOWN>,
+				  <&softreset STIH416_SATA0_SOFTRESET>;
+		reset-names     = "pwr-dwn", "sw-rst";
+		clocks	        = <&clk_s_a0_ls CLK_ICN_REG>;
+		clock-names     = "ahci_clk";
+	};