1 files changed, 117 insertions, 0 deletions
diff --git a/drivers/usb/core/usb-acpi.c b/drivers/usb/core/usb-acpi.c
new file mode 100644
index 000000000000..8947b203d5a4
--- /dev/null
+++ b/drivers/usb/core/usb-acpi.c
@@ -0,0 +1,117 @@
+/*
+ * USB-ACPI glue code
+ *
+ * Copyright 2012 Red Hat <mjg@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation, version 2.
+ *
+ */
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/pci.h>
+#include <acpi/acpi_bus.h>
+
+#include "usb.h"
+
+static int usb_acpi_check_upc(struct usb_device *udev, acpi_handle handle)
+{
+	acpi_status status;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *upc;
+	int ret = 0;
+
+	status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
+
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	upc = buffer.pointer;
+
+	if (!upc || (upc->type != ACPI_TYPE_PACKAGE)
+		|| upc->package.count != 4) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (upc->package.elements[0].integer.value)
+		udev->removable = USB_DEVICE_REMOVABLE;
+	else
+		udev->removable = USB_DEVICE_FIXED;
+
+out:
+	kfree(upc);
+	return ret;
+}
+
+static int usb_acpi_check_pld(struct usb_device *udev, acpi_handle handle)
+{
+	acpi_status status;
+	struct acpi_pld pld;
+
+	status = acpi_get_physical_device_location(handle, &pld);
+
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	if (pld.user_visible)
+		udev->removable = USB_DEVICE_REMOVABLE;
+	else
+		udev->removable = USB_DEVICE_FIXED;
+
+	return 0;
+}
+
+static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
+{
+	struct usb_device *udev;
+	struct device *parent;
+	acpi_handle *parent_handle;
+
+	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)
+		return -ENODEV;
+
+	/*
+	 * PLD will tell us whether a port is removable to the user or
+	 * not. If we don't get an answer from PLD (it's not present
+	 * or it's malformed) then try to infer it from UPC. If a
+	 * device isn't connectable then it's probably not removable.
+	 */
+	if (usb_acpi_check_pld(udev, *handle) != 0)
+		usb_acpi_check_upc(udev, *handle);
+
+	return 0;
+}
+
+static struct acpi_bus_type usb_acpi_bus = {
+	.bus = &usb_bus_type,
+	.find_bridge = NULL,
+	.find_device = usb_acpi_find_device,
+};
+
+int usb_acpi_register(void)
+{
+	return register_acpi_bus_type(&usb_acpi_bus);
+}
+
+void usb_acpi_unregister(void)
+{
+	unregister_acpi_bus_type(&usb_acpi_bus);
+}