serial/8250: Add support for RS485 IOCTLs

This patch allow the users of the 8250 infrastructure to define a
handler for RS485 configration.

If no handler is defined the 8250 driver will work as usual.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Alan Cox <alan@linux.intel.com>
--
v2:Change suggested by Alan "One Thousand Gnomes":
- Move rs485 structure further down on the uart_8250_port structure

 drivers/tty/serial/8250/8250_core.c | 39 +++++++++++++++++++++++++++++++++++++
 include/linux/serial_8250.h         |  3 +++
 2 files changed, 42 insertions(+)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index f93649e22c43..6dd671765312 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -96,10 +96,13 @@ struct uart_8250_port {
         unsigned char           msr_saved_flags;
 
         struct uart_8250_dma    *dma;
+        struct serial_rs485     rs485;
 
         /* 8250 specific callbacks */
         int                     (*dl_read)(struct uart_8250_port *);
         void                    (*dl_write)(struct uart_8250_port *, int);
+        int                     (*rs485_config)(struct uart_8250_port *,
+                                                struct serial_rs485 *rs485);
 };
 
 static inline struct uart_8250_port *up_to_u8250p(struct uart_port *up)