Weeks ago we talked about porting NuttX to PinePhone, and how we might turn it into a Feature Phone.
But to make phone calls and send text messages, we need to control the LTE Modem over USB. Thus today we’ll build a USB Driver for NuttX on PinePhone… 1. What’s USB Enhanced Host Controller Interface (EHCI) 2. Why it’s simpler than USB On-The-Go (OTG) 3. How we ported the USB EHCI Driver from NuttX to PinePhone 4. Handling USB Clocks and USB Resets on PinePhone (with tips from U-Boot Bootloader) 5. And the NuttX EHCI Driver boots OK on PinePhone! 🎉 https://lupyuen.github.io/articles/usb3 Lup
