usb: device_next: support BOS descriptor with vendor request code

Platform capability descriptors such as MSOSv2 or WebUSB BOS have a
vendor request code that is used by the host to perform vendor-specific
requests. Add a convenient way to define and register a platform
capability descriptor with a vendor request node.

Signed-off-by: Johann Fischer <[email protected]>

Author: jfischer-no

include/zephyr/usb/usbd.h

@@ -74,6 +74,7 @@ enum usbd_str_desc_utype {
 
 enum usbd_bos_desc_utype {
 	USBD_DUT_BOS_NONE,
+	USBD_DUT_BOS_VREQ,
 };
 /** @endcond */
 
@@ -145,6 +146,9 @@ struct usbd_vreq_node {
 struct usbd_bos_desc_data {
 	/** Descriptor usage type (not bDescriptorType) */
 	enum usbd_bos_desc_utype utype : 8;
+	union {
+		struct usbd_vreq_node *const vreq_nd;
+	};
 };
 
 /**
@@ -662,6 +666,34 @@ static inline void *usbd_class_get_private(const struct usbd_class_data *const c
 		.to_dev = vto_dev,						\
 	}
 
+/**
+ * @brief Define BOS Device Capability descriptor node with vendor request
+ *
+ * This macro defines a BOS descriptor, usually a platform capability, with a
+ * vendor request node.
+ *
+ * USBD_DESC_BOS_VREQ_DEFINE(bos_vreq_webusb, sizeof(bos_cap_webusb), &bos_cap_webusb,
+ *                           SAMPLE_WEBUSB_VENDOR_CODE, webusb_to_host_cb, NULL);
+ *
+ * @param name      Descriptor node identifier
+ * @param len       Device Capability descriptor length
+ * @param subset    Pointer to a Device Capability descriptor
+ * @param vcode     Vendor request code
+ * @param vto_host  Vendor callback for to-host direction request
+ * @param vto_dev   Vendor callback for to-device direction request
+ */
+#define USBD_DESC_BOS_VREQ_DEFINE(name, len, subset, vcode, vto_host, vto_dev)	\
+	USBD_VREQUEST_DEFINE(vreq_nd_##name, vcode, vto_host, vto_dev);		\
+	static struct usbd_desc_node name = {					\
+		.bos = {							\
+			.utype = USBD_DUT_BOS_VREQ,				\
+			.vreq_nd = &vreq_nd_##name,				\
+		},								\
+		.ptr = subset,							\
+		.bLength = len,							\
+		.bDescriptorType = USB_DESC_BOS,				\
+	}
+
 /**
  * @brief Define USB device support class data
  *

subsys/usb/device_next/usbd_desc.c

@@ -142,6 +142,13 @@ int usbd_add_descriptor(struct usbd_context *const uds_ctx,
 	}
 
 	if (desc_nd->bDescriptorType == USB_DESC_BOS) {
+		if (desc_nd->bos.utype == USBD_DUT_BOS_VREQ) {
+			ret =  usbd_device_register_vreq(uds_ctx, desc_nd->bos.vreq_nd);
+			if (ret) {
+				goto add_descriptor_error;
+			}
+		}
+
 		sys_dlist_append(&uds_ctx->descriptors, &desc_nd->node);
 	}