MixingOutput: remove safety button check

The assumption is that the system can only ever get into armed state if
the safety button is already off.

src/lib/mixer_module/mixer_module.cpp

@@ -33,7 +33,6 @@
 
 #include "mixer_module.hpp"
 
-#include <lib/circuit_breaker/circuit_breaker.h>
 #include <uORB/PublicationQueued.hpp>
 #include <px4_log.h>
 
@@ -67,11 +66,6 @@ _control_latency_perf(perf_alloc(PC_ELAPSED, "control latency"))
 	_armed.force_failsafe = false;
 	_armed.in_esc_calibration_mode = false;
 
-	// If there is no safety button, disable it on init.
-#ifndef GPIO_BTN_SAFETY
-	_safety_off = true;
-#endif
-
 	px4_sem_init(&_lock, 0, 1);
 
 	// Enforce the existence of the test_motor topic, so we won't miss initial publications
@@ -108,12 +102,6 @@ void MixingOutput::updateParams()
 {
 	ModuleParams::updateParams();
 
-	bool safety_disabled = circuit_breaker_enabled_by_val(_param_cbrk_io_safety.get(), CBRK_IO_SAFETY_KEY);
-
-	if (safety_disabled) {
-		_safety_off = true;
-	}
-
 	// update mixer if we have one
 	if (_mixers) {
 		if (_param_mot_slew_max.get() <= FLT_EPSILON) {
@@ -296,7 +284,7 @@ bool MixingOutput::update()
 
 		/* 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);
+		_throttle_armed = (_armed.armed && !_armed.lockdown) || _armed.in_esc_calibration_mode;
 
 		if (_armed.armed) {
 			_motor_test.in_test_mode = false;
@@ -313,7 +301,6 @@ bool MixingOutput::update()
 				setAndPublishActuatorOutputs(num_motor_test, actuator_outputs);
 			}
 
-			checkSafetyButton();
 			handleCommands();
 			return true;
 		}
@@ -385,24 +372,11 @@ bool MixingOutput::update()
 		updateLatencyPerfCounter(actuator_outputs);
 	}
 
-	checkSafetyButton();
 	handleCommands();
 
 	return true;
 }
 
-void
-MixingOutput::checkSafetyButton()
-{
-	if (_safety_sub.updated()) {
-		safety_s safety;
-
-		if (_safety_sub.copy(&safety)) {
-			_safety_off = !safety.safety_switch_available || safety.safety_off;
-		}
-	}
-}
-
 void
 MixingOutput::setAndPublishActuatorOutputs(unsigned num_outputs, actuator_outputs_s &actuator_outputs)
 {

src/lib/mixer_module/mixer_module.hpp

@@ -50,7 +50,6 @@
 #include <uORB/topics/actuator_outputs.h>
 #include <uORB/topics/multirotor_motor_limits.h>
 #include <uORB/topics/parameter_update.h>
-#include <uORB/topics/safety.h>
 #include <uORB/topics/test_motor.h>
 
 
@@ -193,7 +192,6 @@ private:
 	unsigned motorTest();
 
 	void updateOutputSlewrate();
-	void checkSafetyButton();
 	void setAndPublishActuatorOutputs(unsigned num_outputs, actuator_outputs_s &actuator_outputs);
 	void publishMixerStatus(const actuator_outputs_s &actuator_outputs);
 	void updateLatencyPerfCounter(const actuator_outputs_s &actuator_outputs);
@@ -238,7 +236,6 @@ private:
 	output_limit_t _output_limit;
 
 	uORB::Subscription _armed_sub{ORB_ID(actuator_armed)};
-	uORB::Subscription _safety_sub{ORB_ID(safety)};
 	uORB::SubscriptionCallbackWorkItem _control_subs[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];
 
 	uORB::PublicationMulti<actuator_outputs_s> _outputs_pub{ORB_ID(actuator_outputs), ORB_PRIO_DEFAULT};
@@ -250,7 +247,6 @@ private:
 	hrt_abstime _time_last_mix{0};
 	unsigned _max_topic_update_interval_us{0}; ///< max _control_subs topic update interval (0=unlimited)
 
-	bool _safety_off{false}; ///< State of the safety button from the subscribed _safety_sub topic
 	bool _throttle_armed{false};
 	bool _ignore_lockdown{false}; ///< if true, ignore the _armed.lockdown flag (for HIL outputs)
 
@@ -279,8 +275,7 @@ private:
 		(ParamInt<px4::params::MC_AIRMODE>) _param_mc_airmode,   ///< multicopter air-mode
 		(ParamFloat<px4::params::MOT_SLEW_MAX>) _param_mot_slew_max,
 		(ParamFloat<px4::params::THR_MDL_FAC>) _param_thr_mdl_fac, ///< thrust to motor control signal modelling factor
-		(ParamInt<px4::params::MOT_ORDERING>) _param_mot_ordering,
-		(ParamInt<px4::params::CBRK_IO_SAFETY>) _param_cbrk_io_safety
+		(ParamInt<px4::params::MOT_ORDERING>) _param_mot_ordering
 
 	)
 };