Add support for ENS210/ENS210A/ENS211/ENS212/ENS213A/ENS215. The ENS21x is a family of temperature and relative humidity sensors with accuracies tailored to the needs of specific applications. Signed-off-by: Joshua Felmeden <jfelmeden@xxxxxxxxxxxxxxxxxxxx> --- drivers/iio/humidity/Kconfig | 11 ++ drivers/iio/humidity/Makefile | 1 + drivers/iio/humidity/ens21x.c | 348 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 360 insertions(+) diff --git a/drivers/iio/humidity/Kconfig b/drivers/iio/humidity/Kconfig index b15b7a3b66d5..ff62abf730d1 100644 --- a/drivers/iio/humidity/Kconfig +++ b/drivers/iio/humidity/Kconfig @@ -25,6 +25,17 @@ config DHT11 Other sensors should work as well as long as they speak the same protocol. +config ENS21X + tristate "ENS21X temperature and humidity sensor" + depends on I2C + help + Say yes here to get support for the ScioSense ENS21X family of + humidity and temperature sensors. + + This driver can also be built as a module. If so, the module will be + called ens21x. + + config HDC100X tristate "TI HDC100x relative humidity and temperature sensor" depends on I2C diff --git a/drivers/iio/humidity/Makefile b/drivers/iio/humidity/Makefile index 5fbeef299f61..26590d06d11f 100644 --- a/drivers/iio/humidity/Makefile +++ b/drivers/iio/humidity/Makefile @@ -5,6 +5,7 @@ obj-$(CONFIG_AM2315) += am2315.o obj-$(CONFIG_DHT11) += dht11.o +obj-$(CONFIG_ENS21X) += ens21x.o obj-$(CONFIG_HDC100X) += hdc100x.o obj-$(CONFIG_HDC2010) += hdc2010.o obj-$(CONFIG_HDC3020) += hdc3020.o diff --git a/drivers/iio/humidity/ens21x.c b/drivers/iio/humidity/ens21x.c new file mode 100644 index 000000000000..4145bb117c65 --- /dev/null +++ b/drivers/iio/humidity/ens21x.c @@ -0,0 +1,348 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * ens21x.c - Support for ScioSense ens21x + * temperature & humidity sensor + * + * (7-bit I2C slave address 0x43 ENS210) + * (7-bit I2C slave address 0x43 ENS210A) + * (7-bit I2C slave address 0x44 ENS211) + * (7-bit I2C slave address 0x45 ENS212) + * (7-bit I2C slave address 0x46 ENS213A) + * (7-bit I2C slave address 0x47 ENS215) + * + * Datasheet: + * https://www.sciosense.com/wp-content/uploads/2024/04/ENS21x-Datasheet.pdf + * https://www.sciosense.com/wp-content/uploads/2023/12/ENS210-Datasheet.pdf + */ + +#include <linux/types.h> +#include <linux/i2c.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/crc7.h> + +/* register definitions */ +#define ENS21X_REG_PART_ID 0x00 +#define ENS21X_REG_DIE_REV 0x02 +#define ENS21X_REG_UID 0x04 +#define ENS21X_REG_SYS_CTRL 0x10 +#define ENS21X_REG_SYS_STAT 0x11 +#define ENS21X_REG_SENS_RUN 0x21 +#define ENS21X_REG_SENS_START 0x22 +#define ENS21X_REG_SENS_STOP 0x23 +#define ENS21X_REG_SENS_STAT 0x24 +#define ENS21X_REG_T_VAL 0x30 +#define ENS21X_REG_H_VAL 0x33 + +/* value definitions */ +#define ENS21X_SENS_START_T_START BIT(0) +#define ENS21X_SENS_START_H_START BIT(1) + +#define ENS21X_SENS_STAT_T_ACTIVE BIT(0) +#define ENS21X_SENS_STAT_H_ACTIVE BIT(1) + +#define ENS21X_SYS_CTRL_LOW_POWER_ENABLE BIT(0) +#define ENS21X_SYS_CTRL_SYS_RESET BIT(7) + +#define ENS21X_SYS_STAT_SYS_ACTIVE BIT(0) + +/* magic constants */ +#define ENS21X_CONST_TEMP_SCALE_INT 15 /* integer part of temperature scale (1/64) */ +#define ENS21X_CONST_TEMP_SCALE_DEC 625000 /* decimal part of temperature scale */ +#define ENS21X_CONST_HUM_SCALE_INT 1 /* integer part of humidity scale (1/512) */ +#define ENS21X_CONST_HUM_SCALE_DEC 953125 /* decimal part of humidity scale */ +#define ENS21X_CONST_TEMP_OFFSET_INT -17481 /* temperature offset (64 * -273.15) */ +#define ENS21X_CONST_TEMP_OFFSET_DEC 600000 /* decimal part of offset */ +#define ENS210_CONST_CONVERSION_TIME 130 +#define ENS212_CONST_CONVERSION_TIME 32 +#define ENS215_CONST_CONVERSION_TIME 132 + +static const struct of_device_id ens21x_of_match[]; + +struct ens21x_dev { + struct i2c_client *client; + struct mutex lock; + int part_id; +}; + +enum ens21x_partnumber { + ENS210 = 0x0210, + ENS210A = 0xa210, + ENS211 = 0x0211, + ENS212 = 0x0212, + ENS213A = 0xa213, + ENS215 = 0x0215, +}; + +/* calculate 17-bit crc7 */ +static u8 ens21x_crc7(u32 val) +{ + u32 val_be = (htonl(val & 0x1ffff) >> 0x8); + + return crc7_be(0xde, (u8 *)&val_be, 3) >> 1; +} + +static int ens21x_get_measurement(struct iio_dev *indio_dev, bool temp, int *val) +{ + u32 regval, regval_le; + int ret, tries; + struct ens21x_dev *dev_data = iio_priv(indio_dev); + + /* assert read */ + i2c_smbus_write_byte_data(dev_data->client, ENS21X_REG_SENS_START, + temp ? ENS21X_SENS_START_T_START : + ENS21X_SENS_START_H_START); + + /* wait for conversion to be ready */ + switch (dev_data->part_id) { + case ENS210: + case ENS210A: + msleep(ENS210_CONST_CONVERSION_TIME); + break; + case ENS211: + case ENS212: + msleep(ENS212_CONST_CONVERSION_TIME); + break; + case ENS213A: + case ENS215: + msleep(ENS215_CONST_CONVERSION_TIME); + break; + default: + dev_err(&dev_data->client->dev, "unrecognised device"); + return -ENODEV; + } + + tries = 10; + while (tries-- > 0) { + usleep_range(4000, 5000); + ret = i2c_smbus_read_byte_data(dev_data->client, + ENS21X_REG_SENS_STAT); + if (ret < 0) + continue; + if (!(ret & (temp ? ENS21X_SENS_STAT_T_ACTIVE : + ENS21X_SENS_STAT_H_ACTIVE))) + break; + } + if (tries < 0) { + dev_err(&indio_dev->dev, "timeout waiting for sensor reading\n"); + return -EIO; + } + + /* perform read */ + ret = i2c_smbus_read_i2c_block_data( + dev_data->client, temp ? ENS21X_REG_T_VAL : ENS21X_REG_H_VAL, 3, + (u8 *)®val_le); + if (ret < 0) { + dev_err(&dev_data->client->dev, "failed to read register"); + return -EIO; + } else if (ret == 3) { + regval = le32_to_cpu(regval_le); + if (ens21x_crc7(regval) == ((regval >> 17) & 0x7f)) { + *val = regval & 0xffff; + return IIO_VAL_INT; + } + /* crc fail */ + dev_err(&indio_dev->dev, "ens invalid crc\n"); + return -EIO; + } + + dev_err(&indio_dev->dev, "expected 3 bytes, received %d\n", ret); + return -EIO; +} + +static int ens21x_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *channel, int *val, + int *val2, long mask) +{ + struct ens21x_dev *dev_data = iio_priv(indio_dev); + int ret = -EINVAL; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + mutex_lock(&dev_data->lock); + ret = ens21x_get_measurement( + indio_dev, channel->type == IIO_TEMP, val); + mutex_unlock(&dev_data->lock); + break; + case IIO_CHAN_INFO_SCALE: + if (channel->type == IIO_TEMP) { + *val = ENS21X_CONST_TEMP_SCALE_INT; + *val2 = ENS21X_CONST_TEMP_SCALE_DEC; + } else { + *val = ENS21X_CONST_HUM_SCALE_INT; + *val2 = ENS21X_CONST_HUM_SCALE_DEC; + } + ret = IIO_VAL_INT_PLUS_MICRO; + break; + case IIO_CHAN_INFO_OFFSET: + if (channel->type == IIO_TEMP) { + *val = ENS21X_CONST_TEMP_OFFSET_INT; + *val2 = ENS21X_CONST_TEMP_OFFSET_DEC; + ret = IIO_VAL_INT_PLUS_MICRO; + break; + } + *val = 0; + ret = IIO_VAL_INT; + break; + default: + break; + } + return ret; +} + +static const struct iio_chan_spec ens21x_channels[] = { + /* Temperature channel */ + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OFFSET), + }, + /* Humidity channel */ + { + .type = IIO_HUMIDITYRELATIVE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OFFSET), + } +}; + +static const struct iio_info ens21x_info = { + .read_raw = ens21x_read_raw, +}; + +static const struct i2c_device_id ens21x_id[] = { + {"ens210", ENS210}, + {"ens210a", ENS210A}, + {"ens211", ENS211}, + {"ens212", ENS212}, + {"ens213a", ENS213A}, + {"ens215", ENS215}, + {} +}; +MODULE_DEVICE_TABLE(i2c, ens21x_id); + +static int ens21x_probe(struct i2c_client *client) +{ + const struct i2c_device_id *id = i2c_client_get_device_id(client); + const struct of_device_id *match; + struct ens21x_dev *dev_data; + struct iio_dev *indio_dev; + uint16_t part_id_le, part_id; + int ret, tries; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_WRITE_BYTE_DATA | + I2C_FUNC_SMBUS_WRITE_BYTE | + I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { + dev_err(&client->dev, + "adapter does not support some i2c transactions\n"); + return -EOPNOTSUPP; + } + + match = of_match_device(ens21x_of_match, &client->dev); + if (!match) { + dev_err(&client->dev, "failed to get match data\n"); + return -ENODEV; + } + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data)); + if (!indio_dev) + return -ENOMEM; + + dev_data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + dev_data->client = client; + mutex_init(&dev_data->lock); + + /* reset device */ + ret = i2c_smbus_write_byte_data(client, ENS21X_REG_SYS_CTRL, + ENS21X_SYS_CTRL_SYS_RESET); + if (ret) + return ret; + + /* wait for device to become active */ + usleep_range(4000, 5000); + + /* disable low power mode */ + ret = i2c_smbus_write_byte_data(client, ENS21X_REG_SYS_CTRL, 0x00); + if (ret) + return ret; + + /* wait for device to become active */ + tries = 10; + while (tries-- > 0) { + msleep(20); + ret = i2c_smbus_read_byte_data(client, ENS21X_REG_SYS_STAT); + if (ret < 0) + return ret; + if (ret & ENS21X_SYS_STAT_SYS_ACTIVE) + break; + } + if (tries < 0) { + dev_err(&client->dev, + "timeout waiting for ens21x to become active\n"); + return -EIO; + } + + /* get part_id */ + part_id_le = i2c_smbus_read_word_data(client, ENS21X_REG_PART_ID); + if (part_id_le < 0) + return part_id_le; + part_id = le16_to_cpu(part_id_le); + + if (part_id != id->driver_data) { + dev_err(&client->dev, + "Part ID does not match (0x%04x != 0x%04lx)\n", part_id, + id->driver_data); + return -ENODEV; + } + + /* reenable low power */ + ret = i2c_smbus_write_byte_data(client, ENS21X_REG_SYS_CTRL, + ENS21X_SYS_CTRL_LOW_POWER_ENABLE); + if (ret) + return ret; + + dev_data->part_id = part_id; + + indio_dev->name = id->name; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = ens21x_channels; + indio_dev->num_channels = ARRAY_SIZE(ens21x_channels); + indio_dev->info = &ens21x_info; + + return devm_iio_device_register(&client->dev, indio_dev); +} + + +static const struct of_device_id ens21x_of_match[] = { + { .compatible = "sciosense,ens210" }, + { .compatible = "sciosense,ens210a" }, + { .compatible = "sciosense,ens211" }, + { .compatible = "sciosense,ens212" }, + { .compatible = "sciosense,ens213a" }, + { .compatible = "sciosense,ens215" }, + { }, +}; +MODULE_DEVICE_TABLE(of, ens21x_of_match); + +static struct i2c_driver ens21x_driver = { + .probe = ens21x_probe, + .id_table = ens21x_id, + .driver = { + .name = "ens21x", + .of_match_table = ens21x_of_match, + }, +}; + +module_i2c_driver(ens21x_driver); + +MODULE_DESCRIPTION("ScioSense ENS21x temperature and humidity sensor driver"); +MODULE_AUTHOR("Joshua Felmeden <jfelmeden@xxxxxxxxxxxxxxxxxxxx>"); +MODULE_LICENSE("GPL"); + -- 2.39.2
