Other NXP Products中的主题 Re: USB stack for iMX21?

USB stack for iMX21?

niksa — Sun, 08 Mar 2009 05:13:50 GMT

Hi all!

We are using iMX21 on our custom system, using our in-house developed RTOS. I need to add USB device functionality. Do there exist any USB stacks already ported on iMX21?

We have one open-source USB stack implementation, but it is not ported to iMX21, and before digging into this, I'd like to know if someone has already done that.

Thanks!

Re: USB stack for iMX21?

fabio_estevam — Mon, 09 Mar 2009 05:17:25 GMT

You can check this MX21 USB patch posted on ARM linux kernel mailing list: http://marc.info/?l=linux-arm-kernel&m=123654014123907&w=2

Regards,

Fabio Estevam

Re: USB stack for iMX21?

mfuzzey — Tue, 02 Jun 2009 00:04:08 GMT

Hi, I"m the one who posted the Linux MX21 USB Host Controller Driver mentionned above.

I should point out that is is _only_ the HCD component for _linux_. [Ie it is not a complete USB stack - linux already provides that fortunately, nor is it likely to be easilly portable to another (RT)OS.

I expect to post I new version soon which has most of the problems worked out and runs the usbtest suite sucessfully.

I've still got one strange problem : when multiple devices are using the bus it sometimes happens that the transfer completes (as witnessed by the completion code in the ETD being != 0xF (not accessed) and generally == 0x00 (Success)). However the ETD is not marked as done (and I don't get an interrupt). The problem never occurs with a single device using the bus.

I've worked around this in my driver by checking for this condition at each SOF but its not pretty.

Does anyone know anything about this? (can't find any mention of it in the errata).

Martin