[PATCH resend] serial: of-serial: fetch line number from DT

[Lucas Stach <dev-8ppwABl0HbeELgA04lAiVw@public.gmane.org>]

The general agreed way to specify a fixed line number
for a serial console is to provide a "serial" alias
in the devicetree. Start parsing this property in
of_serial.

Signed-off-by: Lucas Stach <dev-8ppwABl0HbeELgA04lAiVw@public.gmane.org>
Acked-by: Olof Johansson <olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org>
---
As 3.16-rc6 landed the fix to avoid the regression that this patch
was causing on Tegra it should be safe to reapply it.
---
 drivers/tty/serial/of_serial.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index 8bc2563..920a831 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -101,6 +101,10 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 	if (of_property_read_u32(np, "fifo-size", &prop) == 0)
 		port->fifosize = prop;
 
+	/* Check for a fixed line number */
+	if ((ret = of_alias_get_id(np, "serial")) >= 0)
+		port->line = ret;
+
 	port->irq = irq_of_parse_and_map(np, 0);
 	port->iotype = UPIO_MEM;
 	if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
-- 
2.1.0