tty: serial: 8250_core: allow to overwrite & export serial8250_startup()

The OMAP version of the 8250 can actually use 1:1 serial8250_startup().
However it needs to be extended by a wake up irq which should to be
requested & enabled at ->startup() time and disabled at ->shutdown() time.

v2…v3: properly copy callbacks
v1…v2: add shutdown callback

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 27 insertions, 2 deletions

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 90e0d5e2b7ee..872c020607a8 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1930,7 +1930,7 @@ static void serial8250_put_poll_char(struct uart_port *port,
 
 #endif /* CONFIG_CONSOLE_POLL */
 
-static int serial8250_startup(struct uart_port *port)
+int serial8250_do_startup(struct uart_port *port)
 {
         struct uart_8250_port *up = up_to_u8250p(port);
         unsigned long flags;
@@ -2181,8 +2181,16 @@ dont_test_tx_en:
 
         return 0;
 }
+EXPORT_SYMBOL_GPL(serial8250_do_startup);
 
-static void serial8250_shutdown(struct uart_port *port)
+static int serial8250_startup(struct uart_port *port)
+{
+        if (port->startup)
+                return port->startup(port);
+        return serial8250_do_startup(port);
+}
+
+void serial8250_do_shutdown(struct uart_port *port)
 {
         struct uart_8250_port *up = up_to_u8250p(port);
         unsigned long flags;
@@ -2232,6 +2240,15 @@ static void serial8250_shutdown(struct uart_port *port)
         if (port->irq)
                 serial_unlink_irq_chain(up);
 }
+EXPORT_SYMBOL_GPL(serial8250_do_shutdown);
+
+static void serial8250_shutdown(struct uart_port *port)
+{
+        if (port->shutdown)
+                port->shutdown(port);
+        else
+                serial8250_do_shutdown(port);
+}
 
 static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud)
 {
@@ -3466,6 +3483,10 @@ 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.startup)
+                        uart->port.startup = up->port.startup;
+                if (up->port.shutdown)
+                        uart->port.shutdown = up->port.shutdown;
                 if (up->port.pm)
                         uart->port.pm = up->port.pm;
                 if (up->port.handle_break)
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 6dd671765312..6fc9d7bee05e 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -124,6 +124,8 @@ extern void serial8250_early_out(struct uart_port *port, int offset, int value);
 extern int setup_early_serial8250_console(char *cmdline);
 extern void serial8250_do_set_termios(struct uart_port *port,
                 struct ktermios *termios, struct ktermios *old);
+extern int serial8250_do_startup(struct uart_port *port);
+extern void serial8250_do_shutdown(struct uart_port *port);
 extern void serial8250_do_pm(struct uart_port *port, unsigned int state,
                              unsigned int oldstate);
 extern int fsl8250_handle_irq(struct uart_port *port);
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 8cb267b1fcd5..3bd7d55eebce 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -122,6 +122,8 @@ struct uart_port {
         void                    (*set_termios)(struct uart_port *,
                                                struct ktermios *new,
                                                struct ktermios *old);
+        int                     (*startup)(struct uart_port *port);
+        void                    (*shutdown)(struct uart_port *port);
         int                     (*handle_irq)(struct uart_port *);
         void                    (*pm)(struct uart_port *, unsigned int state,
                                       unsigned int old);