/**************************************************************************** * drivers/sensors/hdc1008.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 #include #if defined(CONFIG_I2C) && defined(CONFIG_SENSORS_HDC1008) /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #ifdef CONFIG_HDC1008_DEBUG # define hdc1008_dbg(x, ...) _info(x, ##__VA_ARGS__) #else # define hdc1008_dbg(x, ...) sninfo(x, ##__VA_ARGS__) #endif #ifndef CONFIG_SHT21_I2C_FREQUENCY # define CONFIG_SHT21_I2C_FREQUENCY 400000 #endif /* Macros to convert raw temperature and humidity to real values. Temperature * is scaled by 100, humidity by 10. */ #define RAW_TO_TEMP(x) (((x) * 16500 / 65536) - 4000) #define RAW_TO_RH(x) ((x) * 1000 / 65536) /* Resolution for measurements. 8-bit is only valid for humidity. */ #define CONFIGURATION_RES_14BIT 0x00 #define CONFIGURATION_RES_11BIT 0x01 #define CONFIGURATION_RES_8BIT 0x02 /* HDC1008 registers */ #define HDC1008_REG_TEMPERATURE 0x00 #define HDC1008_REG_HUMIDITY 0x01 #define HDC1008_REG_CONFIGURATION 0x02 #define HDC1008_REG_SERIALID_0 0xFB /* Bits 0-15: Bit 24-39 of serial */ #define HDC1008_REG_SERIALID_1 0xFC /* Bits 0-15: Bit 8-23 of serial */ #define HDC1008_REG_SERIALID_2 0xFD /* Bits 7-15: Bit 0-7 of serial */ /* Configuration register bits */ #define HDC1008_CONFIGURATION_HRES_SHIFT (8) /* Bits 8-9: Humidity resolution */ #define HDC1008_CONFIGURATION_HRES_MASK (0x03 << HDC1008_CONFIGURATION_HRES_SHIFT) # define HDC1008_CONFIGURATION_HRES_14BIT (CONFIGURATION_RES_14BIT << HDC1008_CONFIGURATION_HRES_SHIFT) # define HDC1008_CONFIGURATION_HRES_11BIT (CONFIGURATION_RES_11BIT << HDC1008_CONFIGURATION_HRES_SHIFT) # define HDC1008_CONFIGURATION_HRES_8BIT (CONFIGURATION_RES_8BIT << HDC1008_CONFIGURATION_HRES_SHIFT) #define HDC1008_CONFIGURATION_TRES_SHIFT (10) /* Bit 10: Temperature resolution */ #define HDC1008_CONFIGURATION_TRES_MASK (0x01 << HDC1008_CONFIGURATION_TRES_SHIFT) # define HDC1008_CONFIGURATION_TRES_14BIT (CONFIGURATION_RES_14BIT << HDC1008_CONFIGURATION_TRES_SHIFT) # define HDC1008_CONFIGURATION_TRES_11BIT (CONFIGURATION_RES_11BIT << HDC1008_CONFIGURATION_TRES_SHIFT) #define HDC1008_CONFIGURATION_BTST (1 << 11) /* Bit 11: Battery status */ #define HDC1008_CONFIGURATION_MODE (1 << 12) /* Bit 12: Mode of acquisition */ #define HDC1008_CONFIGURATION_HEAT_SHIFT (13) /* Bit 13: Heater */ #define HDC1008_CONFIGURATION_HEAT_MASK (0x01 << HDC1008_CONFIGURATION_HEAT_SHIFT) # define HDC1008_CONFIGURATION_HEAT_DISABLE (0x00 << HDC1008_CONFIGURATION_HEAT_SHIFT) # define HDC1008_CONFIGURATION_HEAT_ENABLE (0x01 << HDC1008_CONFIGURATION_HEAT_SHIFT) /* Bit 14: Reserved */ #define HDC1008_CONFIGURATION_RST (1 << 15) /* Bit 15: Software reset bit */ /**************************************************************************** * Private ****************************************************************************/ struct hdc1008_dev_s { FAR struct i2c_master_s *i2c; /* I2C interface */ uint8_t addr; /* I2C address */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS bool unlinked; /* True, driver has been unlinked */ #endif uint8_t mode; /* Acquisition mode */ uint16_t configuration; /* Configuration shadow register */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS int16_t crefs; /* Number of open references */ #endif sem_t devsem; }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ /* Character driver methods */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int hdc1008_open(FAR struct file *filep); static int hdc1008_close(FAR struct file *filep); #endif static ssize_t hdc1008_read(FAR struct file *filep, FAR char *buffer, size_t buflen); static ssize_t hdc1008_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); static int hdc1008_ioctl(FAR struct file *filep, int cmd, unsigned long arg); #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int hdc1008_unlink(FAR struct inode *inode); #endif static int hdc1008_getreg(FAR struct hdc1008_dev_s *priv, uint8_t regaddr, FAR uint16_t *regval); static int hdc1008_putreg(FAR struct hdc1008_dev_s *priv, uint8_t regaddr, FAR uint16_t regval); static int hdc1008_reset(FAR struct hdc1008_dev_s *priv); static int hdc1008_measure_trh(FAR struct hdc1008_dev_s *priv, int *t, int *h); static int hdc1008_measure_current_mode(struct hdc1008_dev_s *priv, struct hdc1008_conv_data_s *data); /**************************************************************************** * Private Data ****************************************************************************/ static const struct file_operations g_hdc1008fops = { #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS hdc1008_open, /* open */ hdc1008_close, /* close */ #else NULL, /* open */ NULL, /* close */ #endif hdc1008_read, /* read */ hdc1008_write, /* write */ NULL, /* seek */ hdc1008_ioctl, /* ioctl */ NULL /* poll */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS , hdc1008_unlink /* unlink */ #endif }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: hdc1008_measure_trh * * Description: * Read both temperature and humidity from the sensor * ****************************************************************************/ static int hdc1008_measure_trh(FAR struct hdc1008_dev_s *priv, int *t, int *h) { struct i2c_config_s config; uint8_t buf[4]; uint8_t reg = HDC1008_REG_TEMPERATURE; int tmp; int ret; config.frequency = CONFIG_HDC1008_I2C_FREQUENCY; config.address = priv->addr; config.addrlen = 7; ret = i2c_write(priv->i2c, &config, ®, 1); /* Wait for measurement to complete. Max should be about 20 ms if measuring * both temperature and humidity. */ nxsig_usleep(20000); ret = i2c_read(priv->i2c, &config, buf, 4); if (ret < 0) { return ret; } /* Convert raw data from sensor to temperature/humidity */ tmp = ((int)buf[0] << 8) | (int)buf[1]; tmp = RAW_TO_TEMP(tmp); *t = tmp; tmp = ((int)buf[2] << 8) | (int)buf[3]; tmp = RAW_TO_RH(tmp); *h = tmp; return 0; } /**************************************************************************** * Name: hdc1008_measure_t_or_rh * * Description: * Read both temperature and humidity from the sensor * ****************************************************************************/ static int hdc1008_measure_t_or_rh(FAR struct hdc1008_dev_s *priv, bool temperature, int *val) { struct i2c_config_s config; uint8_t buf[4]; uint8_t reg; int tmp; int ret; config.frequency = CONFIG_HDC1008_I2C_FREQUENCY; config.address = priv->addr; config.addrlen = 7; reg = temperature ? HDC1008_REG_TEMPERATURE : HDC1008_REG_HUMIDITY; ret = i2c_write(priv->i2c, &config, ®, 1); /* Wait for measurement to complete. 10 ms wait should give enough * margin for either temperature/humidity at maximum resolution. */ nxsig_usleep(10000); ret = i2c_read(priv->i2c, &config, buf, 2); if (ret < 0) { return ret; } /* Convert raw data from sensor to temperature/humidity */ tmp = ((int)buf[0] << 8) | (int)buf[1]; tmp = temperature ? RAW_TO_TEMP(tmp) : RAW_TO_RH(tmp); *val = tmp; return 0; } /**************************************************************************** * Name: hdc1008_set_operational_mode * * Description: * Configure the HDC1008 for measuring humitidy, temperature or both. * ****************************************************************************/ static int hdc1008_set_operational_mode(struct hdc1008_dev_s *priv, uint8_t mode) { int ret; uint16_t reg; ret = hdc1008_getreg(priv, HDC1008_REG_CONFIGURATION, ®); if (ret < 0) { return ret; } switch (mode) { case HDC1008_MEAS_TEMPERATURE: { reg &= ~HDC1008_CONFIGURATION_MODE; break; } case HDC1008_MEAS_HUMIDITY: { reg &= ~HDC1008_CONFIGURATION_MODE; break; } case HDC1008_MEAS_T_AND_RH: { reg |= HDC1008_CONFIGURATION_MODE; break; } default: return -EINVAL; } priv->mode = mode; return hdc1008_putreg(priv, HDC1008_REG_CONFIGURATION, reg); } /**************************************************************************** * Name: hdc1008_set_temperature_resolution * * Description: * Configure the HDC1008 temperature resolution * ****************************************************************************/ static int hdc1008_set_temperature_resolution(struct hdc1008_dev_s *priv, uint8_t resolution) { int ret; uint16_t reg; ret = hdc1008_getreg(priv, HDC1008_REG_CONFIGURATION, ®); if (ret < 0) { return ret; } reg &= ~HDC1008_CONFIGURATION_TRES_MASK; switch (resolution) { case 11: { reg |= HDC1008_CONFIGURATION_TRES_11BIT; break; } case 14: { reg |= HDC1008_CONFIGURATION_TRES_14BIT; break; } default: return -EINVAL; } return hdc1008_putreg(priv, HDC1008_REG_CONFIGURATION, reg); } /**************************************************************************** * Name: hdc1008_set_humidity_resolution * * Description: * Configure the HDC1008 humidity resolution * ****************************************************************************/ static int hdc1008_set_humidity_resolution(struct hdc1008_dev_s *priv, uint8_t resolution) { int ret; uint16_t reg; ret = hdc1008_getreg(priv, HDC1008_REG_CONFIGURATION, ®); if (ret < 0) { return ret; } reg &= ~HDC1008_CONFIGURATION_HRES_MASK; switch (resolution) { case 8: { reg |= HDC1008_CONFIGURATION_HRES_8BIT; break; } case 11: { reg |= HDC1008_CONFIGURATION_HRES_11BIT; break; } case 14: { reg |= HDC1008_CONFIGURATION_HRES_14BIT; break; } default: return -EINVAL; } return hdc1008_putreg(priv, HDC1008_REG_CONFIGURATION, reg); } /**************************************************************************** * Name: hdc1008_set_heater_mode * * Description: * Configure the HDC1008 heater mode * ****************************************************************************/ static int hdc1008_set_heater_mode(struct hdc1008_dev_s *priv, uint8_t mode) { int ret; uint16_t reg; ret = hdc1008_getreg(priv, HDC1008_REG_CONFIGURATION, ®); if (ret < 0) { return ret; } reg &= ~HDC1008_CONFIGURATION_HEAT_MASK; if (mode == 0) { reg |= HDC1008_CONFIGURATION_HEAT_DISABLE; } else if (mode == 1) { reg |= HDC1008_CONFIGURATION_HEAT_ENABLE; } else { return -EINVAL; } return hdc1008_putreg(priv, HDC1008_REG_CONFIGURATION, reg); } /**************************************************************************** * Name: hdc1008_getreg * * Description: * Get value of 16-bit register * ****************************************************************************/ static int hdc1008_getreg(FAR struct hdc1008_dev_s *priv, uint8_t regaddr, FAR uint16_t *regval) { int ret; struct i2c_config_s config; uint8_t buf[2]; config.frequency = CONFIG_HDC1008_I2C_FREQUENCY; config.address = priv->addr; config.addrlen = 7; ret = i2c_write(priv->i2c, &config, ®addr, 1); if (ret < 0) { return ret; } ret = i2c_read(priv->i2c, &config, buf, 2); if (ret < 0) { return ret; } *regval = (buf[0] << 8) | buf[1]; return ret; } /**************************************************************************** * Name: hdc1008_putreg * * Description: * Set value of 16-bit register * ****************************************************************************/ static int hdc1008_putreg(FAR struct hdc1008_dev_s *priv, uint8_t regaddr, FAR uint16_t regval) { struct i2c_config_s config; uint8_t buf[3]; config.frequency = CONFIG_HDC1008_I2C_FREQUENCY; config.address = priv->addr; config.addrlen = 7; hdc1008_dbg("addr=%02x; reg=%02x; val=%04x\n", priv->addr, regaddr, regval); buf[0] = regaddr; buf[1] = (uint8_t)((regval >> 8) & 0xff); buf[2] = (uint8_t)(regval & 0xff); return i2c_write(priv->i2c, &config, buf, 3); } /**************************************************************************** * Name: hdc1008_open * * Description: * This function is called whenever the hdc1008 device is opened. * ****************************************************************************/ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int hdc1008_open(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct hdc1008_dev_s *priv = (FAR struct hdc1008_dev_s *)inode->i_private; int ret; ret = nxsem_wait_uninterruptible(&priv->devsem); if (ret < 0) { return ret; } /* Increases the reference count */ ++priv->crefs; DEBUGASSERT(priv->crefs > 0); nxsem_post(&priv->devsem); return 0; } #endif /**************************************************************************** * Name: hdc1008_close * * Description: * This routine is called when the hdc1008 device is closed. * ****************************************************************************/ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int hdc1008_close(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct hdc1008_dev_s *priv = (FAR struct hdc1008_dev_s *)inode->i_private; int ret; ret = nxsem_wait_uninterruptible(&priv->devsem); if (ret < 0) { return ret; } /* Decrement the reference count */ DEBUGASSERT(priv->crefs > 0); --priv->crefs; /* If the reference count is zero, and the driver has been unlinked, free * the memory. */ if ((priv->crefs <= 0) && priv->unlinked) { nxsem_destroy(&priv->devsem); kmm_free(priv); return OK; } nxsem_post(&priv->devsem); return OK; } #endif /**************************************************************************** * Name: hdc1008_read * * Description: * Called when the driver is read from. * ****************************************************************************/ static ssize_t hdc1008_read(FAR struct file *filep, FAR char *buffer, size_t buflen) { FAR struct inode *inode = filep->f_inode; FAR struct hdc1008_dev_s *priv = (FAR struct hdc1008_dev_s *)inode->i_private; int ret; int len = 0; struct hdc1008_conv_data_s data; DEBUGASSERT(filep != NULL); /* Sanity check of input buffer argument */ if (buffer == NULL) { return -EINVAL; } /* Get exclusive access */ ret = nxsem_wait_uninterruptible(&priv->devsem); if (ret < 0) { return (ssize_t)ret; } #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS if (priv->unlinked) { /* The driver is unliked, access is not allowed */ nxsem_post(&priv->devsem); return -ENODEV; } #endif ret = hdc1008_measure_current_mode(priv, &data); if (ret < 0) { nxsem_post(&priv->devsem); return ret; } if (priv->mode == HDC1008_MEAS_TEMPERATURE) { len = snprintf(buffer, buflen, "%d.%02d", data.temperature / 100, data.temperature % 100); } else if (priv->mode == HDC1008_MEAS_HUMIDITY) { len = snprintf(buffer, buflen, "%d.%d", data.humidity / 10, data.humidity % 10); } else if (priv->mode == HDC1008_MEAS_T_AND_RH) { len = snprintf(buffer, buflen, "%d.%02d %d.%d", data.temperature / 100, data.temperature % 100, data.humidity / 10, data.humidity % 10); } else { nxsem_post(&priv->devsem); return -EINVAL; } nxsem_post(&priv->devsem); return len; } /**************************************************************************** * Name: hdc1008_measure_current_mode * * Description: * Measure from sensor according to current mode (temperature, humidity or * both). * ****************************************************************************/ static int hdc1008_measure_current_mode(struct hdc1008_dev_s *priv, struct hdc1008_conv_data_s *data) { int ret; int temperature; int humidity; switch (priv->mode) { case HDC1008_MEAS_TEMPERATURE: ret = hdc1008_measure_t_or_rh(priv, true, &temperature); if (ret < 0) { return ret; } data->temperature = temperature; break; case HDC1008_MEAS_HUMIDITY: ret = hdc1008_measure_t_or_rh(priv, false, &humidity); if (ret < 0) { return ret; } data->humidity = humidity; break; case HDC1008_MEAS_T_AND_RH: ret = hdc1008_measure_trh(priv, &temperature, &humidity); if (ret < 0) { return ret; } data->temperature = temperature; data->humidity = humidity; break; default: ret = -EINVAL; break; } return ret; } /**************************************************************************** * Name: hdc1008_write * * Description: * Called when the driver is written to (not supported). * ****************************************************************************/ static ssize_t hdc1008_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) { return -ENOSYS; } /**************************************************************************** * Name: hdc1008_ioctl * * Description: * Called when an ioctl() operation is made for the driver. * ****************************************************************************/ static int hdc1008_ioctl(FAR struct file *filep, int cmd, unsigned long arg) { FAR struct inode *inode = filep->f_inode; FAR struct hdc1008_dev_s *priv = (FAR struct hdc1008_dev_s *)inode->i_private; int ret; /* Get exclusive access */ ret = nxsem_wait_uninterruptible(&priv->devsem); if (ret < 0) { return (ssize_t)ret; } #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS if (priv->unlinked) { /* The driver is unliked, access is not allowed */ nxsem_post(&priv->devsem); return -ENODEV; } #endif switch (cmd) { case SNIOC_RESET: { ret = hdc1008_reset(priv); hdc1008_dbg("reset ret: %d\n", ret); break; } case SNIOC_SET_OPERATIONAL_MODE: { ret = hdc1008_set_operational_mode(priv, (uint8_t)arg); hdc1008_dbg("opmode ret: %d\n", ret); break; } case SNIOC_SET_RESOLUTION_T: { ret = hdc1008_set_temperature_resolution(priv, (uint8_t)arg); hdc1008_dbg("tres ret: %d\n", ret); break; } case SNIOC_SET_RESOLUTION_RH: { ret = hdc1008_set_humidity_resolution(priv, (uint8_t)arg); hdc1008_dbg("hres ret: %d\n", ret); break; } case SNIOC_SET_HEATER_MODE: { ret = hdc1008_set_heater_mode(priv, (uint8_t)arg); hdc1008_dbg("heater ret: %d\n", ret); break; } case SNIOC_GET_CONFIGURATION: { uint16_t reg; ret = hdc1008_getreg(priv, HDC1008_REG_CONFIGURATION, ®); if (ret >= 0) { *(uint16_t *)arg = reg; } hdc1008_dbg("read config ret: %d\n", ret); break; } case SNIOC_MEASURE: { struct hdc1008_conv_data_s data; ret = hdc1008_measure_current_mode(priv, &data); if (ret >= 0) memcpy((struct hdc1008_conv_data_s *)arg, &data, sizeof(data)); break; } default: { hdc1008_dbg("unrecognized cmd: %d\n", cmd); _info("unknown cmd: %d\n", cmd); ret = -ENOTTY; break; } } nxsem_post(&priv->devsem); return ret; } /**************************************************************************** * Name: hdc1008_unlink * * Description: * Called when the driver is unlinked. * ****************************************************************************/ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int hdc1008_unlink(FAR struct inode *inode) { FAR struct hdc1008_dev_s *priv; int ret; DEBUGASSERT((inode != NULL) && (inode->i_private != NULL)); priv = (FAR struct hdc1008_dev_s *)inode->i_private; ret = nxsem_wait_uninterruptible(&priv->devsem); if (ret < 0) { return ret; } /* Are there any open references to the driver? */ if (priv->crefs <= 0) { nxsem_destroy(&priv->devsem); kmm_free(priv); return OK; } /* We still have open references, mark driver as unliked and wait for * everyone to close their instance. */ priv->unlinked = true; nxsem_post(&priv->devsem); return OK; } #endif /**************************************************************************** * Name: hdc1008_reset * * Description: * Perform a software reset of the sensor * ****************************************************************************/ static int hdc1008_reset(FAR struct hdc1008_dev_s *priv) { int ret; int count = 10; uint16_t reg; ret = hdc1008_getreg(priv, HDC1008_REG_CONFIGURATION, ®); if (ret < 0) { return ret; } ret = hdc1008_putreg(priv, HDC1008_REG_CONFIGURATION, reg | HDC1008_CONFIGURATION_RST); if (ret < 0) { return ret; } /* Now we wait until the sensor has reset */ do { ret = hdc1008_getreg(priv, HDC1008_REG_CONFIGURATION, ®); nxsig_usleep(1000); --count; } while ((reg & HDC1008_CONFIGURATION_RST) && (ret == OK) && count); return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: hdc1008_register * * Description: * Register the HDC1008 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 HDC1008 * addr - The I2C address of the HDC1008. The I2C address is * configurable by two address pins, in the range of 0x40-0x43 * * Returned Value: * Zero (OK) on success; a negated errno value on failure. * ****************************************************************************/ int hdc1008_register(FAR const char *devpath, FAR struct i2c_master_s *i2c, uint8_t addr) { FAR struct hdc1008_dev_s *priv; uint16_t reg; int ret; DEBUGASSERT(i2c != NULL); /* Initialize the driver structure */ priv = (FAR struct hdc1008_dev_s *)kmm_zalloc(sizeof(struct hdc1008_dev_s)); if (priv == NULL) { snerr("ERROR: Failed to allocate memory for driver data\n"); return -ENOMEM; } priv->i2c = i2c; priv->addr = addr; nxsem_init(&priv->devsem, 0, 1); /* Register the driver */ ret = register_driver(devpath, &g_hdc1008fops, 0666, priv); if (ret < 0) { snerr("ERROR: Failed to register driver: %d\n", ret); nxsem_destroy(&priv->devsem); kmm_free(priv); } sninfo("driver registered\n"); /* 15 ms max startup time according to datasheet, let's wait just to be * sure that it is ready. */ nxsig_usleep(15000); /* Set default configuration */ ret = hdc1008_getreg(priv, HDC1008_REG_CONFIGURATION, ®); if (ret < 0) { snerr("ERROR: failed to read default configuration\n"); nxsem_destroy(&priv->devsem); kmm_free(priv); return ret; } /* Enforce sensor default configuration at startup */ reg = HDC1008_CONFIGURATION_MODE; ret = hdc1008_putreg(priv, HDC1008_REG_CONFIGURATION, reg); if (ret < 0) { snerr("ERROR: failed to set default configuration: %d\n", ret); nxsem_destroy(&priv->devsem); kmm_free(priv); return ret; } priv->mode = HDC1008_MEAS_T_AND_RH; return ret; } #endif /* CONFIG_I2C && CONFIG_SENSORS_HDC1008 */