Reworked airspeed driver to keep most of it abstract

1 files changed, 169 insertions, 0 deletions

diff --git a/src/drivers/airspeed/airspeed.h b/src/drivers/airspeed/airspeed.h
new file mode 100644
index 000000000..3cc03ede9
--- /dev/null
+++ b/src/drivers/airspeed/airspeed.h
@@ -0,0 +1,169 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2013 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 airspeed.h
+ * @author Simon Wilks
+ *
+ * Generic driver for airspeed sensors connected via I2C.
+ */
+
+#include <nuttx/config.h>
+
+#include <drivers/device/i2c.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <semaphore.h>
+#include <string.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <errno.h>
+#include <stdio.h>
+#include <math.h>
+#include <unistd.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/wqueue.h>
+#include <nuttx/clock.h>
+
+#include <arch/board/board.h>
+
+#include <systemlib/airspeed.h>
+#include <systemlib/err.h>
+#include <systemlib/param/param.h>
+#include <systemlib/perf_counter.h>
+
+#include <drivers/drv_airspeed.h>
+#include <drivers/drv_hrt.h>
+
+#include <uORB/uORB.h>
+#include <uORB/topics/differential_pressure.h>
+#include <uORB/topics/subsystem_info.h>
+
+/* Default I2C bus */
+#define PX4_I2C_BUS_DEFAULT		PX4_I2C_BUS_EXPANSION
+
+/* Oddly, ERROR is not defined for C++ */
+#ifdef ERROR
+# undef ERROR
+#endif
+static const int ERROR = -1;
+
+#ifndef CONFIG_SCHED_WORKQUEUE
+# error This requires CONFIG_SCHED_WORKQUEUE.
+#endif
+
+class Airspeed : public device::I2C
+{
+public:
+	Airspeed(int bus, int address, unsigned conversion_interval);
+	virtual ~Airspeed();
+
+	virtual int	init();
+
+	virtual ssize_t	read(struct file *filp, char *buffer, size_t buflen);
+	virtual int	ioctl(struct file *filp, int cmd, unsigned long arg);
+
+	/**
+	 * Diagnostics - print some basic information about the driver.
+	 */
+	void		print_info();
+
+protected:
+	virtual int	probe();
+
+	/**
+	* Perform a poll cycle; collect from the previous measurement
+	* and start a new one.
+	*/
+	virtual void	cycle() = 0;
+	virtual int	measure() = 0;
+	virtual int	collect() = 0;
+
+	work_s			_work;
+	unsigned		_num_reports;
+	volatile unsigned	_next_report;
+	volatile unsigned	_oldest_report;
+	differential_pressure_s	*_reports;
+	bool			_sensor_ok;
+	int			_measure_ticks;
+	bool			_collect_phase;
+	float			_diff_pres_offset;
+
+	orb_advert_t		_airspeed_pub;
+
+	unsigned		_conversion_interval;
+
+	perf_counter_t		_sample_perf;
+	perf_counter_t		_comms_errors;
+	perf_counter_t		_buffer_overflows;
+
+
+	/**
+	* Test whether the device supported by the driver is present at a
+	* specific address.
+	*
+	* @param address	The I2C bus address to probe.
+	* @return		True if the device is present.
+	*/
+	int	probe_address(uint8_t address);
+
+	/**
+	* Initialise the automatic measurement state machine and start it.
+	*
+	* @note This function is called at open and error time.  It might make sense
+	*       to make it more aggressive about resetting the bus in case of errors.
+	*/
+	void	start();
+
+	/**
+	* Stop the automatic measurement state machine.
+	*/
+	void	stop();
+
+	/**
+	* Static trampoline from the workq context; because we don't have a
+	* generic workq wrapper yet.
+	*
+	* @param arg		Instance pointer for the driver that is polling.
+	*/
+	static void	cycle_trampoline(void *arg);
+
+};
+
+/* helper macro for handling report buffer indices */
+#define INCREMENT(_x, _lim)	do { _x++; if (_x >= _lim) _x = 0; } while(0)
+