greybus: begin abstracting connection operations

This is part 1 of abstracting the connection operations into a set
of methods.  This will avoid some big switch statements, but more
importantly this will be needed for supporting multiple versions of
each protocol.

For now only two methods are defined.  The init method is used
to set up the device (or whatever the CPort represents) and the exit
method tears it down.  There may need to be additional operations
added in the future, and once versioning is used we might stash
the version number in this structure as well.

The next patch adds dynamic registratration of these protocol
handlers, and will do away with the switch statement now found
in gb_connection_init().

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/staging/greybus/connection.h b/drivers/staging/greybus/connection.h
index 19dd91dae062..4492d2f67ec4 100644
--- a/drivers/staging/greybus/connection.h
+++ b/drivers/staging/greybus/connection.h
@@ -21,6 +21,15 @@ enum gb_connection_state {
 	GB_CONNECTION_STATE_DESTROYING	= 4,
 };
 
+struct gb_connection;
+typedef int (*gb_connection_init_t)(struct gb_connection *);
+typedef void (*gb_connection_exit_t)(struct gb_connection *);
+
+struct gb_connection_handler {
+	gb_connection_init_t	connection_init;
+	gb_connection_exit_t	connection_exit;
+};
+
 struct gb_connection {
 	struct greybus_host_device	*hd;
 	struct gb_interface		*interface;
@@ -38,6 +47,8 @@ struct gb_connection {
 	atomic_t			op_cycle;
 	struct delayed_work		timeout_work;
 
+	struct gb_connection_handler	*handler;
+
 	void				*private;
 };
 #define to_gb_connection(d) container_of(d, struct gb_connection, dev)