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incubator-nuttx/drivers/sensors/adt7320.c

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/****************************************************************************
* drivers/sensors/adt7320.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdlib.h>
#include <fixedmath.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include <nuttx/spi/spi.h>
#include <nuttx/sensors/adt7320.h>
#include <nuttx/random.h>
#include "adt7320.h"
#if defined(CONFIG_SPI) && defined(CONFIG_SENSORS_ADT7320)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_ADT7320_SPI_FREQUENCY
# define CONFIG_ADT7320_SPI_FREQUENCY 1000000
#endif
#define ADT7320_SPI_MODE (SPIDEV_MODE3) /* SPI Mode 3: CPOL=1,CPHA=1 */
/* Centigrade to Fahrenheit conversion: F = 9*C/5 + 32 */
#define B16_9DIV5 (9 * 65536 / 5)
#define B16_32 (32 * 65536)
/****************************************************************************
* Private
****************************************************************************/
struct adt7320_dev_s
{
FAR struct spi_dev_s *spi; /* Saved SPI driver instance */
int spidev;
bool fahrenheit; /* true: temperature will be reported in
* fahrenheit */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* SPI Helpers */
static void adt7320_write_reg16(FAR struct adt7320_dev_s *priv,
uint8_t reg,
uint16_t data);
static uint16_t adt7320_read_reg16(FAR struct adt7320_dev_s *priv,
uint8_t reg);
static void adt7320_write_reg8(FAR struct adt7320_dev_s *priv,
uint8_t reg,
uint8_t data);
static uint8_t adt7320_read_reg8(FAR struct adt7320_dev_s *priv,
uint8_t reg);
static int adt7320_readtemp(FAR struct adt7320_dev_s *priv, FAR b16_t *temp);
/* Character driver methods */
static int adt7320_open(FAR struct file *filep);
static ssize_t adt7320_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t adt7320_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
static int adt7320_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations g_adt7320fops =
{
adt7320_open, /* open */
NULL, /* close */
adt7320_read, /* read */
adt7320_write, /* write */
NULL, /* seek */
adt7320_ioctl, /* ioctl */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: adt7320_configspi
*
* Description:
* Configure the SPI interface to match the serial interface specification
* of the ADT7320.
*
****************************************************************************/
static inline void adt7320_configspi(FAR struct spi_dev_s *spi)
{
/* Configure SPI for the ADT7320 */
SPI_SETMODE(spi, ADT7320_SPI_MODE);
SPI_SETBITS(spi, 8);
SPI_HWFEATURES(spi, 0);
SPI_SETFREQUENCY(spi, CONFIG_ADT7320_SPI_FREQUENCY);
}
/****************************************************************************
* Name: adt7320_write_reg16
*
* Description:
* Write to a 16-bit register (ADT7320_TEMP_REG, ADT7320_TCRIT_REG,
* ADT7320_THIGH_REG or ADT7320_TLOW_REG).
*
****************************************************************************/
static void adt7320_write_reg16(FAR struct adt7320_dev_s *priv,
uint8_t reg,
const uint16_t data)
{
SPI_LOCK(priv->spi, true);
adt7320_configspi(priv->spi);
SPI_SELECT(priv->spi, priv->spidev, true);
SPI_SEND(priv->spi, (reg & 0x07) << 3);
SPI_SEND(priv->spi, data >> 8);
SPI_SEND(priv->spi, data & 0xff);
SPI_SELECT(priv->spi, priv->spidev, false);
SPI_LOCK(priv->spi, false);
}
/****************************************************************************
* Name: adt7320_read_reg16
*
* Description:
* Read a 16-bit register (ADT7320_TEMP_REG, ADT7320_TCRIT_REG,
* ADT7320_THIGH_REG or ADT7320_TLOW_REG).
*
****************************************************************************/
static uint16_t adt7320_read_reg16(FAR struct adt7320_dev_s *priv,
uint8_t reg)
{
uint8_t data[2];
SPI_LOCK(priv->spi, true);
adt7320_configspi(priv->spi);
SPI_SELECT(priv->spi, priv->spidev, true);
SPI_SEND(priv->spi, ((reg & 0x07) << 3) | (1 << 6));
SPI_RECVBLOCK(priv->spi, data, 2);
SPI_SELECT(priv->spi, priv->spidev, false);
SPI_LOCK(priv->spi, false);
return (data[0] << 8) | data[1];
}
/****************************************************************************
* Name: adt7320_write_reg8
*
* Description:
* Write to a 8-bit register (ADT7320_STAT_REG, ADT7320_TCRIT_REG,
* ADT7320_CONF_REG, ADT7320_ID_REG or ADT7320_THYST_REG).
****************************************************************************/
static void adt7320_write_reg8(FAR struct adt7320_dev_s *priv,
uint8_t reg,
const uint8_t data)
{
SPI_LOCK(priv->spi, true);
adt7320_configspi(priv->spi);
SPI_SELECT(priv->spi, priv->spidev, true);
SPI_SEND(priv->spi, (reg & 0x07) << 3);
SPI_SEND(priv->spi, data);
SPI_SELECT(priv->spi, priv->spidev, false);
SPI_LOCK(priv->spi, false);
}
/****************************************************************************
* Name: adt7320_read_reg8
*
* Description:
* Read a 8-bit register (ADT7320_STAT_REG, ADT7320_TCRIT_REG,
* ADT7320_CONF_REG, ADT7320_ID_REG or ADT7320_THYST_REG).
****************************************************************************/
static uint8_t adt7320_read_reg8(FAR struct adt7320_dev_s *priv,
uint8_t reg)
{
uint8_t data;
SPI_LOCK(priv->spi, true);
adt7320_configspi(priv->spi);
SPI_SELECT(priv->spi, priv->spidev, true);
SPI_SEND(priv->spi, ((reg & 0x07) << 3) | (1 << 6));
SPI_RECVBLOCK(priv->spi, &data, 1);
SPI_SELECT(priv->spi, priv->spidev, false);
SPI_LOCK(priv->spi, false);
return data;
}
/****************************************************************************
* Name: adt7320_reset
*
* Description:
* Reset the ADT7320, you should wait at least 500us before trying to
* access the sensor again.
*
****************************************************************************/
static void adt7320_reset(FAR struct adt7320_dev_s *priv)
{
SPI_LOCK(priv->spi, true);
adt7320_configspi(priv->spi);
SPI_SELECT(priv->spi, priv->spidev, true);
SPI_SEND(priv->spi, 0xff);
SPI_SEND(priv->spi, 0xff);
SPI_SEND(priv->spi, 0xff);
SPI_SEND(priv->spi, 0xff);
SPI_SELECT(priv->spi, priv->spidev, false);
SPI_LOCK(priv->spi, false);
}
/****************************************************************************
* Name: adt7320_readtemp
*
* Description:
* Read the temperature register with special scaling (ADT7320_TEMP_REG).
*
****************************************************************************/
static int adt7320_readtemp(FAR struct adt7320_dev_s *priv, FAR b16_t *temp)
{
b16_t temp16;
int16_t temp_raw;
/* Read the raw temperature data (b16_t) */
temp_raw = (int16_t)adt7320_read_reg16(priv, ADT7320_TEMP_REG) & 0xfff8;
/* Convert from 9.7 bits to 16.16 bits */
temp16 = (int32_t)temp_raw << 9;
add_sensor_randomness(temp16);
sninfo("Centigrade: %08x\n", temp16);
/* Was fahrenheit requested? */
if (priv->fahrenheit)
{
/* Centigrade to Fahrenheit conversion: F = 9*C/5 + 32 */
temp16 = b16mulb16(temp16, B16_9DIV5) + B16_32;
sninfo("Fahrenheit: %08x\n", temp16);
}
*temp = temp16;
return OK;
}
/****************************************************************************
* Name: adt7320_open
*
* Description:
* This function is called whenever the ADT7320 device is opened.
*
****************************************************************************/
static int adt7320_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct adt7320_dev_s *priv = inode->i_private;
if (adt7320_read_reg8(priv, ADT7320_ID_REG) != ADT7320_ID)
{
return -ENODEV;
}
return OK;
}
/****************************************************************************
* Name: adt7320_read
****************************************************************************/
static ssize_t adt7320_read(FAR struct file *filep,
FAR char *buffer, size_t buflen)
{
FAR struct inode *inode = filep->f_inode;
FAR struct adt7320_dev_s *priv = inode->i_private;
FAR b16_t *ptr;
ssize_t nsamples;
int i;
int ret;
/* How many samples were requested to get? */
nsamples = buflen / sizeof(b16_t);
ptr = (FAR b16_t *)buffer;
sninfo("buflen: %d nsamples: %d\n", buflen, nsamples);
/* Get the requested number of samples */
for (i = 0; i < nsamples; i++)
{
b16_t temp = 0;
/* Read the next b16_t temperature value */
ret = adt7320_readtemp(priv, &temp);
if (ret < 0)
{
snerr("ERROR: adt7320_readtemp failed: %d\n", ret);
return (ssize_t)ret;
}
/* Save the temperature value in the user buffer */
*ptr++ = temp;
}
return nsamples * sizeof(b16_t);
}
/****************************************************************************
* Name: adt7320_write
****************************************************************************/
static ssize_t adt7320_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen)
{
return -ENOSYS;
}
/****************************************************************************
* Name: adt7320_ioctl
*
* Description:
* Supported IOCTLs:
*
* SNIOC_READSTAT: Read the status register, treat arg as an
* uint8_t pointer.
*
* SNIOC_READCONF: Read the configuration register, treat arg as
* an uint8_t pointer.
*
* SNIOC_WRITECONF: Write to the configuration register, treat arg
* as an uint8_t value.
*
* SNIOC_FAHRENHEIT: Report samples in Fahrenheit, ignores arg.
*
* SNIOC_CENTIGRADE: Report samples in Celsius, ignores arg.
*
* SNIOC_READTCRIT: Read the critical temperature register, treat
* arg as an b16_t pointer.
*
* SNIOC_WRITETCRIT: Write to the critical temperature register,
* treat arg as an b16_t value.
*
* SNIOC_READTHYS: Read the hysteresis temperature register, treat
* arg as an b16_t pointer.
*
* SNIOC_WRITETHYS: Write to the hysteresis temperature register,
* treat arg as an b16_t value.
*
* SNIOC_READTLOW: Read the low temperature register, treat arg as
* an b16_t pointer.
*
* SNIOC_WRITETLOW: Write to the low temperature register, treat
* arg as an b16_t value.
*
* SNIOC_READTHIGH: Read the high temperature register, treat arg
* as an b16_t pointer.
*
* SNIOC_WRITETHIGH: Write to the high temperature register, treat
* arg as an b16_t value.
*
****************************************************************************/
static int adt7320_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct adt7320_dev_s *priv = inode->i_private;
int ret = OK;
switch (cmd)
{
/* Read the status register. Arg: uint8_t* pointer */
case SNIOC_READSTAT:
{
FAR uint8_t *ptr = (FAR uint8_t *)((uintptr_t)arg);
DEBUGASSERT(ptr != NULL);
*ptr = adt7320_read_reg8(priv, ADT7320_STAT_REG);
}
break;
/* Read the configuration register. Arg: uint8_t* pointer */
case SNIOC_READCONF:
{
FAR uint8_t *ptr = (FAR uint8_t *)((uintptr_t)arg);
DEBUGASSERT(ptr != NULL);
*ptr = adt7320_read_reg8(priv, ADT7320_CONF_REG);
}
break;
/* Write to the configuration register. Arg: uint8_t value */
case SNIOC_WRITECONF:
adt7320_write_reg8(priv, ADT7320_CONF_REG, (uint8_t)arg);
break;
/* Report samples in Fahrenheit */
case SNIOC_FAHRENHEIT:
priv->fahrenheit = true;
sninfo("Fahrenheit\n");
break;
/* Report samples in Celsius */
case SNIOC_CENTIGRADE:
priv->fahrenheit = false;
sninfo("Celsius\n");
break;
/* Read the critical temperature register. Arg: b16_t* pointer */
case SNIOC_READTCRIT:
{
FAR b16_t *ptr = (FAR b16_t *)((uintptr_t)arg);
int16_t temp_raw;
DEBUGASSERT(ptr != NULL);
temp_raw = adt7320_read_reg16(priv, ADT7320_TCRIT_REG);
*ptr = b8tob16(temp_raw << 1);
}
break;
/* Write to the critical temperature register. Arg: b16_t value */
case SNIOC_WRITETCRIT:
adt7320_write_reg16(priv, ADT7320_TCRIT_REG,
b16tob8((b16_t)arg) >> 1);
break;
/* Read the hysteresis temperature register. Arg: b16_t* */
case SNIOC_READTHYS:
{
FAR b16_t *ptr = (FAR b16_t *)((uintptr_t)arg);
uint8_t tmp;
DEBUGASSERT(ptr != NULL);
tmp = adt7320_read_reg8(priv, ADT7320_THYST_REG);
*ptr = uitoub16(tmp);
}
break;
/* Write to the hysteresis temperature register. Arg: b16_t value */
case SNIOC_WRITETHYS:
adt7320_write_reg8(priv, ADT7320_THYST_REG, ub16toi((b16_t)arg));
break;
/* Read the low temperature register. Arg: b16_t* pointer */
case SNIOC_READTLOW:
{
FAR b16_t *ptr = (FAR b16_t *)((uintptr_t)arg);
int16_t temp_raw;
DEBUGASSERT(ptr != NULL);
temp_raw = adt7320_read_reg16(priv, ADT7320_TLOW_REG);
*ptr = b8tob16(temp_raw << 1);
}
break;
/* Write to the low temperature register. Arg: b16_t value */
case SNIOC_WRITETLOW:
adt7320_write_reg16(priv, ADT7320_TLOW_REG,
b16tob8((b16_t)arg) >> 1);
break;
/* Read the high temperature register. Arg: b16_t* pointer */
case SNIOC_READTHIGH:
{
FAR b16_t *ptr = (FAR b16_t *)((uintptr_t)arg);
int16_t temp_raw;
DEBUGASSERT(ptr != NULL);
temp_raw = adt7320_read_reg16(priv, ADT7320_THIGH_REG);
*ptr = b8tob16(temp_raw << 1);
}
break;
/* Write to the high temperature register. Arg: b16_t value */
case SNIOC_WRITETHIGH:
adt7320_write_reg16(priv, ADT7320_THIGH_REG,
b16tob8((b16_t)arg) >> 1);
break;
default:
sninfo("Unrecognized cmd: %d\n", cmd);
ret = -ENOTTY;
break;
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: adt7320_register
*
* Description:
* Register the ADT7320 character device as 'devpath'
*
* Input Parameters:
* devpath - The full path to the driver to register. E.g., "/dev/temp0"
* spi - An instance of the SPI bus to use to communicate with ADT7320
* spidev - The SPI device number used to select the correct CS line
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int adt7320_register(FAR const char *devpath,
FAR struct spi_dev_s *spi, int spidev)
{
FAR struct adt7320_dev_s *priv;
int ret;
/* Sanity check */
DEBUGASSERT(spi != NULL);
/* Initialize the ADT7320 device structure */
priv = kmm_malloc(sizeof(struct adt7320_dev_s));
if (priv == NULL)
{
snerr("ERROR: Failed to allocate instance\n");
return -ENOMEM;
}
priv->spi = spi;
priv->spidev = spidev;
priv->fahrenheit = false;
/* Register the character driver */
ret = register_driver(devpath, &g_adt7320fops, 0666, priv);
if (ret < 0)
{
snerr("ERROR: Failed to register driver: %d\n", ret);
kmm_free(priv);
}
/* Reset the ADT7320 SPI interface */
adt7320_reset(priv);
return ret;
}
#endif /* CONFIG_SPI && CONFIG_SENSORS_ADT7320 */
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