atmel_serial: RS485: receiving enabled when sending data

By default the atmel_serial driver in RS485 mode disables receiving data until
all data in the send buffer has been sent. This flag allows to receive data
even whilst sending data.

Signed-off-by: Bernhard Roth <br@pwrnet.de>
Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/serial.h b/include/linux/serial.h
index ef91406..97ff8e2 100644
--- a/include/linux/serial.h
+++ b/include/linux/serial.h
@@ -211,6 +211,7 @@
 #define SER_RS485_RTS_ON_SEND		(1 << 1)
 #define SER_RS485_RTS_AFTER_SEND	(1 << 2)
 #define SER_RS485_RTS_BEFORE_SEND	(1 << 3)
+#define SER_RS485_RX_DURING_TX		(1 << 4)
 	__u32	delay_rts_before_send;	/* Milliseconds */
 	__u32	delay_rts_after_send;	/* Milliseconds */
 	__u32	padding[5];		/* Memory is cheap, new structs