Linux/PROCESSOR-SDK-AM437X: Camera controls in V4L2

Ken Li43

Tool/software: Linux

Hello,

I have successfully taken images from my fingerprint sensor. I need control the camera exposure and gain. I read that VPFE doesn't support VIDIOC_S_CTRL and VIDIOS_G_CTRL. How can I do the controls?

Thanks,

-Ken Li

over 7 years ago

0 Ken Li43 over 7 years ago

Intellectual 895 points

The following is from: processors.wiki.ti.com/.../Linux_Core_VPFE_User's_Guide

Supported ioctls
V4L2 ioctls Definition
VIDIOC_REQBUFS Allocating Memory Buffers
VIDIOC_QUERYBUF Getting Buffer's Physical Address
VIDIOC_QUERYCAP Query Capabilities
VIDIOC_ENUMINPUT Input Enumeration
VIDIOC_S_INPUT Set Input
VIDIOC_G_INPUT Get Input
VIDIOC_ENUMSTD Standard Enumeration
VIDIOC_QUERYSTD Query Standard
VIDIOC_S_STD Set Standard
VIDIOC_G_STD Get Standard
VIDIOC_ENUM_FMT Format Enumeration
VIDIOC_ENUM_FRAMESIZES Frame Size Enumeration
VIDIOC_S_FMT Set Format
VIDIOC_G_FMT Get Format
VIDIOC_TRY_FMT Try Format
VIDIOC_QUERYCTRL Query Control*
VIDIOC_S_CTRL Set Control*
VIDIOC_G_CTRL Get Control*
VIDIOC_QBUF Queue Buffer
VIDIOC_DQBUF Dequeue Buffer
VIDIOC_STREAMON Stream On
VIDIOC_STREAMOFF Stream Off
VIDIOC_CROPCAP Query Cropping Capabilities+
VIDIOC_S_CROP Set Crop Parameters+
VIDIOC_G_CROP Get Current Cropping Parameters+
*: API not implemented. The calls won't fails but will not have any effect.
+: API is implemented, but as not been tested.

0 Ken Li43 over 7 years ago in reply to Ken Li43

Intellectual 895 points

Do you have any updates? Thanks you.

-Ken L

0 Manisha Agrawal over 7 years ago in reply to Ken Li43

TI__Mastermind 22946 points

Hi Ken,

Unfortunately we do not support these ioctls at this moment. Source code of VPFE driver is available in our Processor SDK. You will need to enhance these IOCTLS for your need.

Regards,
Manisha

0 Ken Li43 over 7 years ago in reply to Manisha Agrawal

Intellectual 895 points

Thank you. Please give any hints how to modify the VPFE driver. Is it located in driver/media/v4l2-core ?

Thanks,

Ken

0 Manisha Agrawal over 7 years ago in reply to Ken Li43

TI__Mastermind 22946 points

Hi Ken,

Please look at drivers\media\platform\am437x\am437x-vpfe.c file. Look how existing ioctls are supported. You can find them in struct v4l2_ioctl_ops vpfe_ioctl_ops inside the am437x-vpfe.c file.

Regards,
Manisha

0 Ken Li43 over 7 years ago in reply to Manisha Agrawal

Intellectual 895 points

Thank you for your support. I have changed the file and added s_ctrl and g_ctrl for the ioctl. My functions in my sensor device driver can be called.

Thanks again.

-Ken

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Linux/PROCESSOR-SDK-AM437X: Camera controls in V4L2