i2c: Export i2c_match_id() for direct use by device drivers

When there was no other way to match a I2C device to driver i2c_match_id()
was exclusively used.  However, now there are other types of tables which
are commonly supplied, matching on an i2c_device_id table is used less
frequently.  Instead of _always_ calling i2c_match_id() from within the
framework, we only need to do so from drivers which have no other way of
matching.  This patch makes i2c_match_id() available to the aforementioned
device drivers.
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Tested-by: Kieran Bingham <kieran@bingham.xyz>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/i2c-core.c

@@ -676,7 +676,7 @@ static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
 
 /* ------------------------------------------------------------------------- */
 
-static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
+const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
 						const struct i2c_client *client)
 {
 	if (!(id && client))
@@ -689,6 +689,7 @@ static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
 	}
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(i2c_match_id);
 
 static int i2c_device_match(struct device *dev, struct device_driver *drv)
 {

include/linux/i2c.h

@@ -243,6 +243,8 @@ struct i2c_client {
 
 extern struct i2c_client *i2c_verify_client(struct device *dev);
 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
+extern const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
+					const struct i2c_client *client);
 
 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
 {