| Message ID | 20200603084441.33952-3-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 I2C 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_i2c.c | 139 +++++++++++++++++++++++++++++++ > 4 files changed, 152 insertions(+) > create mode 100644 drivers/iio/chemical/scd30_i2c.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 41a509cca6f1..13aed3473b7e 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -15142,6 +15142,7 @@ M: Tomasz Duszynski <tomasz.duszynski@octakon.com> > S: Maintained > F: drivers/iio/chemical/scd30.h > F: drivers/iio/chemical/scd30_core.c > +F: drivers/iio/chemical/scd30_i2c.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 99e852b67e55..970d34888c2e 100644 > --- a/drivers/iio/chemical/Kconfig > +++ b/drivers/iio/chemical/Kconfig > @@ -96,6 +96,17 @@ config SCD30_CORE > To compile this driver as a module, choose M here: the module will > be called scd30_core. > > +config SCD30_I2C > + tristate "SCD30 carbon dioxide sensor I2C driver" > + depends on SCD30_CORE && I2C > + select CRC8 > + help > + Say Y here to build support for the Sensirion SCD30 I2C interface > + driver. > + > + To compile this driver as a module, choose M here: the module will > + be called scd30_i2c. > + > config SENSIRION_SGP30 > tristate "Sensirion SGPxx gas sensors" > depends on I2C > diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile > index c9804b041ecd..0966ca34e34b 100644 > --- a/drivers/iio/chemical/Makefile > +++ b/drivers/iio/chemical/Makefile > @@ -13,6 +13,7 @@ obj-$(CONFIG_CCS811) += ccs811.o > obj-$(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_SENSIRION_SGP30) += sgp30.o > obj-$(CONFIG_SPS30) += sps30.o > obj-$(CONFIG_VZ89X) += vz89x.o > diff --git a/drivers/iio/chemical/scd30_i2c.c b/drivers/iio/chemical/scd30_i2c.c > new file mode 100644 > index 000000000000..875892a070ee > --- /dev/null > +++ b/drivers/iio/chemical/scd30_i2c.c > @@ -0,0 +1,139 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Sensirion SCD30 carbon dioxide sensor i2c driver > + * > + * Copyright (c) 2020 Tomasz Duszynski <tomasz.duszynski@octakon.com> > + * > + * I2C slave address: 0x61 > + */ > +#include <linux/crc8.h> > +#include <linux/device.h> > +#include <linux/errno.h> > +#include <linux/i2c.h> > +#include <linux/mod_devicetable.h> > +#include <linux/module.h> > +#include <linux/types.h> > +#include <asm/unaligned.h> > + > +#include "scd30.h" > + > +#define SCD30_I2C_MAX_BUF_SIZE 18 > +#define SCD30_I2C_CRC8_POLYNOMIAL 0x31 > + > +static u16 scd30_i2c_cmd_lookup_tbl[] = { > + [CMD_START_MEAS] = 0x0010, > + [CMD_STOP_MEAS] = 0x0104, > + [CMD_MEAS_INTERVAL] = 0x4600, > + [CMD_MEAS_READY] = 0x0202, > + [CMD_READ_MEAS] = 0x0300, > + [CMD_ASC] = 0x5306, > + [CMD_FRC] = 0x5204, > + [CMD_TEMP_OFFSET] = 0x5403, > + [CMD_FW_VERSION] = 0xd100, > + [CMD_RESET] = 0xd304, > +}; > + > +DECLARE_CRC8_TABLE(scd30_i2c_crc8_tbl); > + > +static int scd30_i2c_xfer(struct scd30_state *state, char *txbuf, int txsize, > + char *rxbuf, int rxsize) > +{ > + struct i2c_client *client = to_i2c_client(state->dev); > + int ret; > + > + /* > + * repeated start is not supported hence instead of sending two i2c > + * messages in a row we send one by one > + */ > + ret = i2c_master_send(client, txbuf, txsize); > + if (ret < 0) > + return ret; > + if (ret != txsize) > + return -EIO; > + > + if (!rxbuf) > + return 0; > + > + ret = i2c_master_recv(client, rxbuf, rxsize); > + if (ret < 0) > + return ret; > + if (ret != rxsize) > + return -EIO; > + > + return 0; > +} > + > +static int scd30_i2c_command(struct scd30_state *state, enum scd30_cmd cmd, u16 arg, > + void *response, int size) > +{ > + char buf[SCD30_I2C_MAX_BUF_SIZE]; > + char *rsp = response; > + int i, ret; > + char crc; > + > + put_unaligned_be16(scd30_i2c_cmd_lookup_tbl[cmd], buf); > + i = 2; > + > + if (rsp) { > + /* each two bytes are followed by a crc8 */ > + size += size / 2; > + } else { > + put_unaligned_be16(arg, buf + i); > + crc = crc8(scd30_i2c_crc8_tbl, buf + i, 2, CRC8_INIT_VALUE); > + i += 2; > + buf[i] = crc; > + i += 1; > + > + /* commands below don't take an argument */ > + if ((cmd == CMD_STOP_MEAS) || (cmd == CMD_RESET)) > + i -= 3; > + } > + > + ret = scd30_i2c_xfer(state, buf, i, buf, size); > + if (ret) > + return ret; > + > + /* validate received data and strip off crc bytes */ > + for (i = 0; i < size; i += 3) { > + crc = crc8(scd30_i2c_crc8_tbl, buf + i, 2, CRC8_INIT_VALUE); > + if (crc != buf[i + 2]) { > + dev_err(state->dev, "data integrity check failed\n"); > + return -EIO; > + } > + > + *rsp++ = buf[i]; > + *rsp++ = buf[i + 1]; > + } > + > + return 0; > +} > + > +static int scd30_i2c_probe(struct i2c_client *client) > +{ > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) > + return -EOPNOTSUPP; > + > + crc8_populate_msb(scd30_i2c_crc8_tbl, SCD30_I2C_CRC8_POLYNOMIAL); > + > + return scd30_probe(&client->dev, client->irq, client->name, NULL, scd30_i2c_command); > +} > + > +static const struct of_device_id scd30_i2c_of_match[] = { > + { .compatible = "sensirion,scd30" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, scd30_i2c_of_match); > + > +static struct i2c_driver scd30_i2c_driver = { > + .driver = { > + .name = KBUILD_MODNAME, > + .of_match_table = scd30_i2c_of_match, > + .pm = &scd30_pm_ops, > + }, > + .probe_new = scd30_i2c_probe, > +}; > +module_i2c_driver(scd30_i2c_driver); > + > +MODULE_AUTHOR("Tomasz Duszynski <tomasz.duszynski@octakon.com>"); > +MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor i2c driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.27.0 >
diff --git a/MAINTAINERS b/MAINTAINERS index 41a509cca6f1..13aed3473b7e 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15142,6 +15142,7 @@ M: Tomasz Duszynski <tomasz.duszynski@octakon.com> S: Maintained F: drivers/iio/chemical/scd30.h F: drivers/iio/chemical/scd30_core.c +F: drivers/iio/chemical/scd30_i2c.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 99e852b67e55..970d34888c2e 100644 --- a/drivers/iio/chemical/Kconfig +++ b/drivers/iio/chemical/Kconfig @@ -96,6 +96,17 @@ config SCD30_CORE To compile this driver as a module, choose M here: the module will be called scd30_core. +config SCD30_I2C + tristate "SCD30 carbon dioxide sensor I2C driver" + depends on SCD30_CORE && I2C + select CRC8 + help + Say Y here to build support for the Sensirion SCD30 I2C interface + driver. + + To compile this driver as a module, choose M here: the module will + be called scd30_i2c. + config SENSIRION_SGP30 tristate "Sensirion SGPxx gas sensors" depends on I2C diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile index c9804b041ecd..0966ca34e34b 100644 --- a/drivers/iio/chemical/Makefile +++ b/drivers/iio/chemical/Makefile @@ -13,6 +13,7 @@ obj-$(CONFIG_CCS811) += ccs811.o obj-$(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_SENSIRION_SGP30) += sgp30.o obj-$(CONFIG_SPS30) += sps30.o obj-$(CONFIG_VZ89X) += vz89x.o diff --git a/drivers/iio/chemical/scd30_i2c.c b/drivers/iio/chemical/scd30_i2c.c new file mode 100644 index 000000000000..875892a070ee --- /dev/null +++ b/drivers/iio/chemical/scd30_i2c.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Sensirion SCD30 carbon dioxide sensor i2c driver + * + * Copyright (c) 2020 Tomasz Duszynski <tomasz.duszynski@octakon.com> + * + * I2C slave address: 0x61 + */ +#include <linux/crc8.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/i2c.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/types.h> +#include <asm/unaligned.h> + +#include "scd30.h" + +#define SCD30_I2C_MAX_BUF_SIZE 18 +#define SCD30_I2C_CRC8_POLYNOMIAL 0x31 + +static u16 scd30_i2c_cmd_lookup_tbl[] = { + [CMD_START_MEAS] = 0x0010, + [CMD_STOP_MEAS] = 0x0104, + [CMD_MEAS_INTERVAL] = 0x4600, + [CMD_MEAS_READY] = 0x0202, + [CMD_READ_MEAS] = 0x0300, + [CMD_ASC] = 0x5306, + [CMD_FRC] = 0x5204, + [CMD_TEMP_OFFSET] = 0x5403, + [CMD_FW_VERSION] = 0xd100, + [CMD_RESET] = 0xd304, +}; + +DECLARE_CRC8_TABLE(scd30_i2c_crc8_tbl); + +static int scd30_i2c_xfer(struct scd30_state *state, char *txbuf, int txsize, + char *rxbuf, int rxsize) +{ + struct i2c_client *client = to_i2c_client(state->dev); + int ret; + + /* + * repeated start is not supported hence instead of sending two i2c + * messages in a row we send one by one + */ + ret = i2c_master_send(client, txbuf, txsize); + if (ret < 0) + return ret; + if (ret != txsize) + return -EIO; + + if (!rxbuf) + return 0; + + ret = i2c_master_recv(client, rxbuf, rxsize); + if (ret < 0) + return ret; + if (ret != rxsize) + return -EIO; + + return 0; +} + +static int scd30_i2c_command(struct scd30_state *state, enum scd30_cmd cmd, u16 arg, + void *response, int size) +{ + char buf[SCD30_I2C_MAX_BUF_SIZE]; + char *rsp = response; + int i, ret; + char crc; + + put_unaligned_be16(scd30_i2c_cmd_lookup_tbl[cmd], buf); + i = 2; + + if (rsp) { + /* each two bytes are followed by a crc8 */ + size += size / 2; + } else { + put_unaligned_be16(arg, buf + i); + crc = crc8(scd30_i2c_crc8_tbl, buf + i, 2, CRC8_INIT_VALUE); + i += 2; + buf[i] = crc; + i += 1; + + /* commands below don't take an argument */ + if ((cmd == CMD_STOP_MEAS) || (cmd == CMD_RESET)) + i -= 3; + } + + ret = scd30_i2c_xfer(state, buf, i, buf, size); + if (ret) + return ret; + + /* validate received data and strip off crc bytes */ + for (i = 0; i < size; i += 3) { + crc = crc8(scd30_i2c_crc8_tbl, buf + i, 2, CRC8_INIT_VALUE); + if (crc != buf[i + 2]) { + dev_err(state->dev, "data integrity check failed\n"); + return -EIO; + } + + *rsp++ = buf[i]; + *rsp++ = buf[i + 1]; + } + + return 0; +} + +static int scd30_i2c_probe(struct i2c_client *client) +{ + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return -EOPNOTSUPP; + + crc8_populate_msb(scd30_i2c_crc8_tbl, SCD30_I2C_CRC8_POLYNOMIAL); + + return scd30_probe(&client->dev, client->irq, client->name, NULL, scd30_i2c_command); +} + +static const struct of_device_id scd30_i2c_of_match[] = { + { .compatible = "sensirion,scd30" }, + { } +}; +MODULE_DEVICE_TABLE(of, scd30_i2c_of_match); + +static struct i2c_driver scd30_i2c_driver = { + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = scd30_i2c_of_match, + .pm = &scd30_pm_ops, + }, + .probe_new = scd30_i2c_probe, +}; +module_i2c_driver(scd30_i2c_driver); + +MODULE_AUTHOR("Tomasz Duszynski <tomasz.duszynski@octakon.com>"); +MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor i2c driver"); +MODULE_LICENSE("GPL v2");
Add I2C 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_i2c.c | 139 +++++++++++++++++++++++++++++++ 4 files changed, 152 insertions(+) create mode 100644 drivers/iio/chemical/scd30_i2c.c