Commit ac1c2840 authored by Alex Elder's avatar Alex Elder Committed by Greg Kroah-Hartman
Browse files

greybus: loopback: support module-initiated requests 



There's no reason we can't support loopback pings or transfers
initiated by the module.  Allow it.

Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@google.com>
parent 48cc8b8b

drivers/staging/greybus/loopback.c

+43 −1
Original line number Diff line number Diff line
@@ -242,6 +242,48 @@ static int gb_loopback_ping(struct gb_loopback *gb, struct timeval *tping) 
	return retval;

}



static int gb_loopback_request_recv(u8 type, struct gb_operation *operation)

{

	struct gb_connection *connection = operation->connection;

	struct gb_loopback_transfer_request *request;

	struct gb_loopback_transfer_response *response;

	u32 len;



	/* By convention, the AP initiates the version operation */

	switch (type) {

	case GB_LOOPBACK_TYPE_PROTOCOL_VERSION:

		dev_err(&connection->dev,

			"module-initiated version operation\n");

		return -EINVAL;

	case GB_LOOPBACK_TYPE_PING:

		return 0;

	case GB_LOOPBACK_TYPE_TRANSFER:

		if (operation->request->payload_size < sizeof(*request)) {

			dev_err(&connection->dev,

				"transfer request too small (%zu < %zu)\n",

				operation->request->payload_size,

				sizeof(*request));

			return -EINVAL;	/* -EMSGSIZE */

		}

		request = operation->request->payload;

		len = le32_to_cpu(request->len);

		if (len) {

			if (!gb_operation_response_alloc(operation, len)) {

				dev_err(&connection->dev,

					"error allocating response\n");

				return -ENOMEM;

			}

			response = operation->response->payload;

			memcpy(response->data, request->data, len);

		}

		return 0;

	default:

		dev_err(&connection->dev,

			"unsupported request: %hhu\n", type);

		return -EINVAL;

	}

}



static void gb_loopback_reset_stats(struct gb_loopback *gb)

{

	struct gb_loopback_stats reset = {
@@ -397,7 +439,7 @@ static struct gb_protocol loopback_protocol = { 
	.minor			= GB_LOOPBACK_VERSION_MINOR,

	.connection_init	= gb_loopback_connection_init,

	.connection_exit	= gb_loopback_connection_exit,

	.request_recv		= NULL,	/* no incoming requests */

	.request_recv		= gb_loopback_request_recv,

};



gb_protocol_driver(&loopback_protocol);