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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * htu21.c - Support for Measurement-Specialties4 * htu21 temperature & humidity sensor5 * and humidity part of MS8607 sensor6 *7 * Copyright (c) 2014 Measurement-Specialties8 *9 * (7-bit I2C slave address 0x40)10 *11 * Datasheet:12 * http://www.meas-spec.com/downloads/HTU21D.pdf13 * Datasheet:14 * http://www.meas-spec.com/downloads/MS8607-02BA01.pdf15 */16 17#include <linux/init.h>18#include <linux/device.h>19#include <linux/kernel.h>20#include <linux/stat.h>21#include <linux/module.h>22#include <linux/mod_devicetable.h>23#include <linux/iio/iio.h>24#include <linux/iio/sysfs.h>25 26#include "../common/ms_sensors/ms_sensors_i2c.h"27 28#define HTU21_RESET 0xFE29 30enum {31 HTU21,32 MS860733};34 35static const int htu21_samp_freq[4] = { 20, 40, 70, 120 };36/* String copy of the above const for readability purpose */37static const char htu21_show_samp_freq[] = "20 40 70 120";38 39static int htu21_read_raw(struct iio_dev *indio_dev,40 struct iio_chan_spec const *channel, int *val,41 int *val2, long mask)42{43 int ret, temperature;44 unsigned int humidity;45 struct ms_ht_dev *dev_data = iio_priv(indio_dev);46 47 switch (mask) {48 case IIO_CHAN_INFO_PROCESSED:49 switch (channel->type) {50 case IIO_TEMP: /* in milli °C */51 ret = ms_sensors_ht_read_temperature(dev_data,52 &temperature);53 if (ret)54 return ret;55 *val = temperature;56 57 return IIO_VAL_INT;58 case IIO_HUMIDITYRELATIVE: /* in milli %RH */59 ret = ms_sensors_ht_read_humidity(dev_data,60 &humidity);61 if (ret)62 return ret;63 *val = humidity;64 65 return IIO_VAL_INT;66 default:67 return -EINVAL;68 }69 case IIO_CHAN_INFO_SAMP_FREQ:70 *val = htu21_samp_freq[dev_data->res_index];71 72 return IIO_VAL_INT;73 default:74 return -EINVAL;75 }76}77 78static int htu21_write_raw(struct iio_dev *indio_dev,79 struct iio_chan_spec const *chan,80 int val, int val2, long mask)81{82 struct ms_ht_dev *dev_data = iio_priv(indio_dev);83 int i, ret;84 85 switch (mask) {86 case IIO_CHAN_INFO_SAMP_FREQ:87 i = ARRAY_SIZE(htu21_samp_freq);88 while (i-- > 0)89 if (val == htu21_samp_freq[i])90 break;91 if (i < 0)92 return -EINVAL;93 mutex_lock(&dev_data->lock);94 dev_data->res_index = i;95 ret = ms_sensors_write_resolution(dev_data, i);96 mutex_unlock(&dev_data->lock);97 98 return ret;99 default:100 return -EINVAL;101 }102}103 104static const struct iio_chan_spec htu21_channels[] = {105 {106 .type = IIO_TEMP,107 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),108 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),109 },110 {111 .type = IIO_HUMIDITYRELATIVE,112 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),113 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),114 }115};116 117/*118 * Meas Spec recommendation is to not read temperature119 * on this driver part for MS8607120 */121static const struct iio_chan_spec ms8607_channels[] = {122 {123 .type = IIO_HUMIDITYRELATIVE,124 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),125 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),126 }127};128 129static ssize_t htu21_show_battery_low(struct device *dev,130 struct device_attribute *attr, char *buf)131{132 struct iio_dev *indio_dev = dev_to_iio_dev(dev);133 struct ms_ht_dev *dev_data = iio_priv(indio_dev);134 135 return ms_sensors_show_battery_low(dev_data, buf);136}137 138static ssize_t htu21_show_heater(struct device *dev,139 struct device_attribute *attr, char *buf)140{141 struct iio_dev *indio_dev = dev_to_iio_dev(dev);142 struct ms_ht_dev *dev_data = iio_priv(indio_dev);143 144 return ms_sensors_show_heater(dev_data, buf);145}146 147static ssize_t htu21_write_heater(struct device *dev,148 struct device_attribute *attr,149 const char *buf, size_t len)150{151 struct iio_dev *indio_dev = dev_to_iio_dev(dev);152 struct ms_ht_dev *dev_data = iio_priv(indio_dev);153 154 return ms_sensors_write_heater(dev_data, buf, len);155}156 157static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(htu21_show_samp_freq);158static IIO_DEVICE_ATTR(battery_low, S_IRUGO,159 htu21_show_battery_low, NULL, 0);160static IIO_DEVICE_ATTR(heater_enable, S_IRUGO | S_IWUSR,161 htu21_show_heater, htu21_write_heater, 0);162 163static struct attribute *htu21_attributes[] = {164 &iio_const_attr_sampling_frequency_available.dev_attr.attr,165 &iio_dev_attr_battery_low.dev_attr.attr,166 &iio_dev_attr_heater_enable.dev_attr.attr,167 NULL,168};169 170static const struct attribute_group htu21_attribute_group = {171 .attrs = htu21_attributes,172};173 174static const struct iio_info htu21_info = {175 .read_raw = htu21_read_raw,176 .write_raw = htu21_write_raw,177 .attrs = &htu21_attribute_group,178};179 180static int htu21_probe(struct i2c_client *client)181{182 const struct i2c_device_id *id = i2c_client_get_device_id(client);183 struct ms_ht_dev *dev_data;184 struct iio_dev *indio_dev;185 int ret;186 u64 serial_number;187 188 if (!i2c_check_functionality(client->adapter,189 I2C_FUNC_SMBUS_WRITE_BYTE_DATA |190 I2C_FUNC_SMBUS_WRITE_BYTE |191 I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {192 dev_err(&client->dev,193 "Adapter does not support some i2c transaction\n");194 return -EOPNOTSUPP;195 }196 197 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));198 if (!indio_dev)199 return -ENOMEM;200 201 dev_data = iio_priv(indio_dev);202 dev_data->client = client;203 dev_data->res_index = 0;204 mutex_init(&dev_data->lock);205 206 indio_dev->info = &htu21_info;207 indio_dev->name = id->name;208 indio_dev->modes = INDIO_DIRECT_MODE;209 210 if (id->driver_data == MS8607) {211 indio_dev->channels = ms8607_channels;212 indio_dev->num_channels = ARRAY_SIZE(ms8607_channels);213 } else {214 indio_dev->channels = htu21_channels;215 indio_dev->num_channels = ARRAY_SIZE(htu21_channels);216 }217 218 i2c_set_clientdata(client, indio_dev);219 220 ret = ms_sensors_reset(client, HTU21_RESET, 15000);221 if (ret)222 return ret;223 224 ret = ms_sensors_read_serial(client, &serial_number);225 if (ret)226 return ret;227 dev_info(&client->dev, "Serial number : %llx", serial_number);228 229 return devm_iio_device_register(&client->dev, indio_dev);230}231 232static const struct i2c_device_id htu21_id[] = {233 {"htu21", HTU21},234 {"ms8607-humidity", MS8607},235 {}236};237MODULE_DEVICE_TABLE(i2c, htu21_id);238 239static const struct of_device_id htu21_of_match[] = {240 { .compatible = "meas,htu21", },241 { .compatible = "meas,ms8607-humidity", },242 { },243};244MODULE_DEVICE_TABLE(of, htu21_of_match);245 246static struct i2c_driver htu21_driver = {247 .probe = htu21_probe,248 .id_table = htu21_id,249 .driver = {250 .name = "htu21",251 .of_match_table = htu21_of_match,252 },253};254 255module_i2c_driver(htu21_driver);256 257MODULE_DESCRIPTION("Measurement-Specialties htu21 temperature and humidity driver");258MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");259MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");260MODULE_LICENSE("GPL v2");261MODULE_IMPORT_NS(IIO_MEAS_SPEC_SENSORS);262