ACPI: Provide generic functions for matching ACPI device nodes

Introduce function acpi_match_device() allowing callers to match
struct device objects with populated acpi_handle fields against
arrays of ACPI device IDs.  Also introduce function
acpi_driver_match_device() using acpi_match_device() internally and
allowing callers to match a struct device object against an array of
ACPI device IDs provided by a device driver.

Additionally, introduce macro ACPI_PTR() that may be used by device
drivers to escape pointers to data structures whose definitions
depend on CONFIG_ACPI.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 90be989..48761cb 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -26,6 +26,7 @@
 #define _LINUX_ACPI_H
 
 #include <linux/ioport.h>	/* for struct resource */
+#include <linux/device.h>
 
 #ifdef	CONFIG_ACPI
 
@@ -364,6 +365,17 @@
 extern int acpi_nvs_for_each_region(int (*func)(__u64, __u64, void *),
 				    void *data);
 
+const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
+					       const struct device *dev);
+
+static inline bool acpi_driver_match_device(struct device *dev,
+					    const struct device_driver *drv)
+{
+	return !!acpi_match_device(drv->acpi_match_table, dev);
+}
+
+#define ACPI_PTR(_ptr)	(_ptr)
+
 #else	/* !CONFIG_ACPI */
 
 #define acpi_disabled 1
@@ -418,6 +430,22 @@
 	return 0;
 }
 
+struct acpi_device_id;
+
+static inline const struct acpi_device_id *acpi_match_device(
+	const struct acpi_device_id *ids, const struct device *dev)
+{
+	return NULL;
+}
+
+static inline bool acpi_driver_match_device(struct device *dev,
+					    const struct device_driver *drv)
+{
+	return false;
+}
+
+#define ACPI_PTR(_ptr)	(NULL)
+
 #endif	/* !CONFIG_ACPI */
 
 #ifdef CONFIG_ACPI