diff options
Diffstat (limited to 'drivers/iio/temperature/tmp117.c')
| -rw-r--r-- | drivers/iio/temperature/tmp117.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/drivers/iio/temperature/tmp117.c b/drivers/iio/temperature/tmp117.c new file mode 100644 index 000000000..f9b8f2b57 --- /dev/null +++ b/drivers/iio/temperature/tmp117.c @@ -0,0 +1,185 @@ +// 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"); |