[nrf fromtree] usb: device_next: allow CDC ACM UART to be initialized and enabled at boot

There are some boards and samples in the tree that use the CDC ACM UART
as the default serial backend, just like a real UART controller would.
The new device stack requires more detailed configuration than the old
one. In order to use the CDC ACM UART as the serial backend with the new
device stack in the same way as with the legacy stack, we need to
provide a solution to initialise and enable the CDC ACM UART at boot
time. We cannot use snippets as they do not support Kconfig files or
source code. Shields would be an option, but they cannot be used for
virtual devices such as the CDC ACM UART. The remaining solution is to
put the code and Kconfig file for it in the subsys directory.

Allow CDC ACM UART instance and USB device stack to be initialized and
enabled at boot time and to use it as serial backend for logging or
shell.

Signed-off-by: Johann Fischer <[email protected]>
(cherry picked from commit 7ffa620)
Signed-off-by: Tomasz Moń <[email protected]>

Author: jfischer-no

subsys/usb/device_next/CMakeLists.txt

@@ -17,6 +17,8 @@ zephyr_library_sources(
 	usbd_msg.c
 )
 
+add_subdirectory(app)
+
 zephyr_library_sources_ifdef(
 	CONFIG_USBD_SHELL
 	usbd_shell.c

subsys/usb/device_next/Kconfig

@@ -56,5 +56,6 @@ config USBD_MSG_WORK_DELAY
 	  yet ready to publish the message. The delay unit is milliseconds.
 
 rsource "class/Kconfig"
+rsource "app/Kconfig.cdc_acm_serial"
 
 endif # USB_DEVICE_STACK_NEXT

subsys/usb/device_next/app/CMakeLists.txt

@@ -0,0 +1,4 @@
+# Copyright (c) 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_sources_ifdef(CONFIG_CDC_ACM_SERIAL_INITIALIZE_AT_BOOT cdc_acm_serial.c)

subsys/usb/device_next/app/Kconfig.cdc_acm_serial

@@ -0,0 +1,57 @@
+# Copyright (c) 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+# This file contains Kconfig options and defaults for configuring the USB
+# device stack and CDC ACM instance to be used as the default serial backend
+# for logging or shell.
+
+
+menuconfig CDC_ACM_SERIAL_INITIALIZE_AT_BOOT
+	bool "Initialize USB device and CDC ACM UART at boot"
+	depends on USBD_CDC_ACM_CLASS
+	help
+	  This is intended for use with cdc-acm-snippet or as a default serial
+	  backend only in applications where no other USB features are
+	  required, configured, and enabled.
+
+if CDC_ACM_SERIAL_INITIALIZE_AT_BOOT
+
+config CDC_ACM_SERIAL_MANUFACTURER_STRING
+	string "USB device manufacturer string descriptor"
+	default "Zephyr Project"
+	help
+	  USB device manufacturer string descriptor.
+
+config CDC_ACM_SERIAL_PRODUCT_STRING
+	string "USB device product string descriptor"
+	default "CDC ACM serial backend"
+	help
+	  USB device product string descriptor.
+
+config CDC_ACM_SERIAL_VID
+	hex "USB device Vendor ID"
+	default 0x2fe3
+	help
+	  You must use your own VID for samples and applications outside of
+	  Zephyr Project.
+
+config CDC_ACM_SERIAL_PID
+	hex "USB device Product ID"
+	default 0x0004
+	help
+	  You must use your own PID for samples and applications outside of
+	  Zephyr Project.
+
+config CDC_ACM_SERIAL_SELF_POWERED
+	bool "USB device Self-powered attribute"
+	help
+	  Set the Self-powered attribute in the configuration.
+
+config CDC_ACM_SERIAL_MAX_POWER
+	int "USB device bMaxPower value"
+	default 125
+	range 0 250
+	help
+	  bMaxPower value in the configuration in 2 mA units.
+
+endif #CDC_ACM_SERIAL_INITIALIZE_AT_BOOT

subsys/usb/device_next/app/cdc_acm_serial.c

@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdint.h>
+
+#include <zephyr/init.h>
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/usb/usbd.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(cdc_acm_serial, LOG_LEVEL_DBG);
+
+/*
+ * This is intended for use with cdc-acm-snippet or as a default serial backend
+ * only in applications where no other USB features are required, configured,
+ * and enabled. This code only registers the first CDC-ACM instance.
+ */
+
+USBD_DEVICE_DEFINE(cdc_acm_serial,
+		   DEVICE_DT_GET(DT_NODELABEL(zephyr_udc0)),
+		   CONFIG_CDC_ACM_SERIAL_VID, CONFIG_CDC_ACM_SERIAL_PID);
+
+USBD_DESC_LANG_DEFINE(cdc_acm_serial_lang);
+USBD_DESC_MANUFACTURER_DEFINE(cdc_acm_serial_mfr, CONFIG_CDC_ACM_SERIAL_MANUFACTURER_STRING);
+USBD_DESC_PRODUCT_DEFINE(cdc_acm_serial_product, CONFIG_CDC_ACM_SERIAL_PRODUCT_STRING);
+USBD_DESC_SERIAL_NUMBER_DEFINE(cdc_acm_serial_sn);
+
+USBD_DESC_CONFIG_DEFINE(fs_cfg_desc, "FS Configuration");
+USBD_DESC_CONFIG_DEFINE(hs_cfg_desc, "HS Configuration");
+
+static const uint8_t attributes = IS_ENABLED(CONFIG_CDC_ACM_SERIAL_SELF_POWERED) ?
+				  USB_SCD_SELF_POWERED : 0;
+
+USBD_CONFIGURATION_DEFINE(cdc_acm_serial_fs_config,
+			  attributes,
+			  CONFIG_CDC_ACM_SERIAL_MAX_POWER, &fs_cfg_desc);
+
+USBD_CONFIGURATION_DEFINE(cdc_acm_serial_hs_config,
+			  attributes,
+			  CONFIG_CDC_ACM_SERIAL_MAX_POWER, &hs_cfg_desc);
+
+
+static int register_cdc_acm_0(struct usbd_context *const uds_ctx,
+			      const enum usbd_speed speed)
+{
+	struct usbd_config_node *cfg_nd;
+	int err;
+
+	if (speed == USBD_SPEED_HS) {
+		cfg_nd = &cdc_acm_serial_hs_config;
+	} else {
+		cfg_nd = &cdc_acm_serial_fs_config;
+	}
+
+	err = usbd_add_configuration(uds_ctx, speed, cfg_nd);
+	if (err) {
+		LOG_ERR("Failed to add configuration");
+		return err;
+	}
+
+	err = usbd_register_class(&cdc_acm_serial, "cdc_acm_0", speed, 1);
+	if (err) {
+		LOG_ERR("Failed to register classes");
+		return err;
+	}
+
+	return usbd_device_set_code_triple(uds_ctx, speed,
+					   USB_BCC_MISCELLANEOUS, 0x02, 0x01);
+}
+
+
+static int cdc_acm_serial_init_device(void)
+{
+	int err;
+
+	err = usbd_add_descriptor(&cdc_acm_serial, &cdc_acm_serial_lang);
+	if (err) {
+		LOG_ERR("Failed to initialize language descriptor (%d)", err);
+		return err;
+	}
+
+	err = usbd_add_descriptor(&cdc_acm_serial, &cdc_acm_serial_mfr);
+	if (err) {
+		LOG_ERR("Failed to initialize manufacturer descriptor (%d)", err);
+		return err;
+	}
+
+	err = usbd_add_descriptor(&cdc_acm_serial, &cdc_acm_serial_product);
+	if (err) {
+		LOG_ERR("Failed to initialize product descriptor (%d)", err);
+		return err;
+	}
+
+	err = usbd_add_descriptor(&cdc_acm_serial, &cdc_acm_serial_sn);
+	if (err) {
+		LOG_ERR("Failed to initialize SN descriptor (%d)", err);
+		return err;
+	}
+
+	if (usbd_caps_speed(&cdc_acm_serial) == USBD_SPEED_HS) {
+		err = register_cdc_acm_0(&cdc_acm_serial, USBD_SPEED_HS);
+		if (err) {
+			return err;
+		}
+	}
+
+	err = register_cdc_acm_0(&cdc_acm_serial, USBD_SPEED_FS);
+	if (err) {
+		return err;
+	}
+
+	err = usbd_init(&cdc_acm_serial);
+	if (err) {
+		LOG_ERR("Failed to initialize device support");
+		return err;
+	}
+
+	err = usbd_enable(&cdc_acm_serial);
+	if (err) {
+		LOG_ERR("Failed to enable device support");
+		return err;
+	}
+
+	return 0;
+}
+
+SYS_INIT(cdc_acm_serial_init_device, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);

subsys/usb/device_next/class/Kconfig.cdc_acm

@@ -10,6 +10,7 @@ config USBD_CDC_ACM_CLASS
 	select SERIAL_SUPPORT_INTERRUPT
 	select RING_BUFFER
 	select UART_INTERRUPT_DRIVEN
+	default y
 	help
 	  USB device CDC ACM class implementation.