601 lines
18 KiB
C
601 lines
18 KiB
C
/****************************************************************************
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* drivers/sensors/mlx90393.c
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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 <string.h>
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#include <nuttx/kmalloc.h>
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#include <nuttx/wqueue.h>
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#include <nuttx/fs/fs.h>
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#include <nuttx/mutex.h>
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#include <nuttx/sensors/mlx90393.h>
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#include <nuttx/random.h>
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#if defined(CONFIG_SPI) && defined(CONFIG_SENSORS_MLX90393)
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/****************************************************************************
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* Private
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****************************************************************************/
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struct mlx90393_sensor_data_s
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{
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int16_t x_mag; /* Measurement result for x axis */
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int16_t y_mag; /* Measurement result for y axis */
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int16_t z_mag; /* Measurement result for z axis */
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uint16_t temperature; /* Measurement result for temperature sensor */
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};
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struct mlx90393_dev_s
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{
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FAR struct mlx90393_dev_s *flink; /* Supports a singly linked list
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* of drivers */
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FAR struct spi_dev_s *spi; /* Pointer to the SPI instance */
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FAR struct mlx90393_config_s *config; /* Pointer to the configuration of
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* the MLX90393 sensor */
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mutex_t datalock; /* Manages exclusive access to
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* this structure */
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struct mlx90393_sensor_data_s data; /* The data as measured by the
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* sensor */
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struct work_s work; /* The work queue is responsible
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* for retrieving the data from
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* the sensor after the arrival of
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* new data was signalled in an
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* interrupt */
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};
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/****************************************************************************
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* Private Function Prototypes
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****************************************************************************/
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static void mlx90393_start_burst_mode(FAR struct mlx90393_dev_s *dev);
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static void mlx90393_read_measurement_data(FAR struct mlx90393_dev_s *dev);
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static void mlx90393_read_register(FAR struct mlx90393_dev_s *dev,
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uint8_t const reg_addr,
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uint16_t *reg_data);
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static void mlx90393_write_register(FAR struct mlx90393_dev_s *dev,
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uint8_t const reg_addr,
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uint16_t const reg_data);
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static void mlx90393_reset(FAR struct mlx90393_dev_s *dev);
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static int mlx90393_interrupt_handler(int irq, FAR void *context);
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static void mlx90393_worker(FAR void *arg);
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static int mlx90393_open(FAR struct file *filep);
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static int mlx90393_close(FAR struct file *filep);
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static ssize_t mlx90393_read(FAR struct file *, FAR char *, size_t);
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static ssize_t mlx90393_write(FAR struct file *filep,
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FAR const char *buffer,
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size_t buflen);
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/****************************************************************************
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* Private Data
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****************************************************************************/
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static const struct file_operations g_mlx90393_fops =
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{
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mlx90393_open, /* open */
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mlx90393_close, /* close */
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mlx90393_read, /* read */
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mlx90393_write, /* write */
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};
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/* Single linked list to store instances of drivers */
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static struct mlx90393_dev_s *g_mlx90393_list = NULL;
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: mlx90393_start_burst_mode
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****************************************************************************/
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static void mlx90393_start_burst_mode(FAR struct mlx90393_dev_s *dev)
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{
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/* Lock the SPI bus so that only one device can access it at the same
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* time
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*/
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SPI_LOCK(dev->spi, true);
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/* Set CS to low which selects the MLX90393 */
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SPI_SELECT(dev->spi, dev->config->spi_devid, true);
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/* Start Burst Mode (Continuous Measurement on all channels) */
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SPI_SEND(dev->spi, MLX90393_SB | MLX90393_ZYXT_BM);
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/* Write an idle byte to retrieve the status byte */
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SPI_SEND(dev->spi, 0);
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/* Set CS to high which deselects the MLX90393 */
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SPI_SELECT(dev->spi, dev->config->spi_devid, false);
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/* Unlock the SPI bus */
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SPI_LOCK(dev->spi, false);
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}
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/****************************************************************************
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* Name: mlx90393_read_measurement_data
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****************************************************************************/
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static void mlx90393_read_measurement_data(FAR struct mlx90393_dev_s *dev)
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{
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int ret;
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/* Lock the SPI bus so that only one device can access it at the same
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* time
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*/
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SPI_LOCK(dev->spi, true);
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/* Set CS to low which selects the MLX90393 */
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SPI_SELECT(dev->spi, dev->config->spi_devid, true);
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/* Issue command to read measurement data on all channels */
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SPI_SEND(dev->spi, MLX90393_RM | MLX90393_ZYXT_BM);
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/* Write an idle byte to retrieve the status byte */
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SPI_SEND(dev->spi, 0);
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/* The data is output in the following order: T (MSB), T (LSB), X (MSB), X
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* (LSB), Y (MSB), Y (LSB), Z (MSB), Z (LSB)
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*/
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uint16_t temperature = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */
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temperature |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */
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uint16_t x_mag = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */
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x_mag |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */
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uint16_t y_mag = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */
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y_mag |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */
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uint16_t z_mag = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */
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z_mag |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */
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/* Set CS to high which deselects the MLX90393 */
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SPI_SELECT(dev->spi, dev->config->spi_devid, false);
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/* Unlock the SPI bus */
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SPI_LOCK(dev->spi, false);
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/* Acquire the mutex before the data is copied */
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ret = nxmutex_lock(&dev->datalock);
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if (ret != OK)
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{
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snerr("ERROR: Could not acquire dev->datalock: %d\n", ret);
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return;
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}
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/* Copy retrieve data to internal data structure */
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dev->data.temperature = temperature;
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dev->data.x_mag = (int16_t) (x_mag);
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dev->data.y_mag = (int16_t) (y_mag);
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dev->data.z_mag = (int16_t) (z_mag);
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/* Give back the mutex */
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nxmutex_unlock(&dev->datalock);
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/* Feed sensor data to entropy pool */
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add_sensor_randomness((x_mag << 17) ^ (y_mag << 9) ^ (z_mag << 1) ^
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temperature);
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}
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/****************************************************************************
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* Name: mlx90393_start_burst_mode
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****************************************************************************/
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static void mlx90393_reset(FAR struct mlx90393_dev_s *dev)
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{
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/* Lock the SPI bus so that only one device can access it at the same
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* time
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*/
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SPI_LOCK(dev->spi, true);
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/* Set CS to low which selects the MLX90393 */
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SPI_SELECT(dev->spi, dev->config->spi_devid, true);
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/* Issue reset command */
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SPI_SEND(dev->spi, MLX90393_RT);
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/* Write an idle byte to retrieve the status byte */
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SPI_SEND(dev->spi, 0);
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/* Set CS to high which deselects the MLX90393 */
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SPI_SELECT(dev->spi, dev->config->spi_devid, false);
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/* Unlock the SPI bus */
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SPI_LOCK(dev->spi, false);
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/* Wait a little so the device has time to perform a proper reset */
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up_mdelay(100);
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}
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/****************************************************************************
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* Name: mlx90393_read_register
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****************************************************************************/
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static void mlx90393_read_register(FAR struct mlx90393_dev_s *dev,
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uint8_t const reg_addr,
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uint16_t *reg_data)
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{
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/* Lock the SPI bus so that only one device can access it at the same
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* time
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*/
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SPI_LOCK(dev->spi, true);
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/* Set CS to low which selects the MLX90393 */
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SPI_SELECT(dev->spi, dev->config->spi_devid, true);
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/* Issue a read register command */
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SPI_SEND(dev->spi, MLX90393_RR);
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/* Send the register address which needs to be left shifted by 2 */
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SPI_SEND(dev->spi, (reg_addr << 2));
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/* Write an idle byte to retrieve the status byte */
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SPI_SEND(dev->spi, 0);
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*reg_data = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */
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*reg_data |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */
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/* Set CS to high which deselects the MLX90393 */
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SPI_SELECT(dev->spi, dev->config->spi_devid, false);
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/* Unlock the SPI bus */
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SPI_LOCK(dev->spi, false);
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}
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/****************************************************************************
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* Name: mlx90393_write_register
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****************************************************************************/
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static void mlx90393_write_register(FAR struct mlx90393_dev_s *dev,
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uint8_t const reg_addr,
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uint16_t const reg_data)
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{
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/* Lock the SPI bus so that only one device can access it at the same
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* time
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*/
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SPI_LOCK(dev->spi, true);
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/* Set CS to low which selects the MLX90393 */
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SPI_SELECT(dev->spi, dev->config->spi_devid, true);
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/* Issue a write register command */
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SPI_SEND(dev->spi, MLX90393_WR);
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/* Send the data high byte of the register */
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SPI_SEND(dev->spi, (uint8_t) ((reg_data & 0xff00) >> 8));
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/* Send the data low byte of the register */
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SPI_SEND(dev->spi, (uint8_t) (reg_data & 0x00ff));
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/* Send the register address which needs to be left shifted by 2 */
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SPI_SEND(dev->spi, (uint8_t) (reg_addr << 2));
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/* Write an idle byte to retrieve the status byte */
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SPI_SEND(dev->spi, 0);
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/* Set CS to high which deselects the MLX90393 */
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SPI_SELECT(dev->spi, dev->config->spi_devid, false);
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/* Unlock the SPI bus */
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SPI_LOCK(dev->spi, false);
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}
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/****************************************************************************
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* Name: mlx90393_interrupt_handler
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****************************************************************************/
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static int mlx90393_interrupt_handler(int irq, FAR void *context)
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{
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/* This function should be called upon a rising edge on the MLX90393 INT
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* pin since it signals that new data has been measured. (INT = DRDY).
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*/
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FAR struct mlx90393_dev_s *priv = 0;
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int ret;
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/* Find out which MLX90396 device caused the interrupt */
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for (priv = g_mlx90393_list; priv && priv->config->irq != irq;
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priv = priv->flink);
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DEBUGASSERT(priv != NULL);
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/* Task the worker with retrieving the latest sensor data. We should not do
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* this in a interrupt since it might take too long. Also we cannot lock
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* the SPI bus from within an interrupt.
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*/
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DEBUGASSERT(priv->work.worker == NULL);
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ret = work_queue(HPWORK, &priv->work, mlx90393_worker, priv, 0);
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if (ret < 0)
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{
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snerr("ERROR: Failed to queue work: %d\n", ret);
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return ret;
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}
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else
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{
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return OK;
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}
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}
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/****************************************************************************
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* Name: mlx90393_worker
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****************************************************************************/
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static void mlx90393_worker(FAR void *arg)
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{
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FAR struct mlx90393_dev_s *priv = (FAR struct mlx90393_dev_s *)(arg);
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DEBUGASSERT(priv != NULL);
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/* Read out the latest sensor data */
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mlx90393_read_measurement_data(priv);
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}
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/****************************************************************************
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* Name: mlx90393_open
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****************************************************************************/
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static int mlx90393_open(FAR struct file *filep)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct mlx90393_dev_s *priv = inode->i_private;
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static int const NUM_REGS = 10;
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int reg_addr;
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DEBUGASSERT(priv != NULL);
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/* Reset the device */
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mlx90393_reset(priv);
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#ifdef CONFIG_DEBUG_SENSORS_INFO
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/* Read the content of ALL registers for debug purposes */
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for (reg_addr = 0; reg_addr < NUM_REGS; reg_addr++)
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{
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uint16_t reg_content = 0;
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mlx90393_read_register(priv, reg_addr, ®_content);
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sninfo("R%d = %x\n", reg_addr, reg_content);
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}
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#endif
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/* Start the burst mode */
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mlx90393_start_burst_mode(priv);
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return OK;
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}
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/****************************************************************************
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* Name: mlx90393_close
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****************************************************************************/
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static int mlx90393_close(FAR struct file *filep)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct mlx90393_dev_s *priv = inode->i_private;
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DEBUGASSERT(priv != NULL);
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/* Reset the device */
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mlx90393_reset(priv);
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return OK;
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}
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/****************************************************************************
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* Name: mlx90393_read
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****************************************************************************/
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static ssize_t mlx90393_read(FAR struct file *filep, FAR char *buffer,
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size_t buflen)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct mlx90393_dev_s *priv = inode->i_private;
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FAR struct mlx90393_sensor_data_s *data;
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int ret;
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DEBUGASSERT(priv != NULL);
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/* Check if enough memory was provided for the read call */
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if (buflen < sizeof(struct mlx90393_sensor_data_s))
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{
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snerr("ERROR: "
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"Not enough memory for reading out a sensor data sample\n");
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return -ENOSYS;
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}
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/* Copy the sensor data into the buffer */
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/* Acquire the mutex before the data is copied */
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ret = nxmutex_lock(&priv->datalock);
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if (ret < 0)
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{
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snerr("ERROR: Could not acquire priv->datalock: %d\n", ret);
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return ret;
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}
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data = (FAR struct mlx90393_sensor_data_s *)buffer;
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memset(data, 0, sizeof(struct mlx90393_sensor_data_s));
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data->x_mag = priv->data.x_mag;
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data->y_mag = priv->data.y_mag;
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data->z_mag = priv->data.z_mag;
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data->temperature = priv->data.temperature;
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/* Give back the mutex */
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nxmutex_unlock(&priv->datalock);
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return sizeof(struct mlx90393_sensor_data_s);
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}
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/****************************************************************************
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* Name: mlx90393_write
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****************************************************************************/
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static ssize_t mlx90393_write(FAR struct file *filep, FAR const char *buffer,
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size_t buflen)
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{
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return -ENOSYS;
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: mlx90393_register
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*
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* Description:
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* Register the MLX90393 character device as 'devpath'
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*
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* Input Parameters:
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* devpath - The full path to the driver to register. E.g., "/dev/mag0"
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* spi - An instance of the SPI interface to use to communicate with
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* MLX90393
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* config - Describes the configuration of the MLX90393 part.
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*
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* Returned Value:
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* Zero (OK) on success; a negated errno value on failure.
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*
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****************************************************************************/
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int mlx90393_register(FAR const char *devpath, FAR struct spi_dev_s *spi,
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FAR struct mlx90393_config_s *config)
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{
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FAR struct mlx90393_dev_s *priv;
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int ret;
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/* Sanity check */
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DEBUGASSERT(spi != NULL);
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DEBUGASSERT(config != NULL);
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/* Initialize the MLX90393 device structure */
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priv = (FAR struct mlx90393_dev_s *)
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kmm_malloc(sizeof(struct mlx90393_dev_s));
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if (priv == NULL)
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{
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snerr("ERROR: Failed to allocate instance\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
priv->spi = spi;
|
|
priv->config = config;
|
|
|
|
priv->work.worker = NULL;
|
|
|
|
nxmutex_init(&priv->datalock); /* Initialize sensor data access mutex */
|
|
|
|
/* Setup SPI frequency and mode */
|
|
|
|
SPI_SETFREQUENCY(spi, MLX90393_SPI_FREQUENCY);
|
|
SPI_SETMODE(spi, MLX90393_SPI_MODE);
|
|
|
|
/* Attach the interrupt handler */
|
|
|
|
ret = priv->config->attach(priv->config, &mlx90393_interrupt_handler);
|
|
if (ret < 0)
|
|
{
|
|
snerr("ERROR: Failed to attach interrupt\n");
|
|
nxmutex_destroy(&priv->datalock);
|
|
kmm_free(priv);
|
|
return ret;
|
|
}
|
|
|
|
/* Register the character driver */
|
|
|
|
ret = register_driver(devpath, &g_mlx90393_fops, 0666, priv);
|
|
if (ret < 0)
|
|
{
|
|
snerr("ERROR: Failed to register driver: %d\n", ret);
|
|
nxmutex_destroy(&priv->datalock);
|
|
kmm_free(priv);
|
|
return ret;
|
|
}
|
|
|
|
/* Since we support multiple MLX90393 devices are supported, we will need
|
|
* to add this new instance to a list of device instances so that it can be
|
|
* found by the interrupt handler based on the received IRQ number.
|
|
*/
|
|
|
|
priv->flink = g_mlx90393_list;
|
|
g_mlx90393_list = priv;
|
|
|
|
return OK;
|
|
}
|
|
|
|
#endif /* CONFIG_SPI && CONFIG_SENSORS_MLX90393 */
|