diff options
Diffstat (limited to 'drivers/iio/humidity/ens210.c')
| -rw-r--r-- | drivers/iio/humidity/ens210.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/drivers/iio/humidity/ens210.c b/drivers/iio/humidity/ens210.c new file mode 100644 index 000000000000..77418d97f30d --- /dev/null +++ b/drivers/iio/humidity/ens210.c @@ -0,0 +1,339 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * ens210.c - Support for ScioSense ens210 temperature & humidity sensor family + * + * (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/crc7.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/iio/iio.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/types.h> + +#include <linux/unaligned.h> + +/* register definitions */ +#define ENS210_REG_PART_ID 0x00 +#define ENS210_REG_DIE_REV 0x02 +#define ENS210_REG_UID 0x04 +#define ENS210_REG_SYS_CTRL 0x10 +#define ENS210_REG_SYS_STAT 0x11 +#define ENS210_REG_SENS_RUN 0x21 +#define ENS210_REG_SENS_START 0x22 +#define ENS210_REG_SENS_STOP 0x23 +#define ENS210_REG_SENS_STAT 0x24 +#define ENS210_REG_T_VAL 0x30 +#define ENS210_REG_H_VAL 0x33 + +/* value definitions */ +#define ENS210_SENS_START_T_START BIT(0) +#define ENS210_SENS_START_H_START BIT(1) + +#define ENS210_SENS_STAT_T_ACTIVE BIT(0) +#define ENS210_SENS_STAT_H_ACTIVE BIT(1) + +#define ENS210_SYS_CTRL_LOW_POWER_ENABLE BIT(0) +#define ENS210_SYS_CTRL_SYS_RESET BIT(7) + +#define ENS210_SYS_STAT_SYS_ACTIVE BIT(0) + +enum ens210_partnumber { + ENS210 = 0x0210, + ENS210A = 0xa210, + ENS211 = 0x0211, + ENS212 = 0x0212, + ENS213A = 0xa213, + ENS215 = 0x0215, +}; + +/** + * struct ens210_chip_info - Humidity/Temperature chip specific information + * @name: name of device + * @part_id: chip identifier + * @conv_time_msec: time for conversion calculation in m/s + */ +struct ens210_chip_info { + const char *name; + enum ens210_partnumber part_id; + unsigned int conv_time_msec; +}; + +/** + * struct ens210_data - Humidity/Temperature sensor device structure + * @client: i2c client + * @chip_info: chip specific information + * @lock: lock protecting against simultaneous callers of get_measurement + * since multiple uninterrupted transactions are required + */ +struct ens210_data { + struct i2c_client *client; + const struct ens210_chip_info *chip_info; + struct mutex lock; +}; + +/* calculate 17-bit crc7 */ +static u8 ens210_crc7(u32 val) +{ + unsigned int val_be = (val & 0x1ffff) >> 0x8; + + return crc7_be(0xde, (u8 *)&val_be, 3) >> 1; +} + +static int ens210_get_measurement(struct iio_dev *indio_dev, bool temp, int *val) +{ + struct ens210_data *data = iio_priv(indio_dev); + struct device *dev = &data->client->dev; + u32 regval; + u8 regval_le[3]; + int ret; + + /* assert read */ + ret = i2c_smbus_write_byte_data(data->client, ENS210_REG_SENS_START, + temp ? ENS210_SENS_START_T_START : + ENS210_SENS_START_H_START); + if (ret) + return ret; + + /* wait for conversion to be ready */ + msleep(data->chip_info->conv_time_msec); + + ret = i2c_smbus_read_byte_data(data->client, ENS210_REG_SENS_STAT); + if (ret < 0) + return ret; + + /* perform read */ + ret = i2c_smbus_read_i2c_block_data( + data->client, temp ? ENS210_REG_T_VAL : ENS210_REG_H_VAL, 3, + regval_le); + if (ret < 0) { + dev_err(dev, "failed to read register"); + return -EIO; + } + if (ret != 3) { + dev_err(dev, "expected 3 bytes, received %d\n", ret); + return -EIO; + } + + regval = get_unaligned_le24(regval_le); + if (ens210_crc7(regval) != ((regval >> 17) & 0x7f)) { + dev_err(dev, "invalid crc\n"); + return -EIO; + } + + if (!((regval >> 16) & 0x1)) { + dev_err(dev, "data is not valid"); + return -EIO; + } + + *val = regval & GENMASK(15, 0); + return IIO_VAL_INT; +} + +static int ens210_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *channel, int *val, + int *val2, long mask) +{ + struct ens210_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + scoped_guard(mutex, &data->lock) { + ret = ens210_get_measurement( + indio_dev, channel->type == IIO_TEMP, val); + if (ret) + return ret; + return IIO_VAL_INT; + } + return -EINVAL; /* compiler warning workaround */ + case IIO_CHAN_INFO_SCALE: + if (channel->type == IIO_TEMP) { + *val = 15; + *val2 = 625000; + } else { + *val = 1; + *val2 = 953125; + } + return IIO_VAL_INT_PLUS_MICRO; + case IIO_CHAN_INFO_OFFSET: + *val = -17481; + *val2 = 600000; + return IIO_VAL_INT_PLUS_MICRO; + default: + return -EINVAL; + } +} + +static const struct iio_chan_spec ens210_channels[] = { + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OFFSET), + }, + { + .type = IIO_HUMIDITYRELATIVE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + } +}; + +static const struct iio_info ens210_info = { + .read_raw = ens210_read_raw, +}; + +static int ens210_probe(struct i2c_client *client) +{ + struct ens210_data *data; + struct iio_dev *indio_dev; + uint16_t part_id; + int ret; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_WRITE_BYTE_DATA | + I2C_FUNC_SMBUS_WRITE_BYTE | + I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { + return dev_err_probe(&client->dev, -EOPNOTSUPP, + "adapter does not support some i2c transactions\n"); + } + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + data->client = client; + mutex_init(&data->lock); + data->chip_info = i2c_get_match_data(client); + + ret = devm_regulator_get_enable(&client->dev, "vdd"); + if (ret) + return ret; + + /* reset device */ + ret = i2c_smbus_write_byte_data(client, ENS210_REG_SYS_CTRL, + ENS210_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, ENS210_REG_SYS_CTRL, 0x00); + if (ret) + return ret; + + /* wait for device to finish */ + usleep_range(4000, 5000); + + /* get part_id */ + ret = i2c_smbus_read_word_data(client, ENS210_REG_PART_ID); + if (ret < 0) + return ret; + part_id = ret; + + if (part_id != data->chip_info->part_id) { + dev_info(&client->dev, + "Part ID does not match (0x%04x != 0x%04x)\n", part_id, + data->chip_info->part_id); + } + + /* reenable low power */ + ret = i2c_smbus_write_byte_data(client, ENS210_REG_SYS_CTRL, + ENS210_SYS_CTRL_LOW_POWER_ENABLE); + if (ret) + return ret; + + indio_dev->name = data->chip_info->name; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = ens210_channels; + indio_dev->num_channels = ARRAY_SIZE(ens210_channels); + indio_dev->info = &ens210_info; + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static const struct ens210_chip_info ens210_chip_info_data = { + .name = "ens210", + .part_id = ENS210, + .conv_time_msec = 130, +}; + +static const struct ens210_chip_info ens210a_chip_info_data = { + .name = "ens210a", + .part_id = ENS210A, + .conv_time_msec = 130, +}; + +static const struct ens210_chip_info ens211_chip_info_data = { + .name = "ens211", + .part_id = ENS211, + .conv_time_msec = 32, +}; + +static const struct ens210_chip_info ens212_chip_info_data = { + .name = "ens212", + .part_id = ENS212, + .conv_time_msec = 32, +}; + +static const struct ens210_chip_info ens213a_chip_info_data = { + .name = "ens213a", + .part_id = ENS213A, + .conv_time_msec = 130, +}; + +static const struct ens210_chip_info ens215_chip_info_data = { + .name = "ens215", + .part_id = ENS215, + .conv_time_msec = 130, +}; + +static const struct of_device_id ens210_of_match[] = { + { .compatible = "sciosense,ens210", .data = &ens210_chip_info_data }, + { .compatible = "sciosense,ens210a", .data = &ens210a_chip_info_data }, + { .compatible = "sciosense,ens211", .data = &ens211_chip_info_data }, + { .compatible = "sciosense,ens212", .data = &ens212_chip_info_data }, + { .compatible = "sciosense,ens213a", .data = &ens213a_chip_info_data }, + { .compatible = "sciosense,ens215", .data = &ens215_chip_info_data }, + { } +}; +MODULE_DEVICE_TABLE(of, ens210_of_match); + +static const struct i2c_device_id ens210_id_table[] = { + { "ens210", (kernel_ulong_t)&ens210_chip_info_data }, + { "ens210a", (kernel_ulong_t)&ens210a_chip_info_data }, + { "ens211", (kernel_ulong_t)&ens211_chip_info_data }, + { "ens212", (kernel_ulong_t)&ens212_chip_info_data }, + { "ens213a", (kernel_ulong_t)&ens213a_chip_info_data }, + { "ens215", (kernel_ulong_t)&ens215_chip_info_data }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ens210_id_table); + +static struct i2c_driver ens210_driver = { + .probe = ens210_probe, + .id_table = ens210_id_table, + .driver = { + .name = "ens210", + .of_match_table = ens210_of_match, + }, +}; +module_i2c_driver(ens210_driver); + +MODULE_DESCRIPTION("ScioSense ENS210 temperature and humidity sensor driver"); +MODULE_AUTHOR("Joshua Felmeden <jfelmeden@thegoodpenguin.co.uk>"); +MODULE_LICENSE("GPL"); |