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How to power-up/down camera with V4L2?

Hi!
I'm trying to find a way to power-up an OV5645 image sensor in my system (Dragonboard 410c running Linaro Linux R.19.01). In its driver (ov5645.c) there are code like:

static int ov5645_s_power(struct v4l2_subdev *sd, int on)
{
:
}
:
static const struct v4l2_subdev_core_ops ov5645_core_ops = {
.s_power = ov5645_s_power,
};

Calling ov5645_s_power() will power-up or power-down this OV5645. And I found that the program gst-launch-1.0 may call ov5645_s_power() internally, but I just don't know how it can do this. I'm wondering whether there is anyway I can use any V4L2 control (maybe something like V4L2_CID_***?) to get ov5645_s_power() to be called, so I can arbitrarily power this OV5645 up/down?

I'm not sure whether this question is a proper one for this forum or not. If not, could anyone advice a better place where I can post this question?

What do you get with

Code:

v4l2-ctl --all?

Hi Zeebra,
First thank you for your reply.
By

Code:

v4l2-ctl --all

I get:

Code:

linaro@linaro-developer:~$ v4l2-ctl --all

Driver Info:

        Driver name      : qcom-camss

        Card type        : Qualcomm Camera Subsystem

        Bus info        : platform:1b0ac00.camss

        Driver version  : 4.14.96

        Capabilities    : 0x85201000

                Video Capture Multiplanar

                Read/Write

                Streaming

                Extended Pix Format

                Device Capabilities

        Device Caps      : 0x05201000

                Video Capture Multiplanar

                Read/Write

                Streaming

                Extended Pix Format

Media Driver Info:

        Driver name      : qcom-camss

        Model            : Qualcomm Camera Subsystem

        Serial          : 

        Bus info        : 

        Media version    : 4.14.96

        Hardware revision: 0x00000000 (0)

        Driver version  : 4.14.96

Interface Info:

        ID              : 0x03000018

        Type            : V4L Video

Entity Info:

        ID              : 0x00000016 (22)

        Name            : msm_vfe0_video0

        Function        : V4L2 I/O

        Pad 0x01000017  : Sink

          Link 0x0200001a: from remote pad 0x1000015 of entity 'msm_vfe0_rdi0': Data, Enabled, Immutable

Priority: 2

Video input : 0 (camera: ok)

Format Video Capture Multiplanar:

        Width/Height      : 1920/1080

        Pixel Format      : 'UYVY' (UYVY 4:2:2)

        Field            : None

        Number of planes  : 1

        Flags            : 

        Colorspace        : sRGB

        Transfer Function : sRGB

        YCbCr/HSV Encoding: ITU-R 601

        Quantization      : Full Range

        Plane 0          :

          Bytes per Line : 3840

          Size Image    : 4147200

Any comment?

Finally I've found how to power-up this camera module:
1. Configure the Media Controller pipeline like:

sudo media-ctl -d /dev/media0 -l '"msm_csiphy0":1->"msm_csid0":0[1],"msm_csid0":1->"msm_ispif0":0[1],"msm_ispif0":1->"msm_vfe0_rdi0":0[1]'

2. Open its corresponding /dev/video*

Then ov5645_s_power() will be call to power this OV5645 up.

FYR.