serial: 8250_port: export serial8250_rpm_{get|put}_tx()

The following fix of runtime PM use in DMA mode requires at least
serial8250_rpm_put_tx() to be available. Export both calls.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250.h

@@ -129,8 +129,13 @@ static inline void serial_dl_write(struct uart_8250_port *up, int value)
 }
 
 struct uart_8250_port *serial8250_get_port(int line);
+
 void serial8250_rpm_get(struct uart_8250_port *p);
 void serial8250_rpm_put(struct uart_8250_port *p);
+
+void serial8250_rpm_get_tx(struct uart_8250_port *p);
+void serial8250_rpm_put_tx(struct uart_8250_port *p);
+
 int serial8250_em485_init(struct uart_8250_port *p);
 void serial8250_em485_destroy(struct uart_8250_port *p);
 

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

@@ -636,7 +636,7 @@ EXPORT_SYMBOL_GPL(serial8250_em485_destroy);
  * once and disable_runtime_pm_tx() will still disable RPM because the fifo is
  * empty and the HW can idle again.
  */
-static void serial8250_rpm_get_tx(struct uart_8250_port *p)
+void serial8250_rpm_get_tx(struct uart_8250_port *p)
 {
 	unsigned char rpm_active;
 
@@ -648,8 +648,9 @@ static void serial8250_rpm_get_tx(struct uart_8250_port *p)
 		return;
 	pm_runtime_get_sync(p->port.dev);
 }
+EXPORT_SYMBOL_GPL(serial8250_rpm_get_tx);
 
-static void serial8250_rpm_put_tx(struct uart_8250_port *p)
+void serial8250_rpm_put_tx(struct uart_8250_port *p)
 {
 	unsigned char rpm_active;
 
@@ -662,6 +663,7 @@ static void serial8250_rpm_put_tx(struct uart_8250_port *p)
 	pm_runtime_mark_last_busy(p->port.dev);
 	pm_runtime_put_autosuspend(p->port.dev);
 }
+EXPORT_SYMBOL_GPL(serial8250_rpm_put_tx);
 
 /*
  * IER sleep support.  UARTs which have EFRs need the "extended