1 files changed, 100 insertions, 63 deletions

diff --git a/drivers/usb/core/usb-acpi.c b/drivers/usb/core/usb-acpi.c
index e221861b3187..9043d7242d67 100644
--- a/drivers/usb/core/usb-acpi.c
+++ b/drivers/usb/core/usb-acpi.c
@@ -139,86 +139,123 @@ 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;
+	int port1;
+
+	/* Get the struct usb_device point of port's hub */
+	udev = to_usb_device(port_dev->dev.parent->parent);
 
 	/*
-	 * 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.
+	 * The root hub ports' parent is the root hub. The non-root-hub
+	 * ports' parent is the parent hub port which the hub is
+	 * connected to.
 	 */
-	if (is_usb_device(dev)) {
-		udev = to_usb_device(dev);
-		if (udev->parent)
+	if (!udev->parent) {
+		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,
+							     udev->portnum);
+		if (!parent_handle)
 			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;
-
-		/* Get the struct usb_device point of port's hub */
-		udev = to_usb_device(dev->parent->parent);
-
-		/*
-		 * The root hub ports' parent is the root hub. The non-root-hub
-		 * ports' parent is the parent hub port which the hub is
-		 * 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;
-		} else {
-			parent_handle =
-				usb_get_hub_port_acpi_handle(udev->parent,
-				udev->portnum);
-			if (!parent_handle)
-				return NULL;
-
-			acpi_bus_get_device(parent_handle, &adev);
-
-			adev = usb_acpi_find_port(adev, port1);
-
-			if (!adev)
-				return NULL;
-		}
-		handle = adev->handle;
-		status = acpi_get_physical_device_location(handle, &pld);
-		if (ACPI_FAILURE(status) || !pld)
-			return adev;
+		acpi_bus_get_device(parent_handle, &adev);
+		port1 = port_dev->portnum;
+	}
 
+	return 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) {
 		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;
+	return adev;
+}
+
+static struct acpi_device *
+usb_acpi_find_companion_for_device(struct usb_device *udev)
+{
+	struct acpi_device *adev;
+	struct usb_port *port_dev;
+	struct usb_hub *hub;
+
+	if (!udev->parent) {
+		/* 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);
 	}
 
+	hub = usb_hub_to_struct_hub(udev->parent);
+	if (!hub)
+		return NULL;
+
+	/*
+	 * This is an embedded USB device connected to a port and such
+	 * devices share port's ACPI companion.
+	 */
+	port_dev = hub->ports[udev->portnum - 1];
+	return usb_acpi_get_companion_for_port(port_dev);
+}
+
+static struct acpi_device *usb_acpi_find_companion(struct device *dev)
+{
+	/*
+	 * The USB hierarchy like following:
+	 *
+	 * Device (EHC1)
+	 *	Device (HUBN)
+	 *		Device (PR01)
+	 *			Device (PR11)
+	 *			Device (PR12)
+	 *				Device (FN12)
+	 *				Device (FN13)
+	 *			Device (PR13)
+	 *			...
+	 * where HUBN is root hub, and PRNN are USB ports and devices
+	 * connected to them, and FNNN are individualk functions for
+	 * connected composite USB devices. PRNN and FNNN may contain
+	 * _CRS and other methods describing sideband resources for
+	 * the connected device.
+	 *
+	 * On the kernel side both root hub and embedded USB devices are
+	 * represented as instances of usb_device structure, and ports
+	 * are represented as usb_port structures, so the whole process
+	 * is split into 2 parts: finding companions for devices and
+	 * finding companions for ports.
+	 *
+	 * Note that we do not handle individual functions of composite
+	 * devices yet, for that we would need to assign companions to
+	 * devices corresponding to USB interfaces.
+	 */
+	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;
 }