USB: EHCI: make ehci-orion a separate driver

Separate the Orion host controller driver from ehci-hcd host
code into its own driver module because of following reason.

With the multiplatform changes in arm-soc tree, it becomes
possible to enable the mvebu platform (which uses
ehci-orion) at the same time as other platforms that require
a conflicting EHCI bus glue. At the moment, this results
in a warning like

drivers/usb/host/ehci-hcd.c:1297:0: warning: "PLATFORM_DRIVER" redefined [enabled by default]
drivers/usb/host/ehci-hcd.c:1277:0: note: this is the location of the previous definition
drivers/usb/host/ehci-orion.c:334:31: warning: 'ehci_orion_driver' defined but not used [-Wunused-variable]

and an ehci driver that only works on one of them.

With the infrastructure added by Alan Stern in patch 3e0232039
"USB: EHCI: prepare to make ehci-hcd a library module", we can
avoid this problem by turning a bus glue into a separate
module, as we do here for the orion bus glue.

An earlier version of this patch was included in 3.9 but caused
a regression there, which has subsequently been fixed.

While we are here, use the opportunity to disabiguate the two
Marvell EHCI controller implementations in Kconfig.

In V4 (arnd):
- Improve Kconfig text

In V3:
- More detail provided in commit message regarding this patch.
- Replaced hcd_name string "ehci-orion" into "orion-ehci".
- MODULE_LICENSE is GPL v2.
- In ehci_init_driver calling second argument passed  as NULL instead of
  ehci_orion_overrides because ehci_orion_overrides is removed.

In V2:
- Tegra patch related changes removed from this patch.

Signed-off-by: Manjunath Goudar <manjunath.goudar@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index f7af098..c49a0b5 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -163,6 +163,17 @@
 	  Enables support for the on-chip EHCI controller on
 	  OMAP3 and later chips.
 
+config USB_EHCI_HCD_ORION
+	tristate  "Support for Marvell EBU on-chip EHCI USB controller"
+	depends on USB_EHCI_HCD && PLAT_ORION
+	default y
+	---help---
+	  Enables support for the on-chip EHCI controller on Marvell's
+	  embedded ARM SoCs, including Orion, Kirkwood, Dove, Armada XP,
+	  Armada 370.  This is different from the EHCI implementation
+	  on Marvell's mobile PXA and MMP SoC, see "EHCI support for
+	  Marvell PXA/MMP USB controller" for those.
+
 config USB_EHCI_MSM
 	bool "Support for MSM on-chip EHCI USB controller"
 	depends on USB_EHCI_HCD && ARCH_MSM
@@ -207,13 +218,17 @@
 	 Enable support for the S5P SOC's on-chip EHCI controller.
 
 config USB_EHCI_MV
-	bool "EHCI support for Marvell on-chip controller"
+	bool "EHCI support for Marvell PXA/MMP USB controller"
 	depends on USB_EHCI_HCD && (ARCH_PXA || ARCH_MMP)
 	select USB_EHCI_ROOT_HUB_TT
 	---help---
 	  Enables support for Marvell (including PXA and MMP series) on-chip
 	  USB SPH and OTG controller. SPH is a single port host, and it can
 	  only be EHCI host. OTG is controller that can switch to host mode.
+	  Note that this driver will not work on Marvell's other EHCI
+	  controller used by the EBU-type SoCs including Orion, Kirkwood,
+	  Dova, Armada 370 and Armada XP. See "Support for Marvell EBU
+	  on-chip EHCI USB controller" for those.
 
 config USB_W90X900_EHCI
 	bool "W90X900(W90P910) EHCI support"