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// SPDX-License-Identifier: GPL-2.0-only
/*
* Digital temperature sensor with integrated Non-volatile memory
* Copyright (c) 2021 Puranjay Mohan <puranjay12@gmail.com>
*
* Driver for the Texas Instruments TMP117 Temperature Sensor
* (7-bit I2C slave address (0x48 - 0x4B), changeable via ADD pins)
*
* Note: This driver assumes that the sensor has been calibrated beforehand.
*/
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/limits.h>
#include <linux/iio/iio.h>
#define TMP117_REG_TEMP 0x0
#define TMP117_REG_CFGR 0x1
#define TMP117_REG_HIGH_LIM 0x2
#define TMP117_REG_LOW_LIM 0x3
#define TMP117_REG_EEPROM_UL 0x4
#define TMP117_REG_EEPROM1 0x5
#define TMP117_REG_EEPROM2 0x6
#define TMP117_REG_TEMP_OFFSET 0x7
#define TMP117_REG_EEPROM3 0x8
#define TMP117_REG_DEVICE_ID 0xF
#define TMP117_RESOLUTION_10UC 78125
#define TMP117_DEVICE_ID 0x0117
#define MICRODEGREE_PER_10MILLIDEGREE 10000
struct tmp117_data {
struct i2c_client *client;
s16 calibbias;
};
static int tmp117_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *channel, int *val,
int *val2, long mask)
{
struct tmp117_data *data = iio_priv(indio_dev);
s32 ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = i2c_smbus_read_word_swapped(data->client,
TMP117_REG_TEMP);
if (ret < 0)
return ret;
*val = sign_extend32(ret, 15);
return IIO_VAL_INT;
case IIO_CHAN_INFO_CALIBBIAS:
ret = i2c_smbus_read_word_swapped(data->client,
TMP117_REG_TEMP_OFFSET);
if (ret < 0)
return ret;
*val = sign_extend32(ret, 15);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
/*
* Conversion from 10s of uC to mC
* as IIO reports temperature in mC
*/
*val = TMP117_RESOLUTION_10UC / MICRODEGREE_PER_10MILLIDEGREE;
*val2 = (TMP117_RESOLUTION_10UC %
MICRODEGREE_PER_10MILLIDEGREE) * 100;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
static int tmp117_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *channel, int val,
int val2, long mask)
{
struct tmp117_data *data = iio_priv(indio_dev);
s16 off;
switch (mask) {
case IIO_CHAN_INFO_CALIBBIAS:
off = clamp_t(int, val, S16_MIN, S16_MAX);
if (off == data->calibbias)
return 0;
data->calibbias = off;
return i2c_smbus_write_word_swapped(data->client,
TMP117_REG_TEMP_OFFSET, off);
default:
return -EINVAL;
}
}
static const struct iio_chan_spec tmp117_channels[] = {
{
.type = IIO_TEMP,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_CALIBBIAS) | BIT(IIO_CHAN_INFO_SCALE),
},
};
static const struct iio_info tmp117_info = {
.read_raw = tmp117_read_raw,
.write_raw = tmp117_write_raw,
};
static int tmp117_identify(struct i2c_client *client)
{
int dev_id;
dev_id = i2c_smbus_read_word_swapped(client, TMP117_REG_DEVICE_ID);
if (dev_id < 0)
return dev_id;
if (dev_id != TMP117_DEVICE_ID) {
dev_err(&client->dev, "TMP117 not found\n");
return -ENODEV;
}
return 0;
}
static int tmp117_probe(struct i2c_client *client)
{
struct tmp117_data *data;
struct iio_dev *indio_dev;
int ret;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
return -EOPNOTSUPP;
ret = tmp117_identify(client);
if (ret < 0)
return ret;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
data->client = client;
data->calibbias = 0;
indio_dev->name = "tmp117";
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &tmp117_info;
indio_dev->channels = tmp117_channels;
indio_dev->num_channels = ARRAY_SIZE(tmp117_channels);
return devm_iio_device_register(&client->dev, indio_dev);
}
static const struct of_device_id tmp117_of_match[] = {
{ .compatible = "ti,tmp117", },
{ }
};
MODULE_DEVICE_TABLE(of, tmp117_of_match);
static const struct i2c_device_id tmp117_id[] = {
{ "tmp117", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, tmp117_id);
static struct i2c_driver tmp117_driver = {
.driver = {
.name = "tmp117",
.of_match_table = tmp117_of_match,
},
.probe_new = tmp117_probe,
.id_table = tmp117_id,
};
module_i2c_driver(tmp117_driver);
MODULE_AUTHOR("Puranjay Mohan <puranjay12@gmail.com>");
MODULE_DESCRIPTION("TI TMP117 Temperature sensor driver");
MODULE_LICENSE("GPL");
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