Added MS5805 altimeter.

drivers/sensors/Kconfig

@@ -31,6 +31,13 @@ config MB7040
 	---help---
 		Enable driver support for the MaxBotix MB7040 sonar.
 
+config MS5805
+	bool "MEAS MS5805 Altimeter support"
+	default n
+	select I2C
+	---help---
+		Enable driver support for the MEAS MS5805 altimeter.
+
 config MPL115A
 	bool "Freescale MPL115A Barometer Sensor support"
 	default n

drivers/sensors/Make.defs

@@ -73,6 +73,10 @@ ifeq ($(CONFIG_MB7040),y)
   CSRCS += mb7040.c
 endif
 
+ifeq ($(CONFIG_MS5805),y)
+  CSRCS += ms5805.c
+endif
+
 endif # CONFIG_I2C
 
 # These drivers depend on SPI support

drivers/sensors/ms5805.c

+/****************************************************************************
+ * drivers/sensors/ms5805.c
+ * Character driver for the MEAS MS5805 Altimeter
+ *
+ *   Copyright (C) 2015 Omni Hoverboards Inc. All rights reserved.
+ *   Author: Paul Alexander Patience <paul-a.patience@polymtl.ca>
+ *
+ * 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 NuttX 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <errno.h>
+#include <debug.h>
+#include <stdlib.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/fs/fs.h>
+#include <nuttx/arch.h>
+#include <nuttx/i2c.h>
+#include <nuttx/sensors/ms5805.h>
+
+#if defined(CONFIG_I2C) && defined(CONFIG_MS5805)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+/* I2C Address **************************************************************/
+
+#define MS5805_ADDR      0x76
+
+/* Register Definitions *****************************************************/
+/* Register Addresses */
+
+#define MS5805_RESET_REG 0x1e /* Reset Register */
+#define MS5805_PRESS_REG 0x40 /* Pressure Register */
+#define MS5805_TEMP_REG  0x50 /* Temperature Register */
+#define MS5805_ADC_REG   0x00 /* ADC Register */
+#define MS5805_PROM_REG  0xa0 /* PROM Register */
+
+/* PROM Definitions *********************************************************/
+
+#define MS5805_PROM_LEN  8
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+struct ms5805_dev_s
+{
+  FAR struct i2c_dev_s *i2c;   /* I2C interface */
+  int32_t               temp;  /* Uncompensated temperature (degrees Centigrade) */
+  int32_t               press; /* Uncompensated pressure (millibar) */
+  uint8_t               osr;   /* Oversampling ratio bits */
+  useconds_t            delay; /* Oversampling ratio delay */
+
+  /* Calibration coefficients */
+
+  uint16_t              c1;
+  uint16_t              c2;
+  uint16_t              c3;
+  uint16_t              c4;
+  uint16_t              c5;
+  uint16_t              c6;
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+/* CRC Calculation */
+
+static uint8_t ms5805_crc(FAR const uint8_t *src, size_t len);
+
+/* I2C Helpers */
+
+static int ms5805_readu16(FAR struct ms5805_dev_s *priv, uint8_t regaddr,
+                          FAR uint16_t *regval);
+static int ms5805_readadc(FAR struct ms5805_dev_s *priv, FAR uint32_t *adc);
+static int ms5805_setosr(FAR struct ms5805_dev_s *priv, uint16_t osr);
+static int ms5805_reset(FAR struct ms5805_dev_s *priv);
+static int ms5805_readprom(FAR struct ms5805_dev_s *priv);
+static int ms5805_convert(FAR struct ms5805_dev_s *priv, uint8_t regaddr,
+                          FAR uint32_t *regval);
+static int ms5805_measure(FAR struct ms5805_dev_s *priv);
+
+/* Character Driver Methods */
+
+static int     ms5805_open(FAR struct file *filep);
+static int     ms5805_close(FAR struct file *filep);
+static ssize_t ms5805_read(FAR struct file *filep, FAR char *buffer,
+                           size_t buflen);
+static ssize_t ms5805_write(FAR struct file *filep, FAR const char *buffer,
+                            size_t buflen);
+static int     ms5805_ioctl(FAR struct file *filep, int cmd,
+                            unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const struct file_operations g_fops =
+{
+  ms5805_open,
+  ms5805_close,
+  ms5805_read,
+  ms5805_write,
+  NULL,
+  ms5805_ioctl
+#ifndef CONFIG_DISABLE_POLL
+  , NULL
+#endif
+#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
+  , NULL
+#endif
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ms5805_crc
+ *
+ * Description:
+ *   Calculate the CRC.
+ *
+ ****************************************************************************/
+
+static uint8_t ms5805_crc(FAR const uint8_t *src, size_t len)
+{
+  uint16_t crc = 0;
+  size_t   i;
+  int      j;
+
+  for (i = 0; i < len; i++)
+    {
+      crc ^= src[i];
+
+      for (j = 0; j < 8; j++)
+        {
+          bool xor = (crc & 0x8000) != 0;
+
+          crc <<= 1;
+          if (xor)
+            {
+              crc ^= 0x3000;
+            }
+        }
+    }
+
+  return (uint8_t)(crc >> 12);
+}
+
+/****************************************************************************
+ * Name: ms5805_readu16
+ *
+ * Description:
+ *   Read from a 16-bit register.
+ *
+ ****************************************************************************/
+
+static int ms5805_readu16(FAR struct ms5805_dev_s *priv, uint8_t regaddr,
+                          FAR uint16_t *regval)
+{
+  uint8_t buffer[2];
+  int ret;
+
+  sndbg("addr: %02x\n", regaddr);
+
+  /* Write the register address */
+
+  I2C_SETADDRESS(priv->i2c, MS5805_ADDR, 7);
+  ret = I2C_WRITE(priv->i2c, &regaddr, sizeof(regaddr));
+  if (ret < 0)
+    {
+      sndbg("I2C_WRITE failed: %d\n", ret);
+      return ret;
+    }
+
+  /* Restart and read 16 bits from the register */
+
+  ret = I2C_READ(priv->i2c, buffer, sizeof(buffer));
+  if (ret < 0)
+    {
+      sndbg("I2C_READ failed: %d\n", ret);
+      return ret;
+    }
+
+  *regval = (uint16_t)buffer[0] << 8 | (uint16_t)buffer[1];
+  sndbg("value: %04x ret: %d\n", *regval, ret);
+  return ret;
+}
+
+/****************************************************************************
+ * Name: ms5805_readadc
+ *
+ * Description:
+ *   Read from the ADC register.
+ *
+ ****************************************************************************/
+
+static int ms5805_readadc(FAR struct ms5805_dev_s *priv, FAR uint32_t *adc)
+{
+  uint8_t regaddr;
+  uint8_t buffer[3];
+  int ret;
+
+  regaddr = MS5805_ADC_REG;
+  sndbg("addr: %02x\n", regaddr);
+
+  /* Write the register address */
+
+  I2C_SETADDRESS(priv->i2c, MS5805_ADDR, 7);
+  ret = I2C_WRITE(priv->i2c, &regaddr, sizeof(regaddr));
+  if (ret < 0)
+    {
+      sndbg("I2C_WRITE failed: %d\n", ret);
+      return ret;
+    }
+
+  /* Restart and read 24 bits from the register */
+
+  ret = I2C_READ(priv->i2c, buffer, sizeof(buffer));
+  if (ret < 0)
+    {
+      sndbg("I2C_READ failed: %d\n", ret);
+      return ret;
+    }
+
+  *adc = (uint32_t)buffer[0] << 16 |
+         (uint32_t)buffer[1] << 8 |
+         (uint32_t)buffer[2];
+  sndbg("adc: %06x ret: %d\n", *adc, ret);
+  return ret;
+}
+
+/****************************************************************************
+ * Name: ms5805_setosr
+ *
+ * Description:
+ *   Set the oversampling ratio.
+ *
+ ****************************************************************************/
+
+static int ms5805_setosr(FAR struct ms5805_dev_s *priv, uint16_t osr)
+{
+	int ret = OK;
+
+  sndbg("osr: %04x\n", osr);
+
+  switch (osr)
+    {
+      case 256:
+        priv->delay = 540;
+        break;
+
+      case 512:
+        priv->delay = 1060;
+        break;
+
+      case 1024:
+        priv->delay = 2080;
+        break;
+
+      case 2048:
+        priv->delay = 4130;
+        break;
+
+      case 4096:
+        priv->delay = 8220;
+        break;
+
+      case 8192:
+        priv->delay = 16440;
+        break;
+
+      default:
+        ret = -EINVAL;
+        break;
+    }
+
+  if (ret == OK)
+    {
+      priv->osr = (osr / 256 - 1) * 2;
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: ms5805_readprom
+ *
+ * Description:
+ *   Read from the PROM.
+ *
+ ****************************************************************************/
+
+static int ms5805_readprom(FAR struct ms5805_dev_s *priv)
+{
+  uint16_t prom[MS5805_PROM_LEN];
+  uint8_t  regaddr;
+  uint8_t  crc;
+  int      ret;
+  int      i;
+
+  regaddr = MS5805_PROM_REG;
+  for (i = 0; i < MS5805_PROM_LEN-1; i++)
+    {
+      ret = ms5805_readu16(priv, regaddr, prom+i);
+      if (ret < 0)
+        {
+          sndbg("ms5805_readu16 failed: %d\n", ret);
+          return ret;
+        }
+
+      regaddr += 2;
+    }
+
+  crc = (uint8_t)(prom[0] >> 12);
+
+  prom[0]                 = 0;
+  prom[MS5805_PROM_LEN-1] = 0;
+
+  if (crc != ms5805_crc((uint8_t *)prom, sizeof(prom)))
+    {
+      sndbg("crc mismatch\n");
+      return -ENODEV;
+    }
+
+  priv->c1 = prom[1];
+  priv->c2 = prom[2];
+  priv->c3 = prom[3];
+  priv->c4 = prom[4];
+  priv->c5 = prom[5];
+  priv->c6 = prom[6];
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: ms5805_reset
+ *
+ * Description:
+ *   Reset the device.
+ *
+ ****************************************************************************/
+
+static int ms5805_reset(FAR struct ms5805_dev_s *priv)
+{
+  uint8_t regaddr;
+	int ret;
+
+  regaddr = MS5805_RESET_REG;
+  sndbg("addr: %02x\n", regaddr);
+
+  /* Write the register address */
+
+  I2C_SETADDRESS(priv->i2c, MS5805_ADDR, 7);
+  ret = I2C_WRITE(priv->i2c, &regaddr, sizeof(regaddr));
+  if (ret < 0)
+    {
+      sndbg("I2C_WRITE failed: %d\n", ret);
+      return ret;
+    }
+
+  /* Check the CRC and read the calibration coefficients */
+
+  ret = ms5805_readprom(priv);
+  if (ret < 0)
+    {
+      sndbg("ms5805_readprom failed: %d\n", ret);
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: ms5805_convert
+ *
+ * Description:
+ *   Measure the uncompensated temperature or the uncompensated pressure.
+ *
+ ****************************************************************************/
+
+static int ms5805_convert(FAR struct ms5805_dev_s *priv, uint8_t regaddr,
+                          FAR uint32_t *regval)
+{
+	int ret;
+
+  regaddr |= priv->osr;
+  sndbg("addr: %02x\n", regaddr);
+
+  /* Write the register address */
+
+  I2C_SETADDRESS(priv->i2c, MS5805_ADDR, 7);
+  ret = I2C_WRITE(priv->i2c, &regaddr, sizeof(regaddr));
+  if (ret < 0)
+    {
+      sndbg("I2C_WRITE failed: %d\n", ret);
+    }
+
+  /* Wait for the conversion to end */
+
+  up_udelay(priv->delay);
+
+  /* Read the value from the ADC */
+
+  ret = ms5805_readadc(priv, regval);
+  if (ret < 0)
+    {
+      sndbg("ms5805_readadc failed: %d\n", ret);
+      return ret;
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: ms5805_measure
+ *
+ * Description:
+ *   Measure the compensated temperature and the compensated pressure.
+ *
+ ****************************************************************************/
+
+static int ms5805_measure(FAR struct ms5805_dev_s *priv)
+{
+  uint32_t rawpress;
+  uint32_t rawtemp;
+  int32_t diff;
+  int32_t temp;
+  int64_t off;
+  int64_t sens;
+  int32_t press;
+	int ret;
+
+  ret = ms5805_convert(priv, MS5805_PRESS_REG, &rawpress);
+  if (ret < 0)
+    {
+      sndbg("ms5805_convert failed: %d\n", ret);
+      return ret;
+    }
+
+  ret = ms5805_convert(priv, MS5805_TEMP_REG, &rawtemp);
+  if (ret < 0)
+    {
+      sndbg("ms5805_convert failed: %d\n", ret);
+      return ret;
+    }
+
+  diff = (int32_t)rawtemp - (int32_t)priv->c5 / ((int32_t)1 << 8);
+  temp = (int32_t)((int64_t)20 +
+                   (int64_t)diff * (int64_t)priv->c6 / ((int64_t)1 << 23));
+
+  off  = (int64_t)priv->c2 * ((int64_t)1 << 17) +
+         (int64_t)priv->c4 * (int64_t)diff / ((int64_t)1 << 8);
+  sens = (int64_t)priv->c1 * ((int64_t)1 << 16) +
+         (int64_t)priv->c3 * (int64_t)diff / ((int64_t)1 << 7);
+
+  if (temp < 2000)
+    {
+      int32_t ti;
+      int64_t offi;
+      int64_t sensi;
+
+      ti    = (int32_t)((int64_t)11 * (int64_t)diff *
+                        (int64_t)diff / ((int64_t)1 << 35));
+      offi  = (int64_t)31 * ((int64_t)temp - (int64_t)2000) *
+              ((int64_t)temp - (int64_t)2000) / ((int64_t)1 << 3);
+      sensi = (int64_t)63 * ((int64_t)temp - (int64_t)2000) *
+              ((int64_t)temp - (int64_t)2000) / ((int64_t)1 << 5);
+
+      temp -= ti;
+      off  -= offi;
+      sens -= sensi;
+    }
+
+  press = (int32_t)(((int64_t)rawpress * sens / ((int64_t)1 << 21) - off) /
+                    ((int64_t)1 << 15));
+
+  priv->temp = temp / (int32_t)100;
+  priv->press = press / (int32_t)100;
+  return ret;
+}
+
+/****************************************************************************
+ * Name: ms5805_open
+ *
+ * Description:
+ *   This method is called when the device is opened.
+ *
+ ****************************************************************************/
+
+static int ms5805_open(FAR struct file *filep)
+{
+  return OK;
+}
+
+/****************************************************************************
+ * Name: ms5805_close
+ *
+ * Description:
+ *   This method is called when the device is closed.
+ *
+ ****************************************************************************/
+
+static int ms5805_close(FAR struct file *filep)
+{
+  return OK;
+}
+
+/****************************************************************************
+ * Name: ms5805_read
+ *
+ * Description:
+ *   A dummy read method.
+ *
+ ****************************************************************************/
+
+static ssize_t ms5805_read(FAR struct file *filep, FAR char *buffer,
+                           size_t buflen)
+{
+  return 0;
+}
+
+/****************************************************************************
+ * Name: ms5805_write
+ *
+ * Description:
+ *   A dummy write method.
+ *
+ ****************************************************************************/
+
+static ssize_t ms5805_write(FAR struct file *filep, FAR const char *buffer,
+                            size_t buflen)
+{
+  return -ENOSYS;
+}
+
+/****************************************************************************
+ * Name: ms5805_ioctl
+ *
+ * Description:
+ *   The standard ioctl method.
+ *
+ ****************************************************************************/
+
+static int ms5805_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
+{
+  FAR struct inode        *inode = filep->f_inode;
+  FAR struct ms5805_dev_s *priv  = inode->i_private;
+  int                      ret   = OK;
+
+  /* Handle ioctl commands */
+
+  switch (cmd)
+    {
+      /* Measure the temperature and the pressure. Arg: None. */
+
+      case SNIOC_MEASURE:
+        DEBUGASSERT(arg == 0);
+        ret = ms5805_measure(priv);
+        break;
+
+      /* Return the temperature last measured. Arg: int32_t* pointer. */
+
+      case SNIOC_TEMPERATURE:
+        {
+          FAR int32_t *ptr = (FAR int32_t *)((uintptr_t)arg);
+          DEBUGASSERT(ptr != NULL);
+          *ptr = priv->temp;
+          sndbg("temp: %08x\n", *ptr);
+        }
+        break;
+
+      /* Return the pressure last measured. Arg: int32_t* pointer. */
+
+      case SNIOC_PRESSURE:
+        {
+          FAR int32_t *ptr = (FAR int32_t *)((uintptr_t)arg);
+          DEBUGASSERT(ptr != NULL);
+          *ptr = priv->press;
+          sndbg("press: %08x\n", *ptr);
+        }
+        break;
+
+      /* Reset the device. Arg: None. */
+
+      case SNIOC_RESET:
+        DEBUGASSERT(arg == 0);
+        ret = ms5805_reset(priv);
+        break;
+
+      /* Change the oversampling ratio. Arg: uint16_t value. */
+
+      case SNIOC_OVERSAMPLING:
+        ret = ms5805_setosr(priv, (uint16_t)arg);
+        sndbg("osr: %04x ret: %d\n", *(uint16_t *)arg, ret);
+        break;
+
+      /* Unrecognized commands */
+
+      default:
+        sndbg("Unrecognized cmd: %d arg: %ld\n", cmd, arg);
+        ret = -ENOTTY;
+        break;
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ms5805_register
+ *
+ * Description:
+ *   Register the MS5805 character device as 'devpath'.
+ *
+ * Input Parameters:
+ *   devpath - The full path to the driver to register, e.g., "/dev/press0".
+ *   i2c     - An I2C driver instance.
+ *   osr     - The oversampling ratio.
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int ms5805_register(FAR const char *devpath, FAR struct i2c_dev_s *i2c,
+                    uint16_t osr)
+{
+  FAR struct ms5805_dev_s *priv;
+  int ret;
+
+  /* Sanity check */
+
+  DEBUGASSERT(i2c != NULL);
+
+  /* Initialize the device's structure */
+
+  priv = (FAR struct ms5805_dev_s *)kmm_malloc(sizeof(*priv));
+  if (priv == NULL)
+    {
+      sndbg("Failed to allocate instance\n");
+      return -ENOMEM;
+    }
+
+  priv->i2c   = i2c;
+  priv->temp  = 0;
+  priv->press = 0;
+
+  ret = ms5805_setosr(priv, osr);
+  if (ret < 0)
+    {
+      sndbg("ms5805_setosr failed: %d\n", ret);
+      goto err;
+    }
+
+  ret = ms5805_reset(priv);
+  if (ret < 0)
+    {
+      sndbg("ms5805_reset failed: %d\n", ret);
+      goto err;
+    }
+
+  /* Register the character driver */
+
+  ret = register_driver(devpath, &g_fops, 0666, priv);
+  if (ret < 0)
+    {
+      sndbg("Failed to register driver: %d\n", ret);
+      goto err;
+    }
+
+  return ret;
+
+err:
+  kmm_free(priv);
+  return ret;
+}
+
+#endif /* CONFIG_I2C && CONFIG_MS5805 */

include/nuttx/sensors/ms5805.h

+/****************************************************************************
+ * include/nuttx/sensors/ms5805.h
+ *
+ *   Copyright (C) 2015 Omni Hoverboards Inc. All rights reserved.
+ *   Author: Paul Alexander Patience <paul-a.patience@polymtl.ca>
+ *
+ * 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 NuttX 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.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_SENSORS_MS5805
+#define __INCLUDE_NUTTX_SENSORS_MS5805
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/fs/ioctl.h>
+
+#if defined(CONFIG_I2C) && defined(CONFIG_MS5805)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+/* Configuration ************************************************************
+ * Prerequisites:
+ *
+ * CONFIG_I2C
+ *   Enables support for I2C drivers
+ * CONFIG_MS5805
+ *   Enables support for the MS5805 driver
+ */
+
+/* IOCTL Commands ***********************************************************/
+
+#define SNIOC_MEASURE      _SNIOC(0x0001) /* Arg: None */
+#define SNIOC_TEMPERATURE  _SNIOC(0x0002) /* Arg: int32_t* pointer */
+#define SNIOC_PRESSURE     _SNIOC(0x0003) /* Arg: int32_t* pointer */
+#define SNIOC_RESET        _SNIOC(0x0004) /* Arg: None */
+#define SNIOC_OVERSAMPLING _SNIOC(0x0005) /* Arg: uint16_t value */
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+struct i2c_dev_s;
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: ms5805_register
+ *
+ * Description:
+ *   Register the MS5805 character device as 'devpath'.
+ *
+ * Input Parameters:
+ *   devpath - The full path to the driver to register, e.g., "/dev/press0".
+ *   i2c     - An I2C driver instance.
+ *   osr     - The oversampling ratio.
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int ms5805_register(FAR const char *devpath, FAR struct i2c_dev_s *i2c,
+                    uint16_t osr);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* CONFIG_I2C && CONFIG_MS5805 */
+#endif /* __INCLUDE_NUTTX_SENSORS_MS5805 */