// SPDX-License-Identifier: GPL-2.0-only
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/*
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* htu21.c - Support for Measurement-Specialties
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* htu21 temperature & humidity sensor
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* and humidity part of MS8607 sensor
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*
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* Copyright (c) 2014 Measurement-Specialties
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*
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* (7-bit I2C slave address 0x40)
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*
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* Datasheet:
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* http://www.meas-spec.com/downloads/HTU21D.pdf
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* Datasheet:
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* http://www.meas-spec.com/downloads/MS8607-02BA01.pdf
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*/
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/stat.h>
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include "../common/ms_sensors/ms_sensors_i2c.h"
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#define HTU21_RESET 0xFE
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enum {
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HTU21,
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MS8607
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};
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static const int htu21_samp_freq[4] = { 20, 40, 70, 120 };
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/* String copy of the above const for readability purpose */
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static const char htu21_show_samp_freq[] = "20 40 70 120";
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static int htu21_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *channel, int *val,
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int *val2, long mask)
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{
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int ret, temperature;
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unsigned int humidity;
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struct ms_ht_dev *dev_data = iio_priv(indio_dev);
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switch (mask) {
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case IIO_CHAN_INFO_PROCESSED:
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switch (channel->type) {
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case IIO_TEMP: /* in milli °C */
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ret = ms_sensors_ht_read_temperature(dev_data,
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&temperature);
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if (ret)
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return ret;
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*val = temperature;
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return IIO_VAL_INT;
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case IIO_HUMIDITYRELATIVE: /* in milli %RH */
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ret = ms_sensors_ht_read_humidity(dev_data,
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&humidity);
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if (ret)
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return ret;
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*val = humidity;
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return IIO_VAL_INT;
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default:
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return -EINVAL;
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}
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case IIO_CHAN_INFO_SAMP_FREQ:
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*val = htu21_samp_freq[dev_data->res_index];
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return IIO_VAL_INT;
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default:
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return -EINVAL;
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}
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}
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static int htu21_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val, int val2, long mask)
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{
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struct ms_ht_dev *dev_data = iio_priv(indio_dev);
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int i, ret;
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switch (mask) {
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case IIO_CHAN_INFO_SAMP_FREQ:
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i = ARRAY_SIZE(htu21_samp_freq);
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while (i-- > 0)
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if (val == htu21_samp_freq[i])
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break;
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if (i < 0)
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return -EINVAL;
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mutex_lock(&dev_data->lock);
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dev_data->res_index = i;
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ret = ms_sensors_write_resolution(dev_data, i);
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mutex_unlock(&dev_data->lock);
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return ret;
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default:
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return -EINVAL;
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}
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}
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static const struct iio_chan_spec htu21_channels[] = {
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{
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.type = IIO_TEMP,
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
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.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
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},
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{
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.type = IIO_HUMIDITYRELATIVE,
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
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.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
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}
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};
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/*
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* Meas Spec recommendation is to not read temperature
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* on this driver part for MS8607
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*/
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static const struct iio_chan_spec ms8607_channels[] = {
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{
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.type = IIO_HUMIDITYRELATIVE,
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
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.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
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}
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};
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static ssize_t htu21_show_battery_low(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct ms_ht_dev *dev_data = iio_priv(indio_dev);
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return ms_sensors_show_battery_low(dev_data, buf);
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}
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static ssize_t htu21_show_heater(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct ms_ht_dev *dev_data = iio_priv(indio_dev);
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return ms_sensors_show_heater(dev_data, buf);
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}
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static ssize_t htu21_write_heater(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t len)
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct ms_ht_dev *dev_data = iio_priv(indio_dev);
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return ms_sensors_write_heater(dev_data, buf, len);
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}
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static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(htu21_show_samp_freq);
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static IIO_DEVICE_ATTR(battery_low, S_IRUGO,
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htu21_show_battery_low, NULL, 0);
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static IIO_DEVICE_ATTR(heater_enable, S_IRUGO | S_IWUSR,
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htu21_show_heater, htu21_write_heater, 0);
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static struct attribute *htu21_attributes[] = {
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&iio_const_attr_sampling_frequency_available.dev_attr.attr,
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&iio_dev_attr_battery_low.dev_attr.attr,
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&iio_dev_attr_heater_enable.dev_attr.attr,
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NULL,
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};
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static const struct attribute_group htu21_attribute_group = {
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.attrs = htu21_attributes,
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};
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static const struct iio_info htu21_info = {
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.read_raw = htu21_read_raw,
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.write_raw = htu21_write_raw,
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.attrs = &htu21_attribute_group,
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};
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static int htu21_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct ms_ht_dev *dev_data;
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struct iio_dev *indio_dev;
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int ret;
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u64 serial_number;
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if (!i2c_check_functionality(client->adapter,
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I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
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I2C_FUNC_SMBUS_WRITE_BYTE |
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I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
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dev_err(&client->dev,
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"Adapter does not support some i2c transaction\n");
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return -EOPNOTSUPP;
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}
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));
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if (!indio_dev)
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return -ENOMEM;
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dev_data = iio_priv(indio_dev);
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dev_data->client = client;
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dev_data->res_index = 0;
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mutex_init(&dev_data->lock);
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indio_dev->info = &htu21_info;
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indio_dev->name = id->name;
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indio_dev->modes = INDIO_DIRECT_MODE;
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if (id->driver_data == MS8607) {
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indio_dev->channels = ms8607_channels;
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indio_dev->num_channels = ARRAY_SIZE(ms8607_channels);
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} else {
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indio_dev->channels = htu21_channels;
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indio_dev->num_channels = ARRAY_SIZE(htu21_channels);
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}
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i2c_set_clientdata(client, indio_dev);
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ret = ms_sensors_reset(client, HTU21_RESET, 15000);
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if (ret)
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return ret;
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ret = ms_sensors_read_serial(client, &serial_number);
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if (ret)
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return ret;
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dev_info(&client->dev, "Serial number : %llx", serial_number);
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return devm_iio_device_register(&client->dev, indio_dev);
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}
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static const struct i2c_device_id htu21_id[] = {
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{"htu21", HTU21},
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{"ms8607-humidity", MS8607},
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{}
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};
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MODULE_DEVICE_TABLE(i2c, htu21_id);
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static const struct of_device_id htu21_of_match[] = {
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{ .compatible = "meas,htu21", },
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{ .compatible = "meas,ms8607-humidity", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, htu21_of_match);
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static struct i2c_driver htu21_driver = {
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.probe = htu21_probe,
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.id_table = htu21_id,
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.driver = {
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.name = "htu21",
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.of_match_table = htu21_of_match,
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},
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};
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module_i2c_driver(htu21_driver);
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MODULE_DESCRIPTION("Measurement-Specialties htu21 temperature and humidity driver");
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MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
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MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
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MODULE_LICENSE("GPL v2");
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