/****************************************************************************
*
* 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
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*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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****************************************************************************/
/**
* @file drv_mixer.h
*
* Mixer ioctl interfaces.
*
* Normal workflow is:
*
* - open mixer device
* - add mixer(s)
* loop:
* - mix actuators to array
*
* Each client has its own configuration.
*
* When mixing, outputs are produced by mixers in the order they are
* added. A simple mixer produces one output; a multotor mixer will
* produce several outputs, etc.
*/
#ifndef _DRV_MIXER_H
#define _DRV_MIXER_H
#include <stdint.h>
#include <sys/ioctl.h>
#define MIXER_DEVICE_PATH "/dev/mixer"
/*
* ioctl() definitions
*/
#define _MIXERIOCBASE (0x2500)
#define _MIXERIOC(_n) (_IOC(_MIXERIOCBASE, _n))
/** get the number of mixable outputs */
#define MIXERIOCGETOUTPUTCOUNT _MIXERIOC(0)
/** reset (clear) the mixer configuration */
#define MIXERIOCRESET _MIXERIOC(1)
/** simple channel scaler */
struct mixer_scaler_s {
float negative_scale;
float positive_scale;
float offset;
float min_output;
float max_output;
};
/** mixer input */
struct mixer_control_s {
uint8_t control_group; /**< group from which the input reads */
uint8_t control_index; /**< index within the control group */
struct mixer_scaler_s scaler; /**< scaling applied to the input before use */
};
/** simple mixer */
struct mixer_simple_s {
uint8_t control_count; /**< number of inputs */
struct mixer_scaler_s output_scaler; /**< scaling for the output */
struct mixer_control_s controls[0]; /**< actual size of the array is set by control_count */
};
#define MIXER_SIMPLE_SIZE(_icount) (sizeof(struct mixer_simple_s) + (_icount) * sizeof(struct mixer_control_s))
/**
* add a simple mixer in (struct mixer_simple_s *)arg
*/
#define MIXERIOCADDSIMPLE _MIXERIOC(2)
/* _MIXERIOC(3) was deprecated */
/* _MIXERIOC(4) was deprecated */
/**
* Add mixer(s) from the buffer in (const char *)arg
*/
#define MIXERIOCLOADBUF _MIXERIOC(5)
/*
* XXX Thoughts for additional operations:
*
* - get/set output scale, for tuning center/limit values.
* - save/serialise for saving tuned mixers.
*/
#endif /* _DRV_ACCEL_H */
