drivers: udc: add USB device controller driver skeleton

Add a USB device controller driver skeleton to use as a starting point
for implementing a specific driver.

Signed-off-by: Johann Fischer <johann.fischer@nordicsemi.no>

drivers/usb/udc/CMakeLists.txt

@@ -6,4 +6,5 @@ zephyr_library()
 zephyr_library_sources(udc_common.c)
 zephyr_library_sources_ifdef(CONFIG_UDC_NRF udc_nrf.c)
 zephyr_library_sources_ifdef(CONFIG_UDC_KINETIS udc_kinetis.c)
+zephyr_library_sources_ifdef(CONFIG_UDC_SKELETON udc_skeleton.c)
 zephyr_library_sources_ifdef(CONFIG_UDC_VIRTUAL udc_virtual.c)

drivers/usb/udc/Kconfig

@@ -49,6 +49,7 @@ source "subsys/logging/Kconfig.template.log_config"
 
 source "drivers/usb/udc/Kconfig.nrf"
 source "drivers/usb/udc/Kconfig.kinetis"
+source "drivers/usb/udc/Kconfig.skeleton"
 source "drivers/usb/udc/Kconfig.virtual"
 
 endif # UDC_DRIVER

drivers/usb/udc/Kconfig.skeleton

@@ -0,0 +1,23 @@
+# Copyright (c) 2023 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+config UDC_SKELETON
+	bool "Skeleton for an USB device controller driver"
+	default y
+	depends on DT_HAS_ZEPHYR_UDC_SKELETON_ENABLED
+	help
+	  Skeleton for an USB device controller driver.
+
+config UDC_SKELETON_STACK_SIZE
+	int "UDC controller driver internal thread stack size"
+	depends on UDC_SKELETON
+	default 512
+	help
+	  Skeleton device controller driver internal thread stack size.
+
+config UDC_SKELETON_THREAD_PRIORITY
+	int "Skeleton controller driver thread priority"
+	depends on UDC_SKELETON
+	default 8
+	help
+	  Skeleton device controller driver thread priority.