623 lines
17 KiB
C
623 lines
17 KiB
C
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/****************************************************************************
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* drivers/sensors/bmp180.c
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* Character driver for the Freescale BMP1801 Barometer Sensor
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*
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* Copyright (C) 2015 Gregory Nutt. All rights reserved.
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* Copyright (C) 2015 Alan Carvalho de Assis
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* Author: Alan Carvalho de Assis <acassis@gmail.com>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <stdlib.h>
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#include <fixedmath.h>
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#include <errno.h>
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#include <debug.h>
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#include <nuttx/kmalloc.h>
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#include <nuttx/fs/fs.h>
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#include <nuttx/i2c.h>
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#include <nuttx/sensors/bmp180.h>
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#if defined(CONFIG_I2C) && defined(CONFIG_BMP180)
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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#define BMP180_ADDR 0x77
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#define BMP180_FREQ 100000
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#define DEVID 0x55
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#define BMP180_AC1_MSB 0xaa
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#define BMP180_AC1_LSB 0xab
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#define BMP180_AC2_MSB 0xac
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#define BMP180_AC2_LSB 0xad
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#define BMP180_AC3_MSB 0xae
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#define BMP180_AC3_LSB 0xaf
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#define BMP180_AC4_MSB 0xb0
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#define BMP180_AC4_LSB 0xb1
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#define BMP180_AC5_MSB 0xb2
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#define BMP180_AC5_LSB 0xb3
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#define BMP180_AC6_MSB 0xb4
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#define BMP180_AC6_LSB 0xb5
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#define BMP180_B1_MSB 0xb6
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#define BMP180_B1_LSB 0xb7
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#define BMP180_B2_MSB 0xb8
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#define BMP180_B2_LSB 0xb9
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#define BMP180_MB_MSB 0xba
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#define BMP180_MB_LSB 0xbb
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#define BMP180_MC_MSB 0xbc
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#define BMP180_MC_LSB 0xbd
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#define BMP180_MD_MSB 0xbe
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#define BMP180_MD_LSB 0xbf
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#define BMP180_DEVID 0xd0
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#define BMP180_SOFT_RESET 0xe0
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#define BMP180_CTRL_MEAS 0xf4
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#define BMP180_ADC_OUT_MSB 0xf6
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#define BMP180_ADC_OUT_LSB 0xf7
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#define BMP180_ADC_OUT_XLSB 0xf8
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#define BMP180_READ_TEMP 0x2e
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#define BMP180_READ_PRESS 0x34
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#define BMP180_NOOVERSAMPLE 0x00
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#define BMP180_OVERSAMPLE2X 0x70
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#define BMP180_OVERSAMPLE4X 0xb0
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#define BMP180_OVERSAMPLE8X 0xc0
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/* Current Oversampling */
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#define CURRENT_OSS (BMP180_OVERSAMPLE8X)
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/****************************************************************************
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* Private Type Definitions
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****************************************************************************/
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struct bmp180_dev_s
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{
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FAR struct i2c_dev_s *i2c; /* I2C interface */
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uint8_t addr; /* BMP180 I2C address */
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int freq; /* BMP180 Frequency <= 3.4MHz */
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int16_t bmp180_cal_ac1; /* Calibration coefficients */
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int16_t bmp180_cal_ac2;
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int16_t bmp180_cal_ac3;
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uint16_t bmp180_cal_ac4;
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uint16_t bmp180_cal_ac5;
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uint16_t bmp180_cal_ac6;
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int16_t bmp180_cal_b1;
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int16_t bmp180_cal_b2;
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int16_t bmp180_cal_mb;
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int16_t bmp180_cal_mc;
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int16_t bmp180_cal_md;
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int32_t bmp180_utemp; /* Uncompensated temperature read from BMP180 */
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int32_t bmp180_upress; /* Uncompensated pressure read from BMP180 */
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};
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/****************************************************************************
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* Private Function Prototypes
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****************************************************************************/
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static uint8_t bmp180_getreg8(FAR struct bmp180_dev_s *priv, uint8_t regaddr);
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static uint16_t bmp180_getreg16(FAR struct bmp180_dev_s *priv, uint8_t regaddr);
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static void bmp180_putreg8(FAR struct bmp180_dev_s *priv, uint8_t regaddr,
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uint8_t regval);
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static void bmp180_updatecaldata(FAR struct bmp180_dev_s *priv);
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static void bmp180_read_press_temp(FAR struct bmp180_dev_s *priv);
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static int bmp180_getpressure(FAR struct bmp180_dev_s *priv);
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/* Character driver methods */
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static int bmp180_open(FAR struct file *filep);
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static int bmp180_close(FAR struct file *filep);
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static ssize_t bmp180_read(FAR struct file *filep, FAR char *buffer,
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size_t buflen);
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static ssize_t bmp180_write(FAR struct file *filep, FAR const char *buffer,
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size_t buflen);
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/****************************************************************************
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* Private Data
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****************************************************************************/
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static const struct file_operations g_bmp180fops =
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{
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bmp180_open, /* open */
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bmp180_close, /* close */
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bmp180_read, /* read */
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bmp180_write, /* write */
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0, /* seek */
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0, /* ioctl */
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#ifndef CONFIG_DISABLE_POLL
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0, /* poll */
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#endif
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0 /* unlink */
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};
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: bmp180_getreg8
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*
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* Description:
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* Read from an 8-bit BMP180 register
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*
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****************************************************************************/
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static uint8_t bmp180_getreg8(FAR struct bmp180_dev_s *priv, uint8_t regaddr)
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{
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int ret;
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uint8_t regval = 0;
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/* Restart the register */
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ret = I2C_WRITE(priv->i2c, ®addr, 1);
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if (ret < 0)
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{
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sndbg("I2C_WRITE failed: %d\n", ret);
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return ret;
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}
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/* Restart the register */
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ret = I2C_READ(priv->i2c, ®val, 1);
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if (ret < 0)
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{
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sndbg("I2C_READ failed: %d\n", ret);
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return ret;
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}
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return regval;
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}
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/****************************************************************************
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* Name: bmp180_getreg16
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*
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* Description:
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* Read two 8-bit from a BMP180 register
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*
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****************************************************************************/
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static uint16_t bmp180_getreg16(FAR struct bmp180_dev_s *priv, uint8_t regaddr)
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{
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int ret;
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uint16_t msb, lsb;
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uint16_t regval = 0;
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/* Register to read */
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ret = I2C_WRITE(priv->i2c, ®addr, 1);
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if (ret < 0)
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{
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sndbg("I2C_WRITE failed: %d\n", ret);
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return ret;
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}
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/* Read register */
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ret = I2C_READ(priv->i2c, (uint8_t *)®val, 2);
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if (ret < 0)
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{
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sndbg("I2C_READ failed: %d\n", ret);
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return ret;
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}
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/* MSB and LSB are inverted */
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msb = (regval & 0xFF);
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lsb = (regval & 0xFF00) >> 8;
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regval = (msb << 8) | lsb;
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return regval;
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}
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/****************************************************************************
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* Name: bmp180_putreg8
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*
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* Description:
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* Write to an 8-bit BMP180 register
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*
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****************************************************************************/
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static void bmp180_putreg8(FAR struct bmp180_dev_s *priv, uint8_t regaddr,
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uint8_t regval)
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{
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int ret;
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uint8_t data[2];
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data[0] = regaddr;
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data[1] = regval;
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/* Restart the register */
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ret = I2C_WRITE(priv->i2c, (uint8_t *) &data, 2);
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if (ret < 0)
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{
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sndbg("I2C_WRITE failed: %d\n", ret);
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return;
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}
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return;
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}
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/****************************************************************************
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* Name: bmp180_checkid
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*
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* Description:
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* Read and verify the BMP180 chip ID
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*
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****************************************************************************/
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static int bmp180_checkid(FAR struct bmp180_dev_s *priv)
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{
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uint8_t devid = 0;
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/* Read device ID */
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devid = bmp180_getreg8(priv, BMP180_DEVID);
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snvdbg("devid: 0x%02x\n", devid);
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if (devid != (uint16_t) DEVID)
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{
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/* ID is not Correct */
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sndbg("Wrong Device ID!\n");
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return -ENODEV;
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}
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return OK;
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}
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/****************************************************************************
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* Name: bmp180_updatecaldata
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*
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* Description:
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* Update Calibration Coefficient Data
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*
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****************************************************************************/
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static void bmp180_updatecaldata(FAR struct bmp180_dev_s *priv)
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{
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/* AC1 */
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priv->bmp180_cal_ac1 = (int16_t) bmp180_getreg16(priv, BMP180_AC1_MSB);
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/* AC2 */
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priv->bmp180_cal_ac2 = (int16_t) bmp180_getreg16(priv, BMP180_AC2_MSB);
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/* AC3 */
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priv->bmp180_cal_ac3 = (int16_t) bmp180_getreg16(priv, BMP180_AC3_MSB);
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/* AC4 */
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priv->bmp180_cal_ac4 = bmp180_getreg16(priv, BMP180_AC4_MSB);
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/* AC5 */
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priv->bmp180_cal_ac5 = bmp180_getreg16(priv, BMP180_AC5_MSB);
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/* AC6 */
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priv->bmp180_cal_ac6 = bmp180_getreg16(priv, BMP180_AC6_MSB);
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/* B1 */
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priv->bmp180_cal_b1 = (int16_t) bmp180_getreg16(priv, BMP180_B1_MSB);
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/* B2 */
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priv->bmp180_cal_b2 = (int16_t) bmp180_getreg16(priv, BMP180_B2_MSB);
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/* MB */
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priv->bmp180_cal_mb = (int16_t) bmp180_getreg16(priv, BMP180_MB_MSB);
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/* MC */
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priv->bmp180_cal_mc = (int16_t) bmp180_getreg16(priv, BMP180_MC_MSB);
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/* MD */
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priv->bmp180_cal_md = (int16_t) bmp180_getreg16(priv, BMP180_MD_MSB);
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}
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/****************************************************************************
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* Name: bmp180_read_press_temp
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*
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* Description:
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* Read raw pressure and temperature from BMP180 and store it in the
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* bmp180_dev_s structure.
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*
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****************************************************************************/
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static void bmp180_read_press_temp(FAR struct bmp180_dev_s *priv)
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{
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uint8_t oss = CURRENT_OSS;
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/* Issue a read temperature command */
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bmp180_putreg8(priv, BMP180_CTRL_MEAS, BMP180_READ_TEMP);
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/* Wait 5ms */
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usleep(5000);
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/* Read temperature */
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priv->bmp180_utemp = bmp180_getreg16(priv, BMP180_ADC_OUT_MSB);
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/* Issue a read pressure command */
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bmp180_putreg8(priv, BMP180_CTRL_MEAS, (BMP180_READ_PRESS | oss));
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/* Delay 25.5ms (to OverSampling 8X) */
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usleep(25500);
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/* Read pressure */
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priv->bmp180_upress = bmp180_getreg16(priv, BMP180_ADC_OUT_MSB) << 8;
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priv->bmp180_upress |= bmp180_getreg8(priv, BMP180_ADC_OUT_XLSB);
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priv->bmp180_upress = priv->bmp180_upress >> (8 - (oss >> 6));
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snvdbg("Uncompensated temperature = %d\n", priv->bmp180_utemp);
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snvdbg("Uncompensated pressure = %d\n", priv->bmp180_upress);
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}
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/****************************************************************************
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* Name: bmp180_getpressure
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*
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* Description:
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* Calculate the Barometric Pressure using the temperature compensated
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* See Freescale AN3785 and BMP1801 data sheet for details
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*
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****************************************************************************/
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static int bmp180_getpressure(FAR struct bmp180_dev_s *priv)
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{
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int32_t x1;
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int32_t x2;
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int32_t x3;
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int32_t b3;
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int32_t b5;
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int32_t b6;
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int32_t press;
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int32_t temp;
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uint32_t b4;
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uint32_t b7;
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uint8_t oss = (CURRENT_OSS >> 6);
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/* Check if coefficient data were read correctly */
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if ((priv->bmp180_cal_ac1 == 0) || (priv->bmp180_cal_ac2 == 0) ||
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(priv->bmp180_cal_ac3 == 0) || (priv->bmp180_cal_ac4 == 0) ||
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(priv->bmp180_cal_ac5 == 0) || (priv->bmp180_cal_ac6 == 0) ||
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(priv->bmp180_cal_b1 == 0) || (priv->bmp180_cal_b2 == 0) ||
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(priv->bmp180_cal_mb == 0) || (priv->bmp180_cal_mc == 0) ||
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(priv->bmp180_cal_md == 0))
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{
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bmp180_updatecaldata(priv);
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}
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/* Read temperature and pressure */
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bmp180_read_press_temp(priv);
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/* Calculate true temperature */
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x1 = ((priv->bmp180_utemp - priv->bmp180_cal_ac6) * priv->bmp180_cal_ac5) >> 15;
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x2 = (priv->bmp180_cal_mc << 11) / (x1 + priv->bmp180_cal_md);
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b5 = x1 + x2;
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temp = (b5 + 8) >> 4;
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snvdbg("Compensated temperature = %d\n", temp);
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/* Calculate true pressure */
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b6 = b5 - 4000;
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x1 = (priv->bmp180_cal_b2 * ((b6 * b6) >> 12)) >> 11;
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x2 = (priv->bmp180_cal_ac2 * b6) >> 11;
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x3 = x1 + x2;
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b3 = (((((int32_t) priv->bmp180_cal_ac1) * 4 + x3) << oss) + 2) >> 2;
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x1 = (priv->bmp180_cal_ac3 * b6) >> 13;
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x2 = (priv->bmp180_cal_b1 * ((b6 * b6) >> 12)) >> 16;
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x3 = ((x1 + x2) + 2) >> 2;
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b4 = (priv->bmp180_cal_ac4 * (uint32_t) (x3 + 32768)) >> 15;
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b7 = ((uint32_t) (priv->bmp180_upress - b3) * (50000 >> oss));
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if (b7 < 0x80000000)
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{
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press = (b7 << 1) / b4;
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}
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else
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{
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press = (b7 / b4) << 1;
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}
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x1 = (press >> 8) * (press >> 8);
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x1 = (x1 * 3038) >> 16;
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x2 = (-7357 * press) >> 16;
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press = press + ((x1 + x2 + 3791) >> 4);
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snvdbg("Compressed pressure = %d\n", press);
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return press;
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}
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/****************************************************************************
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* Name: bmp180_open
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*
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* Description:
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* This function is called whenever the BMP1801 device is opened.
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*
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****************************************************************************/
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static int bmp180_open(FAR struct file *filep)
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{
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return OK;
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}
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|
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/****************************************************************************
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|
* Name: bmp180_close
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*
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* Description:
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* This routine is called when the BMP180 device is closed.
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*
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|
****************************************************************************/
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|
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static int bmp180_close(FAR struct file *filep)
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{
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return OK;
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}
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|
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/****************************************************************************
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* Name: bmp180_read
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****************************************************************************/
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static ssize_t bmp180_read(FAR struct file *filep, FAR char *buffer,
|
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size_t buflen)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct bmp180_dev_s *priv = inode->i_private;
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FAR uint32_t *press = (FAR uint32_t *) buffer;
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if (!buffer)
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{
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sndbg("Buffer is null\n");
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return -1;
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|
}
|
|
|
|
if (buflen != 4)
|
|
{
|
|
sndbg("You can't read something other than 32 bits (4 bytes)\n");
|
|
return -1;
|
|
}
|
|
|
|
/* Get the pressure compensated */
|
|
|
|
*press = (int32_t) bmp180_getpressure(priv);
|
|
|
|
/* Return size of uint32_t (4 bytes) */
|
|
|
|
return 4;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: bmp180_write
|
|
****************************************************************************/
|
|
|
|
static ssize_t bmp180_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t buflen)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: bmp180_register
|
|
*
|
|
* Description:
|
|
* Register the BMP180 character device as 'devpath'
|
|
*
|
|
* Input Parameters:
|
|
* devpath - The full path to the driver to register. E.g., "/dev/press0"
|
|
* i2c - An instance of the I2C interface to use to communicate with
|
|
* BMP180
|
|
*
|
|
* Returned Value:
|
|
* Zero (OK) on success; a negated errno value on failure.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int bmp180_register(FAR const char *devpath, FAR struct i2c_dev_s *i2c)
|
|
{
|
|
FAR struct bmp180_dev_s *priv;
|
|
int ret;
|
|
|
|
/* Initialize the BMP180 device structure */
|
|
|
|
priv = (FAR struct bmp180_dev_s *)kmm_malloc(sizeof(struct bmp180_dev_s));
|
|
if (!priv)
|
|
{
|
|
sndbg("Failed to allocate instance\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
priv->i2c = i2c;
|
|
priv->addr = BMP180_ADDR;
|
|
priv->freq = BMP180_FREQ;
|
|
|
|
/* Configure I2C before using it */
|
|
|
|
I2C_SETADDRESS(priv->i2c, priv->addr, 7);
|
|
I2C_SETFREQUENCY(priv->i2c, priv->freq);
|
|
|
|
/* Check Device ID */
|
|
|
|
ret = bmp180_checkid(priv);
|
|
if (ret < 0)
|
|
{
|
|
sndbg("Failed to register driver: %d\n", ret);
|
|
kmm_free(priv);
|
|
return ret;
|
|
}
|
|
|
|
/* Read the coefficient value */
|
|
|
|
bmp180_updatecaldata(priv);
|
|
|
|
/* Register the character driver */
|
|
|
|
ret = register_driver(devpath, &g_bmp180fops, 0666, priv);
|
|
if (ret < 0)
|
|
{
|
|
sndbg("Failed to register driver: %d\n", ret);
|
|
kmm_free(priv);
|
|
}
|
|
|
|
snvdbg("BMP180 driver loaded successfully!\n");
|
|
return ret;
|
|
}
|
|
|
|
#endif /* CONFIG_I2C && CONFIG_BMP180 */
|