From f42c9579d751f948656f982402711df3c6b52285 Mon Sep 17 00:00:00 2001
From: Randy Mackay <rmackay9@yahoo.com>
Date: Mon, 7 Jul 2014 21:30:23 +0900
Subject: [PATCH] Compass: add dev_id for PX4

dev_id is retrieved from PX4Firmware via ioctl call
---
 libraries/AP_Compass/AP_Compass_PX4.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libraries/AP_Compass/AP_Compass_PX4.cpp b/libraries/AP_Compass/AP_Compass_PX4.cpp
index 9696cd57fe..f4673cc4fb 100644
--- a/libraries/AP_Compass/AP_Compass_PX4.cpp
+++ b/libraries/AP_Compass/AP_Compass_PX4.cpp
@@ -30,6 +30,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 
+#include <drivers/drv_device.h>
 #include <drivers/drv_mag.h>
 #include <drivers/drv_hrt.h>
 #include <stdio.h>
@@ -58,6 +59,9 @@ bool AP_Compass_PX4::init(void)
 	}
 
     for (uint8_t i=0; i<_num_instances; i++) {
+        // get device id
+        _dev_id[i] = ioctl(_mag_fd[i], DEVIOCGDEVICEID, 0);
+
         // average over up to 20 samples
         if (ioctl(_mag_fd[i], SENSORIOCSQUEUEDEPTH, 20) != 0) {
             hal.console->printf("Failed to setup compass queue\n");