| Message ID | 20200603084441.33952-4-tomasz.duszynski@octakon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add support for SCD30 sensor | expand |
On Wed, Jun 3, 2020 at 11:47 AM Tomasz Duszynski <tomasz.duszynski@octakon.com> wrote: > > Add serial interface driver for the SCD30 sensor. FWIW, Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > Signed-off-by: Tomasz Duszynski <tomasz.duszynski@octakon.com> > --- > MAINTAINERS | 1 + > drivers/iio/chemical/Kconfig | 11 ++ > drivers/iio/chemical/Makefile | 1 + > drivers/iio/chemical/scd30_serial.c | 263 ++++++++++++++++++++++++++++ > 4 files changed, 276 insertions(+) > create mode 100644 drivers/iio/chemical/scd30_serial.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 13aed3473b7e..5db4b446c8ba 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -15143,6 +15143,7 @@ S: Maintained > F: drivers/iio/chemical/scd30.h > F: drivers/iio/chemical/scd30_core.c > F: drivers/iio/chemical/scd30_i2c.c > +F: drivers/iio/chemical/scd30_serial.c > > SENSIRION SPS30 AIR POLLUTION SENSOR DRIVER > M: Tomasz Duszynski <tduszyns@gmail.com> > diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig > index 970d34888c2e..10bb431bc3ce 100644 > --- a/drivers/iio/chemical/Kconfig > +++ b/drivers/iio/chemical/Kconfig > @@ -107,6 +107,17 @@ config SCD30_I2C > To compile this driver as a module, choose M here: the module will > be called scd30_i2c. > > +config SCD30_SERIAL > + tristate "SCD30 carbon dioxide sensor serial driver" > + depends on SCD30_CORE && SERIAL_DEV_BUS > + select CRC16 > + help > + Say Y here to build support for the Sensirion SCD30 serial interface > + driver. > + > + To compile this driver as a module, choose M here: the module will > + be called scd30_serial. > + > config SENSIRION_SGP30 > tristate "Sensirion SGPxx gas sensors" > depends on I2C > diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile > index 0966ca34e34b..fef63dd5bf92 100644 > --- a/drivers/iio/chemical/Makefile > +++ b/drivers/iio/chemical/Makefile > @@ -14,6 +14,7 @@ obj-$(CONFIG_IAQCORE) += ams-iaq-core.o > obj-$(CONFIG_PMS7003) += pms7003.o > obj-$(CONFIG_SCD30_CORE) += scd30_core.o > obj-$(CONFIG_SCD30_I2C) += scd30_i2c.o > +obj-$(CONFIG_SCD30_SERIAL) += scd30_serial.o > obj-$(CONFIG_SENSIRION_SGP30) += sgp30.o > obj-$(CONFIG_SPS30) += sps30.o > obj-$(CONFIG_VZ89X) += vz89x.o > diff --git a/drivers/iio/chemical/scd30_serial.c b/drivers/iio/chemical/scd30_serial.c > new file mode 100644 > index 000000000000..06f85eb1a4dd > --- /dev/null > +++ b/drivers/iio/chemical/scd30_serial.c > @@ -0,0 +1,263 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Sensirion SCD30 carbon dioxide sensor serial driver > + * > + * Copyright (c) 2020 Tomasz Duszynski <tomasz.duszynski@octakon.com> > + */ > +#include <linux/crc16.h> > +#include <linux/device.h> > +#include <linux/errno.h> > +#include <linux/iio/iio.h> > +#include <linux/jiffies.h> > +#include <linux/mod_devicetable.h> > +#include <linux/module.h> > +#include <linux/property.h> > +#include <linux/serdev.h> > +#include <linux/string.h> > +#include <linux/types.h> > +#include <asm/unaligned.h> > + > +#include "scd30.h" > + > +#define SCD30_SERDEV_ADDR 0x61 > +#define SCD30_SERDEV_WRITE 0x06 > +#define SCD30_SERDEV_READ 0x03 > +#define SCD30_SERDEV_MAX_BUF_SIZE 17 > +#define SCD30_SERDEV_RX_HEADER_SIZE 3 > +#define SCD30_SERDEV_CRC_SIZE 2 > +#define SCD30_SERDEV_TIMEOUT msecs_to_jiffies(200) > + > +struct scd30_serdev_priv { > + struct completion meas_ready; > + char *buf; > + int num_expected; > + int num; > +}; > + > +static u16 scd30_serdev_cmd_lookup_tbl[] = { > + [CMD_START_MEAS] = 0x0036, > + [CMD_STOP_MEAS] = 0x0037, > + [CMD_MEAS_INTERVAL] = 0x0025, > + [CMD_MEAS_READY] = 0x0027, > + [CMD_READ_MEAS] = 0x0028, > + [CMD_ASC] = 0x003a, > + [CMD_FRC] = 0x0039, > + [CMD_TEMP_OFFSET] = 0x003b, > + [CMD_FW_VERSION] = 0x0020, > + [CMD_RESET] = 0x0034, > +}; > + > +static u16 scd30_serdev_calc_crc(const char *buf, int size) > +{ > + return crc16(0xffff, buf, size); > +} > + > +static int scd30_serdev_xfer(struct scd30_state *state, char *txbuf, int txsize, > + char *rxbuf, int rxsize) > +{ > + struct serdev_device *serdev = to_serdev_device(state->dev); > + struct scd30_serdev_priv *priv = state->priv; > + int ret; > + > + priv->buf = rxbuf; > + priv->num_expected = rxsize; > + priv->num = 0; > + > + ret = serdev_device_write(serdev, txbuf, txsize, SCD30_SERDEV_TIMEOUT); > + if (ret < 0) > + return ret; > + if (ret != txsize) > + return -EIO; > + > + ret = wait_for_completion_interruptible_timeout(&priv->meas_ready, SCD30_SERDEV_TIMEOUT); > + if (ret < 0) > + return ret; > + if (!ret) > + return -ETIMEDOUT; > + > + return 0; > +} > + > +static int scd30_serdev_command(struct scd30_state *state, enum scd30_cmd cmd, u16 arg, > + void *response, int size) > +{ > + /* > + * Communication over serial line is based on modbus protocol (or rather > + * its variation called modbus over serial to be precise). Upon > + * receiving a request device should reply with response. > + * > + * Frame below represents a request message. Each field takes > + * exactly one byte. > + * > + * +------+------+-----+-----+-------+-------+-----+-----+ > + * | dev | op | reg | reg | byte1 | byte0 | crc | crc | > + * | addr | code | msb | lsb | | | lsb | msb | > + * +------+------+-----+-----+-------+-------+-----+-----+ > + * > + * The message device replies with depends on the 'op code' field from > + * the request. In case it was set to SCD30_SERDEV_WRITE sensor should > + * reply with unchanged request. Otherwise 'op code' was set to > + * SCD30_SERDEV_READ and response looks like the one below. As with > + * request, each field takes one byte. > + * > + * +------+------+--------+-------+-----+-------+-----+-----+ > + * | dev | op | num of | byte0 | ... | byteN | crc | crc | > + * | addr | code | bytes | | | | lsb | msb | > + * +------+------+--------+-------+-----+-------+-----+-----+ > + */ > + char txbuf[SCD30_SERDEV_MAX_BUF_SIZE] = { SCD30_SERDEV_ADDR }, > + rxbuf[SCD30_SERDEV_MAX_BUF_SIZE]; > + int ret, rxsize, txsize = 2; > + char *rsp = response; > + u16 crc; > + > + put_unaligned_be16(scd30_serdev_cmd_lookup_tbl[cmd], txbuf + txsize); > + txsize += 2; > + > + if (rsp) { > + txbuf[1] = SCD30_SERDEV_READ; > + if (cmd == CMD_READ_MEAS) > + /* number of u16 words to read */ > + put_unaligned_be16(size / 2, txbuf + txsize); > + else > + put_unaligned_be16(0x0001, txbuf + txsize); > + txsize += 2; > + crc = scd30_serdev_calc_crc(txbuf, txsize); > + put_unaligned_le16(crc, txbuf + txsize); > + txsize += 2; > + rxsize = SCD30_SERDEV_RX_HEADER_SIZE + size + SCD30_SERDEV_CRC_SIZE; > + } else { > + if ((cmd == CMD_STOP_MEAS) || (cmd == CMD_RESET)) > + arg = 0x0001; > + > + txbuf[1] = SCD30_SERDEV_WRITE; > + put_unaligned_be16(arg, txbuf + txsize); > + txsize += 2; > + crc = scd30_serdev_calc_crc(txbuf, txsize); > + put_unaligned_le16(crc, txbuf + txsize); > + txsize += 2; > + rxsize = txsize; > + } > + > + ret = scd30_serdev_xfer(state, txbuf, txsize, rxbuf, rxsize); > + if (ret) > + return ret; > + > + switch (txbuf[1]) { > + case SCD30_SERDEV_WRITE: > + if (memcmp(txbuf, rxbuf, txsize)) { > + dev_err(state->dev, "wrong message received\n"); > + return -EIO; > + } > + break; > + case SCD30_SERDEV_READ: > + if (rxbuf[2] != (rxsize - SCD30_SERDEV_RX_HEADER_SIZE - SCD30_SERDEV_CRC_SIZE)) { > + dev_err(state->dev, "received data size does not match header\n"); > + return -EIO; > + } > + > + rxsize -= SCD30_SERDEV_CRC_SIZE; > + crc = get_unaligned_le16(rxbuf + rxsize); > + if (crc != scd30_serdev_calc_crc(rxbuf, rxsize)) { > + dev_err(state->dev, "data integrity check failed\n"); > + return -EIO; > + } > + > + rxsize -= SCD30_SERDEV_RX_HEADER_SIZE; > + memcpy(rsp, rxbuf + SCD30_SERDEV_RX_HEADER_SIZE, rxsize); > + break; > + default: > + dev_err(state->dev, "received unknown op code\n"); > + return -EIO; > + } > + > + return 0; > +} > + > +static int scd30_serdev_receive_buf(struct serdev_device *serdev, > + const unsigned char *buf, size_t size) > +{ > + struct iio_dev *indio_dev = dev_get_drvdata(&serdev->dev); > + struct scd30_serdev_priv *priv; > + struct scd30_state *state; > + int num; > + > + if (!indio_dev) > + return 0; > + > + state = iio_priv(indio_dev); > + priv = state->priv; > + > + /* just in case sensor puts some unexpected bytes on the bus */ > + if (!priv->buf) > + return 0; > + > + if (priv->num + size >= priv->num_expected) > + num = priv->num_expected - priv->num; > + else > + num = size; > + > + memcpy(priv->buf + priv->num, buf, num); > + priv->num += num; > + > + if (priv->num == priv->num_expected) { > + priv->buf = NULL; > + complete(&priv->meas_ready); > + } > + > + return num; > +} > + > +static const struct serdev_device_ops scd30_serdev_ops = { > + .receive_buf = scd30_serdev_receive_buf, > + .write_wakeup = serdev_device_write_wakeup, > +}; > + > +static int scd30_serdev_probe(struct serdev_device *serdev) > +{ > + struct device *dev = &serdev->dev; > + struct scd30_serdev_priv *priv; > + int irq, ret; > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + init_completion(&priv->meas_ready); > + serdev_device_set_client_ops(serdev, &scd30_serdev_ops); > + > + ret = devm_serdev_device_open(dev, serdev); > + if (ret) > + return ret; > + > + serdev_device_set_baudrate(serdev, 19200); > + serdev_device_set_flow_control(serdev, false); > + > + ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE); > + if (ret) > + return ret; > + > + irq = fwnode_irq_get(dev_fwnode(dev), 0); > + > + return scd30_probe(dev, irq, KBUILD_MODNAME, priv, scd30_serdev_command); > +} > + > +static const struct of_device_id scd30_serdev_of_match[] = { > + { .compatible = "sensirion,scd30" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, scd30_serdev_of_match); > + > +static struct serdev_device_driver scd30_serdev_driver = { > + .driver = { > + .name = KBUILD_MODNAME, > + .of_match_table = scd30_serdev_of_match, > + .pm = &scd30_pm_ops, > + }, > + .probe = scd30_serdev_probe, > +}; > +module_serdev_device_driver(scd30_serdev_driver); > + > +MODULE_AUTHOR("Tomasz Duszynski <tomasz.duszynski@octakon.com>"); > +MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor serial driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.27.0 >
diff --git a/MAINTAINERS b/MAINTAINERS index 13aed3473b7e..5db4b446c8ba 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15143,6 +15143,7 @@ S: Maintained F: drivers/iio/chemical/scd30.h F: drivers/iio/chemical/scd30_core.c F: drivers/iio/chemical/scd30_i2c.c +F: drivers/iio/chemical/scd30_serial.c SENSIRION SPS30 AIR POLLUTION SENSOR DRIVER M: Tomasz Duszynski <tduszyns@gmail.com> diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig index 970d34888c2e..10bb431bc3ce 100644 --- a/drivers/iio/chemical/Kconfig +++ b/drivers/iio/chemical/Kconfig @@ -107,6 +107,17 @@ config SCD30_I2C To compile this driver as a module, choose M here: the module will be called scd30_i2c. +config SCD30_SERIAL + tristate "SCD30 carbon dioxide sensor serial driver" + depends on SCD30_CORE && SERIAL_DEV_BUS + select CRC16 + help + Say Y here to build support for the Sensirion SCD30 serial interface + driver. + + To compile this driver as a module, choose M here: the module will + be called scd30_serial. + config SENSIRION_SGP30 tristate "Sensirion SGPxx gas sensors" depends on I2C diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile index 0966ca34e34b..fef63dd5bf92 100644 --- a/drivers/iio/chemical/Makefile +++ b/drivers/iio/chemical/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_IAQCORE) += ams-iaq-core.o obj-$(CONFIG_PMS7003) += pms7003.o obj-$(CONFIG_SCD30_CORE) += scd30_core.o obj-$(CONFIG_SCD30_I2C) += scd30_i2c.o +obj-$(CONFIG_SCD30_SERIAL) += scd30_serial.o obj-$(CONFIG_SENSIRION_SGP30) += sgp30.o obj-$(CONFIG_SPS30) += sps30.o obj-$(CONFIG_VZ89X) += vz89x.o diff --git a/drivers/iio/chemical/scd30_serial.c b/drivers/iio/chemical/scd30_serial.c new file mode 100644 index 000000000000..06f85eb1a4dd --- /dev/null +++ b/drivers/iio/chemical/scd30_serial.c @@ -0,0 +1,263 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Sensirion SCD30 carbon dioxide sensor serial driver + * + * Copyright (c) 2020 Tomasz Duszynski <tomasz.duszynski@octakon.com> + */ +#include <linux/crc16.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/iio/iio.h> +#include <linux/jiffies.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/property.h> +#include <linux/serdev.h> +#include <linux/string.h> +#include <linux/types.h> +#include <asm/unaligned.h> + +#include "scd30.h" + +#define SCD30_SERDEV_ADDR 0x61 +#define SCD30_SERDEV_WRITE 0x06 +#define SCD30_SERDEV_READ 0x03 +#define SCD30_SERDEV_MAX_BUF_SIZE 17 +#define SCD30_SERDEV_RX_HEADER_SIZE 3 +#define SCD30_SERDEV_CRC_SIZE 2 +#define SCD30_SERDEV_TIMEOUT msecs_to_jiffies(200) + +struct scd30_serdev_priv { + struct completion meas_ready; + char *buf; + int num_expected; + int num; +}; + +static u16 scd30_serdev_cmd_lookup_tbl[] = { + [CMD_START_MEAS] = 0x0036, + [CMD_STOP_MEAS] = 0x0037, + [CMD_MEAS_INTERVAL] = 0x0025, + [CMD_MEAS_READY] = 0x0027, + [CMD_READ_MEAS] = 0x0028, + [CMD_ASC] = 0x003a, + [CMD_FRC] = 0x0039, + [CMD_TEMP_OFFSET] = 0x003b, + [CMD_FW_VERSION] = 0x0020, + [CMD_RESET] = 0x0034, +}; + +static u16 scd30_serdev_calc_crc(const char *buf, int size) +{ + return crc16(0xffff, buf, size); +} + +static int scd30_serdev_xfer(struct scd30_state *state, char *txbuf, int txsize, + char *rxbuf, int rxsize) +{ + struct serdev_device *serdev = to_serdev_device(state->dev); + struct scd30_serdev_priv *priv = state->priv; + int ret; + + priv->buf = rxbuf; + priv->num_expected = rxsize; + priv->num = 0; + + ret = serdev_device_write(serdev, txbuf, txsize, SCD30_SERDEV_TIMEOUT); + if (ret < 0) + return ret; + if (ret != txsize) + return -EIO; + + ret = wait_for_completion_interruptible_timeout(&priv->meas_ready, SCD30_SERDEV_TIMEOUT); + if (ret < 0) + return ret; + if (!ret) + return -ETIMEDOUT; + + return 0; +} + +static int scd30_serdev_command(struct scd30_state *state, enum scd30_cmd cmd, u16 arg, + void *response, int size) +{ + /* + * Communication over serial line is based on modbus protocol (or rather + * its variation called modbus over serial to be precise). Upon + * receiving a request device should reply with response. + * + * Frame below represents a request message. Each field takes + * exactly one byte. + * + * +------+------+-----+-----+-------+-------+-----+-----+ + * | dev | op | reg | reg | byte1 | byte0 | crc | crc | + * | addr | code | msb | lsb | | | lsb | msb | + * +------+------+-----+-----+-------+-------+-----+-----+ + * + * The message device replies with depends on the 'op code' field from + * the request. In case it was set to SCD30_SERDEV_WRITE sensor should + * reply with unchanged request. Otherwise 'op code' was set to + * SCD30_SERDEV_READ and response looks like the one below. As with + * request, each field takes one byte. + * + * +------+------+--------+-------+-----+-------+-----+-----+ + * | dev | op | num of | byte0 | ... | byteN | crc | crc | + * | addr | code | bytes | | | | lsb | msb | + * +------+------+--------+-------+-----+-------+-----+-----+ + */ + char txbuf[SCD30_SERDEV_MAX_BUF_SIZE] = { SCD30_SERDEV_ADDR }, + rxbuf[SCD30_SERDEV_MAX_BUF_SIZE]; + int ret, rxsize, txsize = 2; + char *rsp = response; + u16 crc; + + put_unaligned_be16(scd30_serdev_cmd_lookup_tbl[cmd], txbuf + txsize); + txsize += 2; + + if (rsp) { + txbuf[1] = SCD30_SERDEV_READ; + if (cmd == CMD_READ_MEAS) + /* number of u16 words to read */ + put_unaligned_be16(size / 2, txbuf + txsize); + else + put_unaligned_be16(0x0001, txbuf + txsize); + txsize += 2; + crc = scd30_serdev_calc_crc(txbuf, txsize); + put_unaligned_le16(crc, txbuf + txsize); + txsize += 2; + rxsize = SCD30_SERDEV_RX_HEADER_SIZE + size + SCD30_SERDEV_CRC_SIZE; + } else { + if ((cmd == CMD_STOP_MEAS) || (cmd == CMD_RESET)) + arg = 0x0001; + + txbuf[1] = SCD30_SERDEV_WRITE; + put_unaligned_be16(arg, txbuf + txsize); + txsize += 2; + crc = scd30_serdev_calc_crc(txbuf, txsize); + put_unaligned_le16(crc, txbuf + txsize); + txsize += 2; + rxsize = txsize; + } + + ret = scd30_serdev_xfer(state, txbuf, txsize, rxbuf, rxsize); + if (ret) + return ret; + + switch (txbuf[1]) { + case SCD30_SERDEV_WRITE: + if (memcmp(txbuf, rxbuf, txsize)) { + dev_err(state->dev, "wrong message received\n"); + return -EIO; + } + break; + case SCD30_SERDEV_READ: + if (rxbuf[2] != (rxsize - SCD30_SERDEV_RX_HEADER_SIZE - SCD30_SERDEV_CRC_SIZE)) { + dev_err(state->dev, "received data size does not match header\n"); + return -EIO; + } + + rxsize -= SCD30_SERDEV_CRC_SIZE; + crc = get_unaligned_le16(rxbuf + rxsize); + if (crc != scd30_serdev_calc_crc(rxbuf, rxsize)) { + dev_err(state->dev, "data integrity check failed\n"); + return -EIO; + } + + rxsize -= SCD30_SERDEV_RX_HEADER_SIZE; + memcpy(rsp, rxbuf + SCD30_SERDEV_RX_HEADER_SIZE, rxsize); + break; + default: + dev_err(state->dev, "received unknown op code\n"); + return -EIO; + } + + return 0; +} + +static int scd30_serdev_receive_buf(struct serdev_device *serdev, + const unsigned char *buf, size_t size) +{ + struct iio_dev *indio_dev = dev_get_drvdata(&serdev->dev); + struct scd30_serdev_priv *priv; + struct scd30_state *state; + int num; + + if (!indio_dev) + return 0; + + state = iio_priv(indio_dev); + priv = state->priv; + + /* just in case sensor puts some unexpected bytes on the bus */ + if (!priv->buf) + return 0; + + if (priv->num + size >= priv->num_expected) + num = priv->num_expected - priv->num; + else + num = size; + + memcpy(priv->buf + priv->num, buf, num); + priv->num += num; + + if (priv->num == priv->num_expected) { + priv->buf = NULL; + complete(&priv->meas_ready); + } + + return num; +} + +static const struct serdev_device_ops scd30_serdev_ops = { + .receive_buf = scd30_serdev_receive_buf, + .write_wakeup = serdev_device_write_wakeup, +}; + +static int scd30_serdev_probe(struct serdev_device *serdev) +{ + struct device *dev = &serdev->dev; + struct scd30_serdev_priv *priv; + int irq, ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + init_completion(&priv->meas_ready); + serdev_device_set_client_ops(serdev, &scd30_serdev_ops); + + ret = devm_serdev_device_open(dev, serdev); + if (ret) + return ret; + + serdev_device_set_baudrate(serdev, 19200); + serdev_device_set_flow_control(serdev, false); + + ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE); + if (ret) + return ret; + + irq = fwnode_irq_get(dev_fwnode(dev), 0); + + return scd30_probe(dev, irq, KBUILD_MODNAME, priv, scd30_serdev_command); +} + +static const struct of_device_id scd30_serdev_of_match[] = { + { .compatible = "sensirion,scd30" }, + { } +}; +MODULE_DEVICE_TABLE(of, scd30_serdev_of_match); + +static struct serdev_device_driver scd30_serdev_driver = { + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = scd30_serdev_of_match, + .pm = &scd30_pm_ops, + }, + .probe = scd30_serdev_probe, +}; +module_serdev_device_driver(scd30_serdev_driver); + +MODULE_AUTHOR("Tomasz Duszynski <tomasz.duszynski@octakon.com>"); +MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor serial driver"); +MODULE_LICENSE("GPL v2");
Add serial interface driver for the SCD30 sensor. Signed-off-by: Tomasz Duszynski <tomasz.duszynski@octakon.com> --- MAINTAINERS | 1 + drivers/iio/chemical/Kconfig | 11 ++ drivers/iio/chemical/Makefile | 1 + drivers/iio/chemical/scd30_serial.c | 263 ++++++++++++++++++++++++++++ 4 files changed, 276 insertions(+) create mode 100644 drivers/iio/chemical/scd30_serial.c