CRIS: ioctl for getting RS485 information

Add ioctl to CRIS serial driver to get RS485 data from user-space.
Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>

arch/cris/include/asm/ioctls.h

@@ -77,6 +77,7 @@
 #define TIOCSERSETRS485	0x5461  /* enable rs-485 (deprecated) */
 #define TIOCSERWRRS485	0x5462  /* write rs-485 */
 #define TIOCSRS485	0x5463  /* enable rs-485 */
+#define TIOCGRS485	0x542E  /* get rs-485 */
 
 /* Used for packet mode */
 #define TIOCPKT_DATA		 0

drivers/serial/crisv10.c

@@ -3724,6 +3724,17 @@ rs_ioctl(struct tty_struct *tty, struct file * file,
 		return e100_enable_rs485(tty, &rs485data);
 	}
 
+	case TIOCGRS485:
+	{
+		struct serial_rs485 *rs485data =
+			&(((struct e100_serial *)tty->driver_data)->rs485);
+		/* This is the ioctl to get RS485 data from user-space */
+		if (copy_to_user((struct serial_rs485 *) arg,
+					rs485data,
+					sizeof(serial_rs485)))
+			return -EFAULT;
+		break;
+	}
 
 	case TIOCSERWRRS485:
 	{