Add DS support.

Change-Id: Ib8bc4e171dd5ca526f8e151ff3d467097582a8cb
diff --git a/mbtk/mbtk_utils/at.c b/mbtk/mbtk_utils/at.c
index 1e8f91b..a776aba 100755
--- a/mbtk/mbtk_utils/at.c
+++ b/mbtk/mbtk_utils/at.c
@@ -477,6 +477,7 @@
 
     char *at_cmd = NULL;
     bool echo = FALSE;
+    char *dev = NULL;
     if(argc == 1) {
         at_mode = AT_MODE_SOCK_1;
     } else if(argc == 2) {
@@ -485,6 +486,9 @@
             at_cmd = argv[1];
         } else if(!strncasecmp(argv[1], "/dev/", 5)) {
             at_mode = AT_MODE_DEV_1;
+        } else if(!strncasecmp(argv[1], "/tmp/", 5)) {
+            at_mode = AT_MODE_SOCK_1;
+            dev = argv[1];
         } else {
             help();
             return -1;
@@ -522,7 +526,11 @@
 #endif
 
     if(at_mode == AT_MODE_SOCK_1 || at_mode == AT_MODE_SOCK_2) {
-        at_fd = openSocket("/tmp/atcmdmbtk");
+        if(dev == NULL) {
+            at_fd = openSocket("/tmp/atcmdmbtk");
+        } else {
+            at_fd = openSocket(dev);
+        }
     } else {
 #if 0
         at_fd = at_open(argv[1]);