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nuttx/drivers/sensors/bh1750fvi.c

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/****************************************************************************
* drivers/sensors/bh1750fvi.c
* Character driver for the Rohm Ambient Light Sensor BH1750FVI
*
* Copyright (C) 2015-2016 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Copyright (C) 2016 Alan Carvalho de Assis. All rights reserved.
* Author: Alan Carvalho de Assis <acassis@gmail.com>
*
* 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/i2c/i2c_master.h>
#include <nuttx/sensors/bh1750fvi.h>
#if defined(CONFIG_I2C) && defined(CONFIG_BH1750FVI)
/****************************************************************************
* Pre-process Definitions
****************************************************************************/
#ifndef CONFIG_BH1750FVI_I2C_FREQUENCY
# define CONFIG_BH1750FVI_I2C_FREQUENCY 400000
#endif
/****************************************************************************
* Private Types
****************************************************************************/
struct bh1750fvi_dev_s
{
FAR struct i2c_master_s *i2c; /* I2C interface */
uint8_t addr; /* I2C address */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* I2C Helpers */
static int bh1750fvi_read16(FAR struct bh1750fvi_dev_s *priv,
FAR uint16_t *regval);
static int bh1750fvi_write8(FAR struct bh1750fvi_dev_s *priv,
uint8_t regval);
/* Character driver methods */
static int bh1750fvi_open(FAR struct file *filep);
static int bh1750fvi_close(FAR struct file *filep);
static ssize_t bh1750fvi_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t bh1750fvi_write(FAR struct file *filep,
FAR const char *buffer, size_t buflen);
static int bh1750fvi_ioctl(FAR struct file *filep, int cmd,
unsigned long arg);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations g_bh1750fvi_fops =
{
bh1750fvi_open, /* open */
bh1750fvi_close, /* close */
bh1750fvi_read, /* read */
bh1750fvi_write, /* write */
NULL, /* seek */
bh1750fvi_ioctl /* ioctl */
#ifndef CONFIG_DISABLE_POLL
, NULL /* poll */
#endif
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
, NULL /* unlink */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: bh1750fvi_read16
*
* Description:
* Read 16-bit register
*
****************************************************************************/
static int bh1750fvi_read16(FAR struct bh1750fvi_dev_s *priv,
FAR uint16_t *regval)
{
struct i2c_config_s config;
uint8_t buffer[2];
int ret = -1;
/* Set up the I2C configuration */
config.frequency = CONFIG_BH1750FVI_I2C_FREQUENCY;
config.address = priv->addr;
config.addrlen = 7;
/* Read 16-bits from the device */
ret = i2c_read(priv->i2c, &config, buffer, 2);
if (ret < 0)
{
snerr ("i2c_read failed: %d\n", ret);
return ret;
}
/* Copy the content of the buffer to the location of the uint16_t pointer */
*regval = (uint16_t)((buffer[0]<<8) | (buffer[1]));
snerr("value: %08x ret: %d\n", *regval, ret);
return OK;
}
/****************************************************************************
* Name: bh1750fvi_write8
*
* Description:
* Write from an 8-bit register
*
****************************************************************************/
static int bh1750fvi_write8(FAR struct bh1750fvi_dev_s *priv, uint8_t regval)
{
struct i2c_config_s config;
int ret;
snerr("value: %02x\n", regval);
/* Set up the I2C configuration */
config.frequency = CONFIG_BH1750FVI_I2C_FREQUENCY;
config.address = priv->addr;
config.addrlen = 7;
/* Write 8 bits to device */
ret = i2c_write(priv->i2c, &config, &regval, 1);
if (ret < 0)
{
snerr("i2c_write failed: %d\n", ret);
}
return ret;
}
/****************************************************************************
* Name: bh1750fvi_open
*
* Description:
* This function is called whenever the BH1750FVI device is opened.
*
****************************************************************************/
static int bh1750fvi_open(FAR struct file *filep)
{
return OK;
}
/****************************************************************************
* Name: bh1750fvi_close
*
* Description:
* This routine is called when the BH1750FVI device is closed.
*
****************************************************************************/
static int bh1750fvi_close(FAR struct file *filep)
{
return OK;
}
/****************************************************************************
* Name: bh1750fvi_read
****************************************************************************/
static ssize_t bh1750fvi_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
int ret;
FAR struct inode *inode;
FAR struct bh1750fvi_dev_s *priv;
uint16_t lux = 0;
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
priv = (FAR struct bh1750fvi_dev_s *)inode->i_private;
/* Check if the user is reading the right size */
if (buflen != 2)
{
snerr("You need to read 2 bytes from this sensor!\n");
return -EINVAL;
}
ret = bh1750fvi_read16(priv, &lux);
if (ret < 0)
{
snerr("Error reading light sensor!\n");
return ret;
}
buffer[0] = lux & 0xFF;
buffer[1] = (lux & 0xFF00) >> 8;
return buflen;
}
/****************************************************************************
* Name: bh1750fvi_write
****************************************************************************/
static ssize_t bh1750fvi_write(FAR struct file *filep,
FAR const char *buffer, size_t buflen)
{
return -ENOSYS;
}
/****************************************************************************
* Name: bh1750fvi_ioctl
****************************************************************************/
static int bh1750fvi_ioctl(FAR struct file *filep, int cmd,
unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct bh1750fvi_dev_s *priv = inode->i_private;
int ret = OK;
switch (cmd)
{
/* Set device to Continuously H-Resolution Mode */
case SNIOC_CHRM:
{
ret = bh1750fvi_write8(priv, BH1750FVI_CONTINUOUS_HRM);
if (ret < 0)
{
snerr("Cannot change to Continuously H-Resolution Mode!\n");
}
}
break;
/* Set device to Continuously H-Resolution Mode2 */
case SNIOC_CHRM2:
{
ret = bh1750fvi_write8(priv, BH1750FVI_CONTINUOUS_HRM2);
if (ret < 0)
{
snerr("Cannot change to Continuously H-Resolution Mode2!\n");
}
}
break;
/* Set device to Continuously L-Resolution Mode */
case SNIOC_CLRM:
{
ret = bh1750fvi_write8(priv, BH1750FVI_CONTINUOUS_LRM);
if (ret < 0)
{
snerr("Cannot change to Continuously L-Resolution Mode!\n");
}
}
break;
/* Set device to One Time H-Resolution Mode */
case SNIOC_OTHRM:
{
ret = bh1750fvi_write8(priv, BH1750FVI_ONETIME_HRM);
if (ret < 0)
{
snerr("Cannot change to One Time H-Resolution Mode!\n");
}
}
break;
/* Set device to One Time H-Resolution Mode 2 */
case SNIOC_OTHRM2:
{
ret = bh1750fvi_write8(priv, BH1750FVI_ONETIME_HRM2);
if (ret < 0)
{
snerr("Cannot change to One Time H-Resolution Mode2!\n");
}
}
break;
/* Set device to One Time L-Resolution Mode */
case SNIOC_OTLRM:
{
ret = bh1750fvi_write8(priv, BH1750FVI_ONETIME_LRM);
if (ret < 0)
{
snerr("Cannot change to One Time L-Resolution Mode!\n");
}
}
break;
/* Change the Measurement Time */
case SNIOC_CHMEATIME:
{
FAR uint8_t *ptr = (FAR uint8_t *)((uintptr_t)arg);
uint8_t reg;
DEBUGASSERT(ptr != NULL);
reg = BH1750FVI_MEASURE_TIMEH | ((*ptr & 0xE0) >> 5);
ret = bh1750fvi_write8(priv, reg);
if (ret < 0)
{
snerr("Cannot Change Measure Time at MEASURE_TIMEH!\n");
}
reg = BH1750FVI_MEASURE_TIMEL | (*ptr & 0x1F);
ret = bh1750fvi_write8(priv, reg);
if (ret < 0)
{
snerr("Cannot Change Measure Time at MEASURE_TIMEL!\n");
}
}
break;
default:
snerr("Unrecognized cmd: %d\n", cmd);
ret = -ENOTTY;
break;
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: bh1750fvi_register
*
* Description:
* Register the BH1750FVI character device as 'devpath'
*
* Input Parameters:
* devpath - The full path to the driver to register. E.g., "/dev/light0"
* i2c - An instance of the I2C interface to use to communicate with BH1750FVI
* addr - The I2C address of the BH1750FVI.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int bh1750fvi_register(FAR const char *devpath, FAR struct i2c_master_s *i2c,
uint8_t addr)
{
int ret;
/* Sanity check */
DEBUGASSERT(i2c != NULL);
/* Initialize the BH1750FVI device structure */
FAR struct bh1750fvi_dev_s *priv =
(FAR struct bh1750fvi_dev_s *)kmm_malloc(sizeof(struct bh1750fvi_dev_s));
if (priv == NULL)
{
snerr("Failed to allocate instance\n");
return -ENOMEM;
}
priv->i2c = i2c;
priv->addr = addr;
/* Power on the device */
ret = bh1750fvi_write8(priv, BH1750FVI_POWERON);
if (ret < 0)
{
snerr("Failed to power-on the BH1750FVI!\n");
return ret;
}
/* Set Continuosly H-Resolution Mode */
ret = bh1750fvi_write8(priv, BH1750FVI_CONTINUOUS_HRM);
if (ret < 0)
{
snerr("Failed to enable the Continuosly H-Resolution Mode!\n");
return ret;
}
/* Register the character driver */
ret = register_driver(devpath, &g_bh1750fvi_fops, 0666, priv);
if (ret < 0)
{
snerr("Failed to register driver: %d\n", ret);
kmm_free(priv);
}
return ret;
}
#endif /* CONFIG_I2C && CONFIG_BH1750FVI */
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