subsys: usb: host: refine connect/disconnect handling

Add two functions:
usbh_connect_device() for device connection
usbh_disconnect_device() for device disconnection

These functions centralize the logic for device attach/detach,
including class probe and remove handling. They can be invoked
by the hub class as well as dev_connected_handler and
dev_removed_handler, improving code clarity and reuse.

Signed-off-by: Aiden Hu <[email protected]>

Author: AidenHu

subsys/usb/host/usbh_core.c

@@ -12,8 +12,6 @@
 #include <zephyr/sys/iterable_sections.h>
 #include <zephyr/usb/usbh.h>
 
-#include "usbh_class.h"
-#include "usbh_class_api.h"
 #include "usbh_device.h"
 #include "usbh_internal.h"
 
@@ -45,53 +43,35 @@ static int usbh_event_carrier(const struct device *dev,
 
 	return err;
 }
+
 static void dev_connected_handler(struct usbh_context *const ctx,
 				  const struct uhc_event *const event)
 {
 	struct usb_device *udev;
-
-	LOG_DBG("Device connected event");
-
-	udev = usbh_device_alloc(ctx);
-	if (udev == NULL) {
-		LOG_ERR("Failed allocate new device");
-		return;
-	}
-
-	udev->state = USB_STATE_DEFAULT;
+	uint8_t speed;
 
 	if (event->type == UHC_EVT_DEV_CONNECTED_HS) {
-		udev->speed = USB_SPEED_SPEED_HS;
+		speed = USB_SPEED_SPEED_HS;
 	} else {
-		udev->speed = USB_SPEED_SPEED_FS;
+		speed = USB_SPEED_SPEED_FS;
 	}
 
-	k_mutex_lock(&ctx->mutex, K_FOREVER);
-	sys_dlist_append(&ctx->udevs, &udev->node);
-	k_mutex_unlock(&ctx->mutex);
-
-	if (usbh_device_init(udev)) {
-		LOG_ERR("Failed to reset new USB device");
-		sys_dlist_remove(&udev->node);
+	udev = usbh_connect_device(ctx, speed);
+	if (udev == NULL) {
+		return;
 	}
-
-	usbh_class_probe_device(usbh_device_get_root(ctx));
 }
 
 static void dev_removed_handler(struct usbh_context *const ctx)
 {
 	struct usb_device *udev = NULL;
 
 	udev = usbh_device_get_root(ctx);
-
 	if (udev) {
-		usbh_class_remove_all(udev);
-		usbh_device_free(udev);
-		LOG_DBG("Device removed");
+		usbh_disconnect_device(ctx, udev);
 	} else {
 		LOG_DBG("Spurious device removed event");
 	}
-	/* TODO: handle remove for all of classes for the unattached device */
 }
 
 static int discard_ep_request(struct usbh_context *const ctx,

subsys/usb/host/usbh_device.c

@@ -9,6 +9,8 @@
 
 #include "usbh_device.h"
 #include "usbh_ch9.h"
+#include "usbh_class.h"
+#include "usbh_class_api.h"
 
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(usbh_dev, CONFIG_USBH_LOG_LEVEL);
@@ -475,6 +477,47 @@ bool usbh_device_is_root(struct usbh_context *const ctx,
 	return sys_dlist_peek_head(&ctx->udevs) == &udev->node;
 }
 
+struct usb_device *usbh_connect_device(struct usbh_context *const ctx,
+					    uint8_t speed)
+{
+	struct usb_device *udev;
+
+	LOG_DBG("Device connected event");
+
+	/* Allocate new device */
+	udev = usbh_device_alloc(ctx);
+	if (udev == NULL) {
+		LOG_ERR("Failed allocate new device");
+		return NULL;
+	}
+
+	udev->state = USB_STATE_DEFAULT;
+	udev->speed = speed;
+
+	if (usbh_device_init(udev)) {
+		LOG_ERR("Failed to init new USB device");
+		usbh_device_free(udev);
+		return NULL;
+	}
+
+	usbh_class_probe_device(udev);
+
+	return udev;
+}
+
+void usbh_disconnect_device(struct usbh_context *ctx, struct usb_device *udev)
+{
+	if (!ctx || !udev) {
+		return;
+	}
+
+	usbh_class_remove_all(udev);
+
+	usbh_device_free(udev);
+
+	LOG_DBG("Device removed");
+}
+
 int usbh_device_init(struct usb_device *const udev)
 {
 	struct usbh_context *const uhs_ctx = udev->ctx;
@@ -505,16 +548,6 @@ int usbh_device_init(struct usb_device *const udev)
 			return err;
 		}
 	}
-	k_mutex_unlock(&uhs_ctx->mutex);
-
-	/* Only reset bus if this is the root device */
-	if (device_count == 1U) {
-		err = uhc_bus_reset(uhs_ctx->dev);
-		if (err) {
-			LOG_ERR("Failed to signal bus reset");
-			return err;
-		}
-	}
 
 	/*
 	 * Limit mps0 to the minimum supported by full-speed devices until the

subsys/usb/host/usbh_device.h

@@ -43,6 +43,12 @@ struct usb_device *usbh_device_get_root(struct usbh_context *const ctx);
 bool usbh_device_is_root(struct usbh_context *const ctx,
 			struct usb_device *const udev);
 
+/* Connect a new USB device */
+struct usb_device *usbh_connect_device(struct usbh_context *const ctx,
+				       uint8_t device_speed);
+/* Disconnect USB device */
+void usbh_disconnect_device(struct usbh_context *ctx, struct usb_device *udev);
+
 /* Wrappers around to avoid glue UHC calls. */
 static inline struct uhc_transfer *usbh_xfer_alloc(struct usb_device *udev,
 						   const uint8_t ep,