differential_pressure drivers: allow multiple instances of each driver

- the device path needs to be removed, as startup fails if it already
  exists
- sdp3x broadcasts a reset on startup, so do it only for the first I2C
  address

src/drivers/differential_pressure/ets/ets_airspeed.cpp

@@ -47,7 +47,6 @@
 
 /* I2C bus address */
 #define I2C_ADDRESS	0x75	/* 7-bit address. 8-bit address is 0xEA */
-#define ETS_PATH	"/dev/ets_airspeed"
 
 /* Register address */
 #define READ_CMD	0x07	/* Read the data */
@@ -64,8 +63,7 @@
 class ETSAirspeed : public Airspeed, public I2CSPIDriver<ETSAirspeed>
 {
 public:
-	ETSAirspeed(I2CSPIBusOption bus_option, const int bus, int bus_frequency, int address = I2C_ADDRESS,
-		    const char *path = ETS_PATH);
+	ETSAirspeed(I2CSPIBusOption bus_option, const int bus, int bus_frequency, int address = I2C_ADDRESS);
 
 	virtual ~ETSAirspeed() = default;
 
@@ -84,8 +82,8 @@ protected:
  */
 extern "C" __EXPORT int ets_airspeed_main(int argc, char *argv[]);
 
-ETSAirspeed::ETSAirspeed(I2CSPIBusOption bus_option, const int bus, int bus_frequency, int address, const char *path)
-	: Airspeed(bus, bus_frequency, address, CONVERSION_INTERVAL, path),
+ETSAirspeed::ETSAirspeed(I2CSPIBusOption bus_option, const int bus, int bus_frequency, int address)
+	: Airspeed(bus, bus_frequency, address, CONVERSION_INTERVAL),
 	  I2CSPIDriver(MODULE_NAME, px4::device_bus_to_wq(get_device_id()), bus_option, bus, address)
 {
 	_device_id.devid_s.devtype = DRV_DIFF_PRESS_DEVTYPE_MS4525;

src/drivers/differential_pressure/ms4525/ms4525_airspeed.cpp

@@ -65,7 +65,6 @@ enum MS_DEVICE_TYPE {
 /* I2C bus address is 1010001x */
 #define I2C_ADDRESS_MS4515DO	0x46
 #define I2C_ADDRESS_MS4525DO	0x28	/**< 7-bit address. Depends on the order code (this is for code "I") */
-#define PATH_MS4525		"/dev/ms4525"
 
 /* Register address */
 #define ADDR_READ_MR			0x00	/* write to this address to start conversion */
@@ -79,8 +78,7 @@ enum MS_DEVICE_TYPE {
 class MEASAirspeed : public Airspeed, public I2CSPIDriver<MEASAirspeed>
 {
 public:
-	MEASAirspeed(I2CSPIBusOption bus_option, const int bus, int bus_frequency, int address = I2C_ADDRESS_MS4525DO,
-		     const char *path = PATH_MS4525);
+	MEASAirspeed(I2CSPIBusOption bus_option, const int bus, int bus_frequency, int address = I2C_ADDRESS_MS4525DO);
 
 	virtual ~MEASAirspeed() = default;
 
@@ -111,8 +109,8 @@ protected:
  */
 extern "C" __EXPORT int ms4525_airspeed_main(int argc, char *argv[]);
 
-MEASAirspeed::MEASAirspeed(I2CSPIBusOption bus_option, const int bus, int bus_frequency, int address, const char *path)
-	: Airspeed(bus, bus_frequency, address, CONVERSION_INTERVAL, path),
+MEASAirspeed::MEASAirspeed(I2CSPIBusOption bus_option, const int bus, int bus_frequency, int address)
+	: Airspeed(bus, bus_frequency, address, CONVERSION_INTERVAL),
 	  I2CSPIDriver(MODULE_NAME, px4::device_bus_to_wq(get_device_id()), bus_option, bus, address)
 {
 	_device_id.devid_s.devtype = DRV_DIFF_PRESS_DEVTYPE_MS4525;

src/drivers/differential_pressure/ms5525/MS5525.hpp

@@ -43,8 +43,6 @@
 /* The MS5525DSO address is 111011Cx, where C is the complementary value of the pin CSB */
 static constexpr uint8_t I2C_ADDRESS_1_MS5525DSO = 0x76;
 
-static constexpr const char PATH_MS5525[] = "/dev/ms5525";
-
 /* Measurement rate is 100Hz */
 static constexpr unsigned MEAS_RATE = 100;
 static constexpr float MEAS_DRIVER_FILTER_FREQ = 1.2f;
@@ -53,9 +51,8 @@ static constexpr int64_t CONVERSION_INTERVAL = (1000000 / MEAS_RATE); /* microse
 class MS5525 : public Airspeed, public I2CSPIDriver<MS5525>
 {
 public:
-	MS5525(I2CSPIBusOption bus_option, const int bus, int bus_frequency, int address = I2C_ADDRESS_1_MS5525DSO,
-	       const char *path = PATH_MS5525) :
-		Airspeed(bus, bus_frequency, address, CONVERSION_INTERVAL, path),
+	MS5525(I2CSPIBusOption bus_option, const int bus, int bus_frequency, int address = I2C_ADDRESS_1_MS5525DSO) :
+		Airspeed(bus, bus_frequency, address, CONVERSION_INTERVAL),
 		I2CSPIDriver(MODULE_NAME, px4::device_bus_to_wq(get_device_id()), bus_option, bus, address)
 	{
 	}

src/drivers/differential_pressure/sdp3x/SDP3X.cpp

@@ -57,21 +57,25 @@ int SDP3X::write_command(uint16_t command)
 bool
 SDP3X::init_sdp3x()
 {
-	// step 1 - reset on broadcast
-	uint16_t prev_addr = get_device_address();
-	set_device_address(SDP3X_RESET_ADDR);
-	uint8_t reset_cmd = SDP3X_RESET_CMD;
-	int ret = transfer(&reset_cmd, 1, nullptr, 0);
-	set_device_address(prev_addr);
+	int ret;
 
-	if (ret != PX4_OK) {
-		perf_count(_comms_errors);
-		return false;
+	if (get_device_address() == I2C_ADDRESS_1_SDP3X) { // since we are broadcasting, only do it for the first device address
+		// step 1 - reset on broadcast
+		uint16_t prev_addr = get_device_address();
+		set_device_address(SDP3X_RESET_ADDR);
+		uint8_t reset_cmd = SDP3X_RESET_CMD;
+		ret = transfer(&reset_cmd, 1, nullptr, 0);
+		set_device_address(prev_addr);
+
+		if (ret != PX4_OK) {
+			perf_count(_comms_errors);
+			return false;
+		}
+
+		// wait until sensor is ready
+		px4_usleep(20000);
 	}
 
-	// wait until sensor is ready
-	px4_usleep(20000);
-
 	// step 2 - configure
 	ret = write_command(SDP3X_CONT_MEAS_AVG_MODE);
 

src/drivers/differential_pressure/sdp3x/SDP3X.hpp

@@ -61,8 +61,6 @@
 #define SDP3X_SCALE_PRESSURE_SDP32	240
 #define SDP3X_SCALE_PRESSURE_SDP33	20
 
-#define PATH_SDP3X "/dev/sdp3x"
-
 // Measurement rate is 20Hz
 #define SPD3X_MEAS_RATE 100
 #define SDP3X_MEAS_DRIVER_FILTER_FREQ 3.0f
@@ -71,9 +69,8 @@
 class SDP3X : public Airspeed, public I2CSPIDriver<SDP3X>
 {
 public:
-	SDP3X(I2CSPIBusOption bus_option, const int bus, int bus_frequency, int address = I2C_ADDRESS_1_SDP3X,
-	      const char *path = PATH_SDP3X) :
-		Airspeed(bus, bus_frequency, address, CONVERSION_INTERVAL, path),
+	SDP3X(I2CSPIBusOption bus_option, const int bus, int bus_frequency, int address = I2C_ADDRESS_1_SDP3X) :
+		Airspeed(bus, bus_frequency, address, CONVERSION_INTERVAL),
 		I2CSPIDriver(MODULE_NAME, px4::device_bus_to_wq(get_device_id()), bus_option, bus, address)
 	{
 	}

src/lib/drivers/airspeed/airspeed.cpp

@@ -56,8 +56,8 @@
 
 #include <drivers/airspeed/airspeed.h>
 
-Airspeed::Airspeed(int bus, int bus_frequency, int address, unsigned conversion_interval, const char *path) :
-	I2C("Airspeed", path, bus, address, bus_frequency),
+Airspeed::Airspeed(int bus, int bus_frequency, int address, unsigned conversion_interval) :
+	I2C("Airspeed", nullptr, bus, address, bus_frequency),
 	_sensor_ok(false),
 	_measure_interval(conversion_interval),
 	_collect_phase(false),

src/lib/drivers/airspeed/airspeed.h

@@ -46,7 +46,7 @@
 class __EXPORT Airspeed : public device::I2C
 {
 public:
-	Airspeed(int bus, int bus_frequency, int address, unsigned conversion_interval, const char *path);
+	Airspeed(int bus, int bus_frequency, int address, unsigned conversion_interval);
 	virtual ~Airspeed();
 
 	int	init() override;