/**************************************************************************** * drivers/sensors/sht3x.c * Driver for the Sensirion SHT3x temperature and humidity sensors * * Copyright (C) 2019 Haltian Ltd, Hexagon AB. All rights reserved. * Author: Jussi Kivilinna , * Markus Bernet * * 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_I2C) && defined(CONFIG_SENSORS_SHT3X) /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #ifdef CONFIG_SHT3X_DEBUG # define sht3x_dbg(x, ...) _info(x, ##__VA_ARGS__) #else # define sht3x_dbg(x, ...) sninfo(x, ##__VA_ARGS__) #endif #ifndef CONFIG_SHT3X_I2C_FREQUENCY # define CONFIG_SHT3X_I2C_FREQUENCY 400000 #endif /* Commands */ #define SHT3X_READ_SERIALNBR 0x3780 /* read serial number */ #define SHT3X_READ_STATUS 0xF32D /* read status register */ #define SHT3X_CLEAR_STATUS 0x3041 /* clear status register */ #define SHT3X_HEATER_ENABLE 0x306D /* enabled heater */ #define SHT3X_HEATER_DISABLE 0x3066 /* disable heater */ #define SHT3X_SOFT_RESET 0x30A2 /* soft reset */ #define SHT3X_MEAS_CLOCKSTR_H 0x2C06 /* measurement: clock stretching, high repeatability */ #define SHT3X_MEAS_CLOCKSTR_M 0x2C0D /* measurement: clock stretching, medium repeatability */ #define SHT3X_MEAS_CLOCKSTR_L 0x2C10 /* measurement: clock stretching, low repeatability */ #define SHT3X_MEAS_POLLING_H 0x2400 /* measurement: polling, high repeatability */ #define SHT3X_MEAS_POLLING_M 0x240B /* measurement: polling, medium repeatability */ #define SHT3X_MEAS_POLLING_L 0x2416 /* measurement: polling, low repeatability */ #define SHT3X_MEAS_PERI_05_H 0x2032 /* measurement: periodic 0.5 mps, high repeatability */ #define SHT3X_MEAS_PERI_05_M 0x2024 /* measurement: periodic 0.5 mps, medium repeatability */ #define SHT3X_MEAS_PERI_05_L 0x202F /* measurement: periodic 0.5 mps, low repeatability */ #define SHT3X_MEAS_PERI_1_H 0x2130 /* measurement: periodic 1 mps, high repeatability */ #define SHT3X_MEAS_PERI_1_M 0x2126 /* measurement: periodic 1 mps, medium repeatability */ #define SHT3X_MEAS_PERI_1_L 0x212D /* measurement: periodic 1 mps, low repeatability */ #define SHT3X_MEAS_PERI_2_H 0x2236 /* measurement: periodic 2 mps, high repeatability */ #define SHT3X_MEAS_PERI_2_M 0x2220 /* measurement: periodic 2 mps, medium repeatability */ #define SHT3X_MEAS_PERI_2_L 0x222B /* measurement: periodic 2 mps, low repeatability */ #define SHT3X_MEAS_PERI_4_H 0x2334 /* measurement: periodic 4 mps, high repeatability */ #define SHT3X_MEAS_PERI_4_M 0x2322 /* measurement: periodic 4 mps, medium repeatability */ #define SHT3X_MEAS_PERI_4_L 0x2329 /* measurement: periodic 4 mps, low repeatability */ #define SHT3X_MEAS_PERI_10_H 0x2737 /* measurement: periodic 10 mps, high repeatability */ #define SHT3X_MEAS_PERI_10_M 0x2721 /* measurement: periodic 10 mps, medium repeatability */ #define SHT3X_MEAS_PERI_10_L 0x272A /* measurement: periodic 10 mps, low repeatability */ #define SHT3X_FETCH_DATA 0xE000 /* readout measurements for periodic mode */ #define SHT3X_R_AL_LIM_LS 0xE102 /* read alert limits, low set */ #define SHT3X_R_AL_LIM_LC 0xE109 /* read alert limits, low clear */ #define SHT3X_R_AL_LIM_HS 0xE11F /* read alert limits, high set */ #define SHT3X_R_AL_LIM_HC 0xE114 /* read alert limits, high clear */ #define SHT3X_W_AL_LIM_HS 0x611D /* write alert limits, high set */ #define SHT3X_W_AL_LIM_HC 0x6116 /* write alert limits, high clear */ #define SHT3X_W_AL_LIM_LC 0x610B /* write alert limits, low clear */ #define SHT3X_W_AL_LIM_LS 0x6100 /* write alert limits, low set */ #define SHT3X_NO_SLEEP 0x303E /* disable sleep */ #define SHT3X_DEFAULT_MEAS_MODE SHT3X_MEAS_PERI_1_H /**************************************************************************** * Private ****************************************************************************/ struct sht3x_dev_s { FAR struct i2c_master_s *i2c; /* I2C interface */ uint8_t addr; /* I2C address */ bool valid; /* If cached readings are valid */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS bool unlinked; /* True, driver has been unlinked */ #endif struct timespec last_update; /* Last time when sensor was read */ struct sht3x_meas_data_s data; /* Cached sensor values */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS int16_t crefs; /* Number of open references */ #endif sem_t devsem; }; struct sht3x_word_s { uint8_t data[2]; uint8_t crc; }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ /* I2C Helpers */ static int sht3x_do_transfer(FAR struct i2c_master_s *i2c, FAR struct i2c_msg_s *msgv, size_t nmsg); static int sht3x_write_cmd(FAR struct sht3x_dev_s *priv, uint16_t cmd, FAR struct sht3x_word_s *params, unsigned int num_params); static int sht3x_read_cmd(FAR struct sht3x_dev_s *priv, uint16_t cmd, FAR struct sht3x_word_s *words, unsigned int num_words); /* Character driver methods */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int sht3x_open(FAR struct file *filep); static int sht3x_close(FAR struct file *filep); #endif static ssize_t sht3x_read(FAR struct file *filep, FAR char *buffer, size_t buflen); static ssize_t sht3x_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); static int sht3x_ioctl(FAR struct file *filep, int cmd, unsigned long arg); #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int sht3x_unlink(FAR struct inode *inode); #endif /**************************************************************************** * Private Data ****************************************************************************/ static const struct file_operations g_sht3xfops = { #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS sht3x_open, /* open */ sht3x_close, /* close */ #else NULL, /* open */ NULL, /* close */ #endif sht3x_read, /* read */ sht3x_write, /* write */ NULL, /* seek */ sht3x_ioctl /* ioctl */ #ifndef CONFIG_DISABLE_POLL , NULL /* poll */ #endif #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS , sht3x_unlink /* unlink */ #endif }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: sht3x_do_transfer ****************************************************************************/ static int sht3x_do_transfer(FAR struct i2c_master_s *i2c, FAR struct i2c_msg_s *msgv, size_t nmsg) { int ret = ret = I2C_TRANSFER(i2c, msgv, nmsg); if (ret >= 0) { return OK; } sht3x_dbg("transfer failed: %d\n", ret); return ret; } /**************************************************************************** * Name: sht3x_write_cmd ****************************************************************************/ static int sht3x_write_cmd(FAR struct sht3x_dev_s *priv, uint16_t cmd, FAR struct sht3x_word_s *params, unsigned int num_params) { struct i2c_msg_s msg[2]; uint8_t cmd_buf[2]; int ret; cmd_buf[0] = cmd >> 8; cmd_buf[1] = cmd >> 0; msg[0].frequency = CONFIG_SHT3X_I2C_FREQUENCY; msg[0].addr = priv->addr; msg[0].flags = 0; msg[0].buffer = cmd_buf; msg[0].length = 2; if (num_params) { msg[1].frequency = CONFIG_SHT3X_I2C_FREQUENCY; msg[1].addr = priv->addr; msg[1].flags = I2C_M_NOSTART; msg[1].buffer = (FAR uint8_t *)params; msg[1].length = num_params * sizeof(*params); } ret = sht3x_do_transfer(priv->i2c, msg, (num_params) ? 2 : 1); sht3x_dbg("cmd: 0x%04X num_params: %d ret: %d\n", cmd, num_params, ret); return (ret >= 0) ? OK : ret; } /**************************************************************************** * Name: sht3x_read_cmd ****************************************************************************/ static int sht3x_read_cmd(FAR struct sht3x_dev_s *priv, uint16_t cmd, FAR struct sht3x_word_s *words, unsigned int num_words) { struct i2c_msg_s msg[1]; uint8_t addr_buf[2]; int ret; addr_buf[0] = cmd >> 8; addr_buf[1] = cmd >> 0; msg[0].frequency = CONFIG_SHT3X_I2C_FREQUENCY; msg[0].addr = priv->addr; msg[0].flags = 0; msg[0].buffer = addr_buf; msg[0].length = 2; ret = sht3x_do_transfer(priv->i2c, msg, 1); sht3x_dbg("cmd: 0x%04X ret: %d\n", cmd, ret); if (ret < 0) { return ret; } msg[0].frequency = CONFIG_SHT3X_I2C_FREQUENCY; msg[0].addr = priv->addr; msg[0].flags = I2C_M_READ; msg[0].buffer = (FAR uint8_t *)words; msg[0].length = num_words * sizeof(*words); ret = sht3x_do_transfer(priv->i2c, msg, 1); sht3x_dbg("read cmd: 0x%04X num_params: %d ret: %d\n", cmd, num_words, ret); return (ret >= 0) ? OK : ret; } /**************************************************************************** * Name: sht3x_crc_word ****************************************************************************/ static uint8_t sht3x_crc_word(uint16_t word) { static const uint8_t crc_table[16] = { 0x00, 0x31, 0x62, 0x53, 0xc4, 0xf5, 0xa6, 0x97, 0xb9, 0x88, 0xdb, 0xea, 0x7d, 0x4c, 0x1f, 0x2e }; uint8_t crc = 0xff; crc ^= word >> 8; crc = (crc << 4) ^ crc_table[crc >> 4]; crc = (crc << 4) ^ crc_table[crc >> 4]; crc ^= word >> 0; crc = (crc << 4) ^ crc_table[crc >> 4]; crc = (crc << 4) ^ crc_table[crc >> 4]; return crc; } /**************************************************************************** * Name: sht3x_data_word2uint16 ****************************************************************************/ static uint16_t sht3x_data_word2uint16(FAR const struct sht3x_word_s *word) { return (word[0].data[0] << 8) | (word[0].data[1]); } /**************************************************************************** * Name: sht3x_check_data_crc ****************************************************************************/ static int sht3x_check_data_crc(FAR const struct sht3x_word_s *words, unsigned int num_words) { while (num_words) { if (sht3x_crc_word(sht3x_data_word2uint16(words)) != words->crc) { return -1; } num_words--; words++; } return 0; } /**************************************************************************** * Name: sht3x_softreset * * Description: * Reset the SHT3x sensor. * ****************************************************************************/ static inline int sht3x_softreset(FAR struct sht3x_dev_s *priv) { return sht3x_write_cmd(priv, SHT3X_SOFT_RESET, NULL, 0); } /**************************************************************************** * Name: sht3x_temp_to_celsius * * Description: * Convert raw temperature value to degrees Celsius. * ****************************************************************************/ static inline float sht3x_temp_to_celsius(uint16_t raw) { /* Calculate temperature [°C] * T = -45 + 175 * rawValue / (2^16-1) */ return 175.0f * (float)raw / 65535.0f - 45.0f; } /**************************************************************************** * Name: sht3x_rh_to_percent * * Description: * Convert raw humidity value to relative humidity [%]. * ****************************************************************************/ static inline float sht3x_rh_to_percent(uint16_t raw) { /* Calculate relative humidity [%RH] * RH = rawValue / (2^16-1) * 100 */ return 100.0f * (float)raw / 65535.0f; } /**************************************************************************** * Name: sht3x_read_values ****************************************************************************/ static int sht3x_read_values(FAR struct sht3x_dev_s *priv, FAR struct sht3x_meas_data_s *out) { struct sht3x_word_s data[2]; uint16_t temp16; uint16_t rh16; struct timespec ts; int ret; clock_gettime(CLOCK_REALTIME, &ts); /* Read the raw data */ ret = sht3x_read_cmd(priv, SHT3X_FETCH_DATA, data, 2); if (ret < 0) { sht3x_dbg("ERROR: sht3x_read_cmd failed: %d\n", ret); return ret; } if (sht3x_check_data_crc(data, 2) < 0) { sht3x_dbg("ERROR: sht3x_read_values crc failed\n"); ret = -EIO; return ret; } temp16 = sht3x_data_word2uint16(data); rh16 = sht3x_data_word2uint16(&data[1]); add_sensor_randomness(ts.tv_nsec ^ ((int)temp16 << 16 | rh16)); priv->data.temperature = sht3x_temp_to_celsius(temp16); priv->data.humidity = sht3x_rh_to_percent(rh16); priv->last_update = ts; priv->valid = true; *out = priv->data; return OK; } /**************************************************************************** * Name: sht3x_open * * Description: * This function is called whenever the SHT3x device is opened. * ****************************************************************************/ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int sht3x_open(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct sht3x_dev_s *priv = inode->i_private; int ret; /* Get exclusive access */ ret = nxsem_wait_uninterruptible(&priv->devsem); if (ret < 0) { return ret; } /* Increment the count of open references on the driver */ priv->crefs++; DEBUGASSERT(priv->crefs > 0); nxsem_post(&priv->devsem); return OK; } #endif /**************************************************************************** * Name: sht3x_close * * Description: * This routine is called when the SHT3x device is closed. * ****************************************************************************/ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int sht3x_close(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct sht3x_dev_s *priv = inode->i_private; int ret; /* Get exclusive access */ ret = nxsem_wait_uninterruptible(&priv->devsem); if (ret < 0) { return ret; } /* Decrement the count of open references on the driver */ DEBUGASSERT(priv->crefs > 0); priv->crefs--; /* If the count has decremented to zero and the driver has been unlinked, * then free memory now. */ if (priv->crefs <= 0 && priv->unlinked) { nxsem_destroy(&priv->devsem); kmm_free(priv); return OK; } nxsem_post(&priv->devsem); return OK; } #endif /**************************************************************************** * Name: sht3x_read ****************************************************************************/ static ssize_t sht3x_read(FAR struct file *filep, FAR char *buffer, size_t buflen) { /* Use ioctl to read from sensor */ return -ENOSYS; } /**************************************************************************** * Name: sht3x_write ****************************************************************************/ static ssize_t sht3x_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) { return -ENOSYS; } /**************************************************************************** * Name: sht3x_ioctl ****************************************************************************/ static int sht3x_ioctl(FAR struct file *filep, int cmd, unsigned long arg) { FAR struct inode *inode = filep->f_inode; FAR struct sht3x_dev_s *priv = inode->i_private; int ret; /* Get exclusive access */ ret = nxsem_wait_uninterruptible(&priv->devsem); if (ret < 0) { return ret; } #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS if (priv->unlinked) { /* Do not allow operations on unlinked sensors. This allows * sensor use on hot swappable I2C bus. */ nxsem_post(&priv->devsem); return -ENODEV; } #endif switch (cmd) { /* Soft reset the SHT3x, Arg: None */ case SNIOC_RESET: { ret = sht3x_softreset(priv); sht3x_dbg("softreset ret: %d\n", ret); } break; /* Start periodic measurement mode, Arg: None */ case SNIOC_START: { ret = sht3x_write_cmd(priv, SHT3X_DEFAULT_MEAS_MODE, NULL, 0); if (ret < 0) { sht3x_dbg("cannot start periodic measurement mode: %d\n", ret); } } break; case SNIOC_READ_CONVERT_DATA: { FAR struct sht3x_meas_data_s *data = (FAR struct sht3x_meas_data_s *)arg; ret = sht3x_read_values(priv, data); if (ret < 0) { sht3x_dbg("cannot read data: %d\n", ret); } } break; default: sht3x_dbg("Unrecognized cmd: %d\n", cmd); ret = -ENOTTY; break; } nxsem_post(&priv->devsem); return ret; } /**************************************************************************** * Name: sht3x_unlink ****************************************************************************/ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int sht3x_unlink(FAR struct inode *inode) { FAR struct sht3x_dev_s *priv; int ret; DEBUGASSERT(inode != NULL && inode->i_private != NULL); priv = (FAR struct sht3x_dev_s *)inode->i_private; /* Get exclusive access */ ret = nxsem_wait_uninterruptible(&priv->devsem); if (ret < 0) { return ret; } /* Are there open references to the driver data structure? */ if (priv->crefs <= 0) { nxsem_destroy(&priv->devsem); kmm_free(priv); return OK; } /* No... just mark the driver as unlinked and free the resources when * the last client closes their reference to the driver. */ priv->unlinked = true; nxsem_post(&priv->devsem); return OK; } #endif /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: sht3x_register * * Description: * Register the SHT3x character device as 'devpath' * * Input Parameters: * devpath - The full path to the driver to register. E.g., "/dev/temp0" * i2c - An instance of the I2C interface to use to communicate with * the SHT3x * addr - The I2C address of the SHT3x. * * Returned Value: * Zero (OK) on success; a negated errno value on failure. * ****************************************************************************/ int sht3x_register(FAR const char *devpath, FAR struct i2c_master_s *i2c, uint8_t addr) { FAR struct sht3x_dev_s *priv; int ret; DEBUGASSERT(i2c != NULL); /* Initialize the device structure */ priv = (FAR struct sht3x_dev_s *)kmm_zalloc(sizeof(struct sht3x_dev_s)); if (priv == NULL) { snerr("ERROR: Failed to allocate instance\n"); return -ENOMEM; } priv->i2c = i2c; priv->addr = addr; nxsem_init(&priv->devsem, 0, 1); /* Register the character driver */ ret = register_driver(devpath, &g_sht3xfops, 0666, priv); if (ret < 0) { snerr("ERROR: Failed to register driver: %d\n", ret); kmm_free(priv); } return ret; } #endif /* CONFIG_I2C && CONFIG_SENSORS_SHT3X */