/**************************************************************************** * drivers/sensors/l3gd20.c * Character driver for the ST L3GD20 3-Axis gyroscope. * * Copyright (C) Gregory Nutt. All rights reserved. * Author: Mateusz Szafoni * * Based on drivers/sensors/lis3dsh.c * * 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_L3GD20) /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #if !defined(CONFIG_SCHED_HPWORK) # error Hi-priority work queue support is required (CONFIG_SCHED_HPWORK) #endif /**************************************************************************** * Private Types ****************************************************************************/ struct l3gd20_dev_s { FAR struct l3gd20_dev_s *flink; /* Supports a singly linked list of * drivers */ FAR struct spi_dev_s *spi; /* Pointer to the SPI instance */ FAR struct l3gd20_config_s *config; /* Pointer to the configuration of the * L3GD20 sensor */ sem_t datasem; /* Manages exclusive access to this * structure */ struct l3gd20_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 l3gd20_read_register(FAR struct l3gd20_dev_s *dev, uint8_t const reg_addr, uint8_t *reg_data); static void l3gd20_write_register(FAR struct l3gd20_dev_s *dev, uint8_t const reg_addr, uint8_t const reg_data); static void l3gd20_reset(FAR struct l3gd20_dev_s *dev); static void l3gd20_read_measurement_data(FAR struct l3gd20_dev_s *dev); static void l3gd20_read_gyroscope_data(FAR struct l3gd20_dev_s *dev, uint16_t *x_gyr, uint16_t *y_gyr, uint16_t *z_gyr); static void l3gd20_read_temperature(FAR struct l3gd20_dev_s *dev, uint8_t * temperature); static int l3gd20_interrupt_handler(int irq, FAR void *context); static void l3gd20_worker(FAR void *arg); static int l3gd20_open(FAR struct file *filep); static int l3gd20_close(FAR struct file *filep); static ssize_t l3gd20_read(FAR struct file *filep, FAR char *buffer, size_t buflen); static ssize_t l3gd20_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); static int l3gd20_ioctl(FAR struct file *filep, int cmd, unsigned long arg); /**************************************************************************** * Private Data ****************************************************************************/ static const struct file_operations g_l3gd20_fops = { l3gd20_open, l3gd20_close, l3gd20_read, l3gd20_write, NULL, l3gd20_ioctl #ifndef CONFIG_DISABLE_POLL , NULL #endif #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS , NULL #endif }; /* Single linked list to store instances of drivers */ static struct l3gd20_dev_s *g_l3gd20_list = NULL; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: l3gd20_read_register ****************************************************************************/ static void l3gd20_read_register(FAR struct l3gd20_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 L3GD20 */ 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 L3GD20 */ SPI_SELECT(dev->spi, dev->config->spi_devid, false); /* Unlock the SPI bus */ SPI_LOCK(dev->spi, false); } /**************************************************************************** * Name: l3gd20_write_register ****************************************************************************/ static void l3gd20_write_register(FAR struct l3gd20_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 L3GD20 */ 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 L3GD20 */ SPI_SELECT(dev->spi, dev->config->spi_devid, false); /* Unlock the SPI bus */ SPI_LOCK(dev->spi, false); } /**************************************************************************** * Name: l3gd20_reset ****************************************************************************/ static void l3gd20_reset(FAR struct l3gd20_dev_s *dev) { /* Reboot memory content */ l3gd20_write_register(dev, L3GD20_CTRL_REG_5, L3GD20_CTRL_REG_5_BOOT_bm); up_mdelay(100); } /**************************************************************************** * Name: l3gd20_read_measurement_data ****************************************************************************/ static void l3gd20_read_measurement_data(FAR struct l3gd20_dev_s *dev) { uint16_t x_gyr = 0; uint16_t y_gyr = 0; uint16_t z_gyr = 0; uint8_t temperature = 0; int ret; /* Read Gyroscope */ l3gd20_read_gyroscope_data(dev, &x_gyr, &y_gyr, &z_gyr); /* Read Temperature */ l3gd20_read_temperature(dev, &temperature); /* Aquire the semaphore before the data is copied */ ret = sem_wait(&dev->datasem); if (ret < 0) { snerr("ERROR: Could not aquire dev->datasem: %d\n", ret); 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 */ sem_post(&dev->datasem); /* Feed sensor data to entropy pool */ add_sensor_randomness((x_gyr << 16) ^ (y_gyr << 8) ^ (z_gyr << 0)); } /**************************************************************************** * Name: l3gd20_read_gyroscope_data ****************************************************************************/ static void l3gd20_read_gyroscope_data(FAR struct l3gd20_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 L3GD20 */ 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, (L3GD20_OUT_X_L_REG | 0x80 | 0x40)); /* 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 L3GD20 */ SPI_SELECT(dev->spi, dev->config->spi_devid, false); /* Unlock the SPI bus */ SPI_LOCK(dev->spi, false); } /**************************************************************************** * Name: l3gd20_read_temperature ****************************************************************************/ static void l3gd20_read_temperature(FAR struct l3gd20_dev_s* dev, uint8_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 L3GD20 */ 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, (L3GD20_OUT_TEMP_REG | 0x80)); /* RX */ *temperature = (SPI_SEND(dev->spi, 0)); /* Set CS to high which deselects the L3GD20 */ SPI_SELECT(dev->spi, dev->config->spi_devid, false); /* Unlock the SPI bus */ SPI_LOCK(dev->spi, false); } /**************************************************************************** * Name: l3gd20_interrupt_handler ****************************************************************************/ static int l3gd20_interrupt_handler(int irq, FAR void* context) { /* This function should be called upon a rising edge on the L3GD20 new data * interrupt pin since it signals that new data has been measured. */ FAR struct l3gd20_dev_s *priv = 0; int ret; /* Find out which L3GD20 device caused the interrupt */ for (priv = g_l3gd20_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, l3gd20_worker, priv, 0); if (ret < 0) { snerr("ERROR: Failed to queue work: %d\n", ret); return ret; } return OK; } /**************************************************************************** * Name: l3gd20_worker ****************************************************************************/ static void l3gd20_worker(FAR void *arg) { FAR struct l3gd20_dev_s *priv = (FAR struct l3gd20_dev_s *)(arg); DEBUGASSERT(priv != NULL); /* Read out the latest sensor data */ l3gd20_read_measurement_data(priv); } /**************************************************************************** * Name: l3gd20_open ****************************************************************************/ static int l3gd20_open(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct l3gd20_dev_s *priv = inode->i_private; #ifdef CONFIG_DEBUG_SENSORS_INFO uint8_t reg_content; uint8_t reg_addr; #endif DEBUGASSERT(priv != NULL); /* Perform a reset */ l3gd20_reset(priv); /* Enable DRDY signal on INT 2 */ l3gd20_write_register(priv, L3GD20_CTRL_REG_3, L3GD20_CTRL_REG_3_I2_DRDY_bm); /* Enable the maximum full scale mode. * Enable block data update for gyro sensor data. * This should prevent race conditions when reading sensor data. */ l3gd20_write_register(priv, L3GD20_CTRL_REG_4, L3GD20_CTRL_REG_4_BDU_bm | L3GD20_CTRL_REG_4_FS_1_bm | L3GD20_CTRL_REG_4_FS_0_bm); /* Enable X,Y,Z axis * DR=00 -> Output data rate = 95 Hz, Cut-off = 12.5 */ l3gd20_write_register(priv, L3GD20_CTRL_REG_1, L3GD20_CTRL_REG_1_POWERDOWN_bm | L3GD20_CTRL_REG_1_X_EN_bm | L3GD20_CTRL_REG_1_Y_EN_bm | L3GD20_CTRL_REG_1_Z_EN_bm); /* Read measurement data to ensure DRDY is low */ l3gd20_read_measurement_data(priv); /* Read back the content of all control registers for debug purposes */ #ifdef CONFIG_DEBUG_SENSORS_INFO reg_content = 0; l3gd20_read_register(priv, L3GD20_WHO_AM_I, ®_content); sninfo("WHO_AM_I_REG = %04x\n", reg_content); for (reg_addr = L3GD20_CTRL_REG_1; reg_addr <= L3GD20_CTRL_REG_5; reg_addr++) { l3gd20_read_register(priv, reg_addr, ®_content); sninfo("R#%04x = %04x\n", reg_addr, reg_content); } l3gd20_read_register(priv, L3GD20_STATUS_REG, ®_content); sninfo("STATUS_REG = %04x\n", reg_content); #endif return OK; } /**************************************************************************** * Name: l3gd20_close ****************************************************************************/ static int l3gd20_close(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct l3gd20_dev_s *priv = inode->i_private; DEBUGASSERT(priv != NULL); /* Perform a reset */ l3gd20_reset(priv); return OK; } /**************************************************************************** * Name: l3gd20_read ****************************************************************************/ static ssize_t l3gd20_read(FAR struct file *filep, FAR char *buffer, size_t buflen) { FAR struct inode *inode = filep->f_inode; FAR struct l3gd20_dev_s *priv = inode->i_private; FAR struct l3gd20_sensor_data_s *data; int ret; DEBUGASSERT(priv != NULL); /* Check if enough memory was provided for the read call */ if (buflen < sizeof(FAR struct l3gd20_sensor_data_s)) { snerr("ERROR: Not enough memory for reading out a sensor data sample\n"); return -ENOSYS; } /* Acquire the semaphore before the data is copied */ ret = sem_wait(&priv->datasem); if (ret < 0) { int errcode = errno; snerr("ERROR: Could not aquire priv->datasem: %d\n", errcode); return -errcode; } /* Copy the sensor data into the buffer */ data = (FAR struct l3gd20_sensor_data_s *)buffer; memset(data, 0, sizeof(FAR struct l3gd20_sensor_data_s)); data->x_gyr = priv->data.x_gyr; data->y_gyr = priv->data.y_gyr; data->z_gyr = priv->data.z_gyr; data->temperature = priv->data.temperature; /* Give back the semaphore */ sem_post(&priv->datasem); return sizeof(FAR struct l3gd20_sensor_data_s); } /**************************************************************************** * Name: l3gd20_write ****************************************************************************/ static ssize_t l3gd20_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) { return -ENOSYS; } /**************************************************************************** * Name: l3gd20_ioctl ****************************************************************************/ static int l3gd20_ioctl(FAR struct file *filep, int cmd, unsigned long arg) { int ret = OK; switch (cmd) { /* @TODO */ /* Command was not recognized */ default: snerr("ERROR: Unrecognized cmd: %d\n", cmd); ret = -ENOTTY; break; } return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: l3gd20_register * * Description: * Register the L3DF20 character device as 'devpath'. * * Input Parameters: * devpath - The full path to the driver to register, e.g., "/dev/gyr0". * spi - An SPI driver instance. * config - configuration for the L3GD20 driver. * * Returned Value: * Zero (OK) on success; a negated errno value on failure. * ****************************************************************************/ int l3gd20_register(FAR const char *devpath, FAR struct spi_dev_s *spi, FAR struct l3gd20_config_s *config) { FAR struct l3gd20_dev_s *priv; int ret = OK; /* Sanity check */ DEBUGASSERT(spi != NULL); DEBUGASSERT(config != NULL); /* Initialize the L3GD20 device structure */ priv = (FAR struct l3gd20_dev_s *)kmm_malloc(sizeof(struct l3gd20_dev_s)); if (priv == NULL) { snerr("ERROR: Failed to allocate instance\n"); ret = -ENOMEM; goto errout; } priv->spi = spi; priv->config = config; priv->work.worker = NULL; priv->data.x_gyr = 0; priv->data.y_gyr = 0; priv->data.z_gyr = 0; priv->data.temperature = 0; /* Initialize sensor data access semaphore */ sem_init(&priv->datasem, 0, 1); /* Setup SPI frequency and mode */ SPI_SETFREQUENCY(spi, L3GD20_SPI_FREQUENCY); SPI_SETMODE(spi, L3GD20_SPI_MODE); /* Attach the interrupt handler */ ret = priv->config->attach(priv->config, &l3gd20_interrupt_handler); if (ret < 0) { snerr("ERROR: Failed to attach interrupt\n"); goto errout; } /* Register the character driver */ ret = register_driver(devpath, &g_l3gd20_fops, 0666, priv); if (ret < 0) { snerr("ERROR: Failed to register driver: %d\n", ret); kmm_free(priv); sem_destroy(&priv->datasem); goto errout; } /* Since we support multiple L3GD20 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_l3gd20_list; g_l3gd20_list = priv; errout: return ret; } #endif /* CONFIG_SPI && CONFIG_SENSORS_L3GD20 */