ACPI: add acpi_bus_get_parent() and remove "parent" arguments

This patch adds acpi_bus_get_parent(), which ascends the namespace until
it finds a parent with an acpi_device.

Then we use acpi_bus_get_parent() in acpi_add_single_object(), so callers
don't have to figure out or keep track of the parent acpi_device.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index f2e2834..f205b36 100644 (file)
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -662,6 +662,33 @@ EXPORT_SYMBOL(acpi_bus_unregister_driver);
 /* --------------------------------------------------------------------------
                                  Device Enumeration
    -------------------------------------------------------------------------- */
+static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
+{
+       acpi_status status;
+       int ret;
+       struct acpi_device *device;
+
+       /*
+        * Fixed hardware devices do not appear in the namespace and do not
+        * have handles, but we fabricate acpi_devices for them, so we have
+        * to deal with them specially.
+        */
+       if (handle == NULL)
+               return acpi_root;
+
+       do {
+               status = acpi_get_parent(handle, &handle);
+               if (status == AE_NULL_ENTRY)
+                       return NULL;
+               if (ACPI_FAILURE(status))
+                       return acpi_root;
+
+               ret = acpi_bus_get_device(handle, &device);
+               if (ret == 0)
+                       return device;
+       } while (1);
+}
+
 acpi_status
 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
 {
@@ -1217,10 +1244,9 @@ static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
        return 0;
 }
 
-static int
-acpi_add_single_object(struct acpi_device **child,
-                      struct acpi_device *parent, acpi_handle handle, int type,
-                       struct acpi_bus_ops *ops)
+static int acpi_add_single_object(struct acpi_device **child,
+                                 acpi_handle handle, int type,
+                                 struct acpi_bus_ops *ops)
 {
        int result;
        struct acpi_device *device;
@@ -1234,7 +1260,7 @@ acpi_add_single_object(struct acpi_device **child,
 
        device->device_type = type;
        device->handle = handle;
-       device->parent = parent;
+       device->parent = acpi_bus_get_parent(handle);
        device->bus_ops = *ops; /* workround for not call .start */
 
        acpi_device_get_busid(device);
@@ -1434,8 +1460,8 @@ static int acpi_bus_scan(struct acpi_device *start, struct acpi_bus_ops *ops)
                }
 
                if (ops->acpi_op_add)
-                       status = acpi_add_single_object(&child, parent,
-                               chandle, type, ops);
+                       status = acpi_add_single_object(&child, chandle, type,
+                                                       ops);
                else
                        status = acpi_bus_get_device(chandle, &child);
 
@@ -1488,7 +1514,7 @@ acpi_bus_add(struct acpi_device **child,
        memset(&ops, 0, sizeof(ops));
        ops.acpi_op_add = 1;
 
-       result = acpi_add_single_object(child, parent, handle, type, &ops);
+       result = acpi_add_single_object(child, handle, type, &ops);
        if (!result)
                result = acpi_bus_scan(*child, &ops);
 
@@ -1584,15 +1610,13 @@ static int acpi_bus_scan_fixed(void)
         * Enumerate all fixed-feature devices.
         */
        if ((acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON) == 0) {
-               result = acpi_add_single_object(&device, acpi_root,
-                                               NULL,
+               result = acpi_add_single_object(&device, NULL,
                                                ACPI_BUS_TYPE_POWER_BUTTON,
                                                &ops);
        }
 
        if ((acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
-               result = acpi_add_single_object(&device, acpi_root,
-                                               NULL,
+               result = acpi_add_single_object(&device, NULL,
                                                ACPI_BUS_TYPE_SLEEP_BUTTON,
                                                &ops);
        }
@@ -1618,7 +1642,7 @@ int __init acpi_scan_init(void)
        /*
         * Create the root device in the bus's device tree
         */
-       result = acpi_add_single_object(&acpi_root, NULL, ACPI_ROOT_OBJECT,
+       result = acpi_add_single_object(&acpi_root, ACPI_ROOT_OBJECT,
                                        ACPI_BUS_TYPE_SYSTEM, &ops);
        if (result)
                goto Done;