Commit 0115a63c authored by Eugene Zaikonnikov's avatar Eugene Zaikonnikov Committed by Jonathan Cameron
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iio: humidity: Add TI HDC20x0 support



Add driver support for HDC2010/2080 series devices and sysfs
documentation for their heater element.

HDC2010 is an integrated high-accuracy humidity and temperature sensor
with very low power consumption. The device includes a resistive heating
element. The temperature range is -40C to 125C with 0.2C
accuracy. Humidity measurement is 0 to 100% with 2% RH accuracy.

Signed-off-by: default avatarEugene Zaikonnikov <ez@norphonic.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent fe184be8
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What:		/sys/bus/iio/devices/iio:deviceX/out_current_heater_raw
What:		/sys/bus/iio/devices/iio:deviceX/out_current_heater_raw_available
KernelVersion:	5.3.8
Contact:	linux-iio@vger.kernel.org
Description:
		Controls the heater device within the humidity sensor to get
		rid of excess condensation.

		Valid control values are 0 = OFF, and 1 = ON.
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@@ -38,6 +38,16 @@ config HDC100X
	  To compile this driver as a module, choose M here: the module
	  will be called hdc100x.

config HDC2010
	tristate "TI HDC2010 relative humidity and temperature sensor"
	depends on I2C
	help
	  Say yes here to build support for the Texas Instruments
	  HDC2010 and HDC2080 relative humidity and temperature sensors.

	  To compile this driver as a module, choose M here: the module
	  will be called hdc2010.

config HID_SENSOR_HUMIDITY
	tristate "HID Environmental humidity sensor"
	depends on HID_SENSOR_HUB
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@@ -6,6 +6,7 @@
obj-$(CONFIG_AM2315) += am2315.o
obj-$(CONFIG_DHT11) += dht11.o
obj-$(CONFIG_HDC100X) += hdc100x.o
obj-$(CONFIG_HDC2010) += hdc2010.o
obj-$(CONFIG_HID_SENSOR_HUMIDITY) += hid-sensor-humidity.o

hts221-y := hts221_core.o \
+353 −0
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// SPDX-License-Identifier: GPL-2.0+
/*
 * hdc2010.c - Support for the TI HDC2010 and HDC2080
 * temperature + relative humidity sensors
 *
 * Copyright (C) 2020 Norphonic AS
 * Author: Eugene Zaikonnikov <ez@norphonic.com>
 *
 * Datasheet: https://www.ti.com/product/HDC2010/datasheet
 * Datasheet: https://www.ti.com/product/HDC2080/datasheet
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/bitops.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

#define HDC2010_REG_TEMP_LOW			0x00
#define HDC2010_REG_TEMP_HIGH			0x01
#define HDC2010_REG_HUMIDITY_LOW		0x02
#define HDC2010_REG_HUMIDITY_HIGH		0x03
#define HDC2010_REG_INTERRUPT_DRDY		0x04
#define HDC2010_REG_TEMP_MAX			0x05
#define HDC2010_REG_HUMIDITY_MAX		0x06
#define HDC2010_REG_INTERRUPT_EN		0x07
#define HDC2010_REG_TEMP_OFFSET_ADJ		0x08
#define HDC2010_REG_HUMIDITY_OFFSET_ADJ		0x09
#define HDC2010_REG_TEMP_THR_L			0x0a
#define HDC2010_REG_TEMP_THR_H			0x0b
#define HDC2010_REG_RH_THR_L			0x0c
#define HDC2010_REG_RH_THR_H			0x0d
#define HDC2010_REG_RESET_DRDY_INT_CONF		0x0e
#define HDC2010_REG_MEASUREMENT_CONF		0x0f

#define HDC2010_MEAS_CONF			GENMASK(2, 1)
#define HDC2010_MEAS_TRIG			BIT(0)
#define HDC2010_HEATER_EN			BIT(3)
#define HDC2010_AMM				GENMASK(6, 4)

struct hdc2010_data {
	struct i2c_client *client;
	struct mutex lock;
	u8 measurement_config;
	u8 interrupt_config;
	u8 drdy_config;
};

enum hdc2010_addr_groups {
	HDC2010_GROUP_TEMP = 0,
	HDC2010_GROUP_HUMIDITY,
};

struct hdc2010_reg_record {
	unsigned long primary;
	unsigned long peak;
};

static const struct hdc2010_reg_record hdc2010_reg_translation[] = {
	[HDC2010_GROUP_TEMP] = {
		.primary = HDC2010_REG_TEMP_LOW,
		.peak = HDC2010_REG_TEMP_MAX,
	},
	[HDC2010_GROUP_HUMIDITY] = {
		.primary = HDC2010_REG_HUMIDITY_LOW,
		.peak = HDC2010_REG_HUMIDITY_MAX,
	},
};

static IIO_CONST_ATTR(out_current_heater_raw_available, "0 1");

static struct attribute *hdc2010_attributes[] = {
	&iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
	NULL
};

static const struct attribute_group hdc2010_attribute_group = {
	.attrs = hdc2010_attributes,
};

static const struct iio_chan_spec hdc2010_channels[] = {
	{
		.type = IIO_TEMP,
		.address = HDC2010_GROUP_TEMP,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
			BIT(IIO_CHAN_INFO_PEAK) |
			BIT(IIO_CHAN_INFO_OFFSET) |
			BIT(IIO_CHAN_INFO_SCALE),
	},
	{
		.type = IIO_HUMIDITYRELATIVE,
		.address = HDC2010_GROUP_HUMIDITY,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
			BIT(IIO_CHAN_INFO_PEAK) |
			BIT(IIO_CHAN_INFO_SCALE),
	},
	{
		.type = IIO_CURRENT,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
		.extend_name = "heater",
		.output = 1,
	},
};

static int hdc2010_update_drdy_config(struct hdc2010_data *data,
					     char mask, char val)
{
	u8 tmp = (~mask & data->drdy_config) | val;
	int ret;

	ret = i2c_smbus_write_byte_data(data->client,
					HDC2010_REG_RESET_DRDY_INT_CONF, tmp);
	if (ret)
		return ret;

	data->drdy_config = tmp;

	return 0;
}

static int hdc2010_get_prim_measurement_word(struct hdc2010_data *data,
					     struct iio_chan_spec const *chan)
{
	struct i2c_client *client = data->client;
	s32 ret;

	ret = i2c_smbus_read_word_data(client,
			hdc2010_reg_translation[chan->address].primary);

	if (ret < 0)
		dev_err(&client->dev, "Could not read sensor measurement word\n");

	return ret;
}

static int hdc2010_get_peak_measurement_byte(struct hdc2010_data *data,
					     struct iio_chan_spec const *chan)
{
	struct i2c_client *client = data->client;
	s32 ret;

	ret = i2c_smbus_read_byte_data(client,
			hdc2010_reg_translation[chan->address].peak);

	if (ret < 0)
		dev_err(&client->dev, "Could not read sensor measurement byte\n");

	return ret;
}

static int hdc2010_get_heater_status(struct hdc2010_data *data)
{
	return !!(data->drdy_config & HDC2010_HEATER_EN);
}

static int hdc2010_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan, int *val,
			    int *val2, long mask)
{
	struct hdc2010_data *data = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW: {
		int ret;

		if (chan->type == IIO_CURRENT) {
			*val = hdc2010_get_heater_status(data);
			return IIO_VAL_INT;
		}
		ret = iio_device_claim_direct_mode(indio_dev);
		if (ret)
			return ret;
		mutex_lock(&data->lock);
		ret = hdc2010_get_prim_measurement_word(data, chan);
		mutex_unlock(&data->lock);
		iio_device_release_direct_mode(indio_dev);
		if (ret < 0)
			return ret;
		*val = ret;
		return IIO_VAL_INT;
	}
	case IIO_CHAN_INFO_PEAK: {
		int ret;

		ret = iio_device_claim_direct_mode(indio_dev);
		if (ret)
			return ret;
		mutex_lock(&data->lock);
		ret = hdc2010_get_peak_measurement_byte(data, chan);
		mutex_unlock(&data->lock);
		iio_device_release_direct_mode(indio_dev);
		if (ret < 0)
			return ret;
		/* Scaling up the value so we can use same offset as RAW */
		*val = ret * 256;
		return IIO_VAL_INT;
	}
	case IIO_CHAN_INFO_SCALE:
		*val2 = 65536;
		if (chan->type == IIO_TEMP)
			*val = 165000;
		else
			*val = 100000;
		return IIO_VAL_FRACTIONAL;
	case IIO_CHAN_INFO_OFFSET:
		*val = -15887;
		*val2 = 515151;
		return IIO_VAL_INT_PLUS_MICRO;
	default:
		return -EINVAL;
	}
}

static int hdc2010_write_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int val, int val2, long mask)
{
	struct hdc2010_data *data = iio_priv(indio_dev);
	int new, ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (chan->type != IIO_CURRENT || val2 != 0)
			return -EINVAL;

		switch (val) {
		case 1:
			new = HDC2010_HEATER_EN;
			break;
		case 0:
			new = 0;
			break;
		default:
			return -EINVAL;
		}

		mutex_lock(&data->lock);
		ret = hdc2010_update_drdy_config(data, HDC2010_HEATER_EN, new);
		mutex_unlock(&data->lock);
		return ret;
	default:
		return -EINVAL;
	}
}

static const struct iio_info hdc2010_info = {
	.read_raw = hdc2010_read_raw,
	.write_raw = hdc2010_write_raw,
	.attrs = &hdc2010_attribute_group,
};

static int hdc2010_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct iio_dev *indio_dev;
	struct hdc2010_data *data;
	u8 tmp;
	int ret;

	if (!i2c_check_functionality(client->adapter,
	    I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
		return -EOPNOTSUPP;

	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;
	mutex_init(&data->lock);

	indio_dev->dev.parent = &client->dev;
	/*
	 * As DEVICE ID register does not differentiate between
	 * HDC2010 and HDC2080, we have the name hardcoded
	 */
	indio_dev->name = "hdc2010";
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->info = &hdc2010_info;

	indio_dev->channels = hdc2010_channels;
	indio_dev->num_channels = ARRAY_SIZE(hdc2010_channels);

	/* Enable Automatic Measurement Mode at 5Hz */
	ret = hdc2010_update_drdy_config(data, HDC2010_AMM, HDC2010_AMM);
	if (ret)
		return ret;

	/*
	 * We enable both temp and humidity measurement.
	 * However the measurement won't start even in AMM until triggered.
	 */
	tmp = (data->measurement_config & ~HDC2010_MEAS_CONF) |
		HDC2010_MEAS_TRIG;

	ret = i2c_smbus_write_byte_data(client, HDC2010_REG_MEASUREMENT_CONF, tmp);
	if (ret) {
		dev_warn(&client->dev, "Unable to set up measurement\n");
		if (hdc2010_update_drdy_config(data, HDC2010_AMM, 0))
			dev_warn(&client->dev, "Unable to restore default AMM\n");
		return ret;
	};

	data->measurement_config = tmp;

	return iio_device_register(indio_dev);
}

static int hdc2010_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct hdc2010_data *data = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);

	/* Disable Automatic Measurement Mode */
	if (hdc2010_update_drdy_config(data, HDC2010_AMM, 0))
		dev_warn(&client->dev, "Unable to restore default AMM\n");

	return 0;
}

static const struct i2c_device_id hdc2010_id[] = {
	{ "hdc2010" },
	{ "hdc2080" },
	{ }
};
MODULE_DEVICE_TABLE(i2c, hdc2010_id);

static const struct of_device_id hdc2010_dt_ids[] = {
	{ .compatible = "ti,hdc2010" },
	{ .compatible = "ti,hdc2080" },
	{ }
};
MODULE_DEVICE_TABLE(of, hdc2010_dt_ids);

static struct i2c_driver hdc2010_driver = {
	.driver = {
		.name	= "hdc2010",
		.of_match_table = hdc2010_dt_ids,
	},
	.probe = hdc2010_probe,
	.remove = hdc2010_remove,
	.id_table = hdc2010_id,
};
module_i2c_driver(hdc2010_driver);

MODULE_AUTHOR("Eugene Zaikonnikov <ez@norphonic.com>");
MODULE_DESCRIPTION("TI HDC2010 humidity and temperature sensor driver");
MODULE_LICENSE("GPL");