USB host and device functionality on SBC 6845 board using kernel modules

Question

I am working on SBC 6845(Atmel processor) in linux embedded development. My kernel version is 2.6.30.

This board comes with 2 USB ports(Both with Type A), one can be configured as host and other as USB device.

I have configured these USB modules in kernel. I have burned kernel and file system with necessary modules including USB modules. I have loaded these USB modules through /init.d/rcS file.

When board turns on and I type lsmod on console it shows me these modules loaded. When I connect board to computer, USB is not detected (device functionality).
When I connect pendrive to board, it is not detected (host functionality).

/init.d/rcS Script

#install USB Gadgate mass_storage
modprobe g_file_storage file=/home/mass_storage/backed_storage_file stall=n
losetup -o 4096 /dev/loop0 /home/mass_storage/backed_storage_file

#install USB ehci-hcd
modprobe ehci-hcd

rcS running log

g_file_storage gadget: File-backed Storage Gadget, version: 20 November 2008
g_file_storage gadget: Number of LUNs=1
g_file_storage gadget-lun0: ro=0, file: /home/mass_storage/backed_storage_file
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
atmel-ehci atmel-ehci: Atmel EHCI UHP HS
atmel-ehci atmel-ehci: new USB bus registered, assigned bus number 1
atmel-ehci atmel-ehci: irq 22, io mem 0x00800000
atmel-ehci atmel-ehci: USB 2.0 started, EHCI 1.00
usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
usb usb1: Product: Atmel EHCI UHP HS
usb usb1: Manufacturer: Linux 2.6.30 ehci_hcd
usb usb1: SerialNumber: atmel-ehci
usb usb1: configuration #1 chosen from 1 choice
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 2 ports detected

lsmod output

Module                  Size  Used by    Not tainted
ehci_hcd               30132  0
g_file_storage         24260  0

Any help is welcome!

Sylvain Huard Sylvain Huard · Accepted Answer · 2013-04-18T14:14:36

Your drivers seem well installed. I don't have a straight answer but I work with software-hardware integration very often. Here is what I would do to get more clues. That kind of processor often have pins that are multipurposes. Sometimes, on an evaluation board, they are not configured the way we want by default. You can look at the documentation but also, you can use an Oscilloscope and probe the D+ and D- of the USB. Are they OK when in IDLE? What happen when you connect a device on your host port? The first few things will be done by the USB controller and involves little even no interaction with the software after the controller is configured. If you see the beginning of a negociation (a bunch of 0s and 1s) then, you know your hardware is configured properly and your basic driver is installed and work properly. The result of this will narrow the scope of the problem.

USB host and device functionality on SBC 6845 board using kernel modules

2 Answers