Reworked airspeed driver to keep most of it abstract

3 files changed, 585 insertions, 0 deletions

diff --git a/src/drivers/airspeed/airspeed.cpp b/src/drivers/airspeed/airspeed.cpp
new file mode 100644
index 000000000..2c719928a
--- /dev/null
+++ b/src/drivers/airspeed/airspeed.cpp
@@ -0,0 +1,378 @@
+/****************************************************************************
+ *
+ *   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 ets_airspeed.cpp
+ * @author Simon Wilks
+ *
+ * Driver for the Eagle Tree Airspeed V3 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>
+
+#include <drivers/airspeed/airspeed.h>
+
+Airspeed::Airspeed(int bus, int address, unsigned conversion_interval) :
+	I2C("Airspeed", AIRSPEED_DEVICE_PATH, bus, address, 100000),
+	_num_reports(0),
+	_next_report(0),
+	_oldest_report(0),
+	_reports(nullptr),
+	_sensor_ok(false),
+	_measure_ticks(0),
+	_collect_phase(false),
+	_diff_pres_offset(0.0f),
+	_airspeed_pub(-1),
+	_conversion_interval(conversion_interval),
+	_sample_perf(perf_alloc(PC_ELAPSED, "airspeed_read")),
+	_comms_errors(perf_alloc(PC_COUNT, "airspeed_comms_errors")),
+	_buffer_overflows(perf_alloc(PC_COUNT, "airspeed_buffer_overflows"))
+{
+	// enable debug() calls
+	_debug_enabled = true;
+
+	// work_cancel in the dtor will explode if we don't do this...
+	memset(&_work, 0, sizeof(_work));
+}
+
+Airspeed::~Airspeed()
+{
+	/* make sure we are truly inactive */
+	stop();
+
+	/* free any existing reports */
+	if (_reports != nullptr)
+		delete[] _reports;
+}
+
+int
+Airspeed::init()
+{
+	int ret = ERROR;
+
+	/* do I2C init (and probe) first */
+	if (I2C::init() != OK)
+		goto out;
+
+	/* allocate basic report buffers */
+	_num_reports = 2;
+	_reports = new struct differential_pressure_s[_num_reports];
+
+	for (unsigned i = 0; i < _num_reports; i++)
+		_reports[i].max_differential_pressure_pa = 0;
+
+	if (_reports == nullptr)
+		goto out;
+
+	_oldest_report = _next_report = 0;
+
+	/* get a publish handle on the airspeed topic */
+	memset(&_reports[0], 0, sizeof(_reports[0]));
+	_airspeed_pub = orb_advertise(ORB_ID(differential_pressure), &_reports[0]);
+
+	if (_airspeed_pub < 0)
+		debug("failed to create airspeed sensor object. Did you start uOrb?");
+
+	ret = OK;
+	/* sensor is ok, but we don't really know if it is within range */
+	_sensor_ok = true;
+out:
+	return ret;
+}
+
+int
+Airspeed::probe()
+{
+	return measure();
+}
+
+int
+Airspeed::ioctl(struct file *filp, int cmd, unsigned long arg)
+{
+	switch (cmd) {
+
+	case SENSORIOCSPOLLRATE: {
+			switch (arg) {
+
+				/* switching to manual polling */
+			case SENSOR_POLLRATE_MANUAL:
+				stop();
+				_measure_ticks = 0;
+				return OK;
+
+				/* external signalling (DRDY) not supported */
+			case SENSOR_POLLRATE_EXTERNAL:
+
+				/* zero would be bad */
+			case 0:
+				return -EINVAL;
+
+				/* set default/max polling rate */
+			case SENSOR_POLLRATE_MAX:
+			case SENSOR_POLLRATE_DEFAULT: {
+					/* do we need to start internal polling? */
+					bool want_start = (_measure_ticks == 0);
+
+					/* set interval for next measurement to minimum legal value */
+					_measure_ticks = USEC2TICK(_conversion_interval);
+
+					/* if we need to start the poll state machine, do it */
+					if (want_start)
+						start();
+
+					return OK;
+				}
+
+				/* adjust to a legal polling interval in Hz */
+			default: {
+					/* do we need to start internal polling? */
+					bool want_start = (_measure_ticks == 0);
+
+					/* convert hz to tick interval via microseconds */
+					unsigned ticks = USEC2TICK(1000000 / arg);
+
+					/* check against maximum rate */
+					if (ticks < USEC2TICK(_conversion_interval))
+						return -EINVAL;
+
+					/* update interval for next measurement */
+					_measure_ticks = ticks;
+
+					/* if we need to start the poll state machine, do it */
+					if (want_start)
+						start();
+
+					return OK;
+				}
+			}
+		}
+
+	case SENSORIOCGPOLLRATE:
+		if (_measure_ticks == 0)
+			return SENSOR_POLLRATE_MANUAL;
+
+		return (1000 / _measure_ticks);
+
+	case SENSORIOCSQUEUEDEPTH: {
+			/* add one to account for the sentinel in the ring */
+			arg++;
+
+			/* lower bound is mandatory, upper bound is a sanity check */
+			if ((arg < 2) || (arg > 100))
+				return -EINVAL;
+
+			/* allocate new buffer */
+			struct differential_pressure_s *buf = new struct differential_pressure_s[arg];
+
+			if (nullptr == buf)
+				return -ENOMEM;
+
+			/* reset the measurement state machine with the new buffer, free the old */
+			stop();
+			delete[] _reports;
+			_num_reports = arg;
+			_reports = buf;
+			start();
+
+			return OK;
+		}
+
+	case SENSORIOCGQUEUEDEPTH:
+		return _num_reports - 1;
+
+	case SENSORIOCRESET:
+		/* XXX implement this */
+		return -EINVAL;
+
+	case AIRSPEEDIOCSSCALE: {
+		struct airspeed_scale *s = (struct airspeed_scale*)arg;
+		_diff_pres_offset = s->offset_pa;
+		return OK;
+		}
+
+	case AIRSPEEDIOCGSCALE: {
+		struct airspeed_scale *s = (struct airspeed_scale*)arg;
+		s->offset_pa = _diff_pres_offset;
+		s->scale = 1.0f;
+		return OK;
+		}
+
+	default:
+		/* give it to the superclass */
+		return I2C::ioctl(filp, cmd, arg);
+	}
+}
+
+ssize_t
+Airspeed::read(struct file *filp, char *buffer, size_t buflen)
+{
+	unsigned count = buflen / sizeof(struct differential_pressure_s);
+	int ret = 0;
+
+	/* buffer must be large enough */
+	if (count < 1)
+		return -ENOSPC;
+
+	/* if automatic measurement is enabled */
+	if (_measure_ticks > 0) {
+
+		/*
+		 * While there is space in the caller's buffer, and reports, copy them.
+		 * Note that we may be pre-empted by the workq thread while we are doing this;
+		 * we are careful to avoid racing with them.
+		 */
+		while (count--) {
+			if (_oldest_report != _next_report) {
+				memcpy(buffer, _reports + _oldest_report, sizeof(*_reports));
+				ret += sizeof(_reports[0]);
+				INCREMENT(_oldest_report, _num_reports);
+			}
+		}
+
+		/* if there was no data, warn the caller */
+		return ret ? ret : -EAGAIN;
+	}
+
+	/* manual measurement - run one conversion */
+	/* XXX really it'd be nice to lock against other readers here */
+	do {
+		_oldest_report = _next_report = 0;
+
+		/* trigger a measurement */
+		if (OK != measure()) {
+			ret = -EIO;
+			break;
+		}
+
+		/* wait for it to complete */
+		usleep(_conversion_interval);
+
+		/* run the collection phase */
+		if (OK != collect()) {
+			ret = -EIO;
+			break;
+		}
+
+		/* state machine will have generated a report, copy it out */
+		memcpy(buffer, _reports, sizeof(*_reports));
+		ret = sizeof(*_reports);
+
+	} while (0);
+
+	return ret;
+}
+
+void
+Airspeed::start()
+{
+	/* reset the report ring and state machine */
+	_collect_phase = false;
+	_oldest_report = _next_report = 0;
+
+	/* schedule a cycle to start things */
+	work_queue(HPWORK, &_work, (worker_t)&Airspeed::cycle_trampoline, this, 1);
+
+	/* notify about state change */
+	struct subsystem_info_s info = {
+		true,
+		true,
+		true,
+		SUBSYSTEM_TYPE_DIFFPRESSURE
+	};
+	static orb_advert_t pub = -1;
+
+	if (pub > 0) {
+		orb_publish(ORB_ID(subsystem_info), pub, &info);
+
+	} else {
+		pub = orb_advertise(ORB_ID(subsystem_info), &info);
+	}
+}
+
+void
+Airspeed::stop()
+{
+	work_cancel(HPWORK, &_work);
+}
+
+void
+Airspeed::cycle_trampoline(void *arg)
+{
+	Airspeed *dev = (Airspeed *)arg;
+
+	dev->cycle();
+}
+
+void
+Airspeed::print_info()
+{
+	perf_print_counter(_sample_perf);
+	perf_print_counter(_comms_errors);
+	perf_print_counter(_buffer_overflows);
+	warnx("poll interval:  %u ticks", _measure_ticks);
+	warnx("report queue:   %u (%u/%u @ %p)",
+	       _num_reports, _oldest_report, _next_report, _reports);
+}
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)
+
diff --git a/src/drivers/airspeed/module.mk b/src/drivers/airspeed/module.mk
new file mode 100644
index 000000000..4eef06161
--- /dev/null
+++ b/src/drivers/airspeed/module.mk
@@ -0,0 +1,38 @@
+############################################################################
+#
+#   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.
+#
+############################################################################
+
+#
+# Makefile to build the generic airspeed driver.
+#
+
+SRCS			= airspeed.cpp