/**************************************************************************** * drivers/sensors/mlx90614.c * Character driver for the Melexis MLX90614 Infrared Thermometer * * Copyright (C) 2018 Alan Carvalho de Assis. All rights reserved. * Author: Alan Carvalho de Assis * * 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 #include #ifdef CONFIG_MLX90614_CRC #include #endif #if defined(CONFIG_I2C) && defined(CONFIG_SENSORS_MLX90614) /**************************************************************************** * Pre-process Definitions ****************************************************************************/ /**************************************************************************** * Private Types ****************************************************************************/ struct mlx90614_dev_s { FAR struct i2c_master_s *i2c; /* I2C interface */ uint8_t addr; /* I2C address */ }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ /* I2C Helpers */ static int mlx90614_read_word(FAR struct mlx90614_dev_s *priv, uint8_t cmd, FAR uint16_t *regval); static int mlx90614_write_word(FAR struct mlx90614_dev_s *priv, uint8_t cmd, uint16_t regval); /* Character driver methods */ static int mlx90614_open(FAR struct file *filep); static int mlx90614_close(FAR struct file *filep); static ssize_t mlx90614_read(FAR struct file *filep, FAR char *buffer, size_t buflen); static ssize_t mlx90614_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); static int mlx90614_ioctl(FAR struct file *filep, int cmd, unsigned long arg); /**************************************************************************** * Private Data ****************************************************************************/ static const struct file_operations g_mlx90614_fops = { mlx90614_open, /* open */ mlx90614_close, /* close */ mlx90614_read, /* read */ mlx90614_write, /* write */ NULL, /* seek */ mlx90614_ioctl, /* ioctl */ NULL /* poll */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS , NULL /* unlink */ #endif }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: mlx90614_read_word * * Description: * Read 16-bit register * ****************************************************************************/ static int mlx90614_read_word(FAR struct mlx90614_dev_s *priv, uint8_t cmd, FAR uint16_t *regval) { struct i2c_config_s config; #ifdef CONFIG_MLX90614_CRC uint8_t checkcrc[6]; uint8_t *buffer; #else uint8_t buffer[3]; #endif uint8_t crc; int ret; #ifdef CONFIG_MLX90614_CRC /* Recreate the I2C byte sequence to check the CRC PEC field */ checkcrc[0] = I2C_WRITEADDR8(priv->addr); checkcrc[1] = cmd; checkcrc[2] = I2C_READADDR8(priv->addr); /* Point "buffer" to checkcrc[3] to fill it with received bytes */ buffer = (uint8_t *) &checkcrc[3]; #endif /* Set up the I2C configuration */ config.frequency = 100000; config.address = priv->addr; config.addrlen = 7; /* Write the Command and read 16-bits + PEC from the device */ ret = i2c_writeread(priv->i2c, &config, (FAR const uint8_t *) &cmd, 1, buffer, 3); if (ret < 0) { snerr ("i2c_writeread failed: %d\n", ret); return ret; } /* Copy the content of the buffer to the location of the uint16_t pointer */ *regval = (uint16_t)(buffer[0] | (buffer[1] << 8)); sninfo("value[0]: %02x | value[1]: %02x | value[2]: %02x | ret: %d\n", buffer[0], buffer[1], buffer[2], ret); #ifdef CONFIG_MLX90614_CRC crc = crc8ccitt(checkcrc, 5); sninfo("Calculated CRC: 0x%02X\n", crc); if (crc != buffer[2]) { snerr("Invalid CRC! Expected: 0x%02X read: 0x%02X\n", crc, buffer[2]); return -EFAULT; } #endif return OK; } /**************************************************************************** * Name: mlx90614_write_word * * Description: * Write to a 16-bit register * ****************************************************************************/ static int mlx90614_write_word(FAR struct mlx90614_dev_s *priv, uint8_t cmd, uint16_t regval) { struct i2c_config_s config; uint8_t pkgcrc[5]; uint8_t *buffer; uint8_t crc; int ret; /* Set up the I2C configuration */ config.frequency = 100000; config.address = priv->addr; config.addrlen = 7; /* First write 0x00 0x00 to erase the EEPROM */ pkgcrc[0] = I2C_WRITEADDR8(priv->addr); pkgcrc[1] = cmd; pkgcrc[2] = 0x00; pkgcrc[3] = 0x00; /* Generate the CRC to put in the PEC field */ crc = crc8ccitt(pkgcrc, 4); sninfo("Generated CRC: 0x%02X\n", crc); pkgcrc[4] = crc; buffer = &(pkgcrc[1]); /* Write the Command + 2 Bytes + PEC to device */ ret = i2c_write(priv->i2c, &config, (FAR const uint8_t *) buffer, 4); if (ret < 0) { snerr ("i2c_writeread failed: %d\n", ret); return ret; } /* Wait the EEPROM erase */ nxsig_usleep(10 * 1000); /* Create the I2C command that will be sent to device */ pkgcrc[0] = I2C_WRITEADDR8(priv->addr); pkgcrc[1] = cmd; pkgcrc[2] = (regval & 0xff); pkgcrc[3] = (regval & 0xff00) >> 8; /* Generate the CRC to put in the PEC field */ crc = crc8ccitt(pkgcrc, 4); sninfo("Generated CRC: 0x%02X\n", crc); pkgcrc[4] = crc; /* Write the Command + 2 Bytes + PEC to device */ ret = i2c_write(priv->i2c, &config, (FAR const uint8_t *) buffer, 4); if (ret < 0) { snerr ("i2c_writeread failed: %d\n", ret); return ret; } sninfo("New address 0x%02x stored correctly!\n", regval); return OK; } /**************************************************************************** * Name: mlx90614_open * * Description: * This function is called whenever the MLX90614 device is opened. * ****************************************************************************/ static int mlx90614_open(FAR struct file *filep) { return OK; } /**************************************************************************** * Name: mlx90614_close * * Description: * This routine is called when the MLX90614 device is closed. * ****************************************************************************/ static int mlx90614_close(FAR struct file *filep) { return OK; } /**************************************************************************** * Name: mlx90614_read ****************************************************************************/ static ssize_t mlx90614_read(FAR struct file *filep, FAR char *buffer, size_t buflen) { FAR struct inode *inode; FAR struct mlx90614_dev_s *priv; FAR struct mlx90614_temp_s *temp = (FAR struct mlx90614_temp_s *)buffer; uint8_t cmd; int ret; DEBUGASSERT(filep); inode = filep->f_inode; DEBUGASSERT(inode && inode->i_private); priv = (FAR struct mlx90614_dev_s *)inode->i_private; /* Check if the user is reading the right size */ if (buflen != sizeof(struct mlx90614_temp_s)) { snerr("ERROR: You need to read 2 bytes from this sensor!\n"); return -EINVAL; } /* Read Ambient Temperature sensor */ cmd = MLX90614_CMD_RAM_ACCESS | MLX90614_TA; ret = mlx90614_read_word(priv, cmd, &(temp->ta)); if (ret < 0) { snerr("ERROR: Error reading thermometer sensor!\n"); return ret; } /* Read Object1 Temperature sensor */ cmd = MLX90614_CMD_RAM_ACCESS | MLX90614_TOBJ1; ret = mlx90614_read_word(priv, cmd, &(temp->tobj1)); if (ret < 0) { snerr("ERROR: Error reading thermometer sensor!\n"); return ret; } /* Read Object2 Temperature sensor - some sensor doesn't have it */ cmd = MLX90614_CMD_RAM_ACCESS | MLX90614_TOBJ2; ret = mlx90614_read_word(priv, cmd, &(temp->tobj2)); if (ret < 0) { snerr("ERROR: Error reading thermometer sensor!\n"); return ret; } return buflen; } /**************************************************************************** * Name: mlx90614_write ****************************************************************************/ static ssize_t mlx90614_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) { return -ENOSYS; } /**************************************************************************** * Name: mlx90614_ioctl ****************************************************************************/ static int mlx90614_ioctl(FAR struct file *filep, int cmd, unsigned long arg) { FAR struct inode *inode = filep->f_inode; FAR struct mlx90614_dev_s *priv = inode->i_private; int ret = OK; switch (cmd) { /* Change the device to use a new i2c/smbus address */ case SNIOC_CHANGE_SMBUSADDR: { FAR struct mlx90614_dev_s newdev; FAR uint8_t *ptr = (FAR uint8_t *)((uintptr_t)arg); uint16_t newaddr; uint8_t smbcmd; /* EEPROM reflash only happen when sent at I2C address 0x00 */ newdev.i2c = priv->i2c; newdev.addr = 0x00; /* The I2C address is put in the high byte position */ newaddr = (uint16_t) *ptr; sninfo("Setting new address: 0x%02x\n", newaddr); smbcmd = MLX90614_CMD_EEPROM_ACCESS | MLX90614_SMBUS_ADDR; ret = mlx90614_write_word(&newdev, smbcmd, newaddr); if (ret < 0) { snerr("ERROR: Failed to change the I2C/SMBus address!\n"); } } break; default: snerr("ERROR: Unrecognized cmd: %d\n", cmd); ret = -ENOTTY; break; } return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: mlx90614_register * * Description: * Register the MLX90614 character device as 'devpath' * * Input Parameters: * devpath - The full path to the driver to register. E.g., "/dev/therm0" * i2c - An instance of the I2C interface to use to communicate with * MLX90614 * addr - The I2C address of the MLX90614. * * Returned Value: * Zero (OK) on success; a negated errno value on failure. * ****************************************************************************/ int mlx90614_register(FAR const char *devpath, FAR struct i2c_master_s *i2c, uint8_t addr) { int ret; /* Sanity check */ DEBUGASSERT(i2c != NULL); /* Initialize the MLX90614 device structure */ FAR struct mlx90614_dev_s *priv = (FAR struct mlx90614_dev_s *)kmm_malloc(sizeof(struct mlx90614_dev_s)); if (priv == NULL) { snerr("ERROR: Failed to allocate instance\n"); return -ENOMEM; } priv->i2c = i2c; priv->addr = addr; /* Register the character driver */ ret = register_driver(devpath, &g_mlx90614_fops, 0666, priv); if (ret < 0) { snerr("ERROR: Failed to register driver: %d\n", ret); kmm_free(priv); } return ret; } #endif /* CONFIG_I2C && CONFIG_SENSORS_MLX90614 */