usb: gadget: udc: amd5536: split core and PCI layer

This patch splits the amd5536udc driver into two -- one that does
pci device registration and the other file that does the rest of
the driver tasks like the gadget/ep ops etc for Synopsys UDC.

This way of splitting helps in exporting core driver symbols which
can be used by any other platform/pci driver that is written for
the same Synopsys USB device controller.

The current patch also includes a change in the Kconfig and Makefile.
A new config option USB_SNP_CORE will be selected automatically when
any one of the platform or pci driver for the same UDC is selected.

Main changes:
- amd5536udc_pci.c: PCI device registration is moved to this file.

- amd5536udc.c:
  This file does rest of the core UDC fucntionality.
  9 symbols are exported so as to be used by amd5536udc_pci.c.
  Module parameter definitions are moved to header file.

- amd5536udc.h:
  Function declarations, module parameters definitions and few common
  header file includes are added to this file

- Kconfig:
  New USB_SNP_CORE option is added which will be auto selected when
  any pci or platform driver config option for the UDC is chosen.

- Makefile:
  Compiles the core and pci files separately.

Signed-off-by: Raviteja Garimella <raviteja.garimella@broadcom.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/udc/Kconfig

@@ -254,6 +254,20 @@ config USB_MV_U3D
 	  MARVELL PXA2128 Processor series include a super speed USB3.0 device
 	  controller, which support super speed USB peripheral.
 
+config USB_SNP_CORE
+	depends on USB_AMD5536UDC
+	tristate
+	help
+	  This enables core driver support for Synopsys USB 2.0 Device
+	  controller.
+
+	  This will be enabled when PCI or Platform driver for this UDC is
+	  selected. Currently, this will be enabled by USB_SNP_UDC_PLAT or
+	  USB_AMD5536UDC options.
+
+	  This IP is different to the High Speed OTG IP that can be enabled
+	  by selecting USB_DWC2 or USB_DWC3 options.
+
 #
 # Controllers available in both integrated and discrete versions
 #
@@ -279,13 +293,17 @@ source "drivers/usb/gadget/udc/bdc/Kconfig"
 config USB_AMD5536UDC
 	tristate "AMD5536 UDC"
 	depends on PCI
+	select USB_SNP_CORE
 	help
 	   The AMD5536 UDC is part of the AMD Geode CS5536, an x86 southbridge.
 	   It is a USB Highspeed DMA capable USB device controller. Beside ep0
 	   it provides 4 IN and 4 OUT endpoints (bulk or interrupt type).
 	   The UDC port supports OTG operation, and may be used as a host port
 	   if it's not being used to implement peripheral or OTG roles.
 
+	   This UDC is based on Synopsys USB device controller IP and selects
+	   CONFIG_USB_SNP_CORE option to build the core driver.
+
 	   Say "y" to link the driver statically, or "m" to build a
 	   dynamically linked module called "amd5536udc" and force all
 	   gadget drivers to also be dynamically linked.

drivers/usb/gadget/udc/Makefile

@@ -10,7 +10,8 @@ obj-$(CONFIG_USB_GADGET)	+= udc-core.o
 obj-$(CONFIG_USB_DUMMY_HCD)	+= dummy_hcd.o
 obj-$(CONFIG_USB_NET2272)	+= net2272.o
 obj-$(CONFIG_USB_NET2280)	+= net2280.o
-obj-$(CONFIG_USB_AMD5536UDC)	+= amd5536udc.o
+obj-$(CONFIG_USB_SNP_CORE)	+= amd5536udc.o
+obj-$(CONFIG_USB_AMD5536UDC)	+= amd5536udc_pci.o
 obj-$(CONFIG_USB_PXA25X)	+= pxa25x_udc.o
 obj-$(CONFIG_USB_PXA27X)	+= pxa27x_udc.o
 obj-$(CONFIG_USB_GOKU)		+= goku_udc.o