414 lines
13 KiB
C
414 lines
13 KiB
C
/****************************************************************************
|
|
* drivers/sensors/ina219.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 <inttypes.h>
|
|
#include <stdlib.h>
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <debug.h>
|
|
|
|
#include <nuttx/kmalloc.h>
|
|
#include <nuttx/fs/fs.h>
|
|
#include <nuttx/i2c/i2c_master.h>
|
|
#include <nuttx/sensors/ina219.h>
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#if !defined(CONFIG_I2C)
|
|
# error i2c support required
|
|
#endif
|
|
|
|
#define INA219_REG_CONFIG 0 /* See below */
|
|
#define INA219_REG_SHUNT_VOLTAGE 1 /* Shunt voltage in 10 uV units */
|
|
#define INA219_REG_BUS_VOLTAGE 2 /* Bus votlage in 4 mV units */
|
|
#define INA219_REG_POWER 3 /* Requires prior calibration */
|
|
#define INA219_REG_CURRENT 4 /* Requires prior calibration */
|
|
#define INA219_REG_CALIBRATION 5 /* Calibration value to compute current */
|
|
|
|
/* Operating modes - not controllable by user */
|
|
|
|
#define INA219_CONFIG_OPMODE_SHIFT 0
|
|
#define INA219_CONFIG_OPMODE_MASK (7 << INA219_CONFIG_OPMODE_SHIFT)
|
|
#define INA219_CONFIG_OPMODE_PWRDOWN (0 << INA219_CONFIG_OPMODE_SHIFT)
|
|
#define INA219_CONFIG_OPMODE_STRIG (1 << INA219_CONFIG_OPMODE_SHIFT)
|
|
#define INA219_CONFIG_OPMODE_BTRIG (2 << INA219_CONFIG_OPMODE_SHIFT)
|
|
#define INA219_CONFIG_OPMODE_SBTRIG (3 << INA219_CONFIG_OPMODE_SHIFT)
|
|
#define INA219_CONFIG_OPMODE_OFF (4 << INA219_CONFIG_OPMODE_SHIFT)
|
|
#define INA219_CONFIG_OPMODE_SCONT (5 << INA219_CONFIG_OPMODE_SHIFT)
|
|
#define INA219_CONFIG_OPMODE_BCONT (6 << INA219_CONFIG_OPMODE_SHIFT)
|
|
#define INA219_CONFIG_OPMODE_SBCONT (7 << INA219_CONFIG_OPMODE_SHIFT)
|
|
|
|
#ifndef CONFIG_INA219_I2C_FREQUENCY
|
|
# define CONFIG_INA219_I2C_FREQUENCY 400000
|
|
#endif
|
|
|
|
#define I2C_NOSTARTSTOP_MSGS 2
|
|
#define I2C_NOSTARTSTOP_ADDRESS_MSG_INDEX 0
|
|
#define I2C_NOSTARTSTOP_DATA_MSG_INDEX 1
|
|
|
|
/****************************************************************************
|
|
* Private Types
|
|
****************************************************************************/
|
|
|
|
struct ina219_dev_s
|
|
{
|
|
FAR struct i2c_master_s *i2c; /* I2C interface */
|
|
uint8_t addr; /* I2C address */
|
|
uint16_t config; /* INA 219 config shadow */
|
|
int32_t shunt_resistor_value; /* micro-ohms, max 2.15 kohms */
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Private Function Prototypes
|
|
****************************************************************************/
|
|
|
|
/* I2C Helpers */
|
|
|
|
static int ina219_write16(FAR struct ina219_dev_s *priv, uint8_t regaddr,
|
|
FAR uint16_t regvalue);
|
|
static int ina219_read16(FAR struct ina219_dev_s *priv, uint8_t regaddr,
|
|
FAR uint16_t *regvalue);
|
|
static int ina219_readpower(FAR struct ina219_dev_s *priv,
|
|
FAR struct ina219_s *buffer);
|
|
|
|
/* Character driver methods */
|
|
|
|
static int ina219_open(FAR struct file *filep);
|
|
static int ina219_close(FAR struct file *filep);
|
|
static ssize_t ina219_read(FAR struct file *filep, FAR char *buffer,
|
|
size_t buflen);
|
|
static ssize_t ina219_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t buflen);
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
static const struct file_operations g_ina219fops =
|
|
{
|
|
ina219_open, /* open */
|
|
ina219_close, /* close */
|
|
ina219_read, /* read */
|
|
ina219_write, /* write */
|
|
NULL, /* seek */
|
|
NULL, /* ioctl */
|
|
NULL /* poll */
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
, NULL /* unlink */
|
|
#endif
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
static int ina219_access(FAR struct ina219_dev_s *priv,
|
|
uint8_t start_register_address, bool reading,
|
|
FAR uint8_t *register_value, uint8_t data_length)
|
|
{
|
|
struct i2c_msg_s msg[I2C_NOSTARTSTOP_MSGS];
|
|
int ret;
|
|
|
|
msg[I2C_NOSTARTSTOP_ADDRESS_MSG_INDEX].frequency =
|
|
CONFIG_INA219_I2C_FREQUENCY;
|
|
|
|
msg[I2C_NOSTARTSTOP_ADDRESS_MSG_INDEX].addr = priv->addr;
|
|
msg[I2C_NOSTARTSTOP_ADDRESS_MSG_INDEX].flags = 0;
|
|
msg[I2C_NOSTARTSTOP_ADDRESS_MSG_INDEX].buffer = &start_register_address;
|
|
msg[I2C_NOSTARTSTOP_ADDRESS_MSG_INDEX].length = 1;
|
|
|
|
msg[I2C_NOSTARTSTOP_DATA_MSG_INDEX].addr =
|
|
msg[I2C_NOSTARTSTOP_ADDRESS_MSG_INDEX].addr;
|
|
msg[I2C_NOSTARTSTOP_DATA_MSG_INDEX].flags = reading ? I2C_M_READ : 0;
|
|
msg[I2C_NOSTARTSTOP_DATA_MSG_INDEX].buffer = register_value;
|
|
msg[I2C_NOSTARTSTOP_DATA_MSG_INDEX].length = data_length;
|
|
|
|
ret = I2C_TRANSFER(priv->i2c, msg, I2C_NOSTARTSTOP_MSGS);
|
|
|
|
sninfo("start_register_address: "
|
|
"0x%02X data_length: %d register_value: 0x%02x (0x%04x) ret: %d\n",
|
|
start_register_address, data_length, *register_value,
|
|
*((FAR uint16_t *)register_value), ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int ina219_read16(FAR struct ina219_dev_s *priv, uint8_t regaddr,
|
|
FAR uint16_t *regvalue)
|
|
{
|
|
uint8_t buf[2];
|
|
|
|
int ret = ina219_access(priv, regaddr, true, buf, 2);
|
|
|
|
if (ret == 0)
|
|
{
|
|
*regvalue = ((uint16_t)buf[0] << 8) | (uint16_t)buf[1];
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int ina219_write16(FAR struct ina219_dev_s *priv, uint8_t regaddr,
|
|
FAR uint16_t regvalue)
|
|
{
|
|
uint8_t buf[2];
|
|
|
|
int ret;
|
|
|
|
buf[0] = (regvalue >> 8) & 0xff;
|
|
buf[1] = regvalue & 0xff;
|
|
|
|
ret = ina219_access(priv, regaddr, false, buf, 2);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: ina219_readpower
|
|
*
|
|
* Description:
|
|
* Read the current and voltage register with special scaling
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int ina219_readpower(FAR struct ina219_dev_s *priv,
|
|
FAR struct ina219_s *buffer)
|
|
{
|
|
uint16_t reg;
|
|
int64_t tmp;
|
|
|
|
int ret;
|
|
|
|
/* Read the raw bus voltage */
|
|
|
|
ret = ina219_read16(priv, INA219_REG_BUS_VOLTAGE, ®);
|
|
if (ret < 0)
|
|
{
|
|
snerr("ERROR: ina219_read16 failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
/* Convert register value to bus voltage */
|
|
|
|
reg >>= 3; /* 3 LSB of reg contains status bits */
|
|
buffer->voltage = ((uint32_t)reg) * 4000LU;
|
|
|
|
/* Read the raw shunt voltage */
|
|
|
|
ret = ina219_read16(priv, INA219_REG_SHUNT_VOLTAGE, ®);
|
|
if (ret < 0)
|
|
{
|
|
snerr("ERROR: ina219_read16 failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
/* Convert register value to shunt voltage */
|
|
|
|
tmp = ((int64_t)(int16_t)reg) * 10LL; /* micro volts across shunt */
|
|
|
|
/* Convert shunt voltage to current across the shunt resistor.
|
|
* I(uA) = U(uV)/R(ohms)
|
|
* = U(uV)/(R(uohms)/1000000)
|
|
* = U(uV) * 1000000 / R(uohms)
|
|
* We use a temporary 64-bit accumulator to avoid overflows.
|
|
*/
|
|
|
|
tmp = tmp * 1000000LL;
|
|
tmp = tmp / (int64_t)priv->shunt_resistor_value;
|
|
|
|
buffer->current = (int32_t)tmp;
|
|
|
|
sninfo("Voltage: %" PRIu32 " uV, Current: %" PRId32 " uA\n",
|
|
buffer->voltage, buffer->current);
|
|
|
|
return OK;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: ina219_open
|
|
*
|
|
* Description:
|
|
* This function is called whenever the INA219 device is opened.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int ina219_open(FAR struct file *filep)
|
|
{
|
|
FAR struct inode *inode = filep->f_inode;
|
|
FAR struct ina219_dev_s *priv = inode->i_private;
|
|
|
|
return ina219_write16(priv, INA219_REG_CONFIG,
|
|
priv->config | INA219_CONFIG_OPMODE_SBCONT);
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: ina219_close
|
|
*
|
|
* Description:
|
|
* This routine is called when the INA219 device is closed.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int ina219_close(FAR struct file *filep)
|
|
{
|
|
FAR struct inode *inode = filep->f_inode;
|
|
FAR struct ina219_dev_s *priv = inode->i_private;
|
|
|
|
return ina219_write16(priv, INA219_REG_CONFIG,
|
|
priv->config | INA219_CONFIG_OPMODE_OFF);
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: ina219_read
|
|
****************************************************************************/
|
|
|
|
static ssize_t ina219_read(FAR struct file *filep, FAR char *buffer,
|
|
size_t buflen)
|
|
{
|
|
FAR struct inode *inode = filep->f_inode;
|
|
FAR struct ina219_dev_s *priv = inode->i_private;
|
|
FAR struct ina219_s *ptr;
|
|
ssize_t nsamples;
|
|
int i;
|
|
int ret;
|
|
|
|
/* How many samples were requested to get? */
|
|
|
|
nsamples = buflen / sizeof(struct ina219_s);
|
|
ptr = (FAR struct ina219_s *)buffer;
|
|
|
|
sninfo("buflen: %d nsamples: %d\n", buflen, nsamples);
|
|
|
|
/* Get the requested number of samples */
|
|
|
|
for (i = 0; i < nsamples; i++)
|
|
{
|
|
struct ina219_s pwr;
|
|
|
|
/* Read the next struct ina219_s power value */
|
|
|
|
ret = ina219_readpower(priv, &pwr);
|
|
if (ret < 0)
|
|
{
|
|
snerr("ERROR: ina219_readpower failed: %d\n", ret);
|
|
return (ssize_t)ret;
|
|
}
|
|
|
|
/* Save the temperature value in the user buffer */
|
|
|
|
*ptr++ = pwr;
|
|
}
|
|
|
|
return nsamples * sizeof(struct ina219_s);
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: ina219_write
|
|
****************************************************************************/
|
|
|
|
static ssize_t ina219_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t buflen)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: ina219_register
|
|
*
|
|
* Description:
|
|
* Register the INA219 character device as 'devpath'
|
|
*
|
|
* Input Parameters:
|
|
* devpath - The full path to the driver to register. E.g., "/dev/pwrmntr0"
|
|
* i2c - An instance of the I2C interface to use to communicate with INA219
|
|
* addr - The I2C address of the INA219.
|
|
* shuntval - the shunt resistor value in micro-ohms.
|
|
*
|
|
* Returned Value:
|
|
* Zero (OK) on success; a negated errno value on failure.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int ina219_register(FAR const char *devpath, FAR struct i2c_master_s *i2c,
|
|
uint8_t addr, int32_t shuntval, uint16_t config)
|
|
{
|
|
FAR struct ina219_dev_s *priv;
|
|
int ret = 0;
|
|
|
|
/* Sanity check */
|
|
|
|
DEBUGASSERT(i2c != NULL);
|
|
|
|
/* Initialize the ina219 device structure */
|
|
|
|
priv = (FAR struct ina219_dev_s *)kmm_malloc(sizeof(struct ina219_dev_s));
|
|
if (priv == NULL)
|
|
{
|
|
snerr("ERROR: Failed to allocate instance\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
priv->i2c = i2c;
|
|
priv->addr = addr;
|
|
priv->shunt_resistor_value = shuntval;
|
|
|
|
/* Save the config (except opmode) */
|
|
|
|
priv->config = config & ~INA219_CONFIG_OPMODE_MASK;
|
|
|
|
/* Apply config, keep chip switched off */
|
|
|
|
ret = ina219_write16(priv, INA219_REG_CONFIG,
|
|
priv->config | INA219_CONFIG_OPMODE_OFF);
|
|
if (ret < 0)
|
|
{
|
|
snerr("ERROR: Failed to apply config: %d\n", ret);
|
|
goto errout;
|
|
}
|
|
|
|
/* Register the character driver */
|
|
|
|
ret = register_driver(devpath, &g_ina219fops, 0666, priv);
|
|
if (ret < 0)
|
|
{
|
|
snerr("ERROR: Failed to register driver: %d\n", ret);
|
|
goto errout;
|
|
}
|
|
|
|
sninfo("(addr=0x%02x) registered at %s\n", priv->addr, devpath);
|
|
return ret;
|
|
|
|
errout:
|
|
kmm_free(priv);
|
|
return ret;
|
|
}
|