AM620-Q1: Adding CSI-2 Camera Support to SK-AM62-LP via J1 Connector

Hi Gopal,

If you have a DTB from a different device you can decompile it to dts and take it as a reference . you can reuse the camera configurations from the reference dts to k3-am62-lp-sk.dts. this is one Methode.

Ideal method is you can apply camera device tree overlay .

Eg:- Please refer to the OV5640 overlay: https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/arch/arm64/boot/dts/ti/k3-am62x-sk-csi2-tevi-ov5640.dtso?h=ti-linux-6.12.y.  you should be able to reuse this one and only change the I2C address and the "compatible" property according to your camera.

Note:- You can refer the below link to for creating a  camera device tree overlay and applying it.

https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/latest/exports/docs/linux/Foundational_Components/Kernel/Kernel_Drivers/Camera/CSI2RX.html

Hi Dilna K,

We integrated the OV2311 driver using the OV2312 reference driver as a base. The driver probes successfully, but we observed that memory allocation using devm_kzalloc fails, while allocation with kzalloc works as expected.

Is there a specific reason why devm_kzalloc might fail in this context? Also, is it mandatory to use devm_kzalloc, or is it acceptable to continue with kzalloc and handle cleanup manually?

Any guidance or recommended solutions would be appreciated.

Thanks,
Gopal Sharma

Hello Gopal,

gopal sharma said:

would like to add support for a CSI-2 camera via the J1 connector

Just to clarify. Can you share a picture of the SK-AM62-LP and circle the J1 connector? I just wanted to make sure I understand what you meant. I don't work with SK-AM62-LP that much.

gopal sharma said:

Is there a specific reason why devm_kzalloc might fail in this context? Also, is it mandatory to use devm_kzalloc, or is it acceptable to continue with kzalloc and handle cleanup manually?

Devm_kzalloc is the kzalloc in the platform device driver framework. While kzalloc succeeds, devm_kzalloc may still fail. The devm_kzalloc() requires a valid struct device pointer as its first argument. The allocation is tied to this device and will be automatically freed when the device is unbound or removed. If the parent device is not properly initialized or is in a state where resource allocation is restricted, devm_kzalloc() might fail. kzalloc(), on the other hand, is a standalone allocation and doesn't depend on a device context for its basic operation. 

So I would check if the first argument passed to devm_kzalloc() is valid: https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/drivers/media/i2c/ov2312.c?h=ti-linux-6.1.y#n604.

Regards,

Jianzhong

Hi Jianzhong,

Thank you for your support.

The devm_kzalloc issue has been resolved after some code cleanup. The device (camera module ov2311 ) is now detected at address 0x54 on the SK-AM62-LP (driver for this module is not present by default). On the Raspberry Pi, the same device is detected at 0x60 (driver already available for this module).

However, when reading the registers, we only get 0xFF.

Is there any specific I2C configuration required?
We have tested this using both the driver and i2cdump.

Please suggest any possible solution.

Image of Connector is:-


We are following the suggestions provided in the link below for the OV2311:
https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1535894/am620-q1-sample-device-tree-source-dts-for-ov2312-using-2-lane-mipi-csi-2-interface-on-sk-am62-lp?tisearch=e2e-sitesearch&keymatch=%25252520user%2525253A613007# 

Regards,
Gopal Sharma

gopal sharma said:

The devm_kzalloc issue has been resolved after some code cleanup. The device (camera module ov2311 ) is now detected at address 0x54 on the SK-AM62-LP (driver for this module is not present by default). On the Raspberry Pi, the same device is detected at 0x60 (driver already available for this module).

The same camera module should have the same I2C address. What does the data sheet of your camera see about the I2C address?

How did you connect the camera to the AM62 board? Would you mind sharing a picture?