usb/acpi: Bind ACPI node to USB port, not usb_device.

In the ACPI DSDT table, only usb root hub and usb ports are ACPI device
nodes.  Originally, we bound the usb port's ACPI node to the usb device
attached to the port.  However, we want to access those ACPI port
methods when the port is empty, and there's no usb_device associated
with that port.

Now that the usb port is a real device, we can bind the port's ACPI node
to struct usb_port instead.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 52 insertions, 15 deletions

diff --git a/drivers/usb/core/usb-acpi.c b/drivers/usb/core/usb-acpi.c
index 8947b203d5a4..47197bf0b28d 100644
--- a/drivers/usb/core/usb-acpi.c
+++ b/drivers/usb/core/usb-acpi.c
@@ -70,22 +70,59 @@ static int usb_acpi_check_pld(struct usb_device *udev, acpi_handle handle)
 static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
 {
 	struct usb_device *udev;
-	struct device *parent;
 	acpi_handle *parent_handle;
+	int port_num;
 
-	if (!is_usb_device(dev))
-		return -ENODEV;
-
-	udev = to_usb_device(dev);
-	parent = dev->parent;
-	parent_handle = DEVICE_ACPI_HANDLE(parent);
-
-	if (!parent_handle)
-		return -ENODEV;
-
-	*handle = acpi_get_child(parent_handle, udev->portnum);
-
-	if (!*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 -ENODEV;
+		/* root hub's parent is the usb hcd. */
+		parent_handle = DEVICE_ACPI_HANDLE(dev->parent);
+		*handle = acpi_get_child(parent_handle, udev->portnum);
+		if (!*handle)
+			return -ENODEV;
+		return 0;
+	} else if (is_usb_port(dev)) {
+		sscanf(dev_name(dev), "port%d", &port_num);
+		/* 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) {
+			*handle = acpi_get_child(DEVICE_ACPI_HANDLE(&udev->dev),
+				port_num);
+			if (!*handle)
+				return -ENODEV;
+		} else {
+			parent_handle =
+				usb_get_hub_port_acpi_handle(udev->parent,
+				udev->portnum);
+			if (!parent_handle)
+				return -ENODEV;
+
+			*handle = acpi_get_child(parent_handle,	port_num);
+			if (!*handle)
+				return -ENODEV;
+		}
+	} else
 		return -ENODEV;
 
 	/*
@@ -102,7 +139,7 @@ static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
 
 static struct acpi_bus_type usb_acpi_bus = {
 	.bus = &usb_bus_type,
-	.find_bridge = NULL,
+	.find_bridge = usb_acpi_find_device,
 	.find_device = usb_acpi_find_device,
 };