[PATCH v5 1/2] media: dt-bindings: media: xilinx: Add Xilinx MIPI CSI-2 Rx Subsystem

[Vishal Sagar]

Add bindings documentation for Xilinx MIPI CSI-2 Rx Subsystem.

The Xilinx MIPI CSI-2 Rx Subsystem consists of a CSI-2 Rx controller, a
DPHY in Rx mode, an optional I2C controller and a Video Format Bridge.

Signed-off-by: Vishal Sagar <vishal.sagar@xxxxxxxxxx>
Reviewed-by: Hyun Kwon <hyun.kwon@xxxxxxxxxx>
---
v5
- Incorporated comments by Luca Cersoli
- Removed DPHY clock from description and example
- Removed bayer pattern from device tree MIPI CSI IP
  doesn't deal with bayer pattern.

v4
- Added reviewed by Hyun Kwon

v3
- removed interrupt parent as suggested by Rob
- removed dphy clock
- moved vfb to optional properties
- Added required and optional port properties section
- Added endpoint property section

v2
- updated the compatible string to latest version supported
- removed DPHY related parameters
- added CSI v2.0 related property (including VCX for supporting upto 16
  virtual channels).
- modified csi-pxl-format from string to unsigned int type where the value
  is as per the CSI specification
- Defined port 0 and port 1 as sink and source ports.
- Removed max-lanes property as suggested by Rob and Sakari

 .../bindings/media/xilinx/xlnx,csi2rxss.txt        | 118 +++++++++++++++++++++
 1 file changed, 118 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/xilinx/xlnx,csi2rxss.txt

diff --git a/Documentation/devicetree/bindings/media/xilinx/xlnx,csi2rxss.txt b/Documentation/devicetree/bindings/media/xilinx/xlnx,csi2rxss.txt
new file mode 100644
index 0000000..cdf07c61
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/xilinx/xlnx,csi2rxss.txt
@@ -0,0 +1,118 @@
+Xilinx MIPI CSI2 Receiver Subsystem Device Tree Bindings
+--------------------------------------------------------
+
+The Xilinx MIPI CSI2 Receiver Subsystem is used to capture MIPI CSI2 traffic
+from compliant camera sensors and send the output as AXI4 Stream video data
+for image processing.
+
+The subsystem consists of a MIPI DPHY in slave mode which captures the
+data packets. This is passed along the MIPI CSI2 Rx IP which extracts the
+packet data. The optional Video Format Bridge (VFB) converts this data to
+AXI4 Stream video data.
+
+For more details, please refer to PG232 Xilinx MIPI CSI-2 Receiver Subsystem.
+
+Required properties:
+--------------------
+- compatible: Must contain "xlnx,mipi-csi2-rx-subsystem-4.0".
+- reg: Physical base address and length of the registers set for the device.
+- interrupts: Property with a value describing the interrupt number.
+- clocks: List of phandles to AXI Lite and Video clocks.
+- clock-names: Must contain "lite_aclk" and "video_aclk" in the same order
+  as clocks listed in clocks property.
+- xlnx,csi-pxl-format: This denotes the CSI Data type selected in hw design.
+  Packets other than this data type (except for RAW8 and User defined data
+  types) will be filtered out. Possible values are as below -
+  0x1E - YUV4228B
+  0x1F - YUV42210B
+  0x20 - RGB444
+  0x21 - RGB555
+  0x22 - RGB565
+  0x23 - RGB666
+  0x24 - RGB888
+  0x28 - RAW6
+  0x29 - RAW7
+  0x2A - RAW8
+  0x2B - RAW10
+  0x2C - RAW12
+  0x2D - RAW14
+  0x2E - RAW16
+  0x2F - RAW20
+
+
+Optional properties:
+--------------------
+- xlnx,vfb: This is present when Video Format Bridge is enabled.
+  Without this property the driver won't be loaded as IP won't be able to generate
+  media bus format compliant stream output.
+- xlnx,en-csi-v2-0: Present if CSI v2 is enabled in IP configuration.
+- xlnx,en-vcx: When present, there are maximum 16 virtual channels, else
+  only 4. This is present only if xlnx,en-csi-v2-0 is present.
+- xlnx,en-active-lanes: present if the number of active lanes can be
+  reconfigured at runtime in the Protocol Configuration Register.
+  If present, the V4L2_CID_XILINX_MIPICSISS_ACT_LANES is added.
+  Otherwise all lanes, as set in IP configuration, are always active.
+
+Ports
+-----
+The device node shall contain two 'port' child nodes as defined in
+Documentation/devicetree/bindings/media/video-interfaces.txt.
+
+The port@0 is a sink port and shall connect to CSI2 source like camera.
+It must have the data-lanes property.
+
+The port@1 is a source port and can be connected to any video processing IP
+which can work with AXI4 Stream data.
+
+Required port properties:
+--------------------
+- reg: 0 - for sink port.
+       1 - for source port.
+
+Optional endpoint property:
+---------------------------
+- data-lanes: specifies MIPI CSI-2 data lanes as covered in video-interfaces.txt.
+  This should be in the sink port endpoint which connects to MIPI CSI2 source
+  like sensor. The possible values are:
+  1       - For 1 lane enabled in IP.
+  1 2     - For 2 lanes enabled in IP.
+  1 2 3   - For 3 lanes enabled in IP.
+  1 2 3 4 - For 4 lanes enabled in IP.
+
+Example:
+
+	csiss_1: csiss@a0020000 {
+		compatible = "xlnx,mipi-csi2-rx-subsystem-4.0";
+		reg = <0x0 0xa0020000 0x0 0x10000>;
+		interrupt-parent = <&gic>;
+		interrupts = <0 95 4>;
+		xlnx,csi-pxl-format = <0x2a>;
+		xlnx,vfb;
+		xlnx,en-active-lanes;
+		xlnx,en-csi-v2-0;
+		xlnx,en-vcx;
+		clock-names = "lite_aclk", "video_aclk";
+		clocks = <&misc_clk_0>, <&misc_clk_1>;
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port@0 {
+				/* Sink port */
+				reg = <0>;
+				csiss_in: endpoint {
+					data-lanes = <1 2 3 4>;
+					/* MIPI CSI2 Camera handle */
+					remote-endpoint = <&camera_out>;
+				};
+			};
+			port@1 {
+				/* Source port */
+				reg = <1>;
+				csiss_out: endpoint {
+					remote-endpoint = <&vproc_in>;
+				};
+			};
+		};
+	};
-- 
2.7.4