Unable to configure USB PHY

[AMurr.2282]

Hello ST community

I'm trying to configure the USB in OTG mode so I can upload linux to the NAND flash on my board (I'm using the STM32MP153AAC on a custom board).

Here's the output from the debug serial:

https://pastebin.com/f1UYcyDq

And here is dmesg on the host computer:

https://pastebin.com/Mj4fMGT2

From what I can tell, stm32prog is being executed by U-Boot on the board with the arguments "stm32prog usb 0". This causes the stm32-usbphyc device driver to be probed (successfully), and as can be seen in the dmesg output on the host computer, a new USB device is detected, but it doesn't seem to be communicating properly. The error is "device descriptor read/64, error -110"

I've followed all of the guides I could find on how to configure the DT:

https://wiki.st.com/stm32mpu/wiki/OTG_device_tree_configuration

https://wiki.st.com/stm32mpu/wiki/USBPHYC_device_tree_configuration

I've made sure the correct voltage regulators are selected, I've compared my configuration to both the STM32MP157C-EV1 and STM32MP157C-DK2 boards, and I'm at a loss as to what this means.

Here's my top-level device tree:

https://pastebin.com/Wb78tdX3

The relevant section can be found at the very bottom:

&usbh_ehci{
	status = "okay";
 
	/* USER CODE BEGIN usbh_ehci */
 phys = <&usbphyc_port0>;
 phy-names = "usb";
 vbus-supply = <&vbus_sw>;
	/* USER CODE END usbh_ehci */
};
 
&usbh_ohci{
	status = "okay";
 
	/* USER CODE BEGIN usbh_ohci */
 phys = <&usbphyc_port0>;
 phy-names = "usb";
 vbus-supply = <&vbus_sw>;
	/* USER CODE END usbh_ohci */
};
 
&usbotg_hs{
	pinctrl-names = "default"; /*, "sleep";*/
	pinctrl-0 = <&usb_otg_hs_pins_mx>;
	/*pinctrl-1 = <&usb_otg_hs_sleep_pins_mx>;*/
	status = "okay";
 
	/* USER CODE BEGIN usbotg_hs */
 /*dr_mode = "peripheral";*/
 phys = <&usbphyc_port1 0>;
 phy-names = "usb2-phy";
 vbus-supply = <&vbus_otg>;
	/* USER CODE END usbotg_hs */
};
 
&usbphyc{
	status = "okay";
 
	/* USER CODE BEGIN usbphyc */
 vdd3v3-supply = <&vdd>;
	/* USER CODE END usbphyc */
};
 
&usbphyc_port0{
	status = "okay";
 
	/* USER CODE BEGIN usbphyc_port0 */
 st,phy-tuning = <&usb_phy_tuning>;
	/* USER CODE END usbphyc_port0 */
};
 
&usbphyc_port1{
	status = "okay";
 
	/* USER CODE BEGIN usbphyc_port1 */
 st,phy-tuning = <&usb_phy_tuning>;
	/* USER CODE END usbphyc_port1 */
};