usb: gadget: add Aspeed ast2600 udc driver

Aspeed udc is compliant with USB2.0, supports USB High Speed
and Full Speed, backward compatible with USB1.1.

Supports independent DMA channel for each generic endpoint.
Supports 32/256 stages descriptor mode for all generic endpoints.

This driver supports full functionality including single/multiple
stages descriptor mode, and exposes 1 UDC gadget driver.
Signed-off-by: Neal Liu <neal_liu@aspeedtech.com>
Link: https://lore.kernel.org/r/20220523030134.2977116-2-neal_liu@aspeedtech.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS

@@ -3136,6 +3136,13 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/media/aspeed-video.txt
 F:	drivers/media/platform/aspeed/
 
+ASPEED USB UDC DRIVER
+M:	Neal Liu <neal_liu@aspeedtech.com>
+L:	linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)
+S:	Maintained
+F:	Documentation/devicetree/bindings/usb/aspeed,udc.yaml
+F:	drivers/usb/gadget/udc/aspeed_udc.c
+
 ASUS NOTEBOOKS AND EEEPC ACPI/WMI EXTRAS DRIVERS
 M:	Corentin Chary <corentin.chary@gmail.com>
 L:	acpi4asus-user@lists.sourceforge.net

drivers/usb/gadget/udc/Kconfig

@@ -463,6 +463,19 @@ config USB_TEGRA_XUDC
 	 dynamically linked module called "tegra_xudc" and force all
 	 gadget drivers to also be dynamically linked.
 
+config USB_ASPEED_UDC
+	tristate "Aspeed UDC driver support"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	depends on USB_LIBCOMPOSITE
+	help
+	  Enables Aspeed USB2.0 Device Controller driver for AST260x
+	  family SoCs. The controller supports 1 control endpoint and
+	  4 programmable endpoints.
+
+	  Say "y" to link the driver statically, or "m" to build a
+	  dynamically linked module called "aspeed_udc" and force all
+	  gadget drivers to also be dynamically linked.
+
 source "drivers/usb/gadget/udc/aspeed-vhub/Kconfig"
 
 #

drivers/usb/gadget/udc/Makefile

@@ -40,5 +40,6 @@ obj-$(CONFIG_USB_GR_UDC)	+= gr_udc.o
 obj-$(CONFIG_USB_GADGET_XILINX)	+= udc-xilinx.o
 obj-$(CONFIG_USB_SNP_UDC_PLAT) += snps_udc_plat.o
 obj-$(CONFIG_USB_ASPEED_VHUB)	+= aspeed-vhub/
+obj-$(CONFIG_USB_ASPEED_UDC)	+= aspeed_udc.o
 obj-$(CONFIG_USB_BDC_UDC)	+= bdc/
 obj-$(CONFIG_USB_MAX3420_UDC)	+= max3420_udc.o