New lightweight class to connect to the MPU9250

It needs to be determined if this class should be for any imu sensor or
if it is specific to the MPU9250.
Also, the callback doesn't publish anything just yet.

src/platforms/posix/drivers/df_imu/CMakeLists.txt

+############################################################################
+#
+#   Copyright (c) 2016 PX4 Development Team. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name PX4 nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+px4_add_module(
+	MODULE platforms__posix__drivers__df_imu
+	MAIN df_imu
+	SRCS
+		df_imu.cpp
+	DEPENDS
+		platforms__common
+		df_driver_framework
+	)
+# vim: set noet ft=cmake fenc=utf-8 ff=unix :

src/platforms/posix/drivers/df_imu/df_imu.cpp

+/****************************************************************************
+ *
+ * Copyright (c) 2016 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file df_imu.cpp
+ * Lightweight driver to access IMU driver of DriverFramework.
+ *
+ * @author Julian Oes <julian@oes.ch>
+ */
+
+#include <px4_config.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <unistd.h>
+#include <px4_getopt.h>
+#include <errno.h>
+
+#include <systemlib/perf_counter.h>
+#include <systemlib/err.h>
+
+#include <drivers/drv_accel.h>
+
+#include <board_config.h>
+//#include <mathlib/math/filter/LowPassFilter2p.hpp>
+//#include <lib/conversion/rotation.h>
+//
+//#include "DriverFramework.hpp"
+#include "lib/DriverFramework/drivers/imu/mpu9250/MPU9250.hpp"
+#include "DevMgr.hpp"
+
+
+extern "C" { __EXPORT int df_imu_main(int argc, char *argv[]); }
+
+using namespace DriverFramework;
+
+
+class DfImu : MPU9250
+{
+public:
+	DfImu(/*enum Rotation rotation*/);
+	~DfImu();
+
+	//enum Rotation		_rotation;
+
+	/**
+	 * Start automatic measurement.
+	 *
+	 * @return 0 on success
+	 */
+	int		start();
+
+	/**
+	 * Stop automatic measurement.
+	 *
+	 * @return 0 on success
+	 */
+	int		stop();
+
+private:
+	virtual int _publish_callback(struct imu_sensor_data &data);
+
+};
+
+DfImu::DfImu(/*enum Rotation rotation*/) :
+	MPU9250(IMU_DEVICE_PATH)
+	/*_rotation(rotation)*/
+{
+}
+
+DfImu::~DfImu()
+{
+}
+
+int DfImu::start()
+{
+	/* start sensor */
+	PX4_WARN("DF IMU STARTED==================================================");
+	int ret = MPU9250::init();
+
+	if (ret != 0) {
+		PX4_ERR("MPU9250 init fail: %d", ret);
+		return -1;
+	}
+
+	ret = MPU9250::start();
+
+	if (ret != 0) {
+		PX4_ERR("MPU9250 start fail: %d", ret);
+		return -1;
+	}
+
+
+	return 0;
+}
+
+int DfImu::stop()
+{
+	/* stop sensor */
+	PX4_WARN("DF IMU STOPPED==================================================");
+	return 0;
+}
+
+int DfImu::_publish_callback(struct imu_sensor_data &data) {
+	PX4_WARN("publish");
+	return 0;
+};
+
+
+namespace df_imu {
+
+DfImu *g_dev = nullptr;
+
+int start(/* enum Rotation rotation */);
+int stop();
+int info();
+void usage();
+
+int start(/*enum Rotation rotation*/)
+{
+	g_dev = new DfImu(/*rotation*/);
+	return g_dev->start();
+}
+
+int stop()
+{
+	if (g_dev == nullptr) {
+		PX4_ERR("driver not running");
+		return 1;
+	}
+
+	int ret = g_dev->stop();
+	if (ret != 0) {
+		PX4_ERR("driver could not be stopped");
+		return ret;
+	}
+
+	delete g_dev;
+	g_dev = nullptr;
+	return 0;
+}
+
+/**
+ * Print a little info about the driver.
+ */
+int
+info()
+{
+	if (g_dev == nullptr) {
+		PX4_ERR("driver not running");
+		return 1;
+	}
+
+	PX4_DEBUG("state @ %p", g_dev);
+
+	return 0;
+}
+
+void
+usage()
+{
+	PX4_WARN("Usage: df_imu 'start', 'info', 'stop'");
+	PX4_WARN("options:");
+	//PX4_WARN("    -R rotation");
+}
+
+} // namespace
+
+int
+df_imu_main(int argc, char *argv[])
+{
+	int ch;
+	// enum Rotation rotation = ROTATION_NONE;
+	int ret = 0;
+	int myoptind = 1;
+	const char *myoptarg = NULL;
+
+	/* jump over start/off/etc and look at options first */
+	while ((ch = px4_getopt(argc, argv, "R:", &myoptind, &myoptarg)) != EOF) {
+		switch (ch) {
+		//case 'R':
+		//	rotation = (enum Rotation)atoi(myoptarg);
+		//	break;
+
+		default:
+			df_imu::usage();
+			return 0;
+		}
+	}
+
+	if (argc <= 1) {
+		df_imu::usage();
+		return 1;
+	}
+
+	const char *verb = argv[myoptind];
+
+
+	if (!strcmp(verb, "start")) {
+		ret = df_imu::start(/*rotation*/);
+	}
+
+	else if (!strcmp(verb, "stop")) {
+		ret = df_imu::stop();
+	}
+
+	else if (!strcmp(verb, "info")) {
+		ret = df_imu::info();
+	}
+
+	else {
+		df_imu::usage();
+		return 1;
+	}
+
+	return ret;
+}