992 lines
27 KiB
C
992 lines
27 KiB
C
/****************************************************************************
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* drivers/sensors/ds18b20_uorb.c
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* Character driver for DS18B20 Digital Humidity and Temperature Module.
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <assert.h>
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#include <errno.h>
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#include <debug.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdbool.h>
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#include <nuttx/kmalloc.h>
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#include <nuttx/kthread.h>
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#include <nuttx/signal.h>
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#include <nuttx/semaphore.h>
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#include <nuttx/fs/fs.h>
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#include <nuttx/1wire/1wire.h>
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#include <nuttx/1wire/1wire_master.h>
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#include <nuttx/1wire/1wire_crc.h>
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#include <nuttx/sensors/ds18b20.h>
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#include <nuttx/sensors/sensor.h>
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#if defined(CONFIG_1WIRE) && defined(CONFIG_SENSORS_DS18B20)
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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#ifndef CONFIG_ENDIAN_BIG
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# define ds18b20_leuint64(x) (x)
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#endif
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/* Scratchpad data definition for reading */
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#define DS18B20_SPAD_LSB_OFFSET 0
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#define DS18B20_SPAD_MSB_OFFSET 1
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#define DS18B20_SPAD_TH_OFFSET 2
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#define DS18B20_SPAD_TL_OFFSET 3
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#define DS18B20_SPAD_RES_OFFSET 4
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#define DS18B20_SPAD_CRC_OFFSET 9
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#define DS18B20_SPAD_SIZE 9
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/* Scratchpad data definition for writing */
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#define DS18B20_WSPAD_CMD_OFFSET 0
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#define DS18B20_WSPAD_TH_OFFSET 0
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#define DS18B20_WSPAD_TL_OFFSET 1
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#define DS18B20_WSPAD_RES_OFFSET 2
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#define DS18B20_WSPAD_SIZE 3
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/* Measurement resolution bit definition */
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#define DS18B20_RESMIN 0
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#define DS18B20_RESMAX 3
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#define DS18B20_NRES DS18B20_RESMAX - DS18B20_RESMIN + 1
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#define DS18B20_RES_VAL(x) (((x) >> 5) & 0x3)
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#define DS18B20_RES_CONV(x) (((x) & 0x3) << 5)
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/* Measurement timneout offset */
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#define DS18B20_TIMEOUT_OFFSET(x) (DS18B20_RESMAX - (x))
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/* Default alarm temperature */
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#define DS18B20_TALARM_MIN -55
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#define DS18B20_TALARM_MAX 125
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/* Helper for getting data from scratchpad memory */
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#define DS18B20_TEMP_PREDEC(lsb, msb) (int8_t)(((msb) << 4) | ((lsb) >> 4))
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#define DS18B20_TEMP_RES(lsb, res) (DS18B20_RESMAX - DS18B20_RES_VAL(res))
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#define DS18B20_TEMP_RESMASK(lsb, res) (0x0f << DS18B20_TEMP_RES(lsb, res))
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#define DS18B20_TEMP_DEC(lsb, res) (((lsb) & 0x0f) & \
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DS18B20_TEMP_RESMASK(lsb, res))
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#define DS18B20_TEMP(lsb, msb, res) (DS18B20_TEMP_PREDEC(lsb, msb) + \
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DS18B20_TEMP_DEC(lsb, res) / 16.0)
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/****************************************************************************
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* Private Types
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****************************************************************************/
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/* Internal sensor data */
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struct ds18b20_sensor_data_s
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{
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uint64_t timestamp;
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uint8_t spad[DS18B20_SPAD_SIZE];
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};
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/* User configuration register */
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struct ds18b20_config_s
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{
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uint8_t res; /* Sensor resolution */
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struct ds18b20_alarm_s alarm; /* Sensor temperature alarm */
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};
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/* Callback handling for alarm detection */
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struct ds18b20_cb_alarm_s
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{
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bool isalarm;
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uint64_t romcode;
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};
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/* Lower sensor */
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struct ds18b20_sensor_s
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{
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struct sensor_lowerhalf_s lower; /* Common lower interface */
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#ifdef CONFIG_SENSORS_DS18B20_POLL
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bool enabled; /* Sensor activated */
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#endif
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};
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/* Internal device */
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struct ds18b20_dev_s
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{
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struct ds18b20_sensor_s sensor; /* Sensor */
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FAR struct onewire_master_s *master; /* 1wire master interface */
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struct onewire_config_s config; /* 1wire device configuration */
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struct ds18b20_config_s reg; /* Sensor resolution */
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#ifdef CONFIG_SENSORS_DS18B20_POLL
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uint32_t interval; /* Polling interval */
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sem_t run; /* Locks sensor thread */
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#endif
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};
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/****************************************************************************
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* Private Function Prototypes
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****************************************************************************/
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/* Sensor functions */
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static int ds18b20_active(FAR struct sensor_lowerhalf_s *lower,
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FAR struct file *filep,
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bool enabled);
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static int ds18b20_fetch(FAR struct sensor_lowerhalf_s *lower,
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FAR struct file *filep,
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FAR char *buffer, size_t buflen);
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static int ds18b20_control(FAR struct sensor_lowerhalf_s *lower,
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FAR struct file *filep,
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int cmd, unsigned long arg);
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#ifdef CONFIG_SENSORS_DS18B20_POLL
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static int ds18b20_set_interval(FAR struct sensor_lowerhalf_s *lower,
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FAR struct file *filep,
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FAR uint32_t *period_us);
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#endif
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/****************************************************************************
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* Private Data
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****************************************************************************/
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/* Timeout definitions after measurement according to the data sheet */
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static const uint32_t g_res_timeout[DS18B20_NRES] =
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{
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93750,
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187500,
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375000,
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750000
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};
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static const struct sensor_ops_s g_ds18b20_ops =
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{
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#ifdef CONFIG_SENSORS_DS18B20_POLL
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.set_interval = ds18b20_set_interval,
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#endif
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.activate = ds18b20_active,
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.fetch = ds18b20_fetch,
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.control = ds18b20_control
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};
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: ds18b20_rawdata
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*
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* Description:
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* Helper for extract temperature data from scratchpad
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*
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* Return:
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* Raw temperature data
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*
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****************************************************************************/
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static inline int16_t ds18b20_rawtemp(FAR const uint8_t *spad)
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{
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return (spad[DS18B20_SPAD_LSB_OFFSET] |
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(spad[DS18B20_SPAD_MSB_OFFSET] << 8));
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}
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/****************************************************************************
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* Name: ds18b20_tempdata
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*
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* Description:
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* Helper for converting temperature data from raw sensor data
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*
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* Return:
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* Temperature data
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*
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****************************************************************************/
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static inline float ds18b20_temp(FAR const uint8_t *spad)
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{
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int8_t predec = DS18B20_TEMP_PREDEC(spad[DS18B20_SPAD_LSB_OFFSET],
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spad[DS18B20_SPAD_MSB_OFFSET]);
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uint8_t dec = DS18B20_TEMP_DEC(spad[DS18B20_SPAD_LSB_OFFSET],
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spad[DS18B20_SPAD_RES_OFFSET]);
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return predec + dec / 16.0;
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}
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/****************************************************************************
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* Name: ds18b20_alarm_cb
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*
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* Description:
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* Call back function for searching a single alarm device.
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*
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* Input Parameters:
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* romcode - Unique romcode of a device with alarm flag set
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* arg - Pointer to struct onewire_alarm_s
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*
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****************************************************************************/
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#ifdef CONFIG_SENSORS_DS18B20_POLL
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static void ds18b20_alarm_cb(int family, uint64_t romcode, FAR void *arg)
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{
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FAR struct ds18b20_cb_alarm_s *priv = (FAR struct ds18b20_cb_alarm_s *)arg;
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if (romcode == priv->romcode)
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{
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priv->isalarm = true;
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}
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}
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#endif
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/****************************************************************************
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* Name: ds18b20_isalarm
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*
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* Description:
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* Check if a 1wire device has set the alarm flag in an atomic operation.
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*
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* Input Parameters:
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* master - Pointer to the allocated 1-wire interface
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* config - Described the 1WIRE configuration
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*
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* Return Value:
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* 0 - no alarm flag is set
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* 1 - alarm flag is set
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* < 0 - in case of error
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*
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****************************************************************************/
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#ifdef CONFIG_SENSORS_DS18B20_POLL
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static int ds18b20_isalarm(FAR struct onewire_master_s *master,
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FAR const struct onewire_config_s *config)
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{
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int ret;
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struct ds18b20_cb_alarm_s alarm;
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alarm.romcode = config->romcode;
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alarm.isalarm = false;
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ret = onewire_search(master, DS18B20_DEVICE_FAMILY, true, ds18b20_alarm_cb,
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&alarm);
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if (ret > 0)
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{
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/* Check if our device is in the alarm list */
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if (alarm.isalarm == true)
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{
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ret = 1;
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}
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else
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{
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/* Device found, but not our */
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ret = 0;
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}
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}
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return ret;
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}
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#endif
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/****************************************************************************
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* Name: ds18b20_measure
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*
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* Description: Perform a measurement
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*
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* Parameter:
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* dev - Internal private lower half driver instance
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*
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* Return:
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* OK - on success
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****************************************************************************/
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static int ds18b20_measure(FAR struct ds18b20_dev_s *dev)
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{
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int ret;
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uint8_t buf = DS18B20_CMD_CONVERTT;
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ret = onewire_write(dev->master, &dev->config, &buf, 1);
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if (ret < 0)
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{
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snerr("ERROR: Unable to perform a temperature measurement\n");
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return ret;
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}
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return OK;
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}
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/****************************************************************************
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* Name: ds18b20_write_spad
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*
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* Description: Write scratchpad data to chip
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*
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* Parameter:
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* dev - Internal private lower half driver instance
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* th - High alarm temperature
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* lh - Low alarm temperature
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* res - Temperature resolution
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*
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* Return:
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* OK - on success
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****************************************************************************/
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static int ds18b20_write_spad(FAR struct ds18b20_dev_s *dev, int8_t th,
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int8_t tl, uint8_t res)
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{
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int ret;
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uint8_t wbuf[DS18B20_WSPAD_SIZE + 1];
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wbuf[DS18B20_WSPAD_CMD_OFFSET] = ONEWIRE_CMD_WRITE_SCRATCHPAD;
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wbuf[DS18B20_WSPAD_TH_OFFSET + 1] = th;
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wbuf[DS18B20_WSPAD_TL_OFFSET + 1] = tl;
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wbuf[DS18B20_WSPAD_RES_OFFSET + 1] = res;
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ret = onewire_write(dev->master, &dev->config, wbuf, sizeof(wbuf));
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if (ret < 0)
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{
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snerr("ERROR: Unable to write scratchpad\n");
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}
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return ret;
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}
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/****************************************************************************
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* Name: ds18b20_read_spad
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*
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* Description: Read scratchpad data from chip
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*
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* Parameter:
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* dev - Internal private lower half driver instance
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* spad - Pointer to store the scratchpad data
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*
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* Return:
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* OK - on success
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****************************************************************************/
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static int ds18b20_read_spad(FAR struct ds18b20_dev_s *dev,
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FAR uint8_t *spad)
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{
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int ret;
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uint8_t crc;
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uint8_t wbuf = ONEWIRE_CMD_READ_SCRATCHPAD;
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FAR struct ds18b20_config_s *reg = &dev->reg;
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ret = onewire_writeread(dev->master, &dev->config, &wbuf, 1, spad,
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DS18B20_SPAD_SIZE);
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if (ret < 0)
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{
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snerr("ERROR: Unable to read scratchpad\n");
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return ret;
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}
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crc = onewire_crc8(spad, DS18B20_SPAD_SIZE - 1);
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if (crc != spad[DS18B20_SPAD_CRC_OFFSET - 1])
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{
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snerr("ERROR: crc mismatch in scratchpad\n");
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return -EIO;
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}
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/* Update configurable register state each time reading the scratchpad */
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reg->res = spad[DS18B20_SPAD_RES_OFFSET];
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if (reg->res < DS18B20_RES_CONV(DS18B20_RESMIN) ||
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reg->res > DS18B20_RES_CONV(reg->res))
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{
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/* Usually this should not happen, but be sure that we did not run into
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* a buffer overflow later.
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*/
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swarn("WARNING: Sensor responded unknown resolution: %d\n", reg->res);
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reg->res = DS18B20_RES_CONV(DS18B20_RESMAX);
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}
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reg->alarm.thigh = spad[DS18B20_SPAD_TH_OFFSET];
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reg->alarm.tlow = spad[DS18B20_SPAD_TL_OFFSET];
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return OK;
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}
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/****************************************************************************
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* Name: ds18b20_set_res
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*
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* Description: Set resolution for temperature measurement
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*
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* Parameter:
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* dev - Internal private lower half driver instance
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* res - Resolution, can be 9 to 12 bit
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*
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* Return:
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* OK - on success
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****************************************************************************/
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static int ds18b20_set_res(FAR struct ds18b20_dev_s *dev, uint8_t res)
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{
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int ret;
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uint8_t spad[DS18B20_SPAD_SIZE];
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/* Read current scratchpad first */
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ret = ds18b20_read_spad(dev, spad);
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if (ret < 0)
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{
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return ret;
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}
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ret = ds18b20_write_spad(dev, dev->reg.alarm.thigh, dev->reg.alarm.tlow,
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res);
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if (ret < 0)
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{
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return ret;
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}
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/* Read current scratchpad again and verify that res is set */
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ret = ds18b20_read_spad(dev, spad);
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if (ret < 0)
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{
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return ret;
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}
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if (DS18B20_RES_VAL(spad[DS18B20_SPAD_RES_OFFSET]) != DS18B20_RES_VAL(res))
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{
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snerr("ERROR: Expected resolution not matched, received RES: %d\n",
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spad[DS18B20_SPAD_RES_OFFSET]);
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return -EIO;
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}
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return OK;
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}
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/****************************************************************************
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* Name: ds18b20_set_alarm
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*
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* Description: Set temperature alarm
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*
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* Parameter:
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* dev - Internal private lower half driver instance
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* alarm - Pointer to store the alarm temperature
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*
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* Return:
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* OK - on success
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****************************************************************************/
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static int ds18b20_set_alarm(FAR struct ds18b20_dev_s *dev,
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FAR const struct ds18b20_alarm_s *alarm)
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{
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int ret;
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uint8_t spad[DS18B20_SPAD_SIZE];
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/* Read current scratchpad first, to get current resolution */
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ret = ds18b20_read_spad(dev, spad);
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if (ret < 0)
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{
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return ret;
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}
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ret = ds18b20_write_spad(dev, alarm->thigh, alarm->tlow, dev->reg.res);
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if (ret < 0)
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{
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return ret;
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}
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#ifdef CONFIG_SENSORS_DS18B20_POLL
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dev->reg.alarm.wakeup = alarm->wakeup;
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#endif
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/* Read current scratchpad again and verify that alarm is set */
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ret = ds18b20_read_spad(dev, spad);
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if (ret < 0)
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{
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return ret;
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}
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if (spad[DS18B20_SPAD_TH_OFFSET] != alarm->thigh ||
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spad[DS18B20_SPAD_TL_OFFSET] != alarm->tlow)
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{
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snerr("ERROR: Expected alarm trigger does not match, "
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"received TH: %d, TL: %d\n",
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spad[DS18B20_SPAD_TH_OFFSET],
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spad[DS18B20_SPAD_TL_OFFSET]);
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return -EIO;
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}
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return ret;
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}
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/****************************************************************************
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* Name: ds18b20_curtime
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*
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* Description: Helper to get current timestamp.
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*
|
|
* Return:
|
|
* Timestamp in nsec
|
|
****************************************************************************/
|
|
|
|
static unsigned long ds18b20_curtime(void)
|
|
{
|
|
struct timespec ts;
|
|
|
|
clock_systime_timespec(&ts);
|
|
return 1000000ull * ts.tv_sec + ts.tv_nsec / 1000;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: ds18b20_notify
|
|
*
|
|
* Description:
|
|
* Notify upper about data has been changed.
|
|
*
|
|
* Parameter:
|
|
* dev - Internal private lower half driver instance
|
|
* data - Read sensor data
|
|
*
|
|
****************************************************************************/
|
|
|
|
#ifdef CONFIG_SENSORS_DS18B20_POLL
|
|
static void ds18b20_notify(FAR struct ds18b20_dev_s *dev,
|
|
FAR struct ds18b20_sensor_data_s *data)
|
|
{
|
|
FAR struct ds18b20_sensor_s *sensor = &dev->sensor;
|
|
struct sensor_temp temp;
|
|
|
|
temp.temperature = ds18b20_temp(data->spad);
|
|
temp.timestamp = data->timestamp;
|
|
sensor->lower.push_event(sensor->lower.priv, &temp,
|
|
sizeof(struct sensor_temp));
|
|
}
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Name: ds18b20_measure_read
|
|
*
|
|
* Description: Perform a measurement and read last measured temperature
|
|
*
|
|
* Parameter:
|
|
* dev - Internal private lower half driver instance
|
|
* data - Pointer to store sensor data
|
|
*
|
|
* Return:
|
|
* OK - on success
|
|
****************************************************************************/
|
|
|
|
static int ds18b20_measure_read(FAR struct ds18b20_dev_s *dev,
|
|
FAR struct ds18b20_sensor_data_s *data)
|
|
{
|
|
int ret;
|
|
|
|
ret = ds18b20_measure(dev);
|
|
if (ret < 0)
|
|
{
|
|
return ret;
|
|
}
|
|
|
|
nxsig_usleep(g_res_timeout[DS18B20_RES_VAL(dev->reg.res)]);
|
|
|
|
ret = ds18b20_read_spad(dev, data->spad);
|
|
if (ret < 0)
|
|
{
|
|
return ret;
|
|
}
|
|
|
|
data->timestamp = ds18b20_curtime();
|
|
return OK;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: ds18b20_fetch
|
|
*
|
|
* Description: Performs a measuremnt cylce and data read with data
|
|
* conversion.
|
|
*
|
|
* Parameter:
|
|
* lower - Pointer to lower half sensor driver instance.
|
|
* filep - The pointer of file, represents each user using the sensor.
|
|
* buffer - Pointer to the buffer for reading data.
|
|
* buflen - Size of the buffer.
|
|
*
|
|
* Return:
|
|
* OK - on success
|
|
****************************************************************************/
|
|
|
|
static int ds18b20_fetch(FAR struct sensor_lowerhalf_s *lower,
|
|
FAR struct file *filep,
|
|
FAR char *buffer, size_t buflen)
|
|
{
|
|
int ret;
|
|
struct ds18b20_sensor_data_s data;
|
|
FAR struct ds18b20_dev_s *priv = (FAR struct ds18b20_dev_s *)lower;
|
|
|
|
/* Check if the user is reading the right size */
|
|
|
|
if (buflen != sizeof(struct sensor_temp))
|
|
{
|
|
snerr("ERROR: You need to read %d bytes from this sensor!\n",
|
|
sizeof(struct sensor_temp));
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = ds18b20_measure_read(priv, &data);
|
|
if (!ret)
|
|
{
|
|
FAR struct sensor_temp *temp =
|
|
(FAR struct sensor_temp *)buffer;
|
|
temp->temperature = ds18b20_temp(data.spad);
|
|
temp->timestamp = data.timestamp;
|
|
}
|
|
else
|
|
{
|
|
return ret;
|
|
}
|
|
|
|
return buflen;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: ds18b20_control
|
|
*
|
|
* Description: Interface function of struct sensor_ops_s.
|
|
*
|
|
* Return:
|
|
* OK - on success
|
|
****************************************************************************/
|
|
|
|
static int ds18b20_control(FAR struct sensor_lowerhalf_s *lower,
|
|
FAR struct file *filep,
|
|
int cmd, unsigned long arg)
|
|
{
|
|
int ret;
|
|
struct ds18b20_dev_s *priv = (FAR struct ds18b20_dev_s *)lower;
|
|
|
|
switch (cmd)
|
|
{
|
|
/* Read rom code */
|
|
|
|
case SNIOC_READROMCODE:
|
|
{
|
|
FAR uint64_t *ptr = (FAR uint64_t *)((uintptr_t)arg);
|
|
DEBUGASSERT(ptr != NULL);
|
|
*ptr = priv->config.romcode;
|
|
sninfo("read romcode: %16llx\n", *ptr);
|
|
ret = OK;
|
|
}
|
|
break;
|
|
|
|
/* Set new temperature alarm */
|
|
|
|
case SNIOC_SETALARM:
|
|
{
|
|
FAR struct ds18b20_alarm_s *ptr =
|
|
(FAR struct ds18b20_alarm_s *)((uintptr_t)arg);
|
|
DEBUGASSERT(ptr != NULL);
|
|
sninfo("set alarm: [TH/TL] = %d/%d °C\n", ptr->thigh, ptr->tlow);
|
|
ret = ds18b20_set_alarm(priv, ptr);
|
|
}
|
|
break;
|
|
|
|
/* Set sensor resolution */
|
|
|
|
case SNIOC_SETRESOLUTION:
|
|
{
|
|
uint8_t res = arg - 9;
|
|
sninfo("set resolution: %ld\n", arg);
|
|
if (res >= DS18B20_RESMIN && res <= DS18B20_RESMAX)
|
|
{
|
|
ret = ds18b20_set_res(priv, DS18B20_RES_CONV(res));
|
|
}
|
|
else
|
|
{
|
|
ret = -EINVAL;
|
|
}
|
|
}
|
|
break;
|
|
|
|
default:
|
|
snerr("ERROR: Unrecognized cmd: %d\n", cmd);
|
|
ret = -ENOTTY;
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: ds18b20_active
|
|
*
|
|
* Description: Interface function of struct sensor_ops_s.
|
|
*
|
|
* Return:
|
|
* OK - on success
|
|
****************************************************************************/
|
|
|
|
static int ds18b20_active(FAR struct sensor_lowerhalf_s *lower,
|
|
FAR struct file *filep,
|
|
bool enabled)
|
|
{
|
|
#ifdef CONFIG_SENSORS_DS18B20_POLL
|
|
bool start_thread = false;
|
|
struct ds18b20_dev_s *priv = (FAR struct ds18b20_dev_s *)lower;
|
|
|
|
if (enabled)
|
|
{
|
|
if (!priv->sensor.enabled)
|
|
{
|
|
start_thread = true;
|
|
}
|
|
}
|
|
|
|
priv->sensor.enabled = enabled;
|
|
|
|
if (start_thread == true)
|
|
{
|
|
/* Wake up the thread */
|
|
|
|
nxsem_post(&priv->run);
|
|
}
|
|
#endif
|
|
|
|
return OK;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: ds18b20_set_interval
|
|
*
|
|
* Description: Interface function of struct sensor_ops_s.
|
|
*
|
|
* Return:
|
|
* OK - on success
|
|
****************************************************************************/
|
|
|
|
#ifdef CONFIG_SENSORS_DS18B20_POLL
|
|
static int ds18b20_set_interval(FAR struct sensor_lowerhalf_s *lower,
|
|
FAR struct file *filep,
|
|
FAR uint32_t *period_us)
|
|
{
|
|
FAR struct ds18b20_dev_s *priv = (FAR struct ds18b20_dev_s *)lower;
|
|
priv->interval = *period_us;
|
|
return OK;
|
|
}
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Name: ds18b20_thread
|
|
*
|
|
* Description: Thread for performing interval measurement cycle and data
|
|
* read.
|
|
*
|
|
* Parameter:
|
|
* argc - Number of arguments
|
|
* argv - Pointer to argument list
|
|
****************************************************************************/
|
|
|
|
#ifdef CONFIG_SENSORS_DS18B20_POLL
|
|
static int ds18b20_thread(int argc, char** argv)
|
|
{
|
|
uint16_t orawdata;
|
|
FAR struct ds18b20_dev_s *priv = (FAR struct ds18b20_dev_s *)
|
|
((uintptr_t)strtoul(argv[1], NULL, 16));
|
|
|
|
/* Set initial value to out of measurement range to ensure that the first
|
|
* data read leads to an upper notification.
|
|
*/
|
|
|
|
orawdata = 0xffff;
|
|
|
|
while (true)
|
|
{
|
|
int ret;
|
|
struct ds18b20_sensor_data_s data;
|
|
FAR struct ds18b20_sensor_s *sensor = &priv->sensor;
|
|
FAR struct ds18b20_alarm_s *alarm = &priv->reg.alarm;
|
|
|
|
if (!sensor->enabled)
|
|
{
|
|
/* Waiting to be woken up */
|
|
|
|
nxsem_wait(&priv->run);
|
|
}
|
|
|
|
if (alarm->wakeup == true)
|
|
{
|
|
/* Perform a temperature conversion to update the alarm flag */
|
|
|
|
ret = ds18b20_measure(priv);
|
|
if (!ret)
|
|
{
|
|
/* Wait until temperature conversion is done and the alarm flag
|
|
* is up to date.
|
|
*/
|
|
|
|
nxsig_usleep(g_res_timeout[DS18B20_RES_VAL(priv->reg.res)]);
|
|
|
|
/* Check for existing temperature alarm */
|
|
|
|
ret = ds18b20_isalarm(priv->master, &priv->config);
|
|
if (ret == 1)
|
|
{
|
|
ret = ds18b20_measure_read(priv, &data);
|
|
if (!ret && sensor->enabled == true)
|
|
{
|
|
/* Notify upper */
|
|
|
|
ds18b20_notify(priv, &data);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Default nofitication when temperature has been changed */
|
|
|
|
ret = ds18b20_measure_read(priv, &data);
|
|
if (!ret)
|
|
{
|
|
uint16_t rawtemp = ds18b20_rawtemp(data.spad);
|
|
|
|
if (sensor->enabled == true && orawdata != rawtemp)
|
|
{
|
|
ds18b20_notify(priv, &data);
|
|
}
|
|
|
|
/* Store the last sensor data for later comparison */
|
|
|
|
orawdata = ds18b20_rawtemp(data.spad);
|
|
}
|
|
}
|
|
|
|
/* Sleeping thread before fetching the next sensor data */
|
|
|
|
nxsig_usleep(priv->interval);
|
|
}
|
|
|
|
return OK;
|
|
}
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: ds18b20_register
|
|
*
|
|
* Description:
|
|
* Register the DS18B20 character device.
|
|
*
|
|
* Input Parameters:
|
|
* devno - The user specifies device number, from 0.
|
|
* onewire - An instance of the 1wire interface to communicate with DS18B20
|
|
* sensor.
|
|
* romcode - The ROM code of the DS18B20.
|
|
*
|
|
* Returned Value:
|
|
* Zero (OK) on success; a negated errno value on failure.
|
|
****************************************************************************/
|
|
|
|
int ds18b20_register(int devno, FAR struct onewire_master_s *onewire,
|
|
uint64_t romcode)
|
|
{
|
|
int ret;
|
|
struct ds18b20_sensor_s *tmp;
|
|
#ifdef CONFIG_SENSORS_DS18B20_POLL
|
|
FAR char *argv[2];
|
|
char arg1[32];
|
|
#endif
|
|
|
|
/* Sanity check */
|
|
|
|
if (!onewire)
|
|
{
|
|
snerr("Invalid 1wire instance\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Initialize the DS18B20 device structure */
|
|
|
|
FAR struct ds18b20_dev_s *priv = (FAR struct ds18b20_dev_s *)
|
|
kmm_malloc(sizeof(struct ds18b20_dev_s));
|
|
|
|
if (priv == NULL)
|
|
{
|
|
snerr("ERROR: Failed to allocate instance\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
priv->master = onewire;
|
|
priv->config.romcode = romcode;
|
|
priv->reg.res = DS18B20_RES_CONV(DS18B20_RESMAX);
|
|
priv->reg.alarm.thigh = DS18B20_TALARM_MAX;
|
|
priv->reg.alarm.tlow = DS18B20_TALARM_MIN;
|
|
#ifdef CONFIG_SENSORS_DS18B20_POLL
|
|
priv->reg.alarm.wakeup = false;
|
|
priv->interval = CONFIG_SENSORS_DS18B20_POLL_INTERVAL;
|
|
|
|
nxsem_init(&priv->run, 0, 0);
|
|
#endif
|
|
|
|
/* Temperature register */
|
|
|
|
tmp = &priv->sensor;
|
|
#ifdef CONFIG_SENSORS_DS18B20_POLL
|
|
tmp->enabled = false;
|
|
#endif
|
|
tmp->lower.ops = &g_ds18b20_ops;
|
|
tmp->lower.type = SENSOR_TYPE_AMBIENT_TEMPERATURE;
|
|
tmp->lower.uncalibrated = false;
|
|
tmp->lower.nbuffer = 1;
|
|
ret = sensor_register(&tmp->lower, devno);
|
|
if (ret < 0)
|
|
{
|
|
goto sensor_err;
|
|
}
|
|
|
|
#ifdef CONFIG_SENSORS_DS18B20_POLL
|
|
|
|
/* Create thread for polling sensor data */
|
|
|
|
snprintf(arg1, 16, "%p", priv);
|
|
argv[0] = arg1;
|
|
argv[1] = NULL;
|
|
ret = kthread_create("ds18b20_thread", SCHED_PRIORITY_DEFAULT,
|
|
CONFIG_SENSORS_DS18B20_THREAD_STACKSIZE,
|
|
ds18b20_thread, argv);
|
|
if (ret > 0)
|
|
#endif
|
|
{
|
|
return OK;
|
|
}
|
|
|
|
sensor_err:
|
|
sensor_unregister(&priv->sensor.lower, devno);
|
|
kmm_free(priv);
|
|
return ret;
|
|
}
|
|
#endif /* CONFIG_1WIRE && CONFIG_SENSORS_DS18B20 */
|