text: /****************************************************************************
   *
   *   Copyright (c) 2012-2015, 2017 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 fmu.cpp
   *
   * Driver/configurator for the PX4 FMU multi-purpose port on v1 and v2 boards.
   */
  
  #include <px4_config.h>
  #include <px4_log.h>
  #include <px4_module.h>
  #include <px4_getopt.h>
  
  #include <sys/types.h>
  #include <stdint.h>
  #include <stdbool.h>
  #include <float.h>
  #include <stdlib.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 <drivers/device/device.h>
  #include <drivers/device/i2c.h>
  #include <drivers/drv_pwm_output.h>
  #include <drivers/drv_input_capture.h>
  #include <drivers/drv_gpio.h>
  #include <drivers/drv_hrt.h>
  
  #include <board_config.h>
  
  #include <systemlib/px4_macros.h>
  #include <systemlib/systemlib.h>
  #include <systemlib/mixer/mixer.h>
  #include <systemlib/pwm_limit/pwm_limit.h>
  #include <systemlib/board_serial.h>
  #include <systemlib/param/param.h>
  #include <systemlib/perf_counter.h>
  #include <systemlib/scheduling_priorities.h>
  #include <drivers/drv_mixer.h>
  #include <drivers/drv_rc_input.h>
  #include <drivers/drv_input_capture.h>
  
  #include <lib/rc/sbus.h>
  #include <lib/rc/dsm.h>
  #include <lib/rc/st24.h>
  #include <lib/rc/sumd.h>
  
  #include <uORB/topics/actuator_controls.h>
  #include <uORB/topics/actuator_outputs.h>
  #include <uORB/topics/actuator_armed.h>
  #include <uORB/topics/vehicle_command.h>
  #include <uORB/topics/parameter_update.h>
  #include <uORB/topics/safety.h>
  #include <uORB/topics/adc_report.h>
  #include <uORB/topics/multirotor_motor_limits.h>
  
  #ifdef HRT_PPM_CHANNEL
  # include <systemlib/ppm_decode.h>
  #endif
  
  #include <systemlib/circuit_breaker.h>
  
  #define SCHEDULE_INTERVAL	2000	/**< The schedule interval in usec (500 Hz) */
  #define NAN_VALUE	(0.0f/0.0f)		/**< NaN value for throttle lock mode */
  #define BUTTON_SAFETY	px4_arch_gpioread(GPIO_BTN_SAFETY)
  #define CYCLE_COUNT 10			/* safety switch must be held for 1 second to activate */
  
  /*
   * Define the various LED flash sequences for each system state.
   */
  #define LED_PATTERN_FMU_OK_TO_ARM 		0x0003		/**< slow blinking			*/
  #define LED_PATTERN_FMU_REFUSE_TO_ARM 	0x5555		/**< fast blinking			*/
  #define LED_PATTERN_IO_ARMED 			0x5050		/**< long off, then double blink 	*/
  #define LED_PATTERN_FMU_ARMED 			0x5500		/**< long off, then quad blink 		*/
  #define LED_PATTERN_IO_FMU_ARMED 		0xffff		/**< constantly on			*/
  
  /** Mode given via CLI */
  enum PortMode {
  	PORT_MODE_UNSET = 0,
  	PORT_FULL_GPIO,
  	PORT_FULL_SERIAL,
  	PORT_FULL_PWM,
  	PORT_RC_IN,
  	PORT_GPIO_AND_SERIAL,
  	PORT_PWM_AND_SERIAL,
  	PORT_PWM_AND_GPIO,
  	PORT_PWM4,
  	PORT_PWM3,
  	PORT_PWM2,
  	PORT_PWM1,
  	PORT_PWM3CAP1,
  	PORT_PWM2CAP2,
  	PORT_CAPTURE,
  };
  
  
  #if !defined(BOARD_HAS_PWM)
  #  error "board_config.h needs to define BOARD_HAS_PWM"
  #endif
  class PX4FMU : public device::CDev, public ModuleBase<PX4FMU>
  {
  public:
  	enum Mode {
  		MODE_NONE,
  		MODE_1PWM,
  		MODE_2PWM,
  		MODE_2PWM2CAP,
  		MODE_3PWM,
  		MODE_3PWM1CAP,
  		MODE_4PWM,
  		MODE_6PWM,
  		MODE_8PWM,
  		MODE_4CAP,
  		MODE_5CAP,
  		MODE_6CAP,
  	};
  	PX4FMU(bool run_as_task);
  	virtual ~PX4FMU();
  
  	/** @see ModuleBase */
  	static int task_spawn(int argc, char *argv[]);
  
  	/** @see ModuleBase */
  	static PX4FMU *instantiate(int argc, char *argv[]);
  
  	/** @see ModuleBase */
  	static int custom_command(int argc, char *argv[]);
  
  	/** @see ModuleBase */
  	static int print_usage(const char *reason = nullptr);
  
  	/** @see ModuleBase::run() */
  	void run() override;
  
  	/**
  	 * run the main loop: if running as task, continuously iterate, otherwise execute only one single cycle
  	 */
  	void cycle();
  
  	/** @see ModuleBase::print_status() */
  	int print_status() override;
  
  	/** change the FMU mode of the running module */
  	static int fmu_new_mode(PortMode new_mode);
  
  	static int test();
  
  	static int fake(int argc, char *argv[]);
  
  	virtual int	ioctl(file *filp, int cmd, unsigned long arg);
  	virtual ssize_t	write(file *filp, const char *buffer, size_t len);
  
  	virtual int	init();
  
  	void dsm_bind_ioctl();
  
  	int		set_mode(Mode mode);
  	Mode		get_mode() { return _mode; }
  
  	int		set_pwm_alt_rate(unsigned rate);
  	int		set_pwm_alt_channels(uint32_t channels);
  
  	static int	set_i2c_bus_clock(unsigned bus, unsigned clock_hz);
  
  	static void	capture_trampoline(void *context, uint32_t chan_index,
  					   hrt_abstime edge_time, uint32_t edge_state,
  					   uint32_t overflow);
  
  	void update_pwm_trims();
  
  private:
  	enum RC_SCAN {
  		RC_SCAN_PPM = 0,
  		RC_SCAN_SBUS,
  		RC_SCAN_DSM,
  		RC_SCAN_SUMD,
  		RC_SCAN_ST24
  	};
  	enum RC_SCAN _rc_scan_state = RC_SCAN_SBUS;
  
  	char const *RC_SCAN_STRING[5] = {
  		"PPM",
  		"SBUS",
  		"DSM",
  		"SUMD",
  		"ST24"
  	};
  
  	hrt_abstime _rc_scan_begin = 0;
  	bool _rc_scan_locked = false;
  	bool _report_lock = true;
  
  	hrt_abstime _cycle_timestamp = 0;
  	hrt_abstime _last_safety_check = 0;
  	hrt_abstime _time_last_mix = 0;
  
  	static const unsigned _max_actuators = DIRECT_PWM_OUTPUT_CHANNELS;
  
  	Mode		_mode;
  	unsigned	_pwm_default_rate;
  	unsigned	_pwm_alt_rate;
  	uint32_t	_pwm_alt_rate_channels;
  	unsigned	_current_update_rate;
  	bool 		_run_as_task;
  	static struct work_s	_work;
  	int		_vehicle_cmd_sub;
  	int		_armed_sub;
  	int		_param_sub;
  	int		_adc_sub;
  	struct rc_input_values	_rc_in;
  	float		_analog_rc_rssi_volt;
  	bool		_analog_rc_rssi_stable;
  	orb_advert_t	_to_input_rc;
  	orb_advert_t	_outputs_pub;
  	unsigned	_num_outputs;
  	int		_class_instance;
  	int		_rcs_fd;
  	uint8_t _rcs_buf[SBUS_BUFFER_SIZE];
  
  	bool		_throttle_armed;
  	bool		_pwm_on;
  	uint32_t	_pwm_mask;
  	bool		_pwm_initialized;
  
  	MixerGroup	*_mixers;
  
  	uint32_t	_groups_required;
  	uint32_t	_groups_subscribed;
  	int		_control_subs[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];
  	actuator_controls_s _controls[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];
  	orb_id_t	_control_topics[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];
  	pollfd	_poll_fds[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];
  	unsigned	_poll_fds_num;
  
  	uint16_t raw_rc_values[input_rc_s::RC_INPUT_MAX_CHANNELS];
  	uint16_t raw_rc_count;
  
  	static pwm_limit_t	_pwm_limit;
  	static actuator_armed_s	_armed;
  	uint16_t	_failsafe_pwm[_max_actuators];
  	uint16_t	_disarmed_pwm[_max_actuators];
  	uint16_t	_min_pwm[_max_actuators];
  	uint16_t	_max_pwm[_max_actuators];
  	uint16_t	_trim_pwm[_max_actuators];
  	uint16_t	_reverse_pwm_mask;
  	unsigned	_num_failsafe_set;
  	unsigned	_num_disarmed_set;
  	bool		_safety_off;
  	bool		_safety_disabled;
  	orb_advert_t		_to_safety;
  	orb_advert_t      _to_mixer_status; 	///< mixer status flags
  
  	float _mot_t_max;	// maximum rise time for motor (slew rate limiting)
  	float _thr_mdl_fac;	// thrust to pwm modelling factor
  
  	perf_counter_t	_ctl_latency;
  
  	static bool	arm_nothrottle()
  	{
  		return ((_armed.prearmed && !_armed.armed) || _armed.in_esc_calibration_mode);
  	}
  
  	static void	cycle_trampoline(void *arg);
  	int 		start();
  
  	static int	control_callback(uintptr_t handle,
  					 uint8_t control_group,
  					 uint8_t control_index,
  					 float &input);
  	void		capture_callback(uint32_t chan_index,
  					 hrt_abstime edge_time, uint32_t edge_state, uint32_t overflow);
  	void		subscribe();
  	int			set_pwm_rate(unsigned rate_map, unsigned default_rate, unsigned alt_rate);
  	int			pwm_ioctl(file *filp, int cmd, unsigned long arg);
  	void		update_pwm_rev_mask();
  	void		publish_pwm_outputs(uint16_t *values, size_t numvalues);
  	void		update_pwm_out_state(bool on);
  	void		pwm_output_set(unsigned i, unsigned value);
  	void		update_params();
  
  	struct GPIOConfig {
  		uint32_t	input;
  		uint32_t	output;
  		uint32_t	alt;
  	};
  
  #if defined(BOARD_HAS_FMU_GPIO)
  	static const GPIOConfig	_gpio_tab[];
  	static const unsigned	_ngpio;
  #endif
  	static void		sensor_reset(int ms);
  	static void		peripheral_reset(int ms);
  	int		gpio_reset(void);
  	int		gpio_set_function(uint32_t gpios, int function);
  	int		gpio_write(uint32_t gpios, int function);
  	int		gpio_read(uint32_t *value);
  	int		gpio_ioctl(file *filp, int cmd, unsigned long arg);
  
  	int		capture_ioctl(file *filp, int cmd, unsigned long arg);
  
  	PX4FMU(const PX4FMU &) = delete;
  	PX4FMU operator=(const PX4FMU &) = delete;
  
  	void fill_rc_in(uint16_t raw_rc_count_local,
  			uint16_t raw_rc_values_local[input_rc_s::RC_INPUT_MAX_CHANNELS],
  			hrt_abstime now, bool frame_drop, bool failsafe,
  			unsigned frame_drops, int rssi);
  	void dsm_bind_ioctl(int dsmMode);
  	void set_rc_scan_state(RC_SCAN _rc_scan_state);
  	void rc_io_invert();
  	void rc_io_invert(bool invert);
  	void safety_check_button(void);
  	void flash_safety_button(void);
  };
  
  #if defined(BOARD_HAS_FMU_GPIO)
  const PX4FMU::GPIOConfig PX4FMU::_gpio_tab[] =	BOARD_FMU_GPIO_TAB;
  
  const unsigned		PX4FMU::_ngpio = arraySize(PX4FMU::_gpio_tab);
  #endif
  pwm_limit_t		PX4FMU::_pwm_limit;
  actuator_armed_s	PX4FMU::_armed = {};
  work_s	PX4FMU::_work = {};
  
  PX4FMU::PX4FMU(bool run_as_task) :
  	CDev("fmu", PX4FMU_DEVICE_PATH),
  	_mode(MODE_NONE),
  	_pwm_default_rate(50),
  	_pwm_alt_rate(50),
  	_pwm_alt_rate_channels(0),
  	_current_update_rate(0),
  	_run_as_task(run_as_task),
  	_vehicle_cmd_sub(-1),
  	_armed_sub(-1),
  	_param_sub(-1),
  	_adc_sub(-1),
  	_rc_in{},
  	_analog_rc_rssi_volt(-1.0f),
  	_analog_rc_rssi_stable(false),
  	_to_input_rc(nullptr),
  	_outputs_pub(nullptr),
  	_num_outputs(0),
  	_class_instance(0),
  	_rcs_fd(-1),
  	_throttle_armed(false),
  	_pwm_on(false),
  	_pwm_mask(0),
  	_pwm_initialized(false),
  	_mixers(nullptr),
  	_groups_required(0),
  	_groups_subscribed(0),
  	_control_subs{ -1},
  	_poll_fds_num(0),
  	raw_rc_count(0),
  	_failsafe_pwm{0},
  	_disarmed_pwm{0},
  	_reverse_pwm_mask(0),
  	_num_failsafe_set(0),
  	_num_disarmed_set(0),
  	_safety_off(false),
  	_safety_disabled(false),
  	_to_safety(nullptr),
  	_to_mixer_status(nullptr),
  	_mot_t_max(0.0f),
  	_thr_mdl_fac(0.0f),
  	_ctl_latency(perf_alloc(PC_ELAPSED, "ctl_lat"))
  {
  	for (unsigned i = 0; i < _max_actuators; i++) {
  		_min_pwm[i] = PWM_DEFAULT_MIN;
  		_max_pwm[i] = PWM_DEFAULT_MAX;
  		_trim_pwm[i] = PWM_DEFAULT_TRIM;
  	}
  
  	_control_topics[0] = ORB_ID(actuator_controls_0);
  	_control_topics[1] = ORB_ID(actuator_controls_1);
  	_control_topics[2] = ORB_ID(actuator_controls_2);
  	_control_topics[3] = ORB_ID(actuator_controls_3);
  
  	memset(_controls, 0, sizeof(_controls));
  	memset(_poll_fds, 0, sizeof(_poll_fds));
  
  	// Safely initialize armed flags.
  	_armed.armed = false;
  	_armed.prearmed = false;
  	_armed.ready_to_arm = false;
  	_armed.lockdown = false;
  	_armed.force_failsafe = false;
  	_armed.in_esc_calibration_mode = false;
  
  	// rc input, published to ORB
  	_rc_in.input_source = input_rc_s::RC_INPUT_SOURCE_PX4FMU_PPM;
  
  	// initialize raw_rc values and count
  	for (unsigned i = 0; i < input_rc_s::RC_INPUT_MAX_CHANNELS; i++) {
  		raw_rc_values[i] = UINT16_MAX;
  	}
  
  	raw_rc_count = 0;
  
  #ifdef GPIO_SBUS_INV
  	// this board has a GPIO to control SBUS inversion
  	px4_arch_configgpio(GPIO_SBUS_INV);
  #endif
  
  	// If there is no safety button, disable it on boot.
  #ifndef GPIO_BTN_SAFETY
  	_safety_off = true;
  #endif
  
  	/* only enable this during development */
  	_debug_enabled = false;
  }
  
  PX4FMU::~PX4FMU()
  {
  	for (unsigned i = 0; i < actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS; i++) {
  		if (_control_subs[i] > 0) {
  			orb_unsubscribe(_control_subs[i]);
  			_control_subs[i] = -1;
  		}
  	}
  
  	orb_unsubscribe(_armed_sub);
  	orb_unsubscribe(_param_sub);
  
  	orb_unadvertise(_to_input_rc);
  	orb_unadvertise(_outputs_pub);
  	orb_unadvertise(_to_safety);
  	orb_unadvertise(_to_mixer_status);
  
  	/* make sure servos are off */
  	up_pwm_servo_deinit();
  
  #ifdef RC_SERIAL_PORT
  	dsm_deinit();
  #endif
  
  	/* note - someone else is responsible for restoring the GPIO config */
  
  	/* clean up the alternate device node */
  	unregister_class_devname(PWM_OUTPUT_BASE_DEVICE_PATH, _class_instance);
  
  	perf_free(_ctl_latency);
  }
  
  int
  PX4FMU::init()
  {
  	int ret;
  
  	/* do regular cdev init */
  	ret = CDev::init();
  
  	if (ret != OK) {
  		return ret;
  	}
  
  	// XXX best would be to register / de-register the device depending on modes
  
  	/* try to claim the generic PWM output device node as well - it's OK if we fail at this */
  	_class_instance = register_class_devname(PWM_OUTPUT_BASE_DEVICE_PATH);
  
  	if (_class_instance == CLASS_DEVICE_PRIMARY) {
  		/* lets not be too verbose */
  	} else if (_class_instance < 0) {
  		PX4_ERR("FAILED registering class device");
  	}
  
  	_safety_disabled = circuit_breaker_enabled("CBRK_IO_SAFETY", CBRK_IO_SAFETY_KEY);
  
  	/* force a reset of the update rate */
  	_current_update_rate = 0;
  
  	_armed_sub = orb_subscribe(ORB_ID(actuator_armed));
  	_param_sub = orb_subscribe(ORB_ID(parameter_update));
  	_adc_sub = orb_subscribe(ORB_ID(adc_report));
  
  	/* initialize PWM limit lib */
  	pwm_limit_init(&_pwm_limit);
  
  	update_pwm_rev_mask();
  
  #ifdef RC_SERIAL_PORT
  
  #  ifdef RF_RADIO_POWER_CONTROL
  	// power radio on
  	RF_RADIO_POWER_CONTROL(true);
  #  endif
  	_vehicle_cmd_sub = orb_subscribe(ORB_ID(vehicle_command));
  	// dsm_init sets some file static variables and returns a file descriptor
  	_rcs_fd = dsm_init(RC_SERIAL_PORT);
  	// assume SBUS input
  	sbus_config(_rcs_fd, false);
  #  ifdef GPIO_PPM_IN
  	// disable CPPM input by mapping it away from the timer capture input
  	px4_arch_unconfiggpio(GPIO_PPM_IN);
  #  endif
  #endif
  
  	// Getting initial parameter values
  	update_params();
  
  	for (unsigned i = 0; i < _max_actuators; i++) {
  		char pname[16];
  		sprintf(pname, "PWM_AUX_TRIM%d", i + 1);
  		param_find(pname);
  	}
  
  	return 0;
  }
  
  void
  PX4FMU::safety_check_button(void)
  {
  #ifdef GPIO_BTN_SAFETY
  	static int counter = 0;
  	/*
  	 * Debounce the safety button, change state if it has been held for long enough.
  	 *
  	 */
  	bool safety_button_pressed = BUTTON_SAFETY;
  
  	/*
  	 * Keep pressed for a while to arm.
  	 *
  	 * Note that the counting sequence has to be same length
  	 * for arming / disarming in order to end up as proper
  	 * state machine, keep ARM_COUNTER_THRESHOLD the same
  	 * length in all cases of the if/else struct below.
  	 */
  	if (safety_button_pressed && !_safety_off) {
  
  		if (counter < CYCLE_COUNT) {
  			counter++;
  
  		} else if (counter == CYCLE_COUNT) {
  			/* switch to armed state */
  			_safety_off = true;
  			counter++;
  		}
  
  	} else if (safety_button_pressed && _safety_off) {
  
  		if (counter < CYCLE_COUNT) {
  			counter++;
  
  		} else if (counter == CYCLE_COUNT) {
  			/* change to disarmed state and notify the FMU */
  			_safety_off = false;
  			counter++;
  		}
  
  	} else {
  		counter = 0;
  	}
  
  #endif
  }
  
  void
  PX4FMU::flash_safety_button()
  {
  #ifdef GPIO_BTN_SAFETY
  
  	/* Select the appropriate LED flash pattern depending on the current arm state */
  	uint16_t pattern = LED_PATTERN_FMU_REFUSE_TO_ARM;
  
  	/* cycle the blink state machine at 10Hz */
  	static int blink_counter = 0;
  
  	if (_safety_off) {
  		if (_armed.armed) {
  			pattern = LED_PATTERN_IO_FMU_ARMED;
  
  		} else {
  			pattern = LED_PATTERN_IO_ARMED;
  		}
  
  	} else if (_armed.armed) {
  		pattern = LED_PATTERN_FMU_ARMED;
  
  	} else {
  		pattern = LED_PATTERN_FMU_OK_TO_ARM;
  
  	}
  
  	/* Turn the LED on if we have a 1 at the current bit position */
  	px4_arch_gpiowrite(GPIO_LED_SAFETY, !(pattern & (1 << blink_counter++)));
  
  	if (blink_counter > 15) {
  		blink_counter = 0;
  	}
  
  #endif
  }
  
  int
  PX4FMU::set_mode(Mode mode)
  {
  	unsigned old_mask = _pwm_mask;
  
  	/*
  	 * Configure for PWM output.
  	 *
  	 * Note that regardless of the configured mode, the task is always
  	 * listening and mixing; the mode just selects which of the channels
  	 * are presented on the output pins.
  	 */
  	switch (mode) {
  	case MODE_1PWM:
  		/* default output rates */
  		_pwm_default_rate = 50;
  		_pwm_alt_rate = 50;
  		_pwm_alt_rate_channels = 0;
  		_pwm_mask = 0x1;
  		_pwm_initialized = false;
  		_num_outputs = 1;
  		break;
  
  #if defined(BOARD_HAS_CAPTURE)
  
  	case MODE_2PWM2CAP:	// v1 multi-port with flow control lines as PWM
  		up_input_capture_set(2, Rising, 0, NULL, NULL);
  		up_input_capture_set(3, Rising, 0, NULL, NULL);
  		DEVICE_DEBUG("MODE_2PWM2CAP");
  #endif
  
  	/* FALLTHROUGH */
  
  	case MODE_2PWM:	// v1 multi-port with flow control lines as PWM
  		DEVICE_DEBUG("MODE_2PWM");
  
  		/* default output rates */
  		_pwm_default_rate = 50;
  		_pwm_alt_rate = 50;
  		_pwm_alt_rate_channels = 0;
  		_pwm_mask = 0x3;
  		_pwm_initialized = false;
  		_num_outputs = 2;
  
  		break;
  
  #if defined(BOARD_HAS_CAPTURE)
  
  	case MODE_3PWM1CAP:	// v1 multi-port with flow control lines as PWM
  		DEVICE_DEBUG("MODE_3PWM1CAP");
  		up_input_capture_set(3, Rising, 0, NULL, NULL);
  #endif
  
  	/* FALLTHROUGH */
  
  	case MODE_3PWM:	// v1 multi-port with flow control lines as PWM
  		DEVICE_DEBUG("MODE_3PWM");
  
  		/* default output rates */
  		_pwm_default_rate = 50;
  		_pwm_alt_rate = 50;
  		_pwm_alt_rate_channels = 0;
  		_pwm_mask = 0x7;
  		_pwm_initialized = false;
  		_num_outputs = 3;
  
  		break;
  
  	case MODE_4PWM: // v1 or v2 multi-port as 4 PWM outs
  		DEVICE_DEBUG("MODE_4PWM");
  
  		/* default output rates */
  		_pwm_default_rate = 50;
  		_pwm_alt_rate = 50;
  		_pwm_alt_rate_channels = 0;
  		_pwm_mask = 0xf;
  		_pwm_initialized = false;
  		_num_outputs = 4;
  
  		break;
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 6
  
  	case MODE_6PWM:
  		DEVICE_DEBUG("MODE_6PWM");
  
  		/* default output rates */
  		_pwm_default_rate = 50;
  		_pwm_alt_rate = 50;
  		_pwm_alt_rate_channels = 0;
  		_pwm_mask = 0x3f;
  		_pwm_initialized = false;
  		_num_outputs = 6;
  
  		break;
  #endif
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 8
  
  	case MODE_8PWM: // AeroCore PWMs as 8 PWM outs
  		DEVICE_DEBUG("MODE_8PWM");
  		/* default output rates */
  		_pwm_default_rate = 50;
  		_pwm_alt_rate = 50;
  		_pwm_alt_rate_channels = 0;
  		_pwm_mask = 0xff;
  		_pwm_initialized = false;
  		_num_outputs = 8;
  
  		break;
  #endif
  
  	case MODE_NONE:
  		DEVICE_DEBUG("MODE_NONE");
  
  		_pwm_default_rate = 10;	/* artificially reduced output rate */
  		_pwm_alt_rate = 10;
  		_pwm_alt_rate_channels = 0;
  		_pwm_mask = 0x0;
  		_pwm_initialized = false;
  		_num_outputs = 0;
  
  		if (old_mask != _pwm_mask) {
  			/* disable servo outputs - no need to set rates */
  			up_pwm_servo_deinit();
  		}
  
  		break;
  
  	default:
  		return -EINVAL;
  	}
  
  	_mode = mode;
  	return OK;
  }
  
  /* When set_pwm_rate is called from either of the 2 IOCTLs:
   *
   * PWM_SERVO_SET_UPDATE_RATE        - Sets the "alternate" channel's rate to the callers's rate specified
   *                                    and the non "alternate" channels to the _pwm_default_rate.
   *
   *                                    rate_map     = _pwm_alt_rate_channels
   *                                    default_rate = _pwm_default_rate
   *                                    alt_rate     = arg of IOCTL (see rates)
   *
   * PWM_SERVO_SET_SELECT_UPDATE_RATE - The caller's specified rate map selects the "alternate" channels
   *                                    to be set to the alt rate. (_pwm_alt_rate)
   *                                    All other channels are set to the default rate. (_pwm_default_rate)
   *
   *                                    rate_map     = arg of IOCTL
   *                                    default_rate = _pwm_default_rate
   *                                    alt_rate     = _pwm_alt_rate
  
   *  rate_map                        - A mask of 1's for the channels to be set to the
   *                                    alternate rate.
   *                                    N.B. All channels is a given group must be set
   *                                    to the same rate/mode. (default or alt)
   * rates:
   *   alt_rate, default_rate           For PWM is 25 or 400Hz
   *                                    For Oneshot there is no rate, 0 is therefore used
   *                                    to  select Oneshot mode
   */
  int
  PX4FMU::set_pwm_rate(uint32_t rate_map, unsigned default_rate, unsigned alt_rate)
  {
  	PX4_DEBUG("set_pwm_rate %x %u %u", rate_map, default_rate, alt_rate);
  
  	for (unsigned pass = 0; pass < 2; pass++) {
  
  		/* We should note that group is iterated over from 0 to _max_actuators.
  		 * This allows for the ideal worlds situation: 1 channel per group
  		 * configuration.
  		 *
  		 * This is typically not what HW supports. A group represents a timer
  		 * and channels belongs to a timer.
  		 * Therefore all channels in a group are dependent on the timer's
  		 * common settings and can not be independent in terms of count frequency
  		 * (granularity of pulse width) and rate (period of repetition).
  		 *
  		 * To say it another way, all channels in a group moust have the same
  		 * rate and mode. (See rates above.)
  		 */
  
  		for (unsigned group = 0; group < _max_actuators; group++) {
  
  			// get the channel mask for this rate group
  			uint32_t mask = up_pwm_servo_get_rate_group(group);
  
  			if (mask == 0) {
  				continue;
  			}
  
  			// all channels in the group must be either default or alt-rate
  			uint32_t alt = rate_map & mask;
  
  			if (pass == 0) {
  				// preflight
  				if ((alt != 0) && (alt != mask)) {
  					PX4_WARN("rate group %u mask %x bad overlap %x", group, mask, alt);
  					// not a legal map, bail
  					return -EINVAL;
  				}
  
  			} else {
  				// set it - errors here are unexpected
  				if (alt != 0) {
  					if (up_pwm_servo_set_rate_group_update(group, alt_rate) != OK) {
  						PX4_WARN("rate group set alt failed");
  						return -EINVAL;
  					}
  
  				} else {
  					if (up_pwm_servo_set_rate_group_update(group, default_rate) != OK) {
  						PX4_WARN("rate group set default failed");
  						return -EINVAL;
  					}
  				}
  			}
  		}
  	}
  
  	_pwm_alt_rate_channels = rate_map;
  	_pwm_default_rate = default_rate;
  	_pwm_alt_rate = alt_rate;
  
  	return OK;
  }
  
  int
  PX4FMU::set_pwm_alt_rate(unsigned rate)
  {
  	return set_pwm_rate(_pwm_alt_rate_channels, _pwm_default_rate, rate);
  }
  
  int
  PX4FMU::set_pwm_alt_channels(uint32_t channels)
  {
  	return set_pwm_rate(channels, _pwm_default_rate, _pwm_alt_rate);
  }
  
  int
  PX4FMU::set_i2c_bus_clock(unsigned bus, unsigned clock_hz)
  {
  	return device::I2C::set_bus_clock(bus, clock_hz);
  }
  
  void
  PX4FMU::subscribe()
  {
  	/* subscribe/unsubscribe to required actuator control groups */
  	uint32_t sub_groups = _groups_required & ~_groups_subscribed;
  	uint32_t unsub_groups = _groups_subscribed & ~_groups_required;
  	_poll_fds_num = 0;
  
  	for (unsigned i = 0; i < actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS; i++) {
  		if (sub_groups & (1 << i)) {
  			DEVICE_DEBUG("subscribe to actuator_controls_%d", i);
  			_control_subs[i] = orb_subscribe(_control_topics[i]);
  		}
  
  		if (unsub_groups & (1 << i)) {
  			DEVICE_DEBUG("unsubscribe from actuator_controls_%d", i);
  			orb_unsubscribe(_control_subs[i]);
  			_control_subs[i] = -1;
  		}
  
  		if (_control_subs[i] > 0) {
  			_poll_fds[_poll_fds_num].fd = _control_subs[i];
  			_poll_fds[_poll_fds_num].events = POLLIN;
  			_poll_fds_num++;
  		}
  	}
  }
  
  void
  PX4FMU::update_pwm_rev_mask()
  {
  	_reverse_pwm_mask = 0;
  
  	for (unsigned i = 0; i < _max_actuators; i++) {
  		char pname[16];
  		int32_t ival;
  
  		/* fill the channel reverse mask from parameters */
  		sprintf(pname, "PWM_AUX_REV%d", i + 1);
  		param_t param_h = param_find(pname);
  
  		if (param_h != PARAM_INVALID) {
  			param_get(param_h, &ival);
  			_reverse_pwm_mask |= ((int16_t)(ival != 0)) << i;
  		}
  	}
  }
  
  void
  PX4FMU::update_pwm_trims()
  {
  	PX4_DEBUG("update_pwm_trims");
  
  	if (_mixers != nullptr) {
  
  		int16_t values[_max_actuators] = {};
  
  		for (unsigned i = 0; i < _max_actuators; i++) {
  			char pname[16];
  			float pval;
  
  			/* fill the struct from parameters */
  			sprintf(pname, "PWM_AUX_TRIM%d", i + 1);
  			param_t param_h = param_find(pname);
  
  			if (param_h != PARAM_INVALID) {
  				param_get(param_h, &pval);
  				values[i] = (int16_t)(10000 * pval);
  				PX4_DEBUG("%s: %d", pname, values[i]);
  			}
  		}
  
  		/* copy the trim values to the mixer offsets */
  		unsigned n_out = _mixers->set_trims(values, _max_actuators);
  		PX4_DEBUG("set %d trims", n_out);
  	}
  }
  
  void
  PX4FMU::publish_pwm_outputs(uint16_t *values, size_t numvalues)
  {
  	actuator_outputs_s outputs = {};
  	outputs.noutputs = numvalues;
  	outputs.timestamp = hrt_absolute_time();
  
  	for (size_t i = 0; i < _max_actuators; ++i) {
  		outputs.output[i] = i < numvalues ? (float)values[i] : 0;
  	}
  
  	if (_outputs_pub == nullptr) {
  		int instance = _class_instance;
  		_outputs_pub = orb_advertise_multi(ORB_ID(actuator_outputs), &outputs, &instance, ORB_PRIO_DEFAULT);
  
  	} else {
  		orb_publish(ORB_ID(actuator_outputs), _outputs_pub, &outputs);
  	}
  }
  
  int
  PX4FMU::task_spawn(int argc, char *argv[])
  {
  	bool run_as_task = false;
  	bool error_flag = false;
  
  	int myoptind = 1;
  	int ch;
  	const char *myoptarg = nullptr;
  
  	while ((ch = px4_getopt(argc, argv, "t", &myoptind, &myoptarg)) != EOF) {
  		switch (ch) {
  		case 't':
  			run_as_task = true;
  			break;
  
  		case '?':
  			error_flag = true;
  			break;
  
  		default:
  			PX4_WARN("unrecognized flag");
  			error_flag = true;
  			break;
  		}
  	}
  
  	if (error_flag) {
  		return -1;
  	}
  
  
  	if (!run_as_task) {
  
  		/* schedule a cycle to start things */
  
  		int ret = work_queue(HPWORK, &_work, (worker_t)&PX4FMU::cycle_trampoline, nullptr, 0);
  
  		if (ret < 0) {
  			return ret;
  		}
  
  		_task_id = task_id_is_work_queue;
  
  	} else {
  
  		/* start the IO interface task */
  
  		_task_id = px4_task_spawn_cmd("fmu",
  					      SCHED_DEFAULT,
  					      SCHED_PRIORITY_FAST_DRIVER - 1,
  					      1310,
  					      (px4_main_t)&run_trampoline,
  					      nullptr);
  
  		if (_task_id < 0) {
  			_task_id = -1;
  			return -errno;
  		}
  	}
  
  	// wait until task is up & running (the mode_* commands depend on it)
  	if (wait_until_running() < 0) {
  		_task_id = -1;
  		return -1;
  	}
  
  	return PX4_OK;
  }
  
  void
  PX4FMU::cycle_trampoline(void *arg)
  {
  	PX4FMU *dev = reinterpret_cast<PX4FMU *>(arg);
  
  	// check if the trampoline is called for the first time
  	if (!dev) {
  		dev = new PX4FMU(false);
  
  		if (!dev) {
  			PX4_ERR("alloc failed");
  			return;
  		}
  
  		if (dev->init() != 0) {
  			PX4_ERR("init failed");
  			delete dev;
  			return;
  		}
  
  		_object = dev;
  	}
  
  	dev->cycle();
  }
  
  void
  PX4FMU::capture_trampoline(void *context, uint32_t chan_index,
  			   hrt_abstime edge_time, uint32_t edge_state, uint32_t overflow)
  {
  	PX4FMU *dev = reinterpret_cast<PX4FMU *>(context);
  	dev->capture_callback(chan_index, edge_time, edge_state, overflow);
  }
  
  void
  PX4FMU::capture_callback(uint32_t chan_index,
  			 hrt_abstime edge_time, uint32_t edge_state, uint32_t overflow)
  {
  	fprintf(stdout, "FMU: Capture chan:%d time:%lld state:%d overflow:%d\n", chan_index, edge_time, edge_state, overflow);
  }
  
  void
  PX4FMU::fill_rc_in(uint16_t raw_rc_count_local,
  		   uint16_t raw_rc_values_local[input_rc_s::RC_INPUT_MAX_CHANNELS],
  		   hrt_abstime now, bool frame_drop, bool failsafe,
  		   unsigned frame_drops, int rssi = -1)
  {
  	// fill rc_in struct for publishing
  	_rc_in.channel_count = raw_rc_count_local;
  
  	if (_rc_in.channel_count > input_rc_s::RC_INPUT_MAX_CHANNELS) {
  		_rc_in.channel_count = input_rc_s::RC_INPUT_MAX_CHANNELS;
  	}
  
  	unsigned valid_chans = 0;
  
  	for (unsigned i = 0; i < _rc_in.channel_count; i++) {
  		_rc_in.values[i] = raw_rc_values_local[i];
  
  		if (raw_rc_values_local[i] != UINT16_MAX) {
  			valid_chans++;
  		}
  
  		// once filled, reset values back to default
  		raw_rc_values[i] = UINT16_MAX;
  	}
  
  	_rc_in.timestamp = now;
  	_rc_in.timestamp_last_signal = _rc_in.timestamp;
  	_rc_in.rc_ppm_frame_length = 0;
  
  	/* fake rssi if no value was provided */
  	if (rssi == -1) {
  
  		/* set RSSI if analog RSSI input is present */
  		if (_analog_rc_rssi_stable) {
  			float rssi_analog = ((_analog_rc_rssi_volt - 0.2f) / 3.0f) * 100.0f;
  
  			if (rssi_analog > 100.0f) {
  				rssi_analog = 100.0f;
  			}
  
  			if (rssi_analog < 0.0f) {
  				rssi_analog = 0.0f;
  			}
  
  			_rc_in.rssi = rssi_analog;
  
  		} else {
  			_rc_in.rssi = 255;
  		}
  
  	} else {
  		_rc_in.rssi = rssi;
  	}
  
  	if (valid_chans == 0) {
  		_rc_in.rssi = 0;
  	}
  
  	_rc_in.rc_failsafe = failsafe;
  	_rc_in.rc_lost = (valid_chans == 0);
  	_rc_in.rc_lost_frame_count = frame_drops;
  	_rc_in.rc_total_frame_count = 0;
  }
  
  #ifdef RC_SERIAL_PORT
  void PX4FMU::set_rc_scan_state(RC_SCAN newState)
  {
  //    PX4_WARN("RCscan: %s failed, trying %s", PX4FMU::RC_SCAN_STRING[_rc_scan_state], PX4FMU::RC_SCAN_STRING[newState]);
  	_rc_scan_begin = 0;
  	_rc_scan_state = newState;
  }
  
  void PX4FMU::rc_io_invert(bool invert)
  {
  	INVERT_RC_INPUT(invert);
  }
  #endif
  
  void
  PX4FMU::pwm_output_set(unsigned i, unsigned value)
  {
  	if (_pwm_initialized) {
  		up_pwm_servo_set(i, value);
  	}
  }
  
  void
  PX4FMU::update_pwm_out_state(bool on)
  {
  	if (on && !_pwm_initialized && _pwm_mask != 0) {
  		up_pwm_servo_init(_pwm_mask);
  		set_pwm_rate(_pwm_alt_rate_channels, _pwm_default_rate, _pwm_alt_rate);
  		_pwm_initialized = true;
  	}
  
  	up_pwm_servo_arm(on);
  }
  
  void
  PX4FMU::run()
  {
  	if (init() != 0) {
  		PX4_ERR("init failed");
  		exit_and_cleanup();
  		return;
  	}
  
  	cycle();
  }
  
  void
  PX4FMU::cycle()
  {
  	while (true) {
  
  		if (_groups_subscribed != _groups_required) {
  			subscribe();
  			_groups_subscribed = _groups_required;
  			/* force setting update rate */
  			_current_update_rate = 0;
  		}
  
  		int poll_timeout = 5; // needs to be small enough so that we don't miss RC input data
  
  		if (!_run_as_task) {
  			/*
  			 * Adjust actuator topic update rate to keep up with
  			 * the highest servo update rate configured.
  			 *
  			 * We always mix at max rate; some channels may update slower.
  			 */
  			unsigned max_rate = (_pwm_default_rate > _pwm_alt_rate) ? _pwm_default_rate : _pwm_alt_rate;
  
  			if (_current_update_rate != max_rate) {
  				_current_update_rate = max_rate;
  				int update_rate_in_ms = int(1000 / _current_update_rate);
  
  				/* reject faster than 500 Hz updates */
  				if (update_rate_in_ms < 2) {
  					update_rate_in_ms = 2;
  				}
  
  				/* reject slower than 10 Hz updates */
  				if (update_rate_in_ms > 100) {
  					update_rate_in_ms = 100;
  				}
  
  				PX4_DEBUG("adjusted actuator update interval to %ums", update_rate_in_ms);
  
  				for (unsigned i = 0; i < actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS; i++) {
  					if (_control_subs[i] > 0) {
  						orb_set_interval(_control_subs[i], update_rate_in_ms);
  					}
  				}
  
  				// set to current max rate, even if we are actually checking slower/faster
  				_current_update_rate = max_rate;
  			}
  
  			/* check if anything updated */
  			poll_timeout = 0;
  		}
  
  		/* wait for an update */
  		unsigned n_updates = 0;
  		int ret = ::poll(_poll_fds, _poll_fds_num, poll_timeout);
  
  		/* this would be bad... */
  		if (ret < 0) {
  			DEVICE_LOG("poll error %d", errno);
  
  		} else if (ret == 0) {
  			/* timeout: no control data, switch to failsafe values */
  			//			PX4_WARN("no PWM: failsafe");
  
  		} else {
  			perf_begin(_ctl_latency);
  
  			/* get controls for required topics */
  			unsigned poll_id = 0;
  
  			for (unsigned i = 0; i < actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS; i++) {
  				if (_control_subs[i] > 0) {
  					if (_poll_fds[poll_id].revents & POLLIN) {
  						if (i == 0) {
  							n_updates++;
  						}
  
  						orb_copy(_control_topics[i], _control_subs[i], &_controls[i]);
  
  #if defined(DEBUG_BUILD)
  
  						static int main_out_latency = 0;
  						static int sum_latency = 0;
  						static uint64_t last_cycle_time = 0;
  
  						if (i == 0) {
  							uint64_t now = hrt_absolute_time();
  							uint64_t latency = now - _controls[i].timestamp;
  
  							if (latency > main_out_latency) { main_out_latency = latency; }
  
  							sum_latency += latency;
  
  							if ((now - last_cycle_time) >= 1000000) {
  								last_cycle_time = now;
  								PX4_DEBUG("pwm max latency: %d, avg: %5.3f", main_out_latency, (double)(sum_latency / 100.0));
  								main_out_latency = latency;
  								sum_latency = 0;
  							}
  						}
  
  #endif
  					}
  
  					poll_id++;
  				}
  
  				/* During ESC calibration, we overwrite the throttle value. */
  				if (i == 0 && _armed.in_esc_calibration_mode) {
  
  					/* Set all controls to 0 */
  					memset(&_controls[i], 0, sizeof(_controls[i]));
  
  					/* except thrust to maximum. */
  					_controls[i].control[3] = 1.0f;
  
  					/* Switch off the PWM limit ramp for the calibration. */
  					_pwm_limit.state = PWM_LIMIT_STATE_ON;
  				}
  			}
  		} // poll_fds
  
  		/* run the mixers on every cycle */
  		{
  			/* can we mix? */
  			if (_mixers != nullptr) {
  
  				hrt_abstime now = hrt_absolute_time();
  				float dt = (now - _time_last_mix) / 1e6f;
  				_time_last_mix = now;
  
  				if (dt < 0.0001f) {
  					dt = 0.0001f;
  
  				} else if (dt > 0.02f) {
  					dt = 0.02f;
  				}
  
  				if (_mot_t_max > FLT_EPSILON) {
  					// maximum value the ouputs of the multirotor mixer are allowed to change in this cycle
  					// factor 2 is needed because actuator ouputs are in the range [-1,1]
  					float delta_out_max = 2.0f * 1000.0f * dt / (_max_pwm[0] - _min_pwm[0]) / _mot_t_max;
  					_mixers->set_max_delta_out_once(delta_out_max);
  				}
  
  				if (_thr_mdl_fac > FLT_EPSILON) {
  					_mixers->set_thrust_factor(_thr_mdl_fac);
  				}
  
  				/* do mixing */
  				float outputs[_max_actuators];
  				size_t mixed_num_outputs = _mixers->mix(outputs, _num_outputs, NULL);
  
  				/* publish mixer status */
  				multirotor_motor_limits_s multirotor_motor_limits = {};
  				multirotor_motor_limits.saturation_status = _mixers->get_saturation_status();
  
  				if (_to_mixer_status == nullptr) {
  					/* publish limits */
  					int instance = _class_instance;
  					_to_mixer_status = orb_advertise_multi(ORB_ID(multirotor_motor_limits), &multirotor_motor_limits, &instance,
  									       ORB_PRIO_DEFAULT);
  
  				} else {
  					orb_publish(ORB_ID(multirotor_motor_limits), _to_mixer_status, &multirotor_motor_limits);
  
  				}
  
  				/* disable unused ports by setting their output to NaN */
  				for (size_t i = 0; i < sizeof(outputs) / sizeof(outputs[0]); i++) {
  					if (i >= mixed_num_outputs) {
  						outputs[i] = NAN_VALUE;
  					}
  				}
  
  				uint16_t pwm_limited[_max_actuators];
  
  				/* the PWM limit call takes care of out of band errors, NaN and constrains */
  				pwm_limit_calc(_throttle_armed, arm_nothrottle(), mixed_num_outputs, _reverse_pwm_mask,
  					       _disarmed_pwm, _min_pwm, _max_pwm, outputs, pwm_limited, &_pwm_limit);
  
  
  				/* overwrite outputs in case of force_failsafe with _failsafe_pwm PWM values */
  				if (_armed.force_failsafe) {
  					for (size_t i = 0; i < mixed_num_outputs; i++) {
  						pwm_limited[i] = _failsafe_pwm[i];
  					}
  				}
  
  				/* overwrite outputs in case of lockdown with disarmed PWM values */
  				if (_armed.lockdown || _armed.manual_lockdown) {
  					for (size_t i = 0; i < mixed_num_outputs; i++) {
  						pwm_limited[i] = _disarmed_pwm[i];
  					}
  				}
  
  				/* output to the servos */
  				for (size_t i = 0; i < mixed_num_outputs; i++) {
  					pwm_output_set(i, pwm_limited[i]);
  				}
  
  				/* Trigger all timer's channels in Oneshot mode to fire
  				 * the oneshots with updated values.
  				 */
  
  				if (n_updates > 0) {
  					up_pwm_update();
  				}
  
  				publish_pwm_outputs(pwm_limited, mixed_num_outputs);
  				perf_end(_ctl_latency);
  			}
  		}
  
  		_cycle_timestamp = hrt_absolute_time();
  
  #ifdef GPIO_BTN_SAFETY
  
  		if (_cycle_timestamp - _last_safety_check >= (unsigned int)1e5) {
  			_last_safety_check = _cycle_timestamp;
  
  			/**
  			 * Get and handle the safety status at 10Hz
  			 */
  			struct safety_s safety = {};
  
  			if (_safety_disabled) {
  				_safety_off = true;
  
  			} else {
  				/* read safety switch input and control safety switch LED at 10Hz */
  				safety_check_button();
  			}
  
  			/* Make the safety button flash anyway, no matter if it's used or not. */
  			flash_safety_button();
  
  			safety.timestamp = hrt_absolute_time();
  
  			if (_safety_off) {
  				safety.safety_off = true;
  				safety.safety_switch_available = true;
  
  			} else {
  				safety.safety_off = false;
  				safety.safety_switch_available = true;
  			}
  
  			/* lazily publish the safety status */
  			if (_to_safety != nullptr) {
  				orb_publish(ORB_ID(safety), _to_safety, &safety);
  
  			} else {
  				int instance = _class_instance;
  				_to_safety = orb_advertise_multi(ORB_ID(safety), &safety, &instance, ORB_PRIO_DEFAULT);
  			}
  		}
  
  #endif
  		/* check arming state */
  		bool updated = false;
  		orb_check(_armed_sub, &updated);
  
  		if (updated) {
  			orb_copy(ORB_ID(actuator_armed), _armed_sub, &_armed);
  
  			/* Update the armed status and check that we're not locked down.
  			 * We also need to arm throttle for the ESC calibration. */
  			_throttle_armed = (_safety_off && _armed.armed && !_armed.lockdown) ||
  					  (_safety_off && _armed.in_esc_calibration_mode);
  
  
  			/* update PWM status if armed or if disarmed PWM values are set */
  			bool pwm_on = _armed.armed || _num_disarmed_set > 0 || _armed.in_esc_calibration_mode;
  
  			if (_pwm_on != pwm_on) {
  				_pwm_on = pwm_on;
  
  				update_pwm_out_state(pwm_on);
  			}
  		}
  
  #ifdef RC_SERIAL_PORT
  		/* vehicle command */
  		orb_check(_vehicle_cmd_sub, &updated);
  
  		if (updated) {
  			struct vehicle_command_s cmd;
  			orb_copy(ORB_ID(vehicle_command), _vehicle_cmd_sub, &cmd);
  
  			// Check for a DSM pairing command
  			if (((unsigned int)cmd.command == vehicle_command_s::VEHICLE_CMD_START_RX_PAIR) && ((int)cmd.param1 == 0)) {
  				dsm_bind_ioctl((int)cmd.param2);
  			}
  
  		}
  
  #endif
  
  		orb_check(_param_sub, &updated);
  
  		if (updated) {
  			this->update_params();
  		}
  
  		/* update ADC sampling */
  #ifdef ADC_RC_RSSI_CHANNEL
  		orb_check(_adc_sub, &updated);
  
  		if (updated) {
  
  			struct adc_report_s adc;
  			orb_copy(ORB_ID(adc_report), _adc_sub, &adc);
  			const unsigned adc_chans = sizeof(adc.channel_id) / sizeof(adc.channel_id[0]);
  
  			for (unsigned i = 0; i < adc_chans; i++) {
  				if (adc.channel_id[i] == ADC_RC_RSSI_CHANNEL) {
  
  					if (_analog_rc_rssi_volt < 0.0f) {
  						_analog_rc_rssi_volt = adc.channel_value[i];
  					}
  
  					_analog_rc_rssi_volt = _analog_rc_rssi_volt * 0.995f + adc.channel_value[i] * 0.005f;
  
  					/* only allow this to be used if we see a high RSSI once */
  					if (_analog_rc_rssi_volt > 2.5f) {
  						_analog_rc_rssi_stable = true;
  					}
  				}
  			}
  		}
  
  #endif
  
  		bool rc_updated = false;
  
  #ifdef RC_SERIAL_PORT
  		// This block scans for a supported serial RC input and locks onto the first one found
  		// Scan for 300 msec, then switch protocol
  		constexpr hrt_abstime rc_scan_max = 300 * 1000;
  
  		bool sbus_failsafe, sbus_frame_drop;
  		unsigned frame_drops;
  		bool dsm_11_bit;
  
  
  		if (_report_lock && _rc_scan_locked) {
  			_report_lock = false;
  			//PX4_WARN("RCscan: %s RC input locked", RC_SCAN_STRING[_rc_scan_state]);
  		}
  
  		// read all available data from the serial RC input UART
  		int newBytes = ::read(_rcs_fd, &_rcs_buf[0], SBUS_BUFFER_SIZE);
  
  		switch (_rc_scan_state) {
  		case RC_SCAN_SBUS:
  			if (_rc_scan_begin == 0) {
  				_rc_scan_begin = _cycle_timestamp;
  				// Configure serial port for SBUS
  				sbus_config(_rcs_fd, false);
  				rc_io_invert(true);
  
  			} else if (_rc_scan_locked
  				   || _cycle_timestamp - _rc_scan_begin < rc_scan_max) {
  
  				// parse new data
  				if (newBytes > 0) {
  					rc_updated = sbus_parse(_cycle_timestamp, &_rcs_buf[0], newBytes, &raw_rc_values[0], &raw_rc_count, &sbus_failsafe,
  								&sbus_frame_drop, &frame_drops, input_rc_s::RC_INPUT_MAX_CHANNELS);
  
  					if (rc_updated) {
  						// we have a new SBUS frame. Publish it.
  						_rc_in.input_source = input_rc_s::RC_INPUT_SOURCE_PX4FMU_SBUS;
  						fill_rc_in(raw_rc_count, raw_rc_values, _cycle_timestamp,
  							   sbus_frame_drop, sbus_failsafe, frame_drops);
  						_rc_scan_locked = true;
  					}
  				}
  
  			} else {
  				// Scan the next protocol
  				set_rc_scan_state(RC_SCAN_DSM);
  			}
  
  			break;
  
  		case RC_SCAN_DSM:
  			if (_rc_scan_begin == 0) {
  				_rc_scan_begin = _cycle_timestamp;
  				//			// Configure serial port for DSM
  				dsm_config(_rcs_fd);
  				rc_io_invert(false);
  
  			} else if (_rc_scan_locked
  				   || _cycle_timestamp - _rc_scan_begin < rc_scan_max) {
  
  				if (newBytes > 0) {
  					// parse new data
  					rc_updated = dsm_parse(_cycle_timestamp, &_rcs_buf[0], newBytes, &raw_rc_values[0], &raw_rc_count,
  							       &dsm_11_bit, &frame_drops, input_rc_s::RC_INPUT_MAX_CHANNELS);
  
  					if (rc_updated) {
  						// we have a new DSM frame. Publish it.
  						_rc_in.input_source = input_rc_s::RC_INPUT_SOURCE_PX4FMU_DSM;
  						fill_rc_in(raw_rc_count, raw_rc_values, _cycle_timestamp,
  							   false, false, frame_drops);
  						_rc_scan_locked = true;
  					}
  				}
  
  			} else {
  				// Scan the next protocol
  				set_rc_scan_state(RC_SCAN_ST24);
  			}
  
  			break;
  
  		case RC_SCAN_ST24:
  			if (_rc_scan_begin == 0) {
  				_rc_scan_begin = _cycle_timestamp;
  				// Configure serial port for DSM
  				dsm_config(_rcs_fd);
  				rc_io_invert(false);
  
  			} else if (_rc_scan_locked
  				   || _cycle_timestamp - _rc_scan_begin < rc_scan_max) {
  
  				if (newBytes > 0) {
  					// parse new data
  					uint8_t st24_rssi, lost_count;
  
  					rc_updated = false;
  
  					for (unsigned i = 0; i < (unsigned)newBytes; i++) {
  						/* set updated flag if one complete packet was parsed */
  						st24_rssi = RC_INPUT_RSSI_MAX;
  						rc_updated = (OK == st24_decode(_rcs_buf[i], &st24_rssi, &lost_count,
  										&raw_rc_count, raw_rc_values, input_rc_s::RC_INPUT_MAX_CHANNELS));
  					}
  
  					// The st24 will keep outputting RC channels and RSSI even if RC has been lost.
  					// The only way to detect RC loss is therefore to look at the lost_count.
  
  					if (rc_updated && lost_count == 0) {
  						// we have a new ST24 frame. Publish it.
  						_rc_in.input_source = input_rc_s::RC_INPUT_SOURCE_PX4FMU_ST24;
  						fill_rc_in(raw_rc_count, raw_rc_values, _cycle_timestamp,
  							   false, false, frame_drops, st24_rssi);
  						_rc_scan_locked = true;
  					}
  				}
  
  			} else {
  				// Scan the next protocol
  				set_rc_scan_state(RC_SCAN_SUMD);
  			}
  
  			break;
  
  		case RC_SCAN_SUMD:
  			if (_rc_scan_begin == 0) {
  				_rc_scan_begin = _cycle_timestamp;
  				// Configure serial port for DSM
  				dsm_config(_rcs_fd);
  				rc_io_invert(false);
  
  			} else if (_rc_scan_locked
  				   || _cycle_timestamp - _rc_scan_begin < rc_scan_max) {
  
  				if (newBytes > 0) {
  					// parse new data
  					uint8_t sumd_rssi, rx_count;
  					bool sumd_failsafe;
  
  					rc_updated = false;
  
  					for (unsigned i = 0; i < (unsigned)newBytes; i++) {
  						/* set updated flag if one complete packet was parsed */
  						sumd_rssi = RC_INPUT_RSSI_MAX;
  						rc_updated = (OK == sumd_decode(_rcs_buf[i], &sumd_rssi, &rx_count,
  										&raw_rc_count, raw_rc_values, input_rc_s::RC_INPUT_MAX_CHANNELS, &sumd_failsafe));
  					}
  
  					if (rc_updated) {
  						// we have a new SUMD frame. Publish it.
  						_rc_in.input_source = input_rc_s::RC_INPUT_SOURCE_PX4FMU_SUMD;
  						fill_rc_in(raw_rc_count, raw_rc_values, _cycle_timestamp,
  							   false, sumd_failsafe, frame_drops, sumd_rssi);
  						_rc_scan_locked = true;
  					}
  				}
  
  			} else {
  				// Scan the next protocol
  				set_rc_scan_state(RC_SCAN_PPM);
  			}
  
  			break;
  
  		case RC_SCAN_PPM:
  			// skip PPM if it's not supported
  #ifdef HRT_PPM_CHANNEL
  			if (_rc_scan_begin == 0) {
  				_rc_scan_begin = _cycle_timestamp;
  				// Configure timer input pin for CPPM
  				px4_arch_configgpio(GPIO_PPM_IN);
  				rc_io_invert(false);
  
  			} else if (_rc_scan_locked
  				   || _cycle_timestamp - _rc_scan_begin < rc_scan_max) {
  
  				// see if we have new PPM input data
  				if ((ppm_last_valid_decode != _rc_in.timestamp_last_signal)
  				    && ppm_decoded_channels > 3) {
  					// we have a new PPM frame. Publish it.
  					rc_updated = true;
  					_rc_in.input_source = input_rc_s::RC_INPUT_SOURCE_PX4FMU_PPM;
  					fill_rc_in(ppm_decoded_channels, ppm_buffer, _cycle_timestamp,
  						   false, false, 0);
  					_rc_scan_locked = true;
  					_rc_in.rc_ppm_frame_length = ppm_frame_length;
  					_rc_in.timestamp_last_signal = ppm_last_valid_decode;
  				}
  
  			} else {
  				// disable CPPM input by mapping it away from the timer capture input
  				px4_arch_unconfiggpio(GPIO_PPM_IN);
  				// Scan the next protocol
  				set_rc_scan_state(RC_SCAN_SBUS);
  			}
  
  #else   // skip PPM if it's not supported
  			set_rc_scan_state(RC_SCAN_SBUS);
  
  #endif  // HRT_PPM_CHANNEL
  
  			break;
  		}
  
  #else  // RC_SERIAL_PORT not defined
  #ifdef HRT_PPM_CHANNEL
  
  		// see if we have new PPM input data
  		if ((ppm_last_valid_decode != _rc_in.timestamp_last_signal)
  		    && ppm_decoded_channels > 3) {
  			// we have a new PPM frame. Publish it.
  			rc_updated = true;
  			fill_rc_in(ppm_decoded_channels, ppm_buffer, hrt_absolute_time(),
  				   false, false, 0);
  		}
  
  #endif  // HRT_PPM_CHANNEL
  #endif  // RC_SERIAL_PORT
  
  		if (rc_updated) {
  			/* lazily advertise on first publication */
  			if (_to_input_rc == nullptr) {
  				int instance = _class_instance;
  				_to_input_rc = orb_advertise_multi(ORB_ID(input_rc), &_rc_in, &instance, ORB_PRIO_DEFAULT);
  
  			} else {
  				orb_publish(ORB_ID(input_rc), _to_input_rc, &_rc_in);
  			}
  
  		} else if (!rc_updated && ((hrt_absolute_time() - _rc_in.timestamp_last_signal) > 1000 * 1000)) {
  			_rc_scan_locked = false;
  		}
  
  		if (_run_as_task) {
  			if (should_exit()) {
  				break;
  			}
  
  		} else {
  			if (should_exit()) {
  				exit_and_cleanup();
  
  			} else {
  
  				/* schedule next cycle */
  				work_queue(HPWORK, &_work, (worker_t)&PX4FMU::cycle_trampoline, this, USEC2TICK(SCHEDULE_INTERVAL));
  				//																			  USEC2TICK(SCHEDULE_INTERVAL - main_out_latency));
  			}
  
  			break;
  		}
  	}
  }
  
  void PX4FMU::update_params()
  {
  	parameter_update_s pupdate;
  	orb_copy(ORB_ID(parameter_update), _param_sub, &pupdate);
  
  	update_pwm_rev_mask();
  	update_pwm_trims();
  
  	int32_t dsm_bind_val;
  	param_t param_handle;
  
  	/* see if bind parameter has been set, and reset it to -1 */
  	param_get(param_handle = param_find("RC_DSM_BIND"), &dsm_bind_val);
  
  	if (dsm_bind_val > -1) {
  		dsm_bind_ioctl(dsm_bind_val);
  		dsm_bind_val = -1;
  		param_set(param_handle, &dsm_bind_val);
  	}
  
  	// maximum motor slew rate parameter
  	param_handle = param_find("MOT_SLEW_MAX");
  
  	if (param_handle != PARAM_INVALID) {
  		param_get(param_handle, &_mot_t_max);
  	}
  
  	// thrust to pwm modelling factor
  	param_handle = param_find("THR_MDL_FAC");
  
  	if (param_handle != PARAM_INVALID) {
  		param_get(param_handle, &_thr_mdl_fac);
  	}
  }
  
  
  int
  PX4FMU::control_callback(uintptr_t handle,
  			 uint8_t control_group,
  			 uint8_t control_index,
  			 float &input)
  {
  	const actuator_controls_s *controls = (actuator_controls_s *)handle;
  
  	input = controls[control_group].control[control_index];
  
  	/* limit control input */
  	if (input > 1.0f) {
  		input = 1.0f;
  
  	} else if (input < -1.0f) {
  		input = -1.0f;
  	}
  
  	/* motor spinup phase - lock throttle to zero */
  	if (_pwm_limit.state == PWM_LIMIT_STATE_RAMP) {
  		if ((control_group == actuator_controls_s::GROUP_INDEX_ATTITUDE ||
  		     control_group == actuator_controls_s::GROUP_INDEX_ATTITUDE_ALTERNATE) &&
  		    control_index == actuator_controls_s::INDEX_THROTTLE) {
  			/* limit the throttle output to zero during motor spinup,
  			 * as the motors cannot follow any demand yet
  			 */
  			input = 0.0f;
  		}
  	}
  
  	/* throttle not arming - mark throttle input as invalid */
  	if (arm_nothrottle() && !_armed.in_esc_calibration_mode) {
  		if ((control_group == actuator_controls_s::GROUP_INDEX_ATTITUDE ||
  		     control_group == actuator_controls_s::GROUP_INDEX_ATTITUDE_ALTERNATE) &&
  		    control_index == actuator_controls_s::INDEX_THROTTLE) {
  			/* set the throttle to an invalid value */
  			input = NAN_VALUE;
  		}
  	}
  
  	return 0;
  }
  
  int
  PX4FMU::ioctl(file *filp, int cmd, unsigned long arg)
  {
  	int ret;
  
  	/* try it as a GPIO ioctl first */
  	ret = gpio_ioctl(filp, cmd, arg);
  
  	if (ret != -ENOTTY) {
  		return ret;
  	}
  
  	/* try it as a Capture ioctl next */
  	ret = capture_ioctl(filp, cmd, arg);
  
  	if (ret != -ENOTTY) {
  		return ret;
  	}
  
  	/* if we are in valid PWM mode, try it as a PWM ioctl as well */
  	switch (_mode) {
  	case MODE_1PWM:
  	case MODE_2PWM:
  	case MODE_3PWM:
  	case MODE_4PWM:
  	case MODE_2PWM2CAP:
  	case MODE_3PWM1CAP:
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 6
  	case MODE_6PWM:
  #endif
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 8
  	case MODE_8PWM:
  #endif
  		ret = pwm_ioctl(filp, cmd, arg);
  		break;
  
  	default:
  		PX4_DEBUG("not in a PWM mode");
  		break;
  	}
  
  	/* if nobody wants it, let CDev have it */
  	if (ret == -ENOTTY) {
  		ret = CDev::ioctl(filp, cmd, arg);
  	}
  
  	return ret;
  }
  
  int
  PX4FMU::pwm_ioctl(file *filp, int cmd, unsigned long arg)
  {
  	int ret = OK;
  
  	PX4_DEBUG("fmu ioctl cmd: %d, arg: %ld", cmd, arg);
  
  	lock();
  
  	switch (cmd) {
  	case PWM_SERVO_ARM:
  		update_pwm_out_state(true);
  		break;
  
  	case PWM_SERVO_SET_ARM_OK:
  	case PWM_SERVO_CLEAR_ARM_OK:
  		break;
  
  	case PWM_SERVO_SET_FORCE_SAFETY_OFF:
  		/* force safety switch off */
  		_safety_off = true;
  		break;
  
  	case PWM_SERVO_SET_FORCE_SAFETY_ON:
  		/* force safety switch on */
  		_safety_off = false;
  		break;
  
  	case PWM_SERVO_DISARM:
  
  		/* Ignore disarm if disarmed PWM is set already. */
  		if (_num_disarmed_set == 0) {
  			update_pwm_out_state(false);
  		}
  
  		break;
  
  	case PWM_SERVO_GET_DEFAULT_UPDATE_RATE:
  		*(uint32_t *)arg = _pwm_default_rate;
  		break;
  
  	case PWM_SERVO_SET_UPDATE_RATE:
  		ret = set_pwm_rate(_pwm_alt_rate_channels, _pwm_default_rate, arg);
  		break;
  
  	case PWM_SERVO_GET_UPDATE_RATE:
  		*(uint32_t *)arg = _pwm_alt_rate;
  		break;
  
  	case PWM_SERVO_SET_SELECT_UPDATE_RATE:
  		ret = set_pwm_rate(arg, _pwm_default_rate, _pwm_alt_rate);
  		break;
  
  	case PWM_SERVO_GET_SELECT_UPDATE_RATE:
  		*(uint32_t *)arg = _pwm_alt_rate_channels;
  		break;
  
  	case PWM_SERVO_SET_FAILSAFE_PWM: {
  			struct pwm_output_values *pwm = (struct pwm_output_values *)arg;
  
  			/* discard if too many values are sent */
  			if (pwm->channel_count > _max_actuators) {
  				ret = -EINVAL;
  				break;
  			}
  
  			for (unsigned i = 0; i < pwm->channel_count; i++) {
  				if (pwm->values[i] == 0) {
  					/* ignore 0 */
  				} else if (pwm->values[i] > PWM_HIGHEST_MAX) {
  					_failsafe_pwm[i] = PWM_HIGHEST_MAX;
  
  				}
  
  #if PWM_LOWEST_MIN > 0
  
  				else if (pwm->values[i] < PWM_LOWEST_MIN) {
  					_failsafe_pwm[i] = PWM_LOWEST_MIN;
  
  				}
  
  #endif
  
  				else {
  					_failsafe_pwm[i] = pwm->values[i];
  				}
  			}
  
  			/*
  			 * update the counter
  			 * this is needed to decide if disarmed PWM output should be turned on or not
  			 */
  			_num_failsafe_set = 0;
  
  			for (unsigned i = 0; i < _max_actuators; i++) {
  				if (_failsafe_pwm[i] > 0) {
  					_num_failsafe_set++;
  				}
  			}
  
  			break;
  		}
  
  	case PWM_SERVO_GET_FAILSAFE_PWM: {
  			struct pwm_output_values *pwm = (struct pwm_output_values *)arg;
  
  			for (unsigned i = 0; i < _max_actuators; i++) {
  				pwm->values[i] = _failsafe_pwm[i];
  			}
  
  			pwm->channel_count = _max_actuators;
  			break;
  		}
  
  	case PWM_SERVO_SET_DISARMED_PWM: {
  			struct pwm_output_values *pwm = (struct pwm_output_values *)arg;
  
  			/* discard if too many values are sent */
  			if (pwm->channel_count > _max_actuators) {
  				ret = -EINVAL;
  				break;
  			}
  
  			for (unsigned i = 0; i < pwm->channel_count; i++) {
  				if (pwm->values[i] == 0) {
  					/* ignore 0 */
  				} else if (pwm->values[i] > PWM_HIGHEST_MAX) {
  					_disarmed_pwm[i] = PWM_HIGHEST_MAX;
  				}
  
  #if PWM_LOWEST_MIN > 0
  
  				else if (pwm->values[i] < PWM_LOWEST_MIN) {
  					_disarmed_pwm[i] = PWM_LOWEST_MIN;
  				}
  
  #endif
  
  				else {
  					_disarmed_pwm[i] = pwm->values[i];
  				}
  			}
  
  			/*
  			 * update the counter
  			 * this is needed to decide if disarmed PWM output should be turned on or not
  			 */
  			_num_disarmed_set = 0;
  
  			for (unsigned i = 0; i < _max_actuators; i++) {
  				if (_disarmed_pwm[i] > 0) {
  					_num_disarmed_set++;
  				}
  			}
  
  			break;
  		}
  
  	case PWM_SERVO_GET_DISARMED_PWM: {
  			struct pwm_output_values *pwm = (struct pwm_output_values *)arg;
  
  			for (unsigned i = 0; i < _max_actuators; i++) {
  				pwm->values[i] = _disarmed_pwm[i];
  			}
  
  			pwm->channel_count = _max_actuators;
  			break;
  		}
  
  	case PWM_SERVO_SET_MIN_PWM: {
  			struct pwm_output_values *pwm = (struct pwm_output_values *)arg;
  
  			/* discard if too many values are sent */
  			if (pwm->channel_count > _max_actuators) {
  				ret = -EINVAL;
  				break;
  			}
  
  			for (unsigned i = 0; i < pwm->channel_count; i++) {
  				if (pwm->values[i] == 0) {
  					/* ignore 0 */
  				} else if (pwm->values[i] > PWM_HIGHEST_MIN) {
  					_min_pwm[i] = PWM_HIGHEST_MIN;
  
  				}
  
  #if PWM_LOWEST_MIN > 0
  
  				else if (pwm->values[i] < PWM_LOWEST_MIN) {
  					_min_pwm[i] = PWM_LOWEST_MIN;
  				}
  
  #endif
  
  				else {
  					_min_pwm[i] = pwm->values[i];
  				}
  			}
  
  			break;
  		}
  
  	case PWM_SERVO_GET_MIN_PWM: {
  			struct pwm_output_values *pwm = (struct pwm_output_values *)arg;
  
  			for (unsigned i = 0; i < _max_actuators; i++) {
  				pwm->values[i] = _min_pwm[i];
  			}
  
  			pwm->channel_count = _max_actuators;
  			arg = (unsigned long)&pwm;
  			break;
  		}
  
  	case PWM_SERVO_SET_MAX_PWM: {
  			struct pwm_output_values *pwm = (struct pwm_output_values *)arg;
  
  			/* discard if too many values are sent */
  			if (pwm->channel_count > _max_actuators) {
  				ret = -EINVAL;
  				break;
  			}
  
  			for (unsigned i = 0; i < pwm->channel_count; i++) {
  				if (pwm->values[i] == 0) {
  					/* ignore 0 */
  				} else if (pwm->values[i] < PWM_LOWEST_MAX) {
  					_max_pwm[i] = PWM_LOWEST_MAX;
  
  				} else if (pwm->values[i] > PWM_HIGHEST_MAX) {
  					_max_pwm[i] = PWM_HIGHEST_MAX;
  
  				} else {
  					_max_pwm[i] = pwm->values[i];
  				}
  			}
  
  			break;
  		}
  
  	case PWM_SERVO_GET_MAX_PWM: {
  			struct pwm_output_values *pwm = (struct pwm_output_values *)arg;
  
  			for (unsigned i = 0; i < _max_actuators; i++) {
  				pwm->values[i] = _max_pwm[i];
  			}
  
  			pwm->channel_count = _max_actuators;
  			arg = (unsigned long)&pwm;
  			break;
  		}
  
  	case PWM_SERVO_SET_TRIM_PWM: {
  			struct pwm_output_values *pwm = (struct pwm_output_values *)arg;
  
  			/* discard if too many values are sent */
  			if (pwm->channel_count > _max_actuators) {
  				PX4_DEBUG("error: too many trim values: %d", pwm->channel_count);
  				ret = -EINVAL;
  				break;
  			}
  
  			/* copy the trim values to the mixer offsets */
  			_mixers->set_trims((int16_t *)pwm->values, pwm->channel_count);
  			PX4_DEBUG("set_trims: %d, %d, %d, %d", pwm->values[0], pwm->values[1], pwm->values[2], pwm->values[3]);
  
  			break;
  		}
  
  	case PWM_SERVO_GET_TRIM_PWM: {
  			struct pwm_output_values *pwm = (struct pwm_output_values *)arg;
  
  			for (unsigned i = 0; i < _max_actuators; i++) {
  				pwm->values[i] = _trim_pwm[i];
  			}
  
  			pwm->channel_count = _max_actuators;
  			arg = (unsigned long)&pwm;
  			break;
  		}
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 8
  
  	case PWM_SERVO_SET(7):
  
  	/* FALLTHROUGH */
  	case PWM_SERVO_SET(6):
  		if (_mode < MODE_8PWM) {
  			ret = -EINVAL;
  			break;
  		}
  
  #endif
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 6
  
  	/* FALLTHROUGH */
  	case PWM_SERVO_SET(5):
  
  	/* FALLTHROUGH */
  	case PWM_SERVO_SET(4):
  		if (_mode < MODE_6PWM) {
  			ret = -EINVAL;
  			break;
  		}
  
  #endif
  
  	/* FALLTHROUGH */
  	case PWM_SERVO_SET(3):
  		if (_mode < MODE_4PWM) {
  			ret = -EINVAL;
  			break;
  		}
  
  	/* FALLTHROUGH */
  	case PWM_SERVO_SET(2):
  		if (_mode < MODE_3PWM) {
  			ret = -EINVAL;
  			break;
  		}
  
  	/* FALLTHROUGH */
  	case PWM_SERVO_SET(1):
  	case PWM_SERVO_SET(0):
  		if (arg <= 2100) {
  			up_pwm_servo_set(cmd - PWM_SERVO_SET(0), arg);
  
  		} else {
  			ret = -EINVAL;
  		}
  
  		break;
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 8
  
  	/* FALLTHROUGH */
  	case PWM_SERVO_GET(7):
  	case PWM_SERVO_GET(6):
  		if (_mode < MODE_8PWM) {
  			ret = -EINVAL;
  			break;
  		}
  
  #endif
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 6
  
  	/* FALLTHROUGH */
  	case PWM_SERVO_GET(5):
  	case PWM_SERVO_GET(4):
  		if (_mode < MODE_6PWM) {
  			ret = -EINVAL;
  			break;
  		}
  
  #endif
  
  	/* FALLTHROUGH */
  	case PWM_SERVO_GET(3):
  		if (_mode < MODE_4PWM) {
  			ret = -EINVAL;
  			break;
  		}
  
  	/* FALLTHROUGH */
  	case PWM_SERVO_GET(2):
  		if (_mode < MODE_3PWM) {
  			ret = -EINVAL;
  			break;
  		}
  
  	/* FALLTHROUGH */
  	case PWM_SERVO_GET(1):
  	case PWM_SERVO_GET(0):
  		*(servo_position_t *)arg = up_pwm_servo_get(cmd - PWM_SERVO_GET(0));
  		break;
  
  	case PWM_SERVO_GET_RATEGROUP(0):
  	case PWM_SERVO_GET_RATEGROUP(1):
  	case PWM_SERVO_GET_RATEGROUP(2):
  	case PWM_SERVO_GET_RATEGROUP(3):
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 6
  	case PWM_SERVO_GET_RATEGROUP(4):
  	case PWM_SERVO_GET_RATEGROUP(5):
  #endif
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 8
  	case PWM_SERVO_GET_RATEGROUP(6):
  	case PWM_SERVO_GET_RATEGROUP(7):
  #endif
  		*(uint32_t *)arg = up_pwm_servo_get_rate_group(cmd - PWM_SERVO_GET_RATEGROUP(0));
  		break;
  
  	case PWM_SERVO_GET_COUNT:
  	case MIXERIOCGETOUTPUTCOUNT:
  		switch (_mode) {
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 8
  
  		case MODE_8PWM:
  			*(unsigned *)arg = 8;
  			break;
  #endif
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 6
  
  		case MODE_6PWM:
  			*(unsigned *)arg = 6;
  			break;
  #endif
  
  		case MODE_4PWM:
  			*(unsigned *)arg = 4;
  			break;
  
  		case MODE_3PWM:
  		case MODE_3PWM1CAP:
  			*(unsigned *)arg = 3;
  			break;
  
  		case MODE_2PWM:
  		case MODE_2PWM2CAP:
  			*(unsigned *)arg = 2;
  			break;
  
  		case MODE_1PWM:
  			*(unsigned *)arg = 1;
  			break;
  
  		default:
  			ret = -EINVAL;
  			break;
  		}
  
  		break;
  
  	case PWM_SERVO_SET_COUNT: {
  			/* change the number of outputs that are enabled for
  			 * PWM. This is used to change the split between GPIO
  			 * and PWM under control of the flight config
  			 * parameters. Note that this does not allow for
  			 * changing a set of pins to be used for serial on
  			 * FMUv1
  			 */
  			switch (arg) {
  			case 0:
  				set_mode(MODE_NONE);
  				break;
  
  			case 1:
  				set_mode(MODE_1PWM);
  				break;
  
  			case 2:
  				set_mode(MODE_2PWM);
  				break;
  
  			case 3:
  				set_mode(MODE_3PWM);
  				break;
  
  			case 4:
  				set_mode(MODE_4PWM);
  				break;
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >=6
  
  			case 6:
  				set_mode(MODE_6PWM);
  				break;
  #endif
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >=8
  
  			case 8:
  				set_mode(MODE_8PWM);
  				break;
  #endif
  
  			default:
  				ret = -EINVAL;
  				break;
  			}
  
  			break;
  		}
  
  	case PWM_SERVO_SET_MODE: {
  			switch (arg) {
  			case PWM_SERVO_MODE_NONE:
  				ret = set_mode(MODE_NONE);
  				break;
  
  			case PWM_SERVO_MODE_1PWM:
  				ret = set_mode(MODE_1PWM);
  				break;
  
  			case PWM_SERVO_MODE_2PWM:
  				ret = set_mode(MODE_2PWM);
  				break;
  
  			case PWM_SERVO_MODE_2PWM2CAP:
  				ret = set_mode(MODE_2PWM2CAP);
  				break;
  
  			case PWM_SERVO_MODE_3PWM:
  				ret = set_mode(MODE_3PWM);
  				break;
  
  			case PWM_SERVO_MODE_3PWM1CAP:
  				ret = set_mode(MODE_3PWM1CAP);
  				break;
  
  			case PWM_SERVO_MODE_4PWM:
  				ret = set_mode(MODE_4PWM);
  				break;
  
  			case PWM_SERVO_MODE_6PWM:
  				ret = set_mode(MODE_6PWM);
  				break;
  
  			case PWM_SERVO_MODE_8PWM:
  				ret = set_mode(MODE_8PWM);
  				break;
  
  			case PWM_SERVO_MODE_4CAP:
  				ret = set_mode(MODE_4CAP);
  				break;
  
  			case PWM_SERVO_MODE_5CAP:
  				ret = set_mode(MODE_5CAP);
  				break;
  
  			case PWM_SERVO_MODE_6CAP:
  				ret = set_mode(MODE_6CAP);
  				break;
  
  			default:
  				ret = -EINVAL;
  			}
  
  			break;
  		}
  
  #ifdef SPEKTRUM_POWER
  
  	case DSM_BIND_START:
  		/* only allow DSM2, DSM-X and DSM-X with more than 7 channels */
  		PX4_INFO("pwm_ioctl: DSM_BIND_START, arg: %lu", arg);
  
  		if (arg == DSM2_BIND_PULSES ||
  		    arg == DSMX_BIND_PULSES ||
  		    arg == DSMX8_BIND_PULSES) {
  
  			dsm_bind(DSM_CMD_BIND_POWER_DOWN, 0);
  
  			dsm_bind(DSM_CMD_BIND_SET_RX_OUT, 0);
  			usleep(500000);
  
  			dsm_bind(DSM_CMD_BIND_POWER_UP, 0);
  			usleep(72000);
  
  			irqstate_t flags = px4_enter_critical_section();
  			dsm_bind(DSM_CMD_BIND_SEND_PULSES, arg);
  			px4_leave_critical_section(flags);
  			usleep(50000);
  
  			dsm_bind(DSM_CMD_BIND_REINIT_UART, 0);
  
  			ret = OK;
  
  		} else {
  			ret = -EINVAL;
  		}
  
  		break;
  #endif
  
  	case MIXERIOCRESET:
  		if (_mixers != nullptr) {
  			delete _mixers;
  			_mixers = nullptr;
  			_groups_required = 0;
  		}
  
  		break;
  
  	case MIXERIOCADDSIMPLE: {
  			mixer_simple_s *mixinfo = (mixer_simple_s *)arg;
  
  			SimpleMixer *mixer = new SimpleMixer(control_callback,
  							     (uintptr_t)_controls, mixinfo);
  
  			if (mixer->check()) {
  				delete mixer;
  				_groups_required = 0;
  				ret = -EINVAL;
  
  			} else {
  				if (_mixers == nullptr)
  					_mixers = new MixerGroup(control_callback,
  								 (uintptr_t)_controls);
  
  				_mixers->add_mixer(mixer);
  				_mixers->groups_required(_groups_required);
  			}
  
  			break;
  		}
  
  	case MIXERIOCLOADBUF: {
  			const char *buf = (const char *)arg;
  			unsigned buflen = strnlen(buf, 1024);
  
  			if (_mixers == nullptr) {
  				_mixers = new MixerGroup(control_callback, (uintptr_t)_controls);
  			}
  
  			if (_mixers == nullptr) {
  				_groups_required = 0;
  				ret = -ENOMEM;
  
  			} else {
  
  				ret = _mixers->load_from_buf(buf, buflen);
  
  				if (ret != 0) {
  					PX4_DEBUG("mixer load failed with %d", ret);
  					delete _mixers;
  					_mixers = nullptr;
  					_groups_required = 0;
  					ret = -EINVAL;
  
  				} else {
  
  					_mixers->groups_required(_groups_required);
  					PX4_DEBUG("loaded mixers \n%s\n", buf);
  					update_pwm_trims();
  				}
  			}
  
  			break;
  		}
  
  	default:
  		ret = -ENOTTY;
  		break;
  	}
  
  	unlock();
  
  	return ret;
  }
  
  /*
    this implements PWM output via a write() method, for compatibility
    with px4io
   */
  ssize_t
  PX4FMU::write(file *filp, const char *buffer, size_t len)
  {
  	unsigned count = len / 2;
  	uint16_t values[8];
  
  #if BOARD_HAS_PWM == 0
  	return 0;
  #endif
  
  	if (count > BOARD_HAS_PWM) {
  		// we have at most BOARD_HAS_PWM outputs
  		count = BOARD_HAS_PWM;
  	}
  
  	// allow for misaligned values
  	memcpy(values, buffer, count * 2);
  
  	for (uint8_t i = 0; i < count; i++) {
  		if (values[i] != PWM_IGNORE_THIS_CHANNEL) {
  			up_pwm_servo_set(i, values[i]);
  		}
  	}
  
  	return count * 2;
  }
  
  void
  PX4FMU::sensor_reset(int ms)
  {
  	if (ms < 1) {
  		ms = 1;
  	}
  
  	board_spi_reset(ms);
  }
  
  void
  PX4FMU::peripheral_reset(int ms)
  {
  	if (ms < 1) {
  		ms = 10;
  	}
  
  	board_peripheral_reset(ms);
  }
  
  int
  PX4FMU::gpio_reset(void)
  {
  #if !defined(BOARD_HAS_FMU_GPIO)
  	return -EINVAL;
  #else
  
  	/*
  	 * Setup default GPIO config - all pins as GPIOs, input if
  	 * possible otherwise output if possible.
  	 */
  	for (unsigned i = 0; i < _ngpio; i++) {
  		if (_gpio_tab[i].input != 0) {
  			px4_arch_configgpio(_gpio_tab[i].input);
  
  		} else if (_gpio_tab[i].output != 0) {
  			px4_arch_configgpio(_gpio_tab[i].output);
  		}
  	}
  
  #  if defined(GPIO_GPIO_DIR)
  	/* if we have a GPIO direction control, set it to zero (input) */
  	px4_arch_gpiowrite(GPIO_GPIO_DIR, 0);
  	px4_arch_configgpio(GPIO_GPIO_DIR);
  #  endif
  	return OK;
  #endif // !defined(BOARD_HAS_FMU_GPIO)
  }
  
  int
  PX4FMU::gpio_set_function(uint32_t gpios, int function)
  {
  #if !defined(BOARD_HAS_FMU_GPIO)
  	return -EINVAL;
  #else
  #  if defined(BOARD_GPIO_SHARED_BUFFERED_BITS) && defined(GPIO_GPIO_DIR)
  
  	/*
  	 * GPIOs 0 and 1 must have the same direction as they are buffered
  	 * by a shared 2-port driver.  Any attempt to set either sets both.
  	 */
  	if ((gpios & BOARD_GPIO_SHARED_BUFFERED_BITS)) {
  		gpios |= BOARD_GPIO_SHARED_BUFFERED_BITS;
  
  		/* flip the buffer to output mode if required */
  		if (GPIO_SET_OUTPUT == function ||
  		    GPIO_SET_OUTPUT_LOW == function ||
  		    GPIO_SET_OUTPUT_HIGH == function) {
  			px4_arch_gpiowrite(GPIO_GPIO_DIR, 1);
  		}
  	}
  
  #  endif
  
  	/* configure selected GPIOs as required */
  	for (unsigned i = 0; i < _ngpio; i++) {
  		if (gpios & (1 << i)) {
  			switch (function) {
  			case GPIO_SET_INPUT:
  				if (_gpio_tab[i].input) {
  					px4_arch_configgpio(_gpio_tab[i].input);
  				}
  
  				break;
  
  			case GPIO_SET_OUTPUT:
  				if (_gpio_tab[i].output) {
  					px4_arch_configgpio(_gpio_tab[i].output);
  				}
  
  				break;
  
  			case GPIO_SET_OUTPUT_LOW:
  				if (_gpio_tab[i].output) {
  					px4_arch_configgpio((_gpio_tab[i].output & ~(GPIO_OUTPUT_SET)) | GPIO_OUTPUT_CLEAR);
  				}
  
  				break;
  
  			case GPIO_SET_OUTPUT_HIGH:
  				if (_gpio_tab[i].output) {
  					px4_arch_configgpio((_gpio_tab[i].output & ~(GPIO_OUTPUT_CLEAR)) | GPIO_OUTPUT_SET);
  				}
  
  				break;
  
  			case GPIO_SET_ALT_1:
  				if (_gpio_tab[i].alt != 0) {
  					px4_arch_configgpio(_gpio_tab[i].alt);
  				}
  
  				break;
  			}
  		}
  	}
  
  #  if defined(BOARD_GPIO_SHARED_BUFFERED_BITS) && defined(GPIO_GPIO_DIR)
  
  	/* flip buffer to input mode if required */
  	if ((GPIO_SET_INPUT == function) && (gpios & BOARD_GPIO_SHARED_BUFFERED_BITS)) {
  		px4_arch_gpiowrite(GPIO_GPIO_DIR, 0);
  	}
  
  #  endif
  	return OK;
  #endif // !defined(BOARD_HAS_FMU_GPIO)
  
  }
  
  int
  PX4FMU::gpio_write(uint32_t gpios, int function)
  {
  #if !defined(BOARD_HAS_FMU_GPIO)
  	return -EINVAL;
  #else
  	int value = (function == GPIO_SET) ? 1 : 0;
  
  	for (unsigned i = 0; i < _ngpio; i++) {
  		if (gpios & (1 << i)) {
  			if (_gpio_tab[i].output) {
  				px4_arch_gpiowrite(_gpio_tab[i].output, value);
  			}
  		}
  	}
  
  	return OK;
  #endif
  }
  
  int
  PX4FMU::gpio_read(uint32_t *value)
  {
  #if !defined(BOARD_HAS_FMU_GPIO)
  	return -EINVAL;
  #else
  	uint32_t bits = 0;
  
  	for (unsigned i = 0; i < _ngpio; i++) {
  		if (_gpio_tab[i].input != 0 && px4_arch_gpioread(_gpio_tab[i].input)) {
  			bits |= (1 << i);
  		}
  	}
  
  	*value = bits;
  	return OK;
  #endif
  }
  
  int
  PX4FMU::capture_ioctl(struct file *filp, int cmd, unsigned long arg)
  {
  	int	ret = -EINVAL;
  
  #if defined(BOARD_HAS_CAPTURE)
  
  	lock();
  
  	input_capture_config_t *pconfig = 0;
  
  	input_capture_stats_t *stats = (input_capture_stats_t *)arg;
  
  	if (_mode == MODE_3PWM1CAP || _mode == MODE_2PWM2CAP) {
  
  		pconfig = (input_capture_config_t *)arg;
  	}
  
  	switch (cmd) {
  
  	case INPUT_CAP_SET:
  		if (pconfig) {
  			ret =  up_input_capture_set(pconfig->channel, pconfig->edge, pconfig->filter,
  						    pconfig->callback, pconfig->context);
  		}
  
  		break;
  
  	case INPUT_CAP_SET_CALLBACK:
  		if (pconfig) {
  			ret =  up_input_capture_set_callback(pconfig->channel, pconfig->callback, pconfig->context);
  		}
  
  		break;
  
  	case INPUT_CAP_GET_CALLBACK:
  		if (pconfig) {
  			ret =  up_input_capture_get_callback(pconfig->channel, &pconfig->callback, &pconfig->context);
  		}
  
  		break;
  
  	case INPUT_CAP_GET_STATS:
  		if (arg) {
  			ret =  up_input_capture_get_stats(stats->chan_in_edges_out, stats, false);
  		}
  
  		break;
  
  	case INPUT_CAP_GET_CLR_STATS:
  		if (arg) {
  			ret =  up_input_capture_get_stats(stats->chan_in_edges_out, stats, true);
  		}
  
  		break;
  
  	case INPUT_CAP_SET_EDGE:
  		if (pconfig) {
  			ret =  up_input_capture_set_trigger(pconfig->channel, pconfig->edge);
  		}
  
  		break;
  
  	case INPUT_CAP_GET_EDGE:
  		if (pconfig) {
  			ret =  up_input_capture_get_trigger(pconfig->channel, &pconfig->edge);
  		}
  
  		break;
  
  	case INPUT_CAP_SET_FILTER:
  		if (pconfig) {
  			ret =  up_input_capture_set_filter(pconfig->channel, pconfig->filter);
  		}
  
  		break;
  
  	case INPUT_CAP_GET_FILTER:
  		if (pconfig) {
  			ret =  up_input_capture_get_filter(pconfig->channel, &pconfig->filter);
  		}
  
  		break;
  
  	case INPUT_CAP_GET_COUNT:
  		ret = OK;
  
  		switch (_mode) {
  		case MODE_3PWM1CAP:
  			*(unsigned *)arg = 1;
  			break;
  
  		case MODE_2PWM2CAP:
  			*(unsigned *)arg = 2;
  			break;
  
  		default:
  			ret = -EINVAL;
  			break;
  		}
  
  		break;
  
  	case INPUT_CAP_SET_COUNT:
  		ret = OK;
  
  		switch (_mode) {
  		case MODE_3PWM1CAP:
  			set_mode(MODE_3PWM1CAP);
  			break;
  
  		case MODE_2PWM2CAP:
  			set_mode(MODE_2PWM2CAP);
  			break;
  
  		default:
  			ret = -EINVAL;
  			break;
  		}
  
  		break;
  
  	default:
  		ret = -ENOTTY;
  		break;
  	}
  
  	unlock();
  
  #else
  	ret = -ENOTTY;
  #endif
  	return ret;
  }
  
  int
  PX4FMU::gpio_ioctl(struct file *filp, int cmd, unsigned long arg)
  {
  	int	ret = OK;
  
  	lock();
  
  	switch (cmd) {
  
  	case GPIO_RESET:
  		ret = gpio_reset();
  		break;
  
  	case GPIO_SENSOR_RAIL_RESET:
  		sensor_reset(arg);
  		break;
  
  	case GPIO_PERIPHERAL_RAIL_RESET:
  		peripheral_reset(arg);
  		break;
  
  	case GPIO_SET_OUTPUT:
  	case GPIO_SET_OUTPUT_LOW:
  	case GPIO_SET_OUTPUT_HIGH:
  	case GPIO_SET_INPUT:
  	case GPIO_SET_ALT_1:
  		ret = gpio_set_function(arg, cmd);
  		break;
  
  	case GPIO_SET_ALT_2:
  	case GPIO_SET_ALT_3:
  	case GPIO_SET_ALT_4:
  		ret = -EINVAL;
  		break;
  
  	case GPIO_SET:
  	case GPIO_CLEAR:
  		ret = gpio_write(arg, cmd);
  		break;
  
  	case GPIO_GET:
  		ret = gpio_read((uint32_t *)arg);
  		break;
  
  	default:
  		ret = -ENOTTY;
  	}
  
  	unlock();
  
  	return ret;
  }
  
  void
  PX4FMU::dsm_bind_ioctl(int dsmMode)
  {
  	if (!_armed.armed) {
  //      mavlink_log_info(&_mavlink_log_pub, "[FMU] binding DSM%s RX", (dsmMode == 0) ? "2" : ((dsmMode == 1) ? "-X" : "-X8"));
  		PX4_INFO("[FMU] binding DSM%s RX", (dsmMode == 0) ? "2" : ((dsmMode == 1) ? "-X" : "-X8"));
  		int ret = ioctl(nullptr, DSM_BIND_START,
  				(dsmMode == 0) ? DSM2_BIND_PULSES : ((dsmMode == 1) ? DSMX_BIND_PULSES : DSMX8_BIND_PULSES));
  
  		if (ret) {
  //            mavlink_log_critical(&_mavlink_log_pub, "binding failed.");
  			PX4_ERR("binding failed.");
  		}
  
  	} else {
  //        mavlink_log_info(&_mavlink_log_pub, "[FMU] system armed, bind request rejected");
  		PX4_WARN("[FMU] system armed, bind request rejected");
  	}
  }
  
  int
  PX4FMU::fmu_new_mode(PortMode new_mode)
  {
  	if (!is_running()) {
  		return -1;
  	}
  
  	uint32_t gpio_bits;
  	PX4FMU::Mode servo_mode;
  	bool mode_with_input = false;
  
  	gpio_bits = 0;
  	servo_mode = PX4FMU::MODE_NONE;
  
  	switch (new_mode) {
  	case PORT_FULL_GPIO:
  	case PORT_MODE_UNSET:
  		break;
  
  	case PORT_FULL_PWM:
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM == 4
  		/* select 4-pin PWM mode */
  		servo_mode = PX4FMU::MODE_4PWM;
  #endif
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM == 6
  		servo_mode = PX4FMU::MODE_6PWM;
  #endif
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM == 8
  		servo_mode = PX4FMU::MODE_8PWM;
  #endif
  		break;
  
  	case PORT_RC_IN:
  		servo_mode = PX4FMU::MODE_NONE;
  		break;
  
  	case PORT_PWM1:
  		/* select 2-pin PWM mode */
  		servo_mode = PX4FMU::MODE_1PWM;
  		break;
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 6
  
  	case PORT_PWM4:
  		/* select 4-pin PWM mode */
  		servo_mode = PX4FMU::MODE_4PWM;
  		break;
  
  	case PORT_PWM3:
  		/* select 3-pin PWM mode */
  		servo_mode = PX4FMU::MODE_3PWM;
  		break;
  
  	case PORT_PWM3CAP1:
  		/* select 3-pin PWM mode 1 capture */
  		servo_mode = PX4FMU::MODE_3PWM1CAP;
  		mode_with_input = true;
  		break;
  
  	case PORT_PWM2:
  		/* select 2-pin PWM mode */
  		servo_mode = PX4FMU::MODE_2PWM;
  		break;
  
  	case PORT_PWM2CAP2:
  		/* select 2-pin PWM mode 2 capture */
  		servo_mode = PX4FMU::MODE_2PWM2CAP;
  		mode_with_input = true;
  		break;
  #endif
  
  		/* mixed modes supported on v1 board only */
  #if defined(BOARD_HAS_MULTI_PURPOSE_GPIO)
  
  	case PORT_FULL_SERIAL:
  		/* set all multi-GPIOs to serial mode */
  		gpio_bits = GPIO_MULTI_1 | GPIO_MULTI_2 | GPIO_MULTI_3 | GPIO_MULTI_4;
  		mode_with_input = true;
  		break;
  
  	case PORT_GPIO_AND_SERIAL:
  		/* set RX/TX multi-GPIOs to serial mode */
  		gpio_bits = GPIO_MULTI_3 | GPIO_MULTI_4;
  		mode_with_input = true;
  		break;
  
  	case PORT_PWM_AND_SERIAL:
  		/* select 2-pin PWM mode */
  		servo_mode = PX4FMU::MODE_2PWM;
  		/* set RX/TX multi-GPIOs to serial mode */
  		gpio_bits = GPIO_MULTI_3 | GPIO_MULTI_4;
  		mode_with_input = true;
  		break;
  
  	case PORT_PWM_AND_GPIO:
  		/* select 2-pin PWM mode */
  		servo_mode = PX4FMU::MODE_2PWM;
  		mode_with_input = true;
  		break;
  #endif
  
  	default:
  		return -1;
  	}
  
  	PX4FMU *object = get_instance();
  
  	if (servo_mode != object->get_mode()) {
  
  		/* reset to all-inputs */
  		if (mode_with_input) {
  			object->ioctl(0, GPIO_RESET, 0);
  
  			/* adjust GPIO config for serial mode(s) */
  			if (gpio_bits != 0) {
  				object->ioctl(0, GPIO_SET_ALT_1, gpio_bits);
  			}
  		}
  
  		/* (re)set the PWM output mode */
  		object->set_mode(servo_mode);
  	}
  
  	return OK;
  }
  
  
  namespace
  {
  
  void
  bind_spektrum()
  {
  	int	 fd;
  
  	fd = open(PX4FMU_DEVICE_PATH, O_RDWR);
  
  	if (fd < 0) {
  		PX4_ERR("open fail");
  		return;
  	}
  
  	PX4_INFO("bind_Spektrum RX");
  
  	/* specify 11ms DSMX. RX will automatically fall back to 22ms or DSM2 if necessary */
  	if (ioctl(fd, DSM_BIND_START, DSMX8_BIND_PULSES)) {
  		PX4_ERR("binding failed.");
  	}
  
  	close(fd);
  
  }
  
  int fmu_new_i2c_speed(unsigned bus, unsigned clock_hz)
  {
  	return PX4FMU::set_i2c_bus_clock(bus, clock_hz);
  }
  
  } // namespace
  
  int
  PX4FMU::test()
  {
  	int	 fd;
  	unsigned servo_count = 0;
  	unsigned capture_count = 0;
  	unsigned pwm_value = 1000;
  	int	 direction = 1;
  	int	 ret;
  	uint32_t rate_limit = 0;
  	struct input_capture_t {
  		bool valid;
  		input_capture_config_t  chan;
  	} capture_conf[INPUT_CAPTURE_MAX_CHANNELS];
  
  	fd = ::open(PX4FMU_DEVICE_PATH, O_RDWR);
  
  	if (fd < 0) {
  		PX4_ERR("open fail");
  		return -1;
  	}
  
  	if (::ioctl(fd, PWM_SERVO_ARM, 0) < 0) {
  		PX4_ERR("servo arm failed");
  		goto err_out;
  	}
  
  	if (::ioctl(fd, PWM_SERVO_GET_COUNT, (unsigned long)&servo_count) != 0) {
  		PX4_ERR("Unable to get servo count");
  		goto err_out;
  	}
  
  	if (::ioctl(fd, INPUT_CAP_GET_COUNT, (unsigned long)&capture_count) != 0) {
  		PX4_INFO("Not in a capture mode");
  	}
  
  	PX4_INFO("Testing %u servos and %u input captures", (unsigned)servo_count, capture_count);
  	memset(capture_conf, 0, sizeof(capture_conf));
  
  	if (capture_count != 0) {
  		for (unsigned i = 0; i < capture_count; i++) {
  			// Map to channel number
  			capture_conf[i].chan.channel = i + servo_count;
  
  			/* Save handler */
  			if (::ioctl(fd, INPUT_CAP_GET_CALLBACK, (unsigned long)&capture_conf[i].chan.channel) != 0) {
  				PX4_ERR("Unable to get capture callback for chan %u\n", capture_conf[i].chan.channel);
  				goto err_out;
  
  			} else {
  				input_capture_config_t conf = capture_conf[i].chan;
  				conf.callback = &PX4FMU::capture_trampoline;
  				conf.context = PX4FMU::get_instance();
  
  				if (::ioctl(fd, INPUT_CAP_SET_CALLBACK, (unsigned long)&conf) == 0) {
  					capture_conf[i].valid = true;
  
  				} else {
  					PX4_ERR("Unable to set capture callback for chan %u\n", capture_conf[i].chan.channel);
  					goto err_out;
  				}
  			}
  
  		}
  	}
  
  	struct pollfd fds;
  
  	fds.fd = 0; /* stdin */
  
  	fds.events = POLLIN;
  
  	PX4_INFO("Press CTRL-C or 'c' to abort.");
  
  	for (;;) {
  		/* sweep all servos between 1000..2000 */
  		servo_position_t servos[servo_count];
  
  		for (unsigned i = 0; i < servo_count; i++) {
  			servos[i] = pwm_value;
  		}
  
  		if (direction == 1) {
  			// use ioctl interface for one direction
  			for (unsigned i = 0; i < servo_count;	i++) {
  				if (::ioctl(fd, PWM_SERVO_SET(i), servos[i]) < 0) {
  					PX4_ERR("servo %u set failed", i);
  					goto err_out;
  				}
  			}
  
  		} else {
  			// and use write interface for the other direction
  			ret = ::write(fd, servos, sizeof(servos));
  
  			if (ret != (int)sizeof(servos)) {
  				PX4_ERR("error writing PWM servo data, wrote %u got %d", sizeof(servos), ret);
  				goto err_out;
  			}
  		}
  
  		if (direction > 0) {
  			if (pwm_value < 2000) {
  				pwm_value++;
  
  			} else {
  				direction = -1;
  			}
  
  		} else {
  			if (pwm_value > 1000) {
  				pwm_value--;
  
  			} else {
  				direction = 1;
  			}
  		}
  
  		/* readback servo values */
  		for (unsigned i = 0; i < servo_count; i++) {
  			servo_position_t value;
  
  			if (::ioctl(fd, PWM_SERVO_GET(i), (unsigned long)&value)) {
  				PX4_ERR("error reading PWM servo %d", i);
  				goto err_out;
  			}
  
  			if (value != servos[i]) {
  				PX4_ERR("servo %d readback error, got %u expected %u", i, value, servos[i]);
  				goto err_out;
  			}
  		}
  
  		if (capture_count != 0 && (++rate_limit % 500 == 0)) {
  			for (unsigned i = 0; i < capture_count; i++) {
  				if (capture_conf[i].valid) {
  					input_capture_stats_t stats;
  					stats.chan_in_edges_out = capture_conf[i].chan.channel;
  
  					if (::ioctl(fd, INPUT_CAP_GET_STATS, (unsigned long)&stats) != 0) {
  						PX4_ERR("Unable to get stats for chan %u\n", capture_conf[i].chan.channel);
  						goto err_out;
  
  					} else {
  						fprintf(stdout, "FMU: Status chan:%u edges: %d last time:%lld last state:%d overflows:%d lantency:%u\n",
  							capture_conf[i].chan.channel,
  							stats.chan_in_edges_out,
  							stats.last_time,
  							stats.last_edge,
  							stats.overflows,
  							stats.latnecy);
  					}
  				}
  			}
  
  		}
  
  		/* Check if user wants to quit */
  		char c;
  		ret = ::poll(&fds, 1, 0);
  
  		if (ret > 0) {
  
  			::read(0, &c, 1);
  
  			if (c == 0x03 || c == 0x63 || c == 'q') {
  				PX4_INFO("User abort");
  				break;
  			}
  		}
  	}
  
  	if (capture_count != 0) {
  		for (unsigned i = 0; i < capture_count; i++) {
  			// Map to channel number
  			if (capture_conf[i].valid) {
  				/* Save handler */
  				if (::ioctl(fd, INPUT_CAP_SET_CALLBACK, (unsigned long)&capture_conf[i].chan) != 0) {
  					PX4_ERR("Unable to set capture callback for chan %u\n", capture_conf[i].chan.channel);
  					goto err_out;
  				}
  			}
  		}
  	}
  
  	::close(fd);
  	return 0;
  
  err_out:
  	::close(fd);
  	return -1;
  }
  
  int
  PX4FMU::fake(int argc, char *argv[])
  {
  	if (argc < 5) {
  		print_usage("not enough arguments");
  		return -1;
  	}
  
  	actuator_controls_s ac;
  
  	ac.control[0] = strtol(argv[1], 0, 0) / 100.0f;
  
  	ac.control[1] = strtol(argv[2], 0, 0) / 100.0f;
  
  	ac.control[2] = strtol(argv[3], 0, 0) / 100.0f;
  
  	ac.control[3] = strtol(argv[4], 0, 0) / 100.0f;
  
  	orb_advert_t handle = orb_advertise(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, &ac);
  
  	if (handle == nullptr) {
  		PX4_ERR("advertise failed");
  		return -1;
  	}
  
  	orb_unadvertise(handle);
  
  	actuator_armed_s aa;
  
  	aa.armed = true;
  	aa.lockdown = false;
  
  	handle = orb_advertise(ORB_ID(actuator_armed), &aa);
  
  	if (handle == nullptr) {
  		PX4_ERR("advertise failed 2");
  		return -1;
  	}
  
  	orb_unadvertise(handle);
  	return 0;
  }
  
  PX4FMU *PX4FMU::instantiate(int argc, char *argv[])
  {
  	// No arguments to parse. We also know that we should run as task
  	return new PX4FMU(true);
  }
  
  int PX4FMU::custom_command(int argc, char *argv[])
  {
  	PortMode new_mode = PORT_MODE_UNSET;
  	const char *verb = argv[0];
  
  	if (!strcmp(verb, "bind")) {
  		bind_spektrum();
  		return 0;
  	}
  
  	/* does not operate on a FMU instance */
  	if (!strcmp(verb, "i2c")) {
  		if (argc > 2) {
  			int bus = strtol(argv[1], 0, 0);
  			int clock_hz = strtol(argv[2], 0, 0);
  			int ret = fmu_new_i2c_speed(bus, clock_hz);
  
  			if (ret) {
  				PX4_ERR("setting I2C clock failed");
  			}
  
  			return ret;
  		}
  
  		return print_usage("not enough arguments");
  	}
  
  	if (!strcmp(verb, "sensor_reset")) {
  		if (argc > 1) {
  			int reset_time = strtol(argv[1], nullptr, 0);
  			sensor_reset(reset_time);
  
  		} else {
  			sensor_reset(0);
  			PX4_INFO("reset default time");
  		}
  
  		return 0;
  	}
  
  	if (!strcmp(verb, "peripheral_reset")) {
  		if (argc > 2) {
  			int reset_time = strtol(argv[2], 0, 0);
  			peripheral_reset(reset_time);
  
  		} else {
  			peripheral_reset(0);
  			PX4_INFO("reset default time");
  		}
  
  		return 0;
  	}
  
  
  	/* start the FMU if not running */
  	if (!is_running()) {
  		int ret = PX4FMU::task_spawn(argc, argv);
  
  		if (ret) {
  			return ret;
  		}
  	}
  
  	/*
  	 * Mode switches.
  	 */
  	if (!strcmp(verb, "mode_gpio")) {
  		new_mode = PORT_FULL_GPIO;
  
  	} else if (!strcmp(verb, "mode_rcin")) {
  		new_mode = PORT_RC_IN;
  
  	} else if (!strcmp(verb, "mode_pwm")) {
  		new_mode = PORT_FULL_PWM;
  
  		// mode: defines which outputs to drive (others may be used by other tasks such as camera capture)
  #if defined(BOARD_HAS_PWM)
  
  	} else if (!strcmp(verb, "mode_pwm1")) {
  		new_mode = PORT_PWM1;
  #endif
  
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 6
  
  
  	} else if (!strcmp(verb, "mode_pwm4")) {
  		new_mode = PORT_PWM4;
  
  	} else if (!strcmp(verb, "mode_pwm2")) {
  		new_mode = PORT_PWM2;
  
  	} else if (!strcmp(verb, "mode_pwm3")) {
  		new_mode = PORT_PWM3;
  
  	} else if (!strcmp(verb, "mode_pwm3cap1")) {
  		new_mode = PORT_PWM3CAP1;
  
  	} else if (!strcmp(verb, "mode_pwm2cap2")) {
  		new_mode = PORT_PWM2CAP2;
  #endif
  #if defined(BOARD_HAS_MULTI_PURPOSE_GPIO)
  
  	} else if (!strcmp(verb, "mode_serial")) {
  		new_mode = PORT_FULL_SERIAL;
  
  	} else if (!strcmp(verb, "mode_gpio_serial")) {
  		new_mode = PORT_GPIO_AND_SERIAL;
  
  	} else if (!strcmp(verb, "mode_pwm_serial")) {
  		new_mode = PORT_PWM_AND_SERIAL;
  
  	} else if (!strcmp(verb, "mode_pwm_gpio")) {
  		new_mode = PORT_PWM_AND_GPIO;
  #endif
  	}
  
  	/* was a new mode set? */
  	if (new_mode != PORT_MODE_UNSET) {
  
  		/* switch modes */
  		return PX4FMU::fmu_new_mode(new_mode);
  	}
  
  	if (!strcmp(verb, "test")) {
  		return test();
  	}
  
  	if (!strcmp(verb, "fake")) {
  		return fake(argc - 1, argv + 1);
  	}
  
  	return print_usage("unknown command");
  }
  
  int PX4FMU::print_usage(const char *reason)
  {
  	if (reason) {
  		PX4_WARN("%s\n", reason);
  	}
  
  	PRINT_MODULE_DESCRIPTION(
  		R"DESCR_STR(
  ### Description
  This module is responsible for driving the output and reading the input pins. For boards without a separate IO chip
  (eg. Pixracer), it uses the main channels. On boards with an IO chip (eg. Pixhawk), it uses the AUX channels, and the
  px4io driver is used for main ones.
  
  It listens on the actuator_controls topics, does the mixing and writes the PWM outputs.
  In addition it does the RC input parsing and auto-selecting the method. Supported methods are:
  - PPM
  - SBUS
  - DSM
  - SUMD
  - ST24
  
  The module is configured via mode_* commands. This defines which of the first N pins the driver should occupy.
  By using mode_pwm4 for example, pins 5 and 6 can be used by the camera trigger driver or by a PWM rangefinder
  driver. Alternatively, the fmu can be started in one of the capture modes, and then drivers can register a capture
  callback with ioctl calls.
  
  ### Implementation
  By default the module runs on the work queue, to reduce RAM usage. It can also be run in its own thread,
  specified via start flag -t, to reduce latency.
  When running on the work queue, it schedules at a fixed frequency, and the pwm rate limits the update rate of
  the actuator_controls topics. In case of running in its own thread, the module polls on the actuator_controls topic.
  Additionally the pwm rate defines the lower-level IO timer rates.
  
  ### Examples
  It is typically started with:
  $ fmu mode_pwm
  To drive all available pins.
  
  Capture input (rising and falling edges) and print on the console: start the fmu in one of the capture modes:
  $ fmu mode_pwm3cap1
  This will enable capturing on the 4th pin. Then do:
  $ fmu test
  
  Use the `pwm` command for further configurations (PWM rate, levels, ...), and the `mixer` command to load
  mixer files.
  )DESCR_STR");
  
  	PRINT_MODULE_USAGE_NAME("fmu", "driver");
  	PRINT_MODULE_USAGE_COMMAND_DESCR("start", "Start the task (without any mode set, use any of the mode_* cmds)");
  	PRINT_MODULE_USAGE_PARAM_FLAG('t', "Run as separate task instead of the work queue", true);
  
  	PRINT_MODULE_USAGE_PARAM_COMMENT("All of the mode_* commands will start the fmu if not running already");
  
  	PRINT_MODULE_USAGE_COMMAND("mode_gpio");
  	PRINT_MODULE_USAGE_COMMAND_DESCR("mode_rcin", "Only do RC input, no PWM outputs");
  	PRINT_MODULE_USAGE_COMMAND_DESCR("mode_pwm", "Select all available pins as PWM");
  #if defined(BOARD_HAS_PWM)
  	PRINT_MODULE_USAGE_COMMAND("mode_pwm1");
  #endif
  #if defined(BOARD_HAS_PWM) && BOARD_HAS_PWM >= 6
  	PRINT_MODULE_USAGE_COMMAND("mode_pwm4");
  	PRINT_MODULE_USAGE_COMMAND("mode_pwm2");
  	PRINT_MODULE_USAGE_COMMAND("mode_pwm3");
  	PRINT_MODULE_USAGE_COMMAND("mode_pwm3cap1");
  	PRINT_MODULE_USAGE_COMMAND("mode_pwm2cap2");
  #endif
  #if defined(BOARD_HAS_MULTI_PURPOSE_GPIO) // only used by px4fmu-v1 HW
  	PRINT_MODULE_USAGE_COMMAND("mode_serial");
  	PRINT_MODULE_USAGE_COMMAND("mode_gpio_serial");
  	PRINT_MODULE_USAGE_COMMAND("mode_pwm_serial");
  	PRINT_MODULE_USAGE_COMMAND("mode_pwm_gpio");
  #endif
  
  	PRINT_MODULE_USAGE_COMMAND_DESCR("bind", "Send a DSM bind command (module must be running)");
  
  	PRINT_MODULE_USAGE_COMMAND_DESCR("sensor_reset", "Do a sensor reset (SPI bus)");
  	PRINT_MODULE_USAGE_ARG("<ms>", "Delay time in ms between reset and re-enabling", true);
  	PRINT_MODULE_USAGE_COMMAND_DESCR("peripheral_reset", "Reset board peripherals");
  	PRINT_MODULE_USAGE_ARG("<ms>", "Delay time in ms between reset and re-enabling", true);
  
  	PRINT_MODULE_USAGE_COMMAND_DESCR("i2c", "Configure I2C clock rate");
  	PRINT_MODULE_USAGE_ARG("<bus_id> <rate>", "Specify the bus id (>=0) and rate in Hz", false);
  
  	PRINT_MODULE_USAGE_COMMAND_DESCR("test", "Test inputs and outputs");
  	PRINT_MODULE_USAGE_COMMAND_DESCR("fake", "Arm and send an actuator controls command");
  	PRINT_MODULE_USAGE_ARG("<roll> <pitch> <yaw> <thrust>", "Control values in range [-100, 100]", false);
  	PRINT_MODULE_USAGE_DEFAULT_COMMANDS();
  
  	return 0;
  }
  
  int PX4FMU::print_status()
  {
  	PX4_INFO("Running %s", (_run_as_task ? "as task" : "on work queue"));
  
  	if (!_run_as_task) {
  		PX4_INFO("Max update rate: %i Hz", _current_update_rate);
  	}
  
  	PX4_INFO("RC scan state: %s", RC_SCAN_STRING[_rc_scan_state]);
  #ifdef RC_SERIAL_PORT
  	PX4_INFO("SBUS frame drops: %u", sbus_dropped_frames());
  #endif
  	const char *mode_str = nullptr;
  
  	switch (_mode) {
  	case MODE_1PWM: mode_str = "pwm1"; break;
  
  	case MODE_2PWM: mode_str = "pwm2"; break;
  
  	case MODE_3PWM: mode_str = "pwm3"; break;
  
  	case MODE_4PWM: mode_str = "pwm4"; break;
  
  	case MODE_2PWM2CAP: mode_str = "pwm2cap2"; break;
  
  	case MODE_3PWM1CAP: mode_str = "pwm3cap1"; break;
  
  	case MODE_6PWM: mode_str = "pwm6"; break;
  
  	case MODE_8PWM: mode_str = "pwm8"; break;
  
  	case MODE_4CAP: mode_str = "cap4"; break;
  
  	case MODE_5CAP: mode_str = "cap5"; break;
  
  	case MODE_6CAP: mode_str = "cap6"; break;
  
  	case MODE_NONE: mode_str = "no pwm"; break;
  
  	default:
  		break;
  	}
  
  	if (mode_str) {
  		PX4_INFO("PWM Mode: %s", mode_str);
  	}
  
  	return 0;
  }
  
  extern "C" __EXPORT int fmu_main(int argc, char *argv[]);
  
  int
  fmu_main(int argc, char *argv[])
  {
  	return PX4FMU::main(argc, argv);
  }
  