From 10171df59a016418279569a15ca0e1ae3e2b0bc7 Mon Sep 17 00:00:00 2001
From: tumbili <bapstr@ethz.ch>
Date: Wed, 9 Sep 2015 22:57:21 +0200
Subject: [PATCH] ll40ls: do not start driver if already started

---
 src/drivers/ll40ls/ll40ls.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/drivers/ll40ls/ll40ls.cpp b/src/drivers/ll40ls/ll40ls.cpp
index 71f4134790..a4c8720dbc 100644
--- a/src/drivers/ll40ls/ll40ls.cpp
+++ b/src/drivers/ll40ls/ll40ls.cpp
@@ -113,6 +113,10 @@ LidarLite * get_dev(const bool use_i2c, const int bus) {
  */
 void start(const bool use_i2c, const int bus)
 {
+	if (g_dev_int != nullptr || g_dev_ext != nullptr || g_dev_pwm != nullptr) {
+		errx(1,"driver already started");
+	}
+
 	if (use_i2c) {
 		/* create the driver, attempt expansion bus first */
 		if (bus == -1 || bus == PX4_I2C_BUS_EXPANSION) {
@@ -464,7 +468,6 @@ ll40ls_main(int argc, char *argv[])
 
 		/* Start/load the driver. */
 		if (!strcmp(verb, "start")) {
-
 			ll40ls::start(use_i2c, bus);
 		}