[PATCH v2 3/6] iio: chemical: add driver for ENS160 sensor

From: Gustavo Silva
Date: Tue May 28 2024 - 20:15:53 EST


ScioSense ENS160 is a digital metal oxide multi-gas sensor, designed
for indoor air quality monitoring. The driver supports readings of
CO2 and VOC, and can be accessed via both SPI and I2C.

Datasheet: https://www.sciosense.com/wp-content/uploads/2023/12/ENS160-Datasheet.pdf

Signed-off-by: Gustavo Silva <gustavograzs@xxxxxxxxx>
---
changes in v2:
- Make regmap bulk reads DMA safe by adding buffers to the end of
iio_priv() struct and marking it __aligned(IIO_DMA_MINALIGN)
- Remove unnecessary time delays
- Use devm_add_action_or_reset() to register custom cleanup and delete
the remove() function
- Add missing register definition ENS160_REG_DATA_AQI
- Use dev_err_probe() where applicable
- Hardcode device name
- Remove unnecessary dev_set_drvdata() call
- Do not set driver_data to 0 in {spi,i2c}_device_id structs
drivers/iio/chemical/Kconfig | 22 +++
drivers/iio/chemical/Makefile | 3 +
drivers/iio/chemical/ens160.h | 7 +
drivers/iio/chemical/ens160_core.c | 221 +++++++++++++++++++++++++++++
drivers/iio/chemical/ens160_i2c.c | 60 ++++++++
drivers/iio/chemical/ens160_spi.c | 60 ++++++++
6 files changed, 373 insertions(+)
create mode 100644 drivers/iio/chemical/ens160.h
create mode 100644 drivers/iio/chemical/ens160_core.c
create mode 100644 drivers/iio/chemical/ens160_i2c.c
create mode 100644 drivers/iio/chemical/ens160_spi.c

diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
index 02649ab81..e407afab8 100644
--- a/drivers/iio/chemical/Kconfig
+++ b/drivers/iio/chemical/Kconfig
@@ -76,6 +76,28 @@ config CCS811
Say Y here to build I2C interface support for the AMS
CCS811 VOC (Volatile Organic Compounds) sensor

+config ENS160
+ tristate "ScioSense ENS160 sensor driver"
+ depends on (I2C || SPI)
+ select REGMAP
+ select ENS160_I2C if I2C
+ select ENS160_SPI if SPI
+ help
+ Say yes here to build support for ScioSense ENS160 multi-gas sensor.
+
+ This driver can also be built as a module. If so, the module for I2C
+ would be called ens160_i2c and ens160_spi for SPI support.
+
+config ENS160_I2C
+ tristate
+ depends on I2C && ENS160
+ select REGMAP_I2C
+
+config ENS160_SPI
+ tristate
+ depends on SPI && ENS160
+ select REGMAP_SPI
+
config IAQCORE
tristate "AMS iAQ-Core VOC sensors"
depends on I2C
diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
index 2f3dee8bb..4866db06b 100644
--- a/drivers/iio/chemical/Makefile
+++ b/drivers/iio/chemical/Makefile
@@ -11,6 +11,9 @@ obj-$(CONFIG_BME680) += bme680_core.o
obj-$(CONFIG_BME680_I2C) += bme680_i2c.o
obj-$(CONFIG_BME680_SPI) += bme680_spi.o
obj-$(CONFIG_CCS811) += ccs811.o
+obj-$(CONFIG_ENS160) += ens160_core.o
+obj-$(CONFIG_ENS160_I2C) += ens160_i2c.o
+obj-$(CONFIG_ENS160_SPI) += ens160_spi.o
obj-$(CONFIG_IAQCORE) += ams-iaq-core.o
obj-$(CONFIG_PMS7003) += pms7003.o
obj-$(CONFIG_SCD30_CORE) += scd30_core.o
diff --git a/drivers/iio/chemical/ens160.h b/drivers/iio/chemical/ens160.h
new file mode 100644
index 000000000..d0df15f08
--- /dev/null
+++ b/drivers/iio/chemical/ens160.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ENS160_H_
+#define ENS160_H_
+
+int devm_ens160_core_probe(struct device *dev, struct regmap *regmap,
+ const char *name);
+#endif
diff --git a/drivers/iio/chemical/ens160_core.c b/drivers/iio/chemical/ens160_core.c
new file mode 100644
index 000000000..a535f62c4
--- /dev/null
+++ b/drivers/iio/chemical/ens160_core.c
@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ScioSense ENS160 multi-gas sensor driver
+ *
+ * Copyright (c) 2024 Gustavo Silva <gustavograzs@xxxxxxxxx>
+ *
+ * Datasheet:
+ * https://www.sciosense.com/wp-content/uploads/2023/12/ENS160-Datasheet.pdf
+ */
+
+#include <linux/bitfield.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include "ens160.h"
+
+#define ENS160_PART_ID 0x160
+
+#define ENS160_BOOTING_TIME_MS 10U
+
+#define ENS160_REG_PART_ID 0x00
+
+#define ENS160_REG_OPMODE 0x10
+
+#define ENS160_REG_MODE_DEEP_SLEEP 0x00
+#define ENS160_REG_MODE_IDLE 0x01
+#define ENS160_REG_MODE_STANDARD 0x02
+#define ENS160_REG_MODE_RESET 0xF0
+
+#define ENS160_REG_COMMAND 0x12
+#define ENS160_REG_COMMAND_GET_APPVER 0x0E
+#define ENS160_REG_COMMAND_CLRGPR 0xCC
+
+#define ENS160_REG_TEMP_IN 0x13
+#define ENS160_REG_RH_IN 0x15
+#define ENS160_REG_DEVICE_STATUS 0x20
+#define ENS160_REG_DATA_AQI 0x21
+#define ENS160_REG_DATA_TVOC 0x22
+#define ENS160_REG_DATA_ECO2 0x24
+#define ENS160_REG_DATA_T 0x30
+#define ENS160_REG_DATA_RH 0x32
+#define ENS160_REG_GPR_READ4 0x4C
+
+#define ENS160_STATUS_VALIDITY_FLAG GENMASK(3, 2)
+
+#define ENS160_STATUS_NORMAL 0x00
+
+struct ens160_data {
+ struct regmap *regmap;
+ u8 fw_version[3] __aligned(IIO_DMA_MINALIGN);
+ __le16 buf;
+};
+
+static const struct iio_chan_spec ens160_channels[] = {
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_VOC,
+ .modified = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .address = ENS160_REG_DATA_TVOC,
+ },
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_CO2,
+ .modified = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .address = ENS160_REG_DATA_ECO2,
+ },
+};
+
+static int ens160_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct ens160_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = regmap_bulk_read(data->regmap, chan->address,
+ &data->buf, sizeof(data->buf));
+ if (ret)
+ return ret;
+ *val = le16_to_cpu(data->buf);
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->channel2) {
+ case IIO_MOD_CO2:
+ /* The sensor reads CO2 data as ppm */
+ *val = 0;
+ *val2 = 100;
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_MOD_VOC:
+ /* The sensor reads VOC data as ppb */
+ *val = 0;
+ *val2 = 100;
+ return IIO_VAL_INT_PLUS_NANO;
+ default:
+ return -EINVAL;
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ens160_set_mode(struct ens160_data *data, u8 mode)
+{
+ int ret;
+
+ ret = regmap_write(data->regmap, ENS160_REG_OPMODE, mode);
+ if (ret)
+ return ret;
+
+ msleep(ENS160_BOOTING_TIME_MS);
+
+ return 0;
+}
+
+static void ens160_set_idle(void *data)
+{
+ ens160_set_mode(data, ENS160_REG_MODE_IDLE);
+}
+
+static int ens160_chip_init(struct ens160_data *data)
+{
+ struct device *dev = regmap_get_device(data->regmap);
+ unsigned int status;
+ int ret;
+
+ ret = ens160_set_mode(data, ENS160_REG_MODE_RESET);
+ if (ret)
+ return ret;
+
+ ret = regmap_bulk_read(data->regmap, ENS160_REG_PART_ID, &data->buf,
+ sizeof(data->buf));
+ if (ret)
+ return ret;
+
+ if (le16_to_cpu(data->buf) != ENS160_PART_ID)
+ return -ENODEV;
+
+ ret = ens160_set_mode(data, ENS160_REG_MODE_IDLE);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(data->regmap, ENS160_REG_COMMAND,
+ ENS160_REG_COMMAND_CLRGPR);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(data->regmap, ENS160_REG_COMMAND,
+ ENS160_REG_COMMAND_GET_APPVER);
+ if (ret)
+ return ret;
+
+ ret = regmap_bulk_read(data->regmap, ENS160_REG_GPR_READ4,
+ data->fw_version, sizeof(data->fw_version));
+ if (ret)
+ return ret;
+
+ dev_info(dev, "firmware version: %u.%u.%u\n", data->fw_version[2],
+ data->fw_version[1], data->fw_version[0]);
+
+ ret = ens160_set_mode(data, ENS160_REG_MODE_STANDARD);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(data->regmap, ENS160_REG_DEVICE_STATUS, &status);
+ if (ret)
+ return ret;
+
+ if (FIELD_GET(ENS160_STATUS_VALIDITY_FLAG, status)
+ != ENS160_STATUS_NORMAL)
+ return -EINVAL;
+
+ return 0;
+}
+
+static const struct iio_info ens160_info = {
+ .read_raw = ens160_read_raw,
+};
+
+int devm_ens160_core_probe(struct device *dev, struct regmap *regmap,
+ const char *name)
+{
+ struct ens160_data *data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ data->regmap = regmap;
+
+ indio_dev->name = name;
+ indio_dev->info = &ens160_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = ens160_channels;
+ indio_dev->num_channels = ARRAY_SIZE(ens160_channels);
+
+ ret = devm_add_action_or_reset(dev, ens160_set_idle, data);
+ if (ret)
+ return ret;
+
+ ret = ens160_chip_init(data);
+ if (ret)
+ return dev_err_probe(dev, ret, "chip initialization failed\n");
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL_NS(devm_ens160_core_probe, IIO_ENS160);
+
+MODULE_AUTHOR("Gustavo Silva <gustavograzs@xxxxxxxxx>");
+MODULE_DESCRIPTION("ScioSense ENS160 driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/chemical/ens160_i2c.c b/drivers/iio/chemical/ens160_i2c.c
new file mode 100644
index 000000000..2f0b08e52
--- /dev/null
+++ b/drivers/iio/chemical/ens160_i2c.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ScioSense ENS160 multi-gas sensor I2C driver
+ *
+ * Copyright (c) 2024 Gustavo Silva <gustavograzs@xxxxxxxxx>
+ *
+ * 7-Bit I2C slave address is:
+ * - 0x52 if ADDR pin LOW
+ * - 0x53 if ADDR pin HIGH
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include "ens160.h"
+
+static const struct regmap_config ens160_regmap_i2c_conf = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static int ens160_i2c_probe(struct i2c_client *client)
+{
+ struct regmap *regmap;
+
+ regmap = devm_regmap_init_i2c(client, &ens160_regmap_i2c_conf);
+ if (IS_ERR(regmap))
+ return dev_err_probe(&client->dev, PTR_ERR(regmap),
+ "Failed to register i2c regmap\n");
+
+ return devm_ens160_core_probe(&client->dev, regmap, "ens160_i2c");
+}
+
+static const struct i2c_device_id ens160_i2c_id[] = {
+ { "ens160" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ens160_i2c_id);
+
+static const struct of_device_id ens160_of_i2c_match[] = {
+ { .compatible = "sciosense,ens160" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ens160_of_i2c_match);
+
+static struct i2c_driver ens160_i2c_driver = {
+ .driver = {
+ .name = "ens160_i2c",
+ .of_match_table = ens160_of_i2c_match,
+ },
+ .probe = ens160_i2c_probe,
+ .id_table = ens160_i2c_id,
+};
+module_i2c_driver(ens160_i2c_driver);
+
+MODULE_AUTHOR("Gustavo Silva <gustavograzs@xxxxxxxxx>");
+MODULE_DESCRIPTION("ScioSense ENS160 I2C driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS(IIO_ENS160);
diff --git a/drivers/iio/chemical/ens160_spi.c b/drivers/iio/chemical/ens160_spi.c
new file mode 100644
index 000000000..9a6c9c7e3
--- /dev/null
+++ b/drivers/iio/chemical/ens160_spi.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ScioSense ENS160 multi-gas sensor SPI driver
+ *
+ * Copyright (c) 2024 Gustavo Silva <gustavograzs@xxxxxxxxx>
+ */
+
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include "ens160.h"
+
+#define ENS160_SPI_READ BIT(0)
+
+static const struct regmap_config ens160_regmap_spi_conf = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .reg_shift = -1,
+ .read_flag_mask = ENS160_SPI_READ,
+};
+
+static int ens160_spi_probe(struct spi_device *spi)
+{
+ struct regmap *regmap;
+
+ regmap = devm_regmap_init_spi(spi, &ens160_regmap_spi_conf);
+ if (IS_ERR(regmap))
+ return dev_err_probe(&spi->dev, PTR_ERR(regmap),
+ "Failed to register spi regmap\n");
+
+ return devm_ens160_core_probe(&spi->dev, regmap, "ens160_spi");
+}
+
+static const struct of_device_id ens160_spi_of_match[] = {
+ { .compatible = "sciosense,ens160" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ens160_spi_of_match);
+
+static const struct spi_device_id ens160_spi_id[] = {
+ { "ens160" },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ens160_spi_id);
+
+static struct spi_driver ens160_spi_driver = {
+ .driver = {
+ .name = "ens160_spi",
+ .of_match_table = ens160_spi_of_match,
+ },
+ .probe = ens160_spi_probe,
+ .id_table = ens160_spi_id,
+};
+module_spi_driver(ens160_spi_driver);
+
+MODULE_AUTHOR("Gustavo Silva <gustavograzs@xxxxxxxxx>");
+MODULE_DESCRIPTION("ScioSense ENS160 SPI driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS(IIO_ENS160);
--
2.45.1