Samsung S5P/EXYNOS SoC Camera Subsystem (FIMC)
----------------------------------------------

The S5P/Exynos SoC Camera subsystem comprises of multiple sub-devices
represented by separate device tree nodes. Currently this includes: FIMC (in
the S5P SoCs series known as CAMIF), MIPI CSIS, FIMC-LITE and FIMC-IS (ISP).

The sub-subdevices are defined as child nodes of the common 'camera' node which
also includes common properties of the whole subsystem not really specific to
any single sub-device, like common camera port pins or the CAMCLK clock outputs
for external image sensors attached to an SoC.

Common 'camera' node
--------------------

Required properties:

- compatible: must be "samsung,fimc", "simple-bus"
- clocks: list of clock specifiers, corresponding to entries in
  the clock-names property;
- clock-names : must contain "sclk_cam0", "sclk_cam1", "pxl_async0",
  "pxl_async1" entries, matching entries in the clocks property.

- #clock-cells: from the common clock bindings (../clock/clock-bindings.txt),
  must be 1. A clock provider is associated with the 'camera' node and it should
  be referenced by external sensors that use clocks provided by the SoC on
  CAM_*_CLKOUT pins. The clock specifier cell stores an index of a clock.
  The indices are 0, 1 for CAM_A_CLKOUT, CAM_B_CLKOUT clocks respectively.

- clock-output-names: from the common clock bindings, should contain names of
  clocks registered by the camera subsystem corresponding to CAM_A_CLKOUT,
  CAM_B_CLKOUT output clocks respectively.

The pinctrl bindings defined in ../pinctrl/pinctrl-bindings.txt must be used
to define a required pinctrl state named "default" and optional pinctrl states:
"idle", "active-a", active-b". These optional states can be used to switch the
camera port pinmux at runtime. The "idle" state should configure both the camera
ports A and B into high impedance state, especially the CAMCLK clock output
should be inactive. For the "active-a" state the camera port A must be activated
and the port B deactivated and for the state "active-b" it should be the other
way around.

The 'camera' node must include at least one 'fimc' child node.


'fimc' device nodes
-------------------

Required properties:

- compatible: "samsung,s5pv210-fimc" for S5PV210, "samsung,exynos4210-fimc"
  for Exynos4210 and "samsung,exynos4212-fimc" for Exynos4x12 SoCs;
- reg: physical base address and length of the registers set for the device;
- interrupts: should contain FIMC interrupt;
- clocks: list of clock specifiers, must contain an entry for each required
  entry in clock-names;
- clock-names: must contain "fimc", "sclk_fimc" entries.
- samsung,pix-limits: an array of maximum supported image sizes in pixels, for
  details refer to Table 2-1 in the S5PV210 SoC User Manual; The meaning of
  each cell is as follows:
  0 - scaler input horizontal size,
  1 - input horizontal size for the scaler bypassed,
  2 - REAL_WIDTH without input rotation,
  3 - REAL_HEIGHT with input rotation,
- samsung,sysreg: a phandle to the SYSREG node.

Each FIMC device should have an alias in the aliases node, in the form of
fimc<n>, where <n> is an integer specifying the IP block instance.

Optional properties:

- clock-frequency: maximum FIMC local clock (LCLK) frequency;
- samsung,min-pix-sizes: an array specyfing minimum image size in pixels at
  the FIMC input and output DMA, in the first and second cell respectively.
  Default value when this property is not present is <16 16>;
- samsung,min-pix-alignment: minimum supported image height alignment (first
  cell) and the horizontal image offset (second cell). The values are in pixels
  and default to <2 1> when this property is not present;
- samsung,mainscaler-ext: a boolean property indicating whether the FIMC IP
  supports extended image size and has CIEXTEN register;
- samsung,rotators: a bitmask specifying whether this IP has the input and
  the output rotator. Bits 4 and 0 correspond to input and output rotator
  respectively. If a rotator is present its corresponding bit should be set.
  Default value when this property is not specified is 0x11.
- samsung,cam-if: a bolean property indicating whether the IP block includes
  the camera input interface.
- samsung,isp-wb: this property must be present if the IP block has the ISP
  writeback input.
- samsung,lcd-wb: this property must be present if the IP block has the LCD
  writeback input.


'parallel-ports' node
---------------------

This node should contain child 'port' nodes specifying active parallel video
input ports. It includes camera A and camera B inputs. 'reg' property in the
port nodes specifies data input - 0, 1 indicates input A, B respectively.

Optional properties

- samsung,camclk-out (deprecated) : specifies clock output for remote sensor,
  0 - CAM_A_CLKOUT, 1 - CAM_B_CLKOUT;

Image sensor nodes
------------------

The sensor device nodes should be added to their control bus controller (e.g.
I2C0) nodes and linked to a port node in the csis or the parallel-ports node,
using the common video interfaces bindings, defined in video-interfaces.txt.

Example:

	aliases {
		fimc0 = &fimc_0;
	};

	/* Parallel bus IF sensor */
	i2c_0: i2c@13860000 {
		s5k6aa: sensor@3c {
			compatible = "samsung,s5k6aafx";
			reg = <0x3c>;
			vddio-supply = <...>;

			clock-frequency = <24000000>;
			clocks = <&camera 1>;
			clock-names = "mclk";

			port {
				s5k6aa_ep: endpoint {
					remote-endpoint = <&fimc0_ep>;
					bus-width = <8>;
					hsync-active = <0>;
					vsync-active = <1>;
					pclk-sample = <1>;
				};
			};
		};

		/* MIPI CSI-2 bus IF sensor */
		s5c73m3: sensor@1a {
			compatible = "samsung,s5c73m3";
			reg = <0x1a>;
			vddio-supply = <...>;

			clock-frequency = <24000000>;
			clocks = <&camera 0>;
			clock-names = "mclk";

			port {
				s5c73m3_1: endpoint {
					data-lanes = <1 2 3 4>;
					remote-endpoint = <&csis0_ep>;
				};
			};
		};
	};

	camera {
		compatible = "samsung,fimc", "simple-bus";
		clocks = <&clock 132>, <&clock 133>, <&clock 351>,
			 <&clock 352>;
		clock-names = "sclk_cam0", "sclk_cam1", "pxl_async0",
			      "pxl_async1";
		#clock-cells = <1>;
		clock-output-names = "cam_a_clkout", "cam_b_clkout";
		pinctrl-names = "default";
		pinctrl-0 = <&cam_port_a_clk_active>;
		#address-cells = <1>;
		#size-cells = <1>;

		/* parallel camera ports */
		parallel-ports {
			/* camera A input */
			port@0 {
				reg = <0>;
				fimc0_ep: endpoint {
					remote-endpoint = <&s5k6aa_ep>;
					bus-width = <8>;
					hsync-active = <0>;
					vsync-active = <1>;
					pclk-sample = <1>;
				};
			};
		};

		fimc_0: fimc@11800000 {
			compatible = "samsung,exynos4210-fimc";
			reg = <0x11800000 0x1000>;
			interrupts = <0 85 0>;
		};

		csis_0: csis@11880000 {
			compatible = "samsung,exynos4210-csis";
			reg = <0x11880000 0x1000>;
			interrupts = <0 78 0>;
			/* camera C input */
			port@3 {
				reg = <3>;
				csis0_ep: endpoint {
					remote-endpoint = <&s5c73m3_ep>;
					data-lanes = <1 2 3 4>;
					samsung,csis-hs-settle = <12>;
				};
			};
		};
	};

The MIPI-CSIS device binding is defined in samsung-mipi-csis.txt.
