1 files changed, 40 insertions, 0 deletions

diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index 24649ada08df..adec3d15810a 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -140,6 +140,46 @@ struct device *acpi_get_physical_device(acpi_handle handle)
 
 EXPORT_SYMBOL(acpi_get_physical_device);
 
+/* ToDo: When a PCI bridge is found, return the PCI device behind the bridge
+ *       This should work in general, but did not on a Lenovo T61 for the
+ *       graphics card. But this must be fixed when the PCI device is
+ *       bound and the kernel device struct is attached to the acpi device
+ * Note: A success call will increase reference count by one
+ *       Do call put_device(dev) on the returned device then
+ */
+struct device *acpi_get_physical_pci_device(acpi_handle handle)
+{
+        struct device *dev;
+        long long device_id;
+        acpi_status status;
+
+        status =
+                acpi_evaluate_integer(handle, "_ADR", NULL, &device_id);
+
+        if (ACPI_FAILURE(status))
+                return NULL;
+
+        /* We need to attempt to determine whether the _ADR refers to a
+           PCI device or not. There's no terribly good way to do this,
+           so the best we can hope for is to assume that there'll never
+           be a device in the host bridge */
+        if (device_id >= 0x10000) {
+                /* It looks like a PCI device. Does it exist? */
+                dev = acpi_get_physical_device(handle);
+        } else {
+                /* It doesn't look like a PCI device. Does its parent
+                   exist? */
+                acpi_handle phandle;
+                if (acpi_get_parent(handle, &phandle))
+                        return NULL;
+                dev = acpi_get_physical_device(phandle);
+        }
+        if (!dev)
+                return NULL;
+        return dev;
+}
+EXPORT_SYMBOL(acpi_get_physical_pci_device);
+
 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 {
         struct acpi_device *acpi_dev;