PROCESSOR-SDK-AM62X: is there any example for GMSL camera

Hello Leijie,

Sorry, but we don't have any example of using GMSL cameras with AM62x.

Regards,

Jianzhong

can you suggest how to make video device /dev/video0 ready using GMSL or FPD link camera?

actually what I want is a dummy driver, which make video device ready, and the initialization can be from userspace. then v4l2 is able to capture the stream.

Let me check internally and see if I can find any guidance on this. Please expect some delay in response.

Please refer to the FPLink drivers in TI's Linux kernel:

• DS90UB953 serializer: https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/drivers/media/i2c/ds90ub953.c?h=ti-linux-5.10.y
• DS90UB960 deserializer: https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/drivers/media/i2c/ds90ub960.c?h=ti-linux-5.10.y

Also, the CSI2 RX driver: https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c?h=ti-linux-5.10.y

thanks, I will check how to write a dummy sensor driver.  

have you ever checked if internal has already a solution on it?

No, we don't have support for GMSL in our drivers, even internally.

actually I'm not talking about the GMSL driver, I'm talking about dummy sensor driver, which help to link to V4L2 subsystem even no sensor attached.

Hi Jianzhong,

Where does the data flow through csi2rx go, can you point out this part of the code?

Hi Leijie,

Could you please elaborate more on your question?

Thanks,

Jianzhong

Hi Jianzhong,

the data flow is generally sensor->mipi->isp, I think am625 has no isp, so I wonder is csi2rx put the data directly to ram through dma? 

so all related components in SOC should be cdns-dphy.c cdns-csi2rx.c and j721e-csi2rx.c, any others? please corrct me if it's not right.

Hi Jianzhong,

with the dummy sensor driver, now I see below result, can you comment if it's as expect.

why there's 4 video node?

root@am62xx-z067-dms:/sys/class/gpio# v4l2-ctl --list-devices
j721e-csi2rx (platform:30102000.ticsi2rx):
        /dev/video0
        /dev/video1
        /dev/video2
        /dev/video3
        /dev/media0

root@am62xx-z067-dms:/sys/class/gpio# media-ctl -d /dev/media0 -p
Media controller API version 5.10.109

Media device information
------------------------
driver          j721e-csi2rx
model           TI-CSI2RX
serial
bus info        platform:30102000.ticsi2rx
hw revision     0x1
driver version  5.10.109

Device topology
- entity 1: 30102000.ticsi2rx (5 pads, 5 links)
            type V4L2 subdev subtype Unknown flags 0
            device node name /dev/v4l-subdev0
        pad0: Sink
                <- "cdns_csi2rx.30101000.csi-bridge":1 [ENABLED,IMMUTABLE]
        pad1: Source
                -> "30102000.ticsi2rx context 0":0 [ENABLED,IMMUTABLE]
        pad2: Source
                -> "30102000.ticsi2rx context 1":0 [ENABLED,IMMUTABLE]
        pad3: Source
                -> "30102000.ticsi2rx context 2":0 [ENABLED,IMMUTABLE]
        pad4: Source
                -> "30102000.ticsi2rx context 3":0 [ENABLED,IMMUTABLE]

- entity 7: cdns_csi2rx.30101000.csi-bridge (5 pads, 2 links)
            type V4L2 subdev subtype Unknown flags 0
            device node name /dev/v4l-subdev1
        pad0: Sink
                <- "dummy_csi2_sensor":0 [ENABLED,IMMUTABLE]
        pad1: Source
                -> "30102000.ticsi2rx":0 [ENABLED,IMMUTABLE]
        pad2: Source
        pad3: Source
        pad4: Source

- entity 13: dummy_csi2_sensor (1 pad, 1 link)
             type V4L2 subdev subtype Sensor flags 0
             device node name /dev/v4l-subdev2
        pad0: Source
                [fmt:UYVY8_2X8/640x480 field:none colorspace:srgb xfer:srgb ycbcr:601 quantization:full-range]
                -> "cdns_csi2rx.30101000.csi-bridge":0 [ENABLED,IMMUTABLE]

- entity 19: 30102000.ticsi2rx context 0 (1 pad, 1 link)
             type Node subtype V4L flags 0
             device node name /dev/video0
        pad0: Sink
                <- "30102000.ticsi2rx":1 [ENABLED,IMMUTABLE]

- entity 25: 30102000.ticsi2rx context 1 (1 pad, 1 link)
             type Node subtype V4L flags 0
             device node name /dev/video1
        pad0: Sink
                <- "30102000.ticsi2rx":2 [ENABLED,IMMUTABLE]

- entity 31: 30102000.ticsi2rx context 2 (1 pad, 1 link)
             type Node subtype V4L flags 0
             device node name /dev/video2
        pad0: Sink
                <- "30102000.ticsi2rx":3 [ENABLED,IMMUTABLE]

- entity 37: 30102000.ticsi2rx context 3 (1 pad, 1 link)
             type Node subtype V4L flags 0
             device node name /dev/video3
        pad0: Sink
                <- "30102000.ticsi2rx":4 [ENABLED,IMMUTABLE]

root@am62xx-z067-dms:/sys/class/gpio#

Hello Leijie,

Yes, that's expected. TI's CSI2-RX driver wrapper (j721e-csi2rx.c) creates these video devices. They are not only for camera sensors, but also for other things using DMA. In addition, creating multiple video devices can support multiple sensors (that would require a CSI aggregator). 

Regards,

Jianzhong