text: /****************************************************************************
   *
   *   Copyright (c) 2012-2014 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 px4io.cpp
   * Driver for the PX4IO board.
   *
   * PX4IO is connected via I2C or DMA enabled high-speed UART.
   */
  
  #include <nuttx/config.h>
  
  #include <sys/types.h>
  #include <stdint.h>
  #include <stdbool.h>
  #include <assert.h>
  #include <debug.h>
  #include <time.h>
  #include <queue.h>
  #include <errno.h>
  #include <string.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <math.h>
  #include <crc32.h>
  
  #include <arch/board/board.h>
  
  #include <drivers/device/device.h>
  #include <drivers/drv_rc_input.h>
  #include <drivers/drv_pwm_output.h>
  #include <drivers/drv_sbus.h>
  #include <drivers/drv_gpio.h>
  #include <drivers/drv_hrt.h>
  #include <drivers/drv_mixer.h>
  
  #include <systemlib/mixer/mixer.h>
  #include <systemlib/perf_counter.h>
  #include <systemlib/err.h>
  #include <systemlib/systemlib.h>
  #include <systemlib/scheduling_priorities.h>
  #include <systemlib/param/param.h>
  #include <systemlib/circuit_breaker.h>
  
  #include <uORB/topics/actuator_controls.h>
  #include <uORB/topics/actuator_outputs.h>
  #include <uORB/topics/actuator_armed.h>
  #include <uORB/topics/safety.h>
  #include <uORB/topics/vehicle_control_mode.h>
  #include <uORB/topics/vehicle_command.h>
  #include <uORB/topics/rc_channels.h>
  #include <uORB/topics/battery_status.h>
  #include <uORB/topics/servorail_status.h>
  #include <uORB/topics/parameter_update.h>
  
  #include <debug.h>
  
  #include <mavlink/mavlink_log.h>
  #include <modules/px4iofirmware/protocol.h>
  
  #include "uploader.h"
  
  #include "modules/dataman/dataman.h"
  
  extern device::Device *PX4IO_i2c_interface() weak_function;
  extern device::Device *PX4IO_serial_interface() weak_function;
  
  #define PX4IO_SET_DEBUG			_IOC(0xff00, 0)
  #define PX4IO_INAIR_RESTART_ENABLE	_IOC(0xff00, 1)
  #define PX4IO_REBOOT_BOOTLOADER		_IOC(0xff00, 2)
  #define PX4IO_CHECK_CRC			_IOC(0xff00, 3)
  
  #define UPDATE_INTERVAL_MIN		2			// 2 ms	-> 500 Hz
  #define ORB_CHECK_INTERVAL		200000		// 200 ms -> 5 Hz
  #define IO_POLL_INTERVAL		20000		// 20 ms -> 50 Hz
  
  /**
   * The PX4IO class.
   *
   * Encapsulates PX4FMU to PX4IO communications modeled as file operations.
   */
  class PX4IO : public device::CDev
  {
  public:
  	/**
  	 * Constructor.
  	 *
  	 * Initialize all class variables.
  	 */
  	PX4IO(device::Device *interface);
  
  	/**
  	 * Destructor.
  	 *
  	 * Wait for worker thread to terminate.
  	 */
  	virtual ~PX4IO();
  
  	/**
  	 * Initialize the PX4IO class.
  	 *
  	 * Retrieve relevant initial system parameters. Initialize PX4IO registers.
  	 */
  	virtual int		init();
  
  	/**
  	 * Initialize the PX4IO class.
  	 *
  	 * Retrieve relevant initial system parameters. Initialize PX4IO registers.
  	 *
  	 * @param disable_rc_handling set to true to forbid override / RC handling on IO
  	 */
  	int			init(bool disable_rc_handling);
  
  	/**
  	 * Detect if a PX4IO is connected.
  	 *
  	 * Only validate if there is a PX4IO to talk to.
  	 */
  	virtual int		detect();
  
  	/**
  	 * IO Control handler.
  	 *
  	 * Handle all IOCTL calls to the PX4IO file descriptor.
  	 *
  	 * @param[in] filp file handle (not used). This function is always called directly through object reference
  	 * @param[in] cmd the IOCTL command
  	 * @param[in] the IOCTL command parameter (optional)
  	 */
  	virtual int		ioctl(file *filp, int cmd, unsigned long arg);
  
  	/**
  	 * write handler.
  	 *
  	 * Handle writes to the PX4IO file descriptor.
  	 *
  	 * @param[in] filp file handle (not used). This function is always called directly through object reference
  	 * @param[in] buffer pointer to the data buffer to be written
  	 * @param[in] len size in bytes to be written
  	 * @return number of bytes written
  	 */
  	virtual ssize_t		write(file *filp, const char *buffer, size_t len);
  
  	/**
  	* Set the update rate for actuator outputs from FMU to IO.
  	*
  	* @param[in] rate		The rate in Hz actuator outpus are sent to IO.
  	* 			Min 10 Hz, max 400 Hz
  	*/
  	int      		set_update_rate(int rate);
  
  	/**
  	* Set the battery current scaling and bias
  	*
  	* @param[in] amp_per_volt
  	* @param[in] amp_bias
  	*/
  	void      		set_battery_current_scaling(float amp_per_volt, float amp_bias);
  
  	/**
  	 * Push failsafe values to IO.
  	 *
  	 * @param[in] vals	Failsafe control inputs: in us PPM (900 for zero, 1500 for centered, 2100 for full)
  	 * @param[in] len	Number of channels, could up to 8
  	 */
  	int			set_failsafe_values(const uint16_t *vals, unsigned len);
  
  	/**
  	 * Disable RC input handling
  	 */
  	int			disable_rc_handling();
  
  	/**
  	 * Print IO status.
  	 *
  	 * Print all relevant IO status information
  	 *
  	 * @param extended_status Shows more verbose information (in particular RC config)
  	 */
  	void			print_status(bool extended_status);
  
  	/**
  	 * Fetch and print debug console output.
  	 */
  	int			print_debug();
  
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V1
  	/**
  	 * Set the DSM VCC is controlled by relay one flag
  	 *
  	 * @param[in] enable true=DSM satellite VCC is controlled by relay1, false=DSM satellite VCC not controlled
  	 */
  	inline void		set_dsm_vcc_ctl(bool enable) {
  		_dsm_vcc_ctl = enable;
  	};
  
  	/**
  	 * Get the DSM VCC is controlled by relay one flag
  	 *
  	 * @return true=DSM satellite VCC is controlled by relay1, false=DSM satellite VCC not controlled
  	 */
  	inline bool		get_dsm_vcc_ctl() {
  		return _dsm_vcc_ctl;
  	};
  #endif
  
  	inline uint16_t		system_status() const {return _status;}
  
  private:
  	device::Device		*_interface;
  
  	// XXX
  	unsigned		_hardware;		///< Hardware revision
  	unsigned		_max_actuators;		///< Maximum # of actuators supported by PX4IO
  	unsigned		_max_controls;		///< Maximum # of controls supported by PX4IO
  	unsigned		_max_rc_input;		///< Maximum receiver channels supported by PX4IO
  	unsigned		_max_relays;		///< Maximum relays supported by PX4IO
  	unsigned		_max_transfer;		///< Maximum number of I2C transfers supported by PX4IO
  
  	unsigned 		_update_interval;	///< Subscription interval limiting send rate
  	bool			_rc_handling_disabled;	///< If set, IO does not evaluate, but only forward the RC values
  	unsigned		_rc_chan_count;		///< Internal copy of the last seen number of RC channels
  	uint64_t		_rc_last_valid;		///< last valid timestamp
  
  	volatile int		_task;			///< worker task id
  	volatile bool		_task_should_exit;	///< worker terminate flag
  
  	int			_mavlink_fd;		///< mavlink file descriptor.
  
  	perf_counter_t		_perf_update;		///<local performance counter for status updates
  	perf_counter_t		_perf_write;		///<local performance counter for PWM control writes
  	perf_counter_t		_perf_chan_count;	///<local performance counter for channel number changes
  
  	/* cached IO state */
  	uint16_t		_status;		///< Various IO status flags
  	uint16_t		_alarms;		///< Various IO alarms
  
  	/* subscribed topics */
  	int			_t_actuator_controls_0;	///< actuator controls group 0 topic
  	int			_t_actuator_controls_1;	///< actuator controls group 1 topic
  	int			_t_actuator_controls_2;	///< actuator controls group 2 topic
  	int			_t_actuator_controls_3;	///< actuator controls group 3 topic
  	int			_t_actuator_armed;	///< system armed control topic
  	int 			_t_vehicle_control_mode;///< vehicle control mode topic
  	int			_t_param;		///< parameter update topic
  	int			_t_vehicle_command;	///< vehicle command topic
  
  	/* advertised topics */
  	orb_advert_t 		_to_input_rc;		///< rc inputs from io
  	orb_advert_t		_to_outputs;		///< mixed servo outputs topic
  	orb_advert_t		_to_battery;		///< battery status / voltage
  	orb_advert_t		_to_servorail;		///< servorail status
  	orb_advert_t		_to_safety;		///< status of safety
  
  	actuator_outputs_s	_outputs;		///< mixed outputs
  	servorail_status_s	_servorail_status;	///< servorail status
  
  	bool			_primary_pwm_device;	///< true if we are the default PWM output
  	bool			_lockdown_override;	///< allow to override the safety lockdown
  
  	float			_battery_amp_per_volt;	///< current sensor amps/volt
  	float			_battery_amp_bias;	///< current sensor bias
  	float			_battery_mamphour_total;///< amp hours consumed so far
  	uint64_t		_battery_last_timestamp;///< last amp hour calculation timestamp
  	bool			_cb_flighttermination;	///< true if the flight termination circuit breaker is enabled
  
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V1
  	bool			_dsm_vcc_ctl;		///< true if relay 1 controls DSM satellite RX power
  #endif
  
  	/**
  	 * Trampoline to the worker task
  	 */
  	static void		task_main_trampoline(int argc, char *argv[]);
  
  	/**
  	 * worker task
  	 */
  	void			task_main();
  
  	/**
  	 * Send controls for one group to IO
  	 */
  	int			io_set_control_state(unsigned group);
  
  	/**
  	 * Send all controls to IO
  	 */
  	int			io_set_control_groups();
  
  	/**
  	 * Update IO's arming-related state
  	 */
  	int			io_set_arming_state();
  
  	/**
  	 * Push RC channel configuration to IO.
  	 */
  	int			io_set_rc_config();
  
  	/**
  	 * Fetch status and alarms from IO
  	 *
  	 * Also publishes battery voltage/current.
  	 */
  	int			io_get_status();
  
  	/**
  	 * Disable RC input handling
  	 */
  	int			io_disable_rc_handling();
  
  	/**
  	 * Fetch RC inputs from IO.
  	 *
  	 * @param input_rc	Input structure to populate.
  	 * @return		OK if data was returned.
  	 */
  	int			io_get_raw_rc_input(rc_input_values &input_rc);
  
  	/**
  	 * Fetch and publish raw RC input data.
  	 */
  	int			io_publish_raw_rc();
  
  	/**
  	 * Fetch and publish the PWM servo outputs.
  	 */
  	int			io_publish_pwm_outputs();
  
  	/**
  	 * write register(s)
  	 *
  	 * @param page		Register page to write to.
  	 * @param offset	Register offset to start writing at.
  	 * @param values	Pointer to array of values to write.
  	 * @param num_values	The number of values to write.
  	 * @return		OK if all values were successfully written.
  	 */
  	int			io_reg_set(uint8_t page, uint8_t offset, const uint16_t *values, unsigned num_values);
  
  	/**
  	 * write a register
  	 *
  	 * @param page		Register page to write to.
  	 * @param offset	Register offset to write to.
  	 * @param value		Value to write.
  	 * @return		OK if the value was written successfully.
  	 */
  	int			io_reg_set(uint8_t page, uint8_t offset, const uint16_t value);
  
  	/**
  	 * read register(s)
  	 *
  	 * @param page		Register page to read from.
  	 * @param offset	Register offset to start reading from.
  	 * @param values	Pointer to array where values should be stored.
  	 * @param num_values	The number of values to read.
  	 * @return		OK if all values were successfully read.
  	 */
  	int			io_reg_get(uint8_t page, uint8_t offset, uint16_t *values, unsigned num_values);
  
  	/**
  	 * read a register
  	 *
  	 * @param page		Register page to read from.
  	 * @param offset	Register offset to start reading from.
  	 * @return		Register value that was read, or _io_reg_get_error on error.
  	 */
  	uint32_t		io_reg_get(uint8_t page, uint8_t offset);
  	static const uint32_t	_io_reg_get_error = 0x80000000;
  
  	/**
  	 * modify a register
  	 *
  	 * @param page		Register page to modify.
  	 * @param offset	Register offset to modify.
  	 * @param clearbits	Bits to clear in the register.
  	 * @param setbits	Bits to set in the register.
  	 */
  	int			io_reg_modify(uint8_t page, uint8_t offset, uint16_t clearbits, uint16_t setbits);
  
  	/**
  	 * Send mixer definition text to IO
  	 */
  	int			mixer_send(const char *buf, unsigned buflen, unsigned retries = 3);
  
  	/**
  	 * Handle a status update from IO.
  	 *
  	 * Publish IO status information if necessary.
  	 *
  	 * @param status	The status register
  	 */
  	int			io_handle_status(uint16_t status);
  
  	/**
  	 * Handle an alarm update from IO.
  	 *
  	 * Publish IO alarm information if necessary.
  	 *
  	 * @param alarm		The status register
  	 */
  	int			io_handle_alarms(uint16_t alarms);
  
  	/**
  	 * Handle issuing dsm bind ioctl to px4io.
  	 *
  	 * @param dsmMode	0:dsm2, 1:dsmx
  	 */
  	void			dsm_bind_ioctl(int dsmMode);
  
  	/**
  	 * Handle a battery update from IO.
  	 *
  	 * Publish IO battery information if necessary.
  	 *
  	 * @param vbatt		vbatt register
  	 * @param ibatt		ibatt register
  	 */
  	void			io_handle_battery(uint16_t vbatt, uint16_t ibatt);
  
  	/**
  	 * Handle a servorail update from IO.
  	 *
  	 * Publish servo rail information if necessary.
  	 *
  	 * @param vservo	vservo register
  	 * @param vrssi 	vrssi register
  	 */
  	void			io_handle_vservo(uint16_t vservo, uint16_t vrssi);
  
  	/* do not allow to copy this class due to ptr data members */
  	PX4IO(const PX4IO&);
  	PX4IO operator=(const PX4IO&);
  };
  
  namespace
  {
  
  PX4IO	*g_dev = nullptr;
  
  }
  
  PX4IO::PX4IO(device::Device *interface) :
  	CDev("px4io", PX4IO_DEVICE_PATH),
  	_interface(interface),
  	_hardware(0),
  	_max_actuators(0),
  	_max_controls(0),
  	_max_rc_input(0),
  	_max_relays(0),
  	_max_transfer(16),	/* sensible default */
  	_update_interval(0),
  	_rc_handling_disabled(false),
  	_rc_chan_count(0),
  	_rc_last_valid(0),
  	_task(-1),
  	_task_should_exit(false),
  	_mavlink_fd(-1),
  	_perf_update(perf_alloc(PC_ELAPSED, "io update")),
  	_perf_write(perf_alloc(PC_ELAPSED, "io write")),
  	_perf_chan_count(perf_alloc(PC_COUNT, "io rc #")),
  	_status(0),
  	_alarms(0),
  	_t_actuator_controls_0(-1),
  	_t_actuator_controls_1(-1),
  	_t_actuator_controls_2(-1),
  	_t_actuator_controls_3(-1),
  	_t_actuator_armed(-1),
  	_t_vehicle_control_mode(-1),
  	_t_param(-1),
  	_t_vehicle_command(-1),
  	_to_input_rc(0),
  	_to_outputs(0),
  	_to_battery(0),
  	_to_servorail(0),
  	_to_safety(0),
  	_outputs{},
  	_servorail_status{},
  	_primary_pwm_device(false),
  	_lockdown_override(false),
  	_battery_amp_per_volt(90.0f / 5.0f), // this matches the 3DR current sensor
  	_battery_amp_bias(0),
  	_battery_mamphour_total(0),
  	_battery_last_timestamp(0),
  	_cb_flighttermination(true)
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V1
  	, _dsm_vcc_ctl(false)
  #endif
  
  {
  	/* we need this potentially before it could be set in task_main */
  	g_dev = this;
  
  	_debug_enabled = false;
  	_servorail_status.rssi_v = 0;
  }
  
  PX4IO::~PX4IO()
  {
  	/* tell the task we want it to go away */
  	_task_should_exit = true;
  
  	/* spin waiting for the task to stop */
  	for (unsigned i = 0; (i < 10) && (_task != -1); i++) {
  		/* give it another 100ms */
  		usleep(100000);
  	}
  
  	/* well, kill it anyway, though this will probably crash */
  	if (_task != -1)
  		task_delete(_task);
  
  	if (_interface != nullptr)
  		delete _interface;
  
  	/* deallocate perfs */
  	perf_free(_perf_update);
  	perf_free(_perf_write);
  	perf_free(_perf_chan_count);
  
  	g_dev = nullptr;
  }
  
  int
  PX4IO::detect()
  {
  	int ret;
  
  	if (_task == -1) {
  
  		/* do regular cdev init */
  		ret = CDev::init();
  
  		if (ret != OK)
  			return ret;
  
  		/* get some parameters */
  		unsigned protocol = io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_PROTOCOL_VERSION);
  
  		if (protocol != PX4IO_PROTOCOL_VERSION) {
  			if (protocol == _io_reg_get_error) {
  				log("IO not installed");
  
  			} else {
  				log("IO version error");
  				mavlink_log_emergency(_mavlink_fd, "IO VERSION MISMATCH, PLEASE UPGRADE SOFTWARE!");
  			}
  
  			return -1;
  		}
  	}
  
  	log("IO found");
  
  	return 0;
  }
  
  int
  PX4IO::init(bool rc_handling_disabled) {
  	_rc_handling_disabled = rc_handling_disabled;
  	return init();
  }
  
  int
  PX4IO::init()
  {
  	int ret;
  	param_t sys_restart_param;
  	int sys_restart_val = DM_INIT_REASON_VOLATILE;
  
  	ASSERT(_task == -1);
  
  	sys_restart_param = param_find("SYS_RESTART_TYPE");
  	if (sys_restart_param != PARAM_INVALID) {
  		/* Indicate restart type is unknown */
  		param_set(sys_restart_param, &sys_restart_val);
  	}
  
  	/* do regular cdev init */
  	ret = CDev::init();
  
  	if (ret != OK)
  		return ret;
  
  	/* get some parameters */
  	unsigned protocol = io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_PROTOCOL_VERSION);
  
  	if (protocol == _io_reg_get_error) {
  		log("failed to communicate with IO");
  		mavlink_log_emergency(_mavlink_fd, "[IO] failed to communicate with IO, abort.");
  		return -1;
  	}
  
  	if (protocol != PX4IO_PROTOCOL_VERSION) {
  		log("protocol/firmware mismatch");
  		mavlink_log_emergency(_mavlink_fd, "[IO] protocol/firmware mismatch, abort.");
  		return -1;
  	}
  
  	_hardware      = io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_HARDWARE_VERSION);
  	_max_actuators = io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_ACTUATOR_COUNT);
  	_max_controls  = io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_CONTROL_COUNT);
  	_max_relays    = io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_RELAY_COUNT);
  	_max_transfer  = io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_MAX_TRANSFER) - 2;
  	_max_rc_input  = io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_RC_INPUT_COUNT);
  
  	if ((_max_actuators < 1) || (_max_actuators > 255) ||
  	    (_max_relays > 32)   ||
  	    (_max_transfer < 16) || (_max_transfer > 255)  ||
  	    (_max_rc_input < 1)  || (_max_rc_input > 255)) {
  
  		log("config read error");
  		mavlink_log_emergency(_mavlink_fd, "[IO] config read fail, abort.");
  		return -1;
  	}
  
  	if (_max_rc_input > RC_INPUT_MAX_CHANNELS)
  		_max_rc_input = RC_INPUT_MAX_CHANNELS;
  
  	/*
  	 * Check for IO flight state - if FMU was flagged to be in
  	 * armed state, FMU is recovering from an in-air reset.
  	 * Read back status and request the commander to arm
  	 * in this case.
  	 */
  
  	uint16_t reg;
  
  	/* get IO's last seen FMU state */
  	ret = io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, &reg, sizeof(reg));
  
  	if (ret != OK)
  		return ret;
  
  	/*
  	 * in-air restart is only tried if the IO board reports it is
  	 * already armed, and has been configured for in-air restart
  	 */
  	if ((reg & PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK) &&
  	    (reg & PX4IO_P_SETUP_ARMING_FMU_ARMED)) {
  
  		/* get a status update from IO */
  		io_get_status();
  
  		mavlink_log_emergency(_mavlink_fd, "[IO] RECOVERING FROM FMU IN-AIR RESTART");
  		log("INAIR RESTART RECOVERY (needs commander app running)");
  
  		/* WARNING: COMMANDER app/vehicle status must be initialized.
  		 * If this fails (or the app is not started), worst-case IO
  		 * remains untouched (so manual override is still available).
  		 */
  
  		int safety_sub = orb_subscribe(ORB_ID(actuator_armed));
  		/* fill with initial values, clear updated flag */
  		struct actuator_armed_s safety;
  		uint64_t try_start_time = hrt_absolute_time();
  		bool updated = false;
  
  		/* keep checking for an update, ensure we got a arming information,
  		   not something that was published a long time ago. */
  		do {
  			orb_check(safety_sub, &updated);
  
  			if (updated) {
  				/* got data, copy and exit loop */
  				orb_copy(ORB_ID(actuator_armed), safety_sub, &safety);
  				break;
  			}
  
  			/* wait 10 ms */
  			usleep(10000);
  
  			/* abort after 5s */
  			if ((hrt_absolute_time() - try_start_time) / 1000 > 3000) {
  				log("failed to recover from in-air restart (1), aborting IO driver init.");
  				return 1;
  			}
  
  		} while (true);
  
  		/* send command to arm system via command API */
  		vehicle_command_s cmd;
  		/* send this to itself */
  		param_t sys_id_param = param_find("MAV_SYS_ID");
  		param_t comp_id_param = param_find("MAV_COMP_ID");
  
  		int32_t sys_id;
  		int32_t comp_id;
  
  		if (param_get(sys_id_param, &sys_id)) {
  			errx(1, "PRM SYSID");
  		}
  
  		if (param_get(comp_id_param, &comp_id)) {
  			errx(1, "PRM CMPID");
  		}
  
  		cmd.target_system = sys_id;
  		cmd.target_component = comp_id;
  		cmd.source_system = sys_id;
  		cmd.source_component = comp_id;
  		/* request arming */
  		cmd.param1 = 1.0f;
  		cmd.param2 = 0;
  		cmd.param3 = 0;
  		cmd.param4 = 0;
  		cmd.param5 = 0;
  		cmd.param6 = 0;
  		cmd.param7 = 0;
  		cmd.command = VEHICLE_CMD_COMPONENT_ARM_DISARM;
  
  		/* ask to confirm command */
  		cmd.confirmation =  1;
  
  		/* send command once */
  		orb_advert_t pub = orb_advertise(ORB_ID(vehicle_command), &cmd);
  
  		/* spin here until IO's state has propagated into the system */
  		do {
  			orb_check(safety_sub, &updated);
  
  			if (updated) {
  				orb_copy(ORB_ID(actuator_armed), safety_sub, &safety);
  			}
  
  			/* wait 50 ms */
  			usleep(50000);
  
  			/* abort after 5s */
  			if ((hrt_absolute_time() - try_start_time) / 1000 > 2000) {
  				log("failed to recover from in-air restart (2), aborting IO driver init.");
  				return 1;
  			}
  
  			/* re-send if necessary */
  			if (!safety.armed) {
  				orb_publish(ORB_ID(vehicle_command), pub, &cmd);
  				log("re-sending arm cmd");
  			}
  
  			/* keep waiting for state change for 2 s */
  		} while (!safety.armed);
  
  		/* Indicate restart type is in-flight */
  		sys_restart_val = DM_INIT_REASON_IN_FLIGHT;
  		param_set(sys_restart_param, &sys_restart_val);
  
  
  		/* regular boot, no in-air restart, init IO */
  
  	} else {
  
  		/* dis-arm IO before touching anything */
  		io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING,
  			      PX4IO_P_SETUP_ARMING_FMU_ARMED |
  			      PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK |
  			      PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK |
  			      PX4IO_P_SETUP_ARMING_ALWAYS_PWM_ENABLE, 0);
  
  		if (_rc_handling_disabled) {
  			ret = io_disable_rc_handling();
  
  			if (ret != OK) {
  				log("failed disabling RC handling");
  				return ret;
  			}
  
  		} else {
  			/* publish RC config to IO */
  			ret = io_set_rc_config();
  
  			if (ret != OK) {
  				log("failed to update RC input config");
  				mavlink_log_info(_mavlink_fd, "[IO] RC config upload fail");
  				return ret;
  			}
  		}
  
  		/* Indicate restart type is power on */
  		sys_restart_val = DM_INIT_REASON_POWER_ON;
  		param_set(sys_restart_param, &sys_restart_val);
  
  	}
  
  	/* try to claim the generic PWM output device node as well - it's OK if we fail at this */
  	ret = register_driver(PWM_OUTPUT_DEVICE_PATH, &fops, 0666, (void *)this);
  
  	if (ret == OK) {
  		log("default PWM output device");
  		_primary_pwm_device = true;
  	}
  
  	/* start the IO interface task */
  	_task = task_spawn_cmd("px4io",
  					SCHED_DEFAULT,
  					SCHED_PRIORITY_ACTUATOR_OUTPUTS,
  					2000,
  					(main_t)&PX4IO::task_main_trampoline,
  					nullptr);
  
  	if (_task < 0) {
  		debug("task start failed: %d", errno);
  		return -errno;
  	}
  
  	mavlink_log_info(_mavlink_fd, "[IO] init ok");
  
  	return OK;
  }
  
  void
  PX4IO::task_main_trampoline(int argc, char *argv[])
  {
  	g_dev->task_main();
  }
  
  void
  PX4IO::task_main()
  {
  	hrt_abstime poll_last = 0;
  	hrt_abstime orb_check_last = 0;
  
  	_mavlink_fd = ::open(MAVLINK_LOG_DEVICE, 0);
  
  	/*
  	 * Subscribe to the appropriate PWM output topic based on whether we are the
  	 * primary PWM output or not.
  	 */
  	_t_actuator_controls_0 = orb_subscribe(ORB_ID(actuator_controls_0));
  	orb_set_interval(_t_actuator_controls_0, 20);		/* default to 50Hz */
  	_t_actuator_controls_1 = orb_subscribe(ORB_ID(actuator_controls_1));
  	orb_set_interval(_t_actuator_controls_1, 33);		/* default to 30Hz */
  	_t_actuator_controls_2 = orb_subscribe(ORB_ID(actuator_controls_2));
  	orb_set_interval(_t_actuator_controls_2, 33);		/* default to 30Hz */
  	_t_actuator_controls_3 = orb_subscribe(ORB_ID(actuator_controls_3));
  	orb_set_interval(_t_actuator_controls_3, 33);		/* default to 30Hz */
  	_t_actuator_armed = orb_subscribe(ORB_ID(actuator_armed));
  	_t_vehicle_control_mode = orb_subscribe(ORB_ID(vehicle_control_mode));
  	_t_param = orb_subscribe(ORB_ID(parameter_update));
  	_t_vehicle_command = orb_subscribe(ORB_ID(vehicle_command));
  
  	if ((_t_actuator_controls_0 < 0) ||
  	    (_t_actuator_armed < 0) ||
  	    (_t_vehicle_control_mode < 0) ||
  	    (_t_param < 0) ||
  	    (_t_vehicle_command < 0)) {
  		log("subscription(s) failed");
  		goto out;
  	}
  
  	/* poll descriptor */
  	pollfd fds[1];
  	fds[0].fd = _t_actuator_controls_0;
  	fds[0].events = POLLIN;
  
  	/* lock against the ioctl handler */
  	lock();
  
  	/* loop talking to IO */
  	while (!_task_should_exit) {
  
  		/* adjust update interval */
  		if (_update_interval != 0) {
  			if (_update_interval < UPDATE_INTERVAL_MIN)
  				_update_interval = UPDATE_INTERVAL_MIN;
  
  			if (_update_interval > 100)
  				_update_interval = 100;
  
  			orb_set_interval(_t_actuator_controls_0, _update_interval);
  			/*
  			 * NOT changing the rate of groups 1-3 here, because only attitude
  			 * really needs to run fast.
  			 */
  			_update_interval = 0;
  		}
  
  		/* sleep waiting for topic updates, but no more than 20ms */
  		unlock();
  		int ret = ::poll(fds, 1, 20);
  		lock();
  
  		/* this would be bad... */
  		if (ret < 0) {
  			log("poll error %d", errno);
  			continue;
  		}
  
  		perf_begin(_perf_update);
  		hrt_abstime now = hrt_absolute_time();
  
  		/* if we have new control data from the ORB, handle it */
  		if (fds[0].revents & POLLIN) {
  
  			/* we're not nice to the lower-priority control groups and only check them
  			   when the primary group updated (which is now). */
  			(void)io_set_control_groups();
  		}
  
  		if (now >= poll_last + IO_POLL_INTERVAL) {
  			/* run at 50Hz */
  			poll_last = now;
  
  			/* pull status and alarms from IO */
  			io_get_status();
  
  			/* get raw R/C input from IO */
  			io_publish_raw_rc();
  
  			/* fetch PWM outputs from IO */
  			io_publish_pwm_outputs();
  		}
  
  		if (now >= orb_check_last + ORB_CHECK_INTERVAL) {
  			/* run at 5Hz */
  			orb_check_last = now;
  
  			/* try to claim the MAVLink log FD */
  			if (_mavlink_fd < 0)
  				_mavlink_fd = ::open(MAVLINK_LOG_DEVICE, 0);
  
  			/* check updates on uORB topics and handle it */
  			bool updated = false;
  
  			/* arming state */
  			orb_check(_t_actuator_armed, &updated);
  
  			if (!updated) {
  				orb_check(_t_vehicle_control_mode, &updated);
  			}
  
  			if (updated) {
  				io_set_arming_state();
  			}
  
  			/* vehicle command */
  			orb_check(_t_vehicle_command, &updated);
  
  			if (updated) {
  				struct vehicle_command_s cmd;
  				orb_copy(ORB_ID(vehicle_command), _t_vehicle_command, &cmd);
  
  				// Check for a DSM pairing command
  				if (((int)cmd.command == VEHICLE_CMD_START_RX_PAIR) && ((int)cmd.param1 == 0)) {
  					dsm_bind_ioctl((int)cmd.param2);
  				}
  			}
  
  			/*
  			 * If parameters have changed, re-send RC mappings to IO
  			 *
  			 * XXX this may be a bit spammy
  			 */
  			orb_check(_t_param, &updated);
  
  			if (updated) {
  				parameter_update_s pupdate;
  				orb_copy(ORB_ID(parameter_update), _t_param, &pupdate);
  
  				int32_t dsm_bind_val;
  				param_t dsm_bind_param;
  
  				/* see if bind parameter has been set, and reset it to -1 */
  				param_get(dsm_bind_param = 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(dsm_bind_param, &dsm_bind_val);
  				}
  
  				/* re-upload RC input config as it may have changed */
  				io_set_rc_config();
  
  				/* re-set the battery scaling */
  				int32_t voltage_scaling_val;
  				param_t voltage_scaling_param;
  
  				/* set battery voltage scaling */
  				param_get(voltage_scaling_param = param_find("BAT_V_SCALE_IO"), &voltage_scaling_val);
  
  				/* send scaling voltage to IO */
  				uint16_t scaling = voltage_scaling_val;
  				int pret = io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_VBATT_SCALE, &scaling, 1);
  
  				if (pret != OK) {
  					log("vscale upload failed");
  				}
  
  				/* send RC throttle failsafe value to IO */
  				int32_t failsafe_param_val;
  				param_t failsafe_param = param_find("RC_FAILS_THR");
  
  				if (failsafe_param != PARAM_INVALID) {
  
  					param_get(failsafe_param, &failsafe_param_val);
  
  					if (failsafe_param_val > 0) {
  
  						uint16_t failsafe_thr = failsafe_param_val;
  						pret = io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_RC_THR_FAILSAFE_US, &failsafe_thr, 1);
  						if (pret != OK) {
  							log("failsafe upload failed, FS: %d us", (int)failsafe_thr);
  						}
  					}
  				}
  
  				int32_t safety_param_val;
  				param_t safety_param = param_find("RC_FAILS_THR");
  
  				if (safety_param != PARAM_INVALID) {
  
  					param_get(safety_param, &safety_param_val);
  
  					if (safety_param_val == PX4IO_FORCE_SAFETY_MAGIC) {
  						/* disable IO safety if circuit breaker asked for it */
  						(void)io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FORCE_SAFETY_OFF, safety_param_val);
  					}
  				}
  
  				/* Update Circuit breakers */
  				_cb_flighttermination = circuit_breaker_enabled("CBRK_FLIGHTTERM", CBRK_FLIGHTTERM_KEY);
  
  			}
  
  		}
  
  		perf_end(_perf_update);
  	}
  
  	unlock();
  
  out:
  	debug("exiting");
  
  	/* clean up the alternate device node */
  	if (_primary_pwm_device)
  		unregister_driver(PWM_OUTPUT_DEVICE_PATH);
  
  	/* tell the dtor that we are exiting */
  	_task = -1;
  	_exit(0);
  }
  
  int
  PX4IO::io_set_control_groups()
  {
  	int ret = io_set_control_state(0);
  
  	/* send auxiliary control groups */
  	(void)io_set_control_state(1);
  	(void)io_set_control_state(2);
  	(void)io_set_control_state(3);
  
  	return ret;
  }
  
  int
  PX4IO::io_set_control_state(unsigned group)
  {
  	actuator_controls_s	controls;	///< actuator outputs
  	uint16_t 		regs[_max_actuators];
  
  	/* get controls */
  	bool changed;
  
  	switch (group) {
  		case 0:
  		{
  			orb_check(_t_actuator_controls_0, &changed);
  
  			if (changed) {
  				orb_copy(ORB_ID(actuator_controls_0), _t_actuator_controls_0, &controls);
  			}
  		}
  		break;
  		case 1:
  		{
  			orb_check(_t_actuator_controls_1, &changed);
  
  			if (changed) {
  				orb_copy(ORB_ID(actuator_controls_1), _t_actuator_controls_1, &controls);
  			}
  		}
  		break;
  		case 2:
  		{
  			orb_check(_t_actuator_controls_2, &changed);
  
  			if (changed) {
  				orb_copy(ORB_ID(actuator_controls_2), _t_actuator_controls_2, &controls);
  			}
  		}
  		break;
  		case 3:
  		{
  			orb_check(_t_actuator_controls_3, &changed);
  
  			if (changed) {
  				orb_copy(ORB_ID(actuator_controls_3), _t_actuator_controls_3, &controls);
  			}
  		}
  		break;
  	}
  
  	if (!changed)
  		return -1;
  
  	for (unsigned i = 0; i < _max_controls; i++)
  		regs[i] = FLOAT_TO_REG(controls.control[i]);
  
  	/* copy values to registers in IO */
  	return io_reg_set(PX4IO_PAGE_CONTROLS, group * PX4IO_PROTOCOL_MAX_CONTROL_COUNT, regs, _max_controls);
  }
  
  
  int
  PX4IO::io_set_arming_state()
  {
  	actuator_armed_s	armed;		///< system armed state
  	vehicle_control_mode_s	control_mode;	///< vehicle_control_mode
  
  	orb_copy(ORB_ID(actuator_armed), _t_actuator_armed, &armed);
  	orb_copy(ORB_ID(vehicle_control_mode), _t_vehicle_control_mode, &control_mode);
  
  	uint16_t set = 0;
  	uint16_t clear = 0;
  
  	if (armed.armed) {
  		set |= PX4IO_P_SETUP_ARMING_FMU_ARMED;
  
  	} else {
  		clear |= PX4IO_P_SETUP_ARMING_FMU_ARMED;
  	}
  
  	if (armed.lockdown && !_lockdown_override) {
  		set |= PX4IO_P_SETUP_ARMING_LOCKDOWN;
  	} else {
  		clear |= PX4IO_P_SETUP_ARMING_LOCKDOWN;
  	}
  
  	/* Do not set failsafe if circuit breaker is enabled */
  	if (armed.force_failsafe && !_cb_flighttermination) {
  		set |= PX4IO_P_SETUP_ARMING_FORCE_FAILSAFE;
  	} else {
  		clear |= PX4IO_P_SETUP_ARMING_FORCE_FAILSAFE;
  	}
  
  	// XXX this is for future support in the commander
  	// but can be removed if unneeded
  	// if (armed.termination_failsafe) {
  	// 	set |= PX4IO_P_SETUP_ARMING_TERMINATION_FAILSAFE;
  	// } else {
  	// 	clear |= PX4IO_P_SETUP_ARMING_TERMINATION_FAILSAFE;
  	// }
  
  	if (armed.ready_to_arm) {
  		set |= PX4IO_P_SETUP_ARMING_IO_ARM_OK;
  
  	} else {
  		clear |= PX4IO_P_SETUP_ARMING_IO_ARM_OK;
  	}
  
  	if (control_mode.flag_external_manual_override_ok) {
  		set |= PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK;
  
  	} else {
  		clear |= PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK;
  	}
  
  	return io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, clear, set);
  }
  
  int
  PX4IO::disable_rc_handling()
  {
  	_rc_handling_disabled = true;
  	return io_disable_rc_handling();
  }
  
  int
  PX4IO::io_disable_rc_handling()
  {
  	uint16_t set = PX4IO_P_SETUP_ARMING_RC_HANDLING_DISABLED;
  	uint16_t clear = 0;
  
  	return io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, clear, set);
  }
  
  int
  PX4IO::io_set_rc_config()
  {
  	unsigned offset = 0;
  	int input_map[_max_rc_input];
  	int32_t ichan;
  	int ret = OK;
  
  	/*
  	 * Generate the input channel -> control channel mapping table;
  	 * assign RC_MAP_ROLL/PITCH/YAW/THROTTLE to the canonical
  	 * controls.
  	 */
  
  	/* fill the mapping with an error condition triggering value */
  	for (unsigned i = 0; i < _max_rc_input; i++)
  		input_map[i] = UINT8_MAX;
  
  	/*
  	 * NOTE: The indices for mapped channels are 1-based
  	 *       for compatibility reasons with existing
  	 *       autopilots / GCS'.
  	 */
  	param_get(param_find("RC_MAP_ROLL"), &ichan);
  
  	if ((ichan >= 0) && (ichan < (int)_max_rc_input))
  		input_map[ichan - 1] = 0;
  
  	param_get(param_find("RC_MAP_PITCH"), &ichan);
  
  	if ((ichan >= 0) && (ichan < (int)_max_rc_input))
  		input_map[ichan - 1] = 1;
  
  	param_get(param_find("RC_MAP_YAW"), &ichan);
  
  	if ((ichan >= 0) && (ichan < (int)_max_rc_input))
  		input_map[ichan - 1] = 2;
  
  	param_get(param_find("RC_MAP_THROTTLE"), &ichan);
  
  	if ((ichan >= 0) && (ichan < (int)_max_rc_input))
  		input_map[ichan - 1] = 3;
  
  	param_get(param_find("RC_MAP_MODE_SW"), &ichan);
  
  	if ((ichan >= 0) && (ichan < (int)_max_rc_input))
  		input_map[ichan - 1] = 4;
  
  	/*
  	 * Iterate all possible RC inputs.
  	 */
  	for (unsigned i = 0; i < _max_rc_input; i++) {
  		uint16_t regs[PX4IO_P_RC_CONFIG_STRIDE];
  		char pname[16];
  		float fval;
  
  		/*
  		 * RC params are floats, but do only
  		 * contain integer values. Do not scale
  		 * or cast them, let the auto-typeconversion
  		 * do its job here.
  		 * Channels: 500 - 2500
  		 * Inverted flag: -1 (inverted) or 1 (normal)
  		 */
  
  		sprintf(pname, "RC%d_MIN", i + 1);
  		param_get(param_find(pname), &fval);
  		regs[PX4IO_P_RC_CONFIG_MIN] = fval;
  
  		sprintf(pname, "RC%d_TRIM", i + 1);
  		param_get(param_find(pname), &fval);
  		regs[PX4IO_P_RC_CONFIG_CENTER] = fval;
  
  		sprintf(pname, "RC%d_MAX", i + 1);
  		param_get(param_find(pname), &fval);
  		regs[PX4IO_P_RC_CONFIG_MAX] = fval;
  
  		sprintf(pname, "RC%d_DZ", i + 1);
  		param_get(param_find(pname), &fval);
  		regs[PX4IO_P_RC_CONFIG_DEADZONE] = fval;
  
  		regs[PX4IO_P_RC_CONFIG_ASSIGNMENT] = input_map[i];
  
  		regs[PX4IO_P_RC_CONFIG_OPTIONS] = PX4IO_P_RC_CONFIG_OPTIONS_ENABLED;
  		sprintf(pname, "RC%d_REV", i + 1);
  		param_get(param_find(pname), &fval);
  
  		/*
  		 * This has been taken for the sake of compatibility
  		 * with APM's setup / mission planner: normal: 1,
  		 * inverted: -1
  		 */
  		if (fval < 0) {
  			regs[PX4IO_P_RC_CONFIG_OPTIONS] |= PX4IO_P_RC_CONFIG_OPTIONS_REVERSE;
  		}
  
  		/* send channel config to IO */
  		ret = io_reg_set(PX4IO_PAGE_RC_CONFIG, offset, regs, PX4IO_P_RC_CONFIG_STRIDE);
  
  		if (ret != OK) {
  			log("rc config upload failed");
  			break;
  		}
  
  		/* check the IO initialisation flag */
  		if (!(io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_FLAGS) & PX4IO_P_STATUS_FLAGS_INIT_OK)) {
  			log("config for RC%d rejected by IO", i + 1);
  			break;
  		}
  
  		offset += PX4IO_P_RC_CONFIG_STRIDE;
  	}
  
  	return ret;
  }
  
  int
  PX4IO::io_handle_status(uint16_t status)
  {
  	int ret = 1;
  	/**
  	 * WARNING: This section handles in-air resets.
  	 */
  
  	/* check for IO reset - force it back to armed if necessary */
  	if (_status & PX4IO_P_STATUS_FLAGS_SAFETY_OFF && !(status & PX4IO_P_STATUS_FLAGS_SAFETY_OFF)
  	    && !(status & PX4IO_P_STATUS_FLAGS_ARM_SYNC)) {
  		/* set the arming flag */
  		ret = io_reg_modify(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_FLAGS, 0, PX4IO_P_STATUS_FLAGS_SAFETY_OFF | PX4IO_P_STATUS_FLAGS_ARM_SYNC);
  
  		/* set new status */
  		_status = status;
  		_status &= PX4IO_P_STATUS_FLAGS_SAFETY_OFF;
  
  	} else if (!(_status & PX4IO_P_STATUS_FLAGS_ARM_SYNC)) {
  
  		/* set the sync flag */
  		ret = io_reg_modify(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_FLAGS, 0, PX4IO_P_STATUS_FLAGS_ARM_SYNC);
  		/* set new status */
  		_status = status;
  
  	} else {
  		ret = 0;
  
  		/* set new status */
  		_status = status;
  	}
  
  	/**
  	 * Get and handle the safety status
  	 */
  	struct safety_s safety;
  	safety.timestamp = hrt_absolute_time();
  
  	if (status & PX4IO_P_STATUS_FLAGS_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 > 0) {
  		orb_publish(ORB_ID(safety), _to_safety, &safety);
  
  	} else {
  		_to_safety = orb_advertise(ORB_ID(safety), &safety);
  	}
  
  	return ret;
  }
  
  void
  PX4IO::dsm_bind_ioctl(int dsmMode)
  {
  	if (!(_status & PX4IO_P_STATUS_FLAGS_SAFETY_OFF)) {
  		mavlink_log_info(_mavlink_fd, "[IO] 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_fd, "binding failed.");
  
  	} else {
  		mavlink_log_info(_mavlink_fd, "[IO] system armed, bind request rejected");
  	}
  }
  
  
  int
  PX4IO::io_handle_alarms(uint16_t alarms)
  {
  
  	/* XXX handle alarms */
  
  
  	/* set new alarms state */
  	_alarms = alarms;
  
  	return 0;
  }
  
  void
  PX4IO::io_handle_battery(uint16_t vbatt, uint16_t ibatt)
  {
  	/* only publish if battery has a valid minimum voltage */
  	if (vbatt <= 4900) {
  		return;
  	}
  
  	battery_status_s	battery_status;
  	battery_status.timestamp = hrt_absolute_time();
  
  	/* voltage is scaled to mV */
  	battery_status.voltage_v = vbatt / 1000.0f;
  	battery_status.voltage_filtered_v = vbatt / 1000.0f;
  
  	/*
  	  ibatt contains the raw ADC count, as 12 bit ADC
  	  value, with full range being 3.3v
  	*/
  	battery_status.current_a = ibatt * (3.3f / 4096.0f) * _battery_amp_per_volt;
  	battery_status.current_a += _battery_amp_bias;
  
  	/*
  	  integrate battery over time to get total mAh used
  	*/
  	if (_battery_last_timestamp != 0) {
  		_battery_mamphour_total += battery_status.current_a *
  					   (battery_status.timestamp - _battery_last_timestamp) * 1.0e-3f / 3600;
  	}
  
  	battery_status.discharged_mah = _battery_mamphour_total;
  	_battery_last_timestamp = battery_status.timestamp;
  
  	/* the announced battery status would conflict with the simulated battery status in HIL */
  	if (!(_pub_blocked)) {
  		/* lazily publish the battery voltage */
  		if (_to_battery > 0) {
  			orb_publish(ORB_ID(battery_status), _to_battery, &battery_status);
  
  		} else {
  			_to_battery = orb_advertise(ORB_ID(battery_status), &battery_status);
  		}
  	}
  }
  
  void
  PX4IO::io_handle_vservo(uint16_t vservo, uint16_t vrssi)
  {
  	_servorail_status.timestamp = hrt_absolute_time();
  
  	/* voltage is scaled to mV */
  	_servorail_status.voltage_v = vservo * 0.001f;
  	_servorail_status.rssi_v    = vrssi * 0.001f;
  
  	/* lazily publish the servorail voltages */
  	if (_to_servorail > 0) {
  		orb_publish(ORB_ID(servorail_status), _to_servorail, &_servorail_status);
  
  	} else {
  		_to_servorail = orb_advertise(ORB_ID(servorail_status), &_servorail_status);
  	}
  }
  
  int
  PX4IO::io_get_status()
  {
  	uint16_t	regs[6];
  	int		ret;
  
  	/* get
  	 * STATUS_FLAGS, STATUS_ALARMS, STATUS_VBATT, STATUS_IBATT,
  	 * STATUS_VSERVO, STATUS_VRSSI, STATUS_PRSSI
  	 * in that order */
  	ret = io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_FLAGS, &regs[0], sizeof(regs) / sizeof(regs[0]));
  
  	if (ret != OK)
  		return ret;
  
  	io_handle_status(regs[0]);
  	io_handle_alarms(regs[1]);
  
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V1
  	io_handle_battery(regs[2], regs[3]);
  #endif
  
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V2
  	io_handle_vservo(regs[4], regs[5]);
  #endif
  
  	return ret;
  }
  
  int
  PX4IO::io_get_raw_rc_input(rc_input_values &input_rc)
  {
  	uint32_t channel_count;
  	int	ret;
  
  	/* we don't have the status bits, so input_source has to be set elsewhere */
  	input_rc.input_source = RC_INPUT_SOURCE_UNKNOWN;
  
  	const unsigned prolog = (PX4IO_P_RAW_RC_BASE - PX4IO_P_RAW_RC_COUNT);
  	uint16_t regs[RC_INPUT_MAX_CHANNELS + prolog];
  
  	/*
  	 * Read the channel count and the first 9 channels.
  	 *
  	 * This should be the common case (9 channel R/C control being a reasonable upper bound).
  	 */
  	ret = io_reg_get(PX4IO_PAGE_RAW_RC_INPUT, PX4IO_P_RAW_RC_COUNT, &regs[0], prolog + 9);
  
  	if (ret != OK)
  		return ret;
  
  	/*
  	 * Get the channel count any any extra channels. This is no more expensive than reading the
  	 * channel count once.
  	 */
  	channel_count = regs[PX4IO_P_RAW_RC_COUNT];
  
  	/* limit the channel count */
  	if (channel_count > RC_INPUT_MAX_CHANNELS) {
  		channel_count = RC_INPUT_MAX_CHANNELS;
  	}
  
  	/* count channel count changes to identify signal integrity issues */
  	if (channel_count != _rc_chan_count) {
  		perf_count(_perf_chan_count);
  	}
  
  	_rc_chan_count = channel_count;
  
  	input_rc.timestamp_publication = hrt_absolute_time();
  
  	input_rc.rc_ppm_frame_length = regs[PX4IO_P_RAW_RC_DATA];
  	input_rc.rssi = regs[PX4IO_P_RAW_RC_NRSSI];
  	input_rc.rc_failsafe = (regs[PX4IO_P_RAW_RC_FLAGS] & PX4IO_P_RAW_RC_FLAGS_FAILSAFE);
  	input_rc.rc_lost = !(regs[PX4IO_P_RAW_RC_FLAGS] & PX4IO_P_RAW_RC_FLAGS_RC_OK);
  	input_rc.rc_lost_frame_count = regs[PX4IO_P_RAW_LOST_FRAME_COUNT];
  	input_rc.rc_total_frame_count = regs[PX4IO_P_RAW_FRAME_COUNT];
  	input_rc.channel_count = channel_count;
  
  	/* rc_lost has to be set before the call to this function */
  	if (!input_rc.rc_lost && !input_rc.rc_failsafe) {
  		_rc_last_valid = input_rc.timestamp_publication;
  	}
  
  	input_rc.timestamp_last_signal = _rc_last_valid;
  
  	/* FIELDS NOT SET HERE */
  	/* input_rc.input_source is set after this call XXX we might want to mirror the flags in the RC struct */
  
  	if (channel_count > 9) {
  		ret = io_reg_get(PX4IO_PAGE_RAW_RC_INPUT, PX4IO_P_RAW_RC_BASE + 9, &regs[prolog + 9], channel_count - 9);
  
  		if (ret != OK)
  			return ret;
  	}
  
  	/* last thing set are the actual channel values as 16 bit values */
  	for (unsigned i = 0; i < channel_count; i++) {
  		input_rc.values[i] = regs[prolog + i];
  	}
  
  	return ret;
  }
  
  int
  PX4IO::io_publish_raw_rc()
  {
  
  	/* fetch values from IO */
  	rc_input_values	rc_val;
  
  	/* set the RC status flag ORDER MATTERS! */
  	rc_val.rc_lost = !(_status & PX4IO_P_STATUS_FLAGS_RC_OK);
  
  	int ret = io_get_raw_rc_input(rc_val);
  
  	if (ret != OK)
  		return ret;
  
  	/* sort out the source of the values */
  	if (_status & PX4IO_P_STATUS_FLAGS_RC_PPM) {
  		rc_val.input_source = RC_INPUT_SOURCE_PX4IO_PPM;
  
  	} else if (_status & PX4IO_P_STATUS_FLAGS_RC_DSM) {
  		rc_val.input_source = RC_INPUT_SOURCE_PX4IO_SPEKTRUM;
  
  	} else if (_status & PX4IO_P_STATUS_FLAGS_RC_SBUS) {
  		rc_val.input_source = RC_INPUT_SOURCE_PX4IO_SBUS;
  
  	} else if (_status & PX4IO_P_STATUS_FLAGS_RC_ST24) {
  		rc_val.input_source = RC_INPUT_SOURCE_PX4IO_ST24;
  
  	} else {
  		rc_val.input_source = RC_INPUT_SOURCE_UNKNOWN;
  
  		/* only keep publishing RC input if we ever got a valid input */
  		if (_rc_last_valid == 0) {
  			/* we have never seen valid RC signals, abort */
  			return OK;
  		}
  	}
  
  	/* lazily advertise on first publication */
  	if (_to_input_rc == 0) {
  		_to_input_rc = orb_advertise(ORB_ID(input_rc), &rc_val);
  
  	} else {
  		orb_publish(ORB_ID(input_rc), _to_input_rc, &rc_val);
  	}
  
  	return OK;
  }
  
  int
  PX4IO::io_publish_pwm_outputs()
  {
  	/* if no FMU comms(!) just don't publish */
  	if (!(_status & PX4IO_P_STATUS_FLAGS_FMU_OK))
  		return OK;
  
  	/* data we are going to fetch */
  	actuator_outputs_s outputs;
  	outputs.timestamp = hrt_absolute_time();
  
  	/* get servo values from IO */
  	uint16_t ctl[_max_actuators];
  	int ret = io_reg_get(PX4IO_PAGE_SERVOS, 0, ctl, _max_actuators);
  
  	if (ret != OK)
  		return ret;
  
  	/* convert from register format to float */
  	for (unsigned i = 0; i < _max_actuators; i++)
  		outputs.output[i] = ctl[i];
  
  	outputs.noutputs = _max_actuators;
  
  	/* lazily advertise on first publication */
  	if (_to_outputs == 0) {
  		_to_outputs = orb_advertise((_primary_pwm_device ?
  					     ORB_ID_VEHICLE_CONTROLS :
  					     ORB_ID(actuator_outputs_1)),
  					    &outputs);
  
  	} else {
  		orb_publish((_primary_pwm_device ?
  			     ORB_ID_VEHICLE_CONTROLS :
  			     ORB_ID(actuator_outputs_1)),
  			    _to_outputs,
  			    &outputs);
  	}
  
  	return OK;
  }
  
  int
  PX4IO::io_reg_set(uint8_t page, uint8_t offset, const uint16_t *values, unsigned num_values)
  {
  	/* range check the transfer */
  	if (num_values > ((_max_transfer) / sizeof(*values))) {
  		debug("io_reg_set: too many registers (%u, max %u)", num_values, _max_transfer / 2);
  		return -EINVAL;
  	}
  
  	int ret =  _interface->write((page << 8) | offset, (void *)values, num_values);
  
  	if (ret != (int)num_values) {
  		debug("io_reg_set(%u,%u,%u): error %d", page, offset, num_values, ret);
  		return -1;
  	}
  
  	return OK;
  }
  
  int
  PX4IO::io_reg_set(uint8_t page, uint8_t offset, uint16_t value)
  {
  	return io_reg_set(page, offset, &value, 1);
  }
  
  int
  PX4IO::io_reg_get(uint8_t page, uint8_t offset, uint16_t *values, unsigned num_values)
  {
  	/* range check the transfer */
  	if (num_values > ((_max_transfer) / sizeof(*values))) {
  		debug("io_reg_get: too many registers (%u, max %u)", num_values, _max_transfer / 2);
  		return -EINVAL;
  	}
  
  	int ret = _interface->read((page << 8) | offset, reinterpret_cast<void *>(values), num_values);
  
  	if (ret != (int)num_values) {
  		debug("io_reg_get(%u,%u,%u): data error %d", page, offset, num_values, ret);
  		return -1;
  	}
  
  	return OK;
  }
  
  uint32_t
  PX4IO::io_reg_get(uint8_t page, uint8_t offset)
  {
  	uint16_t value;
  
  	if (io_reg_get(page, offset, &value, 1) != OK)
  		return _io_reg_get_error;
  
  	return value;
  }
  
  int
  PX4IO::io_reg_modify(uint8_t page, uint8_t offset, uint16_t clearbits, uint16_t setbits)
  {
  	int ret;
  	uint16_t value;
  
  	ret = io_reg_get(page, offset, &value, 1);
  
  	if (ret != OK)
  		return ret;
  
  	value &= ~clearbits;
  	value |= setbits;
  
  	return io_reg_set(page, offset, value);
  }
  
  int
  PX4IO::print_debug()
  {
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V2
  	int io_fd = -1;
  
  	if (io_fd < 0) {
  		io_fd = ::open("/dev/ttyS0", O_RDONLY | O_NONBLOCK | O_NOCTTY);
  	}
  
  	/* read IO's output */
  	if (io_fd > 0) {
  		pollfd fds[1];
  		fds[0].fd = io_fd;
  		fds[0].events = POLLIN;
  
  		usleep(500);
  		int pret = ::poll(fds, sizeof(fds) / sizeof(fds[0]), 0);
  
  		if (pret > 0) {
  			int count;
  			char buf[65];
  
  			do {
  				count = ::read(io_fd, buf, sizeof(buf) - 1);
  
  				if (count > 0) {
  					/* enforce null termination */
  					buf[count] = '\0';
  					warnx("IO CONSOLE: %s", buf);
  				}
  
  			} while (count > 0);
  		}
  
  		::close(io_fd);
  		return 0;
  	}
  
  #endif
  	return 1;
  
  }
  
  int
  PX4IO::mixer_send(const char *buf, unsigned buflen, unsigned retries)
  {
  	/* get debug level */
  	int debuglevel = io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_SET_DEBUG);
  
  	uint8_t	frame[_max_transfer];
  
  	do {
  
  		px4io_mixdata *msg = (px4io_mixdata *)&frame[0];
  		unsigned max_len = _max_transfer - sizeof(px4io_mixdata);
  
  		msg->f2i_mixer_magic = F2I_MIXER_MAGIC;
  		msg->action = F2I_MIXER_ACTION_RESET;
  
  		do {
  			unsigned count = buflen;
  
  			if (count > max_len)
  				count = max_len;
  
  			if (count > 0) {
  				memcpy(&msg->text[0], buf, count);
  				buf += count;
  				buflen -= count;
  
  			} else {
  				continue;
  			}
  
  			/*
  			 * We have to send an even number of bytes.  This
  			 * will only happen on the very last transfer of a
  			 * mixer, and we are guaranteed that there will be
  			 * space left to round up as _max_transfer will be
  			 * even.
  			 */
  			unsigned total_len = sizeof(px4io_mixdata) + count;
  
  			if (total_len % 2) {
  				msg->text[count] = '\0';
  				total_len++;
  			}
  
  			int ret;
  
  			for (int i = 0; i < 30; i++) {
  				/* failed, but give it a 2nd shot */
  				ret = io_reg_set(PX4IO_PAGE_MIXERLOAD, 0, (uint16_t *)frame, total_len / 2);
  
  				if (ret) {
  					usleep(333);
  				} else {
  					break;
  				}
  			}
  
  			/* print mixer chunk */
  			if (debuglevel > 5 || ret) {
  
  				warnx("fmu sent: \"%s\"", msg->text);
  
  				/* read IO's output */
  				print_debug();
  			}
  
  			if (ret) {
  				log("mixer send error %d", ret);
  				return ret;
  			}
  
  			msg->action = F2I_MIXER_ACTION_APPEND;
  
  		} while (buflen > 0);
  
  		/* ensure a closing newline */
  		msg->text[0] = '\n';
  		msg->text[1] = '\0';
  
  		int ret;
  
  		for (int i = 0; i < 30; i++) {
  			/* failed, but give it a 2nd shot */
  			ret = io_reg_set(PX4IO_PAGE_MIXERLOAD, 0, (uint16_t *)frame, (sizeof(px4io_mixdata) + 2) / 2);
  
  			if (ret) {
  				usleep(333);
  			} else {
  				break;
  			}
  		}
  
  		if (ret)
  			return ret;
  
  		retries--;
  
  		log("mixer sent");
  
  	} while (retries > 0 && (!(io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_FLAGS) & PX4IO_P_STATUS_FLAGS_MIXER_OK)));
  
  	/* check for the mixer-OK flag */
  	if (io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_FLAGS) & PX4IO_P_STATUS_FLAGS_MIXER_OK) {
  		mavlink_log_info(_mavlink_fd, "[IO] mixer upload ok");
  		return 0;
  	}
  
  	log("mixer rejected by IO");
  	mavlink_log_info(_mavlink_fd, "[IO] mixer upload fail");
  
  	/* load must have failed for some reason */
  	return -EINVAL;
  }
  
  void
  PX4IO::print_status(bool extended_status)
  {
  	/* basic configuration */
  	printf("protocol %u hardware %u bootloader %u buffer %uB crc 0x%04x%04x\n",
  	       io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_PROTOCOL_VERSION),
  	       io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_HARDWARE_VERSION),
  	       io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_BOOTLOADER_VERSION),
  	       io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_MAX_TRANSFER),
  	       io_reg_get(PX4IO_PAGE_SETUP,  PX4IO_P_SETUP_CRC),
  	       io_reg_get(PX4IO_PAGE_SETUP,  PX4IO_P_SETUP_CRC+1));
  	printf("%u controls %u actuators %u R/C inputs %u analog inputs %u relays\n",
  	       io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_CONTROL_COUNT),
  	       io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_ACTUATOR_COUNT),
  	       io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_RC_INPUT_COUNT),
  	       io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_ADC_INPUT_COUNT),
  	       io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_RELAY_COUNT));
  
  	/* status */
  	printf("%u bytes free\n",
  	       io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_FREEMEM));
  	uint16_t flags = io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_FLAGS);
  	uint16_t io_status_flags = flags;
  	printf("status 0x%04x%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
  	       flags,
  	       ((flags & PX4IO_P_STATUS_FLAGS_OUTPUTS_ARMED) ? " OUTPUTS_ARMED" : ""),
  	       ((flags & PX4IO_P_STATUS_FLAGS_SAFETY_OFF) ? " SAFETY_OFF" : " SAFETY_SAFE"),
  	       ((flags & PX4IO_P_STATUS_FLAGS_OVERRIDE) ? " OVERRIDE" : ""),
  	       ((flags & PX4IO_P_STATUS_FLAGS_RC_OK)    ? " RC_OK" : " RC_FAIL"),
  	       ((flags & PX4IO_P_STATUS_FLAGS_RC_PPM)   ? " PPM" : ""),
  	       ((flags & PX4IO_P_STATUS_FLAGS_RC_DSM)   ? " DSM" : ""),
  	       ((flags & PX4IO_P_STATUS_FLAGS_RC_ST24)   ? " ST24" : ""),
  	       ((flags & PX4IO_P_STATUS_FLAGS_RC_SBUS)  ? " SBUS" : ""),
  	       ((flags & PX4IO_P_STATUS_FLAGS_FMU_OK)   ? " FMU_OK" : " FMU_FAIL"),
  	       ((flags & PX4IO_P_STATUS_FLAGS_RAW_PWM)  ? " RAW_PWM_PASSTHROUGH" : ""),
  	       ((flags & PX4IO_P_STATUS_FLAGS_MIXER_OK) ? " MIXER_OK" : " MIXER_FAIL"),
  	       ((flags & PX4IO_P_STATUS_FLAGS_ARM_SYNC) ? " ARM_SYNC" : " ARM_NO_SYNC"),
  	       ((flags & PX4IO_P_STATUS_FLAGS_INIT_OK)  ? " INIT_OK" : " INIT_FAIL"),
  	       ((flags & PX4IO_P_STATUS_FLAGS_FAILSAFE)  ? " FAILSAFE" : ""));
  	uint16_t alarms = io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_ALARMS);
  	printf("alarms 0x%04x%s%s%s%s%s%s%s%s\n",
  	       alarms,
  	       ((alarms & PX4IO_P_STATUS_ALARMS_VBATT_LOW)     ? " VBATT_LOW" : ""),
  	       ((alarms & PX4IO_P_STATUS_ALARMS_TEMPERATURE)   ? " TEMPERATURE" : ""),
  	       ((alarms & PX4IO_P_STATUS_ALARMS_SERVO_CURRENT) ? " SERVO_CURRENT" : ""),
  	       ((alarms & PX4IO_P_STATUS_ALARMS_ACC_CURRENT)   ? " ACC_CURRENT" : ""),
  	       ((alarms & PX4IO_P_STATUS_ALARMS_FMU_LOST)      ? " FMU_LOST" : ""),
  	       ((alarms & PX4IO_P_STATUS_ALARMS_RC_LOST)       ? " RC_LOST" : ""),
  	       ((alarms & PX4IO_P_STATUS_ALARMS_PWM_ERROR)     ? " PWM_ERROR" : ""),
  	       ((alarms & PX4IO_P_STATUS_ALARMS_VSERVO_FAULT)  ? " VSERVO_FAULT" : ""));
  	/* now clear alarms */
  	io_reg_set(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_ALARMS, 0xFFFF);
  
  	if (_hardware == 1) {
  		printf("vbatt mV %u ibatt mV %u vbatt scale %u\n",
  		       io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_VBATT),
  		       io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_IBATT),
  		       io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_VBATT_SCALE));
  		printf("amp_per_volt %.3f amp_offset %.3f mAh discharged %.3f\n",
  		       (double)_battery_amp_per_volt,
  		       (double)_battery_amp_bias,
  		       (double)_battery_mamphour_total);
  
  	} else if (_hardware == 2) {
  		printf("vservo %u mV vservo scale %u\n",
  		       io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_VSERVO),
  		       io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_VSERVO_SCALE));
  		printf("vrssi %u\n", io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_VRSSI));
  	}
  
  	printf("actuators");
  
  	for (unsigned i = 0; i < _max_actuators; i++)
  		printf(" %hi", int16_t(io_reg_get(PX4IO_PAGE_ACTUATORS, i)));
  
  	printf("\n");
  	printf("servos");
  
  	for (unsigned i = 0; i < _max_actuators; i++)
  		printf(" %u", io_reg_get(PX4IO_PAGE_SERVOS, i));
  
  	printf("\n");
  	uint16_t raw_inputs = io_reg_get(PX4IO_PAGE_RAW_RC_INPUT, PX4IO_P_RAW_RC_COUNT);
  	printf("%d raw R/C inputs", raw_inputs);
  
  	for (unsigned i = 0; i < raw_inputs; i++)
  		printf(" %u", io_reg_get(PX4IO_PAGE_RAW_RC_INPUT, PX4IO_P_RAW_RC_BASE + i));
  
  	printf("\n");
  
  	flags = io_reg_get(PX4IO_PAGE_RAW_RC_INPUT, PX4IO_P_RAW_RC_FLAGS);
  	printf("R/C flags: 0x%04x%s%s%s%s%s\n", flags,
  		(((io_status_flags & PX4IO_P_STATUS_FLAGS_RC_DSM) && (!(flags & PX4IO_P_RAW_RC_FLAGS_RC_DSM11))) ? " DSM10" : ""),
  		(((io_status_flags & PX4IO_P_STATUS_FLAGS_RC_DSM) && (flags & PX4IO_P_RAW_RC_FLAGS_RC_DSM11)) ? " DSM11" : ""),
  		((flags & PX4IO_P_RAW_RC_FLAGS_FRAME_DROP) ? " FRAME_DROP" : ""),
  		((flags & PX4IO_P_RAW_RC_FLAGS_FAILSAFE) ? " FAILSAFE" : ""),
  		((flags & PX4IO_P_RAW_RC_FLAGS_MAPPING_OK) ? " MAPPING_OK" : "")
  	       );
  
  	if ((io_status_flags & PX4IO_P_STATUS_FLAGS_RC_PPM)) {
  		int frame_len = io_reg_get(PX4IO_PAGE_RAW_RC_INPUT, PX4IO_P_RAW_RC_DATA);
  		printf("RC data (PPM frame len) %u us\n", frame_len);
  
  		if ((frame_len - raw_inputs * 2000 - 3000) < 0) {
  			printf("WARNING  WARNING  WARNING! This RC receiver does not allow safe frame detection.\n");
  		}
  	}
  
  	uint16_t mapped_inputs = io_reg_get(PX4IO_PAGE_RC_INPUT, PX4IO_P_RC_VALID);
  	printf("mapped R/C inputs 0x%04x", mapped_inputs);
  
  	for (unsigned i = 0; i < _max_rc_input; i++) {
  		if (mapped_inputs & (1 << i))
  			printf(" %u:%d", i, REG_TO_SIGNED(io_reg_get(PX4IO_PAGE_RC_INPUT, PX4IO_P_RC_BASE + i)));
  	}
  
  	printf("\n");
  	uint16_t adc_inputs = io_reg_get(PX4IO_PAGE_CONFIG, PX4IO_P_CONFIG_ADC_INPUT_COUNT);
  	printf("ADC inputs");
  
  	for (unsigned i = 0; i < adc_inputs; i++)
  		printf(" %u", io_reg_get(PX4IO_PAGE_RAW_ADC_INPUT, i));
  
  	printf("\n");
  
  	/* setup and state */
  	uint16_t features = io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES);
  	printf("features 0x%04x%s%s%s%s\n", features,
  		((features & PX4IO_P_SETUP_FEATURES_SBUS1_OUT) ? " S.BUS1_OUT" : ""),
  		((features & PX4IO_P_SETUP_FEATURES_SBUS2_OUT) ? " S.BUS2_OUT" : ""),
  		((features & PX4IO_P_SETUP_FEATURES_PWM_RSSI) ? " RSSI_PWM" : ""),
  		((features & PX4IO_P_SETUP_FEATURES_ADC_RSSI) ? " RSSI_ADC" : "")
  		);
  	uint16_t arming = io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING);
  	printf("arming 0x%04x%s%s%s%s%s%s%s%s\n",
  	       arming,
  	       ((arming & PX4IO_P_SETUP_ARMING_FMU_ARMED)		? " FMU_ARMED" : " FMU_DISARMED"),
  	       ((arming & PX4IO_P_SETUP_ARMING_IO_ARM_OK)		? " IO_ARM_OK" : " IO_ARM_DENIED"),
  	       ((arming & PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK)	? " MANUAL_OVERRIDE_OK" : ""),
  	       ((arming & PX4IO_P_SETUP_ARMING_FAILSAFE_CUSTOM)		? " FAILSAFE_CUSTOM" : ""),
  	       ((arming & PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK)	? " INAIR_RESTART_OK" : ""),
  	       ((arming & PX4IO_P_SETUP_ARMING_ALWAYS_PWM_ENABLE)	? " ALWAYS_PWM_ENABLE" : ""),
  	       ((arming & PX4IO_P_SETUP_ARMING_LOCKDOWN)		? " LOCKDOWN" : ""),
  	       ((arming & PX4IO_P_SETUP_ARMING_FORCE_FAILSAFE)		? " FORCE_FAILSAFE" : ""),
  	       ((arming & PX4IO_P_SETUP_ARMING_TERMINATION_FAILSAFE) ? " TERM_FAILSAFE" : "")
  	       );
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V1
  	printf("rates 0x%04x default %u alt %u relays 0x%04x\n",
  	       io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_PWM_RATES),
  	       io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_PWM_DEFAULTRATE),
  	       io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_PWM_ALTRATE),
  	       io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_RELAYS));
  #endif
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V2
  	printf("rates 0x%04x default %u alt %u\n",
  	       io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_PWM_RATES),
  	       io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_PWM_DEFAULTRATE),
  	       io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_PWM_ALTRATE));
  #endif
  	printf("debuglevel %u\n", io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_SET_DEBUG));
  	for (unsigned group = 0; group < 4; group++) {
  		printf("controls %u:", group);
  
  		for (unsigned i = 0; i < _max_controls; i++)
  			printf(" %d", (int16_t) io_reg_get(PX4IO_PAGE_CONTROLS, group * PX4IO_PROTOCOL_MAX_CONTROL_COUNT + i));
  
  		printf("\n");
  	}
  
  	if (extended_status) {
  		for (unsigned i = 0; i < _max_rc_input; i++) {
  			unsigned base = PX4IO_P_RC_CONFIG_STRIDE * i;
  			uint16_t options = io_reg_get(PX4IO_PAGE_RC_CONFIG, base + PX4IO_P_RC_CONFIG_OPTIONS);
  			printf("input %u min %u center %u max %u deadzone %u assigned %u options 0x%04x%s%s\n",
  			       i,
  			       io_reg_get(PX4IO_PAGE_RC_CONFIG, base + PX4IO_P_RC_CONFIG_MIN),
  			       io_reg_get(PX4IO_PAGE_RC_CONFIG, base + PX4IO_P_RC_CONFIG_CENTER),
  			       io_reg_get(PX4IO_PAGE_RC_CONFIG, base + PX4IO_P_RC_CONFIG_MAX),
  			       io_reg_get(PX4IO_PAGE_RC_CONFIG, base + PX4IO_P_RC_CONFIG_DEADZONE),
  			       io_reg_get(PX4IO_PAGE_RC_CONFIG, base + PX4IO_P_RC_CONFIG_ASSIGNMENT),
  			       options,
  			       ((options & PX4IO_P_RC_CONFIG_OPTIONS_ENABLED) ? " ENABLED" : ""),
  			       ((options & PX4IO_P_RC_CONFIG_OPTIONS_REVERSE) ? " REVERSED" : ""));
  		}
  	}
  
  	printf("failsafe");
  
  	for (unsigned i = 0; i < _max_actuators; i++)
  		printf(" %u", io_reg_get(PX4IO_PAGE_FAILSAFE_PWM, i));
  
  	printf("\ndisarmed values");
  
  	for (unsigned i = 0; i < _max_actuators; i++)
  		printf(" %u", io_reg_get(PX4IO_PAGE_DISARMED_PWM, i));
  
  	printf("\n");
  }
  
  int
  PX4IO::ioctl(file * filep, int cmd, unsigned long arg)
  {
  	int ret = OK;
  
  	/* regular ioctl? */
  	switch (cmd) {
  	case PWM_SERVO_ARM:
  		/* set the 'armed' bit */
  		ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, 0, PX4IO_P_SETUP_ARMING_FMU_ARMED);
  		break;
  
  	case PWM_SERVO_SET_ARM_OK:
  		/* set the 'OK to arm' bit */
  		ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, 0, PX4IO_P_SETUP_ARMING_IO_ARM_OK);
  		break;
  
  	case PWM_SERVO_CLEAR_ARM_OK:
  		/* clear the 'OK to arm' bit */
  		ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, PX4IO_P_SETUP_ARMING_IO_ARM_OK, 0);
  		break;
  
  	case PWM_SERVO_DISARM:
  		/* clear the 'armed' bit */
  		ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, PX4IO_P_SETUP_ARMING_FMU_ARMED, 0);
  		break;
  
  	case PWM_SERVO_GET_DEFAULT_UPDATE_RATE:
  		/* get the default update rate */
  		*(unsigned *)arg = io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_PWM_DEFAULTRATE);
  		break;
  
  	case PWM_SERVO_SET_UPDATE_RATE:
  		/* set the requested alternate rate */
  		ret = io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_PWM_ALTRATE, arg);
  		break;
  
  	case PWM_SERVO_GET_UPDATE_RATE:
  		/* get the alternative update rate */
  		*(unsigned *)arg = io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_PWM_ALTRATE);
  		break;
  
  	case PWM_SERVO_SET_SELECT_UPDATE_RATE: {
  
  			/* blindly clear the PWM update alarm - might be set for some other reason */
  			io_reg_set(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_ALARMS, PX4IO_P_STATUS_ALARMS_PWM_ERROR);
  
  			/* attempt to set the rate map */
  			io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_PWM_RATES, arg);
  
  			/* check that the changes took */
  			uint16_t alarms = io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_ALARMS);
  
  			if (alarms & PX4IO_P_STATUS_ALARMS_PWM_ERROR) {
  				ret = -EINVAL;
  				io_reg_set(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_ALARMS, PX4IO_P_STATUS_ALARMS_PWM_ERROR);
  			}
  
  			break;
  		}
  
  	case PWM_SERVO_GET_SELECT_UPDATE_RATE:
  
  		*(unsigned *)arg = io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_PWM_RATES);
  		break;
  
  	case PWM_SERVO_SET_FAILSAFE_PWM: {
  		struct pwm_output_values* pwm = (struct pwm_output_values*)arg;
  		if (pwm->channel_count > _max_actuators)
  			/* fail with error */
  			return E2BIG;
  
  		/* copy values to registers in IO */
  		ret = io_reg_set(PX4IO_PAGE_FAILSAFE_PWM, 0, pwm->values, pwm->channel_count);
  		break;
  	}
  
  	case PWM_SERVO_GET_FAILSAFE_PWM:
  
  		ret = io_reg_get(PX4IO_PAGE_FAILSAFE_PWM, 0, (uint16_t*)arg, _max_actuators);
  		if (ret != OK) {
  			ret = -EIO;
  		}
  		break;
  
  	case PWM_SERVO_SET_DISARMED_PWM: {
  		struct pwm_output_values* pwm = (struct pwm_output_values*)arg;
  		if (pwm->channel_count > _max_actuators)
  			/* fail with error */
  			return E2BIG;
  
  		/* copy values to registers in IO */
  		ret = io_reg_set(PX4IO_PAGE_DISARMED_PWM, 0, pwm->values, pwm->channel_count);
  		break;
  	}
  
  	case PWM_SERVO_GET_DISARMED_PWM:
  
  		ret = io_reg_get(PX4IO_PAGE_DISARMED_PWM, 0, (uint16_t*)arg, _max_actuators);
  		if (ret != OK) {
  			ret = -EIO;
  		}
  		break;
  
  	case PWM_SERVO_SET_MIN_PWM: {
  		struct pwm_output_values* pwm = (struct pwm_output_values*)arg;
  		if (pwm->channel_count > _max_actuators)
  			/* fail with error */
  			return E2BIG;
  
  		/* copy values to registers in IO */
  		ret = io_reg_set(PX4IO_PAGE_CONTROL_MIN_PWM, 0, pwm->values, pwm->channel_count);
  		break;
  	}
  
  	case PWM_SERVO_GET_MIN_PWM:
  
  		ret = io_reg_get(PX4IO_PAGE_CONTROL_MIN_PWM, 0, (uint16_t*)arg, _max_actuators);
  		if (ret != OK) {
  			ret = -EIO;
  		}
  		break;
  
  	case PWM_SERVO_SET_MAX_PWM: {
  		struct pwm_output_values* pwm = (struct pwm_output_values*)arg;
  		if (pwm->channel_count > _max_actuators)
  			/* fail with error */
  			return E2BIG;
  
  		/* copy values to registers in IO */
  		ret = io_reg_set(PX4IO_PAGE_CONTROL_MAX_PWM, 0, pwm->values, pwm->channel_count);
  		break;
  	}
  
  	case PWM_SERVO_GET_MAX_PWM:
  
  		ret = io_reg_get(PX4IO_PAGE_CONTROL_MAX_PWM, 0, (uint16_t*)arg, _max_actuators);
  		if (ret != OK) {
  			ret = -EIO;
  		}
  		break;
  
  	case PWM_SERVO_GET_COUNT:
  		*(unsigned *)arg = _max_actuators;
  		break;
  
  	case PWM_SERVO_SET_DISABLE_LOCKDOWN:
  		_lockdown_override = arg;
  		break;
  
  	case PWM_SERVO_GET_DISABLE_LOCKDOWN:
  		*(unsigned *)arg = _lockdown_override;
  
  	case PWM_SERVO_SET_FORCE_SAFETY_OFF:
  		/* force safety swith off */
  		ret = io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FORCE_SAFETY_OFF, PX4IO_FORCE_SAFETY_MAGIC);
  		break;
  
  	case PWM_SERVO_SET_FORCE_FAILSAFE:
  		/* force failsafe mode instantly */
  		if (arg == 0) {
  			/* clear force failsafe flag */
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, PX4IO_P_SETUP_ARMING_FORCE_FAILSAFE, 0);
  		} else {
  			/* set force failsafe flag */
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, 0, PX4IO_P_SETUP_ARMING_FORCE_FAILSAFE);
  		}
  		break;
  
  	case PWM_SERVO_SET_TERMINATION_FAILSAFE:
  		/* if failsafe occurs, do not allow the system to recover */
  		if (arg == 0) {
  			/* clear termination failsafe flag */
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, PX4IO_P_SETUP_ARMING_TERMINATION_FAILSAFE, 0);
  		} else {
  			/* set termination failsafe flag */
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, 0, PX4IO_P_SETUP_ARMING_TERMINATION_FAILSAFE);
  		}
  		break;
  
  	case DSM_BIND_START:
  
  		/* only allow DSM2, DSM-X and DSM-X with more than 7 channels */
  		if (arg == DSM2_BIND_PULSES ||
  		    arg == DSMX_BIND_PULSES ||
  		    arg == DSMX8_BIND_PULSES) {
  			io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_DSM, dsm_bind_power_down);
  			usleep(500000);
  			io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_DSM, dsm_bind_set_rx_out);
  			io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_DSM, dsm_bind_power_up);
  			usleep(72000);
  			io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_DSM, dsm_bind_send_pulses | (arg << 4));
  			usleep(50000);
  			io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_DSM, dsm_bind_reinit_uart);
  
  			ret = OK;
  		} else {
  			ret = -EINVAL;
  		}
  		break;
  
  	case DSM_BIND_POWER_UP:
  		io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_DSM, dsm_bind_power_up);
  		break;
  
  	case PWM_SERVO_SET(0) ... PWM_SERVO_SET(PWM_OUTPUT_MAX_CHANNELS - 1): {
  
  			/* TODO: we could go lower for e.g. TurboPWM */
  			unsigned channel = cmd - PWM_SERVO_SET(0);
  
  			if ((channel >= _max_actuators) || (arg < PWM_LOWEST_MIN) || (arg > PWM_HIGHEST_MAX)) {
  				ret = -EINVAL;
  
  			} else {
  				/* send a direct PWM value */
  				ret = io_reg_set(PX4IO_PAGE_DIRECT_PWM, channel, arg);
  			}
  
  			break;
  		}
  
  	case PWM_SERVO_GET(0) ... PWM_SERVO_GET(PWM_OUTPUT_MAX_CHANNELS - 1): {
  
  			unsigned channel = cmd - PWM_SERVO_GET(0);
  
  			if (channel >= _max_actuators) {
  				ret = -EINVAL;
  
  			} else {
  				/* fetch a current PWM value */
  				uint32_t value = io_reg_get(PX4IO_PAGE_SERVOS, channel);
  
  				if (value == _io_reg_get_error) {
  					ret = -EIO;
  
  				} else {
  					*(servo_position_t *)arg = value;
  				}
  			}
  
  			break;
  		}
  
  	case PWM_SERVO_GET_RATEGROUP(0) ... PWM_SERVO_GET_RATEGROUP(PWM_OUTPUT_MAX_CHANNELS - 1): {
  
  			unsigned channel = cmd - PWM_SERVO_GET_RATEGROUP(0);
  
  			*(uint32_t *)arg = io_reg_get(PX4IO_PAGE_PWM_INFO, PX4IO_RATE_MAP_BASE + channel);
  
  			if (*(uint32_t *)arg == _io_reg_get_error)
  				ret = -EIO;
  
  			break;
  		}
  
  	case GPIO_RESET: {
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V1
  			uint32_t bits = (1 << _max_relays) - 1;
  
  			/* don't touch relay1 if it's controlling RX vcc */
  			if (_dsm_vcc_ctl)
  				bits &= ~PX4IO_P_SETUP_RELAYS_POWER1;
  
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_RELAYS, bits, 0);
  #endif
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V2
  			ret = -EINVAL;
  #endif
  			break;
  		}
  
  	case GPIO_SET:
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V1
  		arg &= ((1 << _max_relays) - 1);
  
  		/* don't touch relay1 if it's controlling RX vcc */
  		if (_dsm_vcc_ctl & (arg & PX4IO_P_SETUP_RELAYS_POWER1)) {
  			ret = -EINVAL;
  			break;
  		}
  
  		ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_RELAYS, 0, arg);
  #endif
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V2
  		ret = -EINVAL;
  #endif
  		break;
  
  	case GPIO_CLEAR:
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V1
  		arg &= ((1 << _max_relays) - 1);
  
  		/* don't touch relay1 if it's controlling RX vcc */
  		if (_dsm_vcc_ctl & (arg & PX4IO_P_SETUP_RELAYS_POWER1)) {
  			ret = -EINVAL;
  			break;
  		}
  
  		ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_RELAYS, arg, 0);
  #endif
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V2
  		ret = -EINVAL;
  #endif
  		break;
  
  	case GPIO_GET:
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V1
  		*(uint32_t *)arg = io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_RELAYS);
  
  		if (*(uint32_t *)arg == _io_reg_get_error)
  			ret = -EIO;
  
  #endif
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V2
  		ret = -EINVAL;
  #endif
  		break;
  
  	case MIXERIOCGETOUTPUTCOUNT:
  		*(unsigned *)arg = _max_actuators;
  		break;
  
  	case MIXERIOCRESET:
  		ret = 0;	/* load always resets */
  		break;
  
  	case MIXERIOCLOADBUF: {
  			const char *buf = (const char *)arg;
  			ret = mixer_send(buf, strnlen(buf, 2048));
  			break;
  		}
  
  	case RC_INPUT_GET: {
  			uint16_t status;
  			rc_input_values *rc_val = (rc_input_values *)arg;
  
  			ret = io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_FLAGS, &status, 1);
  
  			if (ret != OK)
  				break;
  
  			/* if no R/C input, don't try to fetch anything */
  			if (!(status & PX4IO_P_STATUS_FLAGS_RC_OK)) {
  				ret = -ENOTCONN;
  				break;
  			}
  
  			/* sort out the source of the values */
  			if (status & PX4IO_P_STATUS_FLAGS_RC_PPM) {
  				rc_val->input_source = RC_INPUT_SOURCE_PX4IO_PPM;
  
  			} else if (status & PX4IO_P_STATUS_FLAGS_RC_DSM) {
  				rc_val->input_source = RC_INPUT_SOURCE_PX4IO_SPEKTRUM;
  
  			} else if (status & PX4IO_P_STATUS_FLAGS_RC_SBUS) {
  				rc_val->input_source = RC_INPUT_SOURCE_PX4IO_SBUS;
  
  			} else if (status & PX4IO_P_STATUS_FLAGS_RC_ST24) {
  				rc_val->input_source = RC_INPUT_SOURCE_PX4IO_ST24;
  
  			} else {
  				rc_val->input_source = RC_INPUT_SOURCE_UNKNOWN;
  			}
  
  			/* read raw R/C input values */
  			ret = io_reg_get(PX4IO_PAGE_RAW_RC_INPUT, PX4IO_P_RAW_RC_BASE, &(rc_val->values[0]), _max_rc_input);
  			break;
  		}
  
  	case PX4IO_SET_DEBUG:
  		/* set the debug level */
  		ret = io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_SET_DEBUG, arg);
  		break;
  
  	case PX4IO_REBOOT_BOOTLOADER:
  		if (system_status() & PX4IO_P_STATUS_FLAGS_SAFETY_OFF)
  			return -EINVAL;
  
  		/* reboot into bootloader - arg must be PX4IO_REBOOT_BL_MAGIC */
  		io_reg_set(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_REBOOT_BL, arg);
  		// we don't expect a reply from this operation
  		ret = OK;
  		break;
  
  	case PX4IO_CHECK_CRC: {
  		/* check IO firmware CRC against passed value */
  		uint32_t io_crc = 0;
  		ret = io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_CRC, (uint16_t *)&io_crc, 2);
  		if (ret != OK)
  			return ret;
  		if (io_crc != arg) {
  			debug("crc mismatch 0x%08x 0x%08x", (unsigned)io_crc, arg);
  			return -EINVAL;
  		}
  		break;
  	}
  
  	case PX4IO_INAIR_RESTART_ENABLE:
  
  		/* set/clear the 'in-air restart' bit */
  		if (arg) {
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, 0, PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK);
  
  		} else {
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK, 0);
  		}
  
  		break;
  
  	case RC_INPUT_ENABLE_RSSI_ANALOG:
  
  		if (arg) {
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, 0, PX4IO_P_SETUP_FEATURES_ADC_RSSI);
  		} else {
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, PX4IO_P_SETUP_FEATURES_ADC_RSSI, 0);
  		}
  
  		break;
  
  	case RC_INPUT_ENABLE_RSSI_PWM:
  
  		if (arg) {
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, 0, PX4IO_P_SETUP_FEATURES_PWM_RSSI);
  		} else {
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, PX4IO_P_SETUP_FEATURES_PWM_RSSI, 0);
  		}
  
  		break;
  
  	case SBUS_SET_PROTO_VERSION:
  
  		if (arg == 1) {
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, 0, PX4IO_P_SETUP_FEATURES_SBUS1_OUT);
  		} else if (arg == 2) {
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, 0, PX4IO_P_SETUP_FEATURES_SBUS2_OUT);
  		} else {
  			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, (PX4IO_P_SETUP_FEATURES_SBUS1_OUT | PX4IO_P_SETUP_FEATURES_SBUS2_OUT), 0);
  		}
  
  		break;
  
  	default:
  		/* see if the parent class can make any use of it */
  		ret = CDev::ioctl(filep, cmd, arg);
  		break;
  	}
  
  	return ret;
  }
  
  ssize_t
  PX4IO::write(file * /*filp*/, const char *buffer, size_t len)
  /* Make it obvious that file * isn't used here */
  {
  	unsigned count = len / 2;
  
  	if (count > _max_actuators)
  		count = _max_actuators;
  
  	if (count > 0) {
  
  		perf_begin(_perf_write);
  		int ret = io_reg_set(PX4IO_PAGE_DIRECT_PWM, 0, (uint16_t *)buffer, count);
  		perf_end(_perf_write);
  
  		if (ret != OK)
  			return ret;
  	}
  
  	return count * 2;
  }
  
  int
  PX4IO::set_update_rate(int rate)
  {
  	int interval_ms = 1000 / rate;
  
  	if (interval_ms < UPDATE_INTERVAL_MIN) {
  		interval_ms = UPDATE_INTERVAL_MIN;
  		warnx("update rate too high, limiting interval to %d ms (%d Hz).", interval_ms, 1000 / interval_ms);
  	}
  
  	if (interval_ms > 100) {
  		interval_ms = 100;
  		warnx("update rate too low, limiting to %d ms (%d Hz).", interval_ms, 1000 / interval_ms);
  	}
  
  	_update_interval = interval_ms;
  	return 0;
  }
  
  void
  PX4IO::set_battery_current_scaling(float amp_per_volt, float amp_bias)
  {
  	_battery_amp_per_volt = amp_per_volt;
  	_battery_amp_bias = amp_bias;
  }
  
  extern "C" __EXPORT int px4io_main(int argc, char *argv[]);
  
  namespace
  {
  
  device::Device *
  get_interface()
  {
  	device::Device *interface = nullptr;
  
  #ifndef CONFIG_ARCH_BOARD_PX4FMU_V1
  
  	/* try for a serial interface */
  	if (PX4IO_serial_interface != nullptr)
  		interface = PX4IO_serial_interface();
  
  	if (interface != nullptr)
  		goto got;
  
  #endif
  
  	/* try for an I2C interface if we haven't got a serial one */
  	if (PX4IO_i2c_interface != nullptr)
  		interface = PX4IO_i2c_interface();
  
  	if (interface != nullptr)
  		goto got;
  
  	errx(1, "cannot alloc interface");
  
  got:
  
  	if (interface->init() != OK) {
  		delete interface;
  		errx(1, "interface init failed");
  	}
  
  	return interface;
  }
  
  void
  start(int argc, char *argv[])
  {
  	if (g_dev != nullptr)
  		errx(0, "already loaded");
  
  	/* allocate the interface */
  	device::Device *interface = get_interface();
  
  	/* create the driver - it will set g_dev */
  	(void)new PX4IO(interface);
  
  	if (g_dev == nullptr) {
  		delete interface;
  		errx(1, "driver alloc failed");
  	}
  
  	bool rc_handling_disabled = false;
  
  	/* disable RC handling on request */
  	if (argc > 1) {
  		if (!strcmp(argv[1], "norc")) {
  
  			rc_handling_disabled = true;
  
  		} else {
  			warnx("unknown argument: %s", argv[1]);
  		}
  	}
  
  	if (OK != g_dev->init(rc_handling_disabled)) {
  		delete g_dev;
  		g_dev = nullptr;
  		errx(1, "driver init failed");
  	}
  
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V1
  	int dsm_vcc_ctl;
  
  	if (param_get(param_find("RC_RL1_DSM_VCC"), &dsm_vcc_ctl) == OK) {
  		if (dsm_vcc_ctl) {
  			g_dev->set_dsm_vcc_ctl(true);
  			g_dev->ioctl(nullptr, DSM_BIND_POWER_UP, 0);
  		}
  	}
  
  #endif
  	exit(0);
  }
  
  void
  detect(int argc, char *argv[])
  {
  	if (g_dev != nullptr)
  		errx(0, "already loaded");
  
  	/* allocate the interface */
  	device::Device *interface = get_interface();
  
  	/* create the driver - it will set g_dev */
  	(void)new PX4IO(interface);
  
  	if (g_dev == nullptr)
  		errx(1, "driver alloc failed");
  
  	int ret = g_dev->detect();
  
  	delete g_dev;
  	g_dev = nullptr;
  
  	if (ret) {
  		/* nonzero, error */
  		exit(1);
  
  	} else {
  		exit(0);
  	}
  }
  
  void
  checkcrc(int argc, char *argv[])
  {
  	bool keep_running = false;
  
  	if (g_dev == nullptr) {
  		/* allocate the interface */
  		device::Device *interface = get_interface();
  
  		/* create the driver - it will set g_dev */
  		(void)new PX4IO(interface);
  
  		if (g_dev == nullptr)
  			errx(1, "driver alloc failed");
  	} else {
  		/* its already running, don't kill the driver */
  		keep_running = true;
  	}
  
  	/*
  	  check IO CRC against CRC of a file
  	 */
  	if (argc < 2) {
  		printf("usage: px4io checkcrc filename\n");
  		exit(1);
  	}
  	int fd = open(argv[1], O_RDONLY);
  	if (fd == -1) {
  		printf("open of %s failed - %d\n", argv[1], errno);
  		exit(1);
  	}
  	const uint32_t app_size_max = 0xf000;
  	uint32_t fw_crc = 0;
  	uint32_t nbytes = 0;
  	while (true) {
  		uint8_t buf[16];
  		int n = read(fd, buf, sizeof(buf));
  		if (n <= 0) break;
  		fw_crc = crc32part(buf, n, fw_crc);
  		nbytes += n;
  	}
  	close(fd);
  	while (nbytes < app_size_max) {
  		uint8_t b = 0xff;
  		fw_crc = crc32part(&b, 1, fw_crc);
  		nbytes++;
  	}
  
  	int ret = g_dev->ioctl(nullptr, PX4IO_CHECK_CRC, fw_crc);
  
  	if (!keep_running) {
  		delete g_dev;
  		g_dev = nullptr;
  	}
  
  	if (ret != OK) {
  		printf("check CRC failed - %d\n", ret);
  		exit(1);
  	}
  	printf("CRCs match\n");
  	exit(0);
  }
  
  void
  bind(int argc, char *argv[])
  {
  	int pulses;
  
  	if (g_dev == nullptr)
  		errx(1, "px4io must be started first");
  
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V1
  
  	if (!g_dev->get_dsm_vcc_ctl())
  		errx(1, "DSM bind feature not enabled");
  
  #endif
  
  	if (argc < 3)
  		errx(0, "needs argument, use dsm2, dsmx or dsmx8");
  
  	if (!strcmp(argv[2], "dsm2"))
  		pulses = DSM2_BIND_PULSES;
  	else if (!strcmp(argv[2], "dsmx"))
  		pulses = DSMX_BIND_PULSES;
  	else if (!strcmp(argv[2], "dsmx8"))
  		pulses = DSMX8_BIND_PULSES;
  	else
  		errx(1, "unknown parameter %s, use dsm2, dsmx or dsmx8", argv[2]);
  	// Test for custom pulse parameter
  	if (argc > 3)
  		pulses = atoi(argv[3]);
  	if (g_dev->system_status() & PX4IO_P_STATUS_FLAGS_SAFETY_OFF)
  		errx(1, "system must not be armed");
  
  #ifdef CONFIG_ARCH_BOARD_PX4FMU_V1
  	warnx("This command will only bind DSM if satellite VCC (red wire) is controlled by relay 1.");
  #endif
  	g_dev->ioctl(nullptr, DSM_BIND_START, pulses);
  
  	exit(0);
  
  }
  
  void
  test(void)
  {
  	int		fd;
  	unsigned	servo_count = 0;
  	unsigned	pwm_value = 1000;
  	int		direction = 1;
  	int		ret;
  
  	fd = open(PX4IO_DEVICE_PATH, O_WRONLY);
  
  	if (fd < 0)
  		err(1, "failed to open device");
  
  	if (ioctl(fd, PWM_SERVO_GET_COUNT, (unsigned long)&servo_count))
  		err(1, "failed to get servo count");
  
  	/* tell IO that its ok to disable its safety with the switch */
  	ret = ioctl(fd, PWM_SERVO_SET_ARM_OK, 0);
  
  	if (ret != OK)
  		err(1, "PWM_SERVO_SET_ARM_OK");
  
  	if (ioctl(fd, PWM_SERVO_ARM, 0))
  		err(1, "failed to arm servos");
  
  	struct pollfd fds;
  	fds.fd = 0; /* stdin */
  	fds.events = POLLIN;
  
  	warnx("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;
  
  		ret = write(fd, servos, sizeof(servos));
  
  		if (ret != (int)sizeof(servos))
  			err(1, "error writing PWM servo data, wrote %u got %d", sizeof(servos), ret);
  
  		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))
  				err(1, "error reading PWM servo %d", i);
  
  			if (value != servos[i])
  				errx(1, "servo %d readback error, got %u expected %u", i, value, servos[i]);
  		}
  
  		/* 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') {
  				warnx("User abort\n");
  				exit(0);
  			}
  		}
  	}
  }
  
  void
  monitor(void)
  {
  	/* clear screen */
  	printf("\033[2J");
  
  	unsigned cancels = 2;
  
  	for (;;) {
  		pollfd fds[1];
  
  		fds[0].fd = 0;
  		fds[0].events = POLLIN;
  		poll(fds, 1, 2000);
  
  		if (fds[0].revents == POLLIN) {
  			int c;
  			read(0, &c, 1);
  
  			if (cancels-- == 0) {
  				printf("\033[2J\033[H"); /* move cursor home and clear screen */
  				exit(0);
  			}
  		}
  
  		if (g_dev != nullptr) {
  
  			printf("\033[2J\033[H"); /* move cursor home and clear screen */
  			(void)g_dev->print_status(false);
  			(void)g_dev->print_debug();
  			printf("\n\n\n[ Use 'px4io debug <N>' for more output. Hit <enter> three times to exit monitor mode ]\n");
  
  		} else {
  			errx(1, "driver not loaded, exiting");
  		}
  	}
  }
  
  void
  if_test(unsigned mode)
  {
  	device::Device *interface = get_interface();
  	int result;
  
  	if (interface) {
  		result = interface->ioctl(1, mode); /* XXX magic numbers */
  		delete interface;
  	} else {
  		errx(1, "interface not loaded, exiting");
  	}
  
  	errx(0, "test returned %d", result);
  }
  
  void
  lockdown(int argc, char *argv[])
  {
  	if (g_dev != nullptr) {
  
  			if (argc > 2 && !strcmp(argv[2], "disable")) {
  
  				warnx("WARNING: ACTUATORS WILL BE LIVE IN HIL! PROCEED?");
  				warnx("Press 'y' to enable, any other key to abort.");
  
  				/* check if user wants to abort */
  				char c;
  
  				struct pollfd fds;
  				int ret;
  				hrt_abstime start = hrt_absolute_time();
  				const unsigned long timeout = 5000000;
  
  				while (hrt_elapsed_time(&start) < timeout) {
  					fds.fd = 0; /* stdin */
  					fds.events = POLLIN;
  					ret = poll(&fds, 1, 0);
  
  					if (ret > 0) {
  
  						read(0, &c, 1);
  
  						if (c != 'y') {
  							exit(0);
  						} else if (c == 'y') {
  							break;
  						}
  					}
  
  					usleep(10000);
  				}
  
  				if (hrt_elapsed_time(&start) > timeout)
  					errx(1, "TIMEOUT! ABORTED WITHOUT CHANGES.");
  
  				(void)g_dev->ioctl(0, PWM_SERVO_SET_DISABLE_LOCKDOWN, 1);
  
  				warnx("WARNING: ACTUATORS ARE NOW LIVE IN HIL!");
  			} else {
  				(void)g_dev->ioctl(0, PWM_SERVO_SET_DISABLE_LOCKDOWN, 0);
  				warnx("ACTUATORS ARE NOW SAFE IN HIL.");
  			}
  
  		} else {
  			errx(1, "driver not loaded, exiting");
  		}
  	exit(0);
  }
  
  } /* namespace */
  
  int
  px4io_main(int argc, char *argv[])
  {
  	/* check for sufficient number of arguments */
  	if (argc < 2)
  		goto out;
  
  	if (!strcmp(argv[1], "start"))
  		start(argc - 1, argv + 1);
  
  	if (!strcmp(argv[1], "detect"))
  		detect(argc - 1, argv + 1);
  
  	if (!strcmp(argv[1], "checkcrc"))
  		checkcrc(argc - 1, argv + 1);
  
  	if (!strcmp(argv[1], "update")) {
  
  		if (g_dev != nullptr) {
  			printf("[px4io] loaded, detaching first\n");
  			/* stop the driver */
  			delete g_dev;
  			g_dev = nullptr;
  		}
  
  		PX4IO_Uploader *up;
  		const char *fn[4];
  
  		/* work out what we're uploading... */
  		if (argc > 2) {
  			fn[0] = argv[2];
  			fn[1] = nullptr;
  
  		} else {
  #if defined(CONFIG_ARCH_BOARD_PX4FMU_V1)
  			fn[0] = "/etc/extras/px4io-v1_default.bin";
  			fn[1] =	"/fs/microsd/px4io1.bin";
  			fn[2] =	"/fs/microsd/px4io.bin";
  			fn[3] =	nullptr;
  #elif defined(CONFIG_ARCH_BOARD_PX4FMU_V2)
  			fn[0] = "/etc/extras/px4io-v2_default.bin";
  			fn[1] =	"/fs/microsd/px4io2.bin";
  			fn[2] =	"/fs/microsd/px4io.bin";
  			fn[3] =	nullptr;
  #else
  #error "unknown board"
  #endif
  		}
  
  		up = new PX4IO_Uploader;
  		int ret = up->upload(&fn[0]);
  		delete up;
  
  		switch (ret) {
  		case OK:
  			break;
  
  		case -ENOENT:
  			errx(1, "PX4IO firmware file not found");
  
  		case -EEXIST:
  		case -EIO:
  			errx(1, "error updating PX4IO - check that bootloader mode is enabled");
  
  		case -EINVAL:
  			errx(1, "verify failed - retry the update");
  
  		case -ETIMEDOUT:
  			errx(1, "timed out waiting for bootloader - power-cycle and try again");
  
  		default:
  			errx(1, "unexpected error %d", ret);
  		}
  
  		return ret;
  	}
  
  	if (!strcmp(argv[1], "iftest")) {
  		if (g_dev != nullptr)
  			errx(1, "can't iftest when started");
  
  		if_test((argc > 2) ? strtol(argv[2], NULL, 0) : 0);
  	}
  
  	if (!strcmp(argv[1], "forceupdate")) {
  		/*
  		  force update of the IO firmware without requiring
  		  the user to hold the safety switch down
  		 */
  		if (argc <= 3) {
  			warnx("usage: px4io forceupdate MAGIC filename");
  			exit(1);
  		}
  		if (g_dev == nullptr) {
  			warnx("px4io is not started, still attempting upgrade");
  
  			/* allocate the interface */
  			device::Device *interface = get_interface();
  
  			/* create the driver - it will set g_dev */
  			(void)new PX4IO(interface);
  
  			if (g_dev == nullptr) {
  				delete interface;
  				errx(1, "driver alloc failed");
  			}
  		}
  
  		uint16_t arg = atol(argv[2]);
  		int ret = g_dev->ioctl(nullptr, PX4IO_REBOOT_BOOTLOADER, arg);
  		if (ret != OK) {
  			printf("reboot failed - %d\n", ret);
  			exit(1);
  		}
  
  		// tear down the px4io instance
  		delete g_dev;
  		g_dev = nullptr;
  
  		// upload the specified firmware
  		const char *fn[2];
  		fn[0] = argv[3];
  		fn[1] = nullptr;
  		PX4IO_Uploader *up = new PX4IO_Uploader;
  		up->upload(&fn[0]);
  		delete up;
  		exit(0);
  	}
  
  	/* commands below here require a started driver */
  
  	if (g_dev == nullptr)
  		errx(1, "not started");
  
  	if (!strcmp(argv[1], "limit")) {
  
  		if ((argc > 2)) {
  			g_dev->set_update_rate(atoi(argv[2]));
  
  		} else {
  			errx(1, "missing argument (50 - 500 Hz)");
  			return 1;
  		}
  
  		exit(0);
  	}
  
  	if (!strcmp(argv[1], "current")) {
  		if ((argc > 3)) {
  			g_dev->set_battery_current_scaling(atof(argv[2]), atof(argv[3]));
  
  		} else {
  			errx(1, "missing argument (apm_per_volt, amp_offset)");
  			return 1;
  		}
  
  		exit(0);
  	}
  
  
  
  	if (!strcmp(argv[1], "recovery")) {
  
  		/*
  		 * Enable in-air restart support.
  		 * We can cheat and call the driver directly, as it
  		 * doesn't reference filp in ioctl()
  		 */
  		g_dev->ioctl(NULL, PX4IO_INAIR_RESTART_ENABLE, 1);
  		exit(0);
  	}
  
  	if (!strcmp(argv[1], "stop")) {
  
  		/* stop the driver */
  		delete g_dev;
  		g_dev = nullptr;
  		exit(0);
  	}
  
  
  	if (!strcmp(argv[1], "status")) {
  
  		printf("[px4io] loaded\n");
  		g_dev->print_status(true);
  
  		exit(0);
  	}
  
  	if (!strcmp(argv[1], "debug")) {
  		if (argc <= 2) {
  			printf("usage: px4io debug LEVEL\n");
  			exit(1);
  		}
  
  		if (g_dev == nullptr) {
  			printf("px4io is not started\n");
  			exit(1);
  		}
  
  		uint8_t level = atoi(argv[2]);
  		/* we can cheat and call the driver directly, as it
  		 * doesn't reference filp in ioctl()
  		 */
  		int ret = g_dev->ioctl(nullptr, PX4IO_SET_DEBUG, level);
  
  		if (ret != 0) {
  			printf("SET_DEBUG failed - %d\n", ret);
  			exit(1);
  		}
  
  		printf("SET_DEBUG %u OK\n", (unsigned)level);
  		exit(0);
  	}
  
  	if (!strcmp(argv[1], "rx_dsm") ||
  	    !strcmp(argv[1], "rx_dsm_10bit") ||
  	    !strcmp(argv[1], "rx_dsm_11bit") ||
  	    !strcmp(argv[1], "rx_sbus") ||
  	    !strcmp(argv[1], "rx_ppm"))
  		errx(0, "receiver type is automatically detected, option '%s' is deprecated", argv[1]);
  
  	if (!strcmp(argv[1], "test"))
  		test();
  
  	if (!strcmp(argv[1], "monitor"))
  		monitor();
  
  	if (!strcmp(argv[1], "bind"))
  		bind(argc, argv);
  
  	if (!strcmp(argv[1], "lockdown"))
  		lockdown(argc, argv);
  
  	if (!strcmp(argv[1], "sbus1_out")) {
  		/* we can cheat and call the driver directly, as it
  		 * doesn't reference filp in ioctl()
  		 */
  		int ret = g_dev->ioctl(nullptr, SBUS_SET_PROTO_VERSION, 1);
  
  		if (ret != 0) {
  			errx(ret, "S.BUS v1 failed");
  		}
  
  		exit(0);
  	}
  
  	if (!strcmp(argv[1], "sbus2_out")) {
  		/* we can cheat and call the driver directly, as it
  		 * doesn't reference filp in ioctl()
  		 */
  		int ret = g_dev->ioctl(nullptr, SBUS_SET_PROTO_VERSION, 2);
  
  		if (ret != 0) {
  			errx(ret, "S.BUS v2 failed");
  		}
  
  		exit(0);
  	}
  
  	if (!strcmp(argv[1], "rssi_analog")) {
  		/* we can cheat and call the driver directly, as it
  		 * doesn't reference filp in ioctl()
  		 */
  		int ret = g_dev->ioctl(nullptr, RC_INPUT_ENABLE_RSSI_ANALOG, 1);
  
  		if (ret != 0) {
  			errx(ret, "RSSI analog failed");
  		}
  
  		exit(0);
  	}
  
  	if (!strcmp(argv[1], "rssi_pwm")) {
  		/* we can cheat and call the driver directly, as it
  		 * doesn't reference filp in ioctl()
  		 */
  		int ret = g_dev->ioctl(nullptr, RC_INPUT_ENABLE_RSSI_PWM, 1);
  
  		if (ret != 0) {
  			errx(ret, "RSSI PWM failed");
  		}
  
  		exit(0);
  	}
  
  out:
  	errx(1, "need a command, try 'start', 'stop', 'status', 'test', 'monitor', 'debug <level>',\n"
  	        "'recovery', 'limit <rate>', 'current', 'bind', 'checkcrc',\n"
  	        "'forceupdate', 'update', 'sbus1_out', 'sbus2_out', 'rssi_analog' or 'rssi_pwm'");
  }
  