/****************************************************************************
* drivers/sensors/veml6070.c
* Character driver for the Vishay UV-A Light Sensor VEML6070
*
* 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/signal.h>
#include <nuttx/random.h>
#include <nuttx/fs/fs.h>
#include <nuttx/i2c/i2c_master.h>
#include <nuttx/sensors/veml6070.h>
#if defined(CONFIG_I2C) && defined(CONFIG_SENSORS_VEML6070)
/****************************************************************************
* Pre-process Definitions
****************************************************************************/
#ifndef CONFIG_VEML6070_I2C_FREQUENCY
# define CONFIG_VEML6070_I2C_FREQUENCY 100000
#endif
/****************************************************************************
* Private Types
****************************************************************************/
struct veml6070_dev_s
{
FAR struct i2c_master_s *i2c; /* I2C interface */
uint8_t addr; /* I2C address */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* I2C Helpers */
static int veml6070_read8(FAR struct veml6070_dev_s *priv, int offset,
FAR uint8_t *regval);
static int veml6070_write8(FAR struct veml6070_dev_s *priv,
uint8_t regval);
/* Character driver methods */
static int veml6070_open(FAR struct file *filep);
static int veml6070_close(FAR struct file *filep);
static ssize_t veml6070_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t veml6070_write(FAR struct file *filep,
FAR const char *buffer, size_t buflen);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations g_veml6070_fops =
{
veml6070_open, /* open */
veml6070_close, /* close */
veml6070_read, /* read */
veml6070_write, /* write */
NULL, /* seek */
NULL, /* ioctl */
NULL /* poll */
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
, NULL /* unlink */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: veml6070_read8
*
* Description:
* Read 8-bit register
*
****************************************************************************/
static int veml6070_read8(FAR struct veml6070_dev_s *priv, int offset,
FAR uint8_t *regval)
{
struct i2c_config_s config;
uint8_t data[1];
int ret = -1;
/* Set up the I2C configuration */
config.frequency = CONFIG_VEML6070_I2C_FREQUENCY;
config.address = priv->addr + offset;
config.addrlen = 7;
/* Read 8-bits from the device */
ret = i2c_read(priv->i2c, &config, data, 1);
if (ret < 0)
{
snerr ("i2c_read failed: %d\n", ret);
return ret;
}
/* Copy the content of the buffer to the location of the uint8_t pointer */
*regval = data[0];
sninfo("value: %08x ret: %d\n", *regval, ret);
return OK;
}
/****************************************************************************
* Name: veml6070_write8
*
* Description:
* Write from an 8-bit register
*
****************************************************************************/
static int veml6070_write8(FAR struct veml6070_dev_s *priv, uint8_t regval)
{
struct i2c_config_s config;
int ret;
sninfo("value: %02x\n", regval);
/* Set up the I2C configuration */
config.frequency = CONFIG_VEML6070_I2C_FREQUENCY;
config.address = priv->addr;
config.addrlen = 7;
/* Write 8 bits to device */
ret = i2c_write(priv->i2c, &config, ®val, 1);
if (ret < 0)
{
snerr("ERROR: i2c_write failed: %d\n", ret);
}
return ret;
}
/****************************************************************************
* Name: veml6070_open
*
* Description:
* This function is called whenever the VEML6070 device is opened.
*
****************************************************************************/
static int veml6070_open(FAR struct file *filep)
{
return OK;
}
/****************************************************************************
* Name: veml6070_close
*
* Description:
* This routine is called when the VEML6070 device is closed.
*
****************************************************************************/
static int veml6070_close(FAR struct file *filep)
{
return OK;
}
/****************************************************************************
* Name: veml6070_read
****************************************************************************/
static ssize_t veml6070_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
int ret;
FAR struct inode *inode;
FAR struct veml6070_dev_s *priv;
int msb = 1;
uint16_t regdata;
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
priv = (FAR struct veml6070_dev_s *)inode->i_private;
/* Check if the user is reading the right size */
if (buflen != 2)
{
snerr("ERROR: You need to read 2 bytes from this sensor!\n");
return -EINVAL;
}
/* Enable the sensor */
ret = veml6070_write8(priv, VEML6070_CMD_RSV & ~VEML6070_CMD_SD);
if (ret < 0)
{
snerr("ERROR: Failed to enable the VEML6070!\n");
return -EINVAL;
}
/* 1T for Rset 270Kohms is 125ms */
nxsig_usleep(125000);
/* Read the MSB first */
ret = veml6070_read8(priv, msb, (FAR uint8_t *) ®data);
if (ret < 0)
{
snerr("ERROR: Error reading light sensor!\n");
return ret;
}
buffer[1] = regdata;
/* Read the LSB */
msb = 0;
ret = veml6070_read8(priv, msb, (FAR uint8_t *) ®data);
if (ret < 0)
{
snerr("ERROR: Error reading light sensor!\n");
return ret;
}
buffer[0] = regdata;
/* Feed sensor data to entropy pool */
add_sensor_randomness((buffer[1] << 16) ^ buffer[0]);
return buflen;
}
/****************************************************************************
* Name: veml6070_write
****************************************************************************/
static ssize_t veml6070_write(FAR struct file *filep,
FAR const char *buffer, size_t buflen)
{
return -ENOSYS;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: veml6070_register
*
* Description:
* Register the VEML6070 character device as 'devpath'
*
* Input Parameters:
* devpath - The full path to the driver to register. E.g., "/dev/uvlight0"
* i2c - An instance of the I2C interface to use to communicate with VEML6070
* addr - The I2C address of the VEML6070.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int veml6070_register(FAR const char *devpath, FAR struct i2c_master_s *i2c,
uint8_t addr)
{
int ret;
/* Sanity check */
DEBUGASSERT(i2c != NULL);
/* Initialize the VEML6070 device structure */
FAR struct veml6070_dev_s *priv =
(FAR struct veml6070_dev_s *)kmm_malloc(sizeof(struct veml6070_dev_s));
if (priv == NULL)
{
snerr("ERROR: Failed to allocate instance\n");
return -ENOMEM;
}
priv->i2c = i2c;
priv->addr = addr;
/* Initialize the device (shut it down) */
ret = veml6070_write8(priv, VEML6070_CMD_RSV | VEML6070_CMD_SD);
if (ret < 0)
{
snerr("ERROR: Failed to initialize the VEML6070!\n");
return ret;
}
/* Register the character driver */
ret = register_driver(devpath, &g_veml6070_fops, 0666, priv);
if (ret < 0)
{
snerr("ERROR: Failed to register driver: %d\n", ret);
kmm_free(priv);
}
return ret;
}
#endif /* CONFIG_I2C && CONFIG_SENSORS_VEML6070 */