How to Add a Custom Device Tree Overlay to Verdin AM62 Yocto Build?

Technical Support
6

Hi @raju3003!

First, did you add your layer to bblayers.conf? If not, it won’t consider your modifications when building the new image.

Second, your overlay isn’t correct. Please refer to this line of k3-am62-verdin.dtsi to use as an example on how you should write a node. In your overlay, you’ll need to add a node to &main_pmx0 and then change its function. Besides that, you must be sure that any other node doesn’t reserve the pin you’re trying to use and, if so, disable the node using the pin by adding status = "disabled" to it. Your overlay file would look like the following:

/dts-v1/;
/plugin/;

#include <dt-bindings/gpio/gpio.h>

/ {
        compatible = "toradex,verdin-am62";
};

&main_pmx0 {
        pinctrl_custom_pullup: main-custom-pullup {
                pinctrl-single,pins = <
                        AM62X_IOPAD(0x0094, PIN_INPUT_PULLUP, 7)
                >;
        };
};

The hexadecimal number is the pin physical address. You can find it in the AM62x Reference Manual. For example, you can find this pin used in the example on page 5832.

Besides that, the last argument in AM62X_IOPAD is the mux mode. You can find the possible modes in the Verdin AM62 Datasheet.

Best regards.
Lucas Azeituno