From 0b7e14c69bedea234afc30902d1cb371b7e3274e Mon Sep 17 00:00:00 2001
From: Aaron Lindsay <aaron@aclindsay.com>
Date: Sun, 7 Oct 2012 10:28:33 -0400
Subject: [PATCH] serial: Allow more than one serial device to be registered

---
 drivers/serial.c         | 15 ++++++++++-----
 include/drivers/serial.h |  3 +++
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/serial.c b/drivers/serial.c
index 4431912..5b66ccd 100644
--- a/drivers/serial.c
+++ b/drivers/serial.c
@@ -21,16 +21,21 @@
 #include <init.h>
 #include <drivers/serial.h>
 
-struct serial_dev *first_serial_dev;
+struct dlist_node serial_dev_list;
 
 int serial_register_device(struct serial_dev *sdev) {
-	if (!first_serial_dev)
-		first_serial_dev = sdev;
+	if (!sdev)
+		return -1;
+
+	insert_before(&serial_dev_list, &sdev->list);
 	return 0;
 }
 
 struct serial_dev *serial_first_device() {
-	return first_serial_dev;
+	if (list_empty(&serial_dev_list))
+		return 0;
+
+	return container(serial_dev_list.next, struct serial_dev, list);
 }
 
 /*
@@ -40,5 +45,5 @@ struct serial_dev *serial_first_device() {
  * initialized in earlyinitcalls.
  */
 void serial_init() {
-	first_serial_dev = 0;
+	init_list(&serial_dev_list);
 }
diff --git a/include/drivers/serial.h b/include/drivers/serial.h
index 555a17a..80da521 100644
--- a/include/drivers/serial.h
+++ b/include/drivers/serial.h
@@ -18,9 +18,12 @@
     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include <list.h>
+
 struct serial_dev {
 	//TODO add more functions and attributes here
 	int (*putc)(char);
+	struct dlist_node list;
 };
 
 int serial_register_device(struct serial_dev *sdev);