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path: root/drivers/usb/core/usb-acpi.c
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Diffstat (limited to 'drivers/usb/core/usb-acpi.c')
-rw-r--r--drivers/usb/core/usb-acpi.c117
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 00000000000..8947b203d5a
--- /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);
+}