serial: 8250: Expose set_ldisc function

Expose set_ldisc() function so that it can be overridden with a
platform specific implementation.

Signed-off-by: Ed Blake <ed.blake@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_core.c

@@ -830,6 +830,7 @@ static int serial8250_probe(struct platform_device *dev)
 		uart.port.handle_irq	= p->handle_irq;
 		uart.port.handle_break	= p->handle_break;
 		uart.port.set_termios	= p->set_termios;
+		uart.port.set_ldisc	= p->set_ldisc;
 		uart.port.get_mctrl	= p->get_mctrl;
 		uart.port.pm		= p->pm;
 		uart.port.dev		= &dev->dev;
@@ -1023,6 +1024,8 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 		/*  Possibly override set_termios call */
 		if (up->port.set_termios)
 			uart->port.set_termios = up->port.set_termios;
+		if (up->port.set_ldisc)
+			uart->port.set_ldisc = up->port.set_ldisc;
 		if (up->port.get_mctrl)
 			uart->port.get_mctrl = up->port.get_mctrl;
 		if (up->port.set_mctrl)

drivers/tty/serial/8250/8250_port.c

@@ -2693,8 +2693,7 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
 		serial8250_do_set_termios(port, termios, old);
 }
 
-static void
-serial8250_set_ldisc(struct uart_port *port, struct ktermios *termios)
+void serial8250_do_set_ldisc(struct uart_port *port, struct ktermios *termios)
 {
 	if (termios->c_line == N_PPS) {
 		port->flags |= UPF_HARDPPS_CD;
@@ -2710,7 +2709,16 @@ serial8250_set_ldisc(struct uart_port *port, struct ktermios *termios)
 		}
 	}
 }
+EXPORT_SYMBOL_GPL(serial8250_do_set_ldisc);
 
+static void
+serial8250_set_ldisc(struct uart_port *port, struct ktermios *termios)
+{
+	if (port->set_ldisc)
+		port->set_ldisc(port, termios);
+	else
+		serial8250_do_set_ldisc(port, termios);
+}
 
 void serial8250_do_pm(struct uart_port *port, unsigned int state,
 		      unsigned int oldstate)

include/linux/serial_8250.h

@@ -36,6 +36,8 @@ struct plat_serial8250_port {
 	void		(*set_termios)(struct uart_port *,
 			               struct ktermios *new,
 			               struct ktermios *old);
+	void		(*set_ldisc)(struct uart_port *,
+				     struct ktermios *);
 	unsigned int	(*get_mctrl)(struct uart_port *);
 	int		(*handle_irq)(struct uart_port *);
 	void		(*pm)(struct uart_port *, unsigned int state,
@@ -149,6 +151,8 @@ extern int early_serial8250_setup(struct earlycon_device *device,
 					 const char *options);
 extern void serial8250_do_set_termios(struct uart_port *port,
 		struct ktermios *termios, struct ktermios *old);
+extern void serial8250_do_set_ldisc(struct uart_port *port,
+				    struct ktermios *termios);
 extern unsigned int serial8250_do_get_mctrl(struct uart_port *port);
 extern int serial8250_do_startup(struct uart_port *port);
 extern void serial8250_do_shutdown(struct uart_port *port);

include/linux/serial_core.h

@@ -123,6 +123,8 @@ struct uart_port {
 	void			(*set_termios)(struct uart_port *,
 				               struct ktermios *new,
 				               struct ktermios *old);
+	void			(*set_ldisc)(struct uart_port *,
+					     struct ktermios *);
 	unsigned int		(*get_mctrl)(struct uart_port *);
 	void			(*set_mctrl)(struct uart_port *, unsigned int);
 	int			(*startup)(struct uart_port *port);