^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * si7020.c - Silicon Labs Si7013/20/21 Relative Humidity and Temp Sensors
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Copyright (c) 2013,2014 Uplogix, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * David Barksdale <dbarksdale@uplogix.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * The Silicon Labs Si7013/20/21 Relative Humidity and Temperature Sensors
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * are i2c devices which have an identical programming interface for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * measuring relative humidity and temperature. The Si7013 has an additional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * temperature input which this driver does not support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * Data Sheets:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * Si7013: http://www.silabs.com/Support%20Documents/TechnicalDocs/Si7013.pdf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * Si7020: http://www.silabs.com/Support%20Documents/TechnicalDocs/Si7020.pdf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * Si7021: http://www.silabs.com/Support%20Documents/TechnicalDocs/Si7021.pdf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/delay.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/i2c.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/mod_devicetable.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/sysfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/iio/iio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <linux/iio/sysfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) /* Measure Relative Humidity, Hold Master Mode */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #define SI7020CMD_RH_HOLD 0xE5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) /* Measure Temperature, Hold Master Mode */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #define SI7020CMD_TEMP_HOLD 0xE3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) /* Software Reset */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #define SI7020CMD_RESET 0xFE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static int si7020_read_raw(struct iio_dev *indio_dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) struct iio_chan_spec const *chan, int *val,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) int *val2, long mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) struct i2c_client **client = iio_priv(indio_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) switch (mask) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) case IIO_CHAN_INFO_RAW:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) ret = i2c_smbus_read_word_swapped(*client,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) chan->type == IIO_TEMP ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) SI7020CMD_TEMP_HOLD :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) SI7020CMD_RH_HOLD);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) *val = ret >> 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) * Humidity values can slightly exceed the 0-100%RH
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) * range and should be corrected by software
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) if (chan->type == IIO_HUMIDITYRELATIVE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) *val = clamp_val(*val, 786, 13893);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) return IIO_VAL_INT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) case IIO_CHAN_INFO_SCALE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) if (chan->type == IIO_TEMP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) *val = 175720; /* = 175.72 * 1000 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) *val = 125 * 1000;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) *val2 = 65536 >> 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) return IIO_VAL_FRACTIONAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) case IIO_CHAN_INFO_OFFSET:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * Since iio_convert_raw_to_processed_unlocked assumes offset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) * is an integer we have to round these values and lose
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) * accuracy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) * Relative humidity will be 0.0032959% too high and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) * temperature will be 0.00277344 degrees too high.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) * This is no big deal because it's within the accuracy of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) * sensor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) if (chan->type == IIO_TEMP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) *val = -4368; /* = -46.85 * (65536 >> 2) / 175.72 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) *val = -786; /* = -6 * (65536 >> 2) / 125 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return IIO_VAL_INT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) static const struct iio_chan_spec si7020_channels[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) .type = IIO_HUMIDITYRELATIVE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) .type = IIO_TEMP,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) static const struct iio_info si7020_info = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) .read_raw = si7020_read_raw,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) static int si7020_probe(struct i2c_client *client,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) const struct i2c_device_id *id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) struct iio_dev *indio_dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) struct i2c_client **data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) if (!i2c_check_functionality(client->adapter,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) I2C_FUNC_SMBUS_WRITE_BYTE |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) I2C_FUNC_SMBUS_READ_WORD_DATA))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) return -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) /* Reset device, loads default settings. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) ret = i2c_smbus_write_byte(client, SI7020CMD_RESET);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) /* Wait the maximum power-up time after software reset. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) msleep(15);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) if (!indio_dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) data = iio_priv(indio_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) *data = client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) indio_dev->name = dev_name(&client->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) indio_dev->modes = INDIO_DIRECT_MODE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) indio_dev->info = &si7020_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) indio_dev->channels = si7020_channels;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) indio_dev->num_channels = ARRAY_SIZE(si7020_channels);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) return devm_iio_device_register(&client->dev, indio_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) static const struct i2c_device_id si7020_id[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) { "si7020", 0 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) { "th06", 0 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) MODULE_DEVICE_TABLE(i2c, si7020_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) static const struct of_device_id si7020_dt_ids[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) { .compatible = "silabs,si7020" },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) MODULE_DEVICE_TABLE(of, si7020_dt_ids);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) static struct i2c_driver si7020_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) .driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) .name = "si7020",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) .of_match_table = si7020_dt_ids,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) .probe = si7020_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) .id_table = si7020_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) module_i2c_driver(si7020_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) MODULE_DESCRIPTION("Silicon Labs Si7013/20/21 Relative Humidity and Temperature Sensors");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) MODULE_LICENSE("GPL");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
3 Commits
0 Branches
0 Tags