USB armory USB driver - porting

[Vladimir Lushnikov]

Hello all,

It has taken a lot longer than I hoped initially, but I have some
progress to report on the USB driver port for the USB armory.

The current state is that the controller bringup looks like it *does
something*  but the functionality (and device hotplugging) does not work.

My current code is in here:
https://github.com/vladimir-lu/genode/tree/issue/imx53_usb_host_staging

As I mentioned, upon hotplugging a device (tested with a memory stick
and of course the official host adapter) - there seems to be no log
activity, but when the memory stick is plugged in from boot time it at
least recognises that there is something connected to the port. The two
log files are here:
https://gist.github.com/anonymous/101496bdfb266b460e51

The relevant line in the log is:
    [init -> usb_drv] dev_dbg: state 7 ports 1 chg 0002 evt 0000

vs (in the non-recognised case)
    [init -> usb_drv] dev_dbg: state 7 ports 1 chg 0000 evt 0000

I do not have any good ideas at the moment where to go next with
debugging this problem - can anyone suggest places to look?

I guessed that the issue is in the clock setup, but writing to the
Usboh3_60M and Usbphy1 in Ccgr2 and Ccgr4 respectively does not seem to
make any difference. The usb phy has no tranceiver on this platform so
does not need enabling. The OTG port is being used for host mode.

As you may notice, the platform.cc now contains a few header definitions
+ functions that I copy+pasted from the wifi driver but did not want to
put in lx_emul.cc - is that correct or should I just stick them in
linux_emul.cc for all to use?

I have also run the input-test and that does not print any events
received. One interesting line comes out after a few seconds however:

    [init -> usb_drv] dev_dbg: debounce: port 1: total 2000ms stable 0ms status 0x401

I want to get host mode working before I start with the OTG + gadget
porting (there is some diff primarily in the OTG stuff between 3.14.5
and 4.0 so I am not sure how much of 3.14.5 will actually "work" without
getting a 3.14.5 kernel running on the armory first...)

Kind regards,
Vladimir