usb: host: class: add a placeholder call after a device is connected

Add an ad-hoc placeholder that allows executing custom code as soon as
a device is connected on the bus, so that enumeration can continue
with the class-specific parts in the meantime that a complete.
The assumption is that this would be replaced in future development.

Signed-off-by: Josuah Demangeon <[email protected]>

Author: Josuah Demangeon

subsys/usb/host/usbh_class.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_INCLUDE_USBH_CLASS_H
+#define ZEPHYR_INCLUDE_USBH_CLASS_H
+
+#include <stdint.h>
+#include <zephyr/usb/usbh.h>
+#include <zephyr/drivers/usb/uhc.h>
+
+int usbh_class_init(struct usb_device *udev);
+
+#endif /* ZEPHYR_INCLUDE_USBH_CLASS_H */

subsys/usb/host/usbh_core.c

@@ -13,6 +13,7 @@
 
 #include "usbh_internal.h"
 #include "usbh_device.h"
+#include "usbh_class.h"
 
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(uhs, CONFIG_USBH_LOG_LEVEL);
@@ -70,6 +71,11 @@ static void dev_connected_handler(struct usbh_contex *const ctx,
 
 	if (usbh_device_init(ctx->root)) {
 		LOG_ERR("Failed to reset new USB device");
+		return;
+	}
+
+	if (usbh_class_init(ctx->root)) {
+		LOG_ERR("Failed to initialize device class");
 	}
 }