greybus: firmware: Send AP-ready operation

Module's Bootrom needs a way to know (currently), when to start sending
requests to the AP. The version request is sent before connection_init()
routine is called, and if the module sends the request right after
receiving version request, the connection->private field will be NULL.

Fix this TEMPORARILY by sending an AP_READY request.
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/firmware.c

@@ -165,6 +165,7 @@ static int gb_firmware_request_recv(u8 type, struct gb_operation *op)
 static int gb_firmware_connection_init(struct gb_connection *connection)
 {
 	struct gb_firmware *firmware;
+	int ret;
 
 	firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 	if (!firmware)
@@ -173,6 +174,20 @@ static int gb_firmware_connection_init(struct gb_connection *connection)
 	firmware->connection = connection;
 	connection->private = firmware;
 
+	/*
+	 * Module's Bootrom needs a way to know (currently), when to start
+	 * sending requests to the AP. The version request is sent before this
+	 * routine is called, and if the module sends the request right after
+	 * receiving version request, the connection->private field will be
+	 * NULL.
+	 *
+	 * Fix this TEMPORARILY by sending an AP_READY request.
+	 */
+	ret = gb_operation_sync(connection, GB_FIRMWARE_TYPE_AP_READY, NULL, 0,
+				NULL, 0);
+	if (ret)
+		dev_err(&connection->dev, "Failed to send AP READY (%d)\n", ret);
+
 	return 0;
 }
 

drivers/staging/greybus/greybus_protocols.h

@@ -155,6 +155,7 @@ struct gb_control_disconnected_request {
 #define GB_FIRMWARE_TYPE_FIRMWARE_SIZE		0x02
 #define GB_FIRMWARE_TYPE_GET_FIRMWARE		0x03
 #define GB_FIRMWARE_TYPE_READY_TO_BOOT		0x04
+#define GB_FIRMWARE_TYPE_AP_READY		0x05	/* Request with no-payload */
 
 /* Greybus firmware boot stages */
 #define GB_FIRMWARE_BOOT_STAGE_ONE		0x01 /* Reserved for the boot ROM */