STM32MP257F-DK OTG failed to connect iPhone 14

[dothanhtrung]

Hi.

I am trying to connect iPhone 14 (lightning port) to OTG (CN15) on STM32MP257F-DK, but there is no connection.

• iPhone 14 is not charged. No USB connection is shown on iPhone.
• On the board:
  • `lsusb` does not show any new connection.
  • `dmesg` does not show any new log, like there is no new cable plugged at all.

The lightning-to-C cable has been tested with other devices and works fine.

iPhone 16 (type-C port) can connect to OTG to be charged and do USB tethering just fine.

I am already using the newest kernel 6.6.78 from https://github.com/STMicroelectronics/linux, branch "v6.6-stm32mp".

So I would like to confirm if OTG on STM32MP257F-DK support lightning connection or not.

Thank you.

[Billy OWEN]

Hi @dothanhtrung 

This post has been escalated to the ST Online Support Team for additional assistance.  We'll contact you directly.

Regards,

Billy

[Bossen · Accepted solution]

Hi dothanhtrung,

Let me add the information here for others who encountered same issue.

The root cause is the firmware of Cortex-M33 is stopped manually. By default, CM33 FW is loaded automatically thanks to the system services. The CM33 FW manages CC communication of type-C port, as well as the cable detection of USB type-C. When the firmware is stopped, there is no notification to system when USB is attached. No USB is recognized then.

Best Regards,

Bossen WU