| /* |
| * si7005.c - Support for Silabs Si7005 humidity and temperature sensor |
| * |
| * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net> |
| * |
| * This file is subject to the terms and conditions of version 2 of |
| * the GNU General Public License. See the file COPYING in the main |
| * directory of this archive for more details. |
| * |
| * (7-bit I2C slave address 0x40) |
| * |
| * TODO: heater, fast mode, processed mode (temp. / linearity compensation) |
| */ |
| |
| #include <linux/err.h> |
| #include <linux/i2c.h> |
| #include <linux/delay.h> |
| #include <linux/module.h> |
| #include <linux/pm.h> |
| |
| #include <linux/iio/iio.h> |
| #include <linux/iio/sysfs.h> |
| |
| #define SI7005_STATUS 0x00 |
| #define SI7005_DATA 0x01 /* 16-bit, MSB */ |
| #define SI7005_CONFIG 0x03 |
| #define SI7005_ID 0x11 |
| |
| #define SI7005_STATUS_NRDY BIT(0) |
| #define SI7005_CONFIG_TEMP BIT(4) |
| #define SI7005_CONFIG_START BIT(0) |
| |
| #define SI7005_ID_7005 0x50 |
| #define SI7005_ID_7015 0xf0 |
| |
| struct si7005_data { |
| struct i2c_client *client; |
| struct mutex lock; |
| u8 config; |
| }; |
| |
| static int si7005_read_measurement(struct si7005_data *data, bool temp) |
| { |
| int tries = 50; |
| int ret; |
| |
| mutex_lock(&data->lock); |
| |
| ret = i2c_smbus_write_byte_data(data->client, SI7005_CONFIG, |
| data->config | SI7005_CONFIG_START | |
| (temp ? SI7005_CONFIG_TEMP : 0)); |
| if (ret < 0) |
| goto done; |
| |
| while (tries-- > 0) { |
| msleep(20); |
| ret = i2c_smbus_read_byte_data(data->client, SI7005_STATUS); |
| if (ret < 0) |
| goto done; |
| if (!(ret & SI7005_STATUS_NRDY)) |
| break; |
| } |
| if (tries < 0) { |
| ret = -EIO; |
| goto done; |
| } |
| |
| ret = i2c_smbus_read_word_swapped(data->client, SI7005_DATA); |
| |
| done: |
| mutex_unlock(&data->lock); |
| |
| return ret; |
| } |
| |
| static int si7005_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, int *val, |
| int *val2, long mask) |
| { |
| struct si7005_data *data = iio_priv(indio_dev); |
| int ret; |
| |
| switch (mask) { |
| case IIO_CHAN_INFO_RAW: |
| ret = si7005_read_measurement(data, chan->type == IIO_TEMP); |
| if (ret < 0) |
| return ret; |
| *val = ret; |
| return IIO_VAL_INT; |
| case IIO_CHAN_INFO_SCALE: |
| if (chan->type == IIO_TEMP) { |
| *val = 7; |
| *val2 = 812500; |
| } else { |
| *val = 3; |
| *val2 = 906250; |
| } |
| return IIO_VAL_INT_PLUS_MICRO; |
| case IIO_CHAN_INFO_OFFSET: |
| if (chan->type == IIO_TEMP) |
| *val = -50 * 32 * 4; |
| else |
| *val = -24 * 16 * 16; |
| return IIO_VAL_INT; |
| default: |
| break; |
| } |
| |
| return -EINVAL; |
| } |
| |
| static const struct iio_chan_spec si7005_channels[] = { |
| { |
| .type = IIO_HUMIDITYRELATIVE, |
| .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
| BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET), |
| }, |
| { |
| .type = IIO_TEMP, |
| .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
| BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET), |
| } |
| }; |
| |
| static const struct iio_info si7005_info = { |
| .read_raw = si7005_read_raw, |
| .driver_module = THIS_MODULE, |
| }; |
| |
| static int si7005_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| struct iio_dev *indio_dev; |
| struct si7005_data *data; |
| int ret; |
| |
| if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) |
| return -ENODEV; |
| |
| indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
| if (!indio_dev) |
| return -ENOMEM; |
| |
| data = iio_priv(indio_dev); |
| i2c_set_clientdata(client, indio_dev); |
| data->client = client; |
| mutex_init(&data->lock); |
| |
| indio_dev->dev.parent = &client->dev; |
| indio_dev->name = dev_name(&client->dev); |
| indio_dev->modes = INDIO_DIRECT_MODE; |
| indio_dev->info = &si7005_info; |
| |
| indio_dev->channels = si7005_channels; |
| indio_dev->num_channels = ARRAY_SIZE(si7005_channels); |
| |
| ret = i2c_smbus_read_byte_data(client, SI7005_ID); |
| if (ret < 0) |
| return ret; |
| if (ret != SI7005_ID_7005 && ret != SI7005_ID_7015) |
| return -ENODEV; |
| |
| ret = i2c_smbus_read_byte_data(client, SI7005_CONFIG); |
| if (ret < 0) |
| return ret; |
| data->config = ret; |
| |
| return devm_iio_device_register(&client->dev, indio_dev); |
| } |
| |
| static const struct i2c_device_id si7005_id[] = { |
| { "si7005", 0 }, |
| { "th02", 0 }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(i2c, si7005_id); |
| |
| static struct i2c_driver si7005_driver = { |
| .driver = { |
| .name = "si7005", |
| }, |
| .probe = si7005_probe, |
| .id_table = si7005_id, |
| }; |
| module_i2c_driver(si7005_driver); |
| |
| MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); |
| MODULE_DESCRIPTION("Silabs Si7005 humidity and temperature sensor driver"); |
| MODULE_LICENSE("GPL"); |