usb: device_next: add experimental CDC ACM implementation

Add experimental CDC ACM implementation for new USB device stack.
It currently implements only UART IRQ API support and is WIP.

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

subsys/usb/device_next/CMakeLists.txt

@@ -26,4 +26,9 @@ zephyr_library_sources_ifdef(
 	class/loopback.c
 )
 
+zephyr_library_sources_ifdef(
+	CONFIG_USBD_CDC_ACM_CLASS
+	class/usbd_cdc_acm.c
+)
+
 zephyr_linker_sources(DATA_SECTIONS usbd_data.ld)

subsys/usb/device_next/class/Kconfig

@@ -3,3 +3,4 @@
 # SPDX-License-Identifier: Apache-2.0
 
 rsource "Kconfig.loopback"
+rsource "Kconfig.cdc_acm"

subsys/usb/device_next/class/Kconfig.cdc_acm

@@ -0,0 +1,29 @@
+# Copyright (c) 2022 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: Apache-2.0
+
+config USBD_CDC_ACM_CLASS
+	bool "USB CDC ACM implementation [EXPERIMENTAL]"
+	depends on SERIAL
+	depends on DT_HAS_ZEPHYR_CDC_ACM_UART_ENABLED
+	select SERIAL_HAS_DRIVER
+	select SERIAL_SUPPORT_INTERRUPT
+	select RING_BUFFER
+	select UART_INTERRUPT_DRIVEN
+	help
+	  USB device CDC ACM class implementation.
+
+if USBD_CDC_ACM_CLASS
+
+config USBD_CDC_ACM_STACK_SIZE
+	int "USB CDC ACM workqueue stack size"
+	default 1024
+	help
+	  USB CDC ACM workqueue stack size.
+
+module = USBD_CDC_ACM
+module-str = usbd cdc_acm
+default-count = 1
+source "subsys/logging/Kconfig.template.log_config"
+
+endif