/****************************************************************************
* drivers/sensors/bmp180_uorb.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.
*
****************************************************************************/
/* Character driver for the Freescale BMP1801 Barometer Sensor */
/****************************************************************************
* Included Files
****************************************************************************/
#include "bmp180_base.h"
#include <nuttx/wqueue.h>
#include <nuttx/sensors/sensor.h>
#if defined(CONFIG_I2C) && defined(CONFIG_SENSORS_BMP180)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define BMP180_MIN_INTERVAL 30000
/****************************************************************************
* Private Type Definitions
****************************************************************************/
struct bmp180_dev_uorb_s
{
/* sensor_lowerhalf_s must be in the first line. */
struct sensor_lowerhalf_s lower; /* Lower half sensor driver. */
struct work_s work; /* Interrupt handler worker. */
unsigned long interval; /* Sensor acquisition interval. */
struct bmp180_dev_s dev;
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static void bmp180_worker(FAR void *arg);
static int bmp180_set_interval(FAR struct sensor_lowerhalf_s *lower,
FAR struct file *filep,
FAR unsigned long *period_us);
static int bmp180_activate(FAR struct sensor_lowerhalf_s *lower,
FAR struct file *filep,
bool enable);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct sensor_ops_s g_bmp180_ops =
{
.activate = bmp180_activate, /* Enable/disable sensor. */
.set_interval = bmp180_set_interval, /* Set output data period. */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: bmp180_set_interval
*
* Description:
* Set the sensor output data period in microseconds for a given sensor.
* If *period_us > max_delay it will be truncated to max_delay and if
* *period_us < min_delay it will be replaced by min_delay.
*
* Input Parameters:
* lower - The instance of lower half sensor driver.
* filep - The pointer of file, represents each user using the sensor.
* period_us - The time between report data, in us. It may by overwrite
* by lower half driver.
*
* Returned Value:
* Return OK(0) if the driver was success; A negated errno
* value is returned on any failure.
*
* Assumptions/Limitations:
* None.
*
****************************************************************************/
static int bmp180_set_interval(FAR struct sensor_lowerhalf_s *lower,
FAR struct file *filep,
FAR unsigned long *period_us)
{
FAR struct bmp180_dev_uorb_s *priv = (FAR struct bmp180_dev_uorb_s *)lower;
/* minimum interval 4.5ms + 25.5ms */
if (*period_us < BMP180_MIN_INTERVAL)
{
priv->interval = BMP180_MIN_INTERVAL;
*period_us = priv->interval;
}
else
{
priv->interval = *period_us;
}
return OK;
}
/****************************************************************************
* Name: bmp180_activate
*
* Description:
* Enable or disable sensor device. when enable sensor, sensor will
* work in current mode(if not set, use default mode). when disable
* sensor, it will disable sense path and stop convert.
*
* Input Parameters:
* lower - The instance of lower half sensor driver.
* filep - The pointer of file, represents each user using the sensor.
* enable - true(enable) and false(disable).
*
* Returned Value:
* Return OK(0) if the driver was success; A negated errno
* value is returned on any failure.
*
* Assumptions/Limitations:
* None.
*
****************************************************************************/
static int bmp180_activate(FAR struct sensor_lowerhalf_s *lower,
FAR struct file *filep, bool enable)
{
FAR struct bmp180_dev_uorb_s *priv = (FAR struct bmp180_dev_uorb_s *)lower;
/* Set accel output data rate. */
if (enable)
{
work_queue(HPWORK, &priv->work,
bmp180_worker, priv,
priv->interval / USEC_PER_TICK);
}
else
{
/* Set suspend mode to sensors. */
work_cancel(HPWORK, &priv->work);
}
return OK;
}
/****************************************************************************
* Name: bmp180_worker
*
* Description:
* Task the worker with retrieving the latest sensor data. We should not do
* this in a interrupt since it might take too long. Also we cannot lock
* the I2C bus from within an interrupt.
*
* Input Parameters:
* arg - Device struct.
*
* Returned Value:
* none.
*
* Assumptions/Limitations:
* none.
*
****************************************************************************/
static void bmp180_worker(FAR void *arg)
{
FAR struct bmp180_dev_uorb_s *priv = arg;
struct sensor_baro baro;
DEBUGASSERT(priv != NULL);
work_queue(HPWORK, &priv->work,
bmp180_worker, priv,
priv->interval / USEC_PER_TICK);
baro.pressure = bmp180_getpressure(&priv->dev, &baro.temperature) / 100.0f;
baro.timestamp = sensor_get_timestamp();
priv->lower.push_event(priv->lower.priv, &baro, sizeof(baro));
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: bmp180_register
*
* Description:
* Register the BMP180 character device as 'devpath'
*
* Input Parameters:
* devno - Sensor device number.
* i2c - An instance of the I2C interface to use to communicate with
* BMP180
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int bmp180_register_uorb(int devno, FAR struct i2c_master_s *i2c)
{
FAR struct bmp180_dev_uorb_s *priv;
int ret;
/* Initialize the BMP180 device structure */
priv = (FAR struct bmp180_dev_uorb_s *)
kmm_zalloc(sizeof(struct bmp180_dev_uorb_s));
if (!priv)
{
snerr("ERROR: Failed to allocate instance\n");
return -ENOMEM;
}
priv->dev.i2c = i2c;
priv->dev.addr = BMP180_ADDR;
priv->dev.freq = BMP180_FREQ;
priv->lower.ops = &g_bmp180_ops;
priv->lower.type = SENSOR_TYPE_BAROMETER;
priv->lower.nbuffer = 1;
priv->interval = BMP180_MIN_INTERVAL;
/* Check Device ID */
ret = bmp180_checkid(&priv->dev);
if (ret < 0)
{
snerr("ERROR: Failed to register driver: %d\n", ret);
kmm_free(priv);
return ret;
}
/* Read the coefficient value */
bmp180_updatecaldata(&priv->dev);
/* Register the character driver */
ret = sensor_register(&priv->lower, devno);
if (ret < 0)
{
snerr("ERROR: Failed to register driver: %d\n", ret);
kmm_free(priv);
}
sninfo("BMP180 driver loaded successfully!\n");
return ret;
}
#endif /* CONFIG_I2C && CONFIG_SENSORS_BMP180 */