i2c: export i2c_client_type structure

i2c bus has 2 different types of device belonging to the same bus and
bus notifiers use device type to distinguish between adapters and clients.
Previously we only had i2c_adapter_type exported, which made code wanting
to work with i2c_client devices test for type not equal to adapter type.
This unfortunately is not safe if we ever add another type to the bus,
so let's export i2c_client_type as well.
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/i2c/i2c-core.c

@@ -74,7 +74,6 @@
 static DEFINE_MUTEX(core_lock);
 static DEFINE_IDR(i2c_adapter_idr);
 
-static struct device_type i2c_client_type;
 static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
 
 static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE;
@@ -1097,11 +1096,12 @@ struct bus_type i2c_bus_type = {
 };
 EXPORT_SYMBOL_GPL(i2c_bus_type);
 
-static struct device_type i2c_client_type = {
+struct device_type i2c_client_type = {
 	.groups		= i2c_dev_groups,
 	.uevent		= i2c_device_uevent,
 	.release	= i2c_client_dev_release,
 };
+EXPORT_SYMBOL_GPL(i2c_client_type);
 
 
 /**

include/linux/i2c.h

@@ -38,6 +38,7 @@
 
 extern struct bus_type i2c_bus_type;
 extern struct device_type i2c_adapter_type;
+extern struct device_type i2c_client_type;
 
 /* --- General options ------------------------------------------------	*/