/**************************************************************************** * 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 #include #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 */