89013969e2
Use the multistream series function video_device_pipeline_alloc_start to allows multiple clients of the same pipeline. If the VFE entity is used by another instance of the pipeline, the pipeline won't be stopped. This allows for stopping and starting streams at any point without disrupting the other running streams. To prepare and start multiple virtual channels each CSID source pad corresponding to a virtual channel must be linked to the corresponding IFE entity. CSID pad 1 (1st source pad) corresponds to virtual channel 0, CSID pad 2 corresponds to virtual channel 1 and so on. Each of these must be linked to corresponding IFE RDI port. E.g. to enable vc 0 on CSID0: media-ctl -l '"msm_csid0":1->"msm_vfe0_rdi0":0[1]' To enable vc1 on CSID0: media-ctl -l '"msm_csid0":2->"msm_vfe0_rdi1":0[1]' And so on. Note that on SM8250 each CSID is connected, at the hardware level, to only one IFE. Thus, you must link CSID0 with IFE0, you can't link it with IFE1. Example: the following media controller setup expects multiplexed sensor data on CSIPHY2. Data will be passed on to CSID0, which will demux it to 2 streams - for RDI0 and RD1 ports of IFE0: media-ctl -v -d /dev/media0 -V '"imx577 '22-001a'":0[fmt:SRGGB10/3840x2160 field:none]' media-ctl -V '"msm_csiphy2":0[fmt:SRGGB10/3840x2160]' media-ctl -V '"msm_csid0":0[fmt:SRGGB10/3840x2160]' media-ctl -V '"msm_csid0":1[fmt:SRGGB10/3840x2160]' media-ctl -V '"msm_csid0":2[fmt:SRGGB10/3840x2160]' media-ctl -V '"msm_vfe0_rdi0":0[fmt:SRGGB10/3840x2160]' media-ctl -V '"msm_vfe0_rdi1":0[fmt:SRGGB10/3840x2160]' media-ctl -l '"msm_csiphy2":1->"msm_csid0":0[1]' media-ctl -l '"msm_csid0":1->"msm_vfe0_rdi0":0[1]' media-ctl -l '"msm_csid0":2->"msm_vfe0_rdi1":0[1]' Note: CSID's entity pad 0 is a sink pad, pads 1..4 are source pads To start streaming a v4l2 client must open the corresponding /dev/videoN node. For example, with yavta: yavta -B capture-mplane -c -I -n 5 -f SRGGB10P -s 3840x2160 -F /dev/video0 yavta -B capture-mplane -c -I -n 5 -f SRGGB10P -s 3840x2160 -F /dev/video1 Note that IFEs (vfe0, vfe1) on SM8250 have 3 RDI ports and a single PIX port and IFELites (vfe2, vfe3) have 4 RDI ports and no PIX port. Signed-off-by: Milen Mitkov <quic_mmitkov@quicinc.com> Reviewed-by: Robert Foss <robert.foss@linaro.org> Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> Acked-by: Robert Foss <robert.foss@linaro.org> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.