416 lines
12 KiB
C
416 lines
12 KiB
C
/****************************************************************************
|
|
* drivers/sensors/mcp9844.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 <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/mcp9844.h>
|
|
#include <nuttx/random.h>
|
|
|
|
#if defined(CONFIG_I2C) && defined(CONFIG_SENSORS_MCP9844)
|
|
|
|
/****************************************************************************
|
|
* Pre-process Definitions
|
|
****************************************************************************/
|
|
|
|
#ifndef CONFIG_MCP9844_I2C_FREQUENCY
|
|
# define CONFIG_MCP9844_I2C_FREQUENCY 400000
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Private Types
|
|
****************************************************************************/
|
|
|
|
struct mcp9844_dev_s
|
|
{
|
|
FAR struct i2c_master_s *i2c; /* I2C interface */
|
|
uint8_t addr; /* I2C address */
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Private Function Prototypes
|
|
****************************************************************************/
|
|
|
|
/* I2C helper functions */
|
|
|
|
static int mcp9844_read_u16(FAR struct mcp9844_dev_s *priv,
|
|
uint8_t const regaddr, FAR uint16_t *value);
|
|
static int mcp9844_write_u16(FAR struct mcp9844_dev_s *priv,
|
|
uint8_t const regaddr, uint16_t const regval);
|
|
|
|
/* Character driver methods */
|
|
|
|
static int mcp9844_open(FAR struct file *filep);
|
|
static int mcp9844_close(FAR struct file *filep);
|
|
static ssize_t mcp9844_read(FAR struct file *filep, FAR char *buffer,
|
|
size_t buflen);
|
|
static ssize_t mcp9844_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t buflen);
|
|
static int mcp9844_ioctl(FAR struct file *filep, int cmd,
|
|
unsigned long arg);
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
static const struct file_operations g_mcp9844_fops =
|
|
{
|
|
mcp9844_open,
|
|
mcp9844_close,
|
|
mcp9844_read,
|
|
mcp9844_write,
|
|
NULL,
|
|
mcp9844_ioctl,
|
|
NULL
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: mcp9844_read_u16
|
|
*
|
|
* Description:
|
|
* Read a 16 bit valie from the MCP9844 at the address regaddr.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int mcp9844_read_u16(FAR struct mcp9844_dev_s *priv,
|
|
uint8_t const regaddr, FAR uint16_t *value)
|
|
{
|
|
struct i2c_config_s config;
|
|
uint8_t buffer[2];
|
|
int ret = -1;
|
|
|
|
/* Set up the I2C configuration */
|
|
|
|
config.frequency = CONFIG_MCP9844_I2C_FREQUENCY;
|
|
config.address = priv->addr;
|
|
config.addrlen = 7;
|
|
|
|
/* Write the register address */
|
|
|
|
ret = i2c_write(priv->i2c, &config, ®addr, 1);
|
|
if (ret < 0)
|
|
{
|
|
snerr ("i2c_write failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
/* Restart and read 16-bits from the register */
|
|
|
|
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 */
|
|
|
|
*value = (((uint16_t)(buffer[0])) << 8) + ((uint16_t)(buffer[1]));
|
|
|
|
sninfo("addr: %02x value: %08x ret: %d\n", regaddr, *value, ret);
|
|
return OK;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: mcp9844_write_u16
|
|
*
|
|
* Description:
|
|
* Write to a 16-bit register of the MCP9844.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int mcp9844_write_u16(FAR struct mcp9844_dev_s *priv,
|
|
uint8_t const regaddr, uint16_t const regval)
|
|
{
|
|
struct i2c_config_s config;
|
|
|
|
sninfo("addr: %02x value: %08x\n", regaddr, regval);
|
|
|
|
/* Set up a 3 byte message to send */
|
|
|
|
uint8_t const BUFFER_SIZE = 3;
|
|
uint8_t buffer[BUFFER_SIZE];
|
|
|
|
buffer[0] = regaddr;
|
|
buffer[1] = (uint8_t)(regval >> 8);
|
|
buffer[2] = (uint8_t)(regval);
|
|
|
|
/* Set up the I2C configuration */
|
|
|
|
config.frequency = CONFIG_MCP9844_I2C_FREQUENCY;
|
|
config.address = priv->addr;
|
|
config.addrlen = 7;
|
|
|
|
/* Write the register address followed by the data (no RESTART) */
|
|
|
|
return i2c_write(priv->i2c, &config, buffer, BUFFER_SIZE);
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: mcp9844_open
|
|
*
|
|
* Description:
|
|
* This function is called whenever the MCP9844 device is opened.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int mcp9844_open(FAR struct file *filep)
|
|
{
|
|
return OK;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: mcp9844_close
|
|
*
|
|
* Description:
|
|
* This routine is called when the MCP9844 device is closed.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int mcp9844_close(FAR struct file *filep)
|
|
{
|
|
return OK;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: mcp9844_read
|
|
****************************************************************************/
|
|
|
|
static ssize_t mcp9844_read(FAR struct file *filep, FAR char *buffer,
|
|
size_t buflen)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: mcp9844_write
|
|
****************************************************************************/
|
|
|
|
static ssize_t mcp9844_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t buflen)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: lm75_ioctl
|
|
****************************************************************************/
|
|
|
|
static int mcp9844_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
|
|
{
|
|
FAR struct inode *inode = filep->f_inode;
|
|
FAR struct mcp9844_dev_s *priv = inode->i_private;
|
|
int ret = OK;
|
|
|
|
switch (cmd)
|
|
{
|
|
/* Read from the ambient temperature register. Arg: uint16_t* pointer */
|
|
|
|
case SNIOC_READTEMP:
|
|
{
|
|
FAR struct mcp9844_temp_arg_s *temp_result =
|
|
(FAR struct mcp9844_temp_arg_s *)((uintptr_t)arg);
|
|
|
|
DEBUGASSERT(temp_result != NULL);
|
|
|
|
/* Read the ambient temperature value from the device */
|
|
|
|
uint16_t raw_temperature = 0;
|
|
ret = mcp9844_read_u16(priv, MCP9844_TEMP_REG, &raw_temperature);
|
|
|
|
/* Convert from the proprietary sensor temperature data
|
|
* representation to a more user-friendly version.
|
|
*/
|
|
|
|
if (ret == OK)
|
|
{
|
|
/* Feed sensor data to entropy pool */
|
|
|
|
add_sensor_randomness(raw_temperature);
|
|
|
|
/* BIT15 - 13 contain information if preset temperature values
|
|
* have been exceeded or undercut. BIT12 is now not any longer
|
|
* needed since we do have the sign information retrieved.
|
|
* We do not need them for the temperature so those bits
|
|
* need to be masked out.
|
|
*/
|
|
|
|
raw_temperature &= 0x0fff; /* 0x0fff = 0b 0000 1111 1111 1111 */
|
|
|
|
/* The post comma temperature value is encoded in BIT3 to
|
|
* BIT0
|
|
*/
|
|
|
|
temp_result->temp_post_comma =
|
|
(uint8_t)(raw_temperature & 0x000f);
|
|
|
|
/* The pre comma temperature value is encoded in BIT11 to
|
|
* BIT4
|
|
*/
|
|
|
|
temp_result->temp_pre_comma = (int8_t)(raw_temperature >> 4);
|
|
}
|
|
else
|
|
{
|
|
snerr("ERROR: ioctl::SNIOC_READTEMP - mcp9844_read_u16 failed"
|
|
" - no temperature retrieved\n");
|
|
}
|
|
}
|
|
break;
|
|
|
|
case SNIOC_SETRESOLUTION:
|
|
{
|
|
ret = mcp9844_write_u16(priv, MCP9844_RESO_REG, (uint16_t)(arg));
|
|
if (ret != OK)
|
|
{
|
|
snerr("ERROR: ioctl::SNIOC_SETRESOLUTION - mcp9844_write_u16"
|
|
"failed - no resolution set\n");
|
|
}
|
|
}
|
|
break;
|
|
|
|
case SNIOC_SHUTDOWN:
|
|
{
|
|
uint16_t config_reg;
|
|
|
|
/* Perform a read-modify-write cycle on the config register */
|
|
|
|
ret = mcp9844_read_u16(priv, MCP9844_CONF_REG, &config_reg);
|
|
if (ret == OK)
|
|
{
|
|
config_reg |= MCP9844_CONF_REG_SHDN;
|
|
ret = mcp9844_write_u16(priv, MCP9844_CONF_REG, config_reg);
|
|
if (ret != OK)
|
|
{
|
|
snerr("ERROR: ioctl::SNIOC_SHUTDOWN - "
|
|
"mcp9844_write_u16 failed\n");
|
|
}
|
|
}
|
|
else
|
|
{
|
|
snerr("ERROR: ioctl::SNIOC_SHUTDOWN - "
|
|
"mcp9844_read_u16 failed\n");
|
|
}
|
|
}
|
|
break;
|
|
|
|
case SNIOC_POWERUP:
|
|
{
|
|
uint16_t config_reg;
|
|
|
|
/* Perform a read-modify-write cycle on the config register */
|
|
|
|
ret = mcp9844_read_u16(priv, MCP9844_CONF_REG, &config_reg);
|
|
if (ret == OK)
|
|
{
|
|
config_reg &= ~MCP9844_CONF_REG_SHDN;
|
|
ret = mcp9844_write_u16(priv, MCP9844_CONF_REG, config_reg);
|
|
if (ret != OK)
|
|
{
|
|
snerr("ERROR: ioctl::SNIOC_POWERUP - "
|
|
"mcp9844_write_u16 failed\n");
|
|
}
|
|
}
|
|
else
|
|
{
|
|
snerr("ERROR: ioctl::SNIOC_POWERUP - "
|
|
"mcp9844_read_u16 failed\n");
|
|
}
|
|
}
|
|
break;
|
|
|
|
default:
|
|
snerr("ERROR: Unrecognized cmd: %d\n", cmd);
|
|
ret = -ENOTTY;
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: mcp9844_register
|
|
*
|
|
* Description:
|
|
* Register the MCP9844 character device as 'devpath'
|
|
*
|
|
* Input Parameters:
|
|
* devpath - The full path to the driver to register. E.g., "/dev/temp0"
|
|
* i2c - An instance of the I2C interface to use to communicate with
|
|
* MCP9844
|
|
* addr - The I2C address of the MCP9844.
|
|
*
|
|
* Returned Value:
|
|
* Zero (OK) on success; a negated errno value on failure.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int mcp9844_register(FAR const char *devpath, FAR struct i2c_master_s *i2c,
|
|
uint8_t addr)
|
|
{
|
|
/* Sanity check */
|
|
|
|
DEBUGASSERT(i2c != NULL);
|
|
|
|
/* Initialize the MCP9844 device structure */
|
|
|
|
FAR struct mcp9844_dev_s *priv =
|
|
(FAR struct mcp9844_dev_s *)kmm_malloc(sizeof(struct mcp9844_dev_s));
|
|
|
|
if (priv == NULL)
|
|
{
|
|
snerr("ERROR: Failed to allocate instance\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
priv->i2c = i2c;
|
|
priv->addr = addr;
|
|
|
|
/* Register the character driver */
|
|
|
|
int ret = register_driver(devpath, &g_mcp9844_fops, 0666, priv);
|
|
if (ret < 0)
|
|
{
|
|
snerr("ERROR: Failed to register driver: %d\n", ret);
|
|
kmm_free(priv);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
#endif /* CONFIG_I2C && CONFIG_LM75_I2C */
|