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
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.
