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path: root/drivers/iio/temperature/tmp117.c
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Diffstat (limited to 'drivers/iio/temperature/tmp117.c')
-rw-r--r--drivers/iio/temperature/tmp117.c185
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 000000000000..f9b8f2b570f6
--- /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");