usb: split code locating ACPI companion into port and device

In preparation for handling embedded USB devices let's split
usb_acpi_find_companion() into usb_acpi_find_companion_for_device() and
usb_acpi_find_companion_for_port().
Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Rajat Jain <rajatja@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Sukumar Ghorai <sukumar.ghorai@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/usb/core/usb-acpi.c

@@ -139,42 +139,16 @@ static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent,
 	return acpi_find_child_device(parent, raw, false);
 }
 
-static struct acpi_device *usb_acpi_find_companion(struct device *dev)
+static struct acpi_device *
+usb_acpi_get_companion_for_port(struct usb_port *port_dev)
 {
 	struct usb_device *udev;
 	struct acpi_device *adev;
 	acpi_handle *parent_handle;
-
-	/*
-	 * In the ACPI DSDT table, only usb root hub and usb ports are
-	 * acpi device nodes. The hierarchy like following.
-	 * Device (EHC1)
-	 *	Device (HUBN)
-	 *		Device (PR01)
-	 *			Device (PR11)
-	 *			Device (PR12)
-	 *			Device (PR13)
-	 *			...
-	 * So all binding process is divided into two parts. binding
-	 * root hub and usb ports.
-	 */
-	if (is_usb_device(dev)) {
-		udev = to_usb_device(dev);
-		if (udev->parent)
-			return NULL;
-
-		/* root hub is only child (_ADR=0) under its parent, the HC */
-		adev = ACPI_COMPANION(dev->parent);
-		return acpi_find_child_device(adev, 0, false);
-	} else if (is_usb_port(dev)) {
-		struct usb_port *port_dev = to_usb_port(dev);
-		int port1 = port_dev->portnum;
-		struct acpi_pld_info *pld;
-		acpi_handle *handle;
-		acpi_status status;
+	int port1;
 
 	/* Get the struct usb_device point of port's hub */
-		udev = to_usb_device(dev->parent->parent);
+	udev = to_usb_device(port_dev->dev.parent->parent);
 
 	/*
 	 * The root hub ports' parent is the root hub. The non-root-hub
@@ -182,42 +156,79 @@ static struct acpi_device *usb_acpi_find_companion(struct device *dev)
 	 * connected to.
 	 */
 	if (!udev->parent) {
-			struct usb_hcd *hcd = bus_to_hcd(udev->bus);
-			int raw;
-
-			raw = usb_hcd_find_raw_port_number(hcd, port1);
-
-			adev = usb_acpi_find_port(ACPI_COMPANION(&udev->dev),
-						  raw);
-
-			if (!adev)
-				return NULL;
+		adev = ACPI_COMPANION(&udev->dev);
+		port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
+						     port_dev->portnum);
 	} else {
-			parent_handle =
-				usb_get_hub_port_acpi_handle(udev->parent,
+		parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
 							     udev->portnum);
 		if (!parent_handle)
 			return NULL;
 
 		acpi_bus_get_device(parent_handle, &adev);
+		port1 = port_dev->portnum;
+	}
+
+	return usb_acpi_find_port(adev, port1);
+}
 
-			adev = usb_acpi_find_port(adev, port1);
+static struct acpi_device *
+usb_acpi_find_companion_for_port(struct usb_port *port_dev)
+{
+	struct acpi_device *adev;
+	struct acpi_pld_info *pld;
+	acpi_handle *handle;
+	acpi_status status;
 
+	adev = usb_acpi_get_companion_for_port(port_dev);
 	if (!adev)
 		return NULL;
-		}
+
 	handle = adev->handle;
 	status = acpi_get_physical_device_location(handle, &pld);
-		if (ACPI_FAILURE(status) || !pld)
-			return adev;
-
+	if (!ACPI_FAILURE(status) && pld) {
 		port_dev->location = USB_ACPI_LOCATION_VALID
 			| pld->group_token << 8 | pld->group_position;
 		port_dev->connect_type = usb_acpi_get_connect_type(handle, pld);
 		ACPI_FREE(pld);
+	}
 
 	return adev;
-	}
+}
+
+static struct acpi_device *
+usb_acpi_find_companion_for_device(struct usb_device *udev)
+{
+	struct acpi_device *adev;
+
+	if (!udev->parent)
+		return NULL;
+
+	/* root hub is only child (_ADR=0) under its parent, the HC */
+	adev = ACPI_COMPANION(udev->dev.parent);
+	return acpi_find_child_device(adev, 0, false);
+}
+
+
+static struct acpi_device *usb_acpi_find_companion(struct device *dev)
+{
+	/*
+	 * In the ACPI DSDT table, only usb root hub and usb ports are
+	 * acpi device nodes. The hierarchy like following.
+	 * Device (EHC1)
+	 *	Device (HUBN)
+	 *		Device (PR01)
+	 *			Device (PR11)
+	 *			Device (PR12)
+	 *			Device (PR13)
+	 *			...
+	 * So all binding process is divided into two parts. binding
+	 * root hub and usb ports.
+	 */
+	if (is_usb_device(dev))
+		return usb_acpi_find_companion_for_device(to_usb_device(dev));
+	else if (is_usb_port(dev))
+		return usb_acpi_find_companion_for_port(to_usb_port(dev));
 
 	return NULL;
 }