[linux-2.6-block.git] / drivers / iio / chemical / ccs811.c

/*
 * ccs811.c - Support for AMS CCS811 VOC Sensor
 *
 * Copyright (C) 2017 Narcisa Vasile <narcisaanamaria12@gmail.com>
 *
 * Datasheet: ams.com/content/download/951091/2269479/CCS811_DS000459_3-00.pdf
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * IIO driver for AMS CCS811 (I2C address 0x5A/0x5B set by ADDR Low/High)
 *
 * TODO:
 * 1. Make the drive mode selectable form userspace
 * 2. Add support for interrupts
 * 3. Adjust time to wait for data to be ready based on selected operation mode
 * 4. Read error register and put the information in logs
 */

#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/module.h>

#define CCS811_STATUS		0x00
#define CCS811_MEAS_MODE	0x01
#define CCS811_ALG_RESULT_DATA	0x02
#define CCS811_RAW_DATA		0x03
#define CCS811_HW_ID		0x20
#define CCS881_HW_ID_VALUE	0x81
#define CCS811_HW_VERSION	0x21
#define CCS811_HW_VERSION_VALUE	0x10
#define CCS811_HW_VERSION_MASK	0xF0
#define CCS811_ERR		0xE0
/* Used to transition from boot to application mode */
#define CCS811_APP_START	0xF4

/* Status register flags */
#define CCS811_STATUS_ERROR		BIT(0)
#define CCS811_STATUS_DATA_READY	BIT(3)
#define CCS811_STATUS_APP_VALID_MASK	BIT(4)
#define CCS811_STATUS_APP_VALID_LOADED	BIT(4)
/*
 * Value of FW_MODE bit of STATUS register describes the sensor's state:
 * 0: Firmware is in boot mode, this allows new firmware to be loaded
 * 1: Firmware is in application mode. CCS811 is ready to take ADC measurements
 */
#define CCS811_STATUS_FW_MODE_MASK	BIT(7)
#define CCS811_STATUS_FW_MODE_APPLICATION	BIT(7)

/* Measurement modes */
#define CCS811_MODE_IDLE	0x00
#define CCS811_MODE_IAQ_1SEC	0x10
#define CCS811_MODE_IAQ_10SEC	0x20
#define CCS811_MODE_IAQ_60SEC	0x30
#define CCS811_MODE_RAW_DATA	0x40

#define CCS811_MEAS_MODE_INTERRUPT	BIT(3)

#define CCS811_VOLTAGE_MASK	0x3FF

struct ccs811_reading {
	__be16 co2;
	__be16 voc;
	u8 status;
	u8 error;
	__be16 resistance;
} __attribute__((__packed__));

struct ccs811_data {
	struct i2c_client *client;
	struct mutex lock; /* Protect readings */
	struct ccs811_reading buffer;
	struct iio_trigger *drdy_trig;
	bool drdy_trig_on;
};

static const struct iio_chan_spec ccs811_channels[] = {
	{
		.type = IIO_CURRENT,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
				      BIT(IIO_CHAN_INFO_SCALE),
		.scan_index = -1,
	}, {
		.type = IIO_VOLTAGE,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
				      BIT(IIO_CHAN_INFO_SCALE),
		.scan_index = -1,
	}, {
		.type = IIO_CONCENTRATION,
		.channel2 = IIO_MOD_CO2,
		.modified = 1,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
				      BIT(IIO_CHAN_INFO_SCALE),
		.scan_index = 0,
		.scan_type = {
			.sign = 'u',
			.realbits = 16,
			.storagebits = 16,
			.endianness = IIO_BE,
		},
	}, {
		.type = IIO_CONCENTRATION,
		.channel2 = IIO_MOD_VOC,
		.modified = 1,
		.info_mask_separate =  BIT(IIO_CHAN_INFO_RAW) |
				       BIT(IIO_CHAN_INFO_SCALE),
		.scan_index = 1,
		.scan_type = {
			.sign = 'u',
			.realbits = 16,
			.storagebits = 16,
			.endianness = IIO_BE,
		},
	},
	IIO_CHAN_SOFT_TIMESTAMP(2),
};

/*
 * The CCS811 powers-up in boot mode. A setup write to CCS811_APP_START will
 * transition the sensor to application mode.
 */
static int ccs811_start_sensor_application(struct i2c_client *client)
{
	int ret;

	ret = i2c_smbus_read_byte_data(client, CCS811_STATUS);
	if (ret < 0)
		return ret;

	if ((ret & CCS811_STATUS_FW_MODE_APPLICATION))
		return 0;

	if ((ret & CCS811_STATUS_APP_VALID_MASK) !=
	    CCS811_STATUS_APP_VALID_LOADED)
		return -EIO;

	ret = i2c_smbus_write_byte(client, CCS811_APP_START);
	if (ret < 0)
		return ret;

	ret = i2c_smbus_read_byte_data(client, CCS811_STATUS);
	if (ret < 0)
		return ret;

	if ((ret & CCS811_STATUS_FW_MODE_MASK) !=
	    CCS811_STATUS_FW_MODE_APPLICATION) {
		dev_err(&client->dev, "Application failed to start. Sensor is still in boot mode.\n");
		return -EIO;
	}

	return 0;
}

static int ccs811_setup(struct i2c_client *client)
{
	int ret;

	ret = ccs811_start_sensor_application(client);
	if (ret < 0)
		return ret;

	return i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE,
					 CCS811_MODE_IAQ_1SEC);
}

static int ccs811_get_measurement(struct ccs811_data *data)
{
	int ret, tries = 11;

	/* Maximum waiting time: 1s, as measurements are made every second */
	while (tries-- > 0) {
		ret = i2c_smbus_read_byte_data(data->client, CCS811_STATUS);
		if (ret < 0)
			return ret;

		if ((ret & CCS811_STATUS_DATA_READY) || tries == 0)
			break;
		msleep(100);
	}
	if (!(ret & CCS811_STATUS_DATA_READY))
		return -EIO;

	return i2c_smbus_read_i2c_block_data(data->client,
					    CCS811_ALG_RESULT_DATA, 8,
					    (char *)&data->buffer);
}

static int ccs811_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int *val, int *val2, long mask)
{
	struct ccs811_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = iio_device_claim_direct_mode(indio_dev);
		if (ret)
			return ret;
		mutex_lock(&data->lock);
		ret = ccs811_get_measurement(data);
		if (ret < 0) {
			mutex_unlock(&data->lock);
			iio_device_release_direct_mode(indio_dev);
			return ret;
		}

		switch (chan->type) {
		case IIO_VOLTAGE:
			*val = be16_to_cpu(data->buffer.resistance) &
					   CCS811_VOLTAGE_MASK;
			ret = IIO_VAL_INT;
			break;
		case IIO_CURRENT:
			*val = be16_to_cpu(data->buffer.resistance) >> 10;
			ret = IIO_VAL_INT;
			break;
		case IIO_CONCENTRATION:
			switch (chan->channel2) {
			case IIO_MOD_CO2:
				*val = be16_to_cpu(data->buffer.co2);
				ret =  IIO_VAL_INT;
				break;
			case IIO_MOD_VOC:
				*val = be16_to_cpu(data->buffer.voc);
				ret = IIO_VAL_INT;
				break;
			default:
				ret = -EINVAL;
			}
			break;
		default:
			ret = -EINVAL;
		}
		mutex_unlock(&data->lock);
		iio_device_release_direct_mode(indio_dev);

		return ret;

	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_VOLTAGE:
			*val = 1;
			*val2 = 612903;
			return IIO_VAL_INT_PLUS_MICRO;
		case IIO_CURRENT:
			*val = 0;
			*val2 = 1000;
			return IIO_VAL_INT_PLUS_MICRO;
		case IIO_CONCENTRATION:
			switch (chan->channel2) {
			case IIO_MOD_CO2:
				*val = 0;
				*val2 = 100;
				return IIO_VAL_INT_PLUS_MICRO;
			case IIO_MOD_VOC:
				*val = 0;
				*val2 = 100;
				return IIO_VAL_INT_PLUS_NANO;
			default:
				return -EINVAL;
			}
		default:
			return -EINVAL;
		}
	default:
		return -EINVAL;
	}
}

static const struct iio_info ccs811_info = {
	.read_raw = ccs811_read_raw,
};

static int ccs811_set_trigger_state(struct iio_trigger *trig,
				    bool state)
{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	struct ccs811_data *data = iio_priv(indio_dev);
	int ret;

	ret = i2c_smbus_read_byte_data(data->client, CCS811_MEAS_MODE);
	if (ret < 0)
		return ret;

	if (state)
		ret |= CCS811_MEAS_MODE_INTERRUPT;
	else
		ret &= ~CCS811_MEAS_MODE_INTERRUPT;

	data->drdy_trig_on = state;

	return i2c_smbus_write_byte_data(data->client, CCS811_MEAS_MODE, ret);
}

static const struct iio_trigger_ops ccs811_trigger_ops = {
	.set_trigger_state = ccs811_set_trigger_state,
};

static irqreturn_t ccs811_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct ccs811_data *data = iio_priv(indio_dev);
	struct i2c_client *client = data->client;
	s16 buf[8]; /* s16 eCO2 + s16 TVOC + padding + 8 byte timestamp */
	int ret;

	ret = i2c_smbus_read_i2c_block_data(client, CCS811_ALG_RESULT_DATA, 4,
					    (u8 *)&buf);
	if (ret != 4) {
		dev_err(&client->dev, "cannot read sensor data\n");
		goto err;
	}

	iio_push_to_buffers_with_timestamp(indio_dev, buf,
					   iio_get_time_ns(indio_dev));

err:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

static irqreturn_t ccs811_data_rdy_trigger_poll(int irq, void *private)
{
	struct iio_dev *indio_dev = private;
	struct ccs811_data *data = iio_priv(indio_dev);

	if (data->drdy_trig_on)
		iio_trigger_poll(data->drdy_trig);

	return IRQ_HANDLED;
}

static int ccs811_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct iio_dev *indio_dev;
	struct ccs811_data *data;
	int ret;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE
				     | I2C_FUNC_SMBUS_BYTE_DATA
				     | I2C_FUNC_SMBUS_READ_I2C_BLOCK))
		return -EOPNOTSUPP;

	/* Check hardware id (should be 0x81 for this family of devices) */
	ret = i2c_smbus_read_byte_data(client, CCS811_HW_ID);
	if (ret < 0)
		return ret;

	if (ret != CCS881_HW_ID_VALUE) {
		dev_err(&client->dev, "hardware id doesn't match CCS81x\n");
		return -ENODEV;
	}

	ret = i2c_smbus_read_byte_data(client, CCS811_HW_VERSION);
	if (ret < 0)
		return ret;

	if ((ret & CCS811_HW_VERSION_MASK) != CCS811_HW_VERSION_VALUE) {
		dev_err(&client->dev, "no CCS811 sensor\n");
		return -ENODEV;
	}

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

	ret = ccs811_setup(client);
	if (ret < 0)
		return ret;

	data = iio_priv(indio_dev);
	i2c_set_clientdata(client, indio_dev);
	data->client = client;

	mutex_init(&data->lock);

	indio_dev->dev.parent = &client->dev;
	indio_dev->name = id->name;
	indio_dev->info = &ccs811_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->channels = ccs811_channels;
	indio_dev->num_channels = ARRAY_SIZE(ccs811_channels);

	if (client->irq > 0) {
		ret = devm_request_threaded_irq(&client->dev, client->irq,
						ccs811_data_rdy_trigger_poll,
						NULL,
						IRQF_TRIGGER_FALLING |
						IRQF_ONESHOT,
						"ccs811_irq", indio_dev);
		if (ret) {
			dev_err(&client->dev, "irq request error %d\n", -ret);
			goto err_poweroff;
		}

		data->drdy_trig = devm_iio_trigger_alloc(&client->dev,
							 "%s-dev%d",
							 indio_dev->name,
							 indio_dev->id);
		if (!data->drdy_trig) {
			ret = -ENOMEM;
			goto err_poweroff;
		}

		data->drdy_trig->dev.parent = &client->dev;
		data->drdy_trig->ops = &ccs811_trigger_ops;
		iio_trigger_set_drvdata(data->drdy_trig, indio_dev);
		indio_dev->trig = data->drdy_trig;
		iio_trigger_get(indio_dev->trig);
		ret = iio_trigger_register(data->drdy_trig);
		if (ret)
			goto err_poweroff;
	}

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
					 ccs811_trigger_handler, NULL);

	if (ret < 0) {
		dev_err(&client->dev, "triggered buffer setup failed\n");
		goto err_trigger_unregister;
	}

	ret = iio_device_register(indio_dev);
	if (ret < 0) {
		dev_err(&client->dev, "unable to register iio device\n");
		goto err_buffer_cleanup;
	}
	return 0;

err_buffer_cleanup:
	iio_triggered_buffer_cleanup(indio_dev);
err_trigger_unregister:
	if (data->drdy_trig)
		iio_trigger_unregister(data->drdy_trig);
err_poweroff:
	i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE, CCS811_MODE_IDLE);

	return ret;
}

static int ccs811_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct ccs811_data *data = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);
	if (data->drdy_trig)
		iio_trigger_unregister(data->drdy_trig);

	return i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE,
					 CCS811_MODE_IDLE);
}

static const struct i2c_device_id ccs811_id[] = {
	{"ccs811", 0},
	{	}
};
MODULE_DEVICE_TABLE(i2c, ccs811_id);

static struct i2c_driver ccs811_driver = {
	.driver = {
		.name = "ccs811",
	},
	.probe = ccs811_probe,
	.remove = ccs811_remove,
	.id_table = ccs811_id,
};
module_i2c_driver(ccs811_driver);

MODULE_AUTHOR("Narcisa Vasile <narcisaanamaria12@gmail.com>");
MODULE_DESCRIPTION("CCS811 volatile organic compounds sensor");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
a94c24a7 NAMV	1	/*
	2	* ccs811.c - Support for AMS CCS811 VOC Sensor
	3	*
	4	* Copyright (C) 2017 Narcisa Vasile <narcisaanamaria12@gmail.com>
	5	*
	6	* Datasheet: ams.com/content/download/951091/2269479/CCS811_DS000459_3-00.pdf
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
	12	* IIO driver for AMS CCS811 (I2C address 0x5A/0x5B set by ADDR Low/High)
	13	*
	14	* TODO:
	15	* 1. Make the drive mode selectable form userspace
	16	* 2. Add support for interrupts
	17	* 3. Adjust time to wait for data to be ready based on selected operation mode
	18	* 4. Read error register and put the information in logs
	19	*/
	20
	21	#include <linux/delay.h>
	22	#include <linux/i2c.h>
	23	#include <linux/iio/iio.h>
283d2691	24	#include <linux/iio/buffer.h>
f1f065d7	25	#include <linux/iio/trigger.h>
283d2691 NAMV	26	#include <linux/iio/triggered_buffer.h>
283d2691 NAMV	27	#include <linux/iio/trigger_consumer.h>
a94c24a7 NAMV	28	#include <linux/module.h>
	29
	30	#define CCS811_STATUS 0x00
	31	#define CCS811_MEAS_MODE 0x01
	32	#define CCS811_ALG_RESULT_DATA 0x02
	33	#define CCS811_RAW_DATA 0x03
	34	#define CCS811_HW_ID 0x20
	35	#define CCS881_HW_ID_VALUE 0x81
	36	#define CCS811_HW_VERSION 0x21
	37	#define CCS811_HW_VERSION_VALUE 0x10
	38	#define CCS811_HW_VERSION_MASK 0xF0
	39	#define CCS811_ERR 0xE0
	40	/* Used to transition from boot to application mode */
	41	#define CCS811_APP_START 0xF4
	42
	43	/* Status register flags */
	44	#define CCS811_STATUS_ERROR BIT(0)
	45	#define CCS811_STATUS_DATA_READY BIT(3)
	46	#define CCS811_STATUS_APP_VALID_MASK BIT(4)
	47	#define CCS811_STATUS_APP_VALID_LOADED BIT(4)
	48	/*
	49	* Value of FW_MODE bit of STATUS register describes the sensor's state:
	50	* 0: Firmware is in boot mode, this allows new firmware to be loaded
	51	* 1: Firmware is in application mode. CCS811 is ready to take ADC measurements
	52	*/
	53	#define CCS811_STATUS_FW_MODE_MASK BIT(7)
	54	#define CCS811_STATUS_FW_MODE_APPLICATION BIT(7)
	55
	56	/* Measurement modes */
	57	#define CCS811_MODE_IDLE 0x00
	58	#define CCS811_MODE_IAQ_1SEC 0x10
	59	#define CCS811_MODE_IAQ_10SEC 0x20
	60	#define CCS811_MODE_IAQ_60SEC 0x30
	61	#define CCS811_MODE_RAW_DATA 0x40
	62
f1f065d7 NAMV	63	#define CCS811_MEAS_MODE_INTERRUPT BIT(3)
f1f065d7 NAMV	64
a94c24a7 NAMV	65	#define CCS811_VOLTAGE_MASK 0x3FF
	66
	67	struct ccs811_reading {
	68	__be16 co2;
	69	__be16 voc;
	70	u8 status;
	71	u8 error;
	72	__be16 resistance;
	73	} __attribute__((__packed__));
	74
	75	struct ccs811_data {
	76	struct i2c_client *client;
	77	struct mutex lock; /* Protect readings */
	78	struct ccs811_reading buffer;
f1f065d7 NAMV	79	struct iio_trigger *drdy_trig;
f1f065d7 NAMV	80	bool drdy_trig_on;
a94c24a7 NAMV	81	};
	82
	83	static const struct iio_chan_spec ccs811_channels[] = {
	84	{
	85	.type = IIO_CURRENT,
	86	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \|
283d2691 NAMV	87	BIT(IIO_CHAN_INFO_SCALE),
283d2691 NAMV	88	.scan_index = -1,
a94c24a7 NAMV	89	}, {
	90	.type = IIO_VOLTAGE,
	91	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \|
283d2691 NAMV	92	BIT(IIO_CHAN_INFO_SCALE),
283d2691 NAMV	93	.scan_index = -1,
a94c24a7 NAMV	94	}, {
	95	.type = IIO_CONCENTRATION,
	96	.channel2 = IIO_MOD_CO2,
	97	.modified = 1,
	98	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \|
283d2691 NAMV	99	BIT(IIO_CHAN_INFO_SCALE),
	100	.scan_index = 0,
	101	.scan_type = {
	102	.sign = 'u',
	103	.realbits = 16,
	104	.storagebits = 16,
	105	.endianness = IIO_BE,
	106	},
a94c24a7 NAMV	107	}, {
	108	.type = IIO_CONCENTRATION,
	109	.channel2 = IIO_MOD_VOC,
	110	.modified = 1,
	111	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \|
283d2691 NAMV	112	BIT(IIO_CHAN_INFO_SCALE),
	113	.scan_index = 1,
	114	.scan_type = {
	115	.sign = 'u',
	116	.realbits = 16,
	117	.storagebits = 16,
	118	.endianness = IIO_BE,
	119	},
a94c24a7	120	},
283d2691	121	IIO_CHAN_SOFT_TIMESTAMP(2),
a94c24a7 NAMV	122	};
	123
	124	/*
	125	* The CCS811 powers-up in boot mode. A setup write to CCS811_APP_START will
	126	* transition the sensor to application mode.
	127	*/
	128	static int ccs811_start_sensor_application(struct i2c_client *client)
	129	{
	130	int ret;
	131
	132	ret = i2c_smbus_read_byte_data(client, CCS811_STATUS);
	133	if (ret < 0)
	134	return ret;
	135
b91e146c RL	136	if ((ret & CCS811_STATUS_FW_MODE_APPLICATION))
	137	return 0;
	138
a94c24a7 NAMV	139	if ((ret & CCS811_STATUS_APP_VALID_MASK) !=
	140	CCS811_STATUS_APP_VALID_LOADED)
	141	return -EIO;
	142
	143	ret = i2c_smbus_write_byte(client, CCS811_APP_START);
	144	if (ret < 0)
	145	return ret;
	146
	147	ret = i2c_smbus_read_byte_data(client, CCS811_STATUS);
	148	if (ret < 0)
	149	return ret;
	150
	151	if ((ret & CCS811_STATUS_FW_MODE_MASK) !=
	152	CCS811_STATUS_FW_MODE_APPLICATION) {
	153	dev_err(&client->dev, "Application failed to start. Sensor is still in boot mode.\n");
	154	return -EIO;
	155	}
	156
	157	return 0;
	158	}
	159
	160	static int ccs811_setup(struct i2c_client *client)
	161	{
	162	int ret;
	163
	164	ret = ccs811_start_sensor_application(client);
	165	if (ret < 0)
	166	return ret;
	167
	168	return i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE,
	169	CCS811_MODE_IAQ_1SEC);
	170	}
	171
	172	static int ccs811_get_measurement(struct ccs811_data *data)
	173	{
	174	int ret, tries = 11;
	175
	176	/* Maximum waiting time: 1s, as measurements are made every second */
	177	while (tries-- > 0) {
	178	ret = i2c_smbus_read_byte_data(data->client, CCS811_STATUS);
	179	if (ret < 0)
	180	return ret;
	181
	182	if ((ret & CCS811_STATUS_DATA_READY) \|\| tries == 0)
	183	break;
	184	msleep(100);
	185	}
	186	if (!(ret & CCS811_STATUS_DATA_READY))
	187	return -EIO;
	188
	189	return i2c_smbus_read_i2c_block_data(data->client,
	190	CCS811_ALG_RESULT_DATA, 8,
	191	(char *)&data->buffer);
	192	}
	193
	194	static int ccs811_read_raw(struct iio_dev *indio_dev,
	195	struct iio_chan_spec const *chan,
	196	int val, int val2, long mask)
	197	{
	198	struct ccs811_data *data = iio_priv(indio_dev);
	199	int ret;
	200
	201	switch (mask) {
	202	case IIO_CHAN_INFO_RAW:
f1f065d7 NAMV	203	ret = iio_device_claim_direct_mode(indio_dev);
	204	if (ret)
	205	return ret;
a94c24a7 NAMV	206	mutex_lock(&data->lock);
	207	ret = ccs811_get_measurement(data);
	208	if (ret < 0) {
	209	mutex_unlock(&data->lock);
f1f065d7	210	iio_device_release_direct_mode(indio_dev);
a94c24a7 NAMV	211	return ret;
	212	}
	213
	214	switch (chan->type) {
	215	case IIO_VOLTAGE:
	216	*val = be16_to_cpu(data->buffer.resistance) &
	217	CCS811_VOLTAGE_MASK;
	218	ret = IIO_VAL_INT;
	219	break;
	220	case IIO_CURRENT:
	221	*val = be16_to_cpu(data->buffer.resistance) >> 10;
	222	ret = IIO_VAL_INT;
	223	break;
	224	case IIO_CONCENTRATION:
	225	switch (chan->channel2) {
	226	case IIO_MOD_CO2:
	227	*val = be16_to_cpu(data->buffer.co2);
	228	ret = IIO_VAL_INT;
	229	break;
	230	case IIO_MOD_VOC:
	231	*val = be16_to_cpu(data->buffer.voc);
	232	ret = IIO_VAL_INT;
	233	break;
	234	default:
	235	ret = -EINVAL;
	236	}
	237	break;
	238	default:
	239	ret = -EINVAL;
	240	}
	241	mutex_unlock(&data->lock);
f1f065d7	242	iio_device_release_direct_mode(indio_dev);
a94c24a7 NAMV	243
	244	return ret;
	245
	246	case IIO_CHAN_INFO_SCALE:
	247	switch (chan->type) {
	248	case IIO_VOLTAGE:
	249	*val = 1;
	250	*val2 = 612903;
	251	return IIO_VAL_INT_PLUS_MICRO;
	252	case IIO_CURRENT:
	253	*val = 0;
	254	*val2 = 1000;
	255	return IIO_VAL_INT_PLUS_MICRO;
	256	case IIO_CONCENTRATION:
	257	switch (chan->channel2) {
	258	case IIO_MOD_CO2:
	259	*val = 0;
8f114acd	260	*val2 = 100;
a94c24a7 NAMV	261	return IIO_VAL_INT_PLUS_MICRO;
	262	case IIO_MOD_VOC:
	263	*val = 0;
8f114acd NAMV	264	*val2 = 100;
8f114acd NAMV	265	return IIO_VAL_INT_PLUS_NANO;
a94c24a7 NAMV	266	default:
	267	return -EINVAL;
	268	}
	269	default:
	270	return -EINVAL;
	271	}
a94c24a7 NAMV	272	default:
	273	return -EINVAL;
	274	}
	275	}
	276
	277	static const struct iio_info ccs811_info = {
	278	.read_raw = ccs811_read_raw,
a94c24a7 NAMV	279	};
a94c24a7 NAMV	280
f1f065d7 NAMV	281	static int ccs811_set_trigger_state(struct iio_trigger *trig,
	282	bool state)
	283	{
	284	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	285	struct ccs811_data *data = iio_priv(indio_dev);
	286	int ret;
	287
	288	ret = i2c_smbus_read_byte_data(data->client, CCS811_MEAS_MODE);
	289	if (ret < 0)
	290	return ret;
	291
	292	if (state)
	293	ret \|= CCS811_MEAS_MODE_INTERRUPT;
	294	else
	295	ret &= ~CCS811_MEAS_MODE_INTERRUPT;
	296
	297	data->drdy_trig_on = state;
	298
	299	return i2c_smbus_write_byte_data(data->client, CCS811_MEAS_MODE, ret);
	300	}
	301
	302	static const struct iio_trigger_ops ccs811_trigger_ops = {
	303	.set_trigger_state = ccs811_set_trigger_state,
	304	};
	305
283d2691 NAMV	306	static irqreturn_t ccs811_trigger_handler(int irq, void *p)
	307	{
	308	struct iio_poll_func *pf = p;
	309	struct iio_dev *indio_dev = pf->indio_dev;
	310	struct ccs811_data *data = iio_priv(indio_dev);
	311	struct i2c_client *client = data->client;
	312	s16 buf[8]; /* s16 eCO2 + s16 TVOC + padding + 8 byte timestamp */
	313	int ret;
	314
	315	ret = i2c_smbus_read_i2c_block_data(client, CCS811_ALG_RESULT_DATA, 4,
	316	(u8 *)&buf);
	317	if (ret != 4) {
	318	dev_err(&client->dev, "cannot read sensor data\n");
	319	goto err;
	320	}
	321
	322	iio_push_to_buffers_with_timestamp(indio_dev, buf,
	323	iio_get_time_ns(indio_dev));
	324
	325	err:
	326	iio_trigger_notify_done(indio_dev->trig);
	327
	328	return IRQ_HANDLED;
	329	}
	330
f1f065d7 NAMV	331	static irqreturn_t ccs811_data_rdy_trigger_poll(int irq, void *private)
	332	{
	333	struct iio_dev *indio_dev = private;
	334	struct ccs811_data *data = iio_priv(indio_dev);
	335
	336	if (data->drdy_trig_on)
	337	iio_trigger_poll(data->drdy_trig);
	338
	339	return IRQ_HANDLED;
	340	}
	341
a94c24a7 NAMV	342	static int ccs811_probe(struct i2c_client *client,
	343	const struct i2c_device_id *id)
	344	{
	345	struct iio_dev *indio_dev;
	346	struct ccs811_data *data;
	347	int ret;
	348
	349	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE
	350	\| I2C_FUNC_SMBUS_BYTE_DATA
	351	\| I2C_FUNC_SMBUS_READ_I2C_BLOCK))
	352	return -EOPNOTSUPP;
	353
	354	/* Check hardware id (should be 0x81 for this family of devices) */
	355	ret = i2c_smbus_read_byte_data(client, CCS811_HW_ID);
	356	if (ret < 0)
	357	return ret;
	358
	359	if (ret != CCS881_HW_ID_VALUE) {
	360	dev_err(&client->dev, "hardware id doesn't match CCS81x\n");
	361	return -ENODEV;
	362	}
	363
	364	ret = i2c_smbus_read_byte_data(client, CCS811_HW_VERSION);
	365	if (ret < 0)
	366	return ret;
	367
	368	if ((ret & CCS811_HW_VERSION_MASK) != CCS811_HW_VERSION_VALUE) {
	369	dev_err(&client->dev, "no CCS811 sensor\n");
	370	return -ENODEV;
	371	}
	372
	373	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	374	if (!indio_dev)
	375	return -ENOMEM;
	376
	377	ret = ccs811_setup(client);
	378	if (ret < 0)
	379	return ret;
	380
	381	data = iio_priv(indio_dev);
	382	i2c_set_clientdata(client, indio_dev);
	383	data->client = client;
	384
	385	mutex_init(&data->lock);
	386
	387	indio_dev->dev.parent = &client->dev;
	388	indio_dev->name = id->name;
	389	indio_dev->info = &ccs811_info;
f1f065d7	390	indio_dev->modes = INDIO_DIRECT_MODE;
a94c24a7 NAMV	391
	392	indio_dev->channels = ccs811_channels;
	393	indio_dev->num_channels = ARRAY_SIZE(ccs811_channels);
	394
f1f065d7 NAMV	395	if (client->irq > 0) {
	396	ret = devm_request_threaded_irq(&client->dev, client->irq,
	397	ccs811_data_rdy_trigger_poll,
	398	NULL,
	399	IRQF_TRIGGER_FALLING \|
	400	IRQF_ONESHOT,
	401	"ccs811_irq", indio_dev);
	402	if (ret) {
	403	dev_err(&client->dev, "irq request error %d\n", -ret);
	404	goto err_poweroff;
	405	}
	406
	407	data->drdy_trig = devm_iio_trigger_alloc(&client->dev,
	408	"%s-dev%d",
	409	indio_dev->name,
	410	indio_dev->id);
	411	if (!data->drdy_trig) {
	412	ret = -ENOMEM;
	413	goto err_poweroff;
	414	}
	415
	416	data->drdy_trig->dev.parent = &client->dev;
	417	data->drdy_trig->ops = &ccs811_trigger_ops;
	418	iio_trigger_set_drvdata(data->drdy_trig, indio_dev);
	419	indio_dev->trig = data->drdy_trig;
	420	iio_trigger_get(indio_dev->trig);
	421	ret = iio_trigger_register(data->drdy_trig);
	422	if (ret)
	423	goto err_poweroff;
	424	}
	425
283d2691 NAMV	426	ret = iio_triggered_buffer_setup(indio_dev, NULL,
	427	ccs811_trigger_handler, NULL);
	428
	429	if (ret < 0) {
	430	dev_err(&client->dev, "triggered buffer setup failed\n");
f1f065d7	431	goto err_trigger_unregister;
283d2691 NAMV	432	}
	433
	434	ret = iio_device_register(indio_dev);
	435	if (ret < 0) {
	436	dev_err(&client->dev, "unable to register iio device\n");
	437	goto err_buffer_cleanup;
	438	}
	439	return 0;
	440
	441	err_buffer_cleanup:
	442	iio_triggered_buffer_cleanup(indio_dev);
f1f065d7 NAMV	443	err_trigger_unregister:
	444	if (data->drdy_trig)
	445	iio_trigger_unregister(data->drdy_trig);
283d2691 NAMV	446	err_poweroff:
	447	i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE, CCS811_MODE_IDLE);
	448
	449	return ret;
a94c24a7 NAMV	450	}
	451
	452	static int ccs811_remove(struct i2c_client *client)
	453	{
	454	struct iio_dev *indio_dev = i2c_get_clientdata(client);
f1f065d7	455	struct ccs811_data *data = iio_priv(indio_dev);
a94c24a7 NAMV	456
a94c24a7 NAMV	457	iio_device_unregister(indio_dev);
283d2691	458	iio_triggered_buffer_cleanup(indio_dev);
f1f065d7 NAMV	459	if (data->drdy_trig)
f1f065d7 NAMV	460	iio_trigger_unregister(data->drdy_trig);
a94c24a7 NAMV	461
	462	return i2c_smbus_write_byte_data(client, CCS811_MEAS_MODE,
	463	CCS811_MODE_IDLE);
	464	}
	465
	466	static const struct i2c_device_id ccs811_id[] = {
	467	{"ccs811", 0},
	468	{ }
	469	};
	470	MODULE_DEVICE_TABLE(i2c, ccs811_id);
	471
	472	static struct i2c_driver ccs811_driver = {
	473	.driver = {
	474	.name = "ccs811",
	475	},
	476	.probe = ccs811_probe,
	477	.remove = ccs811_remove,
	478	.id_table = ccs811_id,
	479	};
	480	module_i2c_driver(ccs811_driver);
	481
	482	MODULE_AUTHOR("Narcisa Vasile <narcisaanamaria12@gmail.com>");
	483	MODULE_DESCRIPTION("CCS811 volatile organic compounds sensor");
	484	MODULE_LICENSE("GPL v2");