dt-bindings: i2c: Add binding for Qualcomm CCI I2C controller

Add DT binding document for Qualcomm Camera Control Interface (CCI)
I2C controller.
Signed-off-by: Todor Tomov <todor.tomov@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Documentation/devicetree/bindings/i2c/i2c-qcom-cci.txt

+Qualcomm Camera Control Interface (CCI) I2C controller
+
+PROPERTIES:
+
+- compatible:
+	Usage: required
+	Value type: <string>
+	Definition: must be one of:
+		"qcom,msm8916-cci"
+		"qcom,msm8996-cci"
+		"qcom,sdm845-cci"
+
+- reg
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: base address CCI I2C controller and length of memory
+		    mapped region.
+
+- interrupts:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: specifies the CCI I2C interrupt. The format of the
+		    specifier is defined by the binding document describing
+		    the node's interrupt parent.
+
+- clocks:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: a list of phandle, should contain an entry for each
+		    entries in clock-names.
+
+- clock-names
+	Usage: required
+	Value type: <string>
+	Definition: a list of clock names, must include "cci" clock.
+
+- power-domains
+	Usage: required for "qcom,msm8996-cci"
+	Value type: <prop-encoded-array>
+	Definition:
+
+SUBNODES:
+
+The CCI provides I2C masters for one (msm8916) or two i2c busses (msm8996 and
+sdm845), described as subdevices named "i2c-bus@0" and "i2c-bus@1".
+
+PROPERTIES:
+
+- reg:
+	Usage: required
+	Value type: <u32>
+	Definition: Index of the CCI bus/master
+
+- clock-frequency:
+	Usage: optional
+	Value type: <u32>
+	Definition: Desired I2C bus clock frequency in Hz, defaults to 100
+		    kHz if omitted.
+
+Example:
+
+	cci@a0c000 {
+		compatible = "qcom,msm8996-cci";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0xa0c000 0x1000>;
+		interrupts = <GIC_SPI 295 IRQ_TYPE_EDGE_RISING>;
+		clocks = <&mmcc MMSS_MMAGIC_AHB_CLK>,
+			 <&mmcc CAMSS_TOP_AHB_CLK>,
+			 <&mmcc CAMSS_CCI_AHB_CLK>,
+			 <&mmcc CAMSS_CCI_CLK>,
+			 <&mmcc CAMSS_AHB_CLK>;
+		clock-names = "mmss_mmagic_ahb",
+			      "camss_top_ahb",
+			      "cci_ahb",
+			      "cci",
+			      "camss_ahb";
+
+		i2c-bus@0 {
+			reg = <0>;
+			clock-frequency = <400000>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+		};
+
+		i2c-bus@1 {
+			reg = <1>;
+			clock-frequency = <400000>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+		};
+	};