/**************************************************************************** * drivers/sensors/lis3mdl.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include #if defined(CONFIG_SPI) && defined(CONFIG_SENSORS_LIS3MDL) /**************************************************************************** * Private ****************************************************************************/ struct lis3mdl_sensor_data_s { int16_t x_mag; /* Measurement result for x axis */ int16_t y_mag; /* Measurement result for y axis */ int16_t z_mag; /* Measurement result for z axis */ int16_t temperature; /* Measurement result for temperature sensor */ }; struct lis3mdl_dev_s { FAR struct lis3mdl_dev_s *flink; /* Supports a singly linked list of * drivers */ FAR struct spi_dev_s *spi; /* Pointer to the SPI instance */ FAR struct lis3mdl_config_s *config; /* Pointer to the configuration * of the LIS3MDL sensor */ mutex_t datalock; /* Manages exclusive access to this * structure */ struct lis3mdl_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 lis3mdl_read_register(FAR struct lis3mdl_dev_s *dev, uint8_t const reg_addr, uint8_t *reg_data); static void lis3mdl_write_register(FAR struct lis3mdl_dev_s *dev, uint8_t const reg_addr, uint8_t const reg_data); static void lis3mdl_reset(FAR struct lis3mdl_dev_s *dev); static void lis3mdl_read_measurement_data(FAR struct lis3mdl_dev_s *dev); static void lis3mdl_read_magnetic_data(FAR struct lis3mdl_dev_s *dev, uint16_t *x_mag, uint16_t *y_mag, uint16_t *z_mag); static void lis3mdl_read_temperature(FAR struct lis3mdl_dev_s *dev, uint16_t *temperature); static int lis3mdl_interrupt_handler(int irq, FAR void *context); static void lis3mdl_worker(FAR void *arg); static int lis3mdl_open(FAR struct file *filep); static int lis3mdl_close(FAR struct file *filep); static ssize_t lis3mdl_read(FAR struct file *filep, FAR char *buffer, size_t buflen); static ssize_t lis3mdl_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); /**************************************************************************** * Private Data ****************************************************************************/ static const struct file_operations g_lis3mdl_fops = { lis3mdl_open, /* open */ lis3mdl_close, /* close */ lis3mdl_read, /* read */ lis3mdl_write, /* write */ }; /* Single linked list to store instances of drivers */ static struct lis3mdl_dev_s *g_lis3mdl_list = 0; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: lis3mdl_read_register ****************************************************************************/ static void lis3mdl_read_register(FAR struct lis3mdl_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 LIS3MDL */ 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 LIS3MDL */ SPI_SELECT(dev->spi, dev->config->spi_devid, false); /* Unlock the SPI bus */ SPI_LOCK(dev->spi, false); } /**************************************************************************** * Name: lis3mdl_write_register ****************************************************************************/ static void lis3mdl_write_register(FAR struct lis3mdl_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 LIS3MDL */ 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 LIS3MDL */ SPI_SELECT(dev->spi, dev->config->spi_devid, false); /* Unlock the SPI bus */ SPI_LOCK(dev->spi, false); } /**************************************************************************** * Name: lis3mdl_reset ****************************************************************************/ static void lis3mdl_reset(FAR struct lis3mdl_dev_s *dev) { lis3mdl_write_register(dev, LIS3MDL_CTRL_REG_2, LIS3MDL_CTRL_REG_2_SOFT_RST_BM); up_mdelay(100); } /**************************************************************************** * Name: lis3mdl_interrupt_handler ****************************************************************************/ static void lis3mdl_read_measurement_data(FAR struct lis3mdl_dev_s *dev) { /* Magnetic data */ uint16_t x_mag = 0; uint16_t y_mag = 0; uint16_t z_mag = 0; lis3mdl_read_magnetic_data(dev, &x_mag, &y_mag, &z_mag); /* Temperature */ uint16_t temperature = 0; lis3mdl_read_temperature(dev, &temperature); /* Acquire the mutex before the data is copied */ int ret = nxmutex_lock(&dev->datalock); if (ret != OK) { snerr("ERROR: Could not acquire dev->datalock: %d\n", ret); return; } /* Copy retrieve data to internal data structure */ dev->data.x_mag = (int16_t) (x_mag); dev->data.y_mag = (int16_t) (y_mag); dev->data.z_mag = (int16_t) (z_mag); dev->data.temperature = (int16_t) (temperature); /* Give back the mutex */ nxmutex_unlock(&dev->datalock); /* Feed sensor data to entropy pool */ add_sensor_randomness((x_mag << 16) ^ (y_mag << 10) ^ (z_mag << 2) ^ temperature); } /**************************************************************************** * Name: lis3mdl_read_magnetic_data ****************************************************************************/ static void lis3mdl_read_magnetic_data(FAR struct lis3mdl_dev_s *dev, uint16_t * x_mag, uint16_t * y_mag, uint16_t * z_mag) { /* 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 LIS3MDL */ 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 0x40 -> MSB-1 (MS-Bit) is * set -> auto increment of address when reading multiple bytes. */ SPI_SEND(dev->spi, (LIS3MDL_OUT_X_L_REG | 0x80 | 0x40)); /* RX */ *x_mag = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */ *x_mag |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */ *y_mag = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */ *y_mag |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */ *z_mag = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */ *z_mag |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */ /* Set CS to high which deselects the LIS3MDL */ SPI_SELECT(dev->spi, dev->config->spi_devid, false); /* Unlock the SPI bus */ SPI_LOCK(dev->spi, false); } /**************************************************************************** * Name: lis3mdl_read_temperature ****************************************************************************/ static void lis3mdl_read_temperature(FAR struct lis3mdl_dev_s *dev, uint16_t * temperature) { /* 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 LIS3MDL */ 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 0x40 -> MSB-1 (MS-Bit) is * set -> auto increment of address when reading multiple bytes. */ SPI_SEND(dev->spi, (LIS3MDL_TEMP_OUT_L_REG | 0x80 | 0x40)); /* RX */ *temperature = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */ *temperature |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */ /* Set CS to high which deselects the LIS3MDL */ SPI_SELECT(dev->spi, dev->config->spi_devid, false); /* Unlock the SPI bus */ SPI_LOCK(dev->spi, false); } /**************************************************************************** * Name: lis3mdl_interrupt_handler ****************************************************************************/ static int lis3mdl_interrupt_handler(int irq, FAR void *context) { /* This function should be called upon a rising edge on the LIS3MDL DRDY * pin since it signals that new data has been measured. */ FAR struct lis3mdl_dev_s *priv = 0; int ret; /* Find out which LIS3MDL device caused the interrupt */ for (priv = g_lis3mdl_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, lis3mdl_worker, priv, 0); if (ret < 0) { snerr("ERROR: Failed to queue work: %d\n", ret); return ret; } else { return OK; } } /**************************************************************************** * Name: lis3mdl_worker ****************************************************************************/ static void lis3mdl_worker(FAR void *arg) { FAR struct lis3mdl_dev_s *priv = (FAR struct lis3mdl_dev_s *)(arg); DEBUGASSERT(priv != NULL); /* Read out the latest sensor data */ lis3mdl_read_measurement_data(priv); } /**************************************************************************** * Name: lis3mdl_open ****************************************************************************/ static int lis3mdl_open(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct lis3mdl_dev_s *priv = inode->i_private; uint8_t reg_content; uint8_t reg_addr; DEBUGASSERT(priv != NULL); /* Perform a reset */ lis3mdl_reset(priv); /* Enable * - the maximum full scale mode. * Full scale = +/- 1.6 mT (16 * Gauss). */ lis3mdl_write_register(priv, LIS3MDL_CTRL_REG_2, LIS3MDL_CTRL_REG_2_FS_1_BM | LIS3MDL_CTRL_REG_2_FS_0_BM); /* Enable - temperature sensor - ultra high performance mode (UMP) for X * and Y - fast output data rates This results in a output data rate of * 155 Hz for X and Y. */ lis3mdl_write_register(priv, LIS3MDL_CTRL_REG_1, LIS3MDL_CTRL_REG_1_TEMP_EN_BM | LIS3MDL_CTRL_REG_1_OM_1_BM | LIS3MDL_CTRL_REG_1_OM_0_BM | LIS3MDL_CTRL_REG_1_FAST_ODR_BM); /* Enable * - ultra high performance mode (UMP) for Z * This should result * to the same output data rate as for X and Y. */ lis3mdl_write_register(priv, LIS3MDL_CTRL_REG_4, LIS3MDL_CTRL_REG_4_OMZ_1_BM | LIS3MDL_CTRL_REG_4_OMZ_0_BM); /* Enable * - block data update for magnetic sensor data * This should * prevent race conditions when reading sensor data. */ lis3mdl_write_register(priv, LIS3MDL_CTRL_REG_5, LIS3MDL_CTRL_REG_5_BDU_BM); /* Enable continuous conversion mode - the device starts measuring now. */ lis3mdl_write_register(priv, LIS3MDL_CTRL_REG_3, 0); /* Read measurement data to ensure DRDY is low */ lis3mdl_read_measurement_data(priv); /* Read back the content of all control registers for debug purposes */ reg_content = 0; for (reg_addr = LIS3MDL_CTRL_REG_1; reg_addr <= LIS3MDL_CTRL_REG_5; reg_addr++) { lis3mdl_read_register(priv, reg_addr, ®_content); sninfo("R#%04x = %04x\n", reg_addr, reg_content); } lis3mdl_read_register(priv, LIS3MDL_STATUS_REG, ®_content); sninfo("STATUS_REG = %04x\n", reg_content); return OK; } /**************************************************************************** * Name: lis3mdl_close ****************************************************************************/ static int lis3mdl_close(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct lis3mdl_dev_s *priv = inode->i_private; DEBUGASSERT(priv != NULL); /* Perform a reset */ lis3mdl_reset(priv); return OK; } /**************************************************************************** * Name: lis3mdl_read ****************************************************************************/ static ssize_t lis3mdl_read(FAR struct file *filep, FAR char *buffer, size_t buflen) { FAR struct inode *inode = filep->f_inode; FAR struct lis3mdl_dev_s *priv = inode->i_private; FAR struct lis3mdl_sensor_data_s *data; int ret; DEBUGASSERT(priv != NULL); /* Check if enough memory was provided for the read call */ if (buflen < sizeof(FAR struct lis3mdl_sensor_data_s)) { snerr("ERROR: " "Not enough memory for reading out a sensor data sample\n"); return -ENOSYS; } /* Acquire the mutex before the data is copied */ ret = nxmutex_lock(&priv->datalock); if (ret < 0) { snerr("ERROR: Could not acquire priv->datalock: %d\n", ret); return ret; } /* Copy the sensor data into the buffer */ data = (FAR struct lis3mdl_sensor_data_s *)buffer; memset(data, 0, sizeof(FAR struct lis3mdl_sensor_data_s)); data->x_mag = priv->data.x_mag; data->y_mag = priv->data.y_mag; data->z_mag = priv->data.z_mag; data->temperature = priv->data.temperature; /* Give back the mutex */ nxmutex_unlock(&priv->datalock); return sizeof(FAR struct lis3mdl_sensor_data_s); } /**************************************************************************** * Name: lis3mdl_write ****************************************************************************/ static ssize_t lis3mdl_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) { return -ENOSYS; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: lis3mdl_register * * Description: * Register the LIS3MDL character device as 'devpath' * * Input Parameters: * devpath - The full path to the driver to register. E.g., "/dev/mag0" * spi - An instance of the SPI interface to use to communicate with * LIS3MDL * config - configuration for the LIS3MDL driver. For details see * description above. * * Returned Value: * Zero (OK) on success; a negated errno value on failure. * ****************************************************************************/ int lis3mdl_register(FAR const char *devpath, FAR struct spi_dev_s *spi, FAR struct lis3mdl_config_s const *config) { FAR struct lis3mdl_dev_s *priv; int ret; /* Sanity check */ DEBUGASSERT(spi != NULL); DEBUGASSERT(config != NULL); /* Initialize the LIS3MDL device structure */ priv = (FAR struct lis3mdl_dev_s *) kmm_malloc(sizeof(struct lis3mdl_dev_s)); if (priv == NULL) { 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, LIS3MDL_SPI_FREQUENCY); SPI_SETMODE(spi, LIS3MDL_SPI_MODE); /* Attach the interrupt handler */ ret = priv->config->attach(priv->config, &lis3mdl_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_lis3mdl_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 LIS3MDL 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_lis3mdl_list; g_lis3mdl_list = priv; return OK; } #endif /* CONFIG_SPI && CONFIG_SENSORS_LIS3MDL */