Linux/AM4378: Tri-stating GPIO pins

Aaron Gao

Part Number: AM4378

Tool/software: Linux

Chip: AM4378

How should I set GPIO to high-impedence or tri-state on am4378?

When I check am335x processor document: SPRS717J PIN Attributes chapter, it shows that IO is High-impedence as default as below. Also in am335x TRM Chapter9.3.1.50 conf_<module>_<pin>， it can enable/disable pin pullup/pulldown. But I cannot find this in am4378 TRM, also am4378 document SPRS851D shows Pullup/Pulldown as default after reset instead of high-impedence.

Then, I check Linux/Documentation/devicetree/bindings/pinctl/ti,iodelay-pinctl.txt, it has below example:

pinctl-single, pins = <

0x9c (PIN_INPUT_PULLUP | MANUAL_MODE | MUX_MODE1)

Then, I also cannot find about high-impedence or tri-state attributes settings in <TI PINMUX Tool>.

So can someone help me? thanks a lot. Looking forward for your reply.