iio: chemical: Add driver for SEN0322 (d524b3e0) · Commits · git / linux-nf

MAINTAINERS

+6 −0

Original line number	Diff line number	Diff line
		@@ -6863,6 +6863,12 @@ L: linux-rtc@vger.kernel.org
		S: Maintained
		F: drivers/rtc/rtc-sd2405al.c

		DFROBOT SEN0322 DRIVER
		M: Tóth János <gomba007@gmail.com>
		L: linux-iio@vger.kernel.org
		S: Maintained
		F: drivers/iio/chemical/sen0322.c

		DH ELECTRONICS DHSOM SOM AND BOARD SUPPORT
		M: Christoph Niedermaier <cniedermaier@dh-electronics.com>
		M: Marek Vasut <marex@denx.de>

drivers/iio/chemical/Kconfig

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		@@ -176,6 +176,16 @@ config SCD4X
		To compile this driver as a module, choose M here: the module will
		be called scd4x.

		config SEN0322
		tristate "SEN0322 oxygen sensor"
		depends on I2C
		select REGMAP_I2C
		help
		Say Y here to build support for the DFRobot SEN0322 oxygen sensor.

		To compile this driver as a module, choose M here: the module will
		be called sen0322.

		config SENSIRION_SGP30
		tristate "Sensirion SGPxx gas sensors"
		depends on I2C

drivers/iio/chemical/Makefile

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		@@ -21,6 +21,7 @@ obj-$(CONFIG_SCD30_CORE) += scd30_core.o
		obj-$(CONFIG_SCD30_I2C) += scd30_i2c.o
		obj-$(CONFIG_SCD30_SERIAL) += scd30_serial.o
		obj-$(CONFIG_SCD4X) += scd4x.o
		obj-$(CONFIG_SEN0322) += sen0322.o
		obj-$(CONFIG_SENSEAIR_SUNRISE_CO2) += sunrise_co2.o
		obj-$(CONFIG_SENSIRION_SGP30) += sgp30.o
		obj-$(CONFIG_SENSIRION_SGP40) += sgp40.o

drivers/iio/chemical/sen0322.c

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		// SPDX-License-Identifier: GPL-2.0
		/*
		* Driver for the DFRobot SEN0322 oxygen sensor.
		*
		* Datasheet:
		* https://wiki.dfrobot.com/Gravity_I2C_Oxygen_Sensor_SKU_SEN0322
		*
		* Possible I2C slave addresses:
		* 0x70
		* 0x71
		* 0x72
		* 0x73
		*
		* Copyright (C) 2025 Tóth János <gomba007@gmail.com>
		*/

		#include <linux/i2c.h>
		#include <linux/regmap.h>

		#include <linux/iio/iio.h>

		#define SEN0322_REG_DATA 0x03
		#define SEN0322_REG_COEFF 0x0A

		struct sen0322 {
		struct regmap *regmap;
		};

		static int sen0322_read_data(struct sen0322 *sen0322)
		{
		u8 data[3] = { };
		int ret;

		ret = regmap_bulk_read(sen0322->regmap, SEN0322_REG_DATA, data,
		sizeof(data));
		if (ret < 0)
		return ret;

		/*
		* The actual value in the registers is:
		* val = data[0] + data[1] / 10 + data[2] / 100
		* but it is multiplied by 100 here to avoid floating-point math
		* and the scale is divided by 100 to compensate this.
		*/
		return data[0] * 100 + data[1] * 10 + data[2];
		}

		static int sen0322_read_scale(struct sen0322 sen0322, int num, int *den)
		{
		u32 val;
		int ret;

		ret = regmap_read(sen0322->regmap, SEN0322_REG_COEFF, &val);
		if (ret < 0)
		return ret;

		if (val) {
		*num = val;
		den = 100000; / Coeff is scaled by 1000 at calibration. */
		} else { /* The device is not calibrated, using the factory-defaults. */
		num = 209; / Oxygen content in the atmosphere is 20.9%. */
		den = 120000; / Output of the sensor at 20.9% is 120 uA. */
		}

		dev_dbg(regmap_get_device(sen0322->regmap), "scale: %d/%d\n",
		num, den);

		return 0;
		}

		static int sen0322_read_raw(struct iio_dev *iio_dev,
		const struct iio_chan_spec *chan,
		int val, int val2, long mask)
		{
		struct sen0322 *sen0322 = iio_priv(iio_dev);
		int ret;

		if (chan->type != IIO_CONCENTRATION)
		return -EINVAL;

		switch (mask) {
		case IIO_CHAN_INFO_RAW:
		ret = sen0322_read_data(sen0322);
		if (ret < 0)
		return ret;

		*val = ret;
		return IIO_VAL_INT;

		case IIO_CHAN_INFO_SCALE:
		ret = sen0322_read_scale(sen0322, val, val2);
		if (ret < 0)
		return ret;

		return IIO_VAL_FRACTIONAL;

		default:
		return -EINVAL;
		}
		}

		static const struct iio_info sen0322_info = {
		.read_raw = sen0322_read_raw,
		};

		static const struct regmap_config sen0322_regmap_conf = {
		.reg_bits = 8,
		.val_bits = 8,
		};

		static const struct iio_chan_spec sen0322_channel = {
		.type = IIO_CONCENTRATION,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \|
		BIT(IIO_CHAN_INFO_SCALE),
		};

		static int sen0322_probe(struct i2c_client *client)
		{
		struct sen0322 *sen0322;
		struct iio_dev *iio_dev;

		if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
		return -ENODEV;

		iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*sen0322));
		if (!iio_dev)
		return -ENOMEM;

		sen0322 = iio_priv(iio_dev);

		sen0322->regmap = devm_regmap_init_i2c(client, &sen0322_regmap_conf);
		if (IS_ERR(sen0322->regmap))
		return PTR_ERR(sen0322->regmap);

		iio_dev->info = &sen0322_info;
		iio_dev->name = "sen0322";
		iio_dev->channels = &sen0322_channel;
		iio_dev->num_channels = 1;
		iio_dev->modes = INDIO_DIRECT_MODE;

		return devm_iio_device_register(&client->dev, iio_dev);
		}

		static const struct of_device_id sen0322_of_match[] = {
		{ .compatible = "dfrobot,sen0322" },
		{ }
		};
		MODULE_DEVICE_TABLE(of, sen0322_of_match);

		static struct i2c_driver sen0322_driver = {
		.driver = {
		.name = "sen0322",
		.of_match_table = sen0322_of_match,
		},
		.probe = sen0322_probe,
		};
		module_i2c_driver(sen0322_driver);

		MODULE_AUTHOR("Tóth János <gomba007@gmail.com>");
		MODULE_LICENSE("GPL");
		MODULE_DESCRIPTION("SEN0322 oxygen sensor driver");