Kernel-3.10.0-957.el7_samsung-fimc

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.
    

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, where 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 : 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.
The implementation of this bindings requires clock-frequency property to be
present in the sensor device nodes.

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 = <...>;
        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@0x1a {
    compatible = "samsung,s5c73m3";
    reg = <0x1a>;
    vddio-supply = <...>;

    clock-frequency = <24000000>;
    clocks = <...>;
    clock-names = "mclk";

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

camera {
    compatible = "samsung,fimc", "simple-bus";
    #address-cells = <1>;
    #size-cells = <1>;
    status = "okay";

    pinctrl-names = "default";
    pinctrl-0 = <&cam_port_a_clk_active>;

    /* 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>;
        status = "okay";
    };

    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.