Add I2C interface driver for the SCD30 sensor.
Signed-off-by: Tomasz Duszynski <[email protected]>
---
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 <[email protected]>
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 <[email protected]>
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 <[email protected]>
+ *
+ * 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 <[email protected]>");
+MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor i2c driver");
+MODULE_LICENSE("GPL v2");
--
2.27.0
On Wed, Jun 3, 2020 at 11:47 AM Tomasz Duszynski
<[email protected]> wrote:
>
> Add I2C interface driver for the SCD30 sensor.
>
FWIW,
Reviewed-by: Andy Shevchenko <[email protected]>
> Signed-off-by: Tomasz Duszynski <[email protected]>
> ---
> 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 <[email protected]>
> 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 <[email protected]>
> 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 <[email protected]>
> + *
> + * 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 <[email protected]>");
> +MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor i2c driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.27.0
>
--
With Best Regards,
Andy Shevchenko