media: dt-bindings: add bindings for i.MX7 media driver

Add bindings documentation for i.MX7 media drivers.
The imx7 MIPI CSI2 and imx7 CMOS Sensor Interface.
Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/devicetree/bindings/media/imx7-csi.txt

+Freescale i.MX7 CMOS Sensor Interface
+=====================================
+
+csi node
+--------
+
+This is device node for the CMOS Sensor Interface (CSI) which enables the chip
+to connect directly to external CMOS image sensors.
+
+Required properties:
+
+- compatible    : "fsl,imx7-csi";
+- reg           : base address and length of the register set for the device;
+- interrupts    : should contain CSI interrupt;
+- clocks        : list of clock specifiers, see
+        Documentation/devicetree/bindings/clock/clock-bindings.txt for details;
+- clock-names   : must contain "axi", "mclk" and "dcic" entries, matching
+                 entries in the clock property;
+
+The device node shall contain one 'port' child node with one child 'endpoint'
+node, according to the bindings defined in:
+Documentation/devicetree/bindings/media/video-interfaces.txt.
+
+In the following example a remote endpoint is a video multiplexer.
+
+example:
+
+                csi: csi@30710000 {
+                        #address-cells = <1>;
+                        #size-cells = <0>;
+
+                        compatible = "fsl,imx7-csi";
+                        reg = <0x30710000 0x10000>;
+                        interrupts = <GIC_SPI 7 IRQ_TYPE_LEVEL_HIGH>;
+                        clocks = <&clks IMX7D_CLK_DUMMY>,
+                                        <&clks IMX7D_CSI_MCLK_ROOT_CLK>,
+                                        <&clks IMX7D_CLK_DUMMY>;
+                        clock-names = "axi", "mclk", "dcic";
+
+                        port {
+                                csi_from_csi_mux: endpoint {
+                                        remote-endpoint = <&csi_mux_to_csi>;
+                                };
+                        };
+                };

Documentation/devicetree/bindings/media/imx7-mipi-csi2.txt

+Freescale i.MX7 Mipi CSI2
+=========================
+
+mipi_csi2 node
+--------------
+
+This is the device node for the MIPI CSI-2 receiver core in i.MX7 SoC. It is
+compatible with previous version of Samsung D-phy.
+
+Required properties:
+
+- compatible    : "fsl,imx7-mipi-csi2";
+- reg           : base address and length of the register set for the device;
+- interrupts    : should contain MIPI CSIS interrupt;
+- clocks        : list of clock specifiers, see
+        Documentation/devicetree/bindings/clock/clock-bindings.txt for details;
+- clock-names   : must contain "pclk", "wrap" and "phy" entries, matching
+                  entries in the clock property;
+- power-domains : a phandle to the power domain, see
+          Documentation/devicetree/bindings/power/power_domain.txt for details.
+- reset-names   : should include following entry "mrst";
+- resets        : a list of phandle, should contain reset entry of
+                  reset-names;
+- phy-supply    : from the generic phy bindings, a phandle to a regulator that
+	          provides power to MIPI CSIS core;
+
+Optional properties:
+
+- clock-frequency : The IP's main (system bus) clock frequency in Hz, default
+		    value when this property is not specified is 166 MHz;
+- fsl,csis-hs-settle : differential receiver (HS-RX) settle time;
+
+The device node should contain two 'port' child nodes with one child 'endpoint'
+node, according to the bindings defined in:
+ Documentation/devicetree/bindings/ media/video-interfaces.txt.
+ The following are properties specific to those nodes.
+
+port node
+---------
+
+- reg		  : (required) can take the values 0 or 1, where 0 shall be
+                     related to the sink port and port 1 shall be the source
+                     one;
+
+endpoint node
+-------------
+
+- data-lanes    : (required) an array specifying active physical MIPI-CSI2
+		    data input lanes and their mapping to logical lanes; this
+                    shall only be applied to port 0 (sink port), the array's
+                    content is unused only its length is meaningful,
+                    in this case the maximum length supported is 2;
+
+example:
+
+        mipi_csi: mipi-csi@30750000 {
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                compatible = "fsl,imx7-mipi-csi2";
+                reg = <0x30750000 0x10000>;
+                interrupts = <GIC_SPI 25 IRQ_TYPE_LEVEL_HIGH>;
+                clocks = <&clks IMX7D_IPG_ROOT_CLK>,
+                                <&clks IMX7D_MIPI_CSI_ROOT_CLK>,
+                                <&clks IMX7D_MIPI_DPHY_ROOT_CLK>;
+                clock-names = "pclk", "wrap", "phy";
+                clock-frequency = <166000000>;
+                power-domains = <&pgc_mipi_phy>;
+                phy-supply = <&reg_1p0d>;
+                resets = <&src IMX7_RESET_MIPI_PHY_MRST>;
+                reset-names = "mrst";
+                fsl,csis-hs-settle = <3>;
+
+                port@0 {
+                        reg = <0>;
+
+                        mipi_from_sensor: endpoint {
+                                remote-endpoint = <&ov2680_to_mipi>;
+                                data-lanes = <1>;
+                        };
+                };
+
+                port@1 {
+                        reg = <1>;
+
+                        mipi_vc0_to_csi_mux: endpoint {
+                                remote-endpoint = <&csi_mux_from_mipi_vc0>;
+                        };
+                };
+        };