[PATCH v4 0/3] iio: chemical: Add Senseair Sunrise CO2 sensor

[PATCH v4 0/3] iio: chemical: Add Senseair Sunrise CO2 sensor

[Jacopo Mondi]

The driver supports continuous reads of temperature and CO2 concentration
through two dedicated IIO channels. It also supports calibration and error
inspection through the concentration channel ext_info.

A few substantial changes in v4, mostly in the calibration attributes
definition but also in the driver code

v3->v4
 - Rebased on v5.14
 - Remove unneeded Kconfig symbol dependencies
 - Remove unused header inclusion
 - Lock access to calibration and error status
 - Fix temperature scale
 - Fix for_each_set_bit()
 - Drop a few fields from driver's main structure
 - Lock the 'wakeup' session with an additional mutex
 - Disable regmap locking as the access to the i2c bus is now externally locked
 - Rework the calibration attributes defintion: one attribute per calibration
   mode
 - Make 'error_status' attributes SHARED_BY_ALL
 - Replace regmap_read_poll_timeout() with read_poll_timeout() to use
   the driver's byte read function that performs the proper chip 'wakeup'.
   It used to work with the previous version too, a few spurious NAK apart but
   this seems cleaner and allows to relax the sleep time
 - Update ABI documentation according to the new attributes layout
 - Remove label from bindings doc

v2->v3:
- [1/3]
 - Fix syntax error reported by dt_binding_check
   The device node label in the example cannot contain '-'
 - Add 'Typically' to the gpios polarities description

- [2/3]
 - As suggested by Andy:
   - depends on OF, SYSFS; select REGMAP_I2C
   - Fix style issues:
     - span over 80 cols where appropriate
     - remove , in last entries of all arrays
     - use for_each_set_bit in sunrise_error_status_read()
     - minor style issues (brakets, empty lines, wording)

v1->v2:
- Add ABI documentation in [3/3]
- [1/3]
  - Address Rob's comments on missing maxItem and add device node label
  - Do not change the pin's polarity description as suggested by Andy due to
    conflicting suggestions
- [2/3]
  - Expand Kconfig symbol name and change driver's name as suggested by Andy
  - Use regmap instead of raw smbus calls as suggested by Andy
  - Take into account minor style comments from Andy
  - Install channel's ext_info to support calibration triggering and enumerate
    calibration modes and error status
  - Matt suggested to use sysfs attributes, but I found the per-channel
    attributes more appropriate. Hope this is good as well.


Jacopo Mondi (3):
  dt-bindings: iio: chemical: Document senseair,sunrise CO2 sensor
  iio: chemical: Add Senseair Sunrise 006-0-007 driver
  iio: ABI: docs: Document Senseair Sunrise ABI

 .../sysfs-bus-iio-chemical-sunrise-co2        |  38 ++
 .../iio/chemical/senseair,sunrise.yaml        |  55 +++
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 MAINTAINERS                                   |   6 +
 drivers/iio/chemical/Kconfig                  |  10 +
 drivers/iio/chemical/Makefile                 |   1 +
 drivers/iio/chemical/sunrise_co2.c            | 462 ++++++++++++++++++
 7 files changed, 574 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2
 create mode 100644 Documentation/devicetree/bindings/iio/chemical/senseair,sunrise.yaml
 create mode 100644 drivers/iio/chemical/sunrise_co2.c

--
2.32.0

[PATCH v4 1/3] dt-bindings: iio: chemical: Document senseair,sunrise CO2 sensor

[Jacopo Mondi]

Add documentation for the Senseair Sunrise 006-0-0007 CO2 NDIR sensor.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../iio/chemical/senseair,sunrise.yaml        | 55 +++++++++++++++++++
 .../devicetree/bindings/vendor-prefixes.yaml  |  2 +
 2 files changed, 57 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/chemical/senseair,sunrise.yaml

diff --git a/Documentation/devicetree/bindings/iio/chemical/senseair,sunrise.yaml b/Documentation/devicetree/bindings/iio/chemical/senseair,sunrise.yaml
new file mode 100644
index 000000000000..337fe09e4bb8
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/chemical/senseair,sunrise.yaml
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/chemical/senseair,sunrise.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Senseair Sunrise 006-0-0007 CO2 Sensor
+
+maintainers:
+  - Jacopo Mondi <jacopo@jmondi.org>
+
+description: |
+  Senseair Sunrise 006-0-0007 is a NDIR CO2 sensor. It supports I2C or UART buses
+  for communications and control.
+
+  Datasheets:
+    https://rmtplusstoragesenseair.blob.core.windows.net/docs/Dev/publicerat/PSP11704.pdf
+    https://rmtplusstoragesenseair.blob.core.windows.net/docs/Dev/publicerat/PSH11649.pdf
+    https://rmtplusstoragesenseair.blob.core.windows.net/docs/Dev/publicerat/TDE5531.pdf
+    https://rmtplusstoragesenseair.blob.core.windows.net/docs/Market/publicerat/TDE7318.pdf
+
+properties:
+  compatible:
+    const: senseair,sunrise-006-0-0007
+
+  reg:
+    maxItems: 1
+
+  ndry-gpios:
+    maxItems: 1
+    description:
+      Phandle to the GPIO line connected to the nDRY pin. Typically active low.
+
+  en-gpios:
+    maxItems: 1
+    description:
+      Phandle to the GPIO line connected to the EN pin. Typically active high.
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      co2-sensor@68 {
+        compatible = "senseair,sunrise-006-0-0007";
+        reg = <0x68>;
+      };
+    };
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index 07fb0d25fc15..8415e6067ce1 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -1008,6 +1008,8 @@ patternProperties:
     description: Shenzhen SEI Robotics Co., Ltd
   "^semtech,.*":
     description: Semtech Corporation
+  "^senseair,.*":
+    description: Senseair AB
   "^sensirion,.*":
     description: Sensirion AG
   "^sensortek,.*":
-- 
2.32.0

[PATCH v4 2/3] iio: chemical: Add Senseair Sunrise 006-0-007 driver

[Jacopo Mondi]

Add support for the Senseair Sunrise 006-0-0007 driver through the
IIO subsystem.

Datasheet: https://rmtplusstoragesenseair.blob.core.windows.net/docs/Dev/publicerat/TDE5531.pdf
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
---
 MAINTAINERS                        |   6 +
 drivers/iio/chemical/Kconfig       |  10 +
 drivers/iio/chemical/Makefile      |   1 +
 drivers/iio/chemical/sunrise_co2.c | 487 +++++++++++++++++++++++++++++
 4 files changed, 504 insertions(+)
 create mode 100644 drivers/iio/chemical/sunrise_co2.c

diff --git a/MAINTAINERS b/MAINTAINERS
index d7b4f32875a9..a8b859297e9e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16723,6 +16723,12 @@ S:	Maintained
 F:	drivers/misc/phantom.c
 F:	include/uapi/linux/phantom.h

+SENSEAIR SUNRISE 006-0-0007
+M:	Jacopo Mondi <jacopo@jmondi.org>
+S:	Maintained
+F:	Documentation/devicetree/bindings/iio/chemical/senseair,sunrise.yaml
+F:	drivers/iio/chemical/sunrise_co2.c
+
 SENSIRION SCD30 CARBON DIOXIDE SENSOR DRIVER
 M:	Tomasz Duszynski <tomasz.duszynski@octakon.com>
 S:	Maintained
diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
index a4920646e9be..5155ab2caed4 100644
--- a/drivers/iio/chemical/Kconfig
+++ b/drivers/iio/chemical/Kconfig
@@ -159,6 +159,16 @@ config SPS30_SERIAL
 	  To compile this driver as a module, choose M here: the module will
 	  be called sps30_serial.

+config SENSEAIR_SUNRISE_CO2
+	tristate "Senseair Sunrise 006-0-0007 CO2 sensor"
+	select REGMAP_I2C
+	help
+	  Say yes here to build support for Senseair Sunrise 006-0-0007 CO2
+	  sensor.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called sunrise_co2.
+
 config VZ89X
 	tristate "SGX Sensortech MiCS VZ89X VOC sensor"
 	depends on I2C
diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
index 4898690cc155..61e8749a84f3 100644
--- a/drivers/iio/chemical/Makefile
+++ b/drivers/iio/chemical/Makefile
@@ -15,6 +15,7 @@ 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-$(CONFIG_SENSEAIR_SUNRISE_CO2) += sunrise_co2.o
 obj-$(CONFIG_SENSIRION_SGP30)	+= sgp30.o
 obj-$(CONFIG_SPS30) += sps30.o
 obj-$(CONFIG_SPS30_I2C) += sps30_i2c.o
diff --git a/drivers/iio/chemical/sunrise_co2.c b/drivers/iio/chemical/sunrise_co2.c
new file mode 100644
index 000000000000..cf15cdbaa24a
--- /dev/null
+++ b/drivers/iio/chemical/sunrise_co2.c
@@ -0,0 +1,487 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Senseair Sunrise 006-0-0007 CO2 sensor driver.
+ *
+ * Copyright (C) 2021 Jacopo Mondi
+ *
+ * List of features not yet supported by the driver:
+ * - controllable EN pin
+ * - single-shot operations using the nDRY pin.
+ * - ABC/target calibration
+ */
+
+#include <linux/bitops.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/time64.h>
+
+#include <linux/iio/iio.h>
+
+#define DRIVER_NAME "sunrise_co2"
+
+#define SUNRISE_ERROR_STATUS_REG		0x00
+#define SUNRISE_CO2_FILTERED_COMP_REG		0x06
+#define SUNRISE_CHIP_TEMPERATURE_REG		0x08
+#define SUNRISE_CALIBRATION_STATUS_REG		0x81
+#define SUNRISE_CALIBRATION_COMMAND_REG		0x82
+#define SUNRISE_CALIBRATION_FACTORY_CMD		0x7c02
+#define SUNRISE_CALIBRATION_BACKGROUND_CMD	0x7c06
+/*
+ * The calibration timeout is not characterized in the datasheet.
+ * Use 30 seconds as a reasonable upper limit.
+ */
+#define SUNRISE_CALIBRATION_TIMEOUT_US		(30 * USEC_PER_SEC)
+
+struct sunrise_dev {
+	struct i2c_client *client;
+	struct regmap *regmap;
+	/* Protects access to IIO attributes. */
+	struct mutex lock;
+	/* Protects chip's wakup session. */
+	struct mutex wakeup_lock;
+};
+
+static void sunrise_wakeup(struct sunrise_dev *sunrise)
+{
+	struct i2c_client *client = sunrise->client;
+
+	/*
+	 * Wake up sensor by sending sensor address: START, sensor address,
+	 * STOP. Sensor will not ACK this byte.
+	 *
+	 * The chip returns in low power state after 15msec without
+	 * communications or after a complete read/write sequence.
+	 */
+	i2c_smbus_xfer(client->adapter, client->addr, I2C_M_IGNORE_NAK,
+		       I2C_SMBUS_WRITE, 0, I2C_SMBUS_QUICK, NULL);
+}
+
+static int sunrise_read_byte(struct sunrise_dev *sunrise, u8 reg)
+{
+	unsigned int val;
+	int ret;
+
+	/*
+	 * Lock the 'wakeup' session.
+	 *
+	 * If another read/write call sneaks in between the wakeup message
+	 * and the i2c transaction, the chip goes back in sleep state.
+	 */
+	mutex_lock(&sunrise->wakeup_lock);
+	sunrise_wakeup(sunrise);
+	ret = regmap_read(sunrise->regmap, reg, &val);
+	mutex_unlock(&sunrise->wakeup_lock);
+	if (ret) {
+		dev_err(&sunrise->client->dev,
+			"Read byte failed: reg 0x%2x (%d)\n", reg, ret);
+		return ret;
+	}
+
+	return val;
+}
+
+static int sunrise_read_word(struct sunrise_dev *sunrise, u8 reg, u16 *val)
+{
+	__be16 be_val;
+	int ret;
+
+	mutex_lock(&sunrise->wakeup_lock);
+	sunrise_wakeup(sunrise);
+	ret = regmap_bulk_read(sunrise->regmap, reg, &be_val, 2);
+	mutex_unlock(&sunrise->wakeup_lock);
+	if (ret) {
+		dev_err(&sunrise->client->dev,
+			"Read word failed: reg 0x%2x (%d)\n", reg, ret);
+		return ret;
+	}
+
+	*val = be16_to_cpu(be_val);
+
+	return 0;
+}
+
+static int sunrise_write_byte(struct sunrise_dev *sunrise, u8 reg, u8 val)
+{
+	int ret;
+
+	mutex_lock(&sunrise->wakeup_lock);
+	sunrise_wakeup(sunrise);
+	ret = regmap_write(sunrise->regmap, reg, val);
+	mutex_unlock(&sunrise->wakeup_lock);
+	if (ret) {
+		dev_err(&sunrise->client->dev,
+			"Write byte failed: reg 0x%2x (%d)\n", reg, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data)
+{
+	__be16 be_data = cpu_to_be16(data);
+	int ret;
+
+	mutex_lock(&sunrise->wakeup_lock);
+	sunrise_wakeup(sunrise);
+	ret = regmap_bulk_write(sunrise->regmap, reg, &be_data, 2);
+	mutex_unlock(&sunrise->wakeup_lock);
+	if (ret) {
+		dev_err(&sunrise->client->dev,
+			"Write word failed: reg 0x%2x (%d)\n", reg, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+/* Trigger a calibration cycle. */
+
+enum {
+	SUNRISE_CALIBRATION_FACTORY,
+	SUNRISE_CALIBRATION_BACKGROUND,
+};
+
+static const struct sunrise_calib_data {
+	u16 cmd;
+	u8 bit;
+	const char * const name;
+} calib_data[] = {
+	[SUNRISE_CALIBRATION_FACTORY] = {
+		SUNRISE_CALIBRATION_FACTORY_CMD,
+		BIT(2),
+		"factory_calibration",
+	},
+	[SUNRISE_CALIBRATION_BACKGROUND] = {
+		SUNRISE_CALIBRATION_BACKGROUND_CMD,
+		BIT(5),
+		"background_calibration",
+	},
+};
+
+static int sunrise_calibrate(struct sunrise_dev *sunrise,
+			     const struct sunrise_calib_data *data)
+{
+	unsigned int status;
+	int ret;
+
+	/* Reset the calibration status reg. */
+	ret = sunrise_write_byte(sunrise, SUNRISE_CALIBRATION_STATUS_REG, 0x00);
+	if (ret)
+		return ret;
+
+	/* Write a calibration command and poll the calibration status bit. */
+	ret = sunrise_write_word(sunrise, SUNRISE_CALIBRATION_COMMAND_REG,
+				 data->cmd);
+	if (ret)
+		return ret;
+
+	dev_dbg(&sunrise->client->dev, "%s in progress\n", data->name);
+
+	/*
+	 * Calibration takes several seconds, so the sleep time between reads
+	 * can be pretty relaxed.
+	 */
+	return read_poll_timeout(sunrise_read_byte, status,
+				 status & data->bit, 200000,
+				 SUNRISE_CALIBRATION_TIMEOUT_US, false,
+				 sunrise, SUNRISE_CALIBRATION_STATUS_REG);
+}
+
+static ssize_t sunrise_cal_read(const char *buf, size_t len)
+{
+	bool enable;
+	int ret;
+
+	ret = kstrtobool(buf, &enable);
+	if (ret)
+		return ret;
+
+	if (!enable)
+		return len;
+
+	return 0;
+}
+
+static ssize_t sunrise_cal_factory_write(struct iio_dev *iiodev,
+					 uintptr_t private,
+					 const struct iio_chan_spec *chan,
+					 const char *buf, size_t len)
+{
+	struct sunrise_dev *sunrise = iio_priv(iiodev);
+	int ret;
+
+	mutex_lock(&sunrise->lock);
+	ret = sunrise_cal_read(buf, len);
+	if (ret) {
+		mutex_unlock(&sunrise->lock);
+		return ret;
+	}
+
+	ret = sunrise_calibrate(sunrise,
+				&calib_data[SUNRISE_CALIBRATION_FACTORY]);
+	mutex_unlock(&sunrise->lock);
+	if (ret)
+		return ret;
+
+	return len;
+}
+
+static ssize_t sunrise_cal_background_write(struct iio_dev *iiodev,
+					    uintptr_t private,
+					    const struct iio_chan_spec *chan,
+					    const char *buf, size_t len)
+{
+	struct sunrise_dev *sunrise = iio_priv(iiodev);
+	int ret;
+
+	mutex_lock(&sunrise->lock);
+	ret = sunrise_cal_read(buf, len);
+	if (ret) {
+		mutex_unlock(&sunrise->lock);
+		return ret;
+	}
+
+	ret = sunrise_calibrate(sunrise,
+				&calib_data[SUNRISE_CALIBRATION_BACKGROUND]);
+	mutex_unlock(&sunrise->lock);
+	if (ret)
+		return ret;
+
+	return len;
+}
+
+ /* Enumerate and retrieve the chip error status. */
+enum {
+	SUNRISE_ERROR_FATAL,
+	SUNRISE_ERROR_I2C,
+	SUNRISE_ERROR_ALGORITHM,
+	SUNRISE_ERROR_CALIBRATION,
+	SUNRISE_ERROR_SELF_DIAGNOSTIC,
+	SUNRISE_ERROR_OUT_OF_RANGE,
+	SUNRISE_ERROR_MEMORY,
+	SUNRISE_ERROR_NO_MEASUREMENT,
+	SUNRISE_ERROR_LOW_VOLTAGE,
+	SUNRISE_ERROR_MEASUREMENT_TIMEOUT,
+};
+
+static const char * const sunrise_error_statuses[] = {
+	[SUNRISE_ERROR_FATAL] = "error_fatal",
+	[SUNRISE_ERROR_I2C] = "error_i2c",
+	[SUNRISE_ERROR_ALGORITHM] = "error_algorithm",
+	[SUNRISE_ERROR_CALIBRATION] = "error_calibration",
+	[SUNRISE_ERROR_SELF_DIAGNOSTIC] = "error_self_diagnostic",
+	[SUNRISE_ERROR_OUT_OF_RANGE] = "error_out_of_range",
+	[SUNRISE_ERROR_MEMORY] = "error_memory",
+	[SUNRISE_ERROR_NO_MEASUREMENT] = "error_no_measurement",
+	[SUNRISE_ERROR_LOW_VOLTAGE] = "error_low_voltage",
+	[SUNRISE_ERROR_MEASUREMENT_TIMEOUT] = "error_measurement_timeout",
+};
+
+static const struct iio_enum sunrise_error_statuses_enum = {
+	.items = sunrise_error_statuses,
+	.num_items = ARRAY_SIZE(sunrise_error_statuses),
+};
+
+static ssize_t sunrise_error_status_read(struct iio_dev *iiodev,
+					 uintptr_t private,
+					 const struct iio_chan_spec *chan,
+					 char *buf)
+{
+	struct sunrise_dev *sunrise = iio_priv(iiodev);
+	unsigned long errors;
+	ssize_t len = 0;
+	u16 value;
+	int ret;
+	u8 i;
+
+	mutex_lock(&sunrise->lock);
+	ret = sunrise_read_word(sunrise, SUNRISE_ERROR_STATUS_REG, &value);
+	if (ret) {
+		mutex_unlock(&sunrise->lock);
+		return -EINVAL;
+	}
+
+	errors = value;
+	for_each_set_bit(i, &errors, ARRAY_SIZE(sunrise_error_statuses))
+		len += sysfs_emit_at(buf, len, "%s ", sunrise_error_statuses[i]);
+
+	if (len)
+		buf[len - 1] = '\n';
+
+	mutex_unlock(&sunrise->lock);
+
+	return len;
+}
+
+static const struct iio_chan_spec_ext_info sunrise_concentration_ext_info[] = {
+	/* Calibration triggers. */
+	{
+		.name = "calibration_factory",
+		.write = sunrise_cal_factory_write,
+		.shared = IIO_SEPARATE,
+	},
+	{
+		.name = "calibration_background",
+		.write = sunrise_cal_background_write,
+		.shared = IIO_SEPARATE,
+	},
+
+	/* Error statuses. */
+	{
+		.name = "error_status",
+		.read = sunrise_error_status_read,
+		.shared = IIO_SHARED_BY_ALL,
+	},
+	{
+		.name = "error_status_available",
+		.shared = IIO_SHARED_BY_ALL,
+		.read = iio_enum_available_read,
+		.private = (uintptr_t)&sunrise_error_statuses_enum,
+	},
+	{}
+};
+
+static const struct iio_chan_spec sunrise_channels[] = {
+	{
+		.type = IIO_CONCENTRATION,
+		.modified = 1,
+		.channel2 = IIO_MOD_CO2,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.ext_info = sunrise_concentration_ext_info,
+		.scan_index = 0,
+		.scan_type =  {
+			.sign = 's',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_CPU,
+		},
+	},
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate =  BIT(IIO_CHAN_INFO_RAW) |
+				       BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = 1,
+		.scan_type =  {
+			.sign = 's',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_CPU,
+		},
+	},
+};
+
+static int sunrise_read_raw(struct iio_dev *iio_dev,
+			    const struct iio_chan_spec *chan,
+			    int *val, int *val2, long mask)
+{
+	struct sunrise_dev *sunrise = iio_priv(iio_dev);
+	u16 value;
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_CONCENTRATION:
+			mutex_lock(&sunrise->lock);
+			ret = sunrise_read_word(sunrise, SUNRISE_CO2_FILTERED_COMP_REG,
+						&value);
+			*val = value;
+			mutex_unlock(&sunrise->lock);
+
+			if (ret)
+				return ret;
+
+			return IIO_VAL_INT;
+
+		case IIO_TEMP:
+			mutex_lock(&sunrise->lock);
+			ret = sunrise_read_word(sunrise, SUNRISE_CHIP_TEMPERATURE_REG,
+						&value);
+			*val = value;
+			mutex_unlock(&sunrise->lock);
+
+			if (ret)
+				return ret;
+
+			return IIO_VAL_INT;
+
+		default:
+			return -EINVAL;
+		}
+
+	case IIO_CHAN_INFO_SCALE:
+		/* x10 to comply with IIO scale (1/1000 degress celsius). */
+		*val = 10;
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info sunrise_info = {
+	.read_raw = sunrise_read_raw,
+};
+
+static struct regmap_config sunrise_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	/*
+	 * Access to the i2c bus is locked by the driver to preserve the
+	 * 'wakeup' session.
+	 */
+	.disable_locking = true,
+};
+
+static int sunrise_probe(struct i2c_client *client)
+{
+	struct sunrise_dev *sunrise;
+	struct iio_dev *iio_dev;
+
+	iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*sunrise));
+	if (!iio_dev)
+		return -ENOMEM;
+
+	sunrise = iio_priv(iio_dev);
+	sunrise->client = client;
+	mutex_init(&sunrise->lock);
+	mutex_init(&sunrise->wakeup_lock);
+
+	sunrise->regmap = devm_regmap_init_i2c(client, &sunrise_regmap_config);
+	if (IS_ERR(sunrise->regmap)) {
+		dev_err(&client->dev, "Failed to initialize regmap\n");
+		return PTR_ERR(sunrise->regmap);
+	}
+
+	iio_dev->info = &sunrise_info;
+	iio_dev->name = DRIVER_NAME;
+	iio_dev->channels = sunrise_channels;
+	iio_dev->num_channels = ARRAY_SIZE(sunrise_channels);
+	iio_dev->modes = INDIO_DIRECT_MODE;
+
+	return devm_iio_device_register(&client->dev, iio_dev);
+}
+
+static const struct of_device_id sunrise_of_match[] = {
+	{ .compatible = "senseair,sunrise-006-0-0007" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sunrise_of_match);
+
+static struct i2c_driver sunrise_driver = {
+	.driver = {
+		.name = DRIVER_NAME,
+		.of_match_table = sunrise_of_match,
+	},
+	.probe_new = sunrise_probe,
+};
+module_i2c_driver(sunrise_driver);
+
+MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>");
+MODULE_DESCRIPTION("Senseair Sunrise 006-0-0007 CO2 sensor IIO driver");
+MODULE_LICENSE("GPL v2");
--
2.32.0

Re: [PATCH v4 2/3] iio: chemical: Add Senseair Sunrise 006-0-007 driver

[Andy Shevchenko]

On Fri, Sep 3, 2021 at 5:50 PM Jacopo Mondi <jacopo@jmondi.org> wrote:
>
> Add support for the Senseair Sunrise 006-0-0007 driver through the
> IIO subsystem.

...

> +static int sunrise_read_byte(struct sunrise_dev *sunrise, u8 reg)
> +{
> +       unsigned int val;
> +       int ret;
> +
> +       /*
> +        * Lock the 'wakeup' session.
> +        *
> +        * If another read/write call sneaks in between the wakeup message
> +        * and the i2c transaction, the chip goes back in sleep state.
> +        */

> +       mutex_lock(&sunrise->wakeup_lock);
> +       sunrise_wakeup(sunrise);
> +       ret = regmap_read(sunrise->regmap, reg, &val);
> +       mutex_unlock(&sunrise->wakeup_lock);

Seems to me that you may redefine ->read() for regmap (but double
check this, esp. in regard to bulk transfers) with wakeup implied and
in that case you probably can use regmap's lock only.

> +       if (ret) {

> +               dev_err(&sunrise->client->dev,
> +                       "Read byte failed: reg 0x%2x (%d)\n", reg, ret);

With the same LOCs I slightly prefer temporary variable

struct device *dev = ...;
  ...
dev_err(dev, ...); // on a single line

Ditto everywhere.

> +               return ret;
> +       }
> +
> +       return val;
> +}

...

> +static int sunrise_read_word(struct sunrise_dev *sunrise, u8 reg, u16 *val)
> +{
> +       __be16 be_val;
> +       int ret;
> +
> +       mutex_lock(&sunrise->wakeup_lock);
> +       sunrise_wakeup(sunrise);

> +       ret = regmap_bulk_read(sunrise->regmap, reg, &be_val, 2);

sizeof(be_val)

> +       mutex_unlock(&sunrise->wakeup_lock);
> +       if (ret) {
> +               dev_err(&sunrise->client->dev,
> +                       "Read word failed: reg 0x%2x (%d)\n", reg, ret);
> +               return ret;
> +       }
> +
> +       *val = be16_to_cpu(be_val);
> +
> +       return 0;
> +}

...

> +static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data)
> +{
> +       __be16 be_data = cpu_to_be16(data);
> +       int ret;
> +
> +       mutex_lock(&sunrise->wakeup_lock);
> +       sunrise_wakeup(sunrise);
> +       ret = regmap_bulk_write(sunrise->regmap, reg, &be_data, 2);
> +       mutex_unlock(&sunrise->wakeup_lock);
> +       if (ret) {
> +               dev_err(&sunrise->client->dev,
> +                       "Write word failed: reg 0x%2x (%d)\n", reg, ret);

> +               return ret;
> +       }
> +
> +       return 0;

return ret;

> +}

...

> +       /* Write a calibration command and poll the calibration status bit. */
> +       ret = sunrise_write_word(sunrise, SUNRISE_CALIBRATION_COMMAND_REG,
> +                                data->cmd);

Dunno how long it is, but to me seems one line is okay.

> +       if (ret)
> +               return ret;

...

> +static ssize_t sunrise_cal_read(const char *buf, size_t len)
> +{
> +       bool enable;
> +       int ret;
> +
> +       ret = kstrtobool(buf, &enable);
> +       if (ret)
> +               return ret;
> +
> +       if (!enable)
> +               return len;
> +
> +       return 0;

Why is this a separate function to begin with?

Not sure I have got the logic behind. If enable is true you return 0?!

> +}

...

> +static ssize_t sunrise_cal_factory_write(struct iio_dev *iiodev,
> +                                        uintptr_t private,
> +                                        const struct iio_chan_spec *chan,
> +                                        const char *buf, size_t len)
> +{
> +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> +       int ret;
> +
> +       mutex_lock(&sunrise->lock);
> +       ret = sunrise_cal_read(buf, len);

> +       if (ret) {
> +               mutex_unlock(&sunrise->lock);
> +               return ret;
> +       }

Possibly

  if (ret)
    goto out_unlock;

> +       ret = sunrise_calibrate(sunrise,
> +                               &calib_data[SUNRISE_CALIBRATION_FACTORY]);

One line?

out_unlock:

> +       mutex_unlock(&sunrise->lock);
> +       if (ret)
> +               return ret;
> +
> +       return len;
> +}

...

> +       errors = value;
> +       for_each_set_bit(i, &errors, ARRAY_SIZE(sunrise_error_statuses))
> +               len += sysfs_emit_at(buf, len, "%s ", sunrise_error_statuses[i]);

> +

Can drop this (up to you).

> +       if (len)
> +               buf[len - 1] = '\n';

...

> +                       ret = sunrise_read_word(sunrise, SUNRISE_CO2_FILTERED_COMP_REG,
> +                                               &value);

One line?

...

> +                       ret = sunrise_read_word(sunrise, SUNRISE_CHIP_TEMPERATURE_REG,
> +                                               &value);

Ditto.

...

> +               /* x10 to comply with IIO scale (1/1000 degress celsius). */

1/1000 -->  millidegrees
(Also note spelling)

--
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 2/3] iio: chemical: Add Senseair Sunrise 006-0-007 driver

[Jacopo Mondi]

Hi Andy,

On Fri, Sep 03, 2021 at 06:36:44PM +0300, Andy Shevchenko wrote:
> On Fri, Sep 3, 2021 at 5:50 PM Jacopo Mondi <jacopo@jmondi.org> wrote:
> >
> > Add support for the Senseair Sunrise 006-0-0007 driver through the
> > IIO subsystem.
>
> ...
>
> > +static int sunrise_read_byte(struct sunrise_dev *sunrise, u8 reg)
> > +{
> > +       unsigned int val;
> > +       int ret;
> > +
> > +       /*
> > +        * Lock the 'wakeup' session.
> > +        *
> > +        * If another read/write call sneaks in between the wakeup message
> > +        * and the i2c transaction, the chip goes back in sleep state.
> > +        */
>
> > +       mutex_lock(&sunrise->wakeup_lock);
> > +       sunrise_wakeup(sunrise);
> > +       ret = regmap_read(sunrise->regmap, reg, &val);
> > +       mutex_unlock(&sunrise->wakeup_lock);
>
> Seems to me that you may redefine ->read() for regmap (but double
> check this, esp. in regard to bulk transfers) with wakeup implied and
> in that case you probably can use regmap's lock only.
>

Can you point me to an example where regmap's read is redefined ? I
failed to find one at a quick look.

> > +       if (ret) {
>
> > +               dev_err(&sunrise->client->dev,
> > +                       "Read byte failed: reg 0x%2x (%d)\n", reg, ret);
>
> With the same LOCs I slightly prefer temporary variable
>
> struct device *dev = ...;
>   ...
> dev_err(dev, ...); // on a single line
>
> Ditto everywhere.

Ugh! I initially had a *dev pointer for the sake of line length in
error messages in the driver's struct, then I'm asked to remove it,
then I'm asked to take a pointer to re-shorten the lines.

>
> > +               return ret;
> > +       }
> > +
> > +       return val;
> > +}
>
> ...
>
> > +static int sunrise_read_word(struct sunrise_dev *sunrise, u8 reg, u16 *val)
> > +{
> > +       __be16 be_val;
> > +       int ret;
> > +
> > +       mutex_lock(&sunrise->wakeup_lock);
> > +       sunrise_wakeup(sunrise);
>
> > +       ret = regmap_bulk_read(sunrise->regmap, reg, &be_val, 2);
>
> sizeof(be_val)
>

ack

> > +       mutex_unlock(&sunrise->wakeup_lock);
> > +       if (ret) {
> > +               dev_err(&sunrise->client->dev,
> > +                       "Read word failed: reg 0x%2x (%d)\n", reg, ret);
> > +               return ret;
> > +       }
> > +
> > +       *val = be16_to_cpu(be_val);
> > +
> > +       return 0;
> > +}
>
> ...
>
> > +static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data)
> > +{
> > +       __be16 be_data = cpu_to_be16(data);
> > +       int ret;
> > +
> > +       mutex_lock(&sunrise->wakeup_lock);
> > +       sunrise_wakeup(sunrise);
> > +       ret = regmap_bulk_write(sunrise->regmap, reg, &be_data, 2);
> > +       mutex_unlock(&sunrise->wakeup_lock);
> > +       if (ret) {
> > +               dev_err(&sunrise->client->dev,
> > +                       "Write word failed: reg 0x%2x (%d)\n", reg, ret);
>
> > +               return ret;
> > +       }
> > +
> > +       return 0;
>
> return ret;
>

I can return a positive value for success and change the checks around
return code to if (ret < 0) but that's driver internal stuff after
all, does it really matter ? Is this more consistent with the Linux
i2c API maybe ?  I can change it if it's the case.


> > +}
>
> ...
>
> > +       /* Write a calibration command and poll the calibration status bit. */
> > +       ret = sunrise_write_word(sunrise, SUNRISE_CALIBRATION_COMMAND_REG,
> > +                                data->cmd);
>
> Dunno how long it is, but to me seems one line is okay.
>

This is getting frustrating, and that's not completely on you.

In other subsystems I get asked to stay in the 80-cols limits no
matter what. Here there's an arbitrary limit according to the
reviewers' tastes. I feel when we had the strict 80-cols limits it was
easier as I didn't have to please each one preferences.

If I read this
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bdc48fa11e46f867ea4d75fa59ee87a7f48be144
it seems that the only relevant thing is not to break user visible
messages (which was kind of implied before), everything else goes, up
to 100-cols where you should ask yourself "what are you doing",
according to Linus words.

I've been suggested "up to 90 is probably fine", then I read 100 in
the commit message, but 80 is still _preferred_ according to the
commit message again.

I wish I could count how many characters we have typed to discuss
about this just during the review of this small driver. Seems like a
lot of churn and time to me.

> > +       if (ret)
> > +               return ret;
>
> ...
>
> > +static ssize_t sunrise_cal_read(const char *buf, size_t len)
> > +{
> > +       bool enable;
> > +       int ret;
> > +
> > +       ret = kstrtobool(buf, &enable);
> > +       if (ret)
> > +               return ret;
> > +
> > +       if (!enable)
> > +               return len;
> > +
> > +       return 0;
>
> Why is this a separate function to begin with?

Because it is called from two places where I should have duplicated
the code otherwise ?

>
> Not sure I have got the logic behind. If enable is true you return 0?!
>

Yes, so I can
        if (ret)
                return ret;
in the caller.

> > +}
>
> ...
>
> > +static ssize_t sunrise_cal_factory_write(struct iio_dev *iiodev,
> > +                                        uintptr_t private,
> > +                                        const struct iio_chan_spec *chan,
> > +                                        const char *buf, size_t len)
> > +{
> > +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> > +       int ret;
> > +
> > +       mutex_lock(&sunrise->lock);
> > +       ret = sunrise_cal_read(buf, len);
>
> > +       if (ret) {
> > +               mutex_unlock(&sunrise->lock);
> > +               return ret;
> > +       }
>
> Possibly
>
>   if (ret)
>     goto out_unlock;
>

ack

> > +       ret = sunrise_calibrate(sunrise,
> > +                               &calib_data[SUNRISE_CALIBRATION_FACTORY]);
>
> One line?
>
> out_unlock:
>
> > +       mutex_unlock(&sunrise->lock);
> > +       if (ret)
> > +               return ret;
> > +
> > +       return len;
> > +}
>
> ...
>
> > +       errors = value;
> > +       for_each_set_bit(i, &errors, ARRAY_SIZE(sunrise_error_statuses))
> > +               len += sysfs_emit_at(buf, len, "%s ", sunrise_error_statuses[i]);
>
> > +
>
> Can drop this (up to you).
>
> > +       if (len)
> > +               buf[len - 1] = '\n';
>
> ...
>
> > +                       ret = sunrise_read_word(sunrise, SUNRISE_CO2_FILTERED_COMP_REG,
> > +                                               &value);
>
> One line?
>

Ufff :)

> ...
>
> > +                       ret = sunrise_read_word(sunrise, SUNRISE_CHIP_TEMPERATURE_REG,
> > +                                               &value);
>
> Ditto.
>
> ...
>
> > +               /* x10 to comply with IIO scale (1/1000 degress celsius). */
>
> 1/1000 -->  millidegrees
> (Also note spelling)

Thanks for the spelling warning. I'll fix.

Thanks
   j

>
> --
> With Best Regards,
> Andy Shevchenko

Re: [PATCH v4 2/3] iio: chemical: Add Senseair Sunrise 006-0-007 driver

[Andy Shevchenko]

On Fri, Sep 3, 2021 at 7:42 PM Jacopo Mondi <jacopo@jmondi.org> wrote:
> On Fri, Sep 03, 2021 at 06:36:44PM +0300, Andy Shevchenko wrote:
> > On Fri, Sep 3, 2021 at 5:50 PM Jacopo Mondi <jacopo@jmondi.org> wrote:

...

> > > +       mutex_lock(&sunrise->wakeup_lock);
> > > +       sunrise_wakeup(sunrise);
> > > +       ret = regmap_read(sunrise->regmap, reg, &val);
> > > +       mutex_unlock(&sunrise->wakeup_lock);
> >
> > Seems to me that you may redefine ->read() for regmap (but double
> > check this, esp. in regard to bulk transfers) with wakeup implied and
> > in that case you probably can use regmap's lock only.
>
> Can you point me to an example where regmap's read is redefined ? I
> failed to find one at a quick look.

Any when struct regmap_config is defined with devm_regmap_i2c_init() call.

This one is not I²C, but gives you an idea.
https://elixir.bootlin.com/linux/latest/source/drivers/mfd/intel_soc_pmic_mrfld.c#L98

...

> Ugh! I initially had a *dev pointer for the sake of line length in
> error messages in the driver's struct, then I'm asked to remove it,
> then I'm asked to take a pointer to re-shorten the lines.

Up to maintainers then.

...

> > > +static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data)
> > > +{
> > > +       __be16 be_data = cpu_to_be16(data);
> > > +       int ret;
> > > +
> > > +       mutex_lock(&sunrise->wakeup_lock);
> > > +       sunrise_wakeup(sunrise);
> > > +       ret = regmap_bulk_write(sunrise->regmap, reg, &be_data, 2);
> > > +       mutex_unlock(&sunrise->wakeup_lock);
> > > +       if (ret) {
> > > +               dev_err(&sunrise->client->dev,
> > > +                       "Write word failed: reg 0x%2x (%d)\n", reg, ret);
> >
> > > +               return ret;
> > > +       }
> > > +
> > > +       return 0;
> >
> > return ret;
> >
>
> I can return a positive value for success and change the checks around
> return code to if (ret < 0) but that's driver internal stuff after
> all, does it really matter ? Is this more consistent with the Linux
> i2c API maybe ?  I can change it if it's the case.

I didn't get what this comment has with what I have proposed.

Maybe it wasn't obvious, so I have proposed to change 4 LOCs by 1 LOC, so

if (ret)
  dev_err(...);
return ret;

> > > +}

...

> > > +static ssize_t sunrise_cal_read(const char *buf, size_t len)
> > > +{
> > > +       bool enable;
> > > +       int ret;
> > > +
> > > +       ret = kstrtobool(buf, &enable);
> > > +       if (ret)
> > > +               return ret;
> > > +
> > > +       if (!enable)
> > > +               return len;
> > > +
> > > +       return 0;
> >
> > Why is this a separate function to begin with?
>
> Because it is called from two places where I should have duplicated
> the code otherwise ?

I think what you think about duplication is not and will get even LOC
benefit. Using kstrtobool() directly in the callers is better than
hiding like this.

> > Not sure I have got the logic behind. If enable is true you return 0?!
>
> Yes, so I can
>         if (ret)
>                 return ret;
> in the caller.
>
> > > +}


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 2/3] iio: chemical: Add Senseair Sunrise 006-0-007 driver

[Jonathan Cameron]

On Fri, 3 Sep 2021 23:21:05 +0300
Andy Shevchenko <andy.shevchenko@gmail.com> wrote:

> On Fri, Sep 3, 2021 at 7:42 PM Jacopo Mondi <jacopo@jmondi.org> wrote:
> > On Fri, Sep 03, 2021 at 06:36:44PM +0300, Andy Shevchenko wrote:  
> > > On Fri, Sep 3, 2021 at 5:50 PM Jacopo Mondi <jacopo@jmondi.org> wrote:  
> 
> ...
> 
> > > > +       mutex_lock(&sunrise->wakeup_lock);
> > > > +       sunrise_wakeup(sunrise);
> > > > +       ret = regmap_read(sunrise->regmap, reg, &val);
> > > > +       mutex_unlock(&sunrise->wakeup_lock);  
> > >
> > > Seems to me that you may redefine ->read() for regmap (but double
> > > check this, esp. in regard to bulk transfers) with wakeup implied and
> > > in that case you probably can use regmap's lock only.  
> >
> > Can you point me to an example where regmap's read is redefined ? I
> > failed to find one at a quick look.  
> 
> Any when struct regmap_config is defined with devm_regmap_i2c_init() call.
> 
> This one is not I²C, but gives you an idea.
> https://elixir.bootlin.com/linux/latest/source/drivers/mfd/intel_soc_pmic_mrfld.c#L98
> 
> ...
> 
> > Ugh! I initially had a *dev pointer for the sake of line length in
> > error messages in the driver's struct, then I'm asked to remove it,
> > then I'm asked to take a pointer to re-shorten the lines.  
> 
> Up to maintainers then.

Andy is requesting something different here by asking for a local
struct device *dev = sunrise->client->dev;

but personally I wouldn't bother when there is only one use in a given
function. I wouldn't mind if you did do it either - this one is very much
personal taste and so I tend to not worry about it!

Having the extra pointer in iio_priv() was a case of architecture being
a bit 'fuzzy' for convenience which is a different matter.

> 
> ...
> 
> > > > +static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data)
> > > > +{
> > > > +       __be16 be_data = cpu_to_be16(data);
> > > > +       int ret;
> > > > +
> > > > +       mutex_lock(&sunrise->wakeup_lock);
> > > > +       sunrise_wakeup(sunrise);
> > > > +       ret = regmap_bulk_write(sunrise->regmap, reg, &be_data, 2);
> > > > +       mutex_unlock(&sunrise->wakeup_lock);
> > > > +       if (ret) {
> > > > +               dev_err(&sunrise->client->dev,
> > > > +                       "Write word failed: reg 0x%2x (%d)\n", reg, ret);  
> > >  
> > > > +               return ret;
> > > > +       }
> > > > +
> > > > +       return 0;  
> > >
> > > return ret;
> > >  
> >
> > I can return a positive value for success and change the checks around
> > return code to if (ret < 0) but that's driver internal stuff after
> > all, does it really matter ? Is this more consistent with the Linux
> > i2c API maybe ?  I can change it if it's the case.  
> 
> I didn't get what this comment has with what I have proposed.
> 
> Maybe it wasn't obvious, so I have proposed to change 4 LOCs by 1 LOC, so
> 
> if (ret)
>   dev_err(...);
> return ret;

one of the checking scripts tends to moan about this so it's nice to clean it
out at the start and avoid the inevitable follow up patch :)

> 
> > > > +}  
> 
> ...
> 
> > > > +static ssize_t sunrise_cal_read(const char *buf, size_t len)
> > > > +{
> > > > +       bool enable;
> > > > +       int ret;
> > > > +
> > > > +       ret = kstrtobool(buf, &enable);
> > > > +       if (ret)
> > > > +               return ret;
> > > > +
> > > > +       if (!enable)
> > > > +               return len;
> > > > +
> > > > +       return 0;  
> > >
> > > Why is this a separate function to begin with?  
> >
> > Because it is called from two places where I should have duplicated
> > the code otherwise ?  
> 
> I think what you think about duplication is not and will get even LOC
> benefit. Using kstrtobool() directly in the callers is better than
> hiding like this.

Part of the issue here is that the naming perhaps suggests a hardware rad
whereas it's just a bit of string handling.

Whilst it's shared code, there is only a rather tangential connection between
the two call sites and the function itself ended up a bit weird.

I'd go with what Andy is suggesting and just have this handling inline.


> 
> > > Not sure I have got the logic behind. If enable is true you return 0?!  
> >
> > Yes, so I can
> >         if (ret)
> >                 return ret;
> > in the caller.
> >  
> > > > +}  
> 
> 

Re: [PATCH v4 2/3] iio: chemical: Add Senseair Sunrise 006-0-007 driver

[Matt Ranostay]

On Fri, Sep 3, 2021 at 7:48 AM Jacopo Mondi <jacopo@jmondi.org> wrote:
>
> Add support for the Senseair Sunrise 006-0-0007 driver through the
> IIO subsystem.
>
> Datasheet: https://rmtplusstoragesenseair.blob.core.windows.net/docs/Dev/publicerat/TDE5531.pdf
> Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
> ---
>  MAINTAINERS                        |   6 +
>  drivers/iio/chemical/Kconfig       |  10 +
>  drivers/iio/chemical/Makefile      |   1 +
>  drivers/iio/chemical/sunrise_co2.c | 487 +++++++++++++++++++++++++++++
>  4 files changed, 504 insertions(+)
>  create mode 100644 drivers/iio/chemical/sunrise_co2.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d7b4f32875a9..a8b859297e9e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -16723,6 +16723,12 @@ S:     Maintained
>  F:     drivers/misc/phantom.c
>  F:     include/uapi/linux/phantom.h
>
> +SENSEAIR SUNRISE 006-0-0007
> +M:     Jacopo Mondi <jacopo@jmondi.org>
> +S:     Maintained
> +F:     Documentation/devicetree/bindings/iio/chemical/senseair,sunrise.yaml
> +F:     drivers/iio/chemical/sunrise_co2.c
> +
>  SENSIRION SCD30 CARBON DIOXIDE SENSOR DRIVER
>  M:     Tomasz Duszynski <tomasz.duszynski@octakon.com>
>  S:     Maintained
> diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
> index a4920646e9be..5155ab2caed4 100644
> --- a/drivers/iio/chemical/Kconfig
> +++ b/drivers/iio/chemical/Kconfig
> @@ -159,6 +159,16 @@ config SPS30_SERIAL
>           To compile this driver as a module, choose M here: the module will
>           be called sps30_serial.
>
> +config SENSEAIR_SUNRISE_CO2
> +       tristate "Senseair Sunrise 006-0-0007 CO2 sensor"
> +       select REGMAP_I2C
> +       help
> +         Say yes here to build support for Senseair Sunrise 006-0-0007 CO2
> +         sensor.
> +
> +         To compile this driver as a module, choose M here: the
> +         module will be called sunrise_co2.
> +
>  config VZ89X
>         tristate "SGX Sensortech MiCS VZ89X VOC sensor"
>         depends on I2C
> diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
> index 4898690cc155..61e8749a84f3 100644
> --- a/drivers/iio/chemical/Makefile
> +++ b/drivers/iio/chemical/Makefile
> @@ -15,6 +15,7 @@ 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-$(CONFIG_SENSEAIR_SUNRISE_CO2) += sunrise_co2.o
>  obj-$(CONFIG_SENSIRION_SGP30)  += sgp30.o
>  obj-$(CONFIG_SPS30) += sps30.o
>  obj-$(CONFIG_SPS30_I2C) += sps30_i2c.o
> diff --git a/drivers/iio/chemical/sunrise_co2.c b/drivers/iio/chemical/sunrise_co2.c
> new file mode 100644
> index 000000000000..cf15cdbaa24a
> --- /dev/null
> +++ b/drivers/iio/chemical/sunrise_co2.c
> @@ -0,0 +1,487 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Senseair Sunrise 006-0-0007 CO2 sensor driver.
> + *
> + * Copyright (C) 2021 Jacopo Mondi
> + *
> + * List of features not yet supported by the driver:
> + * - controllable EN pin
> + * - single-shot operations using the nDRY pin.
> + * - ABC/target calibration
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/regmap.h>
> +#include <linux/time64.h>
> +
> +#include <linux/iio/iio.h>
> +
> +#define DRIVER_NAME "sunrise_co2"
> +
> +#define SUNRISE_ERROR_STATUS_REG               0x00
> +#define SUNRISE_CO2_FILTERED_COMP_REG          0x06
> +#define SUNRISE_CHIP_TEMPERATURE_REG           0x08
> +#define SUNRISE_CALIBRATION_STATUS_REG         0x81
> +#define SUNRISE_CALIBRATION_COMMAND_REG                0x82
> +#define SUNRISE_CALIBRATION_FACTORY_CMD                0x7c02
> +#define SUNRISE_CALIBRATION_BACKGROUND_CMD     0x7c06
> +/*
> + * The calibration timeout is not characterized in the datasheet.
> + * Use 30 seconds as a reasonable upper limit.
> + */
> +#define SUNRISE_CALIBRATION_TIMEOUT_US         (30 * USEC_PER_SEC)
> +
> +struct sunrise_dev {
> +       struct i2c_client *client;
> +       struct regmap *regmap;
> +       /* Protects access to IIO attributes. */
> +       struct mutex lock;
> +       /* Protects chip's wakup session. */
> +       struct mutex wakeup_lock;
> +};
> +
> +static void sunrise_wakeup(struct sunrise_dev *sunrise)
> +{
> +       struct i2c_client *client = sunrise->client;
> +
> +       /*
> +        * Wake up sensor by sending sensor address: START, sensor address,
> +        * STOP. Sensor will not ACK this byte.
> +        *
> +        * The chip returns in low power state after 15msec without
> +        * communications or after a complete read/write sequence.
> +        */
> +       i2c_smbus_xfer(client->adapter, client->addr, I2C_M_IGNORE_NAK,
> +                      I2C_SMBUS_WRITE, 0, I2C_SMBUS_QUICK, NULL);
> +}
> +
> +static int sunrise_read_byte(struct sunrise_dev *sunrise, u8 reg)
> +{
> +       unsigned int val;
> +       int ret;
> +
> +       /*
> +        * Lock the 'wakeup' session.
> +        *
> +        * If another read/write call sneaks in between the wakeup message
> +        * and the i2c transaction, the chip goes back in sleep state.
> +        */
> +       mutex_lock(&sunrise->wakeup_lock);
> +       sunrise_wakeup(sunrise);
> +       ret = regmap_read(sunrise->regmap, reg, &val);
> +       mutex_unlock(&sunrise->wakeup_lock);
> +       if (ret) {
> +               dev_err(&sunrise->client->dev,
> +                       "Read byte failed: reg 0x%2x (%d)\n", reg, ret);
> +               return ret;
> +       }
> +
> +       return val;
> +}
> +
> +static int sunrise_read_word(struct sunrise_dev *sunrise, u8 reg, u16 *val)
> +{
> +       __be16 be_val;
> +       int ret;
> +
> +       mutex_lock(&sunrise->wakeup_lock);
> +       sunrise_wakeup(sunrise);
> +       ret = regmap_bulk_read(sunrise->regmap, reg, &be_val, 2);
> +       mutex_unlock(&sunrise->wakeup_lock);
> +       if (ret) {
> +               dev_err(&sunrise->client->dev,
> +                       "Read word failed: reg 0x%2x (%d)\n", reg, ret);
> +               return ret;
> +       }
> +
> +       *val = be16_to_cpu(be_val);
> +
> +       return 0;
> +}
> +
> +static int sunrise_write_byte(struct sunrise_dev *sunrise, u8 reg, u8 val)
> +{
> +       int ret;
> +
> +       mutex_lock(&sunrise->wakeup_lock);
> +       sunrise_wakeup(sunrise);
> +       ret = regmap_write(sunrise->regmap, reg, val);
> +       mutex_unlock(&sunrise->wakeup_lock);
> +       if (ret) {
> +               dev_err(&sunrise->client->dev,
> +                       "Write byte failed: reg 0x%2x (%d)\n", reg, ret);
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data)
> +{
> +       __be16 be_data = cpu_to_be16(data);
> +       int ret;
> +
> +       mutex_lock(&sunrise->wakeup_lock);
> +       sunrise_wakeup(sunrise);
> +       ret = regmap_bulk_write(sunrise->regmap, reg, &be_data, 2);
> +       mutex_unlock(&sunrise->wakeup_lock);
> +       if (ret) {
> +               dev_err(&sunrise->client->dev,
> +                       "Write word failed: reg 0x%2x (%d)\n", reg, ret);
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +/* Trigger a calibration cycle. */
> +
> +enum {
> +       SUNRISE_CALIBRATION_FACTORY,
> +       SUNRISE_CALIBRATION_BACKGROUND,
> +};
> +
> +static const struct sunrise_calib_data {
> +       u16 cmd;
> +       u8 bit;
> +       const char * const name;
> +} calib_data[] = {
> +       [SUNRISE_CALIBRATION_FACTORY] = {
> +               SUNRISE_CALIBRATION_FACTORY_CMD,
> +               BIT(2),
> +               "factory_calibration",
> +       },
> +       [SUNRISE_CALIBRATION_BACKGROUND] = {
> +               SUNRISE_CALIBRATION_BACKGROUND_CMD,
> +               BIT(5),
> +               "background_calibration",
> +       },
> +};
> +
> +static int sunrise_calibrate(struct sunrise_dev *sunrise,
> +                            const struct sunrise_calib_data *data)
> +{
> +       unsigned int status;
> +       int ret;
> +
> +       /* Reset the calibration status reg. */
> +       ret = sunrise_write_byte(sunrise, SUNRISE_CALIBRATION_STATUS_REG, 0x00);
> +       if (ret)
> +               return ret;
> +
> +       /* Write a calibration command and poll the calibration status bit. */
> +       ret = sunrise_write_word(sunrise, SUNRISE_CALIBRATION_COMMAND_REG,
> +                                data->cmd);
> +       if (ret)
> +               return ret;
> +
> +       dev_dbg(&sunrise->client->dev, "%s in progress\n", data->name);
> +
> +       /*
> +        * Calibration takes several seconds, so the sleep time between reads
> +        * can be pretty relaxed.
> +        */
> +       return read_poll_timeout(sunrise_read_byte, status,
> +                                status & data->bit, 200000,
> +                                SUNRISE_CALIBRATION_TIMEOUT_US, false,
> +                                sunrise, SUNRISE_CALIBRATION_STATUS_REG);
> +}
> +
> +static ssize_t sunrise_cal_read(const char *buf, size_t len)
> +{
> +       bool enable;
> +       int ret;
> +
> +       ret = kstrtobool(buf, &enable);
> +       if (ret)
> +               return ret;
> +
> +       if (!enable)
> +               return len;
> +
> +       return 0;
> +}
> +
> +static ssize_t sunrise_cal_factory_write(struct iio_dev *iiodev,
> +                                        uintptr_t private,
> +                                        const struct iio_chan_spec *chan,
> +                                        const char *buf, size_t len)
> +{
> +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> +       int ret;
> +
> +       mutex_lock(&sunrise->lock);
> +       ret = sunrise_cal_read(buf, len);
> +       if (ret) {
> +               mutex_unlock(&sunrise->lock);
> +               return ret;
> +       }
> +
> +       ret = sunrise_calibrate(sunrise,
> +                               &calib_data[SUNRISE_CALIBRATION_FACTORY]);
> +       mutex_unlock(&sunrise->lock);
> +       if (ret)
> +               return ret;
> +
> +       return len;
> +}
> +
> +static ssize_t sunrise_cal_background_write(struct iio_dev *iiodev,
> +                                           uintptr_t private,
> +                                           const struct iio_chan_spec *chan,
> +                                           const char *buf, size_t len)
> +{
> +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> +       int ret;
> +
> +       mutex_lock(&sunrise->lock);
> +       ret = sunrise_cal_read(buf, len);
> +       if (ret) {
> +               mutex_unlock(&sunrise->lock);
> +               return ret;
> +       }
> +
> +       ret = sunrise_calibrate(sunrise,
> +                               &calib_data[SUNRISE_CALIBRATION_BACKGROUND]);
> +       mutex_unlock(&sunrise->lock);
> +       if (ret)
> +               return ret;
> +
> +       return len;
> +}
> +
> + /* Enumerate and retrieve the chip error status. */
> +enum {
> +       SUNRISE_ERROR_FATAL,
> +       SUNRISE_ERROR_I2C,
> +       SUNRISE_ERROR_ALGORITHM,
> +       SUNRISE_ERROR_CALIBRATION,
> +       SUNRISE_ERROR_SELF_DIAGNOSTIC,
> +       SUNRISE_ERROR_OUT_OF_RANGE,
> +       SUNRISE_ERROR_MEMORY,
> +       SUNRISE_ERROR_NO_MEASUREMENT,
> +       SUNRISE_ERROR_LOW_VOLTAGE,
> +       SUNRISE_ERROR_MEASUREMENT_TIMEOUT,
> +};
> +
> +static const char * const sunrise_error_statuses[] = {
> +       [SUNRISE_ERROR_FATAL] = "error_fatal",
> +       [SUNRISE_ERROR_I2C] = "error_i2c",
> +       [SUNRISE_ERROR_ALGORITHM] = "error_algorithm",
> +       [SUNRISE_ERROR_CALIBRATION] = "error_calibration",
> +       [SUNRISE_ERROR_SELF_DIAGNOSTIC] = "error_self_diagnostic",
> +       [SUNRISE_ERROR_OUT_OF_RANGE] = "error_out_of_range",
> +       [SUNRISE_ERROR_MEMORY] = "error_memory",
> +       [SUNRISE_ERROR_NO_MEASUREMENT] = "error_no_measurement",
> +       [SUNRISE_ERROR_LOW_VOLTAGE] = "error_low_voltage",
> +       [SUNRISE_ERROR_MEASUREMENT_TIMEOUT] = "error_measurement_timeout",
> +};
> +
> +static const struct iio_enum sunrise_error_statuses_enum = {
> +       .items = sunrise_error_statuses,
> +       .num_items = ARRAY_SIZE(sunrise_error_statuses),
> +};
> +
> +static ssize_t sunrise_error_status_read(struct iio_dev *iiodev,
> +                                        uintptr_t private,
> +                                        const struct iio_chan_spec *chan,
> +                                        char *buf)
> +{
> +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> +       unsigned long errors;
> +       ssize_t len = 0;
> +       u16 value;
> +       int ret;
> +       u8 i;
> +
> +       mutex_lock(&sunrise->lock);
> +       ret = sunrise_read_word(sunrise, SUNRISE_ERROR_STATUS_REG, &value);
> +       if (ret) {
> +               mutex_unlock(&sunrise->lock);
> +               return -EINVAL;
> +       }
> +
> +       errors = value;
> +       for_each_set_bit(i, &errors, ARRAY_SIZE(sunrise_error_statuses))
> +               len += sysfs_emit_at(buf, len, "%s ", sunrise_error_statuses[i]);
> +
> +       if (len)
> +               buf[len - 1] = '\n';
> +
> +       mutex_unlock(&sunrise->lock);
> +
> +       return len;
> +}
> +
> +static const struct iio_chan_spec_ext_info sunrise_concentration_ext_info[] = {
> +       /* Calibration triggers. */
> +       {
> +               .name = "calibration_factory",
> +               .write = sunrise_cal_factory_write,
> +               .shared = IIO_SEPARATE,
> +       },
> +       {
> +               .name = "calibration_background",
> +               .write = sunrise_cal_background_write,
> +               .shared = IIO_SEPARATE,
> +       },
> +
> +       /* Error statuses. */
> +       {
> +               .name = "error_status",
> +               .read = sunrise_error_status_read,
> +               .shared = IIO_SHARED_BY_ALL,
> +       },
> +       {
> +               .name = "error_status_available",
> +               .shared = IIO_SHARED_BY_ALL,
> +               .read = iio_enum_available_read,
> +               .private = (uintptr_t)&sunrise_error_statuses_enum,
> +       },
> +       {}
> +};
> +
> +static const struct iio_chan_spec sunrise_channels[] = {
> +       {
> +               .type = IIO_CONCENTRATION,
> +               .modified = 1,
> +               .channel2 = IIO_MOD_CO2,
> +               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),

Why isn't there a IIO_CHAN_INFO_SCALE for the CO2 channel?  Raw units
between different CO2 sensors aren't always in ppm

Thanks,

Matt

> +               .ext_info = sunrise_concentration_ext_info,
> +               .scan_index = 0,
> +               .scan_type =  {
> +                       .sign = 's',
> +                       .realbits = 16,
> +                       .storagebits = 16,
> +                       .endianness = IIO_CPU,
> +               },
> +       },
> +       {
> +               .type = IIO_TEMP,
> +               .info_mask_separate =  BIT(IIO_CHAN_INFO_RAW) |
> +                                      BIT(IIO_CHAN_INFO_SCALE),
> +               .scan_index = 1,
> +               .scan_type =  {
> +                       .sign = 's',
> +                       .realbits = 16,
> +                       .storagebits = 16,
> +                       .endianness = IIO_CPU,
> +               },
> +       },
> +};
> +
> +static int sunrise_read_raw(struct iio_dev *iio_dev,
> +                           const struct iio_chan_spec *chan,
> +                           int *val, int *val2, long mask)
> +{
> +       struct sunrise_dev *sunrise = iio_priv(iio_dev);
> +       u16 value;
> +       int ret;
> +
> +       switch (mask) {
> +       case IIO_CHAN_INFO_RAW:
> +               switch (chan->type) {
> +               case IIO_CONCENTRATION:
> +                       mutex_lock(&sunrise->lock);
> +                       ret = sunrise_read_word(sunrise, SUNRISE_CO2_FILTERED_COMP_REG,
> +                                               &value);
> +                       *val = value;
> +                       mutex_unlock(&sunrise->lock);
> +
> +                       if (ret)
> +                               return ret;
> +
> +                       return IIO_VAL_INT;
> +
> +               case IIO_TEMP:
> +                       mutex_lock(&sunrise->lock);
> +                       ret = sunrise_read_word(sunrise, SUNRISE_CHIP_TEMPERATURE_REG,
> +                                               &value);
> +                       *val = value;
> +                       mutex_unlock(&sunrise->lock);
> +
> +                       if (ret)
> +                               return ret;
> +
> +                       return IIO_VAL_INT;
> +
> +               default:
> +                       return -EINVAL;
> +               }
> +
> +       case IIO_CHAN_INFO_SCALE:
> +               /* x10 to comply with IIO scale (1/1000 degress celsius). */
> +               *val = 10;
> +               return IIO_VAL_INT;
> +
> +       default:
> +               return -EINVAL;
> +       }
> +}
> +
> +static const struct iio_info sunrise_info = {
> +       .read_raw = sunrise_read_raw,
> +};
> +
> +static struct regmap_config sunrise_regmap_config = {
> +       .reg_bits = 8,
> +       .val_bits = 8,
> +       /*
> +        * Access to the i2c bus is locked by the driver to preserve the
> +        * 'wakeup' session.
> +        */
> +       .disable_locking = true,
> +};
> +
> +static int sunrise_probe(struct i2c_client *client)
> +{
> +       struct sunrise_dev *sunrise;
> +       struct iio_dev *iio_dev;
> +
> +       iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*sunrise));
> +       if (!iio_dev)
> +               return -ENOMEM;
> +
> +       sunrise = iio_priv(iio_dev);
> +       sunrise->client = client;
> +       mutex_init(&sunrise->lock);
> +       mutex_init(&sunrise->wakeup_lock);
> +
> +       sunrise->regmap = devm_regmap_init_i2c(client, &sunrise_regmap_config);
> +       if (IS_ERR(sunrise->regmap)) {
> +               dev_err(&client->dev, "Failed to initialize regmap\n");
> +               return PTR_ERR(sunrise->regmap);
> +       }
> +
> +       iio_dev->info = &sunrise_info;
> +       iio_dev->name = DRIVER_NAME;
> +       iio_dev->channels = sunrise_channels;
> +       iio_dev->num_channels = ARRAY_SIZE(sunrise_channels);
> +       iio_dev->modes = INDIO_DIRECT_MODE;
> +
> +       return devm_iio_device_register(&client->dev, iio_dev);
> +}
> +
> +static const struct of_device_id sunrise_of_match[] = {
> +       { .compatible = "senseair,sunrise-006-0-0007" },
> +       {}
> +};
> +MODULE_DEVICE_TABLE(of, sunrise_of_match);
> +
> +static struct i2c_driver sunrise_driver = {
> +       .driver = {
> +               .name = DRIVER_NAME,
> +               .of_match_table = sunrise_of_match,
> +       },
> +       .probe_new = sunrise_probe,
> +};
> +module_i2c_driver(sunrise_driver);
> +
> +MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>");
> +MODULE_DESCRIPTION("Senseair Sunrise 006-0-0007 CO2 sensor IIO driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.32.0
>

Re: [PATCH v4 2/3] iio: chemical: Add Senseair Sunrise 006-0-007 driver

[Jacopo Mondi]

Hi Matt,

On Sun, Sep 05, 2021 at 02:10:43PM -0700, Matt Ranostay wrote:
> On Fri, Sep 3, 2021 at 7:48 AM Jacopo Mondi <jacopo@jmondi.org> wrote:
> >
> > Add support for the Senseair Sunrise 006-0-0007 driver through the
> > IIO subsystem.
> >
> > Datasheet: https://rmtplusstoragesenseair.blob.core.windows.net/docs/Dev/publicerat/TDE5531.pdf
> > Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
> > ---
> >  MAINTAINERS                        |   6 +
> >  drivers/iio/chemical/Kconfig       |  10 +
> >  drivers/iio/chemical/Makefile      |   1 +
> >  drivers/iio/chemical/sunrise_co2.c | 487 +++++++++++++++++++++++++++++
> >  4 files changed, 504 insertions(+)
> >  create mode 100644 drivers/iio/chemical/sunrise_co2.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index d7b4f32875a9..a8b859297e9e 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -16723,6 +16723,12 @@ S:     Maintained
> >  F:     drivers/misc/phantom.c
> >  F:     include/uapi/linux/phantom.h
> >
> > +SENSEAIR SUNRISE 006-0-0007
> > +M:     Jacopo Mondi <jacopo@jmondi.org>
> > +S:     Maintained
> > +F:     Documentation/devicetree/bindings/iio/chemical/senseair,sunrise.yaml
> > +F:     drivers/iio/chemical/sunrise_co2.c
> > +
> >  SENSIRION SCD30 CARBON DIOXIDE SENSOR DRIVER
> >  M:     Tomasz Duszynski <tomasz.duszynski@octakon.com>
> >  S:     Maintained
> > diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
> > index a4920646e9be..5155ab2caed4 100644
> > --- a/drivers/iio/chemical/Kconfig
> > +++ b/drivers/iio/chemical/Kconfig
> > @@ -159,6 +159,16 @@ config SPS30_SERIAL
> >           To compile this driver as a module, choose M here: the module will
> >           be called sps30_serial.
> >
> > +config SENSEAIR_SUNRISE_CO2
> > +       tristate "Senseair Sunrise 006-0-0007 CO2 sensor"
> > +       select REGMAP_I2C
> > +       help
> > +         Say yes here to build support for Senseair Sunrise 006-0-0007 CO2
> > +         sensor.
> > +
> > +         To compile this driver as a module, choose M here: the
> > +         module will be called sunrise_co2.
> > +
> >  config VZ89X
> >         tristate "SGX Sensortech MiCS VZ89X VOC sensor"
> >         depends on I2C
> > diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
> > index 4898690cc155..61e8749a84f3 100644
> > --- a/drivers/iio/chemical/Makefile
> > +++ b/drivers/iio/chemical/Makefile
> > @@ -15,6 +15,7 @@ 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-$(CONFIG_SENSEAIR_SUNRISE_CO2) += sunrise_co2.o
> >  obj-$(CONFIG_SENSIRION_SGP30)  += sgp30.o
> >  obj-$(CONFIG_SPS30) += sps30.o
> >  obj-$(CONFIG_SPS30_I2C) += sps30_i2c.o
> > diff --git a/drivers/iio/chemical/sunrise_co2.c b/drivers/iio/chemical/sunrise_co2.c
> > new file mode 100644
> > index 000000000000..cf15cdbaa24a
> > --- /dev/null
> > +++ b/drivers/iio/chemical/sunrise_co2.c
> > @@ -0,0 +1,487 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Senseair Sunrise 006-0-0007 CO2 sensor driver.
> > + *
> > + * Copyright (C) 2021 Jacopo Mondi
> > + *
> > + * List of features not yet supported by the driver:
> > + * - controllable EN pin
> > + * - single-shot operations using the nDRY pin.
> > + * - ABC/target calibration
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/i2c.h>
> > +#include <linux/kernel.h>
> > +#include <linux/mod_devicetable.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/regmap.h>
> > +#include <linux/time64.h>
> > +
> > +#include <linux/iio/iio.h>
> > +
> > +#define DRIVER_NAME "sunrise_co2"
> > +
> > +#define SUNRISE_ERROR_STATUS_REG               0x00
> > +#define SUNRISE_CO2_FILTERED_COMP_REG          0x06
> > +#define SUNRISE_CHIP_TEMPERATURE_REG           0x08
> > +#define SUNRISE_CALIBRATION_STATUS_REG         0x81
> > +#define SUNRISE_CALIBRATION_COMMAND_REG                0x82
> > +#define SUNRISE_CALIBRATION_FACTORY_CMD                0x7c02
> > +#define SUNRISE_CALIBRATION_BACKGROUND_CMD     0x7c06
> > +/*
> > + * The calibration timeout is not characterized in the datasheet.
> > + * Use 30 seconds as a reasonable upper limit.
> > + */
> > +#define SUNRISE_CALIBRATION_TIMEOUT_US         (30 * USEC_PER_SEC)
> > +
> > +struct sunrise_dev {
> > +       struct i2c_client *client;
> > +       struct regmap *regmap;
> > +       /* Protects access to IIO attributes. */
> > +       struct mutex lock;
> > +       /* Protects chip's wakup session. */
> > +       struct mutex wakeup_lock;
> > +};
> > +
> > +static void sunrise_wakeup(struct sunrise_dev *sunrise)
> > +{
> > +       struct i2c_client *client = sunrise->client;
> > +
> > +       /*
> > +        * Wake up sensor by sending sensor address: START, sensor address,
> > +        * STOP. Sensor will not ACK this byte.
> > +        *
> > +        * The chip returns in low power state after 15msec without
> > +        * communications or after a complete read/write sequence.
> > +        */
> > +       i2c_smbus_xfer(client->adapter, client->addr, I2C_M_IGNORE_NAK,
> > +                      I2C_SMBUS_WRITE, 0, I2C_SMBUS_QUICK, NULL);
> > +}
> > +
> > +static int sunrise_read_byte(struct sunrise_dev *sunrise, u8 reg)
> > +{
> > +       unsigned int val;
> > +       int ret;
> > +
> > +       /*
> > +        * Lock the 'wakeup' session.
> > +        *
> > +        * If another read/write call sneaks in between the wakeup message
> > +        * and the i2c transaction, the chip goes back in sleep state.
> > +        */
> > +       mutex_lock(&sunrise->wakeup_lock);
> > +       sunrise_wakeup(sunrise);
> > +       ret = regmap_read(sunrise->regmap, reg, &val);
> > +       mutex_unlock(&sunrise->wakeup_lock);
> > +       if (ret) {
> > +               dev_err(&sunrise->client->dev,
> > +                       "Read byte failed: reg 0x%2x (%d)\n", reg, ret);
> > +               return ret;
> > +       }
> > +
> > +       return val;
> > +}
> > +
> > +static int sunrise_read_word(struct sunrise_dev *sunrise, u8 reg, u16 *val)
> > +{
> > +       __be16 be_val;
> > +       int ret;
> > +
> > +       mutex_lock(&sunrise->wakeup_lock);
> > +       sunrise_wakeup(sunrise);
> > +       ret = regmap_bulk_read(sunrise->regmap, reg, &be_val, 2);
> > +       mutex_unlock(&sunrise->wakeup_lock);
> > +       if (ret) {
> > +               dev_err(&sunrise->client->dev,
> > +                       "Read word failed: reg 0x%2x (%d)\n", reg, ret);
> > +               return ret;
> > +       }
> > +
> > +       *val = be16_to_cpu(be_val);
> > +
> > +       return 0;
> > +}
> > +
> > +static int sunrise_write_byte(struct sunrise_dev *sunrise, u8 reg, u8 val)
> > +{
> > +       int ret;
> > +
> > +       mutex_lock(&sunrise->wakeup_lock);
> > +       sunrise_wakeup(sunrise);
> > +       ret = regmap_write(sunrise->regmap, reg, val);
> > +       mutex_unlock(&sunrise->wakeup_lock);
> > +       if (ret) {
> > +               dev_err(&sunrise->client->dev,
> > +                       "Write byte failed: reg 0x%2x (%d)\n", reg, ret);
> > +               return ret;
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data)
> > +{
> > +       __be16 be_data = cpu_to_be16(data);
> > +       int ret;
> > +
> > +       mutex_lock(&sunrise->wakeup_lock);
> > +       sunrise_wakeup(sunrise);
> > +       ret = regmap_bulk_write(sunrise->regmap, reg, &be_data, 2);
> > +       mutex_unlock(&sunrise->wakeup_lock);
> > +       if (ret) {
> > +               dev_err(&sunrise->client->dev,
> > +                       "Write word failed: reg 0x%2x (%d)\n", reg, ret);
> > +               return ret;
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +/* Trigger a calibration cycle. */
> > +
> > +enum {
> > +       SUNRISE_CALIBRATION_FACTORY,
> > +       SUNRISE_CALIBRATION_BACKGROUND,
> > +};
> > +
> > +static const struct sunrise_calib_data {
> > +       u16 cmd;
> > +       u8 bit;
> > +       const char * const name;
> > +} calib_data[] = {
> > +       [SUNRISE_CALIBRATION_FACTORY] = {
> > +               SUNRISE_CALIBRATION_FACTORY_CMD,
> > +               BIT(2),
> > +               "factory_calibration",
> > +       },
> > +       [SUNRISE_CALIBRATION_BACKGROUND] = {
> > +               SUNRISE_CALIBRATION_BACKGROUND_CMD,
> > +               BIT(5),
> > +               "background_calibration",
> > +       },
> > +};
> > +
> > +static int sunrise_calibrate(struct sunrise_dev *sunrise,
> > +                            const struct sunrise_calib_data *data)
> > +{
> > +       unsigned int status;
> > +       int ret;
> > +
> > +       /* Reset the calibration status reg. */
> > +       ret = sunrise_write_byte(sunrise, SUNRISE_CALIBRATION_STATUS_REG, 0x00);
> > +       if (ret)
> > +               return ret;
> > +
> > +       /* Write a calibration command and poll the calibration status bit. */
> > +       ret = sunrise_write_word(sunrise, SUNRISE_CALIBRATION_COMMAND_REG,
> > +                                data->cmd);
> > +       if (ret)
> > +               return ret;
> > +
> > +       dev_dbg(&sunrise->client->dev, "%s in progress\n", data->name);
> > +
> > +       /*
> > +        * Calibration takes several seconds, so the sleep time between reads
> > +        * can be pretty relaxed.
> > +        */
> > +       return read_poll_timeout(sunrise_read_byte, status,
> > +                                status & data->bit, 200000,
> > +                                SUNRISE_CALIBRATION_TIMEOUT_US, false,
> > +                                sunrise, SUNRISE_CALIBRATION_STATUS_REG);
> > +}
> > +
> > +static ssize_t sunrise_cal_read(const char *buf, size_t len)
> > +{
> > +       bool enable;
> > +       int ret;
> > +
> > +       ret = kstrtobool(buf, &enable);
> > +       if (ret)
> > +               return ret;
> > +
> > +       if (!enable)
> > +               return len;
> > +
> > +       return 0;
> > +}
> > +
> > +static ssize_t sunrise_cal_factory_write(struct iio_dev *iiodev,
> > +                                        uintptr_t private,
> > +                                        const struct iio_chan_spec *chan,
> > +                                        const char *buf, size_t len)
> > +{
> > +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> > +       int ret;
> > +
> > +       mutex_lock(&sunrise->lock);
> > +       ret = sunrise_cal_read(buf, len);
> > +       if (ret) {
> > +               mutex_unlock(&sunrise->lock);
> > +               return ret;
> > +       }
> > +
> > +       ret = sunrise_calibrate(sunrise,
> > +                               &calib_data[SUNRISE_CALIBRATION_FACTORY]);
> > +       mutex_unlock(&sunrise->lock);
> > +       if (ret)
> > +               return ret;
> > +
> > +       return len;
> > +}
> > +
> > +static ssize_t sunrise_cal_background_write(struct iio_dev *iiodev,
> > +                                           uintptr_t private,
> > +                                           const struct iio_chan_spec *chan,
> > +                                           const char *buf, size_t len)
> > +{
> > +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> > +       int ret;
> > +
> > +       mutex_lock(&sunrise->lock);
> > +       ret = sunrise_cal_read(buf, len);
> > +       if (ret) {
> > +               mutex_unlock(&sunrise->lock);
> > +               return ret;
> > +       }
> > +
> > +       ret = sunrise_calibrate(sunrise,
> > +                               &calib_data[SUNRISE_CALIBRATION_BACKGROUND]);
> > +       mutex_unlock(&sunrise->lock);
> > +       if (ret)
> > +               return ret;
> > +
> > +       return len;
> > +}
> > +
> > + /* Enumerate and retrieve the chip error status. */
> > +enum {
> > +       SUNRISE_ERROR_FATAL,
> > +       SUNRISE_ERROR_I2C,
> > +       SUNRISE_ERROR_ALGORITHM,
> > +       SUNRISE_ERROR_CALIBRATION,
> > +       SUNRISE_ERROR_SELF_DIAGNOSTIC,
> > +       SUNRISE_ERROR_OUT_OF_RANGE,
> > +       SUNRISE_ERROR_MEMORY,
> > +       SUNRISE_ERROR_NO_MEASUREMENT,
> > +       SUNRISE_ERROR_LOW_VOLTAGE,
> > +       SUNRISE_ERROR_MEASUREMENT_TIMEOUT,
> > +};
> > +
> > +static const char * const sunrise_error_statuses[] = {
> > +       [SUNRISE_ERROR_FATAL] = "error_fatal",
> > +       [SUNRISE_ERROR_I2C] = "error_i2c",
> > +       [SUNRISE_ERROR_ALGORITHM] = "error_algorithm",
> > +       [SUNRISE_ERROR_CALIBRATION] = "error_calibration",
> > +       [SUNRISE_ERROR_SELF_DIAGNOSTIC] = "error_self_diagnostic",
> > +       [SUNRISE_ERROR_OUT_OF_RANGE] = "error_out_of_range",
> > +       [SUNRISE_ERROR_MEMORY] = "error_memory",
> > +       [SUNRISE_ERROR_NO_MEASUREMENT] = "error_no_measurement",
> > +       [SUNRISE_ERROR_LOW_VOLTAGE] = "error_low_voltage",
> > +       [SUNRISE_ERROR_MEASUREMENT_TIMEOUT] = "error_measurement_timeout",
> > +};
> > +
> > +static const struct iio_enum sunrise_error_statuses_enum = {
> > +       .items = sunrise_error_statuses,
> > +       .num_items = ARRAY_SIZE(sunrise_error_statuses),
> > +};
> > +
> > +static ssize_t sunrise_error_status_read(struct iio_dev *iiodev,
> > +                                        uintptr_t private,
> > +                                        const struct iio_chan_spec *chan,
> > +                                        char *buf)
> > +{
> > +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> > +       unsigned long errors;
> > +       ssize_t len = 0;
> > +       u16 value;
> > +       int ret;
> > +       u8 i;
> > +
> > +       mutex_lock(&sunrise->lock);
> > +       ret = sunrise_read_word(sunrise, SUNRISE_ERROR_STATUS_REG, &value);
> > +       if (ret) {
> > +               mutex_unlock(&sunrise->lock);
> > +               return -EINVAL;
> > +       }
> > +
> > +       errors = value;
> > +       for_each_set_bit(i, &errors, ARRAY_SIZE(sunrise_error_statuses))
> > +               len += sysfs_emit_at(buf, len, "%s ", sunrise_error_statuses[i]);
> > +
> > +       if (len)
> > +               buf[len - 1] = '\n';
> > +
> > +       mutex_unlock(&sunrise->lock);
> > +
> > +       return len;
> > +}
> > +
> > +static const struct iio_chan_spec_ext_info sunrise_concentration_ext_info[] = {
> > +       /* Calibration triggers. */
> > +       {
> > +               .name = "calibration_factory",
> > +               .write = sunrise_cal_factory_write,
> > +               .shared = IIO_SEPARATE,
> > +       },
> > +       {
> > +               .name = "calibration_background",
> > +               .write = sunrise_cal_background_write,
> > +               .shared = IIO_SEPARATE,
> > +       },
> > +
> > +       /* Error statuses. */
> > +       {
> > +               .name = "error_status",
> > +               .read = sunrise_error_status_read,
> > +               .shared = IIO_SHARED_BY_ALL,
> > +       },
> > +       {
> > +               .name = "error_status_available",
> > +               .shared = IIO_SHARED_BY_ALL,
> > +               .read = iio_enum_available_read,
> > +               .private = (uintptr_t)&sunrise_error_statuses_enum,
> > +       },
> > +       {}
> > +};
> > +
> > +static const struct iio_chan_spec sunrise_channels[] = {
> > +       {
> > +               .type = IIO_CONCENTRATION,
> > +               .modified = 1,
> > +               .channel2 = IIO_MOD_CO2,
> > +               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
>
> Why isn't there a IIO_CHAN_INFO_SCALE for the CO2 channel?  Raw units
> between different CO2 sensors aren't always in ppm

Good point, I should add one. The reson I didn't do so is that
Documentation/ABI/testing/sysfs-bus-iio doesn't report any
in_concentration_co2_scale attribute. Should it be added ?

Although I see this:

static IIO_CONST_ATTR(in_concentration_co2_scale, "0.00000698689");
static IIO_CONST_ATTR(in_concentration_voc_scale, "0.00000000436681223");

in drivers/iio/chemical/vz89x.c (I wonder why it goes through an IIO
const attributes instead than using the channel scale).

Another question is where the standard IIO units are defined for each
channel type ?

Thanks
   j

>
> Thanks,
>
> Matt
>
> > +               .ext_info = sunrise_concentration_ext_info,
> > +               .scan_index = 0,
> > +               .scan_type =  {
> > +                       .sign = 's',
> > +                       .realbits = 16,
> > +                       .storagebits = 16,
> > +                       .endianness = IIO_CPU,
> > +               },
> > +       },
> > +       {
> > +               .type = IIO_TEMP,
> > +               .info_mask_separate =  BIT(IIO_CHAN_INFO_RAW) |
> > +                                      BIT(IIO_CHAN_INFO_SCALE),
> > +               .scan_index = 1,
> > +               .scan_type =  {
> > +                       .sign = 's',
> > +                       .realbits = 16,
> > +                       .storagebits = 16,
> > +                       .endianness = IIO_CPU,
> > +               },
> > +       },
> > +};
> > +
> > +static int sunrise_read_raw(struct iio_dev *iio_dev,
> > +                           const struct iio_chan_spec *chan,
> > +                           int *val, int *val2, long mask)
> > +{
> > +       struct sunrise_dev *sunrise = iio_priv(iio_dev);
> > +       u16 value;
> > +       int ret;
> > +
> > +       switch (mask) {
> > +       case IIO_CHAN_INFO_RAW:
> > +               switch (chan->type) {
> > +               case IIO_CONCENTRATION:
> > +                       mutex_lock(&sunrise->lock);
> > +                       ret = sunrise_read_word(sunrise, SUNRISE_CO2_FILTERED_COMP_REG,
> > +                                               &value);
> > +                       *val = value;
> > +                       mutex_unlock(&sunrise->lock);
> > +
> > +                       if (ret)
> > +                               return ret;
> > +
> > +                       return IIO_VAL_INT;
> > +
> > +               case IIO_TEMP:
> > +                       mutex_lock(&sunrise->lock);
> > +                       ret = sunrise_read_word(sunrise, SUNRISE_CHIP_TEMPERATURE_REG,
> > +                                               &value);
> > +                       *val = value;
> > +                       mutex_unlock(&sunrise->lock);
> > +
> > +                       if (ret)
> > +                               return ret;
> > +
> > +                       return IIO_VAL_INT;
> > +
> > +               default:
> > +                       return -EINVAL;
> > +               }
> > +
> > +       case IIO_CHAN_INFO_SCALE:
> > +               /* x10 to comply with IIO scale (1/1000 degress celsius). */
> > +               *val = 10;
> > +               return IIO_VAL_INT;
> > +
> > +       default:
> > +               return -EINVAL;
> > +       }
> > +}
> > +
> > +static const struct iio_info sunrise_info = {
> > +       .read_raw = sunrise_read_raw,
> > +};
> > +
> > +static struct regmap_config sunrise_regmap_config = {
> > +       .reg_bits = 8,
> > +       .val_bits = 8,
> > +       /*
> > +        * Access to the i2c bus is locked by the driver to preserve the
> > +        * 'wakeup' session.
> > +        */
> > +       .disable_locking = true,
> > +};
> > +
> > +static int sunrise_probe(struct i2c_client *client)
> > +{
> > +       struct sunrise_dev *sunrise;
> > +       struct iio_dev *iio_dev;
> > +
> > +       iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*sunrise));
> > +       if (!iio_dev)
> > +               return -ENOMEM;
> > +
> > +       sunrise = iio_priv(iio_dev);
> > +       sunrise->client = client;
> > +       mutex_init(&sunrise->lock);
> > +       mutex_init(&sunrise->wakeup_lock);
> > +
> > +       sunrise->regmap = devm_regmap_init_i2c(client, &sunrise_regmap_config);
> > +       if (IS_ERR(sunrise->regmap)) {
> > +               dev_err(&client->dev, "Failed to initialize regmap\n");
> > +               return PTR_ERR(sunrise->regmap);
> > +       }
> > +
> > +       iio_dev->info = &sunrise_info;
> > +       iio_dev->name = DRIVER_NAME;
> > +       iio_dev->channels = sunrise_channels;
> > +       iio_dev->num_channels = ARRAY_SIZE(sunrise_channels);
> > +       iio_dev->modes = INDIO_DIRECT_MODE;
> > +
> > +       return devm_iio_device_register(&client->dev, iio_dev);
> > +}
> > +
> > +static const struct of_device_id sunrise_of_match[] = {
> > +       { .compatible = "senseair,sunrise-006-0-0007" },
> > +       {}
> > +};
> > +MODULE_DEVICE_TABLE(of, sunrise_of_match);
> > +
> > +static struct i2c_driver sunrise_driver = {
> > +       .driver = {
> > +               .name = DRIVER_NAME,
> > +               .of_match_table = sunrise_of_match,
> > +       },
> > +       .probe_new = sunrise_probe,
> > +};
> > +module_i2c_driver(sunrise_driver);
> > +
> > +MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>");
> > +MODULE_DESCRIPTION("Senseair Sunrise 006-0-0007 CO2 sensor IIO driver");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 2.32.0
> >

Re: [PATCH v4 2/3] iio: chemical: Add Senseair Sunrise 006-0-007 driver

[Jonathan Cameron]

On Wed, 8 Sep 2021 14:48:36 +0200
Jacopo Mondi <jacopo@jmondi.org> wrote:

> Hi Matt,
> 
> On Sun, Sep 05, 2021 at 02:10:43PM -0700, Matt Ranostay wrote:
> > On Fri, Sep 3, 2021 at 7:48 AM Jacopo Mondi <jacopo@jmondi.org> wrote:  
> > >
> > > Add support for the Senseair Sunrise 006-0-0007 driver through the
> > > IIO subsystem.
> > >
> > > Datasheet: https://rmtplusstoragesenseair.blob.core.windows.net/docs/Dev/publicerat/TDE5531.pdf
> > > Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
> > > ---
> > >  MAINTAINERS                        |   6 +
> > >  drivers/iio/chemical/Kconfig       |  10 +
> > >  drivers/iio/chemical/Makefile      |   1 +
> > >  drivers/iio/chemical/sunrise_co2.c | 487 +++++++++++++++++++++++++++++
> > >  4 files changed, 504 insertions(+)
> > >  create mode 100644 drivers/iio/chemical/sunrise_co2.c
> > >
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > index d7b4f32875a9..a8b859297e9e 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -16723,6 +16723,12 @@ S:     Maintained
> > >  F:     drivers/misc/phantom.c
> > >  F:     include/uapi/linux/phantom.h
> > >
> > > +SENSEAIR SUNRISE 006-0-0007
> > > +M:     Jacopo Mondi <jacopo@jmondi.org>
> > > +S:     Maintained
> > > +F:     Documentation/devicetree/bindings/iio/chemical/senseair,sunrise.yaml
> > > +F:     drivers/iio/chemical/sunrise_co2.c
> > > +
> > >  SENSIRION SCD30 CARBON DIOXIDE SENSOR DRIVER
> > >  M:     Tomasz Duszynski <tomasz.duszynski@octakon.com>
> > >  S:     Maintained
> > > diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
> > > index a4920646e9be..5155ab2caed4 100644
> > > --- a/drivers/iio/chemical/Kconfig
> > > +++ b/drivers/iio/chemical/Kconfig
> > > @@ -159,6 +159,16 @@ config SPS30_SERIAL
> > >           To compile this driver as a module, choose M here: the module will
> > >           be called sps30_serial.
> > >
> > > +config SENSEAIR_SUNRISE_CO2
> > > +       tristate "Senseair Sunrise 006-0-0007 CO2 sensor"
> > > +       select REGMAP_I2C
> > > +       help
> > > +         Say yes here to build support for Senseair Sunrise 006-0-0007 CO2
> > > +         sensor.
> > > +
> > > +         To compile this driver as a module, choose M here: the
> > > +         module will be called sunrise_co2.
> > > +
> > >  config VZ89X
> > >         tristate "SGX Sensortech MiCS VZ89X VOC sensor"
> > >         depends on I2C
> > > diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
> > > index 4898690cc155..61e8749a84f3 100644
> > > --- a/drivers/iio/chemical/Makefile
> > > +++ b/drivers/iio/chemical/Makefile
> > > @@ -15,6 +15,7 @@ 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-$(CONFIG_SENSEAIR_SUNRISE_CO2) += sunrise_co2.o
> > >  obj-$(CONFIG_SENSIRION_SGP30)  += sgp30.o
> > >  obj-$(CONFIG_SPS30) += sps30.o
> > >  obj-$(CONFIG_SPS30_I2C) += sps30_i2c.o
> > > diff --git a/drivers/iio/chemical/sunrise_co2.c b/drivers/iio/chemical/sunrise_co2.c
> > > new file mode 100644
> > > index 000000000000..cf15cdbaa24a
> > > --- /dev/null
> > > +++ b/drivers/iio/chemical/sunrise_co2.c
> > > @@ -0,0 +1,487 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * Senseair Sunrise 006-0-0007 CO2 sensor driver.
> > > + *
> > > + * Copyright (C) 2021 Jacopo Mondi
> > > + *
> > > + * List of features not yet supported by the driver:
> > > + * - controllable EN pin
> > > + * - single-shot operations using the nDRY pin.
> > > + * - ABC/target calibration
> > > + */
> > > +
> > > +#include <linux/bitops.h>
> > > +#include <linux/i2c.h>
> > > +#include <linux/kernel.h>
> > > +#include <linux/mod_devicetable.h>
> > > +#include <linux/module.h>
> > > +#include <linux/mutex.h>
> > > +#include <linux/regmap.h>
> > > +#include <linux/time64.h>
> > > +
> > > +#include <linux/iio/iio.h>
> > > +
> > > +#define DRIVER_NAME "sunrise_co2"
> > > +
> > > +#define SUNRISE_ERROR_STATUS_REG               0x00
> > > +#define SUNRISE_CO2_FILTERED_COMP_REG          0x06
> > > +#define SUNRISE_CHIP_TEMPERATURE_REG           0x08
> > > +#define SUNRISE_CALIBRATION_STATUS_REG         0x81
> > > +#define SUNRISE_CALIBRATION_COMMAND_REG                0x82
> > > +#define SUNRISE_CALIBRATION_FACTORY_CMD                0x7c02
> > > +#define SUNRISE_CALIBRATION_BACKGROUND_CMD     0x7c06
> > > +/*
> > > + * The calibration timeout is not characterized in the datasheet.
> > > + * Use 30 seconds as a reasonable upper limit.
> > > + */
> > > +#define SUNRISE_CALIBRATION_TIMEOUT_US         (30 * USEC_PER_SEC)
> > > +
> > > +struct sunrise_dev {
> > > +       struct i2c_client *client;
> > > +       struct regmap *regmap;
> > > +       /* Protects access to IIO attributes. */
> > > +       struct mutex lock;
> > > +       /* Protects chip's wakup session. */
> > > +       struct mutex wakeup_lock;
> > > +};
> > > +
> > > +static void sunrise_wakeup(struct sunrise_dev *sunrise)
> > > +{
> > > +       struct i2c_client *client = sunrise->client;
> > > +
> > > +       /*
> > > +        * Wake up sensor by sending sensor address: START, sensor address,
> > > +        * STOP. Sensor will not ACK this byte.
> > > +        *
> > > +        * The chip returns in low power state after 15msec without
> > > +        * communications or after a complete read/write sequence.
> > > +        */
> > > +       i2c_smbus_xfer(client->adapter, client->addr, I2C_M_IGNORE_NAK,
> > > +                      I2C_SMBUS_WRITE, 0, I2C_SMBUS_QUICK, NULL);
> > > +}
> > > +
> > > +static int sunrise_read_byte(struct sunrise_dev *sunrise, u8 reg)
> > > +{
> > > +       unsigned int val;
> > > +       int ret;
> > > +
> > > +       /*
> > > +        * Lock the 'wakeup' session.
> > > +        *
> > > +        * If another read/write call sneaks in between the wakeup message
> > > +        * and the i2c transaction, the chip goes back in sleep state.
> > > +        */
> > > +       mutex_lock(&sunrise->wakeup_lock);
> > > +       sunrise_wakeup(sunrise);
> > > +       ret = regmap_read(sunrise->regmap, reg, &val);
> > > +       mutex_unlock(&sunrise->wakeup_lock);
> > > +       if (ret) {
> > > +               dev_err(&sunrise->client->dev,
> > > +                       "Read byte failed: reg 0x%2x (%d)\n", reg, ret);
> > > +               return ret;
> > > +       }
> > > +
> > > +       return val;
> > > +}
> > > +
> > > +static int sunrise_read_word(struct sunrise_dev *sunrise, u8 reg, u16 *val)
> > > +{
> > > +       __be16 be_val;
> > > +       int ret;
> > > +
> > > +       mutex_lock(&sunrise->wakeup_lock);
> > > +       sunrise_wakeup(sunrise);
> > > +       ret = regmap_bulk_read(sunrise->regmap, reg, &be_val, 2);
> > > +       mutex_unlock(&sunrise->wakeup_lock);
> > > +       if (ret) {
> > > +               dev_err(&sunrise->client->dev,
> > > +                       "Read word failed: reg 0x%2x (%d)\n", reg, ret);
> > > +               return ret;
> > > +       }
> > > +
> > > +       *val = be16_to_cpu(be_val);
> > > +
> > > +       return 0;
> > > +}
> > > +
> > > +static int sunrise_write_byte(struct sunrise_dev *sunrise, u8 reg, u8 val)
> > > +{
> > > +       int ret;
> > > +
> > > +       mutex_lock(&sunrise->wakeup_lock);
> > > +       sunrise_wakeup(sunrise);
> > > +       ret = regmap_write(sunrise->regmap, reg, val);
> > > +       mutex_unlock(&sunrise->wakeup_lock);
> > > +       if (ret) {
> > > +               dev_err(&sunrise->client->dev,
> > > +                       "Write byte failed: reg 0x%2x (%d)\n", reg, ret);
> > > +               return ret;
> > > +       }
> > > +
> > > +       return 0;
> > > +}
> > > +
> > > +static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data)
> > > +{
> > > +       __be16 be_data = cpu_to_be16(data);
> > > +       int ret;
> > > +
> > > +       mutex_lock(&sunrise->wakeup_lock);
> > > +       sunrise_wakeup(sunrise);
> > > +       ret = regmap_bulk_write(sunrise->regmap, reg, &be_data, 2);
> > > +       mutex_unlock(&sunrise->wakeup_lock);
> > > +       if (ret) {
> > > +               dev_err(&sunrise->client->dev,
> > > +                       "Write word failed: reg 0x%2x (%d)\n", reg, ret);
> > > +               return ret;
> > > +       }
> > > +
> > > +       return 0;
> > > +}
> > > +
> > > +/* Trigger a calibration cycle. */
> > > +
> > > +enum {
> > > +       SUNRISE_CALIBRATION_FACTORY,
> > > +       SUNRISE_CALIBRATION_BACKGROUND,
> > > +};
> > > +
> > > +static const struct sunrise_calib_data {
> > > +       u16 cmd;
> > > +       u8 bit;
> > > +       const char * const name;
> > > +} calib_data[] = {
> > > +       [SUNRISE_CALIBRATION_FACTORY] = {
> > > +               SUNRISE_CALIBRATION_FACTORY_CMD,
> > > +               BIT(2),
> > > +               "factory_calibration",
> > > +       },
> > > +       [SUNRISE_CALIBRATION_BACKGROUND] = {
> > > +               SUNRISE_CALIBRATION_BACKGROUND_CMD,
> > > +               BIT(5),
> > > +               "background_calibration",
> > > +       },
> > > +};
> > > +
> > > +static int sunrise_calibrate(struct sunrise_dev *sunrise,
> > > +                            const struct sunrise_calib_data *data)
> > > +{
> > > +       unsigned int status;
> > > +       int ret;
> > > +
> > > +       /* Reset the calibration status reg. */
> > > +       ret = sunrise_write_byte(sunrise, SUNRISE_CALIBRATION_STATUS_REG, 0x00);
> > > +       if (ret)
> > > +               return ret;
> > > +
> > > +       /* Write a calibration command and poll the calibration status bit. */
> > > +       ret = sunrise_write_word(sunrise, SUNRISE_CALIBRATION_COMMAND_REG,
> > > +                                data->cmd);
> > > +       if (ret)
> > > +               return ret;
> > > +
> > > +       dev_dbg(&sunrise->client->dev, "%s in progress\n", data->name);
> > > +
> > > +       /*
> > > +        * Calibration takes several seconds, so the sleep time between reads
> > > +        * can be pretty relaxed.
> > > +        */
> > > +       return read_poll_timeout(sunrise_read_byte, status,
> > > +                                status & data->bit, 200000,
> > > +                                SUNRISE_CALIBRATION_TIMEOUT_US, false,
> > > +                                sunrise, SUNRISE_CALIBRATION_STATUS_REG);
> > > +}
> > > +
> > > +static ssize_t sunrise_cal_read(const char *buf, size_t len)
> > > +{
> > > +       bool enable;
> > > +       int ret;
> > > +
> > > +       ret = kstrtobool(buf, &enable);
> > > +       if (ret)
> > > +               return ret;
> > > +
> > > +       if (!enable)
> > > +               return len;
> > > +
> > > +       return 0;
> > > +}
> > > +
> > > +static ssize_t sunrise_cal_factory_write(struct iio_dev *iiodev,
> > > +                                        uintptr_t private,
> > > +                                        const struct iio_chan_spec *chan,
> > > +                                        const char *buf, size_t len)
> > > +{
> > > +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> > > +       int ret;
> > > +
> > > +       mutex_lock(&sunrise->lock);
> > > +       ret = sunrise_cal_read(buf, len);
> > > +       if (ret) {
> > > +               mutex_unlock(&sunrise->lock);
> > > +               return ret;
> > > +       }
> > > +
> > > +       ret = sunrise_calibrate(sunrise,
> > > +                               &calib_data[SUNRISE_CALIBRATION_FACTORY]);
> > > +       mutex_unlock(&sunrise->lock);
> > > +       if (ret)
> > > +               return ret;
> > > +
> > > +       return len;
> > > +}
> > > +
> > > +static ssize_t sunrise_cal_background_write(struct iio_dev *iiodev,
> > > +                                           uintptr_t private,
> > > +                                           const struct iio_chan_spec *chan,
> > > +                                           const char *buf, size_t len)
> > > +{
> > > +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> > > +       int ret;
> > > +
> > > +       mutex_lock(&sunrise->lock);
> > > +       ret = sunrise_cal_read(buf, len);
> > > +       if (ret) {
> > > +               mutex_unlock(&sunrise->lock);
> > > +               return ret;
> > > +       }
> > > +
> > > +       ret = sunrise_calibrate(sunrise,
> > > +                               &calib_data[SUNRISE_CALIBRATION_BACKGROUND]);
> > > +       mutex_unlock(&sunrise->lock);
> > > +       if (ret)
> > > +               return ret;
> > > +
> > > +       return len;
> > > +}
> > > +
> > > + /* Enumerate and retrieve the chip error status. */
> > > +enum {
> > > +       SUNRISE_ERROR_FATAL,
> > > +       SUNRISE_ERROR_I2C,
> > > +       SUNRISE_ERROR_ALGORITHM,
> > > +       SUNRISE_ERROR_CALIBRATION,
> > > +       SUNRISE_ERROR_SELF_DIAGNOSTIC,
> > > +       SUNRISE_ERROR_OUT_OF_RANGE,
> > > +       SUNRISE_ERROR_MEMORY,
> > > +       SUNRISE_ERROR_NO_MEASUREMENT,
> > > +       SUNRISE_ERROR_LOW_VOLTAGE,
> > > +       SUNRISE_ERROR_MEASUREMENT_TIMEOUT,
> > > +};
> > > +
> > > +static const char * const sunrise_error_statuses[] = {
> > > +       [SUNRISE_ERROR_FATAL] = "error_fatal",
> > > +       [SUNRISE_ERROR_I2C] = "error_i2c",
> > > +       [SUNRISE_ERROR_ALGORITHM] = "error_algorithm",
> > > +       [SUNRISE_ERROR_CALIBRATION] = "error_calibration",
> > > +       [SUNRISE_ERROR_SELF_DIAGNOSTIC] = "error_self_diagnostic",
> > > +       [SUNRISE_ERROR_OUT_OF_RANGE] = "error_out_of_range",
> > > +       [SUNRISE_ERROR_MEMORY] = "error_memory",
> > > +       [SUNRISE_ERROR_NO_MEASUREMENT] = "error_no_measurement",
> > > +       [SUNRISE_ERROR_LOW_VOLTAGE] = "error_low_voltage",
> > > +       [SUNRISE_ERROR_MEASUREMENT_TIMEOUT] = "error_measurement_timeout",
> > > +};
> > > +
> > > +static const struct iio_enum sunrise_error_statuses_enum = {
> > > +       .items = sunrise_error_statuses,
> > > +       .num_items = ARRAY_SIZE(sunrise_error_statuses),
> > > +};
> > > +
> > > +static ssize_t sunrise_error_status_read(struct iio_dev *iiodev,
> > > +                                        uintptr_t private,
> > > +                                        const struct iio_chan_spec *chan,
> > > +                                        char *buf)
> > > +{
> > > +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> > > +       unsigned long errors;
> > > +       ssize_t len = 0;
> > > +       u16 value;
> > > +       int ret;
> > > +       u8 i;
> > > +
> > > +       mutex_lock(&sunrise->lock);
> > > +       ret = sunrise_read_word(sunrise, SUNRISE_ERROR_STATUS_REG, &value);
> > > +       if (ret) {
> > > +               mutex_unlock(&sunrise->lock);
> > > +               return -EINVAL;
> > > +       }
> > > +
> > > +       errors = value;
> > > +       for_each_set_bit(i, &errors, ARRAY_SIZE(sunrise_error_statuses))
> > > +               len += sysfs_emit_at(buf, len, "%s ", sunrise_error_statuses[i]);
> > > +
> > > +       if (len)
> > > +               buf[len - 1] = '\n';
> > > +
> > > +       mutex_unlock(&sunrise->lock);
> > > +
> > > +       return len;
> > > +}
> > > +
> > > +static const struct iio_chan_spec_ext_info sunrise_concentration_ext_info[] = {
> > > +       /* Calibration triggers. */
> > > +       {
> > > +               .name = "calibration_factory",
> > > +               .write = sunrise_cal_factory_write,
> > > +               .shared = IIO_SEPARATE,
> > > +       },
> > > +       {
> > > +               .name = "calibration_background",
> > > +               .write = sunrise_cal_background_write,
> > > +               .shared = IIO_SEPARATE,
> > > +       },
> > > +
> > > +       /* Error statuses. */
> > > +       {
> > > +               .name = "error_status",
> > > +               .read = sunrise_error_status_read,
> > > +               .shared = IIO_SHARED_BY_ALL,
> > > +       },
> > > +       {
> > > +               .name = "error_status_available",
> > > +               .shared = IIO_SHARED_BY_ALL,
> > > +               .read = iio_enum_available_read,
> > > +               .private = (uintptr_t)&sunrise_error_statuses_enum,
> > > +       },
> > > +       {}
> > > +};
> > > +
> > > +static const struct iio_chan_spec sunrise_channels[] = {
> > > +       {
> > > +               .type = IIO_CONCENTRATION,
> > > +               .modified = 1,
> > > +               .channel2 = IIO_MOD_CO2,
> > > +               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),  
> >
> > Why isn't there a IIO_CHAN_INFO_SCALE for the CO2 channel?  Raw units
> > between different CO2 sensors aren't always in ppm  
> 
> Good point, I should add one. The reson I didn't do so is that
> Documentation/ABI/testing/sysfs-bus-iio doesn't report any
> in_concentration_co2_scale attribute. Should it be added ?

yes.  We don't have any automated testing on this yet so I don't always
catch ABI that isn't documented if it is 'standard' in the sense that
it is built by the core.  Good to add it thourgh.

> 
> Although I see this:
> 
> static IIO_CONST_ATTR(in_concentration_co2_scale, "0.00000698689");
> static IIO_CONST_ATTR(in_concentration_voc_scale, "0.00000000436681223");
> 
> in drivers/iio/chemical/vz89x.c (I wonder why it goes through an IIO
> const attributes instead than using the channel scale).
> 
> Another question is where the standard IIO units are defined for each
> channel type ?

Should be in sysfs-bus-iio as above.  Usually in the relevant _raw
description.

Might be missing though for some unit types. If they are we should fix
it!

Jonathan
> 
> Thanks
>    j
> 
> >
> > Thanks,
> >
> > Matt
> >  
> > > +               .ext_info = sunrise_concentration_ext_info,
> > > +               .scan_index = 0,
> > > +               .scan_type =  {
> > > +                       .sign = 's',
> > > +                       .realbits = 16,
> > > +                       .storagebits = 16,
> > > +                       .endianness = IIO_CPU,
> > > +               },
> > > +       },
> > > +       {
> > > +               .type = IIO_TEMP,
> > > +               .info_mask_separate =  BIT(IIO_CHAN_INFO_RAW) |
> > > +                                      BIT(IIO_CHAN_INFO_SCALE),
> > > +               .scan_index = 1,
> > > +               .scan_type =  {
> > > +                       .sign = 's',
> > > +                       .realbits = 16,
> > > +                       .storagebits = 16,
> > > +                       .endianness = IIO_CPU,
> > > +               },
> > > +       },
> > > +};
> > > +
> > > +static int sunrise_read_raw(struct iio_dev *iio_dev,
> > > +                           const struct iio_chan_spec *chan,
> > > +                           int *val, int *val2, long mask)
> > > +{
> > > +       struct sunrise_dev *sunrise = iio_priv(iio_dev);
> > > +       u16 value;
> > > +       int ret;
> > > +
> > > +       switch (mask) {
> > > +       case IIO_CHAN_INFO_RAW:
> > > +               switch (chan->type) {
> > > +               case IIO_CONCENTRATION:
> > > +                       mutex_lock(&sunrise->lock);
> > > +                       ret = sunrise_read_word(sunrise, SUNRISE_CO2_FILTERED_COMP_REG,
> > > +                                               &value);
> > > +                       *val = value;
> > > +                       mutex_unlock(&sunrise->lock);
> > > +
> > > +                       if (ret)
> > > +                               return ret;
> > > +
> > > +                       return IIO_VAL_INT;
> > > +
> > > +               case IIO_TEMP:
> > > +                       mutex_lock(&sunrise->lock);
> > > +                       ret = sunrise_read_word(sunrise, SUNRISE_CHIP_TEMPERATURE_REG,
> > > +                                               &value);
> > > +                       *val = value;
> > > +                       mutex_unlock(&sunrise->lock);
> > > +
> > > +                       if (ret)
> > > +                               return ret;
> > > +
> > > +                       return IIO_VAL_INT;
> > > +
> > > +               default:
> > > +                       return -EINVAL;
> > > +               }
> > > +
> > > +       case IIO_CHAN_INFO_SCALE:
> > > +               /* x10 to comply with IIO scale (1/1000 degress celsius). */
> > > +               *val = 10;
> > > +               return IIO_VAL_INT;
> > > +
> > > +       default:
> > > +               return -EINVAL;
> > > +       }
> > > +}
> > > +
> > > +static const struct iio_info sunrise_info = {
> > > +       .read_raw = sunrise_read_raw,
> > > +};
> > > +
> > > +static struct regmap_config sunrise_regmap_config = {
> > > +       .reg_bits = 8,
> > > +       .val_bits = 8,
> > > +       /*
> > > +        * Access to the i2c bus is locked by the driver to preserve the
> > > +        * 'wakeup' session.
> > > +        */
> > > +       .disable_locking = true,
> > > +};
> > > +
> > > +static int sunrise_probe(struct i2c_client *client)
> > > +{
> > > +       struct sunrise_dev *sunrise;
> > > +       struct iio_dev *iio_dev;
> > > +
> > > +       iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*sunrise));
> > > +       if (!iio_dev)
> > > +               return -ENOMEM;
> > > +
> > > +       sunrise = iio_priv(iio_dev);
> > > +       sunrise->client = client;
> > > +       mutex_init(&sunrise->lock);
> > > +       mutex_init(&sunrise->wakeup_lock);
> > > +
> > > +       sunrise->regmap = devm_regmap_init_i2c(client, &sunrise_regmap_config);
> > > +       if (IS_ERR(sunrise->regmap)) {
> > > +               dev_err(&client->dev, "Failed to initialize regmap\n");
> > > +               return PTR_ERR(sunrise->regmap);
> > > +       }
> > > +
> > > +       iio_dev->info = &sunrise_info;
> > > +       iio_dev->name = DRIVER_NAME;
> > > +       iio_dev->channels = sunrise_channels;
> > > +       iio_dev->num_channels = ARRAY_SIZE(sunrise_channels);
> > > +       iio_dev->modes = INDIO_DIRECT_MODE;
> > > +
> > > +       return devm_iio_device_register(&client->dev, iio_dev);
> > > +}
> > > +
> > > +static const struct of_device_id sunrise_of_match[] = {
> > > +       { .compatible = "senseair,sunrise-006-0-0007" },
> > > +       {}
> > > +};
> > > +MODULE_DEVICE_TABLE(of, sunrise_of_match);
> > > +
> > > +static struct i2c_driver sunrise_driver = {
> > > +       .driver = {
> > > +               .name = DRIVER_NAME,
> > > +               .of_match_table = sunrise_of_match,
> > > +       },
> > > +       .probe_new = sunrise_probe,
> > > +};
> > > +module_i2c_driver(sunrise_driver);
> > > +
> > > +MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>");
> > > +MODULE_DESCRIPTION("Senseair Sunrise 006-0-0007 CO2 sensor IIO driver");
> > > +MODULE_LICENSE("GPL v2");
> > > --
> > > 2.32.0
> > >  

Re: [PATCH v4 2/3] iio: chemical: Add Senseair Sunrise 006-0-007 driver

[Jacopo Mondi]

Hi Jonathan,

On Wed, Sep 08, 2021 at 05:56:34PM +0100, Jonathan Cameron wrote:
> On Wed, 8 Sep 2021 14:48:36 +0200
> Jacopo Mondi <jacopo@jmondi.org> wrote:
>
> > Hi Matt,
> >
> > On Sun, Sep 05, 2021 at 02:10:43PM -0700, Matt Ranostay wrote:
> > > On Fri, Sep 3, 2021 at 7:48 AM Jacopo Mondi <jacopo@jmondi.org> wrote:
> > > >
> > > > Add support for the Senseair Sunrise 006-0-0007 driver through the
> > > > IIO subsystem.
> > > >
> > > > Datasheet: https://rmtplusstoragesenseair.blob.core.windows.net/docs/Dev/publicerat/TDE5531.pdf
> > > > Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
> > > > ---
> > > >  MAINTAINERS                        |   6 +
> > > >  drivers/iio/chemical/Kconfig       |  10 +
> > > >  drivers/iio/chemical/Makefile      |   1 +
> > > >  drivers/iio/chemical/sunrise_co2.c | 487 +++++++++++++++++++++++++++++
> > > >  4 files changed, 504 insertions(+)
> > > >  create mode 100644 drivers/iio/chemical/sunrise_co2.c
> > > >
> > > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > > index d7b4f32875a9..a8b859297e9e 100644
> > > > --- a/MAINTAINERS
> > > > +++ b/MAINTAINERS
> > > > @@ -16723,6 +16723,12 @@ S:     Maintained
> > > >  F:     drivers/misc/phantom.c
> > > >  F:     include/uapi/linux/phantom.h
> > > >
> > > > +SENSEAIR SUNRISE 006-0-0007
> > > > +M:     Jacopo Mondi <jacopo@jmondi.org>
> > > > +S:     Maintained
> > > > +F:     Documentation/devicetree/bindings/iio/chemical/senseair,sunrise.yaml
> > > > +F:     drivers/iio/chemical/sunrise_co2.c
> > > > +
> > > >  SENSIRION SCD30 CARBON DIOXIDE SENSOR DRIVER
> > > >  M:     Tomasz Duszynski <tomasz.duszynski@octakon.com>
> > > >  S:     Maintained
> > > > diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
> > > > index a4920646e9be..5155ab2caed4 100644
> > > > --- a/drivers/iio/chemical/Kconfig
> > > > +++ b/drivers/iio/chemical/Kconfig
> > > > @@ -159,6 +159,16 @@ config SPS30_SERIAL
> > > >           To compile this driver as a module, choose M here: the module will
> > > >           be called sps30_serial.
> > > >
> > > > +config SENSEAIR_SUNRISE_CO2
> > > > +       tristate "Senseair Sunrise 006-0-0007 CO2 sensor"
> > > > +       select REGMAP_I2C
> > > > +       help
> > > > +         Say yes here to build support for Senseair Sunrise 006-0-0007 CO2
> > > > +         sensor.
> > > > +
> > > > +         To compile this driver as a module, choose M here: the
> > > > +         module will be called sunrise_co2.
> > > > +
> > > >  config VZ89X
> > > >         tristate "SGX Sensortech MiCS VZ89X VOC sensor"
> > > >         depends on I2C
> > > > diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
> > > > index 4898690cc155..61e8749a84f3 100644
> > > > --- a/drivers/iio/chemical/Makefile
> > > > +++ b/drivers/iio/chemical/Makefile
> > > > @@ -15,6 +15,7 @@ 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-$(CONFIG_SENSEAIR_SUNRISE_CO2) += sunrise_co2.o
> > > >  obj-$(CONFIG_SENSIRION_SGP30)  += sgp30.o
> > > >  obj-$(CONFIG_SPS30) += sps30.o
> > > >  obj-$(CONFIG_SPS30_I2C) += sps30_i2c.o
> > > > diff --git a/drivers/iio/chemical/sunrise_co2.c b/drivers/iio/chemical/sunrise_co2.c
> > > > new file mode 100644
> > > > index 000000000000..cf15cdbaa24a
> > > > --- /dev/null
> > > > +++ b/drivers/iio/chemical/sunrise_co2.c
> > > > @@ -0,0 +1,487 @@
> > > > +// SPDX-License-Identifier: GPL-2.0
> > > > +/*
> > > > + * Senseair Sunrise 006-0-0007 CO2 sensor driver.
> > > > + *
> > > > + * Copyright (C) 2021 Jacopo Mondi
> > > > + *
> > > > + * List of features not yet supported by the driver:
> > > > + * - controllable EN pin
> > > > + * - single-shot operations using the nDRY pin.
> > > > + * - ABC/target calibration
> > > > + */
> > > > +
> > > > +#include <linux/bitops.h>
> > > > +#include <linux/i2c.h>
> > > > +#include <linux/kernel.h>
> > > > +#include <linux/mod_devicetable.h>
> > > > +#include <linux/module.h>
> > > > +#include <linux/mutex.h>
> > > > +#include <linux/regmap.h>
> > > > +#include <linux/time64.h>
> > > > +
> > > > +#include <linux/iio/iio.h>
> > > > +
> > > > +#define DRIVER_NAME "sunrise_co2"
> > > > +
> > > > +#define SUNRISE_ERROR_STATUS_REG               0x00
> > > > +#define SUNRISE_CO2_FILTERED_COMP_REG          0x06
> > > > +#define SUNRISE_CHIP_TEMPERATURE_REG           0x08
> > > > +#define SUNRISE_CALIBRATION_STATUS_REG         0x81
> > > > +#define SUNRISE_CALIBRATION_COMMAND_REG                0x82
> > > > +#define SUNRISE_CALIBRATION_FACTORY_CMD                0x7c02
> > > > +#define SUNRISE_CALIBRATION_BACKGROUND_CMD     0x7c06
> > > > +/*
> > > > + * The calibration timeout is not characterized in the datasheet.
> > > > + * Use 30 seconds as a reasonable upper limit.
> > > > + */
> > > > +#define SUNRISE_CALIBRATION_TIMEOUT_US         (30 * USEC_PER_SEC)
> > > > +
> > > > +struct sunrise_dev {
> > > > +       struct i2c_client *client;
> > > > +       struct regmap *regmap;
> > > > +       /* Protects access to IIO attributes. */
> > > > +       struct mutex lock;
> > > > +       /* Protects chip's wakup session. */
> > > > +       struct mutex wakeup_lock;
> > > > +};
> > > > +
> > > > +static void sunrise_wakeup(struct sunrise_dev *sunrise)
> > > > +{
> > > > +       struct i2c_client *client = sunrise->client;
> > > > +
> > > > +       /*
> > > > +        * Wake up sensor by sending sensor address: START, sensor address,
> > > > +        * STOP. Sensor will not ACK this byte.
> > > > +        *
> > > > +        * The chip returns in low power state after 15msec without
> > > > +        * communications or after a complete read/write sequence.
> > > > +        */
> > > > +       i2c_smbus_xfer(client->adapter, client->addr, I2C_M_IGNORE_NAK,
> > > > +                      I2C_SMBUS_WRITE, 0, I2C_SMBUS_QUICK, NULL);
> > > > +}
> > > > +
> > > > +static int sunrise_read_byte(struct sunrise_dev *sunrise, u8 reg)
> > > > +{
> > > > +       unsigned int val;
> > > > +       int ret;
> > > > +
> > > > +       /*
> > > > +        * Lock the 'wakeup' session.
> > > > +        *
> > > > +        * If another read/write call sneaks in between the wakeup message
> > > > +        * and the i2c transaction, the chip goes back in sleep state.
> > > > +        */
> > > > +       mutex_lock(&sunrise->wakeup_lock);
> > > > +       sunrise_wakeup(sunrise);
> > > > +       ret = regmap_read(sunrise->regmap, reg, &val);
> > > > +       mutex_unlock(&sunrise->wakeup_lock);
> > > > +       if (ret) {
> > > > +               dev_err(&sunrise->client->dev,
> > > > +                       "Read byte failed: reg 0x%2x (%d)\n", reg, ret);
> > > > +               return ret;
> > > > +       }
> > > > +
> > > > +       return val;
> > > > +}
> > > > +
> > > > +static int sunrise_read_word(struct sunrise_dev *sunrise, u8 reg, u16 *val)
> > > > +{
> > > > +       __be16 be_val;
> > > > +       int ret;
> > > > +
> > > > +       mutex_lock(&sunrise->wakeup_lock);
> > > > +       sunrise_wakeup(sunrise);
> > > > +       ret = regmap_bulk_read(sunrise->regmap, reg, &be_val, 2);
> > > > +       mutex_unlock(&sunrise->wakeup_lock);
> > > > +       if (ret) {
> > > > +               dev_err(&sunrise->client->dev,
> > > > +                       "Read word failed: reg 0x%2x (%d)\n", reg, ret);
> > > > +               return ret;
> > > > +       }
> > > > +
> > > > +       *val = be16_to_cpu(be_val);
> > > > +
> > > > +       return 0;
> > > > +}
> > > > +
> > > > +static int sunrise_write_byte(struct sunrise_dev *sunrise, u8 reg, u8 val)
> > > > +{
> > > > +       int ret;
> > > > +
> > > > +       mutex_lock(&sunrise->wakeup_lock);
> > > > +       sunrise_wakeup(sunrise);
> > > > +       ret = regmap_write(sunrise->regmap, reg, val);
> > > > +       mutex_unlock(&sunrise->wakeup_lock);
> > > > +       if (ret) {
> > > > +               dev_err(&sunrise->client->dev,
> > > > +                       "Write byte failed: reg 0x%2x (%d)\n", reg, ret);
> > > > +               return ret;
> > > > +       }
> > > > +
> > > > +       return 0;
> > > > +}
> > > > +
> > > > +static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data)
> > > > +{
> > > > +       __be16 be_data = cpu_to_be16(data);
> > > > +       int ret;
> > > > +
> > > > +       mutex_lock(&sunrise->wakeup_lock);
> > > > +       sunrise_wakeup(sunrise);
> > > > +       ret = regmap_bulk_write(sunrise->regmap, reg, &be_data, 2);
> > > > +       mutex_unlock(&sunrise->wakeup_lock);
> > > > +       if (ret) {
> > > > +               dev_err(&sunrise->client->dev,
> > > > +                       "Write word failed: reg 0x%2x (%d)\n", reg, ret);
> > > > +               return ret;
> > > > +       }
> > > > +
> > > > +       return 0;
> > > > +}
> > > > +
> > > > +/* Trigger a calibration cycle. */
> > > > +
> > > > +enum {
> > > > +       SUNRISE_CALIBRATION_FACTORY,
> > > > +       SUNRISE_CALIBRATION_BACKGROUND,
> > > > +};
> > > > +
> > > > +static const struct sunrise_calib_data {
> > > > +       u16 cmd;
> > > > +       u8 bit;
> > > > +       const char * const name;
> > > > +} calib_data[] = {
> > > > +       [SUNRISE_CALIBRATION_FACTORY] = {
> > > > +               SUNRISE_CALIBRATION_FACTORY_CMD,
> > > > +               BIT(2),
> > > > +               "factory_calibration",
> > > > +       },
> > > > +       [SUNRISE_CALIBRATION_BACKGROUND] = {
> > > > +               SUNRISE_CALIBRATION_BACKGROUND_CMD,
> > > > +               BIT(5),
> > > > +               "background_calibration",
> > > > +       },
> > > > +};
> > > > +
> > > > +static int sunrise_calibrate(struct sunrise_dev *sunrise,
> > > > +                            const struct sunrise_calib_data *data)
> > > > +{
> > > > +       unsigned int status;
> > > > +       int ret;
> > > > +
> > > > +       /* Reset the calibration status reg. */
> > > > +       ret = sunrise_write_byte(sunrise, SUNRISE_CALIBRATION_STATUS_REG, 0x00);
> > > > +       if (ret)
> > > > +               return ret;
> > > > +
> > > > +       /* Write a calibration command and poll the calibration status bit. */
> > > > +       ret = sunrise_write_word(sunrise, SUNRISE_CALIBRATION_COMMAND_REG,
> > > > +                                data->cmd);
> > > > +       if (ret)
> > > > +               return ret;
> > > > +
> > > > +       dev_dbg(&sunrise->client->dev, "%s in progress\n", data->name);
> > > > +
> > > > +       /*
> > > > +        * Calibration takes several seconds, so the sleep time between reads
> > > > +        * can be pretty relaxed.
> > > > +        */
> > > > +       return read_poll_timeout(sunrise_read_byte, status,
> > > > +                                status & data->bit, 200000,
> > > > +                                SUNRISE_CALIBRATION_TIMEOUT_US, false,
> > > > +                                sunrise, SUNRISE_CALIBRATION_STATUS_REG);
> > > > +}
> > > > +
> > > > +static ssize_t sunrise_cal_read(const char *buf, size_t len)
> > > > +{
> > > > +       bool enable;
> > > > +       int ret;
> > > > +
> > > > +       ret = kstrtobool(buf, &enable);
> > > > +       if (ret)
> > > > +               return ret;
> > > > +
> > > > +       if (!enable)
> > > > +               return len;
> > > > +
> > > > +       return 0;
> > > > +}
> > > > +
> > > > +static ssize_t sunrise_cal_factory_write(struct iio_dev *iiodev,
> > > > +                                        uintptr_t private,
> > > > +                                        const struct iio_chan_spec *chan,
> > > > +                                        const char *buf, size_t len)
> > > > +{
> > > > +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> > > > +       int ret;
> > > > +
> > > > +       mutex_lock(&sunrise->lock);
> > > > +       ret = sunrise_cal_read(buf, len);
> > > > +       if (ret) {
> > > > +               mutex_unlock(&sunrise->lock);
> > > > +               return ret;
> > > > +       }
> > > > +
> > > > +       ret = sunrise_calibrate(sunrise,
> > > > +                               &calib_data[SUNRISE_CALIBRATION_FACTORY]);
> > > > +       mutex_unlock(&sunrise->lock);
> > > > +       if (ret)
> > > > +               return ret;
> > > > +
> > > > +       return len;
> > > > +}
> > > > +
> > > > +static ssize_t sunrise_cal_background_write(struct iio_dev *iiodev,
> > > > +                                           uintptr_t private,
> > > > +                                           const struct iio_chan_spec *chan,
> > > > +                                           const char *buf, size_t len)
> > > > +{
> > > > +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> > > > +       int ret;
> > > > +
> > > > +       mutex_lock(&sunrise->lock);
> > > > +       ret = sunrise_cal_read(buf, len);
> > > > +       if (ret) {
> > > > +               mutex_unlock(&sunrise->lock);
> > > > +               return ret;
> > > > +       }
> > > > +
> > > > +       ret = sunrise_calibrate(sunrise,
> > > > +                               &calib_data[SUNRISE_CALIBRATION_BACKGROUND]);
> > > > +       mutex_unlock(&sunrise->lock);
> > > > +       if (ret)
> > > > +               return ret;
> > > > +
> > > > +       return len;
> > > > +}
> > > > +
> > > > + /* Enumerate and retrieve the chip error status. */
> > > > +enum {
> > > > +       SUNRISE_ERROR_FATAL,
> > > > +       SUNRISE_ERROR_I2C,
> > > > +       SUNRISE_ERROR_ALGORITHM,
> > > > +       SUNRISE_ERROR_CALIBRATION,
> > > > +       SUNRISE_ERROR_SELF_DIAGNOSTIC,
> > > > +       SUNRISE_ERROR_OUT_OF_RANGE,
> > > > +       SUNRISE_ERROR_MEMORY,
> > > > +       SUNRISE_ERROR_NO_MEASUREMENT,
> > > > +       SUNRISE_ERROR_LOW_VOLTAGE,
> > > > +       SUNRISE_ERROR_MEASUREMENT_TIMEOUT,
> > > > +};
> > > > +
> > > > +static const char * const sunrise_error_statuses[] = {
> > > > +       [SUNRISE_ERROR_FATAL] = "error_fatal",
> > > > +       [SUNRISE_ERROR_I2C] = "error_i2c",
> > > > +       [SUNRISE_ERROR_ALGORITHM] = "error_algorithm",
> > > > +       [SUNRISE_ERROR_CALIBRATION] = "error_calibration",
> > > > +       [SUNRISE_ERROR_SELF_DIAGNOSTIC] = "error_self_diagnostic",
> > > > +       [SUNRISE_ERROR_OUT_OF_RANGE] = "error_out_of_range",
> > > > +       [SUNRISE_ERROR_MEMORY] = "error_memory",
> > > > +       [SUNRISE_ERROR_NO_MEASUREMENT] = "error_no_measurement",
> > > > +       [SUNRISE_ERROR_LOW_VOLTAGE] = "error_low_voltage",
> > > > +       [SUNRISE_ERROR_MEASUREMENT_TIMEOUT] = "error_measurement_timeout",
> > > > +};
> > > > +
> > > > +static const struct iio_enum sunrise_error_statuses_enum = {
> > > > +       .items = sunrise_error_statuses,
> > > > +       .num_items = ARRAY_SIZE(sunrise_error_statuses),
> > > > +};
> > > > +
> > > > +static ssize_t sunrise_error_status_read(struct iio_dev *iiodev,
> > > > +                                        uintptr_t private,
> > > > +                                        const struct iio_chan_spec *chan,
> > > > +                                        char *buf)
> > > > +{
> > > > +       struct sunrise_dev *sunrise = iio_priv(iiodev);
> > > > +       unsigned long errors;
> > > > +       ssize_t len = 0;
> > > > +       u16 value;
> > > > +       int ret;
> > > > +       u8 i;
> > > > +
> > > > +       mutex_lock(&sunrise->lock);
> > > > +       ret = sunrise_read_word(sunrise, SUNRISE_ERROR_STATUS_REG, &value);
> > > > +       if (ret) {
> > > > +               mutex_unlock(&sunrise->lock);
> > > > +               return -EINVAL;
> > > > +       }
> > > > +
> > > > +       errors = value;
> > > > +       for_each_set_bit(i, &errors, ARRAY_SIZE(sunrise_error_statuses))
> > > > +               len += sysfs_emit_at(buf, len, "%s ", sunrise_error_statuses[i]);
> > > > +
> > > > +       if (len)
> > > > +               buf[len - 1] = '\n';
> > > > +
> > > > +       mutex_unlock(&sunrise->lock);
> > > > +
> > > > +       return len;
> > > > +}
> > > > +
> > > > +static const struct iio_chan_spec_ext_info sunrise_concentration_ext_info[] = {
> > > > +       /* Calibration triggers. */
> > > > +       {
> > > > +               .name = "calibration_factory",
> > > > +               .write = sunrise_cal_factory_write,
> > > > +               .shared = IIO_SEPARATE,
> > > > +       },
> > > > +       {
> > > > +               .name = "calibration_background",
> > > > +               .write = sunrise_cal_background_write,
> > > > +               .shared = IIO_SEPARATE,
> > > > +       },
> > > > +
> > > > +       /* Error statuses. */
> > > > +       {
> > > > +               .name = "error_status",
> > > > +               .read = sunrise_error_status_read,
> > > > +               .shared = IIO_SHARED_BY_ALL,
> > > > +       },
> > > > +       {
> > > > +               .name = "error_status_available",
> > > > +               .shared = IIO_SHARED_BY_ALL,
> > > > +               .read = iio_enum_available_read,
> > > > +               .private = (uintptr_t)&sunrise_error_statuses_enum,
> > > > +       },
> > > > +       {}
> > > > +};
> > > > +
> > > > +static const struct iio_chan_spec sunrise_channels[] = {
> > > > +       {
> > > > +               .type = IIO_CONCENTRATION,
> > > > +               .modified = 1,
> > > > +               .channel2 = IIO_MOD_CO2,
> > > > +               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > >
> > > Why isn't there a IIO_CHAN_INFO_SCALE for the CO2 channel?  Raw units
> > > between different CO2 sensors aren't always in ppm
> >
> > Good point, I should add one. The reson I didn't do so is that
> > Documentation/ABI/testing/sysfs-bus-iio doesn't report any
> > in_concentration_co2_scale attribute. Should it be added ?
>
> yes.  We don't have any automated testing on this yet so I don't always
> catch ABI that isn't documented if it is 'standard' in the sense that
> it is built by the core.  Good to add it thourgh.
>

Thanks, will add it to the list of _scale attributes as part of the
'standard' ones.

> >
> > Although I see this:
> >
> > static IIO_CONST_ATTR(in_concentration_co2_scale, "0.00000698689");
> > static IIO_CONST_ATTR(in_concentration_voc_scale, "0.00000000436681223");
> >
> > in drivers/iio/chemical/vz89x.c (I wonder why it goes through an IIO
> > const attributes instead than using the channel scale).
> >
> > Another question is where the standard IIO units are defined for each
> > channel type ?
>
> Should be in sysfs-bus-iio as above.  Usually in the relevant _raw
> description.
>
> Might be missing though for some unit types. If they are we should fix
> it!

Actually for concentration values the unit is reported and it is
expressed as percentage (10.000 ppm = 1%) so there shouldn't be
anything to add there.

Thanks
   j

>
> Jonathan
> >
> > Thanks
> >    j
> >
> > >
> > > Thanks,
> > >
> > > Matt
> > >
> > > > +               .ext_info = sunrise_concentration_ext_info,
> > > > +               .scan_index = 0,
> > > > +               .scan_type =  {
> > > > +                       .sign = 's',
> > > > +                       .realbits = 16,
> > > > +                       .storagebits = 16,
> > > > +                       .endianness = IIO_CPU,
> > > > +               },
> > > > +       },
> > > > +       {
> > > > +               .type = IIO_TEMP,
> > > > +               .info_mask_separate =  BIT(IIO_CHAN_INFO_RAW) |
> > > > +                                      BIT(IIO_CHAN_INFO_SCALE),
> > > > +               .scan_index = 1,
> > > > +               .scan_type =  {
> > > > +                       .sign = 's',
> > > > +                       .realbits = 16,
> > > > +                       .storagebits = 16,
> > > > +                       .endianness = IIO_CPU,
> > > > +               },
> > > > +       },
> > > > +};
> > > > +
> > > > +static int sunrise_read_raw(struct iio_dev *iio_dev,
> > > > +                           const struct iio_chan_spec *chan,
> > > > +                           int *val, int *val2, long mask)
> > > > +{
> > > > +       struct sunrise_dev *sunrise = iio_priv(iio_dev);
> > > > +       u16 value;
> > > > +       int ret;
> > > > +
> > > > +       switch (mask) {
> > > > +       case IIO_CHAN_INFO_RAW:
> > > > +               switch (chan->type) {
> > > > +               case IIO_CONCENTRATION:
> > > > +                       mutex_lock(&sunrise->lock);
> > > > +                       ret = sunrise_read_word(sunrise, SUNRISE_CO2_FILTERED_COMP_REG,
> > > > +                                               &value);
> > > > +                       *val = value;
> > > > +                       mutex_unlock(&sunrise->lock);
> > > > +
> > > > +                       if (ret)
> > > > +                               return ret;
> > > > +
> > > > +                       return IIO_VAL_INT;
> > > > +
> > > > +               case IIO_TEMP:
> > > > +                       mutex_lock(&sunrise->lock);
> > > > +                       ret = sunrise_read_word(sunrise, SUNRISE_CHIP_TEMPERATURE_REG,
> > > > +                                               &value);
> > > > +                       *val = value;
> > > > +                       mutex_unlock(&sunrise->lock);
> > > > +
> > > > +                       if (ret)
> > > > +                               return ret;
> > > > +
> > > > +                       return IIO_VAL_INT;
> > > > +
> > > > +               default:
> > > > +                       return -EINVAL;
> > > > +               }
> > > > +
> > > > +       case IIO_CHAN_INFO_SCALE:
> > > > +               /* x10 to comply with IIO scale (1/1000 degress celsius). */
> > > > +               *val = 10;
> > > > +               return IIO_VAL_INT;
> > > > +
> > > > +       default:
> > > > +               return -EINVAL;
> > > > +       }
> > > > +}
> > > > +
> > > > +static const struct iio_info sunrise_info = {
> > > > +       .read_raw = sunrise_read_raw,
> > > > +};
> > > > +
> > > > +static struct regmap_config sunrise_regmap_config = {
> > > > +       .reg_bits = 8,
> > > > +       .val_bits = 8,
> > > > +       /*
> > > > +        * Access to the i2c bus is locked by the driver to preserve the
> > > > +        * 'wakeup' session.
> > > > +        */
> > > > +       .disable_locking = true,
> > > > +};
> > > > +
> > > > +static int sunrise_probe(struct i2c_client *client)
> > > > +{
> > > > +       struct sunrise_dev *sunrise;
> > > > +       struct iio_dev *iio_dev;
> > > > +
> > > > +       iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*sunrise));
> > > > +       if (!iio_dev)
> > > > +               return -ENOMEM;
> > > > +
> > > > +       sunrise = iio_priv(iio_dev);
> > > > +       sunrise->client = client;
> > > > +       mutex_init(&sunrise->lock);
> > > > +       mutex_init(&sunrise->wakeup_lock);
> > > > +
> > > > +       sunrise->regmap = devm_regmap_init_i2c(client, &sunrise_regmap_config);
> > > > +       if (IS_ERR(sunrise->regmap)) {
> > > > +               dev_err(&client->dev, "Failed to initialize regmap\n");
> > > > +               return PTR_ERR(sunrise->regmap);
> > > > +       }
> > > > +
> > > > +       iio_dev->info = &sunrise_info;
> > > > +       iio_dev->name = DRIVER_NAME;
> > > > +       iio_dev->channels = sunrise_channels;
> > > > +       iio_dev->num_channels = ARRAY_SIZE(sunrise_channels);
> > > > +       iio_dev->modes = INDIO_DIRECT_MODE;
> > > > +
> > > > +       return devm_iio_device_register(&client->dev, iio_dev);
> > > > +}
> > > > +
> > > > +static const struct of_device_id sunrise_of_match[] = {
> > > > +       { .compatible = "senseair,sunrise-006-0-0007" },
> > > > +       {}
> > > > +};
> > > > +MODULE_DEVICE_TABLE(of, sunrise_of_match);
> > > > +
> > > > +static struct i2c_driver sunrise_driver = {
> > > > +       .driver = {
> > > > +               .name = DRIVER_NAME,
> > > > +               .of_match_table = sunrise_of_match,
> > > > +       },
> > > > +       .probe_new = sunrise_probe,
> > > > +};
> > > > +module_i2c_driver(sunrise_driver);
> > > > +
> > > > +MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>");
> > > > +MODULE_DESCRIPTION("Senseair Sunrise 006-0-0007 CO2 sensor IIO driver");
> > > > +MODULE_LICENSE("GPL v2");
> > > > --
> > > > 2.32.0
> > > >
>

[PATCH v4 3/3] iio: ABI: docs: Document Senseair Sunrise ABI

[Jacopo Mondi]

Add documentation for the sysfs attributes of the sunrise_co2 driver.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
---
 .../sysfs-bus-iio-chemical-sunrise-co2        | 38 +++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2 b/Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2
new file mode 100644
index 000000000000..bbdbf9dd4818
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2
@@ -0,0 +1,38 @@
+What:		/sys/bus/iio/devices/iio:deviceX/in_concentration_co2_calibration_factory
+Date:		August 2021
+KernelVersion:
+Contact:	Jacopo Mondi <jacopo@jmondi.org>
+Description:
+		Writing '1' triggers a 'Factory' calibration cycle.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_concentration_co2_calibration_background
+Date:		August 2021
+KernelVersion:
+Contact:	Jacopo Mondi <jacopo@jmondi.org>
+Description:
+		Writing '1' triggers a 'Background' calibration cycle.
+
+What:		/sys/bus/iio/devices/iio:deviceX/error_status_available
+Date:		August 2021
+KernelVersion:
+Contact:	Jacopo Mondi <jacopo@jmondi.org>
+Description:
+		Reading returns the list of possible chip error status.
+		Available options are:
+		- 'error_fatal': Analog front-end initialization error
+		- 'error_i2c': Read/write to non-existing register
+		- 'error_algorithm': Corrupted parameters
+		- 'error_calibration': Calibration has failed
+		- 'error_self_diagnostic': Internal interface failure
+		- 'error_out_of_range': Measured concentration out of scale
+		- 'error_memory': Error during memory operations
+		- 'error_no_measurement': Cleared at first measurement
+		- 'error_low_voltage': Sensor regulated voltage too low
+		- 'error_measurement_timeout': Unable to complete measurement
+
+What:		/sys/bus/iio/devices/iio:deviceX/error_status
+Date:		August 2021
+KernelVersion:
+Contact:	Jacopo Mondi <jacopo@jmondi.org>
+Description:
+		Reading returns the current chip error status.
-- 
2.32.0

Re: [PATCH v4 3/3] iio: ABI: docs: Document Senseair Sunrise ABI

[Jonathan Cameron]

On Fri,  3 Sep 2021 16:48:28 +0200
Jacopo Mondi <jacopo@jmondi.org> wrote:

> Add documentation for the sysfs attributes of the sunrise_co2 driver.
> 
> Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Nice but please fill in the version numbers with 5.16

Thanks,

Jonathan

> ---
>  .../sysfs-bus-iio-chemical-sunrise-co2        | 38 +++++++++++++++++++
>  1 file changed, 38 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2 b/Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2
> new file mode 100644
> index 000000000000..bbdbf9dd4818
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-chemical-sunrise-co2
> @@ -0,0 +1,38 @@
> +What:		/sys/bus/iio/devices/iio:deviceX/in_concentration_co2_calibration_factory
> +Date:		August 2021
> +KernelVersion:
> +Contact:	Jacopo Mondi <jacopo@jmondi.org>
> +Description:
> +		Writing '1' triggers a 'Factory' calibration cycle.
> +
> +What:		/sys/bus/iio/devices/iio:deviceX/in_concentration_co2_calibration_background
> +Date:		August 2021
> +KernelVersion:
> +Contact:	Jacopo Mondi <jacopo@jmondi.org>
> +Description:
> +		Writing '1' triggers a 'Background' calibration cycle.
> +
> +What:		/sys/bus/iio/devices/iio:deviceX/error_status_available
> +Date:		August 2021
> +KernelVersion:

Be an optimist and fill this in for v5!  I'll never remember to do it.
I'd be very surprised if we don't get this lined up for 5.16

> +Contact:	Jacopo Mondi <jacopo@jmondi.org>
> +Description:
> +		Reading returns the list of possible chip error status.
> +		Available options are:
> +		- 'error_fatal': Analog front-end initialization error
> +		- 'error_i2c': Read/write to non-existing register
> +		- 'error_algorithm': Corrupted parameters
> +		- 'error_calibration': Calibration has failed
> +		- 'error_self_diagnostic': Internal interface failure
> +		- 'error_out_of_range': Measured concentration out of scale
> +		- 'error_memory': Error during memory operations
> +		- 'error_no_measurement': Cleared at first measurement
> +		- 'error_low_voltage': Sensor regulated voltage too low
> +		- 'error_measurement_timeout': Unable to complete measurement
> +
> +What:		/sys/bus/iio/devices/iio:deviceX/error_status
> +Date:		August 2021
> +KernelVersion:
> +Contact:	Jacopo Mondi <jacopo@jmondi.org>
> +Description:
> +		Reading returns the current chip error status.