diff options
Diffstat (limited to 'drivers/iio/humidity/hdc3020.c')
| -rw-r--r-- | drivers/iio/humidity/hdc3020.c | 473 |
1 files changed, 473 insertions, 0 deletions
diff --git a/drivers/iio/humidity/hdc3020.c b/drivers/iio/humidity/hdc3020.c new file mode 100644 index 000000000000..4e3311170725 --- /dev/null +++ b/drivers/iio/humidity/hdc3020.c @@ -0,0 +1,473 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * hdc3020.c - Support for the TI HDC3020,HDC3021 and HDC3022 + * temperature + relative humidity sensors + * + * Copyright (C) 2023 + * + * Datasheet: https://www.ti.com/lit/ds/symlink/hdc3020.pdf + */ + +#include <linux/bitops.h> +#include <linux/cleanup.h> +#include <linux/crc8.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mutex.h> + +#include <asm/unaligned.h> + +#include <linux/iio/iio.h> + +#define HDC3020_HEATER_CMD_MSB 0x30 /* shared by all heater commands */ +#define HDC3020_HEATER_ENABLE 0x6D +#define HDC3020_HEATER_DISABLE 0x66 +#define HDC3020_HEATER_CONFIG 0x6E + +#define HDC3020_READ_RETRY_TIMES 10 +#define HDC3020_BUSY_DELAY_MS 10 + +#define HDC3020_CRC8_POLYNOMIAL 0x31 + +static const u8 HDC3020_S_AUTO_10HZ_MOD0[2] = { 0x27, 0x37 }; + +static const u8 HDC3020_EXIT_AUTO[2] = { 0x30, 0x93 }; + +static const u8 HDC3020_R_T_RH_AUTO[2] = { 0xE0, 0x00 }; +static const u8 HDC3020_R_T_LOW_AUTO[2] = { 0xE0, 0x02 }; +static const u8 HDC3020_R_T_HIGH_AUTO[2] = { 0xE0, 0x03 }; +static const u8 HDC3020_R_RH_LOW_AUTO[2] = { 0xE0, 0x04 }; +static const u8 HDC3020_R_RH_HIGH_AUTO[2] = { 0xE0, 0x05 }; + +struct hdc3020_data { + struct i2c_client *client; + /* + * Ensure that the sensor configuration (currently only heater is + * supported) will not be changed during the process of reading + * sensor data (this driver will try HDC3020_READ_RETRY_TIMES times + * if the device does not respond). + */ + struct mutex lock; +}; + +static const int hdc3020_heater_vals[] = {0, 1, 0x3FFF}; + +static const struct iio_chan_spec hdc3020_channels[] = { + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_PEAK) | + BIT(IIO_CHAN_INFO_TROUGH) | BIT(IIO_CHAN_INFO_OFFSET), + }, + { + .type = IIO_HUMIDITYRELATIVE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_PEAK) | + BIT(IIO_CHAN_INFO_TROUGH), + }, + { + /* + * For setting the internal heater, which can be switched on to + * prevent or remove any condensation that may develop when the + * ambient environment approaches its dew point temperature. + */ + .type = IIO_CURRENT, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW), + .output = 1, + }, +}; + +DECLARE_CRC8_TABLE(hdc3020_crc8_table); + +static int hdc3020_write_bytes(struct hdc3020_data *data, const u8 *buf, u8 len) +{ + struct i2c_client *client = data->client; + struct i2c_msg msg; + int ret, cnt; + + msg.addr = client->addr; + msg.flags = 0; + msg.buf = (char *)buf; + msg.len = len; + + /* + * During the measurement process, HDC3020 will not return data. + * So wait for a while and try again + */ + for (cnt = 0; cnt < HDC3020_READ_RETRY_TIMES; cnt++) { + ret = i2c_transfer(client->adapter, &msg, 1); + if (ret == 1) + return 0; + + mdelay(HDC3020_BUSY_DELAY_MS); + } + dev_err(&client->dev, "Could not write sensor command\n"); + + return -ETIMEDOUT; +} + +static int hdc3020_read_bytes(struct hdc3020_data *data, const u8 *buf, + void *val, int len) +{ + int ret, cnt; + struct i2c_client *client = data->client; + struct i2c_msg msg[2] = { + [0] = { + .addr = client->addr, + .flags = 0, + .buf = (char *)buf, + .len = 2, + }, + [1] = { + .addr = client->addr, + .flags = I2C_M_RD, + .buf = val, + .len = len, + }, + }; + + /* + * During the measurement process, HDC3020 will not return data. + * So wait for a while and try again + */ + for (cnt = 0; cnt < HDC3020_READ_RETRY_TIMES; cnt++) { + ret = i2c_transfer(client->adapter, msg, 2); + if (ret == 2) + return 0; + + mdelay(HDC3020_BUSY_DELAY_MS); + } + dev_err(&client->dev, "Could not read sensor data\n"); + + return -ETIMEDOUT; +} + +static int hdc3020_read_measurement(struct hdc3020_data *data, + enum iio_chan_type type, int *val) +{ + u8 crc, buf[6]; + int ret; + + ret = hdc3020_read_bytes(data, HDC3020_R_T_RH_AUTO, buf, 6); + if (ret < 0) + return ret; + + /* CRC check of the temperature measurement */ + crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE); + if (crc != buf[2]) + return -EINVAL; + + /* CRC check of the relative humidity measurement */ + crc = crc8(hdc3020_crc8_table, buf + 3, 2, CRC8_INIT_VALUE); + if (crc != buf[5]) + return -EINVAL; + + if (type == IIO_TEMP) + *val = get_unaligned_be16(buf); + else if (type == IIO_HUMIDITYRELATIVE) + *val = get_unaligned_be16(&buf[3]); + else + return -EINVAL; + + return 0; +} + +/* + * After exiting the automatic measurement mode or resetting, the peak + * value will be reset to the default value + * This method is used to get the highest temp measured during automatic + * measurement + */ +static int hdc3020_read_high_peak_t(struct hdc3020_data *data, int *val) +{ + u8 crc, buf[3]; + int ret; + + ret = hdc3020_read_bytes(data, HDC3020_R_T_HIGH_AUTO, buf, 3); + if (ret < 0) + return ret; + + crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE); + if (crc != buf[2]) + return -EINVAL; + + *val = get_unaligned_be16(buf); + + return 0; +} + +/* + * This method is used to get the lowest temp measured during automatic + * measurement + */ +static int hdc3020_read_low_peak_t(struct hdc3020_data *data, int *val) +{ + u8 crc, buf[3]; + int ret; + + ret = hdc3020_read_bytes(data, HDC3020_R_T_LOW_AUTO, buf, 3); + if (ret < 0) + return ret; + + crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE); + if (crc != buf[2]) + return -EINVAL; + + *val = get_unaligned_be16(buf); + + return 0; +} + +/* + * This method is used to get the highest humidity measured during automatic + * measurement + */ +static int hdc3020_read_high_peak_rh(struct hdc3020_data *data, int *val) +{ + u8 crc, buf[3]; + int ret; + + ret = hdc3020_read_bytes(data, HDC3020_R_RH_HIGH_AUTO, buf, 3); + if (ret < 0) + return ret; + + crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE); + if (crc != buf[2]) + return -EINVAL; + + *val = get_unaligned_be16(buf); + + return 0; +} + +/* + * This method is used to get the lowest humidity measured during automatic + * measurement + */ +static int hdc3020_read_low_peak_rh(struct hdc3020_data *data, int *val) +{ + u8 crc, buf[3]; + int ret; + + ret = hdc3020_read_bytes(data, HDC3020_R_RH_LOW_AUTO, buf, 3); + if (ret < 0) + return ret; + + crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE); + if (crc != buf[2]) + return -EINVAL; + + *val = get_unaligned_be16(buf); + + return 0; +} + +static int hdc3020_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + struct hdc3020_data *data = iio_priv(indio_dev); + int ret; + + if (chan->type != IIO_TEMP && chan->type != IIO_HUMIDITYRELATIVE) + return -EINVAL; + + switch (mask) { + case IIO_CHAN_INFO_RAW: { + guard(mutex)(&data->lock); + ret = hdc3020_read_measurement(data, chan->type, val); + if (ret < 0) + return ret; + + return IIO_VAL_INT; + } + case IIO_CHAN_INFO_PEAK: { + guard(mutex)(&data->lock); + if (chan->type == IIO_TEMP) { + ret = hdc3020_read_high_peak_t(data, val); + if (ret < 0) + return ret; + } else { + ret = hdc3020_read_high_peak_rh(data, val); + if (ret < 0) + return ret; + } + return IIO_VAL_INT; + } + case IIO_CHAN_INFO_TROUGH: { + guard(mutex)(&data->lock); + if (chan->type == IIO_TEMP) { + ret = hdc3020_read_low_peak_t(data, val); + if (ret < 0) + return ret; + } else { + ret = hdc3020_read_low_peak_rh(data, val); + if (ret < 0) + return ret; + } + return IIO_VAL_INT; + } + case IIO_CHAN_INFO_SCALE: + *val2 = 65536; + if (chan->type == IIO_TEMP) + *val = 175; + else + *val = 100; + return IIO_VAL_FRACTIONAL; + + case IIO_CHAN_INFO_OFFSET: + if (chan->type != IIO_TEMP) + return -EINVAL; + + *val = 16852; + return IIO_VAL_INT; + + default: + return -EINVAL; + } +} + +static int hdc3020_read_available(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, + int *type, int *length, long mask) +{ + if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_CURRENT) + return -EINVAL; + + *vals = hdc3020_heater_vals; + *type = IIO_VAL_INT; + + return IIO_AVAIL_RANGE; +} + +static int hdc3020_update_heater(struct hdc3020_data *data, int val) +{ + u8 buf[5]; + int ret; + + if (val < hdc3020_heater_vals[0] || val > hdc3020_heater_vals[2]) + return -EINVAL; + + buf[0] = HDC3020_HEATER_CMD_MSB; + + if (!val) { + buf[1] = HDC3020_HEATER_DISABLE; + return hdc3020_write_bytes(data, buf, 2); + } + + buf[1] = HDC3020_HEATER_CONFIG; + put_unaligned_be16(val & GENMASK(13, 0), &buf[2]); + buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE); + ret = hdc3020_write_bytes(data, buf, 5); + if (ret < 0) + return ret; + + buf[1] = HDC3020_HEATER_ENABLE; + + return hdc3020_write_bytes(data, buf, 2); +} + +static int hdc3020_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct hdc3020_data *data = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (chan->type != IIO_CURRENT) + return -EINVAL; + + guard(mutex)(&data->lock); + return hdc3020_update_heater(data, val); + } + + return -EINVAL; +} + +static const struct iio_info hdc3020_info = { + .read_raw = hdc3020_read_raw, + .write_raw = hdc3020_write_raw, + .read_avail = hdc3020_read_available, +}; + +static void hdc3020_stop(void *data) +{ + hdc3020_write_bytes((struct hdc3020_data *)data, HDC3020_EXIT_AUTO, 2); +} + +static int hdc3020_probe(struct i2c_client *client) +{ + struct iio_dev *indio_dev; + struct hdc3020_data *data; + int ret; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return -EOPNOTSUPP; + + 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); + + crc8_populate_msb(hdc3020_crc8_table, HDC3020_CRC8_POLYNOMIAL); + + indio_dev->name = "hdc3020"; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &hdc3020_info; + indio_dev->channels = hdc3020_channels; + indio_dev->num_channels = ARRAY_SIZE(hdc3020_channels); + + ret = hdc3020_write_bytes(data, HDC3020_S_AUTO_10HZ_MOD0, 2); + if (ret) + return dev_err_probe(&client->dev, ret, + "Unable to set up measurement\n"); + + ret = devm_add_action_or_reset(&data->client->dev, hdc3020_stop, data); + if (ret) + return ret; + + ret = devm_iio_device_register(&data->client->dev, indio_dev); + if (ret) + return dev_err_probe(&client->dev, ret, "Failed to add device"); + + return 0; +} + +static const struct i2c_device_id hdc3020_id[] = { + { "hdc3020" }, + { "hdc3021" }, + { "hdc3022" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, hdc3020_id); + +static const struct of_device_id hdc3020_dt_ids[] = { + { .compatible = "ti,hdc3020" }, + { .compatible = "ti,hdc3021" }, + { .compatible = "ti,hdc3022" }, + { } +}; +MODULE_DEVICE_TABLE(of, hdc3020_dt_ids); + +static struct i2c_driver hdc3020_driver = { + .driver = { + .name = "hdc3020", + .of_match_table = hdc3020_dt_ids, + }, + .probe = hdc3020_probe, + .id_table = hdc3020_id, +}; +module_i2c_driver(hdc3020_driver); + +MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gmail.com>"); +MODULE_AUTHOR("Li peiyu <579lpy@gmail.com>"); +MODULE_DESCRIPTION("TI HDC3020 humidity and temperature sensor driver"); +MODULE_LICENSE("GPL"); |