In this guide, we will step-by-step guide you to use video camera IMX708 on SP7350 platforms.
1 IMX708 specification
Back-illuminated and stacked CMOS 12-megapixel image sensor
Pixel Size: 1.4 x 1.4 μm
HorizoHorizontal/vertical: 4608 × 2592 pixels
Sensor size: 7.4mm sensor diagonal
Optical size: 1/2.43"
Maximum exposure times (seconds): 112
HDR mode (up to 3 megapixel output)
video modes: 2304 × 1296p56, 2304 × 1296p30 HDR, 1536 × 864p120
2 Setup
2.1 Enable IMX708 in kernel configuration
1 Enter kernel configuration
cd ./linux/kernel make menuconfig
2 Selects submenus: Device Drivers>Multimedia support>Media ancillary drivers>Camera sensor devices
3 Select Sony IMX708 sensor support and pressing <Y> inlucdes. Then save and exit.
2.2 Modify device tree source
Device-tree source files of SP7350 are located in linux/kernel/arch/arm64/boot/dts/sunplus/.
Here lists all files for SP7350 boards:
Boards | Device-tree source files |
C3V-W EVB | sp7350-ev.dts |
Modify device tree source file to define IMX708 source for driver
2.2.1 Using SP7350 MIPI-CSI-RX4
Open IMX708_IN4 macro to add IMX708 node and link mipicsirx4.
2.2.2 Using SP7350 other MIPI-CSI-RX
Define IMX708 node in i2c node:
i2c {
#address-cells = <1>;
#size-cells = <0>;
imx708: imx708@1a {
compatible = "sony,imx708";
reg = <0x1a>;
clocks = <&imx708_clk>;
clock-names = "inclk";
vana1-supply = <&imx708_vana1_2v8>; /* 2.8v */
vana2-supply = <&imx708_vana2_1v8>;/* 1.8v */
vdig-supply = <&imx708_vdig_1v1>; /* 1.1v */
vddl-supply = <&imx708_vddl_1v8>; /* 1.8v */
port {
imx708_ep: endpoint {
remote-endpoint = <&csi_ep>;
data-lanes = <1 2>;
clock-noncontinuous;
link-frequencies = /bits/ 64 <450000000>;
};
};
};
};
port: Should contain one endpoint sub-node used to model connection to the video receiver according to the specification defined in Documentation/devicetree/bindings/media/video-interfaces.txt.
Video receiver endpoint sub-node should defined in mipicsirx node. For example:
mipicsirx: csirx@f8005480 {
port@0 {
reg = <0>;
/* MIPI CSI-2 bus endpoint */
csi_ep: endpoint {
remote-endpoint = <&imx708_ep>;
bus-type = <4>;
clock-lanes = <0>;
data-lanes = <1 2>;
};
};
2.3 Compile and burn
2.4 Connect sensor module
Using C3V-W board MIPI-CSI-RX4, as follows：
2.5 Check
After the burning is completed, start the board. The system should print the following information through the serial port.
[ 2.121010] i2c /dev entries driver [ 2.133944] imx708 0-001a: camera module ID 0x0301 [ 2.173080] sp-csi2 f8005480.csirx: 2 lanes found [ 2.173479] sp-vin f8005980.video: assigned reserved memory node mipicsirx@4f600000 [ 2.177650] imx708 0-001a: Consider updating driver imx708 to match on endpoints [ 2.185261] sp-vin f8005980.video: Device VIN8 registered as video0 [ 2.191230] sp-vin f8005980.video: SP VIN driver probed
After the system startup is completed, the video device can be viewed.
root@dbv3:~# ls /dev/video0 /dev/video0
3 Test
3.1 V4l2-ctl command
This command is used to control V4L2 devices from the command line. It allows you to query device capabilities, set device parameters, and capture video and still image.
Use v4l2-ctl --all --device /dev/video0 command getting device all information.
root@dbv3:~# v4l2-ctl --all --device /dev/video0
Driver Info:
Driver name : sp_vin
Card type : SP_VIN
Bus info : platform:f8005980.video
Driver version : 5.10.201
Capabilities : 0xa5200001
Video Capture
Read/Write
Streaming
Extended Pix Format
Device Capabilities
Device Caps : 0x25200001
Video Capture
Read/Write
Streaming
Extended Pix Format
Media Driver Info:
Driver name : sp_vin
Model : sunplus,sp7350-vin
Serial :
Bus info : platform:f8005980.video
Media version : 5.10.201
Hardware revision: 0x00000000 (0)
Driver version : 5.10.201
Entity Info:
ID : 16
Name : VIN8 output
Type : V4L2 I/O
Pad : 0: Sink
Priority: 2
Video input : 0 (VIN8 output: ok)
Format Video Capture:
Width/Height : 1536/864
Pixel Format : 'RG10' (10-bit Bayer RGRG/GBGB)
Field : None
Bytes per Line : 3072
Size Image : 2654208
Colorspace : Raw
Transfer Function : None
YCbCr/HSV Encoding: ITU-R 601
Quantization : Full Range
Flags :
User Controls
exposure 0x00980911 (int) : min=1 max=2602 step=1 default=1600 value=1600
horizontal_flip 0x00980914 (bool) : default=0 value=0 flags=modify-layout
vertical_flip 0x00980915 (bool) : default=0 value=0 flags=modify-layout
alpha_component 0x00980929 (int) : min=0 max=255 step=1 default=255 value=255
Camera Controls
wide_dynamic_range 0x009a0915 (bool) : default=0 value=0 flags=modify-layout
Image Source Controls
vertical_blanking 0x009e0901 (int) : min=40 max=8387616 step=1 default=2755 value=58
horizontal_blanking 0x009e0902 (int) : min=3680 max=3680 step=1 default=3680 value=3680 flags=read-only
analogue_gain 0x009e0903 (int) : min=112 max=960 step=1 default=112 value=112
red_pixel_value 0x009e0904 (int) : min=0 max=4095 step=1 default=4095 value=4095
green_red_pixel_value 0x009e0905 (int) : min=0 max=4095 step=1 default=4095 value=4095
blue_pixel_value 0x009e0906 (int) : min=0 max=4095 step=1 default=4095 value=4095
green_blue_pixel_value 0x009e0907 (int) : min=0 max=4095 step=1 default=4095 value=4095
notify_gains 0x009e0909 (u32) : min=1 max=65535 step=1 default=256 [4] flags=has-payload
Image Processing Controls
link_frequency 0x009f0901 (intmenu): min=0 max=0 default=0 value=0 flags=read-only
pixel_rate 0x009f0902 (int64) : min=566400000 max=566400000 step=1 default=566400000 value=566400000 flags=read-only
test_pattern 0x009f0903 (menu) : min=0 max=4 default=0 value=0
digital_gain 0x009f0905 (int) : min=256 max=65535 step=1 default=256 value=256
3.2 Capture image
3.2.1 Config video device
Use v4l2-ctl -d /dev/video0 --set-ctrl params=value setting device controls.
set exposure(exposure 0x00980911 (int) : min=1 max=2602 step=1 default=1600 value=1600):
v4l2-ctl -d /dev/video0 --set-ctrl exposure=2000
set analogue_gain(analogue_gain 0x009e0903 (int): min=112 max=960 step=1 default=112 value=112)
v4l2-ctl -d /dev/video0 --set-ctrl analogue_gain=800
set digital_gain(digital_gain 0x009f0905 (int) : min=256 max=65535 step=1 default=256 value=256)
v4l2-ctl -d /dev/video0 --set-ctrl digital_gain=550
Change image brightness by changing the exposure, analogue_gain and digital_gain.
3.2.2 Capture
Use v4l2-ctl --list-formats-ext --device /dev/video0 querying device video format.
root@dbv3:~# v4l2-ctl --list-formats-ext --device /dev/video0 ioctl: VIDIOC_ENUM_FMT Type: Video Capture [0]: 'RG10' (10-bit Bayer RGRG/GBGB) Size: Discrete 4608x2592 Size: Discrete 2304x1296 Size: Discrete 1536x864 [1]: 'pRAA' (10-bit Bayer RGRG/GBGB Packed) Size: Discrete 4608x2592 Size: Discrete 2304x1296 Size: Discrete 1536x864
Use v4l2-ctl --stream capture image.
v4l2-ctl -d /dev/video0 --set-fmt-video=width=2304,height=1296,pixelformat=pRAA --stream-mmap=3 --stream-to=/home/root/imx708.raw --stream-skip=9 --stream-count=1
--set-fmt-video=width=2304,height=1296,pixelformat=pRAA set image format
--stream-count <count> stream <count> buffers. The default is to keep streaming forever. This count does not include the number of initial skipped buffers as is passed by --stream-skip.
--stream-skip <count> skip the first <count> buffers. The default is 0.
--stream-to <file> stream to this file. The default is to discard the data. If <file> is '-', then the data is written to stdout and the --silent option is turned on automatically.
--stream-mmap <count> capture video using mmap() [VIDIOC_(D)QBUF] count: the number of buffers to allocate. The default is 3.
After executing the capture command, the stream data is written to /home/root/imx708.raw.
3.3 Display image raw data
3.3.1 Download and install raw image viewer
Download raw image viewer from PixelViewer | Carina Studio. And PixelViewer is an open source project based cross-platform image which viewer supports reading raw Luminance/YUV/RGB/ARGB/Bayer pixels data from file and rendering it.
3.3.2 Use pixel viewer open image
Config render params by 3.2.2 v4l2-ctl capture command
3.3 HDR
Enable HDR
v4l2-ctl -d /dev/video0 --set-ctrl wide_dynamic_range=1
capture image
v4l2-ctl -d /dev/video0 --set-fmt-video=width=2304,height=1296,pixelformat=pRAA --stream-mmap=3 --stream-to=/home/root/imx708_hdr.raw --stream-skip=9 --stream-count=1
image render：
comparison：
By comparing the brightness of the light position, it can be seen that HDR improves the image effect。