PWM out: Collect settings for all outputs

There are settings that have to be the same for a split output across multiple instances, like for example the PWM mask and rate configurations. This change collects them for all outputs of the same underlying driver structure and applies the complete set.

src/drivers/pwm_out/PWMOut.cpp

@@ -531,12 +531,43 @@ void PWMOut::capture_callback(uint32_t chan_index,
 void PWMOut::update_pwm_out_state(bool on)
 {
 	if (on && !_pwm_initialized && _pwm_mask != 0) {
-		up_pwm_servo_init(_pwm_mask);
-		set_pwm_rate(_pwm_alt_rate_channels, _pwm_default_rate, _pwm_alt_rate);
+
+		// Collect all PWM masks from all instances
+		uint32_t pwm_mask_new = 0;
+		// Collect the PWM alt rate channels across all instances
+		uint32_t pwm_alt_rate_channels_new = 0;
+
+		// Collect the minimum default rate
+		unsigned default_rate_min = 0;
+		// Collect the maximum alternative rate (400 Hz or DSHOT outputs)
+		unsigned alt_rate_max = 0;
+
+		for (int i = 0; i < PWM_OUT_MAX_INSTANCES; i++) {
+			if (_objects[i].load()) {
+				pwm_mask_new |= _objects[i].load()->get_pwm_mask();
+				pwm_alt_rate_channels_new |= _objects[i].load()->get_alt_rate_channels();
+
+				if (_objects[i].load()->get_alt_rate() > alt_rate_max) {
+					alt_rate_max = _objects[i].load()->get_alt_rate();
+				}
+
+				if (_objects[i].load()->get_default_rate() < default_rate_min) {
+					default_rate_min = _objects[i].load()->get_default_rate();
+				}
+			}
+		}
+
+		// Initialize the PWM output state for all instances
+		// this is re-done once per instance, but harmless
+		up_pwm_servo_init(pwm_mask_new);
+
+		// Set rate is not affecting non-masked channels, so can be called
+		// individually
+		set_pwm_rate(pwm_alt_rate_channels_new, default_rate_min, alt_rate_max);
 		_pwm_initialized = true;
 	}
 
-	up_pwm_servo_arm(on); // TODO REVIEW for multi
+	up_pwm_servo_arm(on);
 }
 
 bool PWMOut::updateOutputs(bool stop_motors, uint16_t outputs[MAX_ACTUATORS],

src/drivers/pwm_out/PWMOut.hpp

@@ -159,6 +159,10 @@ public:
 
 	int		set_mode(Mode mode);
 	Mode		get_mode() { return _mode; }
+	uint32_t	get_pwm_mask() { return _pwm_mask; }
+	uint32_t	get_alt_rate_channels() { return _pwm_alt_rate_channels; }
+	unsigned	get_alt_rate() { return _pwm_alt_rate; }
+	unsigned	get_default_rate() { return _pwm_default_rate; }
 	void		request_mode(Mode new_mode);
 
 	static int	set_i2c_bus_clock(unsigned bus, unsigned clock_hz);