Table of Contents
IntroductionThe Xilinx UHD SDI Rx Subsystem consists of UHD SDI Rx IP core, an SDI to native video bridge followed by a Native to AXI-4 S bridge. It is capable of detecting the SD, HD, 3GA, 3GB, 6G and 12G (upto 8 data streams) type SDI streams. The maximum resolution it supports is 4096x2160p60 in 12G mode. The SDI Rx IP allows the configuration of the modes to be detected at run time or a fixed mode. It also allows the Framer to be enabled. A video lock event is generated when the incoming SDI mode and transport stream is detected and is stable for a configurable number of video clocks as programmed in the Video Lockout Window. When the input video stream is stopped or the type changed, a video unlock event is generated. The IP gives out the CRC and EDH error status. When the bridges are enabled, then the AXI-4 Stream of YUV 422 10 bit per component and 2 pixels per clock is sent out.
The SDI Rx Subsystem driver (xilinx-sdirxss.c) is based on the V4L2 framework.
It creates a subdev node(/dev/v4l-subdev*) which can be used to query and configure the UHD SDI Rx Subsystem IP.
The SDI Rx IP would be the first node in the video capture pipeline.
It exposes various V4L controls which can be used to configure the subsystem like auto detection of SDI modes, Framer enable, etc and query the status like CRC status, EDH errors, etc.
It also exposes certain V4L events like video unlock, bridge overflow/underflow, video source change, etc which can be used by application to trigger certain actions.
The general description of V4L2 framework is documented here, v4l2-framework.txt.
|IP feature||2018.1 on wards|
|Supports AXI4-Stream, native video and native SDI user interfaces||Supports only AXI4-Stream output interface|
|Support for 2 pixel per sample||Yes|
|10-bit per color component||Yes|
|Supports YUV 4:2:2 and YUV 4:2:0 color space||Yes|
|AXI4-Lite interface for register access to configure different subsystem options||Yes|
|Audio support||Separate driver|
Other driver features supported are -
- Detect SD, HD, 3GA/3GB, 6G, 12G (upto 8 Data Streams)
- Auto detect multiple modes OR Fixed Mode detection
- Framer enable/disable
- Programmable Video Lock Window
- EDH & CRC error counters
- Video Lock, Unlock, Bridge Over/UnderFlow interrupts
- Separate bits to control SDI to Native and Native to AXI4-S bridge
- ST352 Payload
- Mode and Transport type detection
- Fractional / Integral Frame rate
- Interlaced / Progressive Transport
- Family detection
Missing Features / Known Issues / Limitations in Driver
- In case of a HD stream without payload, a progressive segmented frame (pSF) will be reported incorrectly as Interlaced as the driver relies on the IP's transport scan locked bit.
- *Multiple instances capability not tested
- *Tested with only 12G 8DS configuration
- HD 1280x720p24 and HD 1280x720p23.98 - Incorrect colors are captured
- In some 3GB 1080 modes, the colors in color bars are swapped.
- Tested with Phabrix SDI generator and Omnitek Ultra4K
Kernel ConfigurationCONFIG_VIDEO_XILINX_SDIRXSS and CONFIG_VIDEO_XILINX should be enabled.
Device Tree BindingThe dts node should be defined with correct hardware configuration. How to define the node is documented in xlnx,sdirxss.txt
Certain parameters like Framer enable, Video lockout window, etc can be configured using the YAVTA tool as follows -
For example, to list all the controls and current values
Using VIDIOC_SUBDEV_G_FMT ioctl, the width, height and field type (interlaced or progressive) can be determined.
SDI Rx SS ==> VDMA S2MM OR Framebuffer Write ==> Memory
For example, to capture a 1920x1080 stream the following command is used The captured .bin files can then be viewed in yuvplayer.exe application.
Debug capabilityThe driver debug messages can be enabled by adding "#define DEBUG" at the top of the file.
All debug prints are sent to serial console and can be viewed in kernel dmesg buffer.
- The SDI source connected to SDI Rx port and should be running.
- The driver should have been loaded successfully during kernel bootup.
- Running media-ctl should show resolution.
E.g. “media-ctl –d /dev/media0 –p”
- Always check if the lock has occurred or not.
- If the lock is occurred, is the current mode (SD, HD, 3GA, 3GB, 6G, 12GI or 12GF) same as source?
- What is the ST352 payload in RX_ST352_DATA_DS1 register? Decode it to get resolution and size and color format.
- Refer to driver code how to decode.
- Compact GT Reset - There are 2 signals connected to compact_gt which need to be toggled to have a clean reset of the GT.
The SI5324_LOL should be toggled to high and then made low. (Default low)
The fmc_init_done line should be toggled to low and then high (Default high).
Q1 - While running yavta for resolution AxB with our source box, we see "Unable to start streaming: Invalid argument (22)." Why is this happening?
Ans - One possible reason is that the resolution that the SDI source is generating and what is being passed to yavta don't match.
Run media-ctl to find out the resolution currently being identified by the SDI Rx IP driver.
Read your SDI source documentation to know how to manipulate the resolutions.
Q2 - The frame rate reported by yavta is significantly lesser than expected.
Ans - Depending on your design and system load, there may be a case where there may be frame drops.
But double check the ST352 payload in SDI Rx to verify if the SDI source connected is correctly generating the required frame rate (fps).
You may have to refer to PG205 to decode the RX FAMILY to get the resolution and RX Frame Rate (in case of zero payload in 2017.3/4)
|rx_t_family||Transport Video Format||Active Pixels|
|0000||SMPTE ST 275||1920 x 1080|
|0001||SMPTE ST 296||1280 x 720|
|0010||SMPTE ST 2048-2||2048x1080|
|0011||SMPTE ST 295||1920 x 1080|
|1000||NTSC||720 x 486|
|1001||PAL||720 x 576|
Q3 - After boot up, even though there is valid SDI source connected, the IP is unable to detect the source and video is not locked. Why could this happen?
Ans - Check if the IP's registers are not default values after kernel boots up. E.g. MODULE_CTRL register should be 0x3F30. If the registers are in default state, it may mean the clocking to the IP is not correct. Please check device tree to set the correct clock source.
Boards SupportedDriver has been tested on the following boards
- ZCU106 1.0
- Fixed the media bus formats to 10 bpc type (MEDIA_BUS_FMT_UYVY10_1X20 and MEDIA_BUS_FMT_VYYUYY10_4X20).
- a2c1ff4 v4l: xilinx: sdirxss: Fix the media bus formats to 10bpc type
- Correct the SD 525i mode height to 486
- Add support for clock framework
- Correct the v4l2_field to V4L2_FIELD_ALTERNATE
- 11024d3 v4l: xilinx: sdirxss: Correct the v4l2_field to V4L2_FIELD_ALTERNATE
- Add support for YUV420 decoding
- Update Video lockout Window to 32 bit
- Added V4L controls for getting transport stream type, Active streams, 3G level B
- Added support to get frame rate
bd8f87c v4l: xilinx: sdirxss: Add V4L control for 3G Level B support
d9a3b95 v4l: xilinx: sdirxss: Add V4L control for Active streams
79d7896 v4l: xilinx: sdirxss: Add v4l control for transport stream type
3c2b606 v4l: xilinx: sdirxss: Add support for subdev get frame interval
4c3b2e3 v4l: xilinx: sdirxss: Add ST352 decode macros
031a2e1 v4l: xilinx: sdirxss: Decode ST352 in irq context
- Initial revision released.
726f7831 v4l: xilinx: sdirxss: Add source change event support
cba7215 v4l: xilinx: sdirxss: Decode HD mode stream in case of no payload
820df1b v4l: xilinx: sdirxss: Add support to decode 1080 line video in HD mode
f0e5fae v4l: xilinx: sdirxss: Add support to get width,height in SD mode
24ed4f9 v4l: xilinx: sdirxss: Add support to decode more ST352 payloads for 3G mode
4258d83 v4l: xilinx: sdirxss: Support decoding ST352 payload for 6G mode
3c5133a v4l: xilinx: sdirxss: Support decoding ST352 payload for 12G mode
b47af26 v4l: xilinx: sdirxss: Get EDH status only in case of SD mode
865daaa v4l: xilinx: sdirxss: Don't register EDH controls if EDH not enabled in IP core
c4258bf v4l: xilinx: sdirxss: Detect mode based on capability
edd5155 v4l: xilinx: sdirxss: Fix kbuild warning of variable used without initalizing
a5d7bad v4l: xilinx: sdirxss: Update for new register spec
89a7ff0 v4l: xilinx: sdirxss: Initial support for getting video stream properties
eb81908 v4l: xilinx: sdirxss: Add support for Video Unlock event
206948a v4l: xilinx: sdirxss: Add V4L get controls for Modes, CRC, EDH and Video Bridge Status
c9e6857 v4l: xilinx: sdirxss: Add V4L control for Mode detection
fcf25ff v4l: xilinx: sdirxss: Add V4L control for EDH error count
a5c2d98 v4l: xilinx: sdirxss: Add v4l control for Video Lock Window
4eaea74 v4l: xilinx: sdirxss: Add v4l control for Framer
6147fea v4l: xilinx: sdirxss: Streaming is enabled only on video lock
5c64f19 v4l: xilinx: sdirxss: Fix xsdirxss_core for kernel-doc
fcdd729 v4l: xilinx: Driver support for Xilinx UHDSDI Rx subsystem