Re: [PATCH 2/2] iio: temperature: add driver support for ti tmp117
From: Lars-Peter Clausen
Date: Fri Mar 19 2021 - 18:03:33 EST
On 3/19/21 9:30 PM, Puranjay Mohan wrote:
TMP117 is a Digital temperature sensor with integrated NV memory.
Add support for tmp117 driver in iio subsystem.
Datasheet:-https://www.ti.com/lit/gpn/tmp117
Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx>
Hi,
Thanks for the patch, this looks really good. I have a couple of small
comments inline.
And one general comment. What you have implemented as
IIO_CHAN_INFO_OFFSET should be IIO_CHAN_INFO_CALIBBIAS, since it is an
offset for calibration. The IIO_CHAN_INFO_OFFSET property on the other
hand is used to describe how to convert from raw data to SI units.
---
drivers/iio/temperature/Kconfig | 11 ++
drivers/iio/temperature/Makefile | 1 +
drivers/iio/temperature/tmp117.c | 196 +++++++++++++++++++++++++++++++
3 files changed, 208 insertions(+)
create mode 100644 drivers/iio/temperature/tmp117.c
diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
index 3f11ed870..200efc880 100644
--- a/drivers/iio/temperature/Kconfig
+++ b/drivers/iio/temperature/Kconfig
@@ -86,6 +86,17 @@ 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 e4e0bad5a..7f2a95ed2 100644
--- a/drivers/iio/temperature/Makefile
+++ b/drivers/iio/temperature/Makefile
@@ -10,6 +10,7 @@ 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-$(CONFIG_TSYS02D) += tsys02d.o
obj-$(CONFIG_LTC2983) += ltc2983.o
diff --git a/drivers/iio/temperature/tmp117.c b/drivers/iio/temperature/tmp117.c
new file mode 100644
index 000000000..15cdf590e
--- /dev/null
+++ b/drivers/iio/temperature/tmp117.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * tmp117.c - Digital temperature sensor with integrated NV memory
+ *
+ * Copyright (c) 2021 Puranjay Mohan <puranjay12@xxxxxxxxx>
+ *
+ * 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/delay.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/bitops.h>
+#include <linux/of.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
interrupt.h is for consumers, irq.h is for providers. Since this driver
is only a interrupt consumer you only need irq.h.
I believe bitops.h and delay.h are also not needed by this driver.
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.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_EEPROM3 0x7
+#define TMP117_REG_TEMP_OFFSET 0x7
You got register 0x7 twice here.
+#define TMP117_REG_EEPROM4 0x8
+#define TMP117_REG_DEVICE_ID 0xF
+
+#define TMP117_RESOLUTION 78125 /* in tens of uCelsius*/
+#define TMP117_RESOLUTION_DIV 10000000
+
+#define TMP117_DEVICE_ID 0x0117
+
+struct tmp117_data {
+ struct i2c_client *client;
+ struct mutex lock;
+};
+
+static int tmp117_read_reg(struct tmp117_data *data, u8 reg)
+{
+
Being pedantic: the newline at the top here and also in write_reg are
not needed.
+ return i2c_smbus_read_word_swapped(data->client, reg);
+}
+
+static int tmp117_write_reg(struct tmp117_data *data, u8 reg, int val)
+{
+
+ return i2c_smbus_write_word_swapped(data->client, reg, val);
+}
+
+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);
+ u16 tmp, off;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_PROCESSED:
+ tmp = tmp117_read_reg(data, TMP117_REG_TEMP);
+ *val = ((int16_t)tmp * (int32_t)TMP117_RESOLUTION) / 10000000;
+ *val2 = ((int16_t)tmp * (int32_t)TMP117_RESOLUTION) % 10000000;
Since this is a linear transform it would be better to report RAW
measurements and then provide the scale attribute for conversion,.
+ return IIO_VAL_INT_PLUS_MICRO;
+
+ case IIO_CHAN_INFO_OFFSET:
+ off = tmp117_read_reg(data, TMP117_REG_TEMP_OFFSET);
+ *val = ((int16_t)off * (int32_t)TMP117_RESOLUTION) / 10000000;
+ *val2 = ((int16_t)off * (int32_t)TMP117_RESOLUTION) % 10000000;
+ 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);
+ u16 off;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_OFFSET:
+ off = ((val * 10000000) + (val2 * 10))
+ / (int32_t)TMP117_RESOLUTION;
+ return tmp117_write_reg(data, 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_PROCESSED) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ },
+};
+
+static const struct iio_info tmp117_info = {
+ .read_raw = tmp117_read_raw,
+ .write_raw = tmp117_write_raw,
+};
+
+static bool 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 false;
+
+ return (dev_id == TMP117_DEVICE_ID);
+}
+
+static int tmp117_probe(struct i2c_client *client,
+ const struct i2c_device_id *tmp117_id)
+{
+ struct tmp117_data *data;
+ struct iio_dev *indio_dev;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
+ return -EOPNOTSUPP;
+
+ if (!tmp117_identify(client)) {
+ dev_err(&client->dev, "TMP117 not found\n");
+ return -ENODEV;
+ }
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
If you remove the remove() callback the i2c_set_clientdata() here can
also be removed.
+ data->client = client;
+ mutex_init(&data->lock);
+
+ indio_dev->dev.parent = &client->dev;
The parent assignment is no longer needed in the latest upstream kernel
since it happens in devm_iio_device_alloc().
+ 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 iio_device_register(indio_dev);
devm_iio_device_register(...) and then you can remove the the remove()
callback.
+}
+
[...]