Compute Module • Re: How to enable USB OTG on the CM5 IO board

The USB C connector and CC lines on CM5 are kind of misleading. My understanding is that the CC lines on CM5 are only for USB-C Power Delivery negotiations and are probably connected to the PMIC.

Correct the CC lines only go to the PMIC and the PMIC handles the USB-PD PHY but is under software control of the SoC

The USB 2.0 is a classic USB port and doesn't have CC controller and uses OTG_ID signal to recognize itself as host/device (with other criterias met, as required). I'm particularly intrigued by what architectural or functional changes might have been made to the USB 2.0 port in the CM5 relative to the CM4.

CM4 - used to have an XHCI and DWC2 controller wired into the same USB PHY
CM5 - No XHCI controller. I believe the DWC2 controller IP is almost identical to CM4 to reduce the risk of breaking rpiboot.

Statistics: Posted by timg236 — Thu Jun 12, 2025 12:46 pm

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