usb: gadget: fsl_udc: pass controller instance to unregister ...

ci_udc_unregister() used to unregister "the controller". Since we
may register multiple chipidea devices we called ci_udc_unregister()
for each of them. This led to messages like:

ERROR: imx-usb 53f80000.usb: gadget not registered.

Fix this by returning the registered controller. This allows us to call
ci_udc_unregister() only when we actually registered one before.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

usb: chipidea: Add udc unregister for device removal ...

The host may assume that the usb device is still up and running after
booting if we do not deregister the udc here. I observed issues when the
linux kernel was using a usb gadget directly where the complete USB Hub
got disconnected through this.

This patch adds a proper USB disconnect for gadget devices.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

USB i.MX: Add chipidea gadget support ...

This adds USB gadget support to the i.MX chipidea driver. Basically
we have to add a register function to the fsl udc driver and call
this from the chipidea driver if device mode is selected.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add USB device support ...

This patch adds support for USB devices. It uses
the Linux Kernel gadget API. Along with this patch
comes driver support for the Freescale (arc) USB OTG
Core and USB Device Firmware Update (DFU)
The serial gadget support is not working at the moment.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>