![Jonathan Cameron](/assets/img/avatar_default.png)
The equivalent of this is now done via macro magic when the relevant register call is made. The actual structure elements will shortly go away. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
237 lines
5.5 KiB
C
237 lines
5.5 KiB
C
/*
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* tsys01.c - Support for Measurement-Specialties tsys01 temperature sensor
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*
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* Copyright (c) 2015 Measurement-Specialties
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*
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* Licensed under the GPL-2.
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*
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* Datasheet:
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* http://www.meas-spec.com/downloads/TSYS01_Digital_Temperature_Sensor.pdf
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*/
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include <linux/device.h>
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#include <linux/mutex.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/stat.h>
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#include "../common/ms_sensors/ms_sensors_i2c.h"
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/* TSYS01 Commands */
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#define TSYS01_RESET 0x1E
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#define TSYS01_CONVERSION_START 0x48
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#define TSYS01_ADC_READ 0x00
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#define TSYS01_PROM_READ 0xA0
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#define TSYS01_PROM_WORDS_NB 8
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struct tsys01_dev {
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void *client;
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struct mutex lock; /* lock during conversion */
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int (*reset)(void *cli, u8 cmd, unsigned int delay);
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int (*convert_and_read)(void *cli, u8 conv, u8 rd,
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unsigned int delay, u32 *adc);
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int (*read_prom_word)(void *cli, int cmd, u16 *word);
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u16 prom[TSYS01_PROM_WORDS_NB];
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};
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/* Multiplication coefficients for temperature computation */
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static const int coeff_mul[] = { -1500000, 1000000, -2000000,
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4000000, -2000000 };
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static int tsys01_read_temperature(struct iio_dev *indio_dev,
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s32 *temperature)
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{
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int ret, i;
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u32 adc;
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s64 temp = 0;
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struct tsys01_dev *dev_data = iio_priv(indio_dev);
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mutex_lock(&dev_data->lock);
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ret = dev_data->convert_and_read(dev_data->client,
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TSYS01_CONVERSION_START,
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TSYS01_ADC_READ, 9000, &adc);
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mutex_unlock(&dev_data->lock);
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if (ret)
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return ret;
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adc >>= 8;
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/* Temperature algorithm */
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for (i = 4; i > 0; i--) {
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temp += coeff_mul[i] *
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(s64)dev_data->prom[5 - i];
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temp *= (s64)adc;
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temp = div64_s64(temp, 100000);
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}
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temp *= 10;
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temp += coeff_mul[0] * (s64)dev_data->prom[5];
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temp = div64_s64(temp, 100000);
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*temperature = temp;
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return 0;
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}
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static int tsys01_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;
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s32 temperature;
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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 = tsys01_read_temperature(indio_dev, &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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default:
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return -EINVAL;
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}
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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 tsys01_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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}
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};
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static const struct iio_info tsys01_info = {
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.read_raw = tsys01_read_raw,
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};
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static bool tsys01_crc_valid(u16 *n_prom)
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{
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u8 cnt;
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u8 sum = 0;
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for (cnt = 0; cnt < TSYS01_PROM_WORDS_NB; cnt++)
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sum += ((n_prom[0] >> 8) + (n_prom[0] & 0xFF));
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return (sum == 0);
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}
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static int tsys01_read_prom(struct iio_dev *indio_dev)
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{
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int i, ret;
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struct tsys01_dev *dev_data = iio_priv(indio_dev);
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char buf[7 * TSYS01_PROM_WORDS_NB + 1];
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char *ptr = buf;
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for (i = 0; i < TSYS01_PROM_WORDS_NB; i++) {
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ret = dev_data->read_prom_word(dev_data->client,
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TSYS01_PROM_READ + (i << 1),
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&dev_data->prom[i]);
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if (ret)
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return ret;
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ret = sprintf(ptr, "0x%04x ", dev_data->prom[i]);
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ptr += ret;
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}
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if (!tsys01_crc_valid(dev_data->prom)) {
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dev_err(&indio_dev->dev, "prom crc check error\n");
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return -ENODEV;
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}
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*ptr = 0;
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dev_info(&indio_dev->dev, "PROM coefficients : %s\n", buf);
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return 0;
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}
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static int tsys01_probe(struct iio_dev *indio_dev, struct device *dev)
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{
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int ret;
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struct tsys01_dev *dev_data = iio_priv(indio_dev);
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mutex_init(&dev_data->lock);
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indio_dev->info = &tsys01_info;
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indio_dev->name = dev->driver->name;
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indio_dev->dev.parent = dev;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = tsys01_channels;
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indio_dev->num_channels = ARRAY_SIZE(tsys01_channels);
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ret = dev_data->reset(dev_data->client, TSYS01_RESET, 3000);
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if (ret)
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return ret;
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ret = tsys01_read_prom(indio_dev);
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if (ret)
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return ret;
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return devm_iio_device_register(dev, indio_dev);
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}
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static int tsys01_i2c_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct tsys01_dev *dev_data;
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struct iio_dev *indio_dev;
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if (!i2c_check_functionality(client->adapter,
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I2C_FUNC_SMBUS_WORD_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->reset = ms_sensors_reset;
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dev_data->read_prom_word = ms_sensors_read_prom_word;
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dev_data->convert_and_read = ms_sensors_convert_and_read;
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i2c_set_clientdata(client, indio_dev);
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return tsys01_probe(indio_dev, &client->dev);
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}
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static const struct i2c_device_id tsys01_id[] = {
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{"tsys01", 0},
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{}
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};
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MODULE_DEVICE_TABLE(i2c, tsys01_id);
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static const struct of_device_id tsys01_of_match[] = {
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{ .compatible = "meas,tsys01", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, tsys01_of_match);
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static struct i2c_driver tsys01_driver = {
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.probe = tsys01_i2c_probe,
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.id_table = tsys01_id,
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.driver = {
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.name = "tsys01",
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.of_match_table = of_match_ptr(tsys01_of_match),
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},
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};
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module_i2c_driver(tsys01_driver);
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MODULE_DESCRIPTION("Measurement-Specialties tsys01 temperature 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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