usb: chipidea: improve kconfig 2.0

This patch provides a cleaner solution to the problem described in
commit 20a677fd ("usb: chipidea: improve kconfig").

The goal to be achieved is to force USB_CHIPIDEA=m if either
USB_EHCI_HCD=m or USB_GADGET=m.
If both are 'y' USB_CHIPIDEA may be selected to be 'm' or 'y'.

The old patch had the drawback, that USB_CHIPIDEA could be chosen as
'y' though USB_EHCI_HCD or USB_GADGET (or both) were 'm' leading to a
situation where USB_CHIPIDEA_HOST or USB_CHIPIDEA_UDC vanished from
the config options producing a compilable but dysfunctional driver.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Reviewed-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
usb: chipidea: ci_hdrc_imx: remove an unsolicited module_put() call from ci_hdrc_imx_remove()

This prevents the USB PHY refcount to be decremented below zero upon
unloading the ci-hdrc-imx module.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Acked-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
usb: chipidea: don't clobber return value of ci_role_start()

If a role fails to start, propagate the error code up the call stack
from probe.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
usb: chipidea: prevent endless loop registering platform_devices when probe fails

Commit 40dcd0e ("usb: chipidea: add PTW, PTS and STS handling") introduced
the following code to the ci_hdrc_probe() function:

+       if (!dev->of_node && dev->parent)
+               dev->of_node = dev->parent->of_node;

This inadvertently associates the ci_hdrc device with the ci_hdrc_imx
driver (which created the ci_hdrc device in the first place).

This results in ci_hdrc_imx_probe() being run for the ci_hdrc device
if ci_hdrc_probe() fails for some reason.
ci_hdrc_imx_probe() will happily create a new ci_hdrc platform_device
whose probing will likewise fail and trigger a new invocation of
ci_hdrc_imx_probe() ... ad nauseam.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Reviewed-and-Tested-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>