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AM3517: high-speed USB subsystem initialization for OHCI mode

Hi all,
I have to initialize port A (1) and port C (2) of high-speed USB subsystem of AM3517 in order to interface 2 external 6-pin serial transceivers (TI TUSB1105). Port 3 is not used. Operating system is Linux 2.6.31-rc7 (PSP 03.00.00.02). Since this working mode is not supported by PSP, I had to write a new device driver. As starting point I used the omap-echi driver. I'm facing the following problem when initializing TLL_CHANNEL_CONFIG_0 register.
Before writing this register (see this image http://www.dave.eu/download/tmp/sitara/usbtll-preinit.png), USBTLL_SYSSTATUS register reports "Reset is done" as expected (this is shown on window data.dump a:0x48062000 that refers to TLL registers memory region). As soon as TLL_CHANNEL_CONFIG_0 is written with value 0x184DB, TLL module enters reset state and never gets out of it (see http://www.dave.eu/download/tmp/sitara/usbtll-postinit.png).
So I suspect I'm missing something in channel initialization.
My configuration is pretty similar to the one described here:
http://e2e.ti.com/support/arm174_microprocessors/omap_applications_processors/f/42/t/28622.aspx
The major differences are:
1) I'm using port 1 and 2 in OHCI mode while Danny P sets up port 1 in EHCI, port 2 in OHCI and port 3 in OHCI
2) we are working with Linux while it seems Danny P used WinCE
3) we are working with AM3517 while Danny P worked with OMAP3515 but, as far as we know, the High-speed USB subsystem is the same.

Anybody experienced similar problems?

Thanks a lot in advance.

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