drivers: udc: add new UDC driver for SAM0 USB controller

The UDC driver for this beautiful USB controller is mostly rewritten
from scratch. USB Pad Calibration and clock handling are copied from the
usb_dc_sam0 driver.

The driver uses multipacket transfers for all endpoints except the OUT
control endpoint. The OUT control endpoint has a buffer that is always
mapped to the endpoint buffer register so that it always has a valid
buffer. The driver provides up to 7 IN and 7 OUT endpoints that support
any type of transfer. Double buffering is not used, for the possible
case of isochronous transfers some changes would be required in the
future.

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

Author: jfischer-no

drivers/usb/udc/CMakeLists.txt

@@ -21,3 +21,4 @@ zephyr_library_sources_ifdef(CONFIG_UDC_RPI_PICO udc_rpi_pico.c)
 zephyr_library_sources_ifdef(CONFIG_UDC_AMBIQ udc_ambiq.c)
 zephyr_library_sources_ifdef(CONFIG_UDC_RENESAS_RA udc_renesas_ra.c)
 zephyr_library_sources_ifdef(CONFIG_UDC_MAX32 udc_max32.c)
+zephyr_library_sources_ifdef(CONFIG_UDC_SAM0 udc_sam0.c)

drivers/usb/udc/Kconfig

@@ -78,5 +78,6 @@ source "drivers/usb/udc/Kconfig.rpi_pico"
 source "drivers/usb/udc/Kconfig.ambiq"
 source "drivers/usb/udc/Kconfig.renesas_ra"
 source "drivers/usb/udc/Kconfig.max32"
+source "drivers/usb/udc/Kconfig.sam0"
 
 endif # UDC_DRIVER

drivers/usb/udc/Kconfig.sam0

@@ -0,0 +1,28 @@
+# Copyright (c) 2025 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+config UDC_SAM0
+	bool "Driver for SAM0 family USB device controller"
+	default y
+	depends on DT_HAS_ATMEL_SAM0_USB_ENABLED
+	select PINCTRL
+	select SYS_MEM_BLOCKS
+	select EVENTS
+	help
+	  Driver for SAM0 family USB device controller.
+
+if UDC_SAM0
+
+config UDC_SAM0_STACK_SIZE
+	int "UDC controller driver internal thread stack size"
+	default 512
+	help
+	  Device controller driver internal thread stack size.
+
+config UDC_SAM0_THREAD_PRIORITY
+	int "UDC controller driver thread priority"
+	default 8
+	help
+	  Device controller driver thread priority.
+
+endif # UDC_SAM0