From 9356b0cb1ef896c485e0855cddb22bb66d83c567 Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Wed, 2 Jan 2013 15:15:01 -0800
Subject: [PATCH] Changed Linux serial port enumeration to leverage kernel
 provided device information in /sys/class/tty

---
 sim_serial.c | 57 +++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 45 insertions(+), 12 deletions(-)

diff --git a/sim_serial.c b/sim_serial.c
index ff9ba2b9..b8df7ab0 100644
--- a/sim_serial.c
+++ b/sim_serial.c
@@ -866,9 +866,10 @@ return;
 /* Enumerate the available serial ports.
 
    The serial port names generated by attempting to open /dev/ttyS0 thru
-   /dev/ttyS53 and /dev/ttyUSB0 thru /dev/ttyUSB0.  Ones we can open and
-   are ttys (as determined by isatty()) are added to the list.  The list 
-   is sorted alphabetically by device name.
+   /dev/ttyS63 and /dev/ttyUSB0 thru /dev/ttyUSB63 and /dev/tty.serial0
+   thru /dev/tty.serial63.  Ones we can open and are ttys (as determined 
+   by isatty()) are added to the list.  The list is sorted alphabetically 
+   by device name.
 
 */
 
@@ -879,6 +880,46 @@ int port;
 int ports = 0;
 
 memset(list, 0, max*sizeof(*list));
+#if defined(__linux__)
+#include <dirent.h>
+#include <libgen.h>
+#include <unistd.h>
+#include <sys/stat.h>
+if (1) {
+    struct dirent **namelist;
+    int n;
+    struct stat st;
+
+    n = scandir("/sys/class/tty/", &namelist, NULL, NULL);
+
+    while (n--) {
+        if (strcmp(namelist[n]->d_name, ".") &&
+            strcmp(namelist[n]->d_name, "..")) {
+            char path[1024], devicepath[1024], driverpath[1024];
+
+            sprintf (path, "/sys/class/tty/%s", namelist[n]->d_name);
+            sprintf (devicepath, "/sys/class/tty/%s/device", namelist[n]->d_name);
+            sprintf (driverpath, "/sys/class/tty/%s/device/driver", namelist[n]->d_name);
+            if ((lstat(devicepath, &st) == 0) && S_ISLNK(st.st_mode)) {
+                char buffer[1024];
+
+                memset (buffer, 0, sizeof(buffer));
+                if (readlink(driverpath, buffer, sizeof(buffer)) > 0) {
+                    sprintf (list[ports].name, "/dev/%s", basename (path));
+                    port = open (list[ports].name, O_RDWR | O_NOCTTY | O_NONBLOCK);     /* open the port */
+                    if (port != -1) {                   /* open OK? */
+                        if (isatty (port))              /* is device a TTY? */
+                            ++ports;
+                        close (port);
+                        }
+                    }
+                }
+            }
+        free (namelist[n]);
+        }
+    free (namelist);
+    }
+#else /* Non Linux, just try some well known device names */
 for (i=0; (ports < max) && (i < 64); ++i) {
     sprintf (list[ports].name, "/dev/ttyS%d", i);
     port = open (list[ports].name, O_RDWR | O_NOCTTY | O_NONBLOCK);     /* open the port */
@@ -897,15 +938,6 @@ for (i=0; (ports < max) && (i < 64); ++i) {
         close (port);
         }
     }
-for (i=0; (ports < max) && (i < 64); ++i) {
-    sprintf (list[ports].name, "/dev/ttyAMA%d", i);
-    port = open (list[ports].name, O_RDWR | O_NOCTTY | O_NONBLOCK);     /* open the port */
-    if (port != -1) {                                   /* open OK? */
-        if (isatty (port))                              /* is device a TTY? */
-            ++ports;
-        close (port);
-        }
-    }
 for (i=1; (ports < max) && (i < 64); ++i) {
     sprintf (list[ports].name, "/dev/tty.serial%d", i);
     port = open (list[ports].name, O_RDWR | O_NOCTTY | O_NONBLOCK);     /* open the port */
@@ -915,6 +947,7 @@ for (i=1; (ports < max) && (i < 64); ++i) {
         close (port);
         }
     }
+#endif
 return ports;
 }