Initialisation of SOC USB pads

From: Igor Plyatov
Date: Mon May 13 2019 - 11:41:13 EST


Dear developers,

can you please explain who must configure AT91SAM9G20 SOC pads to operate as USB Host port? Is it AT91Bootstrap, U-Boot bootloader, Linux kernel or this is not required at all?

I ask, because during connection of USB disk, my board complains

usb 1-1: device descriptor read/64, error -62
usb 1-1: device descriptor read/64, error -62
usb 1-1: device descriptor read/64, error -62
usb 1-1: device descriptor read/64, error -62
usb 1-1: device not accepting address 4, error -62
usb 1-1: device not accepting address 5, error -62
usb usb1-port1: unable to enumerate USB device


Looks like there is no connectivity between USB Host module of SOC and USB device. Or am I wrong?


My setup is:


* AT91SAM9G20 based custom board;
* Linux kernel 4.9.36, from LINUX4SAM project.
* USB disk connected to USB Host port 0 (HDPA, HDMA pins of SOC). 39 Ohm series resistors and 15 Kohm pull-down resistors added at these lines. Connectivity between SOC and USB device confirmed by Ohmmeter.
* USB_VBUS voltage measured at USB connector = 4.96 VDC.

Best wishes
--
Igor Plyatov