/**************************************************************************** * drivers/sensors/bmg160.c * Character driver for the BMG160 3-Axis gyroscope. * * Copyright (C) 2016 DS-Automotion GmbH. All rights reserved. * Author: Alexander Entinger * Thomas Ilk * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #if defined(CONFIG_SPI) && defined(CONFIG_SENSORS_BMG160) /**************************************************************************** * Private ****************************************************************************/ struct bmg160_sensor_data_s { int16_t x_gyr; /* Measurement result for x axis */ int16_t y_gyr; /* Measurement result for y axis */ int16_t z_gyr; /* Measurement result for z axis */ }; struct bmg160_dev_s { FAR struct bmg160_dev_s *flink; /* Supports a singly linked list of * drivers */ FAR struct spi_dev_s *spi; /* Pointer to the SPI instance */ FAR struct bmg160_config_s *config; /* Pointer to the configuration of the * BMG160 sensor */ sem_t datasem; /* Manages exclusive access to this * structure */ struct bmg160_sensor_data_s data; /* The data as measured by the sensor */ struct work_s work; /* The work queue is responsible for * retrieving the data from the sensor * after the arrival of new data was * signalled in an interrupt */ }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ static void bmg160_read_register(FAR struct bmg160_dev_s *dev, uint8_t const reg_addr, uint8_t * reg_data); static void bmg160_write_register(FAR struct bmg160_dev_s *dev, uint8_t const reg_addr, uint8_t const reg_data); static void bmg160_reset(FAR struct bmg160_dev_s *dev); static void bmg160_read_measurement_data(FAR struct bmg160_dev_s *dev); static void bmg160_read_gyroscope_data(FAR struct bmg160_dev_s *dev, uint16_t * x_gyr, uint16_t * y_gyr, uint16_t * z_gyr); static int bmg160_interrupt_handler(int irq, FAR void *context); static void bmg160_worker(FAR void *arg); static int bmg160_open(FAR struct file *filep); static int bmg160_close(FAR struct file *filep); static ssize_t bmg160_read(FAR struct file *, FAR char *, size_t); static ssize_t bmg160_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); static int bmg160_ioctl(FAR struct file *filep, int cmd, unsigned long arg); /**************************************************************************** * Private Data ****************************************************************************/ static const struct file_operations g_bmg160_fops = { bmg160_open, bmg160_close, bmg160_read, bmg160_write, NULL, bmg160_ioctl #ifndef CONFIG_DISABLE_POLL , NULL #endif #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS , NULL #endif }; /* Single linked list to store instances of drivers */ static struct bmg160_dev_s *g_bmg160_list = NULL; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: bmg160_read_register ****************************************************************************/ static void bmg160_read_register(FAR struct bmg160_dev_s *dev, uint8_t const reg_addr, uint8_t * reg_data) { /* Lock the SPI bus so that only one device can access it at the same time */ SPI_LOCK(dev->spi, true); /* Set CS to low which selects the BMG160 */ SPI_SELECT(dev->spi, dev->config->spi_devid, true); /* Transmit the register address from where we want to read - the MSB needs * to be set to indicate the read indication. */ SPI_SEND(dev->spi, reg_addr | 0x80); /* Write an idle byte while receiving the required data */ *reg_data = (uint8_t) (SPI_SEND(dev->spi, 0)); /* Set CS to high which deselects the BMG160 */ SPI_SELECT(dev->spi, dev->config->spi_devid, false); /* Unlock the SPI bus */ SPI_LOCK(dev->spi, false); } /**************************************************************************** * Name: bmg160_write_register ****************************************************************************/ static void bmg160_write_register(FAR struct bmg160_dev_s *dev, uint8_t const reg_addr, uint8_t const reg_data) { /* Lock the SPI bus so that only one device can access it at the same time */ SPI_LOCK(dev->spi, true); /* Set CS to low which selects the BMG160 */ SPI_SELECT(dev->spi, dev->config->spi_devid, true); /* Transmit the register address from where we want to read */ SPI_SEND(dev->spi, reg_addr); /* Transmit the content which should be written in the register */ SPI_SEND(dev->spi, reg_data); /* Set CS to high which deselects the BMG160 */ SPI_SELECT(dev->spi, dev->config->spi_devid, false); /* Unlock the SPI bus */ SPI_LOCK(dev->spi, false); } /**************************************************************************** * Name: bmg160_reset ****************************************************************************/ static void bmg160_reset(FAR struct bmg160_dev_s *dev) { bmg160_write_register(dev, BMG160_BGW_SOFTRESET_REG, 0xB6); up_mdelay(100); } /**************************************************************************** * Name: bmg160_read_measurement_data ****************************************************************************/ static void bmg160_read_measurement_data(FAR struct bmg160_dev_s *dev) { int ret; /* Read Gyroscope */ uint16_t x_gyr = 0, y_gyr = 0, z_gyr = 0; bmg160_read_gyroscope_data(dev, &x_gyr, &y_gyr, &z_gyr); /* Aquire the semaphore before the data is copied */ ret = nxsem_wait(&dev->datasem); if (ret < 0) { snerr("ERROR: Could not aquire dev->datasem: %d\n", ret); DEBUGASSERT(ret == -EINTR || ret == -ECANCELED); return; } /* Copy retrieve data to internal data structure */ dev->data.x_gyr = (int16_t) (x_gyr); dev->data.y_gyr = (int16_t) (y_gyr); dev->data.z_gyr = (int16_t) (z_gyr); /* Give back the semaphore */ nxsem_post(&dev->datasem); /* Feed sensor data to entropy pool */ add_sensor_randomness((x_gyr << 16) ^ (y_gyr << 8) ^ z_gyr); } /**************************************************************************** * Name: bmg160_read_gyroscope_data ****************************************************************************/ static void bmg160_read_gyroscope_data(FAR struct bmg160_dev_s *dev, uint16_t * x_gyr, uint16_t * y_gyr, uint16_t * z_gyr) { /* Lock the SPI bus so that only one device can access it at the same time */ SPI_LOCK(dev->spi, true); /* Set CS to low which selects the BMG160 */ SPI_SELECT(dev->spi, dev->config->spi_devid, true); /* Transmit the register address from where we want to start reading. 0x80 * -> MSB is set -> Read Indication. */ SPI_SEND(dev->spi, (BMG160_RATE_X_LSB_REG | 0x80)); /* RX */ *x_gyr = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */ *x_gyr |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */ *y_gyr = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */ *y_gyr |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */ *z_gyr = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */ *z_gyr |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */ /* Set CS to high which deselects the BMG160 */ SPI_SELECT(dev->spi, dev->config->spi_devid, false); /* Unlock the SPI bus */ SPI_LOCK(dev->spi, false); } /**************************************************************************** * Name: bmg160_interrupt_handler ****************************************************************************/ static int bmg160_interrupt_handler(int irq, FAR void *context) { /* This function should be called upon a rising edge on the BMG160 new data * interrupt pin since it signals that new data has been measured. */ FAR struct bmg160_dev_s *priv = 0; int ret; /* Find out which BMG160 device caused the interrupt */ for (priv = g_bmg160_list; priv && priv->config->irq != irq; priv = priv->flink); DEBUGASSERT(priv != NULL); /* 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 * SPI bus from within an interrupt. */ DEBUGASSERT(priv->work.worker == NULL); ret = work_queue(HPWORK, &priv->work, bmg160_worker, priv, 0); if (ret < 0) { snerr("ERROR: Failed to queue work: %d\n", ret); return ret; } return OK; } /**************************************************************************** * Name: bmg160_worker ****************************************************************************/ static void bmg160_worker(FAR void *arg) { FAR struct bmg160_dev_s *priv = (FAR struct bmg160_dev_s *)(arg); DEBUGASSERT(priv != NULL); /* Read out the latest sensor data */ bmg160_read_measurement_data(priv); } /**************************************************************************** * Name: bmg160_open ****************************************************************************/ static int bmg160_open(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct bmg160_dev_s *priv = inode->i_private; #ifdef CONFIG_DEBUG_SENSORS_INFO uint8_t reg_content; #endif DEBUGASSERT(priv != NULL); /* Perform a reset */ bmg160_reset(priv); /* Configure the sensor for our needs */ /* Enable - the full scale range FS = +/- 250 °/s */ bmg160_write_register(priv, BMG160_RANGE_REG, BMG160_RANGE_REG_FIX_VAL_bm | BMG160_RANGE_REG_FSR_1_bm | BMG160_RANGE_REG_FSR_0_bm); /* Enable - the fastest data output rate ODR = 2000 Hz -> BW = 230 Hz */ bmg160_write_register(priv, BMG160_BW_REG, BMG160_BW_REG_ODR_0_bm); /* Enable - new data interrupt 1 */ bmg160_write_register(priv, BMG160_INT_EN_0_REG, BMG160_INT_EN_0_REG_DATA_EN_bm); /* Enable - active high level interrupt 1 - push-pull interrupt */ bmg160_write_register(priv, BMG160_INT_EN_1_REG, BMG160_INT_EN_1_REG_INT1_LVL_bm); /* Enable - map new data interrupt to INT1 */ bmg160_write_register(priv, BMG160_INT_MAP_1_REG, BMG160_INT_MAP_1_REG_INT1_DATA_bm); /* Read measurement data to ensure DRDY is low */ bmg160_read_measurement_data(priv); #ifdef CONFIG_DEBUG_SENSORS_INFO /* Read back the content of all control registers for debug purposes */ reg_content = 0; bmg160_read_register(priv, BMG160_RANGE_REG, ®_content); sninfo("BMG160_RANGE_REG = %04x\n", reg_content); bmg160_read_register(priv, BMG160_BW_REG, ®_content); sninfo("BMG160_BW_REG = %04x\n", reg_content); bmg160_read_register(priv, BMG160_INT_EN_0_REG, ®_content); sninfo("BMG160_INT_EN_0_REG = %04x\n", reg_content); bmg160_read_register(priv, BMG160_INT_EN_1_REG, ®_content); sninfo("BMG160_INT_EN_1_REG = %04x\n", reg_content); bmg160_read_register(priv, BMG160_INT_MAP_1_REG, ®_content); sninfo("BMG160_INT_MAP_1_REG = %04x\n", reg_content); #endif return OK; } /**************************************************************************** * Name: bmg160_close ****************************************************************************/ static int bmg160_close(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct bmg160_dev_s *priv = inode->i_private; DEBUGASSERT(priv != NULL); /* Perform a reset */ bmg160_reset(priv); return OK; } /**************************************************************************** * Name: bmg160_read ****************************************************************************/ static ssize_t bmg160_read(FAR struct file *filep, FAR char *buffer, size_t buflen) { FAR struct inode *inode = filep->f_inode; FAR struct bmg160_dev_s *priv = inode->i_private; FAR struct bmg160_sensor_data_s *data; int ret; DEBUGASSERT(priv != NULL); /* Check if enough memory was provided for the read call */ if (buflen < sizeof(FAR struct bmg160_sensor_data_s)) { snerr("ERROR: Not enough memory for reading out a sensor data sample\n"); return -ENOSYS; } /* Aquire the semaphore before the data is copied */ ret = nxsem_wait(&priv->datasem); if (ret < 0) { snerr("ERROR: Could not aquire priv->datasem: %d\n", ret); DEBUGASSERT(ret == -EINTR || ret == -ECANCELED); return ret; } /* Copy the sensor data into the buffer */ data = (FAR struct bmg160_sensor_data_s *)buffer; memset(data, 0, sizeof(FAR struct bmg160_sensor_data_s)); data->x_gyr = priv->data.x_gyr; data->y_gyr = priv->data.y_gyr; data->z_gyr = priv->data.z_gyr; /* Give back the semaphore */ nxsem_post(&priv->datasem); return sizeof(FAR struct bmg160_sensor_data_s); } /**************************************************************************** * Name: bmg160_write ****************************************************************************/ static ssize_t bmg160_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) { return -ENOSYS; } /**************************************************************************** * Name: bmg160_ioctl ****************************************************************************/ static int bmg160_ioctl(FAR struct file *filep, int cmd, unsigned long arg) { int ret = OK; switch (cmd) { /* Command was not recognized */ default: snerr("ERROR: Unrecognized cmd: %d\n", cmd); ret = -ENOTTY; break; } return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: bmg160_register * * Description: * Register the BMG160 character device as 'devpath' * * Input Parameters: * devpath - The full path to the driver to register. E.g., "/dev/gyr0" * spi - An instance of the SPI interface to use to communicate with * BMG160 * config - configuration for the BMG160 driver. For details see * description above. * * Returned Value: * Zero (OK) on success; a negated errno value on failure. * ****************************************************************************/ int bmg160_register(FAR const char *devpath, FAR struct spi_dev_s *spi, FAR struct bmg160_config_s *config) { FAR struct bmg160_dev_s *priv; int ret; /* Sanity check */ DEBUGASSERT(spi != NULL); DEBUGASSERT(config != NULL); /* Initialize the BMG160 device structure */ priv = (FAR struct bmg160_dev_s *)kmm_malloc(sizeof(struct bmg160_dev_s)); if (priv == NULL) { snerr("ERROR: Failed to allocate instance\n"); return -ENOMEM; } priv->spi = spi; priv->config = config; priv->work.worker = NULL; /* Initialize sensor data access semaphore */ nxsem_init(&priv->datasem, 0, 1); /* Setup SPI frequency and mode */ SPI_SETFREQUENCY(spi, BMG160_SPI_FREQUENCY); SPI_SETMODE(spi, BMG160_SPI_MODE); /* Attach the interrupt handler */ ret = priv->config->attach(priv->config, &bmg160_interrupt_handler); if (ret < 0) { snerr("ERROR: Failed to attach interrupt\n"); return ret; } /* Register the character driver */ ret = register_driver(devpath, &g_bmg160_fops, 0666, priv); if (ret < 0) { snerr("ERROR: Failed to register driver: %d\n", ret); kmm_free(priv); nxsem_destroy(&priv->datasem); return ret; } /* Since we support multiple BMG160 devices, 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_bmg160_list; g_bmg160_list = priv; return OK; } #endif /* CONFIG_SPI && CONFIG_SENSORS_BMG160 */