/****************************************************************************
 *
 *   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
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 ****************************************************************************/

/**
 * @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 ORB topic.
 * Writing a value of 0 to a channel suppresses any output for that
 * channel.
 */

#pragma once

#include <stdint.h>
#include <sys/ioctl.h>

#include "drv_orb_dev.h"

__BEGIN_DECLS

/**
 * 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 supported by the device.
 */
#define PWM_OUTPUT_MAX_CHANNELS	16

/**
 * Lowest minimum PWM in us
 */
#define PWM_LOWEST_MIN 900

/**
 * Default minimum PWM in us
 */
#define PWM_DEFAULT_MIN 1000

/**
 * Highest PWM allowed as the minimum PWM
 */
#define PWM_HIGHEST_MIN 1300

/**
 * Highest maximum PWM in us
 */
#define PWM_HIGHEST_MAX 2100

/**
 * Default maximum PWM in us
 */
#define PWM_DEFAULT_MAX 2000

/**
 * Lowest PWM allowed as the maximum PWM
 */
#define PWM_LOWEST_MAX 1700

/**
 * Do not output a channel with this value
 */
#define PWM_IGNORE_THIS_CHANNEL UINT16_MAX

/**
 * 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 pulse widths for each of the supported channels */
	servo_position_t	values[PWM_OUTPUT_MAX_CHANNELS];
	unsigned			channel_count;
};

/*
 * ORB tag for PWM outputs.
 */
ORB_DECLARE(output_pwm);

/*
 * ioctl() definitions
 *
 * Note that ioctls and ORB updates should not be mixed, as the
 * behaviour of the system in this case is not defined.
 */
#define _PWM_SERVO_BASE		0x2a00

/** 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)

/** get default servo update rate */
#define PWM_SERVO_GET_DEFAULT_UPDATE_RATE _IOC(_PWM_SERVO_BASE, 2)

/** set alternate servo update rate */
#define PWM_SERVO_SET_UPDATE_RATE _IOC(_PWM_SERVO_BASE, 3)

/** get alternate servo update rate */
#define PWM_SERVO_GET_UPDATE_RATE _IOC(_PWM_SERVO_BASE, 4)

/** get the number of servos in *(unsigned *)arg */
#define PWM_SERVO_GET_COUNT	_IOC(_PWM_SERVO_BASE, 5)

/** selects servo update rates, one bit per servo. 0 = default (50Hz), 1 = alternate */
#define PWM_SERVO_SET_SELECT_UPDATE_RATE _IOC(_PWM_SERVO_BASE, 6)

/** check the selected update rates */
#define PWM_SERVO_GET_SELECT_UPDATE_RATE _IOC(_PWM_SERVO_BASE, 7)

/** set the 'ARM ok' bit, which activates the safety switch */
#define PWM_SERVO_SET_ARM_OK	_IOC(_PWM_SERVO_BASE, 8)

/** clear the 'ARM ok' bit, which deactivates the safety switch */
#define PWM_SERVO_CLEAR_ARM_OK	_IOC(_PWM_SERVO_BASE, 9)

/** start DSM bind */
#define DSM_BIND_START	_IOC(_PWM_SERVO_BASE, 10)

#define DSM2_BIND_PULSES 3	/* DSM_BIND_START ioctl parameter, pulses required to start dsm2 pairing */
#define DSMX_BIND_PULSES 7	/* DSM_BIND_START ioctl parameter, pulses required to start dsmx pairing */
#define DSMX8_BIND_PULSES 9 	/* DSM_BIND_START ioctl parameter, pulses required to start 8 or more channel dsmx pairing */

/** power up DSM receiver */
#define DSM_BIND_POWER_UP _IOC(_PWM_SERVO_BASE, 11)

/** set the PWM value for failsafe */
#define PWM_SERVO_SET_FAILSAFE_PWM	_IOC(_PWM_SERVO_BASE, 12)

/** get the PWM value for failsafe */
#define PWM_SERVO_GET_FAILSAFE_PWM	_IOC(_PWM_SERVO_BASE, 13)

/** set the PWM value when disarmed - should be no PWM (zero) by default */
#define PWM_SERVO_SET_DISARMED_PWM	_IOC(_PWM_SERVO_BASE, 14)

/** get the PWM value when disarmed */
#define PWM_SERVO_GET_DISARMED_PWM	_IOC(_PWM_SERVO_BASE, 15)

/** set the minimum PWM value the output will send */
#define PWM_SERVO_SET_MIN_PWM	_IOC(_PWM_SERVO_BASE, 16)

/** get the minimum PWM value the output will send */
#define PWM_SERVO_GET_MIN_PWM	_IOC(_PWM_SERVO_BASE, 17)

/** set the maximum PWM value the output will send */
#define PWM_SERVO_SET_MAX_PWM	_IOC(_PWM_SERVO_BASE, 18)

/** get the maximum PWM value the output will send */
#define PWM_SERVO_GET_MAX_PWM	_IOC(_PWM_SERVO_BASE, 19)

/** set the number of servos in (unsigned)arg - allows change of
 * split between servos and GPIO */
#define PWM_SERVO_SET_COUNT	_IOC(_PWM_SERVO_BASE, 20)

/** set the lockdown override flag to enable outputs in HIL */
#define PWM_SERVO_SET_DISABLE_LOCKDOWN		_IOC(_PWM_SERVO_BASE, 21)

/** get the lockdown override flag to enable outputs in HIL */
#define PWM_SERVO_GET_DISABLE_LOCKDOWN		_IOC(_PWM_SERVO_BASE, 22)

/** force safety switch off (to disable use of safety switch) */
#define PWM_SERVO_SET_FORCE_SAFETY_OFF		_IOC(_PWM_SERVO_BASE, 23)

/** force failsafe mode (failsafe values are set immediately even if failsafe condition not met) */
#define PWM_SERVO_SET_FORCE_FAILSAFE		_IOC(_PWM_SERVO_BASE, 24)

/** make failsafe non-recoverable (termination) if it occurs */
#define PWM_SERVO_SET_TERMINATION_FAILSAFE	_IOC(_PWM_SERVO_BASE, 25)

/** force safety switch on (to enable use of safety switch) */
#define PWM_SERVO_SET_FORCE_SAFETY_ON  _IOC(_PWM_SERVO_BASE, 26)

/*
 *
 *
 * WARNING WARNING WARNING! DO NOT EXCEED 31 IN IOC INDICES HERE!
 *
 *
 */

/** 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)

/** get the _n'th rate group's channels; *(uint32_t *)arg returns a bitmap of channels
 *  whose update rates must be the same.
 */
#define PWM_SERVO_GET_RATEGROUP(_n) _IOC(_PWM_SERVO_BASE, 0x60 + _n)

/*
 * Low-level PWM output interface.
 *
 * This is the low-level API to the platform-specific PWM driver.
 */

/**
 * Intialise the PWM servo outputs using the specified configuration.
 *
 * @param channel_mask	Bitmask of channels (LSB = channel 0) to enable.
 *			This allows some of the channels to remain configured
 *			as GPIOs or as another function.
 * @return		OK on success.
 */
__EXPORT extern int	up_pwm_servo_init(uint32_t channel_mask);

/**
 * De-initialise the PWM servo outputs.
 */
__EXPORT extern void	up_pwm_servo_deinit(void);

/**
 * Arm or disarm servo outputs.
 *
 * When disarmed, servos output no pulse.
 *
 * @bug This function should, but does not, guarantee that any pulse
 *      currently in progress is cleanly completed.
 *
 * @param armed		If true, outputs are armed; if false they
 *			are disarmed.
 */
__EXPORT extern void	up_pwm_servo_arm(bool armed);

/**
 * Set the servo update rate for all rate groups.
 *
 * @param rate		The update rate in Hz to set.
 * @return		OK on success, -ERANGE if an unsupported update rate is set.
 */
__EXPORT extern int	up_pwm_servo_set_rate(unsigned rate);

/**
 * Get a bitmap of output channels assigned to a given rate group.
 *
 * @param group		The rate group to query. Rate groups are assigned contiguously
 *			starting from zero.
 * @return		A bitmap of channels assigned to the rate group, or zero if
 *			the group number has no channels.
 */
__EXPORT extern uint32_t up_pwm_servo_get_rate_group(unsigned group);

/**
 * Set the update rate for a given rate group.
 *
 * @param group		The rate group whose update rate will be changed.
 * @param rate		The update rate in Hz.
 * @return		OK if the group was adjusted, -ERANGE if an unsupported update rate is set.
 */
__EXPORT extern int	up_pwm_servo_set_rate_group_update(unsigned group, unsigned rate);

/**
 * Set the current output value for a channel.
 *
 * @param channel	The channel to set.
 * @param value		The output pulse width in microseconds.
 */
__EXPORT extern int	up_pwm_servo_set(unsigned channel, servo_position_t value);

/**
 * Get the current output value for a channel.
 *
 * @param channel	The channel to read.
 * @return		The output pulse width in microseconds, or zero if
 *			outputs are not armed or not configured.
 */
__EXPORT extern servo_position_t up_pwm_servo_get(unsigned channel);

__END_DECLS