TDA4VEN-Q1: How to enable the gpio subsystem

Hi,

You can search "CONFIG_GPIO_DAVINCI=y" within the menuconfig. You can find more information here.

Ensure to save the config and compile the kernel using your custom configuration. You can find more information here.

Thanks,

Neehar

Hi Neehar,

This doesn't seem to be effective. I still can't find the gpio directory under /sys/class.

Regards.

Hi,

Let me look into this further and get back to you.

Thanks,

Neehar

Hi Neehar,

I'm sorry to disturb you during your vacation.

Referring to the code of tool/gpio in the kernel, I chose the solution of replacing the sysfs interface with the chardev interface to implement operations on gpio.

There is another non urgent question, I hope you can take some time to help me take a look after you return from vacation.

I'm not sure how to define GPOS 512-535 and how index 512-535 correspond to the offset of gpio?

Regards.

Hi,

xie jc said:

Referring to the code of tool/gpio in the kernel, I chose the solution of replacing the sysfs interface with the chardev interface to implement operations on gpio.

Yes, if you look at this documentation, sysfs has been deprecated since Linux 4.8 and user space should use the character device instead.

xie jc said:

I'm not sure how to define GPOS 512-535 and how index 512-535 correspond to the offset of gpio?

What do you mean by define? Based on the GPIO addresses within the screenshot, you can tell which GPIO instance it is.

Thanks,

Neehar

Hi Neehar,

What I am puzzled about is that the index of gpio starts from 512 instead of 0?

Regards.