tprins228
Posts: 1
Joined: Thu Jun 17, 2021 5:41 pm

imx219 register access

Thu Jun 17, 2021 5:45 pm

I need a way to directly access some of the registers for the IMX219. Specifically, I want to change 'windowing' of the sensor when using a selected resolution. On the OV5640 this was called "Image Windowing" (section 4.2 of the ov5640 spec). If I'm reading the IMX219 datasheet correctly, the imx219 calls this the Pixel Re-alignment in H and V directions and refer to the X_ADDR_STA_*, X_ADD_END_*, Y_ADD_STA_*, and Y_ADD_END_* registers. Any recommendations for how I can access these registers directly? I tried v4l2-dbg to read the registers but I get a "ioctl: VIDIOC_DBG_G_REGISTER failed" error. Any help would be greatly appreciated.

aBUGSworstnightmare
Posts: 3187
Joined: Tue Jun 30, 2015 1:35 pm

Re: imx219 register access

Fri Jun 18, 2021 5:05 am

Did you have a look at the libcamera sources on how to access the sensor?

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 11475
Joined: Wed Dec 04, 2013 11:27 am
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Re: imx219 register access

Fri Jun 18, 2021 3:57 pm

Driver at https://github.com/raspberrypi/linux/bl ... c/imx219.c for use with libcamera or if you want raw Bayer images.

Writing a driver that allows the creation of a generic crop is generally incredibly difficult due to dependencies between registers, hence the tabled list of modes. Allowing userspace to freely prod registers is also generally a bad idea, hence the S_REGISTER ioctl not being implemented (nor is CONFIG_VIDEO_ADV_DEBUG enabled in the kernel builds).
Feel free to mess with the register sets as you wish.
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