Backend driver for MUSB OTG controllers found on TI AM35x.
It seems that on AM35X interrupt status registers can be updated
_before_ core registers. As we don't use true interrupts in U-Boot
and poll interrupt status registers instead this can result in
interrupt handler being called with non-updated core registers.
This confuses the code and result in hanged transfers.
Add a small delay in am35x_interrupt as a workaround.
Signed-off-by: Ilya Yanok <ilya.yanok@cogentembedded.com>
Existing U-Boot musb driver has no support for the new gadget framework
and also seems to have other limitations. As gadget framework is ported
from Linux it seems pretty natural to port musb gadget driver as well.
This driver supports both host and peripheral modes.
This is not a replacement for current musb driver (at least now) as
there are still some consumers of the old UDC interface.
No DMA operation support included, CONFIG_MUSB_PIO_ONLY should be
defined.
Virtual root hub device is not implemented.
Known problems: with no devices connected usb_lowlevel_start() fails.
Signed-off-by: Ilya Yanok <ilya.yanok@cogentembedded.com>
Ilya Yanok