tty: serial: 8250_core: allow to set ->throttle / ->unthrottle callbacks

The OMAP UART provides support for HW assisted flow control. What is
missing is the support to throttle / unthrottle callbacks which are used
by the omap-serial driver at the moment.
This patch adds the callbacks. It should be safe to add them since they
are only invoked from the serial_core (uart_throttle()) if the feature
flags are set.

Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 204c452a7567..21c2e05c1bc3 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -125,6 +125,8 @@ struct uart_port {
                                                struct ktermios *old);
         int                     (*startup)(struct uart_port *port);
         void                    (*shutdown)(struct uart_port *port);
+        void                    (*throttle)(struct uart_port *port);
+        void                    (*unthrottle)(struct uart_port *port);
         int                     (*handle_irq)(struct uart_port *);
         void                    (*pm)(struct uart_port *, unsigned int state,
                                       unsigned int old);