iio: temperature: add driver support for ti tmp117

TMP117 is a Digital temperature sensor with integrated Non-Volatile memory.
Add support for tmp117 driver in iio subsystem.

Datasheet: https://www.ti.com/lit/gpn/tmp117
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20210407182147.77221-3-puranjay12@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/MAINTAINERS b/MAINTAINERS
index 008fcad..f6191b0 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18094,6 +18094,13 @@ F:     Documentation/devicetree/bindings/hwmon/ti,tps23861.yaml
 F:     Documentation/hwmon/tps23861.rst
 F:     drivers/hwmon/tps23861.c
 
+TEXAS INSTRUMENTS' TMP117 TEMPERATURE SENSOR DRIVER
+M:     Puranjay Mohan <puranjay12@gmail.com>
+L:     linux-iio@vger.kernel.org
+S:     Supported
+F:     Documentation/devicetree/bindings/iio/temperature/ti,tmp117.yaml
+F:     drivers/iio/temperature/tmp117.c
+
 THANKO'S RAREMONO AM/FM/SW RADIO RECEIVER USB DRIVER
 M:     Hans Verkuil <hverkuil@xs4all.nl>
 L:     linux-media@vger.kernel.org

diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
index 4df6008..f20ae3c 100644 (file)
--- a/drivers/iio/temperature/Kconfig
+++ b/drivers/iio/temperature/Kconfig
@@ -96,6 +96,16 @@ config TMP007
          This driver can also be built as a module. If so, the module will
          be called tmp007.
 
+config TMP117
+       tristate "TMP117 Digital temperature sensor with integrated NV memory"
+       depends on I2C
+       help
+         If you say yes here you get support for the Texas Instruments
+         TMP117 Digital temperature sensor with integrated NV memory.
+
+         This driver can also be built as a module. If so, the module will
+         be called tmp117.
+
 config TSYS01
        tristate "Measurement Specialties TSYS01 temperature sensor using I2C bus connection"
        depends on I2C

diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
index 90c1131..e3392c4 100644 (file)
--- a/drivers/iio/temperature/Makefile
+++ b/drivers/iio/temperature/Makefile
@@ -12,5 +12,6 @@ obj-$(CONFIG_MLX90614) += mlx90614.o
 obj-$(CONFIG_MLX90632) += mlx90632.o
 obj-$(CONFIG_TMP006) += tmp006.o
 obj-$(CONFIG_TMP007) += tmp007.o
+obj-$(CONFIG_TMP117) += tmp117.o
 obj-$(CONFIG_TSYS01) += tsys01.o
 obj-$(CONFIG_TSYS02D) += tsys02d.o

diff --git a/drivers/iio/temperature/tmp117.c b/drivers/iio/temperature/tmp117.c
new file mode 100644 (file)
index 0000000..f9b8f2b
--- /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");