px4io: added INAIR_RESTART enable/disable flags

the autopilot code needs to know that in-air restart may happen, so it
should be something that is enabled, rather than on by default.

apps/drivers/drv_pwm_output.h

@@ -109,6 +109,12 @@ ORB_DECLARE(output_pwm);
 /** set debug level for servo IO */
 #define PWM_SERVO_SET_DEBUG	_IOC(_PWM_SERVO_BASE, 4)
 
+/** enable in-air restart */
+#define PWM_SERVO_INAIR_RESTART_ENABLE	_IOC(_PWM_SERVO_BASE, 5)
+
+/** disable in-air restart */
+#define PWM_SERVO_INAIR_RESTART_DISABLE	_IOC(_PWM_SERVO_BASE, 6)
+
 /** set a single servo to a specific value */
 #define PWM_SERVO_SET(_servo)	_IOC(_PWM_SERVO_BASE, 0x20 + _servo)
 

apps/drivers/px4io/px4io.cpp

@@ -367,7 +367,12 @@ PX4IO::init()
 	if (ret != OK)
 		return ret;
 
-	if (reg & PX4IO_P_SETUP_ARMING_ARM_OK) {
+	/*
+	 * 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_ARM_OK)) {
 
 		/* WARNING: COMMANDER app/vehicle status must be initialized.
 		 * If this fails (or the app is not started), worst-case IO
@@ -450,6 +455,7 @@ PX4IO::init()
 		/* dis-arm IO before touching anything */
 		io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, 
 			PX4IO_P_SETUP_ARMING_ARM_OK |
+			PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK |
 			PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK |
 			PX4IO_P_SETUP_ARMING_VECTOR_FLIGHT_OK, 0);
 
@@ -1164,6 +1170,16 @@ PX4IO::ioctl(file *filep, int cmd, unsigned long arg)
 		ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, PX4IO_P_SETUP_ARMING_ARM_OK, 0);
 		break;
 
+	case PWM_SERVO_INAIR_RESTART_ENABLE:
+		/* set the 'in-air restart' bit */
+		ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, 0, PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK);
+		break;
+
+	case PWM_SERVO_INAIR_RESTART_DISABLE:
+		/* unset the 'in-air restart' bit */
+		ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING, PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK, 0);
+		break;
+
 	case PWM_SERVO_SET_UPDATE_RATE:
 		/* set the requested rate */
 		if ((arg >= 50) && (arg <= 400)) {

apps/px4io/protocol.h

@@ -142,6 +142,7 @@
 #define PX4IO_P_SETUP_ARMING_ARM_OK		(1 << 0) /* OK to arm */
 #define PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK	(1 << 2) /* OK to switch to manual override via override RC channel */
 #define PX4IO_P_SETUP_ARMING_VECTOR_FLIGHT_OK	(1 << 3) /* OK to perform position / vector control (= position lock) */
+#define PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK	(1 << 4) /* OK to try in-air restart */
 
 #define PX4IO_P_SETUP_PWM_RATES			2	/* bitmask, 0 = low rate, 1 = high rate */
 #define PX4IO_P_SETUP_PWM_LOWRATE		3	/* 'low' PWM frame output rate in Hz */

apps/px4io/registers.c

@@ -142,7 +142,8 @@ volatile uint16_t	r_page_setup[] =
 
 #define PX4IO_P_SETUP_FEATURES_VALID	(0)
 #define PX4IO_P_SETUP_ARMING_VALID	(PX4IO_P_SETUP_ARMING_ARM_OK | \
-					 PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK)
+					 PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK | \
+					 PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK)
 #define PX4IO_P_SETUP_RATES_VALID	((1 << IO_SERVO_COUNT) - 1)
 #define PX4IO_P_SETUP_RELAYS_VALID	((1 << PX4IO_RELAY_CHANNELS) - 1)