Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 489 insertions, 0 deletions

diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c
new file mode 100644
index 000000000..46d5d48b5
--- /dev/null
+++ b/drivers/iio/chemical/ccs811.c
@@ -0,0 +1,489 @@
+/*
+ * 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 CCS811_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 raw_data;
+} __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;
+	/* Ensures correct alignment of timestamp if present */
+	struct {
+		s16 channels[2];
+		s64 ts __aligned(8);
+	} scan;
+};
+
+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.raw_data) &
+					   CCS811_VOLTAGE_MASK;
+			ret = IIO_VAL_INT;
+			break;
+		case IIO_CURRENT:
+			*val = be16_to_cpu(data->buffer.raw_data) >> 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;
+	int ret;
+
+	ret = i2c_smbus_read_i2c_block_data(client, CCS811_ALG_RESULT_DATA,
+					    sizeof(data->scan.channels),
+					    (u8 *)data->scan.channels);
+	if (ret != 4) {
+		dev_err(&client->dev, "cannot read sensor data\n");
+		goto err;
+	}
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
+					   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 != CCS811_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");