px4-firmware/apps/drivers/drv_pwm_output.h

113 lines
3.6 KiB
C

/****************************************************************************
*
* 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 PWM servo output interface.
*
* Servo values can be set with the PWM_SERVO_SET ioctl, by writing a
* pwm_output_values structure to the device, or by publishing to the
* output_pwm ObjDev.
* Writing a value of 0 to a channel suppresses any output for that
* channel.
*/
#ifndef _DRV_PWM_OUTPUT_H
#define _DRV_PWM_OUTPUT_H
#include <stdint.h>
#include <sys/ioctl.h>
#include "drv_orb_dev.h"
/**
* Path for the default PWM output device.
*
* Note that on systems with more than one PWM output path (e.g.
* PX4FMU with PX4IO connected) there may be other devices that
* respond to this protocol.
*/
#define PWM_OUTPUT_DEVICE_PATH "/dev/pwm_output"
/**
* Maximum number of PWM output channels in the system.
*/
#define PWM_OUTPUT_MAX_CHANNELS 16
/**
* Servo output signal type, value is actual servo output pulse
* width in microseconds.
*/
typedef uint16_t servo_position_t;
/**
* Servo output status structure.
*
* May be published to output_pwm, or written to a PWM output
* device.
*/
struct pwm_output_values {
/** desired servo update rate in Hz */
uint32_t update_rate;
/** desired pulse widths for each of the supported channels */
servo_position_t values[PWM_OUTPUT_MAX_CHANNELS];
};
/*
* ObjDev tag for PWM outputs.
*/
ORB_DECLARE(output_pwm);
/*
* ioctl() definitions
*
* Note that ioctls and ObjDev updates should not be mixed, as the
* behaviour of the system in this case is not defined.
*/
#define _PWM_SERVO_BASE 0x2600
/** arm all servo outputs handle by this driver */
#define PWM_SERVO_ARM _IOC(_PWM_SERVO_BASE, 0)
/** disarm all servo outputs (stop generating pulses) */
#define PWM_SERVO_DISARM _IOC(_PWM_SERVO_BASE, 1)
/** set a single servo to a specific value */
#define PWM_SERVO_SET(_servo) _IOC(_PWM_SERVO_BASE, 0x20 + _servo)
/** get a single specific servo value */
#define PWM_SERVO_GET(_servo) _IOC(_PWM_SERVO_BASE, 0x40 + _servo)
#endif /* _DRV_PWM_OUTPUT_H */