How do the application interface with ov5640 driver on imx8mp?

[Jayden_Soon]

I am developing with DART-MX8M-PLUS.

BSP : Yocto mx8mp-yocto-kirkstone-5.15-2.0.x-v1.2

I'm trying to interface with ov5640 driver (s_ctrl).

# Application Side

----------------------------------------------------------------------------------------------------------

int v4l2_Ctrl(int num, unsigned int id, int value)
{
struct v4l2_control control;
char dev_name[12];
int fd;

strcpy(dev_name, num==0 ? "/dev/video0" : "/dev/video1");

fd = open((const char *)dev_name, O_RDWR);
if(fd <= 0) {
printf("Cannot open %s device\n", dev_name);
return -1;
}

memset(&control, 0, sizeof (control));
control.id = id;
control.value = value;

if (ioctl(fd, VIDIOC_S_CTRL, &control) < 0)     ==> Error occurs at ioctl.
perror("VIDIOC_S_CTRL");

return 0;
}

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And Below is a list that is not in s_ctrl of "driver/media/i2c/ov5640.c"

How do I connect to the ov5460 driver in my application?

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root@imx8mp-var-dart:~# v4l2-ctl -d /dev/video1 -l

User Controls

horizontal_flip 0x00980914 (bool) : default=0 value=0
vertical_flip 0x00980915 (bool) : default=0 value=0
alpha_component 0x00980929 (int) : min=0 max=255 step=1 default=0 value=0

----------------------------------------------------------------------------------------------------------

Thanks.

Best regards,

Jayden

[araja]

Hi,

I have the same issue in my driver that subdev is not listing in /dev , My driver has the flag "sensor->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;"

Which module will mount the subdev under  /dev/v4l-subdev* ?

[Sanket_Parekh]

Hi @Jayden_Soon ,

I hope you are doing well.

Please make sure that you have used the correct control value for IOCTL.

Please make sure that you have used the correct device tree for the ov5640 camera

One can refer to the mx8_v4l2_cap_drm.c example at imx-test.

imx-test/test/mxc_v4l2_test/mx8_v4l2_cap_drm.c

Thanks & Regards,

Sanket Parekh

[Jayden_Soon]

Hi Sanket,

The dts file is orignal for DART-MX8M-PLUS.

When I run the code below as you say, an error occur.

---------------------------------------------------------------------------------------------------------------

memset(&ctrl, 0, sizeof(ctrl));
ctrl.id = V4L2_CID_AUTOGAIN;
ctrl.value = 1;
ret = ioctl(fd, VIDIOC_S_CTRL, &ctrl);

---------------------------------------------------------------------------------------------------------------

The interface doesn't seem to work with ov5640_s_ctrl.(drivers/media/i2c/ov5640.c)

---------------------------------------------------------------------------------------------------------------

static int ov5640_s_ctrl(struct v4l2_ctrl *ctrl)
{
struct v4l2_subdev *sd = ctrl_to_sd(ctrl);
struct ov5640_dev *sensor = to_ov5640_dev(sd);
int ret;

/* v4l2_ctrl_lock() locks our own mutex */

/*
* If the device is not powered up by the host driver do
* not apply any controls to H/W at this time. Instead
* the controls will be restored right after power-up.
*/
if (sensor->power_count == 0)
return 0;

switch (ctrl->id) {
case V4L2_CID_AUTOGAIN:
ret = ov5640_set_ctrl_gain(sensor, ctrl->val);
break;

---------------------------------------------------------------------------------------------------------------

Thanks,

Best regards,

Jayden

[Sanket_Parekh · Accepted solution]

Hi @Jayden_Soon 

I hope you are doing well.

Please share the logs of the error message that you got.

Please share if the is any v4l2 subdev node present under /dev,

ov5640.c driver uses V4L2_SUBDEV_FL_HAS_DEVNODE flag.So s_ctrl should be available using /dev/v4l-subdevX

Please refer to a below-mentioned thread where a similar issue is seen.

https://stackoverflow.com/questions/59055729/setting-ctrl-with-v4l2-on-ov5640

Please refer to V4L2 sub-devices for more details.

Thanks & Regards,

Sanket Parekh

[Jayden_Soon]

Hi Sanket,

I modified it as below and it works fine.

//sensor->sd.flags |= V4L2_SUBDEV_FL_HAS_EVENTS;
sensor->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;

Thank you so much for your reply.

Best regards,

Jadyen

[riteshkrmehta]

Hi @Jayden_Soon  ,

Is this solved the problem able to see all the controls in v4l2-ctl  --list-ctrls -d <devnode> ??

I did same change but not solving. Can you please let me know what else need to change in driver ?

Thanks in advance...

[Jayden_Soon]

Hi riteshkrmehta,

First, change it in your camera driver as below.

//sensor->sd.flags |= V4L2_SUBDEV_FL_HAS_EVENTS;
sensor->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;

Then, it is connected to "v4l-subdev#". The registered controls will appear in the list.

# v4l2-ctl -d /dev/v4l-subdev2 --list-ctrl

Thanks.

Best regards,

Jayden

[riteshkrmehta]

@Jayden_Soon ,

Thanks, Jayden its worked fine with me as well.

Actually, I was looking at the control for the final video node which is wrong, I need to look at subdev node which is actually the camera sensor node.

Thanks,

Ritesh Kumar

[Sanket_Parekh]

Hi @Jayden_Soon,

I hope you are doing well.

Glad to know that this resolves your issue,

Can i mark this case as close now?

Thanks & Regards,

Sanket Parekh