greybus: connection: move legacy-protocol handling to legacy driver

Move legacy protocol and connection handling to the legacy driver.

Rename the former global functions using a common legacy_ prefix.

Note that all legacy protocols suffer from a connection initialisation
race in that the protocol-specific initialisation, which includes
allocation of protocol-specific state containers, can not happen until
*after* the connection has been enabled. This is a major flaw in the
original design that we can now finally address by converting the legacy
protocol drivers into proper bundle (class) drivers.

Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

1 files changed, 103 insertions, 3 deletions

diff --git a/drivers/staging/greybus/legacy.c b/drivers/staging/greybus/legacy.c
index e8d9cb93b831..fd847f42376f 100644
--- a/drivers/staging/greybus/legacy.c
+++ b/drivers/staging/greybus/legacy.c
@@ -9,6 +9,106 @@
 
 #include "greybus.h"
 #include "legacy.h"
+#include "protocol.h"
+
+
+static int legacy_connection_get_version(struct gb_connection *connection)
+{
+	int ret;
+
+	ret = gb_protocol_get_version(connection);
+	if (ret) {
+		dev_err(&connection->hd->dev,
+			"%s: failed to get protocol version: %d\n",
+			connection->name, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int legacy_connection_bind_protocol(struct gb_connection *connection)
+{
+	struct gb_protocol *protocol;
+
+	protocol = gb_protocol_get(connection->protocol_id,
+				   connection->major,
+				   connection->minor);
+	if (!protocol) {
+		dev_err(&connection->hd->dev,
+				"protocol 0x%02x version %u.%u not found\n",
+				connection->protocol_id,
+				connection->major, connection->minor);
+		return -EPROTONOSUPPORT;
+	}
+	connection->protocol = protocol;
+
+	return 0;
+}
+
+static void legacy_connection_unbind_protocol(struct gb_connection *connection)
+{
+	struct gb_protocol *protocol = connection->protocol;
+
+	gb_protocol_put(protocol);
+
+	connection->protocol = NULL;
+}
+
+static int legacy_request_handler(struct gb_operation *operation)
+{
+	struct gb_protocol *protocol = operation->connection->protocol;
+
+	return protocol->request_recv(operation->type, operation);
+}
+
+static int legacy_connection_init(struct gb_connection *connection)
+{
+	gb_request_handler_t handler;
+	int ret;
+
+	ret = legacy_connection_bind_protocol(connection);
+	if (ret)
+		return ret;
+
+	if (connection->protocol->request_recv)
+		handler = legacy_request_handler;
+	else
+		handler = NULL;
+
+	ret = gb_connection_enable(connection, handler);
+	if (ret)
+		goto err_unbind_protocol;
+
+	ret = legacy_connection_get_version(connection);
+	if (ret)
+		goto err_disable;
+
+	ret = connection->protocol->connection_init(connection);
+	if (ret)
+		goto err_disable;
+
+	return 0;
+
+err_disable:
+	gb_connection_disable(connection);
+err_unbind_protocol:
+	legacy_connection_unbind_protocol(connection);
+
+	return ret;
+}
+
+static void legacy_connection_exit(struct gb_connection *connection)
+{
+	if (connection->state == GB_CONNECTION_STATE_DISABLED)
+		return;
+
+	gb_connection_disable(connection);
+
+	connection->protocol->connection_exit(connection);
+
+	legacy_connection_unbind_protocol(connection);
+}
 
 static int legacy_probe(struct gb_bundle *bundle,
 			const struct greybus_bundle_id *id)
@@ -23,7 +123,7 @@ static int legacy_probe(struct gb_bundle *bundle,
 		dev_dbg(&bundle->dev, "enabling connection %s\n",
 				connection->name);
 
-		ret = gb_connection_legacy_init(connection);
+		ret = legacy_connection_init(connection);
 		if (ret)
 			goto err_connections_disable;
 	}
@@ -33,7 +133,7 @@ static int legacy_probe(struct gb_bundle *bundle,
 err_connections_disable:
 	list_for_each_entry_reverse(connection, &bundle->connections,
 							bundle_links) {
-		gb_connection_legacy_exit(connection);
+		legacy_connection_exit(connection);
 	}
 
 	return ret;
@@ -48,7 +148,7 @@ static void legacy_disconnect(struct gb_bundle *bundle)
 
 	list_for_each_entry_reverse(connection, &bundle->connections,
 							bundle_links) {
-		gb_connection_legacy_exit(connection);
+		legacy_connection_exit(connection);
 	}
 }