/**************************************************************************** * drivers/sensors/adxl345_base.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 "adxl345.h" #if defined(CONFIG_SENSORS_ADXL345) /**************************************************************************** * Private Types ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /* Character driver methods */ static ssize_t adxl345_read(FAR struct file *filep, FAR char *buffer, size_t len); /**************************************************************************** * Private Data ****************************************************************************/ /* This the vtable that supports the character driver interface */ static const struct file_operations g_adxl345fops = { NULL, /* open */ NULL, /* close */ adxl345_read, /* read */ }; /**************************************************************************** * Name: adxl345_read * * Description: * Standard character driver read method. * ****************************************************************************/ static ssize_t adxl345_read(FAR struct file *filep, FAR char *buffer, size_t len) { FAR struct inode *inode; FAR struct adxl345_dev_s *priv; struct adxl345_sample_s sample; int ret; sninfo("len=%d\n", len); inode = filep->f_inode; DEBUGASSERT(inode->i_private); priv = inode->i_private; /* Verify that the caller has provided a buffer large enough to receive * the accelerometer data. */ if (len < sizeof(struct adxl345_sample_s)) { /* We could provide logic to break up a sample into segments and * handle smaller reads... but why? */ return -ENOSYS; } /* Get exclusive access to the driver data structure */ ret = nxmutex_lock(&priv->lock); if (ret < 0) { return ret; } /* Read accelerometer X Y Z axes */ sample.data_x = adxl345_getreg8(priv, ADXL345_DATAX1); sample.data_x = (sample.data_x << 8) | adxl345_getreg8(priv, ADXL345_DATAX0); sample.data_y = adxl345_getreg8(priv, ADXL345_DATAY1); sample.data_y = (sample.data_y << 8) | adxl345_getreg8(priv, ADXL345_DATAY0); sample.data_z = adxl345_getreg8(priv, ADXL345_DATAZ1); sample.data_z = (sample.data_z << 8) | adxl345_getreg8(priv, ADXL345_DATAZ0); add_sensor_randomness(sample.data_x); add_sensor_randomness((sample.data_z << 16) | sample.data_y); /* Return read sample */ buffer = (FAR char *) &sample; nxmutex_unlock(&priv->lock); return sizeof(struct adxl345_sample_s); } /**************************************************************************** * Name: adxl345_register * * Description: * This function will register the accelerometer driver as /dev/accelN where * N is the minor device number * * Input Parameters: * handle - The handle previously returned by adxl345_register * minor - The input device minor number * * Returned Value: * Zero is returned on success. Otherwise, a negated errno value is * returned to indicate the nature of the failure. * ****************************************************************************/ int adxl345_register(ADXL345_HANDLE handle, int minor) { FAR struct adxl345_dev_s *priv = (FAR struct adxl345_dev_s *)handle; char devname[DEV_NAMELEN]; int ret; sninfo("handle=%p minor=%d\n", handle, minor); DEBUGASSERT(priv); /* Get exclusive access to the device structure */ ret = nxmutex_lock(&priv->lock); if (ret < 0) { snerr("ERROR: nxsem_wait failed: %d\n", ret); return ret; } /* Initialize the structure fields to their default values */ priv->ofsx = 0; priv->ofsy = 0; priv->ofsz = 0; /* Register the character driver */ snprintf(devname, sizeof(devname), DEV_FORMAT, minor); ret = register_driver(devname, &g_adxl345fops, 0444, priv); if (ret < 0) { snerr("ERROR: Failed to register driver %s: %d\n", devname, ret); nxmutex_unlock(&priv->lock); return ret; } /* Indicate that the accelerometer was successfully initialized */ priv->status |= ADXL345_STAT_INITIALIZED; /* Accelerometer is initialized */ nxmutex_unlock(&priv->lock); return ret; } /**************************************************************************** * Name: adxl345_worker * * Description: * This is the "bottom half" of the ADXL345 interrupt handler * ****************************************************************************/ static void adxl345_worker(FAR void *arg) { FAR struct adxl345_dev_s *priv = (FAR struct adxl345_dev_s *)arg; uint8_t regval; DEBUGASSERT(priv && priv->config); /* Get the global interrupt status */ regval = adxl345_getreg8(priv, ADXL345_INT_SOURCE); /* Check for a data ready interrupt */ if ((regval & INT_DATA_READY) != 0) { /* Read accelerometer data to sample */ priv->sample.data_x = adxl345_getreg8(priv, ADXL345_DATAX1); priv->sample.data_x = (priv->sample.data_x << 8) | adxl345_getreg8(priv, ADXL345_DATAX0); priv->sample.data_y = adxl345_getreg8(priv, ADXL345_DATAY1); priv->sample.data_y = (priv->sample.data_y << 8) | adxl345_getreg8(priv, ADXL345_DATAY0); priv->sample.data_z = adxl345_getreg8(priv, ADXL345_DATAZ1); priv->sample.data_z = (priv->sample.data_z << 8) | adxl345_getreg8(priv, ADXL345_DATAZ0); } /* Re-enable the ADXL345 GPIO interrupt */ priv->config->enable(priv->config, true); } /**************************************************************************** * Name: adxl345_interrupt * * Description: * The ADXL345 interrupt handler * ****************************************************************************/ static void adxl345_interrupt(FAR struct adxl345_config_s *config, FAR void *arg) { FAR struct adxl345_dev_s *priv = (FAR struct adxl345_dev_s *)arg; int ret; DEBUGASSERT(priv && priv->config == config); /* Disable further interrupts */ config->enable(config, false); /* Check if interrupt work is already queue. If it is already busy, then * we already have interrupt processing in the pipeline and we need to do * nothing more. */ if (work_available(&priv->work)) { /* Yes.. Transfer processing to the worker thread. Since ADXL345 * interrupts are disabled while the work is pending, no special * action should be required to protect the work queue. */ ret = work_queue(HPWORK, &priv->work, adxl345_worker, priv, 0); if (ret != 0) { snerr("ERROR: Failed to queue work: %d\n", ret); } } /* Clear any pending interrupts and return success */ config->clear(config); } /**************************************************************************** * Name: adxl345_checkid * * Description: * Read and verify the ADXL345 chip ID * ****************************************************************************/ static int adxl345_checkid(FAR struct adxl345_dev_s *priv) { uint8_t devid = 0; /* Read device ID */ devid = adxl345_getreg8(priv, ADXL345_DEVID); sninfo("devid: %04x\n", devid); if (devid != (uint16_t) DEVID) { /* ID is not Correct */ return -ENODEV; } return OK; } /**************************************************************************** * Name: adxl345_reset * * Description: * Reset the ADXL345 * ****************************************************************************/ static void adxl345_reset(FAR struct adxl345_dev_s *priv) { /* ADXL345 doesn't have software reset */ /* Wait a bit to make the GOD of TIME happy */ nxsig_usleep(20 * 1000); } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: adxl345_instantiate * * Description: * Instantiate and configure the ADXL345 device driver to use the provided * I2C or SPIdevice instance. * * Input Parameters: * dev - An I2C or SPI driver instance * config - Persistent board configuration data * * Returned Value: * A non-zero handle is returned on success. This handle may then be used * to configure the ADXL345 driver as necessary. A NULL handle value is * returned on failure. * ****************************************************************************/ #ifdef CONFIG_ADXL345_SPI ADXL345_HANDLE adxl345_instantiate(FAR struct spi_dev_s *dev, FAR struct adxl345_config_s *config) #else ADXL345_HANDLE adxl345_instantiate(FAR struct i2c_master_s *dev, FAR struct adxl345_config_s *config) #endif { FAR struct adxl345_dev_s *priv; uint8_t regval; int ret; /* Allocate the ADXL345 driver instance */ priv = (FAR struct adxl345_dev_s *) kmm_zalloc(sizeof(struct adxl345_dev_s)); if (!priv) { snerr("ERROR: Failed to allocate the device structure!\n"); return NULL; } /* Initialize the device state structure */ nxmutex_init(&priv->lock); priv->config = config; #ifdef CONFIG_ADXL345_SPI priv->spi = dev; #else priv->i2c = dev; #endif /* Read and verify the ADXL345 device ID */ ret = adxl345_checkid(priv); if (ret < 0) { snerr("ERROR: Wrong Device ID!\n"); nxmutex_destroy(&priv->lock); kmm_free(priv); return NULL; } /* Generate ADXL345 Software reset */ adxl345_reset(priv); /* Configure the interrupt output pin to generate interrupts on high or low * level. */ regval = adxl345_getreg8(priv, ADXL345_DATA_FORMAT); #ifdef CONFIG_ADXL345_ACTIVELOW regval |= DATA_FMT_INT_INVERT; /* Pin polarity: Active low / falling edge */ #else regval &= ~DATA_FMT_INT_INVERT; /* Pin polarity: Active high / rising edge */ #endif adxl345_putreg8(priv, ADXL345_DATA_FORMAT, regval); /* Attach the ADXL345 interrupt handler. */ config->attach(config, (adxl345_handler_t)adxl345_interrupt, (FAR void *)priv); /* Leave standby mode */ adxl345_putreg8(priv, ADXL345_POWER_CTL, POWER_CTL_MEASURE); config->clear(config); config->enable(config, true); /* Enable interrupts */ adxl345_putreg8(priv, ADXL345_INT_ENABLE, INT_DATA_READY); /* Return our private data structure as an opaque handle */ return (ADXL345_HANDLE)priv; } #endif /* CONFIG_SENSORS_ADXL345 */