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184 lines
4.0 KiB
184 lines
4.0 KiB
// 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 <[email protected]> |
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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 <[email protected]>"); |
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MODULE_DESCRIPTION("Silabs Si7005 humidity and temperature sensor driver"); |
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MODULE_LICENSE("GPL");
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