* resources available from it but they will be matched normally using functions
  * provided by their bus types (and analogously for their modalias).
  */
-struct acpi_device *acpi_companion_match(const struct device *dev)
+const struct acpi_device *acpi_companion_match(const struct device *dev)
 {
        struct acpi_device *adev;
 
  * identifiers and a _DSD object with the "compatible" property, use that
  * property to match against the given list of identifiers.
  */
-static bool acpi_of_match_device(struct acpi_device *adev,
+static bool acpi_of_match_device(const struct acpi_device *adev,
                                 const struct of_device_id *of_match_table,
                                 const struct of_device_id **of_id)
 {
        return true;
 }
 
-static bool __acpi_match_device(struct acpi_device *device,
+static bool __acpi_match_device(const struct acpi_device *device,
                                const struct acpi_device_id *acpi_ids,
                                const struct of_device_id *of_ids,
                                const struct acpi_device_id **acpi_id,
 
 }
 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
 
-static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
+static int __acpi_device_modalias(const struct acpi_device *adev, char *buf, int size)
 {
        int len, count;
 
 
 /* --------------------------------------------------------------------------
                      Device Matching and Notification
    -------------------------------------------------------------------------- */
-struct acpi_device *acpi_companion_match(const struct device *dev);
+const struct acpi_device *acpi_companion_match(const struct device *dev);
 int __acpi_device_uevent_modalias(const struct acpi_device *adev,
                                  struct kobj_uevent_env *env);