1 files changed, 334 insertions, 0 deletions
diff --git a/src/modules/systemlib/mixer/mixer_simple.cpp b/src/modules/systemlib/mixer/mixer_simple.cpp
new file mode 100644
index 000000000..07dc5f37f
--- /dev/null
+++ b/src/modules/systemlib/mixer/mixer_simple.cpp
@@ -0,0 +1,334 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 mixer_simple.cpp
+ *
+ * Simple summing mixer.
+ */
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <errno.h>
+#include <stdio.h>
+#include <math.h>
+#include <unistd.h>
+#include <ctype.h>
+
+#include "mixer.h"
+
+#define debug(fmt, args...)	do { } while(0)
+//#define debug(fmt, args...)	do { printf("[mixer] " fmt "\n", ##args); } while(0)
+
+SimpleMixer::SimpleMixer(ControlCallback control_cb,
+			 uintptr_t cb_handle,
+			 mixer_simple_s *mixinfo) :
+	Mixer(control_cb, cb_handle),
+	_info(mixinfo)
+{
+}
+
+SimpleMixer::~SimpleMixer()
+{
+	if (_info != nullptr)
+		free(_info);
+}
+
+static const char *
+findtag(const char *buf, unsigned &buflen, char tag)
+{
+	while (buflen >= 2) {
+		if ((buf[0] == tag) && (buf[1] == ':'))
+			return buf;
+		buf++;
+		buflen--;
+	}
+	return nullptr;
+}
+
+static void
+skipline(const char *buf, unsigned &buflen)
+{
+	const char *p;
+
+	/* if we can find a CR or NL in the buffer, skip up to it */
+	if ((p = (const char *)memchr(buf, '\r', buflen)) || (p = (const char *)memchr(buf, '\n', buflen)))
+		buflen -= (p - buf);
+}
+
+int
+SimpleMixer::parse_output_scaler(const char *buf, unsigned &buflen, mixer_scaler_s &scaler)
+{
+	int ret;
+	int s[5];
+	
+	buf = findtag(buf, buflen, 'O');
+	if ((buf == nullptr) || (buflen < 12))
+		return -1;
+
+	if ((ret = sscanf(buf, "O: %d %d %d %d %d",
+			  &s[0], &s[1], &s[2], &s[3], &s[4])) != 5) {
+		debug("scaler parse failed on '%s' (got %d)", buf, ret);
+		return -1;
+	}
+	skipline(buf, buflen);
+
+	scaler.negative_scale	= s[0] / 10000.0f;
+	scaler.positive_scale	= s[1] / 10000.0f;
+	scaler.offset		= s[2] / 10000.0f;
+	scaler.min_output	= s[3] / 10000.0f;
+	scaler.max_output	= s[4] / 10000.0f;
+
+	return 0;
+}
+
+int
+SimpleMixer::parse_control_scaler(const char *buf, unsigned &buflen, mixer_scaler_s &scaler, uint8_t &control_group, uint8_t &control_index)
+{
+	unsigned u[2];
+	int s[5];
+
+	buf = findtag(buf, buflen, 'S');
+	if ((buf == nullptr) || (buflen < 16))
+		return -1;
+
+	if (sscanf(buf, "S: %u %u %d %d %d %d %d",
+		   &u[0], &u[1], &s[0], &s[1], &s[2], &s[3], &s[4]) != 7) {
+		debug("control parse failed on '%s'", buf);
+		return -1;
+	}
+	skipline(buf, buflen);
+
+	control_group		= u[0];
+	control_index		= u[1];
+	scaler.negative_scale	= s[0] / 10000.0f;
+	scaler.positive_scale	= s[1] / 10000.0f;
+	scaler.offset		= s[2] / 10000.0f;
+	scaler.min_output	= s[3] / 10000.0f;
+	scaler.max_output	= s[4] / 10000.0f;
+
+	return 0;
+}
+
+SimpleMixer *
+SimpleMixer::from_text(Mixer::ControlCallback control_cb, uintptr_t cb_handle, const char *buf, unsigned &buflen)
+{
+	SimpleMixer *sm = nullptr;
+	mixer_simple_s *mixinfo = nullptr;
+	unsigned inputs;
+	int used;
+	const char *end = buf + buflen;
+
+	/* get the base info for the mixer */
+	if (sscanf(buf, "M: %u%n", &inputs, &used) != 1) {
+		debug("simple parse failed on '%s'", buf);
+		goto out;
+	}
+
+	buflen -= used;
+
+	mixinfo = (mixer_simple_s *)malloc(MIXER_SIMPLE_SIZE(inputs));
+
+	if (mixinfo == nullptr) {
+		debug("could not allocate memory for mixer info");
+		goto out;
+	}
+
+	mixinfo->control_count = inputs;
+
+	if (parse_output_scaler(end - buflen, buflen, mixinfo->output_scaler))
+		goto out;
+
+	for (unsigned i = 0; i < inputs; i++) {
+		if (parse_control_scaler(end - buflen, buflen,
+					 mixinfo->controls[i].scaler,
+					 mixinfo->controls[i].control_group,
+					 mixinfo->controls[i].control_index))
+			goto out;
+	}
+
+	sm = new SimpleMixer(control_cb, cb_handle, mixinfo);
+
+	if (sm != nullptr) {
+		mixinfo = nullptr;
+		debug("loaded mixer with %d inputs", inputs);
+
+	} else {
+		debug("could not allocate memory for mixer");
+	}
+
+out:
+
+	if (mixinfo != nullptr)
+		free(mixinfo);
+
+	return sm;
+}
+
+SimpleMixer *
+SimpleMixer::pwm_input(Mixer::ControlCallback control_cb, uintptr_t cb_handle, unsigned input, uint16_t min, uint16_t mid, uint16_t max)
+{
+	SimpleMixer *sm = nullptr;
+	mixer_simple_s *mixinfo = nullptr;
+
+	mixinfo = (mixer_simple_s *)malloc(MIXER_SIMPLE_SIZE(1));
+
+	if (mixinfo == nullptr) {
+		debug("could not allocate memory for mixer info");
+		goto out;
+	}
+
+	mixinfo->control_count = 1;
+
+	/*
+	 * Always pull from group 0, with the input value giving the channel.
+	 */
+	mixinfo->controls[0].control_group = 0;
+	mixinfo->controls[0].control_index = input;
+
+	/*
+	 * Conversion uses both the input and output side of the mixer.
+	 *
+	 * The input side is used to slide the control value such that the min argument
+	 * results in a value of zero.
+	 *
+	 * The output side is used to apply the scaling for the min/max values so that
+	 * the resulting output is a -1.0 ... 1.0 value for the min...max range.
+	 */
+	mixinfo->controls[0].scaler.negative_scale = 1.0f;
+	mixinfo->controls[0].scaler.positive_scale = 1.0f;
+	mixinfo->controls[0].scaler.offset = -mid;
+	mixinfo->controls[0].scaler.min_output = -(mid - min);
+	mixinfo->controls[0].scaler.max_output = (max - mid);
+
+	mixinfo->output_scaler.negative_scale = 500.0f / (mid - min);
+	mixinfo->output_scaler.positive_scale = 500.0f / (max - mid);
+	mixinfo->output_scaler.offset = 0.0f;
+	mixinfo->output_scaler.min_output = -1.0f;
+	mixinfo->output_scaler.max_output = 1.0f;
+
+	sm = new SimpleMixer(control_cb, cb_handle, mixinfo);
+
+	if (sm != nullptr) {
+		mixinfo = nullptr;
+		debug("PWM input mixer for %d", input);
+
+	} else {
+		debug("could not allocate memory for PWM input mixer");
+	}
+
+out:
+
+	if (mixinfo != nullptr)
+		free(mixinfo);
+
+	return sm;
+}
+
+unsigned
+SimpleMixer::mix(float *outputs, unsigned space)
+{
+	float		sum = 0.0f;
+
+	if (_info == nullptr)
+		return 0;
+
+	if (space < 1)
+		return 0;
+
+	for (unsigned i = 0; i < _info->control_count; i++) {
+		float input;
+
+		_control_cb(_cb_handle,
+			    _info->controls[i].control_group,
+			    _info->controls[i].control_index,
+			    input);
+
+		sum += scale(_info->controls[i].scaler, input);
+	}
+
+	*outputs = scale(_info->output_scaler, sum);
+	return 1;
+}
+
+void
+SimpleMixer::groups_required(uint32_t &groups)
+{
+	for (unsigned i = 0; i < _info->control_count; i++)
+		groups |= 1 << _info->controls[i].control_group;
+}
+
+int
+SimpleMixer::check()
+{
+	int ret;
+	float junk;
+
+	/* sanity that presumes that a mixer includes a control no more than once */
+	/* max of 32 groups due to groups_required API */
+	if (_info->control_count > 32)
+		return -2;
+
+	/* validate the output scaler */
+	ret = scale_check(_info->output_scaler);
+
+	if (ret != 0)
+		return ret;
+
+	/* validate input scalers */
+	for (unsigned i = 0; i < _info->control_count; i++) {
+
+		/* verify that we can fetch the control */
+		if (_control_cb(_cb_handle,
+				_info->controls[i].control_group,
+				_info->controls[i].control_index,
+				junk) != 0) {
+			return -3;
+		}
+
+		/* validate the scaler */
+		ret = scale_check(_info->controls[i].scaler);
+
+		if (ret != 0)
+			return (10 * i + ret);
+	}
+
+	return 0;
+}