// SPDX-License-Identifier: GPL-2.0-only
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/*
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* si7005.c - Support for Silabs Si7005 humidity and temperature sensor
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*
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* Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
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*
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* (7-bit I2C slave address 0x40)
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*
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* TODO: heater, fast mode, processed mode (temp. / linearity compensation)
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*/
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/delay.h>
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#include <linux/module.h>
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#include <linux/pm.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#define SI7005_STATUS 0x00
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#define SI7005_DATA 0x01 /* 16-bit, MSB */
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#define SI7005_CONFIG 0x03
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#define SI7005_ID 0x11
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#define SI7005_STATUS_NRDY BIT(0)
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#define SI7005_CONFIG_TEMP BIT(4)
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#define SI7005_CONFIG_START BIT(0)
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#define SI7005_ID_7005 0x50
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#define SI7005_ID_7015 0xf0
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struct si7005_data {
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struct i2c_client *client;
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struct mutex lock;
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u8 config;
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};
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static int si7005_read_measurement(struct si7005_data *data, bool temp)
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{
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int tries = 50;
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int ret;
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mutex_lock(&data->lock);
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ret = i2c_smbus_write_byte_data(data->client, SI7005_CONFIG,
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data->config | SI7005_CONFIG_START |
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(temp ? SI7005_CONFIG_TEMP : 0));
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if (ret < 0)
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goto done;
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while (tries-- > 0) {
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msleep(20);
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ret = i2c_smbus_read_byte_data(data->client, SI7005_STATUS);
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if (ret < 0)
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goto done;
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if (!(ret & SI7005_STATUS_NRDY))
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break;
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}
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if (tries < 0) {
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ret = -EIO;
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goto done;
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}
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ret = i2c_smbus_read_word_swapped(data->client, SI7005_DATA);
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done:
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mutex_unlock(&data->lock);
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return ret;
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}
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static int si7005_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan, int *val,
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int *val2, long mask)
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{
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struct si7005_data *data = iio_priv(indio_dev);
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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ret = si7005_read_measurement(data, chan->type == IIO_TEMP);
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if (ret < 0)
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return ret;
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*val = ret;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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if (chan->type == IIO_TEMP) {
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*val = 7;
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*val2 = 812500;
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} else {
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*val = 3;
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*val2 = 906250;
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}
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return IIO_VAL_INT_PLUS_MICRO;
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case IIO_CHAN_INFO_OFFSET:
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if (chan->type == IIO_TEMP)
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*val = -50 * 32 * 4;
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else
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*val = -24 * 16 * 16;
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return IIO_VAL_INT;
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default:
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break;
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}
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return -EINVAL;
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}
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static const struct iio_chan_spec si7005_channels[] = {
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{
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.type = IIO_HUMIDITYRELATIVE,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
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BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET),
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},
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{
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.type = IIO_TEMP,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
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BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET),
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}
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};
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static const struct iio_info si7005_info = {
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.read_raw = si7005_read_raw,
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};
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static int si7005_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct iio_dev *indio_dev;
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struct si7005_data *data;
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int ret;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
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return -EOPNOTSUPP;
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
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if (!indio_dev)
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return -ENOMEM;
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data = iio_priv(indio_dev);
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i2c_set_clientdata(client, indio_dev);
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data->client = client;
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mutex_init(&data->lock);
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indio_dev->name = dev_name(&client->dev);
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->info = &si7005_info;
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indio_dev->channels = si7005_channels;
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indio_dev->num_channels = ARRAY_SIZE(si7005_channels);
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ret = i2c_smbus_read_byte_data(client, SI7005_ID);
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if (ret < 0)
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return ret;
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if (ret != SI7005_ID_7005 && ret != SI7005_ID_7015)
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return -ENODEV;
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ret = i2c_smbus_read_byte_data(client, SI7005_CONFIG);
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if (ret < 0)
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return ret;
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data->config = ret;
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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 si7005_id[] = {
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{ "si7005", 0 },
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{ "th02", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, si7005_id);
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static struct i2c_driver si7005_driver = {
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.driver = {
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.name = "si7005",
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},
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.probe = si7005_probe,
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.id_table = si7005_id,
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};
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module_i2c_driver(si7005_driver);
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MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
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MODULE_DESCRIPTION("Silabs Si7005 humidity and temperature sensor driver");
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MODULE_LICENSE("GPL");
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