321 строка
7.6 KiB
C
321 строка
7.6 KiB
C
/*
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* hdc100x.c - Support for the TI HDC100x temperature + humidity sensors
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*
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* Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/delay.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/i2c.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#define HDC100X_REG_TEMP 0x00
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#define HDC100X_REG_HUMIDITY 0x01
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#define HDC100X_REG_CONFIG 0x02
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#define HDC100X_REG_CONFIG_HEATER_EN BIT(13)
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struct hdc100x_data {
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struct i2c_client *client;
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struct mutex lock;
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u16 config;
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/* integration time of the sensor */
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int adc_int_us[2];
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};
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/* integration time in us */
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static const int hdc100x_int_time[][3] = {
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{ 6350, 3650, 0 }, /* IIO_TEMP channel*/
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{ 6500, 3850, 2500 }, /* IIO_HUMIDITYRELATIVE channel */
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};
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/* HDC100X_REG_CONFIG shift and mask values */
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static const struct {
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int shift;
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int mask;
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} hdc100x_resolution_shift[2] = {
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{ /* IIO_TEMP channel */
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.shift = 10,
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.mask = 1
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},
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{ /* IIO_HUMIDITYRELATIVE channel */
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.shift = 8,
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.mask = 2,
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},
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};
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static IIO_CONST_ATTR(temp_integration_time_available,
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"0.00365 0.00635");
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static IIO_CONST_ATTR(humidityrelative_integration_time_available,
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"0.0025 0.00385 0.0065");
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static IIO_CONST_ATTR(out_current_heater_raw_available,
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"0 1");
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static struct attribute *hdc100x_attributes[] = {
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&iio_const_attr_temp_integration_time_available.dev_attr.attr,
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&iio_const_attr_humidityrelative_integration_time_available.dev_attr.attr,
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&iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
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NULL
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};
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static struct attribute_group hdc100x_attribute_group = {
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.attrs = hdc100x_attributes,
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};
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static const struct iio_chan_spec hdc100x_channels[] = {
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{
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.type = IIO_TEMP,
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.address = HDC100X_REG_TEMP,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
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BIT(IIO_CHAN_INFO_SCALE) |
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BIT(IIO_CHAN_INFO_INT_TIME) |
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BIT(IIO_CHAN_INFO_OFFSET),
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},
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{
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.type = IIO_HUMIDITYRELATIVE,
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.address = HDC100X_REG_HUMIDITY,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
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BIT(IIO_CHAN_INFO_SCALE) |
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BIT(IIO_CHAN_INFO_INT_TIME)
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},
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{
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.type = IIO_CURRENT,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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.extend_name = "heater",
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.output = 1,
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},
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};
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static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
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{
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int tmp = (~mask & data->config) | val;
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int ret;
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ret = i2c_smbus_write_word_swapped(data->client,
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HDC100X_REG_CONFIG, tmp);
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if (!ret)
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data->config = tmp;
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return ret;
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}
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static int hdc100x_set_it_time(struct hdc100x_data *data, int chan, int val2)
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{
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int shift = hdc100x_resolution_shift[chan].shift;
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int ret = -EINVAL;
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int i;
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for (i = 0; i < ARRAY_SIZE(hdc100x_int_time[chan]); i++) {
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if (val2 && val2 == hdc100x_int_time[chan][i]) {
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ret = hdc100x_update_config(data,
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hdc100x_resolution_shift[chan].mask << shift,
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i << shift);
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if (!ret)
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data->adc_int_us[chan] = val2;
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break;
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}
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}
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return ret;
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}
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static int hdc100x_get_measurement(struct hdc100x_data *data,
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struct iio_chan_spec const *chan)
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{
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struct i2c_client *client = data->client;
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int delay = data->adc_int_us[chan->address];
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int ret;
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int val;
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/* start measurement */
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ret = i2c_smbus_write_byte(client, chan->address);
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if (ret < 0) {
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dev_err(&client->dev, "cannot start measurement");
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return ret;
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}
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/* wait for integration time to pass */
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usleep_range(delay, delay + 1000);
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/*
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* i2c_smbus_read_word_data cannot() be used here due to the command
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* value not being understood and causes NAKs preventing any reading
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* from being accessed.
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*/
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ret = i2c_smbus_read_byte(client);
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if (ret < 0) {
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dev_err(&client->dev, "cannot read high byte measurement");
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return ret;
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}
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val = ret << 6;
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ret = i2c_smbus_read_byte(client);
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if (ret < 0) {
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dev_err(&client->dev, "cannot read low byte measurement");
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return ret;
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}
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val |= ret >> 2;
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return val;
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}
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static int hdc100x_get_heater_status(struct hdc100x_data *data)
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{
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return !!(data->config & HDC100X_REG_CONFIG_HEATER_EN);
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}
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static int hdc100x_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 hdc100x_data *data = iio_priv(indio_dev);
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switch (mask) {
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case IIO_CHAN_INFO_RAW: {
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int ret;
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mutex_lock(&data->lock);
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if (chan->type == IIO_CURRENT) {
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*val = hdc100x_get_heater_status(data);
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ret = IIO_VAL_INT;
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} else {
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ret = hdc100x_get_measurement(data, chan);
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if (ret >= 0) {
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*val = ret;
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ret = IIO_VAL_INT;
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}
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}
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mutex_unlock(&data->lock);
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return ret;
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}
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case IIO_CHAN_INFO_INT_TIME:
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*val = 0;
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*val2 = data->adc_int_us[chan->address];
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return IIO_VAL_INT_PLUS_MICRO;
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case IIO_CHAN_INFO_SCALE:
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if (chan->type == IIO_TEMP) {
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*val = 165;
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*val2 = 65536 >> 2;
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return IIO_VAL_FRACTIONAL;
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} else {
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*val = 0;
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*val2 = 10000;
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return IIO_VAL_INT_PLUS_MICRO;
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}
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break;
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case IIO_CHAN_INFO_OFFSET:
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*val = -3971;
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*val2 = 879096;
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return IIO_VAL_INT_PLUS_MICRO;
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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 hdc100x_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 hdc100x_data *data = iio_priv(indio_dev);
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int ret = -EINVAL;
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switch (mask) {
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case IIO_CHAN_INFO_INT_TIME:
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if (val != 0)
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return -EINVAL;
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mutex_lock(&data->lock);
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ret = hdc100x_set_it_time(data, chan->address, val2);
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mutex_unlock(&data->lock);
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return ret;
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case IIO_CHAN_INFO_RAW:
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if (chan->type != IIO_CURRENT || val2 != 0)
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return -EINVAL;
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mutex_lock(&data->lock);
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ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_HEATER_EN,
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val ? HDC100X_REG_CONFIG_HEATER_EN : 0);
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mutex_unlock(&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_info hdc100x_info = {
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.read_raw = hdc100x_read_raw,
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.write_raw = hdc100x_write_raw,
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.attrs = &hdc100x_attribute_group,
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.driver_module = THIS_MODULE,
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};
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static int hdc100x_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 hdc100x_data *data;
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if (!i2c_check_functionality(client->adapter,
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I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
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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->dev.parent = &client->dev;
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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 = &hdc100x_info;
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indio_dev->channels = hdc100x_channels;
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indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
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/* be sure we are in a known state */
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hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
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hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
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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 hdc100x_id[] = {
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{ "hdc100x", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, hdc100x_id);
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static struct i2c_driver hdc100x_driver = {
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.driver = {
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.name = "hdc100x",
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},
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.probe = hdc100x_probe,
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.id_table = hdc100x_id,
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};
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module_i2c_driver(hdc100x_driver);
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MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
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MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
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MODULE_LICENSE("GPL");
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