[PATCH v2 08/18] serial: intel: Get serial id from dts

[Songjun Wu]

Get serial id from dts.

"#ifdef CONFIG_LANTIQ" preprocessor is used because LTQ_EARLY_ASC
macro is defined in lantiq_soc.h.
lantiq_soc.h is in arch path for legacy product support.

arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h

If "#ifdef preprocessor" is changed to
"if (IS_ENABLED(CONFIG_LANTIQ))", when CONFIG_LANTIQ is not enabled,
code using LTQ_EARLY_ASC is compiled.
Compilation will fail for no LTQ_EARLY_ASC defined.

Signed-off-by: Songjun Wu <songjun.wu@xxxxxxxxxxxxxxx>
---

Changes in v2: None

 drivers/tty/serial/lantiq.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
index 044128277248..836ca51460f2 100644
--- a/drivers/tty/serial/lantiq.c
+++ b/drivers/tty/serial/lantiq.c
@@ -6,6 +6,7 @@
  * Copyright (C) 2007 Felix Fietkau <nbd@xxxxxxxxxxx>
  * Copyright (C) 2007 John Crispin <john@xxxxxxxxxxx>
  * Copyright (C) 2010 Thomas Langer, <thomas.langer@xxxxxxxxxx>
+ * Copyright (C) 2018 Intel Corporation.
  */
 
 #include <linux/slab.h>
@@ -688,7 +689,7 @@ lqasc_probe(struct platform_device *pdev)
 	struct ltq_uart_port *ltq_port;
 	struct uart_port *port;
 	struct resource *mmres, irqres[3];
-	int line = 0;
+	int line;
 	int ret;
 
 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -699,9 +700,19 @@ lqasc_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	/* check if this is the console port */
-	if (mmres->start != CPHYSADDR(LTQ_EARLY_ASC))
-		line = 1;
+	/* get serial id */
+	line = of_alias_get_id(node, "serial");
+	if (line < 0) {
+#ifdef CONFIG_LANTIQ
+		if (mmres->start == CPHYSADDR(LTQ_EARLY_ASC))
+			line = 0;
+		else
+			line = 1;
+#else
+		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", line);
+		return line;
+#endif
+	}
 
 	if (lqasc_port[line]) {
 		dev_err(&pdev->dev, "port %d already allocated\n", line);
-- 
2.11.0