iio: chemical: add AMS iAQ-core support (466df4d0) · Commits · e / devices / android_kernel_fairphone_FP3

Documentation/devicetree/bindings/i2c/trivial-devices.txt

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		@@ -20,6 +20,7 @@ adi,adt7476 +/-1C TDM Extended Temp Range I.C
		adi,adt7490 +/-1C TDM Extended Temp Range I.C
		adi,adxl345 Three-Axis Digital Accelerometer
		adi,adxl346 Three-Axis Digital Accelerometer (backward-compatibility value "adi,adxl345" must be listed too)
		ams,iaq-core AMS iAQ-Core VOC Sensor
		at,24c08 i2c serial eeprom (24cxx)
		atmel,24c00 i2c serial eeprom (24cxx)
		atmel,24c01 i2c serial eeprom (24cxx)

drivers/iio/chemical/Kconfig

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		@@ -4,6 +4,14 @@

		menu "Chemical Sensors"

		config IAQCORE
		tristate "AMS iAQ-Core VOC sensors"
		depends on I2C
		help
		Say Y here to build I2C interface support for the AMS
		iAQ-Core Continuous/Pulsed VOC (Volatile Organic Compounds)
		sensors

		config VZ89X
		tristate "SGX Sensortech MiCS VZ89X VOC sensor"
		depends on I2C

drivers/iio/chemical/Makefile

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		@@ -3,4 +3,5 @@
		#

		# When adding new entries keep the list in alphabetical order
		obj-$(CONFIG_IAQCORE) += ams-iaq-core.o
		obj-$(CONFIG_VZ89X) += vz89x.o

drivers/iio/chemical/ams-iaq-core.c

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		/*
		* ams-iaq-core.c - Support for AMS iAQ-Core VOC sensors
		*
		* Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com>
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2 of the License, or
		* (at your option) any later version.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		*/

		#include <linux/module.h>
		#include <linux/mutex.h>
		#include <linux/init.h>
		#include <linux/i2c.h>
		#include <linux/iio/iio.h>

		#define AMS_IAQCORE_DATA_SIZE 9

		#define AMS_IAQCORE_VOC_CO2_IDX 0
		#define AMS_IAQCORE_VOC_RESISTANCE_IDX 1
		#define AMS_IAQCORE_VOC_TVOC_IDX 2

		struct ams_iaqcore_reading {
		__be16 co2_ppm;
		u8 status;
		__be32 resistance;
		__be16 voc_ppb;
		} __attribute__((__packed__));

		struct ams_iaqcore_data {
		struct i2c_client *client;
		struct mutex lock;
		unsigned long last_update;

		struct ams_iaqcore_reading buffer;
		};

		static const struct iio_chan_spec ams_iaqcore_channels[] = {
		{
		.type = IIO_CONCENTRATION,
		.channel2 = IIO_MOD_CO2,
		.modified = 1,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
		.address = AMS_IAQCORE_VOC_CO2_IDX,
		},
		{
		.type = IIO_RESISTANCE,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
		.address = AMS_IAQCORE_VOC_RESISTANCE_IDX,
		},
		{
		.type = IIO_CONCENTRATION,
		.channel2 = IIO_MOD_VOC,
		.modified = 1,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
		.address = AMS_IAQCORE_VOC_TVOC_IDX,
		},
		};

		static int ams_iaqcore_read_measurement(struct ams_iaqcore_data *data)
		{
		struct i2c_client *client = data->client;
		int ret;

		struct i2c_msg msg = {
		.addr = client->addr,
		.flags = client->flags \| I2C_M_RD,
		.len = AMS_IAQCORE_DATA_SIZE,
		.buf = (char *) &data->buffer,
		};

		ret = i2c_transfer(client->adapter, &msg, 1);

		return (ret == AMS_IAQCORE_DATA_SIZE) ? 0 : ret;
		}

		static int ams_iaqcore_get_measurement(struct ams_iaqcore_data *data)
		{
		int ret;

		/* sensor can only be polled once a second max per datasheet */
		if (!time_after(jiffies, data->last_update + HZ))
		return 0;

		ret = ams_iaqcore_read_measurement(data);
		if (ret < 0)
		return ret;

		data->last_update = jiffies;

		return 0;
		}

		static int ams_iaqcore_read_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const chan, int val,
		int *val2, long mask)
		{
		struct ams_iaqcore_data *data = iio_priv(indio_dev);
		int ret;

		if (mask != IIO_CHAN_INFO_PROCESSED)
		return -EINVAL;

		mutex_lock(&data->lock);
		ret = ams_iaqcore_get_measurement(data);

		if (ret)
		goto err_out;

		switch (chan->address) {
		case AMS_IAQCORE_VOC_CO2_IDX:
		*val = 0;
		*val2 = be16_to_cpu(data->buffer.co2_ppm);
		ret = IIO_VAL_INT_PLUS_MICRO;
		break;
		case AMS_IAQCORE_VOC_RESISTANCE_IDX:
		*val = be32_to_cpu(data->buffer.resistance);
		ret = IIO_VAL_INT;
		break;
		case AMS_IAQCORE_VOC_TVOC_IDX:
		*val = 0;
		*val2 = be16_to_cpu(data->buffer.voc_ppb);
		ret = IIO_VAL_INT_PLUS_NANO;
		break;
		default:
		ret = -EINVAL;
		}

		err_out:
		mutex_unlock(&data->lock);

		return ret;
		}

		static const struct iio_info ams_iaqcore_info = {
		.read_raw = ams_iaqcore_read_raw,
		.driver_module = THIS_MODULE,
		};

		static int ams_iaqcore_probe(struct i2c_client *client,
		const struct i2c_device_id *id)
		{
		struct iio_dev *indio_dev;
		struct ams_iaqcore_data *data;

		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);
		data->client = client;

		/* so initial reading will complete */
		data->last_update = jiffies - HZ;
		mutex_init(&data->lock);

		indio_dev->dev.parent = &client->dev;
		indio_dev->info = &ams_iaqcore_info,
		indio_dev->name = dev_name(&client->dev);
		indio_dev->modes = INDIO_DIRECT_MODE;

		indio_dev->channels = ams_iaqcore_channels;
		indio_dev->num_channels = ARRAY_SIZE(ams_iaqcore_channels);

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

		static const struct i2c_device_id ams_iaqcore_id[] = {
		{ "ams-iaq-core", 0 },
		{ }
		};
		MODULE_DEVICE_TABLE(i2c, ams_iaqcore_id);

		static const struct of_device_id ams_iaqcore_dt_ids[] = {
		{ .compatible = "ams,iaq-core" },
		{ }
		};
		MODULE_DEVICE_TABLE(of, ams_iaqcore_dt_ids);

		static struct i2c_driver ams_iaqcore_driver = {
		.driver = {
		.name = "ams-iaq-core",
		.of_match_table = of_match_ptr(ams_iaqcore_dt_ids),
		},
		.probe = ams_iaqcore_probe,
		.id_table = ams_iaqcore_id,
		};
		module_i2c_driver(ams_iaqcore_driver);

		MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
		MODULE_DESCRIPTION("AMS iAQ-Core VOC sensors");
		MODULE_LICENSE("GPL v2");