[PATCH 0/2] Add driver for HTU31

[PATCH 0/2] Add driver for HTU31

[Andrei Lalaev]

This patch series adds support for HTU31 humidity and temperature
sensor.

Andrei Lalaev (2):
  hwmon: add driver for HTU31
  dt-bindings: hwmon: Add description for sensor HTU31

 .../devicetree/bindings/trivial-devices.yaml  |   2 +
 Documentation/hwmon/htu31.rst                 |  38 ++
 Documentation/hwmon/index.rst                 |   1 +
 drivers/hwmon/Kconfig                         |  11 +
 drivers/hwmon/Makefile                        |   1 +
 drivers/hwmon/htu31.c                         | 335 ++++++++++++++++++
 6 files changed, 388 insertions(+)
 create mode 100644 Documentation/hwmon/htu31.rst
 create mode 100644 drivers/hwmon/htu31.c

-- 
2.48.1

[PATCH 1/2] hwmon: add driver for HTU31

[Andrei Lalaev]

Add base support for HTU31 temperature and humidity sensor.

Besides temperature and humidity values, the driver also exports a 24-bit
serial number to sysfs.

Signed-off-by: Andrei Lalaev <andrey.lalaev@gmail.com>
---
 Documentation/hwmon/htu31.rst |  38 ++++
 Documentation/hwmon/index.rst |   1 +
 drivers/hwmon/Kconfig         |  11 ++
 drivers/hwmon/Makefile        |   1 +
 drivers/hwmon/htu31.c         | 335 ++++++++++++++++++++++++++++++++++
 5 files changed, 386 insertions(+)
 create mode 100644 Documentation/hwmon/htu31.rst
 create mode 100644 drivers/hwmon/htu31.c

diff --git a/Documentation/hwmon/htu31.rst b/Documentation/hwmon/htu31.rst
new file mode 100644
index 000000000000..a7a960e215ec
--- /dev/null
+++ b/Documentation/hwmon/htu31.rst
@@ -0,0 +1,38 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver HTU31
+====================
+
+Supported chips:
+
+  * Measurement Specialties HTU31
+
+    Prefix: 'htu31'
+
+    Addresses scanned: -
+
+    Datasheet: Publicly available from https://www.te.com/en/product-CAT-HSC0007.html
+
+Author:
+
+  - Andrei Lalaev <andrey.lalaev@gmail.com>
+
+Description
+-----------
+
+HTU31 is a humidity and temperature sensor.
+
+Supported temperature range is from -40 to 125 degrees Celsius.
+
+Communication with the device is performed via I2C protocol. Sensor's default address
+is 0x40.
+
+sysfs-Interface
+---------------
+
+=================== =================
+temp1_input:        temperature input
+humidity1_input:    humidity input
+serial_number:      serial number
+heater_enable:      heater control
+=================== =================
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 874f8fd26325..86f6f5e46b59 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -85,6 +85,7 @@ Hardware Monitoring Kernel Drivers
    hih6130
    hp-wmi-sensors
    hs3001
+   htu31
    ibmaem
    ibm-cffps
    ibmpowernv
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 4cbaba15d86e..e123e06ba352 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -789,6 +789,17 @@ config SENSORS_HS3001
 	  This driver can also be built as a module. If so, the module
 	  will be called hs3001.
 
+config SENSORS_HTU31
+	tristate "Measurement Specialties HTU31 humidity and temperature sensor"
+	depends on I2C
+	select CRC8
+	help
+	  If you say yes here you get support for the HTU31 humidity
+	  and temperature sensors.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called htu31.
+
 config SENSORS_IBMAEM
 	tristate "IBM Active Energy Manager temperature/power sensors and control"
 	select IPMI_SI
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index b7ef0f0562d3..02465d959d14 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -199,6 +199,7 @@ obj-$(CONFIG_SENSORS_SCH5636)	+= sch5636.o
 obj-$(CONFIG_SENSORS_SFCTEMP)	+= sfctemp.o
 obj-$(CONFIG_SENSORS_SG2042_MCU) += sg2042-mcu.o
 obj-$(CONFIG_SENSORS_SL28CPLD)	+= sl28cpld-hwmon.o
+obj-$(CONFIG_SENSORS_HTU31)	+= htu31.o
 obj-$(CONFIG_SENSORS_SHT15)	+= sht15.o
 obj-$(CONFIG_SENSORS_SHT21)	+= sht21.o
 obj-$(CONFIG_SENSORS_SHT3x)	+= sht3x.o
diff --git a/drivers/hwmon/htu31.c b/drivers/hwmon/htu31.c
new file mode 100644
index 000000000000..09f979a8db92
--- /dev/null
+++ b/drivers/hwmon/htu31.c
@@ -0,0 +1,335 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * The driver for Measurement Specialties HTU31 Temperature and Humidity sensor.
+ *
+ * Copyright (C) 2025
+ * Author: Andrei Lalaev <andrey.lalaev@gmail.com>
+ */
+
+#include <linux/array_size.h>
+#include <linux/cleanup.h>
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/module.h>
+
+#define HTU31_READ_TEMP_HUM_CMD	0x00
+#define HTU31_READ_SERIAL_CMD		0x0a
+#define HTU31_CONVERSION_CMD		0x5e
+#define HTU31_HEATER_OFF_CMD		0x02
+#define HTU31_HEATER_ON_CMD		0x04
+
+#define HTU31_TEMP_HUM_LEN		6
+
+/* Conversion time for the highest resolution */
+#define HTU31_HUMIDITY_CONV_TIME	10000 /* us */
+#define HTU31_TEMPERATURE_CONV_TIME	15000 /* us */
+
+#define HTU31_SERIAL_NUMBER_LEN	3
+#define HTU31_SERIAL_NUMBER_CRC_LEN	1
+#define HTU31_SERIAL_NUMBER_CRC_OFFSET	3
+
+#define HTU31_CRC8_INIT_VAL		0
+#define HTU31_CRC8_POLYNOMIAL		0x31
+DECLARE_CRC8_TABLE(htu31_crc8_table);
+
+struct htu31_data {
+	struct i2c_client *client;
+	struct mutex i2c_lock;
+	long wait_time;
+	long temperature;
+	long humidity;
+	u8 serial_number[HTU31_SERIAL_NUMBER_LEN];
+	bool heater_enable;
+};
+
+static long htu31_temp_to_millicelsius(long val)
+{
+	return -40000 + DIV_ROUND_CLOSEST(165000 * val, 65535);
+}
+
+static long htu31_relative_humidity(long val)
+{
+	return DIV_ROUND_CLOSEST(100000 * val, 65535);
+}
+
+static int htu31_data_fetch_command(struct htu31_data *data)
+{
+	struct i2c_client *client = data->client;
+	u8 conversion_on = HTU31_CONVERSION_CMD;
+	u8 read_data_cmd = HTU31_READ_TEMP_HUM_CMD;
+	u8 t_h_buf[HTU31_TEMP_HUM_LEN] = {};
+	struct i2c_msg msgs[] = {
+		{
+			.addr = client->addr,
+			.flags = 0,
+			.len = 1,
+			.buf = &read_data_cmd,
+		},
+		{
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = sizeof(t_h_buf),
+			.buf = t_h_buf,
+		},
+	};
+	int ret;
+	u8 crc;
+
+	guard(mutex)(&data->i2c_lock);
+
+	ret = i2c_master_send(client, &conversion_on, 1);
+	if (ret != 1) {
+		ret = ret < 0 ? ret : -EIO;
+		dev_err(&client->dev,
+			"Conversion command is failed. Error code: %d\n", ret);
+		return ret;
+	}
+
+	fsleep(data->wait_time);
+
+	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	if (ret != ARRAY_SIZE(msgs)) {
+		ret = ret < 0 ? ret : -EIO;
+		dev_err(&client->dev,
+			"T&H command is failed. Error code: %d\n", ret);
+		return ret;
+	}
+
+	crc = crc8(htu31_crc8_table, &t_h_buf[0], 2, HTU31_CRC8_INIT_VAL);
+	if (crc != t_h_buf[2]) {
+		dev_err(&client->dev, "Temperature CRC mismatch\n");
+		return -EIO;
+	}
+
+	crc = crc8(htu31_crc8_table, &t_h_buf[3], 2, HTU31_CRC8_INIT_VAL);
+	if (crc != t_h_buf[5]) {
+		dev_err(&client->dev, "Humidity CRC mismatch\n");
+		return -EIO;
+	}
+
+	data->temperature = htu31_temp_to_millicelsius(be16_to_cpup((__be16 *) &t_h_buf[0]));
+	data->humidity = htu31_relative_humidity(be16_to_cpup((__be16 *) &t_h_buf[3]));
+
+	return 0;
+}
+
+static umode_t htu31_is_visible(const void *data, enum hwmon_sensor_types type,
+		u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_temp:
+	case hwmon_humidity:
+		return 0444;
+	default:
+		return 0;
+	}
+}
+
+static int htu31_read(struct device *dev, enum hwmon_sensor_types type,
+		u32 attr, int channel, long *val)
+{
+	struct htu31_data *data = dev_get_drvdata(dev);
+	int ret;
+
+	ret = htu31_data_fetch_command(data);
+
+	if (ret < 0)
+		return ret;
+
+	switch (type) {
+	case hwmon_temp:
+		if (attr != hwmon_temp_input)
+			return -EINVAL;
+
+		*val = data->temperature;
+		break;
+	case hwmon_humidity:
+		if (attr != hwmon_humidity_input)
+			return -EINVAL;
+
+		*val = data->humidity;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int serial_number_populate(struct htu31_data *data)
+{
+	struct i2c_client *client = data->client;
+	u8 read_sn_cmd = HTU31_READ_SERIAL_CMD;
+	u8 sn_buf[HTU31_SERIAL_NUMBER_LEN + HTU31_SERIAL_NUMBER_CRC_LEN];
+	struct i2c_msg msgs[] = {
+		{
+			.addr = client->addr,
+			.flags = 0,
+			.len = 1,
+			.buf = &read_sn_cmd,
+		},
+		{
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = sizeof(sn_buf),
+			.buf = sn_buf,
+		},
+	};
+	int ret;
+	u8 crc;
+
+	guard(mutex)(&data->i2c_lock);
+
+	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	if (ret < 0)
+		return -EIO;
+
+	crc = crc8(htu31_crc8_table, sn_buf, HTU31_SERIAL_NUMBER_LEN, HTU31_CRC8_INIT_VAL);
+	if (crc != sn_buf[HTU31_SERIAL_NUMBER_CRC_OFFSET]) {
+		dev_err(&client->dev, "Serial number CRC mismatch\n");
+		return -EIO;
+	}
+
+	memcpy(data->serial_number, sn_buf, HTU31_SERIAL_NUMBER_LEN);
+
+	return 0;
+}
+
+static ssize_t heater_enable_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	struct htu31_data *data = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", data->heater_enable);
+}
+
+static ssize_t heater_enable_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf,
+				   size_t count)
+{
+	struct htu31_data *data = dev_get_drvdata(dev);
+	u8 heater_cmd;
+	bool status;
+	int ret;
+
+	ret = kstrtobool(buf, &status);
+	if (ret)
+		return ret;
+
+	heater_cmd = status ? HTU31_HEATER_ON_CMD : HTU31_HEATER_OFF_CMD;
+
+	guard(mutex)(&data->i2c_lock);
+
+	ret = i2c_master_send(data->client, &heater_cmd, 1);
+	if (ret < 0)
+		return -EIO;
+
+	data->heater_enable = status;
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(heater_enable);
+
+static ssize_t serial_number_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	struct htu31_data *data = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%X%X%X\n", data->serial_number[0],
+					   data->serial_number[1],
+					   data->serial_number[2]);
+}
+
+static DEVICE_ATTR_RO(serial_number);
+
+static struct attribute *htu31_attrs[] = {
+	&dev_attr_heater_enable.attr,
+	&dev_attr_serial_number.attr,
+	NULL,
+};
+
+ATTRIBUTE_GROUPS(htu31);
+
+static const struct hwmon_channel_info * const htu31_info[] = {
+	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+	HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT),
+	NULL,
+};
+
+static const struct hwmon_ops htu31_hwmon_ops = {
+	.is_visible = htu31_is_visible,
+	.read = htu31_read,
+};
+
+static const struct hwmon_chip_info htu31_chip_info = {
+	.info = htu31_info,
+	.ops = &htu31_hwmon_ops,
+};
+
+static int htu31_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device *hwmon_dev;
+	struct htu31_data *data;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+	data->wait_time = HTU31_TEMPERATURE_CONV_TIME + HTU31_HUMIDITY_CONV_TIME;
+
+	mutex_init(&data->i2c_lock);
+
+	crc8_populate_msb(htu31_crc8_table, HTU31_CRC8_POLYNOMIAL);
+
+	if (serial_number_populate(data)) {
+		dev_err(dev, "Failed to read serial number\n");
+		return -EIO;
+	}
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev,
+							 client->name,
+							 data,
+							 &htu31_chip_info,
+							 htu31_groups);
+
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id htu31_id[] = {
+	{ "htu31" },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, htu31_id);
+
+#if IS_ENABLED(CONFIG_OF)
+static const struct of_device_id htu31_of_match[] = {
+	{ .compatible = "meas,htu31" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, htu31_of_match);
+#endif
+
+static struct i2c_driver htu31_driver = {
+	.driver = {
+		.name = "htu31",
+		.of_match_table = of_match_ptr(htu31_of_match),
+	},
+	.probe = htu31_probe,
+	.id_table = htu31_id,
+};
+module_i2c_driver(htu31_driver);
+
+MODULE_AUTHOR("Andrei Lalaev <andrey.lalaev@gmail.com>");
+MODULE_DESCRIPTION("HTU31 Temperature and Humidity sensor driver");
+MODULE_VERSION("1.0");
+MODULE_LICENSE("GPL");
-- 
2.48.1

Re: [PATCH 1/2] hwmon: add driver for HTU31

[Krzysztof Kozlowski]

On Thu, Jan 23, 2025 at 09:25:06PM +0100, Andrei Lalaev wrote:
>     ibmpowernv
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 4cbaba15d86e..e123e06ba352 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -789,6 +789,17 @@ config SENSORS_HS3001
>  	  This driver can also be built as a module. If so, the module
>  	  will be called hs3001.
>  

Looks like you add here stray spaces.

> +config SENSORS_HTU31
> +	tristate "Measurement Specialties HTU31 humidity and temperature sensor"
> +	depends on I2C
> +	select CRC8
> +	help
> +	  If you say yes here you get support for the HTU31 humidity
> +	  and temperature sensors.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called htu31.
> +
>  config SENSORS_IBMAEM
>  	tristate "IBM Active Energy Manager temperature/power sensors and control"
>  	select IPMI_SI
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index b7ef0f0562d3..02465d959d14 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -199,6 +199,7 @@ obj-$(CONFIG_SENSORS_SCH5636)	+= sch5636.o
>  obj-$(CONFIG_SENSORS_SFCTEMP)	+= sfctemp.o
>  obj-$(CONFIG_SENSORS_SG2042_MCU) += sg2042-mcu.o
>  obj-$(CONFIG_SENSORS_SL28CPLD)	+= sl28cpld-hwmon.o
> +obj-$(CONFIG_SENSORS_HTU31)	+= htu31.o
>  obj-$(CONFIG_SENSORS_SHT15)	+= sht15.o
>  obj-$(CONFIG_SENSORS_SHT21)	+= sht21.o
>  obj-$(CONFIG_SENSORS_SHT3x)	+= sht3x.o
> diff --git a/drivers/hwmon/htu31.c b/drivers/hwmon/htu31.c
> new file mode 100644
> index 000000000000..09f979a8db92
> --- /dev/null
> +++ b/drivers/hwmon/htu31.c
> @@ -0,0 +1,335 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * The driver for Measurement Specialties HTU31 Temperature and Humidity sensor.
> + *
> + * Copyright (C) 2025
> + * Author: Andrei Lalaev <andrey.lalaev@gmail.com>
> + */
> +
> +#include <linux/array_size.h>
> +#include <linux/cleanup.h>
> +#include <linux/crc8.h>
> +#include <linux/delay.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +
> +#define HTU31_READ_TEMP_HUM_CMD	0x00
> +#define HTU31_READ_SERIAL_CMD		0x0a
> +#define HTU31_CONVERSION_CMD		0x5e
> +#define HTU31_HEATER_OFF_CMD		0x02
> +#define HTU31_HEATER_ON_CMD		0x04
> +
> +#define HTU31_TEMP_HUM_LEN		6
> +
> +/* Conversion time for the highest resolution */
> +#define HTU31_HUMIDITY_CONV_TIME	10000 /* us */
> +#define HTU31_TEMPERATURE_CONV_TIME	15000 /* us */
> +
> +#define HTU31_SERIAL_NUMBER_LEN	3
> +#define HTU31_SERIAL_NUMBER_CRC_LEN	1
> +#define HTU31_SERIAL_NUMBER_CRC_OFFSET	3
> +
> +#define HTU31_CRC8_INIT_VAL		0
> +#define HTU31_CRC8_POLYNOMIAL		0x31
> +DECLARE_CRC8_TABLE(htu31_crc8_table);
> +
> +struct htu31_data {
> +	struct i2c_client *client;
> +	struct mutex i2c_lock;

What is the lock guarding? See checkpatch below. What's confusing is
that you call it I2C but it also covers some memcpy operations and this
rtcuture, so much wider scope. Be detaile when fixing checkpatch
warning.

Please run scripts/checkpatch.pl and fix reported warnings. After that,
run also 'scripts/checkpatch.pl --strict' and (probably) fix more
warnings. Some warnings can be ignored, especially from --strict run,
but the code here looks like it needs a fix. Feel free to get in touch
if the warning is not clear.


> +	long wait_time;
> +	long temperature;
> +	long humidity;
> +	u8 serial_number[HTU31_SERIAL_NUMBER_LEN];
> +	bool heater_enable;
> +};
> +
> +static long htu31_temp_to_millicelsius(long val)
> +{
> +	return -40000 + DIV_ROUND_CLOSEST(165000 * val, 65535);
> +}
> +
> +static long htu31_relative_humidity(long val)
> +{
> +	return DIV_ROUND_CLOSEST(100000 * val, 65535);
> +}
> +
> +static int htu31_data_fetch_command(struct htu31_data *data)
> +{
> +	struct i2c_client *client = data->client;
> +	u8 conversion_on = HTU31_CONVERSION_CMD;
> +	u8 read_data_cmd = HTU31_READ_TEMP_HUM_CMD;
> +	u8 t_h_buf[HTU31_TEMP_HUM_LEN] = {};
> +	struct i2c_msg msgs[] = {
> +		{
> +			.addr = client->addr,
> +			.flags = 0,
> +			.len = 1,
> +			.buf = &read_data_cmd,
> +		},
> +		{
> +			.addr = client->addr,
> +			.flags = I2C_M_RD,
> +			.len = sizeof(t_h_buf),
> +			.buf = t_h_buf,
> +		},
> +	};
> +	int ret;
> +	u8 crc;
> +
> +	guard(mutex)(&data->i2c_lock);
> +
> +	ret = i2c_master_send(client, &conversion_on, 1);
> +	if (ret != 1) {
> +		ret = ret < 0 ? ret : -EIO;
> +		dev_err(&client->dev,
> +			"Conversion command is failed. Error code: %d\n", ret);
> +		return ret;
> +	}
> +
> +	fsleep(data->wait_time);
> +
> +	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
> +	if (ret != ARRAY_SIZE(msgs)) {
> +		ret = ret < 0 ? ret : -EIO;
> +		dev_err(&client->dev,
> +			"T&H command is failed. Error code: %d\n", ret);
> +		return ret;
> +	}
> +
> +	crc = crc8(htu31_crc8_table, &t_h_buf[0], 2, HTU31_CRC8_INIT_VAL);
> +	if (crc != t_h_buf[2]) {
> +		dev_err(&client->dev, "Temperature CRC mismatch\n");
> +		return -EIO;
> +	}
> +
> +	crc = crc8(htu31_crc8_table, &t_h_buf[3], 2, HTU31_CRC8_INIT_VAL);
> +	if (crc != t_h_buf[5]) {
> +		dev_err(&client->dev, "Humidity CRC mismatch\n");
> +		return -EIO;
> +	}
> +
> +	data->temperature = htu31_temp_to_millicelsius(be16_to_cpup((__be16 *) &t_h_buf[0]));
> +	data->humidity = htu31_relative_humidity(be16_to_cpup((__be16 *) &t_h_buf[3]));
> +
> +	return 0;
> +}
> +
> +static umode_t htu31_is_visible(const void *data, enum hwmon_sensor_types type,
> +		u32 attr, int channel)
> +{
> +	switch (type) {
> +	case hwmon_temp:
> +	case hwmon_humidity:
> +		return 0444;
> +	default:
> +		return 0;
> +	}
> +}
> +
> +static int htu31_read(struct device *dev, enum hwmon_sensor_types type,
> +		u32 attr, int channel, long *val)
> +{
> +	struct htu31_data *data = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = htu31_data_fetch_command(data);
> +
> +	if (ret < 0)
> +		return ret;
> +
> +	switch (type) {
> +	case hwmon_temp:
> +		if (attr != hwmon_temp_input)
> +			return -EINVAL;
> +
> +		*val = data->temperature;
> +		break;
> +	case hwmon_humidity:
> +		if (attr != hwmon_humidity_input)
> +			return -EINVAL;
> +
> +		*val = data->humidity;
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int serial_number_populate(struct htu31_data *data)

htu31_read_serial_number(...)


> +{
> +	struct i2c_client *client = data->client;
> +	u8 read_sn_cmd = HTU31_READ_SERIAL_CMD;
> +	u8 sn_buf[HTU31_SERIAL_NUMBER_LEN + HTU31_SERIAL_NUMBER_CRC_LEN];
> +	struct i2c_msg msgs[] = {
> +		{
> +			.addr = client->addr,
> +			.flags = 0,
> +			.len = 1,
> +			.buf = &read_sn_cmd,
> +		},
> +		{
> +			.addr = client->addr,
> +			.flags = I2C_M_RD,
> +			.len = sizeof(sn_buf),
> +			.buf = sn_buf,
> +		},
> +	};
> +	int ret;
> +	u8 crc;
> +
> +	guard(mutex)(&data->i2c_lock);
> +
> +	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
> +	if (ret < 0)
> +		return -EIO;
> +
> +	crc = crc8(htu31_crc8_table, sn_buf, HTU31_SERIAL_NUMBER_LEN, HTU31_CRC8_INIT_VAL);
> +	if (crc != sn_buf[HTU31_SERIAL_NUMBER_CRC_OFFSET]) {
> +		dev_err(&client->dev, "Serial number CRC mismatch\n");
> +		return -EIO;
> +	}
> +
> +	memcpy(data->serial_number, sn_buf, HTU31_SERIAL_NUMBER_LEN);

...

> +#if IS_ENABLED(CONFIG_OF)
> +static const struct of_device_id htu31_of_match[] = {
> +	{ .compatible = "meas,htu31" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, htu31_of_match);
> +#endif
> +
> +static struct i2c_driver htu31_driver = {
> +	.driver = {
> +		.name = "htu31",
> +		.of_match_table = of_match_ptr(htu31_of_match),
> +	},
> +	.probe = htu31_probe,
> +	.id_table = htu31_id,
> +};
> +module_i2c_driver(htu31_driver);
> +
> +MODULE_AUTHOR("Andrei Lalaev <andrey.lalaev@gmail.com>");
> +MODULE_DESCRIPTION("HTU31 Temperature and Humidity sensor driver");
> +MODULE_VERSION("1.0");

Drop version. Linux kernel defines the version.

Best regards,
Krzysztof

Re: [PATCH 1/2] hwmon: add driver for HTU31

[Andrei Lalaev]

On 24.01.2025 09:31, Krzysztof Kozlowski wrote:
> On Thu, Jan 23, 2025 at 09:25:06PM +0100, Andrei Lalaev wrote:
>>     ibmpowernv
>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
>> index 4cbaba15d86e..e123e06ba352 100644
>> --- a/drivers/hwmon/Kconfig
>> +++ b/drivers/hwmon/Kconfig
>> @@ -789,6 +789,17 @@ config SENSORS_HS3001
>>  	  This driver can also be built as a module. If so, the module
>>  	  will be called hs3001.
>>  
> 
> Looks like you add here stray spaces.
> 

Could you please explain what you mean? I see only 1 tab and 2 spaces right after it,
but they were here even before my patch.


-- 
Best regards,
Andrei Lalaev

Re: [PATCH 1/2] hwmon: add driver for HTU31

[Krzysztof Kozlowski]

On 24/01/2025 15:56, Andrei Lalaev wrote:
> On 24.01.2025 09:31, Krzysztof Kozlowski wrote:
>> On Thu, Jan 23, 2025 at 09:25:06PM +0100, Andrei Lalaev wrote:
>>>     ibmpowernv
>>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
>>> index 4cbaba15d86e..e123e06ba352 100644
>>> --- a/drivers/hwmon/Kconfig
>>> +++ b/drivers/hwmon/Kconfig
>>> @@ -789,6 +789,17 @@ config SENSORS_HS3001
>>>  	  This driver can also be built as a module. If so, the module
>>>  	  will be called hs3001.
>>>  
>>
>> Looks like you add here stray spaces.
>>
> 
> Could you please explain what you mean? I see only 1 tab and 2 spaces right after it,
> but they were here even before my patch.


Diff in mutt looked like having stray spaces added in this hunk. Exactly
that line I commented under, not in some other place. There was no tab
and 2 spaces.

If you double checked and are sure there is no stray space, then fine.
Could be just mutt....

Best regards,
Krzysztof

Re: [PATCH 1/2] hwmon: add driver for HTU31

[Christophe JAILLET]

Le 23/01/2025 à 21:25, Andrei Lalaev a écrit :
> Add base support for HTU31 temperature and humidity sensor.
> 
> Besides temperature and humidity values, the driver also exports a 24-bit
> serial number to sysfs.
> 
> Signed-off-by: Andrei Lalaev <andrey.lalaev@gmail.com>
> ---

...

> +static int htu31_read(struct device *dev, enum hwmon_sensor_types type,
> +		u32 attr, int channel, long *val)
> +{
> +	struct htu31_data *data = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = htu31_data_fetch_command(data);
> +

Unneeded empty line.

> +	if (ret < 0)
> +		return ret;
> +
> +	switch (type) {
> +	case hwmon_temp:
> +		if (attr != hwmon_temp_input)
> +			return -EINVAL;
> +
> +		*val = data->temperature;
> +		break;
> +	case hwmon_humidity:
> +		if (attr != hwmon_humidity_input)
> +			return -EINVAL;
> +
> +		*val = data->humidity;
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int serial_number_populate(struct htu31_data *data)
> +{
> +	struct i2c_client *client = data->client;
> +	u8 read_sn_cmd = HTU31_READ_SERIAL_CMD;
> +	u8 sn_buf[HTU31_SERIAL_NUMBER_LEN + HTU31_SERIAL_NUMBER_CRC_LEN];
> +	struct i2c_msg msgs[] = {
> +		{
> +			.addr = client->addr,
> +			.flags = 0,
> +			.len = 1,
> +			.buf = &read_sn_cmd,
> +		},
> +		{
> +			.addr = client->addr,
> +			.flags = I2C_M_RD,
> +			.len = sizeof(sn_buf),
> +			.buf = sn_buf,
> +		},
> +	};
> +	int ret;
> +	u8 crc;
> +
> +	guard(mutex)(&data->i2c_lock);
> +
> +	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
> +	if (ret < 0)
> +		return -EIO;

Why not return ret?

> +
> +	crc = crc8(htu31_crc8_table, sn_buf, HTU31_SERIAL_NUMBER_LEN, HTU31_CRC8_INIT_VAL);
> +	if (crc != sn_buf[HTU31_SERIAL_NUMBER_CRC_OFFSET]) {
> +		dev_err(&client->dev, "Serial number CRC mismatch\n");
> +		return -EIO;
> +	}
> +
> +	memcpy(data->serial_number, sn_buf, HTU31_SERIAL_NUMBER_LEN);
> +
> +	return 0;
> +}

...

> +static ssize_t heater_enable_store(struct device *dev,
> +				   struct device_attribute *attr,
> +				   const char *buf,
> +				   size_t count)
> +{
> +	struct htu31_data *data = dev_get_drvdata(dev);
> +	u8 heater_cmd;
> +	bool status;
> +	int ret;
> +
> +	ret = kstrtobool(buf, &status);
> +	if (ret)
> +		return ret;
> +
> +	heater_cmd = status ? HTU31_HEATER_ON_CMD : HTU31_HEATER_OFF_CMD;
> +
> +	guard(mutex)(&data->i2c_lock);
> +
> +	ret = i2c_master_send(data->client, &heater_cmd, 1);
> +	if (ret < 0)
> +		return -EIO;

Why not return ret?

> +
> +	data->heater_enable = status;
> +
> +	return count;
> +}
> +
> +static DEVICE_ATTR_RW(heater_enable);
> +
> +static ssize_t serial_number_show(struct device *dev,
> +				  struct device_attribute *attr,
> +				  char *buf)
> +{
> +	struct htu31_data *data = dev_get_drvdata(dev);
> +
> +	return sysfs_emit(buf, "%X%X%X\n", data->serial_number[0],
> +					   data->serial_number[1],
> +					   data->serial_number[2]);
> +}
> +
> +static DEVICE_ATTR_RO(serial_number);
> +
> +static struct attribute *htu31_attrs[] = {
> +	&dev_attr_heater_enable.attr,
> +	&dev_attr_serial_number.attr,
> +	NULL,

No need for trailing comma after a terminator

> +};
> +
> +ATTRIBUTE_GROUPS(htu31);
> +
> +static const struct hwmon_channel_info * const htu31_info[] = {
> +	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
> +	HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT),
> +	NULL,

No need for trailing comma after a terminator

> +};

...

> +static int htu31_probe(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct device *hwmon_dev;
> +	struct htu31_data *data;
> +
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->client = client;
> +	data->wait_time = HTU31_TEMPERATURE_CONV_TIME + HTU31_HUMIDITY_CONV_TIME;
> +
> +	mutex_init(&data->i2c_lock);

Maybe devm_mutex_init()?

> +
> +	crc8_populate_msb(htu31_crc8_table, HTU31_CRC8_POLYNOMIAL);
> +
> +	if (serial_number_populate(data)) {

Maybe:
     ret = serial_number_populate(data);
     if (ret) {
         ...
         return ret;
     }

> +		dev_err(dev, "Failed to read serial number\n");
> +		return -EIO;
> +	}
> +
> +	hwmon_dev = devm_hwmon_device_register_with_info(dev,
> +							 client->name,
> +							 data,
> +							 &htu31_chip_info,
> +							 htu31_groups);
> +
> +	return PTR_ERR_OR_ZERO(hwmon_dev);
> +}
> +
> +static const struct i2c_device_id htu31_id[] = {
> +	{ "htu31" },
> +	{ },

No need for trailing comma after a terminator

> +};
> +MODULE_DEVICE_TABLE(i2c, htu31_id);
> +
> +#if IS_ENABLED(CONFIG_OF)
> +static const struct of_device_id htu31_of_match[] = {
> +	{ .compatible = "meas,htu31" },
> +	{ },

No need for trailing comma after a terminator

> +};
> +MODULE_DEVICE_TABLE(of, htu31_of_match);

...

CJ

[PATCH 2/2] dt-bindings: hwmon: Add description for sensor HTU31

[Andrei Lalaev]

Add trivial binding for HTU31 Temperature and Humidity sensor.

Signed-off-by: Andrei Lalaev <andrey.lalaev@gmail.com>
---
 Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/trivial-devices.yaml b/Documentation/devicetree/bindings/trivial-devices.yaml
index 6bdcd055e763..294e8f9bfb4a 100644
--- a/Documentation/devicetree/bindings/trivial-devices.yaml
+++ b/Documentation/devicetree/bindings/trivial-devices.yaml
@@ -189,6 +189,8 @@ properties:
           - mcube,mc3230
             # Measurement Specialities I2C temperature and humidity sensor
           - meas,htu21
+            # Measurement Specialities I2C temperature and humidity sensor
+          - meas,htu31
             # Measurement Specialities I2C pressure and temperature sensor
           - meas,ms5637
             # Measurement Specialities I2C pressure and temperature sensor
-- 
2.48.1

Re: [PATCH 2/2] dt-bindings: hwmon: Add description for sensor HTU31

[Krzysztof Kozlowski]

On Thu, Jan 23, 2025 at 09:25:07PM +0100, Andrei Lalaev wrote:
> Add trivial binding for HTU31 Temperature and Humidity sensor.
> 
> Signed-off-by: Andrei Lalaev <andrey.lalaev@gmail.com>
> ---
>  Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
>  1 file changed, 2 insertions(+)

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>


---

<form letter>
This is an automated instruction, just in case, because many review tags
are being ignored. If you know the process, you can skip it (please do
not feel offended by me posting it here - no bad intentions intended).
If you do not know the process, here is a short explanation:

Please add Acked-by/Reviewed-by/Tested-by tags when posting new
versions of patchset, under or above your Signed-off-by tag, unless
patch changed significantly (e.g. new properties added to the DT
bindings). Tag is "received", when provided in a message replied to you
on the mailing list. Tools like b4 can help here. However, there's no
need to repost patches *only* to add the tags. The upstream maintainer
will do that for tags received on the version they apply.

https://elixir.bootlin.com/linux/v6.12-rc3/source/Documentation/process/submitting-patches.rst#L577
</form letter>

Best regards,
Krzysztof

[PATCH v2 0/2] Add driver for HTU31

[Andrei Lalaev]

This patch series adds support for HTU31 humidity and temperature
sensor.

Changes in v2:
- replace DIV_ROUND_CLOSEST with DIV_ROUND_CLOSEST_ULL to prevent
  possible overflow
- drop mutex locking from htu31_read_serial_number, as the function is
  only called from probe
- add description of the private data structure
- fix the issues pointed by Christophe
- add an entry to MAINTAINERS file
- add Krzysztof's ACK to dt-bindings patch

v1: https://lore.kernel.org/all/20250123202528.223966-1-andrey.lalaev@gmail.com/#t

Andrei Lalaev (2):
  hwmon: add driver for HTU31
  dt-bindings: hwmon: Add description for sensor HTU31

 .../devicetree/bindings/trivial-devices.yaml  |   2 +
 Documentation/hwmon/htu31.rst                 |  38 ++
 Documentation/hwmon/index.rst                 |   1 +
 MAINTAINERS                                   |   6 +
 drivers/hwmon/Kconfig                         |  11 +
 drivers/hwmon/Makefile                        |   1 +
 drivers/hwmon/htu31.c                         | 345 ++++++++++++++++++
 7 files changed, 404 insertions(+)
 create mode 100644 Documentation/hwmon/htu31.rst
 create mode 100644 drivers/hwmon/htu31.c

-- 
2.48.1

[PATCH 2/2] dt-bindings: hwmon: Add description for sensor HTU31

[Andrei Lalaev]

Add trivial binding for HTU31 Temperature and Humidity sensor.

Signed-off-by: Andrei Lalaev <andrey.lalaev@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/trivial-devices.yaml b/Documentation/devicetree/bindings/trivial-devices.yaml
index 6bdcd055e763..294e8f9bfb4a 100644
--- a/Documentation/devicetree/bindings/trivial-devices.yaml
+++ b/Documentation/devicetree/bindings/trivial-devices.yaml
@@ -189,6 +189,8 @@ properties:
           - mcube,mc3230
             # Measurement Specialities I2C temperature and humidity sensor
           - meas,htu21
+            # Measurement Specialities I2C temperature and humidity sensor
+          - meas,htu31
             # Measurement Specialities I2C pressure and temperature sensor
           - meas,ms5637
             # Measurement Specialities I2C pressure and temperature sensor
-- 
2.48.1

Re: [PATCH 2/2] dt-bindings: hwmon: Add description for sensor HTU31

[Krzysztof Kozlowski]

On Sun, Jan 26, 2025 at 03:40:56PM +0100, Andrei Lalaev wrote:
> Add trivial binding for HTU31 Temperature and Humidity sensor.
> 
> Signed-off-by: Andrei Lalaev <andrey.lalaev@gmail.com>
> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> ---
>  Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 

Please version your patchsets correctly. `git format-patch -v2` or b4.

This is not v1 and you could not get my ack on v1.

Best regards,
Krzysztof

Re: [PATCH 2/2] dt-bindings: hwmon: Add description for sensor HTU31

[Andrei Lalaev]

On 27.01.2025 08:07, Krzysztof Kozlowski wrote:
> On Sun, Jan 26, 2025 at 03:40:56PM +0100, Andrei Lalaev wrote:
>> Add trivial binding for HTU31 Temperature and Humidity sensor.
>>
>> Signed-off-by: Andrei Lalaev <andrey.lalaev@gmail.com>
>> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>> ---
>>  Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
>>  1 file changed, 2 insertions(+)
>>
> 
> Please version your patchsets correctly. `git format-patch -v2` or b4.
> 
> This is not v1 and you could not get my ack on v1.
> 

Oh, my bad, sorry, I manually edited the cover letter and forgot about patches' subjects :/

Should I resend v2 with normal versioning, or would you prefer me to go straight to v3?

Best regards,
Andrei Lalaev

Re: [PATCH 2/2] dt-bindings: hwmon: Add description for sensor HTU31

[Krzysztof Kozlowski]

On 27/01/2025 20:21, Andrei Lalaev wrote:
> On 27.01.2025 08:07, Krzysztof Kozlowski wrote:
>> On Sun, Jan 26, 2025 at 03:40:56PM +0100, Andrei Lalaev wrote:
>>> Add trivial binding for HTU31 Temperature and Humidity sensor.
>>>
>>> Signed-off-by: Andrei Lalaev <andrey.lalaev@gmail.com>
>>> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>>> ---
>>>  Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
>>>  1 file changed, 2 insertions(+)
>>>
>>
>> Please version your patchsets correctly. `git format-patch -v2` or b4.
>>
>> This is not v1 and you could not get my ack on v1.
>>
> 
> Oh, my bad, sorry, I manually edited the cover letter and forgot about patches' subjects :/
> 
> Should I resend v2 with normal versioning, or would you prefer me to go straight to v3?

Tools might work fine with it, so no need to resend, unless Guenter
asks. But if you send v3 for any reason, be sure to mark all of the patches.

Best regards,
Krzysztof

Re: [PATCH 2/2] dt-bindings: hwmon: Add description for sensor HTU31

[Guenter Roeck]

On 1/27/25 11:39, Krzysztof Kozlowski wrote:
> On 27/01/2025 20:21, Andrei Lalaev wrote:
>> On 27.01.2025 08:07, Krzysztof Kozlowski wrote:
>>> On Sun, Jan 26, 2025 at 03:40:56PM +0100, Andrei Lalaev wrote:
>>>> Add trivial binding for HTU31 Temperature and Humidity sensor.
>>>>
>>>> Signed-off-by: Andrei Lalaev <andrey.lalaev@gmail.com>
>>>> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>>>> ---
>>>>   Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
>>>>   1 file changed, 2 insertions(+)
>>>>
>>>
>>> Please version your patchsets correctly. `git format-patch -v2` or b4.
>>>
>>> This is not v1 and you could not get my ack on v1.
>>>
>>
>> Oh, my bad, sorry, I manually edited the cover letter and forgot about patches' subjects :/
>>
>> Should I resend v2 with normal versioning, or would you prefer me to go straight to v3?
> 
> Tools might work fine with it, so no need to resend, unless Guenter
> asks. But if you send v3 for any reason, be sure to mark all of the patches.
> 

Please no resend just to add version numbers to the patches.

Guenter