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