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>

1 files changed, 37 insertions, 13 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index f2e283426be9..f205b368894b 100644
--- 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;