Refactor MS5611 driver to use interface nubs for the I2C and SPI versions of the chip. This reduces the amount of duplicated code.

src/drivers/ms5611/ms5611_spi.cpp

@@ -0,0 +1,228 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2013 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 ms5611_spi.cpp
+  *
+  * SPI interface for MS5611
+  */
+
+
+/* SPI protocol address bits */
+#define DIR_READ			(1<<7)
+#define DIR_WRITE			(0<<7)
+#define ADDR_INCREMENT			(1<<6)
+
+device::Device *MS5611_spi_interface();
+
+class MS5611_SPI : device::SPI
+{
+public:
+	MS5611_SPI(int bus, spi_dev_e device);
+	virtual ~MS5611_SPI();
+
+	virtual int	init();
+	virtual int	read(unsigned offset, void *data, unsigned count);
+	virtual int	ioctl(unsigned operation, unsigned &arg);
+
+protected:
+	virtual int	probe();
+
+private:
+	ms5611::prom_u	*_prom
+
+	int		_probe_address(uint8_t address);
+
+	/**
+	 * Send a reset command to the MS5611.
+	 *
+	 * This is required after any bus reset.
+	 */
+	int		_reset();
+
+	/**
+	 * Send a measure command to the MS5611.
+	 *
+	 * @param addr		Which address to use for the measure operation.
+	 */
+	int		_measure(unsigned addr);
+
+	/**
+	 * Read the MS5611 PROM
+	 *
+	 * @return		OK if the PROM reads successfully.
+	 */
+	int		_read_prom();
+
+	/**
+	 * Read a 16-bit register value.
+	 *
+	 * @param reg		The register to read.
+	 */
+	uint16_t	_reg16(unsigned reg);
+};
+
+device::Device *
+MS5611_spi_interface()
+{
+#ifdef PX4_SPIDEV_BARO
+	return new MS5611_SPI(1 /* XXX MAGIC NUMBER */, (spi_dev_e)PX4_SPIDEV_BARO);
+#endif
+	return nullptr;
+}
+
+int
+MS5611_SPI::init()
+{
+	int ret;
+
+	ret = SPI::init();
+	if (ret != OK)
+		goto out;
+
+	/* send reset command */
+	ret = _reset();
+	if (ret != OK)
+		goto out;
+
+	/* read PROM */
+	ret = _read_prom();
+	if (ret != OK)
+		goto out;
+
+out:
+	return ret;
+}
+
+int
+MS5611_SPI::read(unsigned offset, void *data, unsigned count)
+{
+	union _cvt {
+		uint8_t	b[4];
+		uint32_t w;
+	} *cvt = (_cvt *)data;
+	uint8_t buf[4];
+
+	/* read the most recent measurement */
+	buf[0] = 0 | DIR_WRITE;
+	int ret = transfer(&buf[0], &buf[0], sizeof(buf));
+
+	if (ret == OK) {
+		/* fetch the raw value */
+		cvt->b[0] = data[3];
+		cvt->b[1] = data[2];
+		cvt->b[2] = data[1];
+		cvt->b[3] = 0;
+
+		ret = count;
+	}
+
+	return ret;
+}
+
+int
+MS5611_SPI::ioctl(unsigned operation, unsigned &arg)
+{
+	int ret;
+
+	switch (operation) {
+	case IOCTL_SET_PROMBUFFER:
+		_prom = reinterpret_cast<ms5611_prom_u *>(arg);
+		return OK;
+
+	case IOCTL_RESET:
+		ret = _reset();
+		break;
+
+	case IOCTL_MEASURE:
+		ret = _measure(arg);
+		break;
+
+	default:
+		ret = EINVAL;
+	}
+
+	if (ret != OK) {
+		errno = ret;
+		return -1;
+	}
+	return 0;
+}
+
+int
+MS5611_SPI::_reset()
+{
+	uint8_t cmd = ADDR_RESET_CMD | DIR_WRITE;
+
+	return  transfer(&cmd, nullptr, 1);
+}
+
+int
+MS5611_SPI::_measure(unsigned addr)
+{
+	uint8_t cmd = addr | DIR_WRITE;
+
+	return transfer(&cmd, nullptr, 1);
+}
+
+
+int
+MS5611_SPI::_read_prom()
+{
+	/*
+	 * Wait for PROM contents to be in the device (2.8 ms) in the case we are
+	 * called immediately after reset.
+	 */
+	usleep(3000);
+
+	/* read and convert PROM words */
+	for (int i = 0; i < 8; i++) {
+		uint8_t cmd = (ADDR_PROM_SETUP + (i * 2));
+		_prom.c[i] = _reg16(cmd);
+	}
+
+	/* calculate CRC and return success/failure accordingly */
+	return ms5611::crc4(&_prom.c[0]) ? OK : -EIO;
+}
+
+uint16_t
+MS5611_SPI::_reg16(unsigned reg)
+{
+	uint8_t cmd[3];
+
+	cmd[0] = reg | DIR_READ;
+
+	transfer(cmd, cmd, sizeof(cmd));
+
+	return (uint16_t)(cmd[1] << 8) | cmd[2];
+}