subsys: usb: host: support multiple devices under hub

When hub is used, need to consider about multiple
devices are attached.

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

Author: AidenHu

subsys/usb/host/usbh_core.c

@@ -49,29 +49,35 @@ static int usbh_event_carrier(const struct device *dev,
 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");
-	if (ctx->root != NULL) {
-		LOG_ERR("Device already connected");
-		usbh_device_free(ctx->root);
-		ctx->root = NULL;
-	}
 
-	ctx->root = usbh_device_alloc(ctx);
-	if (ctx->root == NULL) {
+	udev = usbh_device_alloc(ctx);
+	if (udev == NULL) {
 		LOG_ERR("Failed allocate new device");
 		return;
 	}
 
-	ctx->root->state = USB_STATE_DEFAULT;
+	udev->state = USB_STATE_DEFAULT;
 
 	if (event->type == UHC_EVT_DEV_CONNECTED_HS) {
-		ctx->root->speed = USB_SPEED_SPEED_HS;
+		udev->speed = USB_SPEED_SPEED_HS;
 	} else {
-		ctx->root->speed = USB_SPEED_SPEED_FS;
+		udev->speed = USB_SPEED_SPEED_FS;
+	}
+
+	k_mutex_lock(&ctx->mutex, K_FOREVER);
+	sys_dlist_append(&ctx->udevs, &udev->node);
+
+	if (ctx->root == NULL) {
+		ctx->root = udev;
 	}
+	k_mutex_unlock(&ctx->mutex);
 
-	if (usbh_device_init(ctx->root)) {
+	if (usbh_device_init(udev)) {
 		LOG_ERR("Failed to reset new USB device");
+		sys_dlist_remove(&udev->node);
 	}
 
 	usbh_class_probe_device(ctx->root);

subsys/usb/host/usbh_device.c

@@ -452,6 +452,7 @@ int usbh_device_init(struct usb_device *const udev)
 	struct usbh_context *const uhs_ctx = udev->ctx;
 	uint8_t new_addr;
 	int err;
+	uint8_t device_count = 0;
 
 	if (udev->state != USB_STATE_DEFAULT) {
 		LOG_ERR("USB device is not in default state");
@@ -464,11 +465,17 @@ int usbh_device_init(struct usb_device *const udev)
 		return err;
 	}
 
-	/* FIXME: The port to which the device is connected should be reset. */
-	err = uhc_bus_reset(uhs_ctx->dev);
-	if (err) {
-		LOG_ERR("Failed to signal bus reset");
-		return err;
+	k_mutex_lock(&uhs_ctx->mutex, K_FOREVER);
+	device_count = sys_dlist_len(&uhs_ctx->udevs);
+	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;
+		}
 	}
 
 	/*