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drivers/analog/ads7046: Add support for ADS7046 ADC

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Add support for the Texas Instruments ADS7046 12-bit, SPI-compatible ADC.

Signed-off-by: Niccolò Maggioni <nicco.maggioni+nuttx@gmail.com>
This commit is contained in:
Niccolò Maggioni 2025-08-11 14:22:16 +02:00 • committed by Xiang Xiao
parent f43c943ebe
commit 7a2343f1be
6 changed files with 395 additions and 4 deletions
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4
drivers/analog/CMakeLists.txt
View file

@ -109,6 +109,10 @@ if(CONFIG_ADC)
if(CONFIG_ADC_ADS1115)
list(APPEND SRCS ads1115.c)
endif()
if(CONFIG_ADC_ADS7046)
list(APPEND SRCS ads7046.c)
endif()
endif()
if(CONFIG_LMP92001)

25
drivers/analog/Kconfig
View file

@ -257,6 +257,23 @@ config ADC_MCP3008_DIFFERENTIAL
endif # ADC_MCP3008
config ADC_ADS7046
bool "TI ADS7046 support"
default n
select SPI
---help---
Enable driver support for the Texas Instruments ADS7046 12-bit ADC.
if ADC_ADS7046
config ADS7046_FREQUENCY
int "TI ADS7046 SPI frequency"
default 1000000
---help---
ADS7046 SPI frequency. Maximum is 60 MHz.
endif # ADC_ADS7046
config ADC_ADS1115
bool "ADS1115 support"
default n
@ -264,15 +281,15 @@ config ADC_ADS1115
---help---
Enable driver support for the Texas Instruments ADS1115 16-bit ADC.
Currently support is experimental, especially the comparator and ALRT/RDY
pin functions.
pin functions.
if ADC_ADS1115
if ADC_ADS1115
config ADC_ADS1115_I2C_FREQUENCY
int "ADS1115 I2C frequency"
default 100000
---help---
ADS1115 I2C frequency.
ADS1115 I2C frequency.
config ADC_ADS1115_ADDR
hex "ADS1115 I2C address"
@ -320,7 +337,7 @@ config ADC_ADS1115_COMP_MODE
bool "ADS1115 window comparator mode"
default n
---help---
ADS1115 window comparator mode.
ADS1115 window comparator mode.
config ADC_ADS1115_COMP_POL
bool "ADS1115 comparator polarity"

4
drivers/analog/Make.defs
View file

@ -121,6 +121,10 @@ endif
ifeq ($(CONFIG_ADC_ADS1115),y)
CSRCS += ads1115.c
endif
ifeq ($(CONFIG_ADC_ADS7046),y)
CSRCS += ads7046.c
endif
endif
ifeq ($(CONFIG_LMP92001),y)

282
drivers/analog/ads7046.c Normal file
View file

@ -0,0 +1,282 @@
/****************************************************************************
* drivers/analog/ads7046.c
*
* SPDX-License-Identifier: Apache-2.0
*
* 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 <sys/types.h>
#include <sys/ioctl.h>
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/analog/adc.h>
#include <nuttx/analog/ioctl.h>
#include <nuttx/analog/ads7046.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Device uses SPI Mode 1: CKPOL = 0, CKPHA = 1 */
#define ADS7046_SPI_MODE (SPIDEV_MODE1)
#define ADS7046_SPI_BITS 16
/****************************************************************************
* Private Types
****************************************************************************/
struct ads7046_dev_s
{
FAR struct spi_dev_s *spi;
int devno;
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* SPI Helpers */
static void ads7046_lock(FAR struct spi_dev_s *spi);
static void ads7046_unlock(FAR struct spi_dev_s *spi);
/* Character driver methods */
static int ads7046_open(FAR struct file *filep);
static int ads7046_close(FAR struct file *filep);
static int ads7046_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations ads7046_fops =
{
ads7046_open, /* open */
ads7046_close, /* close */
NULL, /* read */
NULL, /* write */
NULL, /* seek */
ads7046_ioctl, /* ioctl */
};
/****************************************************************************
* Private Functions
****************************************************************************/
static void ads7046_lock(FAR struct spi_dev_s *spi)
{
SPI_LOCK(spi, true);
}
static void ads7046_unlock(FAR struct spi_dev_s *spi)
{
SPI_LOCK(spi, false);
}
static void ads7046_config_spi(FAR struct spi_dev_s *spi)
{
SPI_SETMODE(spi, ADS7046_SPI_MODE);
SPI_SETBITS(spi, ADS7046_SPI_BITS);
SPI_HWFEATURES(spi, 0);
SPI_SETFREQUENCY(spi, CONFIG_ADS7046_FREQUENCY);
}
static int ads7046_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct ads7046_dev_s *priv = inode->i_private;
ads7046_config_spi(priv->spi);
up_mdelay(100);
return OK;
}
static int ads7046_close(FAR struct file *filep)
{
UNUSED(filep);
return OK;
}
/* As per the datasheet, the ADS7046 returns the following readings:
* INPUT VOLTAGE (AINP - AINM) DESCRIPTION HEX
* -------------------------------------- ------------------------ ---
* <= 1 LSB Negative full-scale code 000
* 1 LSB to 2 LSB - 001
* V_REF / 2 to V_REF / 2 + 1 LSB Mid code 7FF
* V_REF / 2 + 1 LSB to V_REF / 2 + 2 LSB - 800
* >= V_REF - 1 LSB Positive full-scale code FFF
*/
static void ads7046_read_conversion_result(
FAR const struct ads7046_dev_s *dev, FAR uint16_t *conversion_result,
bool fast_unsafe)
{
*conversion_result = 0;
if (!fast_unsafe)
{
ads7046_lock(dev->spi);
ads7046_config_spi(dev->spi);
}
SPI_SELECT(dev->spi, SPIDEV_ADC(dev->devno), true);
SPI_RECVBLOCK(dev->spi, conversion_result, 1);
SPI_SELECT(dev->spi, SPIDEV_ADC(dev->devno), false);
if (!fast_unsafe)
{
ads7046_unlock(dev->spi);
}
*conversion_result = (*conversion_result & 0b0111111111111000) >> 3;
}
static void ads7046_offset_calibration(FAR const struct ads7046_dev_s *dev)
{
ads7046_lock(dev->spi);
ads7046_config_spi(dev->spi);
SPI_SELECT(dev->spi, SPIDEV_ADC(dev->devno), true);
SPI_SNDBLOCK(dev->spi, 0, 4);
SPI_SELECT(dev->spi, SPIDEV_ADC(dev->devno), false);
ads7046_unlock(dev->spi);
ainfo("requested offset calibration\n");
}
static int ads7046_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct ads7046_dev_s *priv = inode->i_private;
int ret = OK;
switch (cmd)
{
/* Read the result of an analog conversion */
case ANIOC_ADS7046_READ:
{
FAR uint16_t *data = (FAR uint16_t *)((uintptr_t)arg);
ads7046_read_conversion_result(priv, data, false);
break;
}
/* Read the result of an analog conversion (skip SPI locking &
* reconfiguring for faster transfers - HIC SUNT DRACONES!)
*/
case ANIOC_ADS7046_READ_FASTUNSAFE:
{
FAR uint16_t *data = (FAR uint16_t *)((uintptr_t)arg);
ads7046_read_conversion_result(priv, data, true);
break;
}
/* Start an offset calibration */
case ANIOC_ADS7046_OFFCAL:
{
ads7046_offset_calibration(priv);
break;
}
/* Command was not recognized */
default:
{
aerr("ERROR: Unrecognized cmd: %d\n", cmd);
ret = -ENOTTY;
break;
}
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: ads7046_register
*
* Description:
* Register the ADS7046 character device as 'devpath'
*
* Input Parameters:
* devpath - The full path to the driver to register. E.g., "/dev/adc0"
* spi - An instance of the SPI interface to use.
* devno - SPI device number
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int ads7046_register(FAR const char *devpath, FAR struct spi_dev_s *spi,
unsigned int devno)
{
/* Sanity check */
DEBUGASSERT(spi != NULL);
/* Initialize the ADS7046 device structure */
struct ads7046_dev_s *priv = kmm_malloc(sizeof(struct ads7046_dev_s));
if (priv == NULL)
{
aerr("ERROR: Failed to allocate instance %s (%d)\n", strerror(errno),
errno);
return -ENOMEM;
}
priv->spi = spi;
priv->devno = devno;
/* Register the character driver */
int ret = register_driver(devpath, &ads7046_fops, 0666, priv);
if (ret < 0)
{
aerr("ERROR: Failed to register driver: %s (%d)\n", strerror(-ret),
ret);
kmm_free(priv);
}
return ret;
}

79
include/nuttx/analog/ads7046.h Normal file
View file

@ -0,0 +1,79 @@
/****************************************************************************
* include/nuttx/analog/ads7046.h
*
* SPDX-License-Identifier: Apache-2.0
*
* 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.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_ANALOG_ADS7046_H
#define __INCLUDE_NUTTX_ANALOG_ADS7046_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/spi/spi.h>
#include <stdint.h>
#if defined(CONFIG_ADC_ADS7046)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* IOCTL Commands ***********************************************************/
/* Cmd: ANIOC_ADS7046_READ Arg: uint16_t *value
* Cmd: ANIOC_ADS7046_READ_FASTUNSAFE Arg: uint16_t *value
* Cmd: ANIOC_ADS7046_OFFCAL Arg: N/A
*/
#define ANIOC_ADS7046_READ _ANIOC(AN_ADS7046_FIRST + 0)
#define ANIOC_ADS7046_READ_FASTUNSAFE _ANIOC(AN_ADS7046_FIRST + 1)
#define ANIOC_ADS7046_OFFCAL _ANIOC(AN_ADS7046_FIRST + 2)
/****************************************************************************
* Public Types
****************************************************************************/
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: ads7046_register
*
* Description:
* Register the ADS7046 character device as 'devpath'
*
* Input Parameters:
* devpath - The full path to the driver to register. E.g., "/dev/adc0"
* spi - An instance of the SPI interface to use.
* devno - SPI device number.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int ads7046_register(FAR const char *devpath, FAR struct spi_dev_s *spi,
unsigned int devno);
#endif /* CONFIG_ADC_ADS7046 */
#endif /* __INCLUDE_NUTTX_ANALOG_ADS7046_H */

5
include/nuttx/analog/ioctl.h
View file

@ -126,6 +126,11 @@
#define AN_MCP47X6_FIRST (AN_ADS1115_FIRST + AN_ADS1115_NCMDS)
#define AN_MCP47X6_NCMDS 3
/* See include/nuttx/analog/ads7046.h */
#define AN_ADS7046_FIRST (AN_MCP47X6_FIRST + AN_MCP47X6_NCMDS)
#define AN_ADS7046_NCMDS 3
/****************************************************************************
* Public Function Prototypes
****************************************************************************/