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235 lines
5.5 KiB
235 lines
5.5 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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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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* 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/mod_devicetable.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->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 = 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 <[email protected]>"); |
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MODULE_AUTHOR("Ludovic Tancerel <[email protected]>"); |
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MODULE_LICENSE("GPL v2");
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