1 files changed, 81 insertions, 5 deletions

diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 8f07b0516100..62368c4ed37a 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -398,6 +398,52 @@ int usb_for_each_dev(void *data, int (*fn)(struct usb_device *, void *))
 }
 EXPORT_SYMBOL_GPL(usb_for_each_dev);
 
+struct each_hub_arg {
+	void *data;
+	int (*fn)(struct device *, void *);
+};
+
+static int __each_hub(struct usb_device *hdev, void *data)
+{
+	struct each_hub_arg *arg = (struct each_hub_arg *)data;
+	struct usb_hub *hub;
+	int ret = 0;
+	int i;
+
+	hub = usb_hub_to_struct_hub(hdev);
+	if (!hub)
+		return 0;
+
+	mutex_lock(&usb_port_peer_mutex);
+
+	for (i = 0; i < hdev->maxchild; i++) {
+		ret = arg->fn(&hub->ports[i]->dev, arg->data);
+		if (ret)
+			break;
+	}
+
+	mutex_unlock(&usb_port_peer_mutex);
+
+	return ret;
+}
+
+/**
+ * usb_for_each_port - interate over all USB ports in the system
+ * @data: data pointer that will be handed to the callback function
+ * @fn: callback function to be called for each USB port
+ *
+ * Iterate over all USB ports and call @fn for each, passing it @data. If it
+ * returns anything other than 0, we break the iteration prematurely and return
+ * that value.
+ */
+int usb_for_each_port(void *data, int (*fn)(struct device *, void *))
+{
+	struct each_hub_arg arg = {data, fn};
+
+	return usb_for_each_dev(&arg, __each_hub);
+}
+EXPORT_SYMBOL_GPL(usb_for_each_port);
+
 /**
  * usb_release_dev - free a usb device structure when all users of it are finished.
  * @dev: device that's been disconnected
@@ -748,6 +794,38 @@ void usb_put_intf(struct usb_interface *intf)
 }
 EXPORT_SYMBOL_GPL(usb_put_intf);
 
+/**
+ * usb_intf_get_dma_device - acquire a reference on the usb interface's DMA endpoint
+ * @intf: the usb interface
+ *
+ * While a USB device cannot perform DMA operations by itself, many USB
+ * controllers can. A call to usb_intf_get_dma_device() returns the DMA endpoint
+ * for the given USB interface, if any. The returned device structure must be
+ * released with put_device().
+ *
+ * See also usb_get_dma_device().
+ *
+ * Returns: A reference to the usb interface's DMA endpoint; or NULL if none
+ *          exists.
+ */
+struct device *usb_intf_get_dma_device(struct usb_interface *intf)
+{
+	struct usb_device *udev = interface_to_usbdev(intf);
+	struct device *dmadev;
+
+	if (!udev->bus)
+		return NULL;
+
+	dmadev = get_device(udev->bus->sysdev);
+	if (!dmadev || !dmadev->dma_mask) {
+		put_device(dmadev);
+		return NULL;
+	}
+
+	return dmadev;
+}
+EXPORT_SYMBOL_GPL(usb_intf_get_dma_device);
+
 /*			USB device locking
  *
  * USB devices and interfaces are locked using the semaphore in their
@@ -950,17 +1028,15 @@ static struct notifier_block usb_bus_nb = {
 	.notifier_call = usb_bus_notify,
 };
 
-static struct dentry *usb_devices_root;
-
 static void usb_debugfs_init(void)
 {
-	usb_devices_root = debugfs_create_file("devices", 0444, usb_debug_root,
-					       NULL, &usbfs_devices_fops);
+	debugfs_create_file("devices", 0444, usb_debug_root, NULL,
+			    &usbfs_devices_fops);
 }
 
 static void usb_debugfs_cleanup(void)
 {
-	debugfs_remove(usb_devices_root);
+	debugfs_remove(debugfs_lookup("devices", usb_debug_root));
 }
 
 /*