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Date: Sat, 10 Mar 2018 23:07:30 +0100
From: Andreas Brauchli <a.brauchli@...mentarea.net>
To: Jonathan Cameron <jic23@...nel.org>,
Hartmut Knaack <knaack.h@....de>,
Lars-Peter Clausen <lars@...afoo.de>,
Peter Meerwald-Stadler <pmeerw@...erw.net>,
Rob Herring <robh+dt@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Jonathan Corbet <corbet@....net>
Cc: linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org,
devicetree@...r.kernel.org, linux-doc@...r.kernel.org
Subject: [PATCH v2 2/2] iio: chemical: sgp30: Support Sensirion SGPxx sensors
Support Sensirion SGP30 and SGPC3 multi-pixel I2C gas sensors
Supported Features:
* Indoor Air Quality (IAQ) concentrations for
- tVOC (in_concentration_voc_input)
- CO2eq (in_concentration_co2_input) - SGP30 only
IAQ concentrations are periodically read out by a background thread
to allow the sensor to maintain its internal baseline.
* Baseline support for IAQ (in_iaq_baseline, set_iaq_baseline)
* Gas concentration signals
- Ethanol (in_concentration_ethanol_raw)
- H2 (in_concentration_h2_raw) - SGP30 only
* On-chip self test (in_selftest)
* Sensor interface version (in_feature_set_version)
* Sensor serial number (in_serial_id)
* Humidity compensation
With the help of an external humidity signal, the gas signals can be
humidity-compensated. The sensor performs the compensation on-chip.
* Power mode switching between low power mode (1/2Hz) and
ultra low power mode (1/30Hz) sampling - SGPC3 only
* Checksummed I2C communication
For all features, refer to the data sheet or the documentation in
Documentation/iio/chemical/sgp30.txt for more details.
The ABI is documented in
Documentation/ABI/testing/sysfs-bus-iio-chemical-sgp30
Signed-off-by: Andreas Brauchli <andreas.brauchli@...sirion.com>
---
.../ABI/testing/sysfs-bus-iio-chemical-sgp30 | 62 ++
.../bindings/iio/chemical/sensirion,sgp30.txt | 15 +
Documentation/iio/chemical/sgp30.txt | 97 ++
drivers/iio/chemical/Kconfig | 13 +
drivers/iio/chemical/Makefile | 1 +
drivers/iio/chemical/sgp30.c | 1120 ++++++++++++++++++++
6 files changed, 1308 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-chemical-sgp30
create mode 100644 Documentation/devicetree/bindings/iio/chemical/sensirion,sgp30.txt
create mode 100644 Documentation/iio/chemical/sgp30.txt
create mode 100644 drivers/iio/chemical/sgp30.c
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-chemical-sgp30 b/Documentation/ABI/testing/sysfs-bus-iio-chemical-sgp30
new file mode 100644
index 000000000000..3b97c0bd5878
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-chemical-sgp30
@@ -0,0 +1,62 @@
+what: /sys/bus/iio/devices/iio:devicex/in_featureset_version
+date: March 2018
+kernelversion: 4.17
+contact: andreas brauchli <andreas.brauchli@...sirion.com>
+description:
+ Retrieve the sensor interface version. The sensor-interface should
+ remain forward-compatible across minor versions.
+
+what: /sys/bus/iio/devices/iio:devicex/in_iaq_baseline
+date: March 2018
+kernelversion: 4.17
+contact: andreas brauchli <andreas.brauchli@...sirion.com>
+description:
+ Retrieve the on-chip iaq baseline state. the baseline is an internal
+ state that should not be modified.
+
+What: /sys/bus/iio/devices/iio:deviceX/set_iaq_baseline
+Date: March 2018
+KernelVersion: 4.17
+Contact: Andreas Brauchli <andreas.brauchli@...sirion.com>
+Description:
+ Restore the on-chip IAQ baseline state to a previous state. Useful for
+ fast-resuming after a restart. A baseline is valid for one week when the
+ sensor is not operated.
+
+What: /sys/bus/iio/devices/iio:deviceX/in_selftest
+Date: March 2018
+KernelVersion: 4.17
+Contact: Andreas Brauchli <andreas.brauchli@...sirion.com>
+Description:
+ Run the on-chip self test. Output values:
+ * OK
+ * FAILED
+
+What: /sys/bus/iio/devices/iio:deviceX/in_serial_id
+Date: March 2018
+KernelVersion: 4.17
+Contact: Andreas Brauchli <andreas.brauchli@...sirion.com>
+Description:
+ Retrieve the unique sensor serial number. May be useful to associate
+ with the IAQ baseline when the baseline is stored remotely or the sensor
+ is on a plug-and-play device.
+
+Date: March 2018
+KernelVersion: 4.17
+Contact: Andreas Brauchli <andreas.brauchli@...sirion.com>
+Description:
+ Set the absolute humidity in milligrams per cubic meter (mg/m^3) to
+ enable on-sensor humidity compensation. Affects all gas signals and IAQ
+ values. Accepted values:
+ * 0 (disables humidity compensation)
+ * 1..256000 (mg/m^3)
+
+What: /sys/bus/iio/devices/iio:deviceX/set_power_mode
+Date: March 2018
+KernelVersion: 4.17
+Contact: Andreas Brauchli <andreas.brauchli@...sirion.com>
+Description:
+ Change the power mode on an SGPC3 with ultra-low power mode support.
+ Accepted values:
+ * "low" (default/startup mode)
+ * "ultra-low" (default/startup mode)
diff --git a/Documentation/devicetree/bindings/iio/chemical/sensirion,sgp30.txt b/Documentation/devicetree/bindings/iio/chemical/sensirion,sgp30.txt
new file mode 100644
index 000000000000..bb909b0f1aba
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/chemical/sensirion,sgp30.txt
@@ -0,0 +1,15 @@
+* Sensirion SGPxx multi-pixel Gas Sensor
+
+Required properties:
+
+ - compatible: must be one of
+ "sensirion,sgp30"
+ "sensirion,sgpc3"
+ - reg: the I2C address of the sensor
+
+Example:
+
+sgpxx@58 {
+ compatible = "sensirion,sgp30";
+ reg = <0x58>;
+};
diff --git a/Documentation/iio/chemical/sgp30.txt b/Documentation/iio/chemical/sgp30.txt
new file mode 100644
index 000000000000..c236f7d0fa80
--- /dev/null
+++ b/Documentation/iio/chemical/sgp30.txt
@@ -0,0 +1,97 @@
+sgp30: Industrial IO driver for Sensirion I2C Multi-Pixel Gas Sensors
+
+1. Overview
+
+The sgp30 driver supports the Sensirion SGP30 and SGPC3 multi-pixel gas sensors.
+
+2. Modes of Operation
+
+Postprocessed Indoor Air Quality (IAQ) gas concentrations as well as raw gas
+signals are available. Both signals can be humidity-compensated by the sensor.
+
+2.1. IAQ Gas Concentrations
+
+* tVOC (in_concentration_voc_input) at ppb precision (1e-9)
+* CO2eq (in_concentration_co2_input) at ppm precision (1e-6) -- SGP30 only
+
+2.1.1. IAQ Initialization
+Before Indoor Air Quality (IAQ) values can be read, the IAQ mode must be
+initialized by sending the "iaq_init" command from the data sheet to the sensor.
+The sgp30 driver performs this initialization automatically on instantiation.
+
+After initializing IAQ, at least one IAQ signal must be read out every second
+(SGP30) / every two seconds (SGPC3) for the sensor to correctly maintain its
+internal baseline. The driver continuously performs this task in a background
+thread and caches the latest measurement for retrieval.
+
+For the first 15s of operation after "iaq_init", default values are returned by
+the sensor. Default values are not returned by the driver, instead an -EBUSY
+error is returned.
+
+2.1.2. Pausing and Resuming IAQ
+
+For best performance and faster subsequent startup times, the baseline should be
+saved once every hour, after 12h of operation. The baseline is restored by
+writing the last known baseline back to set_iaq_baseline.
+
+ Saving the baseline:
+ $ baseline=$(cat in_iaq_baseline)
+
+ Restoring the baseline:
+ $ echo -n $baseline > set_iaq_baseline
+
+2.2. Humidity Compensation
+
+The SGP features an on-chip humidity compensation that requires the (in-device)
+environment's absolute humidity.
+
+Set the absolute humidity by writing the absolute humidity concentration (in
+mg/m^3) to set_absolute_humidity. The absolute humidity is obtained by
+converting the relative humidity and temperature. The following units are used:
+AH in mg/m^3, RH in percent (0..100), T in degrees Celsius, and exp() being the
+base-e exponential function.
+
+ RH exp(17.62 * T)
+ ----- * 6.112 * --------------
+ 100.0 243.12 + T
+ AH = 216.7 * ------------------------------- * 1000
+ 273.15 + T
+
+Writing a value of 0 to set_absolute_humidity disables the humidity
+compensation. Devices not supporting humidity compensation (SGPC3 with feature
+set < 0.6) will report an error (-EINVAL) when setting the humidity.
+
+2.3. On-chip self test
+
+ $ cat in_selftest
+
+in_selftest returns OK or FAILED.
+
+On the SGP30, self test interferes with IAQ operations and requires a
+re-initialization thereof. If a valid baseline is available (after 12h of
+operation), the driver will take care of resuming the operation after the
+selftest, otherwise the "iaq_init" procedure will be restarted.
+
+2.4 SGPC3 Low Power Gas Sensor Features
+
+2.4.1 Accelerated Startup
+
+The SGPC3 can be pre-heated differently by writing a duration to the
+set_iaq_preheat_seconds attribute. Pre-heating causes the sensor to draw more
+power but results in more accurate readings, thus also marketed as accelerated
+startup mode. Sensors prior to feature set 0.6 allow pre-heating durations of 0,
+16, 64 and 184s (other values rounded to the next higher setting). Feature set
+0.6 allows pre-heating for all integer durations up to 300s (a software limit).
+
+Pre-heating occurs on IAQ initialization, thus after changing the power mode or
+setting an IAQ baseline. When the sensor has been operated for a duration of
+12h or more, it is not necessary to pre-heat after short down periods (e.g.
+reboots of < 5min.)
+
+2.4.2 Ultra Low Power Mode (SGPC3 Feature Set 0.6+)
+
+The SGPC3 with feature set 0.6+ features an ultra-low-power mode in which the
+sensor is only polled every 30s instead of every 2s. The polling interval in the
+background thread is adjusted by the driver when changing the power mode with
+set_power_mode. Supported options: {"low", "ultra-low"}. Changing the power mode
+on sensors without power-mode switching results in an -EINVAL error.
diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
index 5cb5be7612b4..6f0e2d1240bd 100644
--- a/drivers/iio/chemical/Kconfig
+++ b/drivers/iio/chemical/Kconfig
@@ -38,6 +38,19 @@ config IAQCORE
iAQ-Core Continuous/Pulsed VOC (Volatile Organic Compounds)
sensors
+config SENSIRION_SGP30
+ tristate "Sensirion SGPxx gas sensors"
+ depends on I2C
+ select CRC8
+ help
+ Say Y here to build I2C interface support for the following
+ Sensirion SGP gas sensors:
+ * SGP30 gas sensor
+ * SGPC3 low power gas sensor
+
+ To compile this driver as module, choose M here: the
+ module will be called sgp30.
+
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 a629b29d1e0b..9aeb3fce1408 100644
--- a/drivers/iio/chemical/Makefile
+++ b/drivers/iio/chemical/Makefile
@@ -6,4 +6,5 @@
obj-$(CONFIG_ATLAS_PH_SENSOR) += atlas-ph-sensor.o
obj-$(CONFIG_CCS811) += ccs811.o
obj-$(CONFIG_IAQCORE) += ams-iaq-core.o
+obj-$(CONFIG_SENSIRION_SGP30) += sgp30.o
obj-$(CONFIG_VZ89X) += vz89x.o
diff --git a/drivers/iio/chemical/sgp30.c b/drivers/iio/chemical/sgp30.c
new file mode 100644
index 000000000000..f336a89ad906
--- /dev/null
+++ b/drivers/iio/chemical/sgp30.c
@@ -0,0 +1,1120 @@
+/*
+ * sgp30.c - Support for Sensirion SGP Gas Sensors
+ *
+ * Copyright (C) 2017 Andreas Brauchli <andreas.brauchli@...sirion.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * Datasheets:
+ * https://www.sensirion.com/file/datasheet_sgp30
+ * https://www.sensirion.com/file/datasheet_sgpc3
+ */
+
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/of_device.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/sysfs.h>
+#include <linux/string.h>
+#include <linux/version.h>
+
+#define SGP_WORD_LEN 2
+#define SGP_CRC8_POLYNOMIAL 0x31
+#define SGP_CRC8_INIT 0xff
+#define SGP_CRC8_LEN 1
+#define SGP_CMD(cmd_word) cpu_to_be16(cmd_word)
+#define SGP_CMD_DURATION_US 12000
+#define SGP_MEASUREMENT_DURATION_US 50000
+#define SGP_SELFTEST_DURATION_US 220000
+#define SGP_CMD_HANDLING_DURATION_US 10000
+#define SGP_CMD_LEN SGP_WORD_LEN
+#define SGP_CMD_MAX_BUF_SIZE (SGP_CMD_LEN + 2 * SGP_WORD_LEN)
+#define SGP_MEASUREMENT_LEN 2
+#define SGP30_MEASURE_INTERVAL_HZ 1
+#define SGPC3_MEASURE_INTERVAL_HZ 2
+#define SGPC3_MEASURE_ULP_INTERVAL_HZ 30
+#define SGPC3_POWER_MODE_ULTRA_LOW_POWER 0
+#define SGPC3_POWER_MODE_LOW_POWER 1
+#define SGPC3_DEFAULT_IAQ_INIT_DURATION_HZ 64
+#define SGP_SELFTEST_OK 0xd400
+#define SGP_VERS_PRODUCT(data) ((((data)->feature_set) & 0xf000) >> 12)
+#define SGP_VERS_RESERVED(data) ((((data)->feature_set) & 0x0e00) >> 9)
+#define SGP_VERS_ENG_BIT(data) ((((data)->feature_set) & 0x0100) >> 8)
+#define SGP_VERS_MAJOR(data) ((((data)->feature_set) & 0x00e0) >> 5)
+#define SGP_VERS_MINOR(data) (((data)->feature_set) & 0x001f)
+
+DECLARE_CRC8_TABLE(sgp_crc8_table);
+
+enum sgp_product_id {
+ SGP30 = 0,
+ SGPC3,
+};
+
+enum sgp30_channel_idx {
+ SGP30_IAQ_TVOC_IDX = 0,
+ SGP30_IAQ_CO2EQ_IDX,
+ SGP30_SIG_ETOH_IDX,
+ SGP30_SIG_H2_IDX,
+};
+
+enum sgpc3_channel_idx {
+ SGPC3_IAQ_TVOC_IDX = 10,
+ SGPC3_SIG_ETOH_IDX,
+};
+
+enum sgp_cmd {
+ SGP_CMD_IAQ_INIT = SGP_CMD(0x2003),
+ SGP_CMD_IAQ_MEASURE = SGP_CMD(0x2008),
+ SGP_CMD_GET_BASELINE = SGP_CMD(0x2015),
+ SGP_CMD_SET_BASELINE = SGP_CMD(0x201e),
+ SGP_CMD_GET_FEATURE_SET = SGP_CMD(0x202f),
+ SGP_CMD_GET_SERIAL_ID = SGP_CMD(0x3682),
+ SGP_CMD_SELFTEST = SGP_CMD(0x2032),
+ SGP_CMD_SET_ABSOLUTE_HUMIDITY = SGP_CMD(0x2061),
+
+ SGP30_CMD_MEASURE_SIGNAL = SGP_CMD(0x2050),
+
+ SGPC3_CMD_IAQ_INIT_0 = SGP_CMD(0x2089),
+ SGPC3_CMD_IAQ_INIT_16 = SGP_CMD(0x2024),
+ SGPC3_CMD_IAQ_INIT_64 = SGP_CMD(0x2003),
+ SGPC3_CMD_IAQ_INIT_184 = SGP_CMD(0x206a),
+ SGPC3_CMD_IAQ_INIT_CONTINUOUS = SGP_CMD(0x20ae),
+ SGPC3_CMD_MEASURE_RAW = SGP_CMD(0x2046),
+ SGPC3_CMD_SET_POWER_MODE = SGP_CMD(0x209f),
+};
+
+struct sgp_version {
+ u8 major;
+ u8 minor;
+};
+
+struct sgp_crc_word {
+ __be16 value;
+ u8 crc8;
+} __attribute__((__packed__));
+
+union sgp_reading {
+ u8 start;
+ struct sgp_crc_word raw_words[4];
+};
+
+enum _iaq_buffer_state {
+ IAQ_BUFFER_EMPTY = 0,
+ IAQ_BUFFER_DEFAULT_VALS,
+ IAQ_BUFFER_VALID,
+};
+
+struct sgp_data {
+ struct i2c_client *client;
+ struct task_struct *iaq_thread;
+ struct mutex data_lock;
+ unsigned long iaq_init_start_jiffies;
+ unsigned long iaq_init_duration_jiffies;
+ unsigned long iaq_defval_skip_jiffies;
+ u64 serial_id;
+ void (*iaq_init_fn)(struct sgp_data *data);
+ u32 iaq_init_user_duration;
+ u16 product_id;
+ u16 feature_set;
+ unsigned long measure_interval_jiffies;
+ enum sgp_cmd iaq_init_cmd;
+ enum sgp_cmd measure_iaq_cmd;
+ enum sgp_cmd measure_gas_signals_cmd;
+ u8 baseline_len;
+ u16 user_baseline[2];
+ u16 power_mode;
+ union sgp_reading buffer;
+ union sgp_reading iaq_buffer;
+ enum _iaq_buffer_state iaq_buffer_state;
+ bool supports_humidity_compensation;
+ bool supports_power_mode;
+};
+
+struct sgp_device {
+ const struct iio_chan_spec *channels;
+ int num_channels;
+};
+
+static const struct sgp_version supported_versions_sgp30[] = {
+ {
+ .major = 1,
+ .minor = 0,
+ },
+};
+
+static const struct sgp_version supported_versions_sgpc3[] = {
+ {
+ .major = 0,
+ .minor = 4,
+ },
+};
+
+static const struct iio_chan_spec sgp30_channels[] = {
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_VOC,
+ .datasheet_name = "TVOC signal",
+ .modified = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .address = SGP30_IAQ_TVOC_IDX,
+ },
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_CO2,
+ .datasheet_name = "CO2eq signal",
+ .modified = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .address = SGP30_IAQ_CO2EQ_IDX,
+ },
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_ETHANOL,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .address = SGP30_SIG_ETOH_IDX,
+ .datasheet_name = "Ethanol signal",
+ .modified = 1,
+ .scan_type = {
+ .endianness = IIO_BE,
+ },
+ },
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_H2,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .address = SGP30_SIG_H2_IDX,
+ .datasheet_name = "H2 signal",
+ .modified = 1,
+ .scan_type = {
+ .endianness = IIO_BE,
+ },
+ },
+};
+
+static const struct iio_chan_spec sgpc3_channels[] = {
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_VOC,
+ .datasheet_name = "TVOC signal",
+ .modified = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .address = SGPC3_IAQ_TVOC_IDX,
+ },
+ {
+ .type = IIO_CONCENTRATION,
+ .channel2 = IIO_MOD_ETHANOL,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .address = SGPC3_SIG_ETOH_IDX,
+ .datasheet_name = "Ethanol signal",
+ .modified = 1,
+ .scan_type = {
+ .endianness = IIO_BE,
+ },
+ },
+};
+
+static const struct sgp_device sgp_devices[] = {
+ [SGP30] = {
+ .channels = sgp30_channels,
+ .num_channels = ARRAY_SIZE(sgp30_channels),
+ },
+ [SGPC3] = {
+ .channels = sgpc3_channels,
+ .num_channels = ARRAY_SIZE(sgpc3_channels),
+ },
+};
+
+/**
+ * sgp_verify_buffer() - verify the checksums of the data buffer words
+ *
+ * @data: SGP data
+ * @buf: Raw data buffer
+ * @word_count: Num data words stored in the buffer, excluding CRC bytes
+ *
+ * Return: 0 on success, negative error otherwise.
+ */
+static int sgp_verify_buffer(const struct sgp_data *data,
+ union sgp_reading *buf, size_t word_count)
+{
+ size_t size = word_count * (SGP_WORD_LEN + SGP_CRC8_LEN);
+ int i;
+ u8 crc;
+ u8 *data_buf = &buf->start;
+
+ for (i = 0; i < size; i += SGP_WORD_LEN + SGP_CRC8_LEN) {
+ crc = crc8(sgp_crc8_table, &data_buf[i], SGP_WORD_LEN,
+ SGP_CRC8_INIT);
+ if (crc != data_buf[i + SGP_WORD_LEN]) {
+ dev_err(&data->client->dev, "CRC error\n");
+ return -EIO;
+ }
+ }
+ return 0;
+}
+
+/**
+ * sgp_read_cmd() - reads data from sensor after issuing a command
+ * The caller must hold data->data_lock for the duration of the call.
+ * @data: SGP data
+ * @cmd: SGP Command to issue
+ * @buf: Raw data buffer to use
+ * @word_count: Num words to read, excluding CRC bytes
+ *
+ * Return: 0 on success, negative error otherwise.
+ */
+static int sgp_read_cmd(struct sgp_data *data, enum sgp_cmd cmd,
+ union sgp_reading *buf, size_t word_count,
+ unsigned long duration_us)
+{
+ int ret;
+ struct i2c_client *client = data->client;
+ size_t size = word_count * (SGP_WORD_LEN + SGP_CRC8_LEN);
+ u8 *data_buf;
+
+ ret = i2c_master_send(client, (const char *)&cmd, SGP_CMD_LEN);
+ if (ret != SGP_CMD_LEN)
+ return -EIO;
+ usleep_range(duration_us, duration_us + 1000);
+
+ if (word_count == 0)
+ return 0;
+
+ data_buf = &buf->start;
+ ret = i2c_master_recv(client, data_buf, size);
+ if (ret < 0)
+ return ret;
+ if (ret != size)
+ return -EIO;
+
+ return sgp_verify_buffer(data, buf, word_count);
+}
+
+/**
+ * sgp_i2c_write_cmd() - write data to SGP sensor with a command
+ * @data: SGP data
+ * @cmd: SGP Command to issue
+ * @buf: Data to write
+ * @buf_size: Data size of the buffer
+ *
+ * Return: 0 on success, negative error otherwise.
+ */
+static int sgp_write_cmd(struct sgp_data *data, enum sgp_cmd cmd, u16 *buf,
+ size_t buf_size, unsigned long duration_us)
+{
+ int ret, ix;
+ u16 buf_idx;
+ u8 buffer[SGP_CMD_MAX_BUF_SIZE];
+
+ /* assemble buffer */
+ *((__be16 *)&buffer[0]) = cmd;
+ buf_idx = SGP_CMD_LEN;
+ for (ix = 0; ix < buf_size; ix++) {
+ *((__be16 *)&buffer[buf_idx]) = cpu_to_be16(buf[ix]);
+ buf_idx += SGP_WORD_LEN;
+ buffer[buf_idx] = crc8(sgp_crc8_table,
+ &buffer[buf_idx - SGP_WORD_LEN],
+ SGP_WORD_LEN, SGP_CRC8_INIT);
+ buf_idx += SGP_CRC8_LEN;
+ }
+ ret = i2c_master_send(data->client, buffer, buf_idx);
+ if (ret != buf_idx)
+ return -EIO;
+ ret = 0;
+ usleep_range(duration_us, duration_us + 1000);
+
+ return ret;
+}
+
+/**
+ * sgp_measure_iaq() - measure and retrieve IAQ values from sensor
+ * The caller must hold data->data_lock for the duration of the call.
+ * @data: SGP data
+ *
+ * Return: 0 on success, -EBUSY on default values, negative error
+ * otherwise.
+ */
+
+static int sgp_measure_iaq(struct sgp_data *data)
+{
+ int ret;
+ /* data contains default values */
+ bool default_vals = !time_after(jiffies, data->iaq_init_start_jiffies +
+ data->iaq_defval_skip_jiffies);
+
+ ret = sgp_read_cmd(data, data->measure_iaq_cmd, &data->iaq_buffer,
+ SGP_MEASUREMENT_LEN, SGP_MEASUREMENT_DURATION_US);
+ if (ret < 0)
+ return ret;
+
+ data->iaq_buffer_state = IAQ_BUFFER_DEFAULT_VALS;
+
+ if (default_vals)
+ return -EBUSY;
+
+ data->iaq_buffer_state = IAQ_BUFFER_VALID;
+ return 0;
+}
+
+static void sgp_iaq_thread_sleep_until(const struct sgp_data *data,
+ unsigned long sleep_jiffies)
+{
+ const long IAQ_POLL = 50000;
+
+ while (!time_after(jiffies, sleep_jiffies)) {
+ usleep_range(IAQ_POLL, IAQ_POLL + 10000);
+ if (kthread_should_stop() || data->iaq_init_start_jiffies == 0)
+ return;
+ }
+}
+
+static int sgp_iaq_threadfn(void *p)
+{
+ struct sgp_data *data = (struct sgp_data *)p;
+ unsigned long next_update_jiffies;
+ int ret;
+
+ while (!kthread_should_stop()) {
+ mutex_lock(&data->data_lock);
+ if (data->iaq_init_start_jiffies == 0) {
+ if (data->iaq_init_fn)
+ data->iaq_init_fn(data);
+ ret = sgp_read_cmd(data, data->iaq_init_cmd, NULL, 0,
+ SGP_CMD_DURATION_US);
+ if (ret < 0)
+ goto unlock_sleep_continue;
+ data->iaq_init_start_jiffies = jiffies;
+ if (data->user_baseline[0]) {
+ ret = sgp_write_cmd(data, SGP_CMD_SET_BASELINE,
+ data->user_baseline,
+ data->baseline_len,
+ SGP_CMD_DURATION_US);
+ if (ret < 0) {
+ dev_err(&data->client->dev,
+ "IAQ set baseline failed [%d]\n",
+ ret);
+ goto unlock_sleep_continue;
+ }
+ }
+ if (data->iaq_init_duration_jiffies) {
+ mutex_unlock(&data->data_lock);
+ sgp_iaq_thread_sleep_until(data,
+ data->iaq_init_start_jiffies +
+ data->iaq_init_duration_jiffies);
+ continue;
+ }
+ }
+
+ ret = sgp_measure_iaq(data);
+ if (ret && ret != -EBUSY) {
+ dev_warn(&data->client->dev, "IAQ measurement error [%d]\n",
+ ret);
+ }
+unlock_sleep_continue:
+ next_update_jiffies = jiffies + data->measure_interval_jiffies;
+ mutex_unlock(&data->data_lock);
+ sgp_iaq_thread_sleep_until(data, next_update_jiffies);
+ }
+ return 0;
+}
+
+static ssize_t sgp_absolute_humidity_store(struct device *dev,
+ __attribute__((unused))
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct sgp_data *data = iio_priv(dev_to_iio_dev(dev));
+ u32 ah;
+ u16 ah_scaled;
+ int ret;
+
+ if (!data->supports_humidity_compensation)
+ return -EINVAL;
+
+ ret = kstrtou32(buf, 10, &ah);
+ if (ret != 1 || ah < 0 || ah > 256000)
+ return -EINVAL;
+
+ /* ah_scaled = (u16)((ah / 1000.0) * 256.0) */
+ ah_scaled = (u16)(((u64)ah * 256 * 16777) >> 24);
+
+ /* don't disable AH compensation due to rounding */
+ if (ah > 0 && ah_scaled == 0)
+ ah_scaled = 1;
+
+ mutex_lock(&data->data_lock);
+ ret = sgp_write_cmd(data, SGP_CMD_SET_ABSOLUTE_HUMIDITY,
+ &ah_scaled, 1, SGP_CMD_DURATION_US);
+ mutex_unlock(&data->data_lock);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static int sgp_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct sgp_data *data = iio_priv(indio_dev);
+ struct sgp_crc_word *words;
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_PROCESSED:
+ mutex_lock(&data->data_lock);
+ if (data->iaq_buffer_state != IAQ_BUFFER_VALID) {
+ mutex_unlock(&data->data_lock);
+ return -EBUSY;
+ }
+ words = data->iaq_buffer.raw_words;
+ switch (chan->address) {
+ case SGP30_IAQ_TVOC_IDX:
+ case SGPC3_IAQ_TVOC_IDX:
+ *val = 0;
+ *val2 = be16_to_cpu(words[1].value);
+ ret = IIO_VAL_INT_PLUS_NANO;
+ break;
+ case SGP30_IAQ_CO2EQ_IDX:
+ *val = 0;
+ *val2 = be16_to_cpu(words[0].value);
+ ret = IIO_VAL_INT_PLUS_MICRO;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ mutex_unlock(&data->data_lock);
+ break;
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&data->data_lock);
+ if (chan->address == SGPC3_SIG_ETOH_IDX) {
+ if (data->iaq_buffer_state == IAQ_BUFFER_EMPTY)
+ ret = -EBUSY;
+ else
+ ret = 0;
+ words = data->iaq_buffer.raw_words;
+ } else {
+ ret = sgp_read_cmd(data, data->measure_gas_signals_cmd,
+ &data->buffer, SGP_MEASUREMENT_LEN,
+ SGP_MEASUREMENT_DURATION_US);
+ words = data->buffer.raw_words;
+ }
+ if (ret) {
+ mutex_unlock(&data->data_lock);
+ return ret;
+ }
+
+ switch (chan->address) {
+ case SGP30_SIG_ETOH_IDX:
+ *val = be16_to_cpu(words[1].value);
+ ret = IIO_VAL_INT;
+ break;
+ case SGPC3_SIG_ETOH_IDX:
+ case SGP30_SIG_H2_IDX:
+ *val = be16_to_cpu(words[0].value);
+ ret = IIO_VAL_INT;
+ break;
+ }
+ mutex_unlock(&data->data_lock);
+ break;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->address) {
+ case SGP30_SIG_ETOH_IDX:
+ case SGPC3_SIG_ETOH_IDX:
+ case SGP30_SIG_H2_IDX:
+ *val = 0;
+ *val2 = 1953125;
+ return IIO_VAL_INT_PLUS_NANO;
+ default:
+ return -EINVAL;
+ }
+ default:
+ return -EINVAL;
+ }
+ return ret;
+}
+
+static void sgp_restart_iaq_thread(struct sgp_data *data)
+{
+ mutex_lock(&data->data_lock);
+ data->iaq_buffer_state = IAQ_BUFFER_EMPTY;
+ data->iaq_init_start_jiffies = 0;
+ mutex_unlock(&data->data_lock);
+}
+
+static void sgpc3_iaq_init(struct sgp_data *data)
+{
+ int skip_cycles;
+
+ data->iaq_init_duration_jiffies = data->iaq_init_user_duration * HZ;
+ if (data->supports_power_mode) {
+ data->iaq_init_cmd = SGPC3_CMD_IAQ_INIT_CONTINUOUS;
+
+ if (data->power_mode == SGPC3_POWER_MODE_ULTRA_LOW_POWER) {
+ data->measure_interval_jiffies =
+ SGPC3_MEASURE_ULP_INTERVAL_HZ * HZ;
+ } else {
+ data->measure_interval_jiffies =
+ SGPC3_MEASURE_INTERVAL_HZ * HZ;
+ }
+
+ if (data->user_baseline[0])
+ skip_cycles = 1;
+ else if (data->power_mode == SGPC3_POWER_MODE_ULTRA_LOW_POWER)
+ skip_cycles = 2;
+ else
+ skip_cycles = 11;
+ } else {
+ switch (data->iaq_init_user_duration) {
+ case 0:
+ data->iaq_init_cmd = SGPC3_CMD_IAQ_INIT_0;
+ skip_cycles = 1;
+ break;
+ case 16:
+ data->iaq_init_cmd = SGPC3_CMD_IAQ_INIT_16;
+ skip_cycles = 9;
+ break;
+ case 64:
+ data->iaq_init_cmd = SGPC3_CMD_IAQ_INIT_64;
+ skip_cycles = 33;
+ break;
+ case 184:
+ data->iaq_init_cmd = SGPC3_CMD_IAQ_INIT_184;
+ skip_cycles = 93;
+ break;
+ default:
+ data->iaq_init_cmd = SGPC3_CMD_IAQ_INIT_64;
+ skip_cycles = 33;
+ break;
+ }
+ if (!data->user_baseline[0])
+ skip_cycles += 10;
+ }
+ data->iaq_defval_skip_jiffies = data->iaq_init_duration_jiffies +
+ (skip_cycles *
+ data->measure_interval_jiffies);
+}
+
+static ssize_t sgp_iaq_preheat_store(struct device *dev,
+ __attribute__((unused))
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct sgp_data *data = iio_priv(dev_to_iio_dev(dev));
+ u32 init_duration;
+ int ret;
+
+ if (SGP_VERS_PRODUCT(data) != SGPC3)
+ return -EINVAL;
+
+ mutex_lock(&data->data_lock);
+ ret = kstrtou32(buf, 10, &init_duration);
+ if (ret) {
+ ret = -EINVAL;
+ goto unlock_fail;
+ }
+
+ if (data->supports_power_mode) {
+ if (init_duration > 300) {
+ ret = -EINVAL;
+ goto unlock_fail;
+ }
+ } else {
+ if (init_duration == 0) {
+ } else if (init_duration <= 16) {
+ init_duration = 16;
+ } else if (init_duration <= 64) {
+ init_duration = 64;
+ } else if (init_duration <= 184) {
+ init_duration = 184;
+ } else {
+ ret = -EINVAL;
+ goto unlock_fail;
+ }
+ }
+
+ data->iaq_init_user_duration = init_duration;
+ mutex_unlock(&data->data_lock);
+
+ return count;
+
+unlock_fail:
+ mutex_unlock(&data->data_lock);
+ return ret;
+}
+
+static ssize_t sgp_power_mode_store(struct device *dev,
+ __attribute__((unused))
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct sgp_data *data = iio_priv(dev_to_iio_dev(dev));
+ u16 power_mode;
+ int ret;
+ const char ULTRA_LOW[] = "ultra-low";
+ const char LOW[] = "low";
+
+ if (!data->supports_power_mode)
+ return -EINVAL;
+
+ if (strncmp(buf, ULTRA_LOW, sizeof(ULTRA_LOW) - 1) == 0)
+ power_mode = SGPC3_POWER_MODE_ULTRA_LOW_POWER;
+ else if (strncmp(buf, LOW, sizeof(LOW) - 1) == 0)
+ power_mode = SGPC3_POWER_MODE_LOW_POWER;
+ else
+ return -EINVAL;
+
+ mutex_lock(&data->data_lock);
+ if (power_mode == data->power_mode) {
+ mutex_unlock(&data->data_lock);
+ return count;
+ }
+
+ /* Switching power mode invalidates any set baselines */
+ if (power_mode != data->power_mode) {
+ data->user_baseline[0] = 0;
+ data->user_baseline[1] = 0;
+ }
+
+ ret = sgp_write_cmd(data, SGPC3_CMD_SET_POWER_MODE,
+ &power_mode, 1, SGP_CMD_DURATION_US);
+ if (ret) {
+ mutex_unlock(&data->data_lock);
+ return ret;
+ }
+ data->power_mode = power_mode;
+ mutex_unlock(&data->data_lock);
+
+ sgp_restart_iaq_thread(data);
+ return count;
+}
+
+static int sgp_get_baseline(struct sgp_data *data, u16 *baseline_words)
+{
+ u16 baseline_word;
+ int ret, ix, jx;
+
+ mutex_lock(&data->data_lock);
+ ret = sgp_read_cmd(data, SGP_CMD_GET_BASELINE, &data->buffer,
+ data->baseline_len, SGP_CMD_DURATION_US);
+ if (ret < 0)
+ goto unlock_fail;
+
+ for (ix = 0, jx = data->baseline_len - 1; ix < data->baseline_len;
+ ix++, jx--) {
+ baseline_word = be16_to_cpu(data->buffer.raw_words[jx].value);
+ baseline_words[ix] = baseline_word;
+ }
+
+ if (!baseline_words[0])
+ ret = -EBUSY;
+
+unlock_fail:
+ mutex_unlock(&data->data_lock);
+ return ret;
+}
+
+static ssize_t sgp_iaq_baseline_show(struct device *dev,
+ __attribute__((unused))
+ struct device_attribute *attr,
+ char *buf)
+{
+ int ret;
+ u16 baseline_words[2];
+ struct sgp_data *data = iio_priv(dev_to_iio_dev(dev));
+
+ ret = sgp_get_baseline(data, baseline_words);
+ if (ret < 0)
+ return ret;
+
+ if (data->baseline_len == 1)
+ return sprintf(buf, "%04hx\n", baseline_words[0]);
+
+ return sprintf(buf, "%04hx%04hx\n", baseline_words[0],
+ baseline_words[1]);
+}
+
+/**
+ * Retrieve the sensor's baseline and report whether it's valid for persistence
+ * @baseline: sensor's current baseline
+ *
+ * Return: 1 if the baseline was set manually or the sensor has been
+ * operating for at least 12h, -EBUSY if the baseline is not yet
+ * valid, another negative error otherwise.
+ */
+static int sgp_is_baseline_valid(struct sgp_data *data, u16 *baseline_words)
+{
+ int ret;
+
+ ret = sgp_get_baseline(data, baseline_words);
+ if (ret < 0)
+ return ret;
+
+ mutex_lock(&data->data_lock);
+ ret = (data->user_baseline[0] ||
+ time_after(jiffies,
+ data->iaq_init_start_jiffies + 60 * 60 * 12 * HZ));
+ mutex_unlock(&data->data_lock);
+
+ return ret;
+}
+
+static void sgp_set_baseline(struct sgp_data *data, u16 *baseline_words)
+{
+ mutex_lock(&data->data_lock);
+ data->user_baseline[0] = baseline_words[0];
+ if (data->baseline_len == 2)
+ data->user_baseline[1] = baseline_words[1];
+ mutex_unlock(&data->data_lock);
+ sgp_restart_iaq_thread(data);
+}
+
+static ssize_t sgp_iaq_baseline_store(struct device *dev,
+ __attribute__((unused))
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct sgp_data *data = iio_priv(dev_to_iio_dev(dev));
+ int newline = (count > 0 && buf[count - 1] == '\n');
+ u16 words[2];
+ int ret = 0;
+
+ if (count - newline == (data->baseline_len * 4)) {
+ if (data->baseline_len == 1)
+ ret = sscanf(buf, "%04hx", &words[0]);
+ else
+ ret = sscanf(buf, "%04hx%04hx", &words[0], &words[1]);
+ }
+
+ if (ret != data->baseline_len) {
+ dev_err(&data->client->dev, "invalid baseline format\n");
+ return -EINVAL;
+ }
+
+ sgp_set_baseline(data, words);
+ return count;
+}
+
+static ssize_t sgp_selftest_show(struct device *dev,
+ __attribute__((unused))
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct sgp_data *data = iio_priv(dev_to_iio_dev(dev));
+ u16 baseline_words[2];
+ u16 measure_test;
+ int baseline_valid = 0;
+ int ret;
+
+ if (data->product_id == SGP30) {
+ /* On the SGP30, the self-test interferes with iaq_init */
+ baseline_valid = sgp_is_baseline_valid(data, baseline_words);
+ }
+
+ mutex_lock(&data->data_lock);
+ ret = sgp_read_cmd(data, SGP_CMD_SELFTEST, &data->buffer,
+ 1, SGP_SELFTEST_DURATION_US);
+ if (ret < 0) {
+ mutex_unlock(&data->data_lock);
+ return ret;
+ }
+
+ measure_test = be16_to_cpu(data->buffer.raw_words[0].value);
+ mutex_unlock(&data->data_lock);
+
+ if (data->product_id == SGP30) {
+ if (baseline_valid > 0)
+ sgp_set_baseline(data, baseline_words);
+ else
+ sgp_restart_iaq_thread(data);
+ }
+
+ return sprintf(buf, "%s\n",
+ measure_test ^ SGP_SELFTEST_OK ? "FAILED" : "OK");
+}
+
+static ssize_t sgp_serial_id_show(struct device *dev,
+ __attribute__((unused))
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct sgp_data *data = iio_priv(dev_to_iio_dev(dev));
+
+ return sprintf(buf, "%llu\n", data->serial_id);
+}
+
+static ssize_t sgp_feature_set_version_show(struct device *dev,
+ __attribute__((unused))
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct sgp_data *data = iio_priv(dev_to_iio_dev(dev));
+
+ return sprintf(buf, "%hu.%hu\n", (data->feature_set & 0x00e0) >> 5,
+ data->feature_set & 0x001f);
+}
+
+static int sgp_get_serial_id(struct sgp_data *data)
+{
+ int ret;
+ struct sgp_crc_word *words;
+
+ mutex_lock(&data->data_lock);
+ ret = sgp_read_cmd(data, SGP_CMD_GET_SERIAL_ID, &data->buffer, 3,
+ SGP_CMD_DURATION_US);
+ if (ret < 0)
+ goto unlock_fail;
+
+ words = data->buffer.raw_words;
+ data->serial_id = (u64)(be16_to_cpu(words[2].value) & 0xffff) |
+ (u64)(be16_to_cpu(words[1].value) & 0xffff) << 16 |
+ (u64)(be16_to_cpu(words[0].value) & 0xffff) << 32;
+
+unlock_fail:
+ mutex_unlock(&data->data_lock);
+ return ret;
+}
+
+static int sgp_check_compat(struct sgp_data *data,
+ unsigned int product_id)
+{
+ struct sgp_version *supported_versions;
+ u16 ix, num_fs;
+ u16 product = SGP_VERS_PRODUCT(data);
+ u16 reserved = SGP_VERS_RESERVED(data);
+ u16 major = SGP_VERS_MAJOR(data);
+ u16 minor = SGP_VERS_MINOR(data);
+
+ /* driver does not match product */
+ if (product != product_id) {
+ dev_err(&data->client->dev,
+ "sensor reports a different product: 0x%04hx\n",
+ product);
+ return -ENODEV;
+ }
+ if (reserved) {
+ dev_warn(&data->client->dev, "reserved bits set: 0x%04hx\n",
+ reserved);
+ }
+ /* engineering samples are not supported: no interface guarantees */
+ if (SGP_VERS_ENG_BIT(data))
+ return -ENODEV;
+
+ switch (product) {
+ case SGP30:
+ supported_versions =
+ (struct sgp_version *)supported_versions_sgp30;
+ num_fs = ARRAY_SIZE(supported_versions_sgp30);
+ break;
+ case SGPC3:
+ supported_versions =
+ (struct sgp_version *)supported_versions_sgpc3;
+ num_fs = ARRAY_SIZE(supported_versions_sgpc3);
+ break;
+ default:
+ return -ENODEV;
+ }
+
+ for (ix = 0; ix < num_fs; ix++) {
+ if (major == supported_versions[ix].major &&
+ minor >= supported_versions[ix].minor)
+ return 0;
+ }
+ dev_err(&data->client->dev, "unsupported sgp version: %d.%d\n",
+ major, minor);
+ return -ENODEV;
+}
+
+static void sgp_init(struct sgp_data *data)
+{
+ data->iaq_init_cmd = SGP_CMD_IAQ_INIT;
+ data->iaq_init_start_jiffies = 0;
+ data->iaq_init_duration_jiffies = 0;
+ data->iaq_init_user_duration = 0;
+ data->iaq_init_fn = NULL;
+ data->iaq_buffer_state = IAQ_BUFFER_EMPTY;
+ data->user_baseline[0] = 0;
+ data->user_baseline[1] = 0;
+ switch (SGP_VERS_PRODUCT(data)) {
+ case SGP30:
+ data->measure_interval_jiffies = SGP30_MEASURE_INTERVAL_HZ * HZ;
+ data->measure_iaq_cmd = SGP_CMD_IAQ_MEASURE;
+ data->measure_gas_signals_cmd = SGP30_CMD_MEASURE_SIGNAL;
+ data->product_id = SGP30;
+ data->baseline_len = 2;
+ data->supports_humidity_compensation = true;
+ data->iaq_defval_skip_jiffies = 15 * HZ;
+ break;
+ case SGPC3:
+ data->measure_interval_jiffies = SGPC3_MEASURE_INTERVAL_HZ * HZ;
+ data->measure_iaq_cmd = SGPC3_CMD_MEASURE_RAW;
+ data->measure_gas_signals_cmd = SGPC3_CMD_MEASURE_RAW;
+ data->product_id = SGPC3;
+ data->baseline_len = 1;
+ data->power_mode = SGPC3_POWER_MODE_LOW_POWER;
+ data->iaq_init_user_duration =
+ SGPC3_DEFAULT_IAQ_INIT_DURATION_HZ;
+ if (SGP_VERS_MAJOR(data) == 0 && SGP_VERS_MINOR(data) >= 6) {
+ data->supports_humidity_compensation = true;
+ data->supports_power_mode = true;
+ }
+ data->iaq_init_fn = &sgpc3_iaq_init;
+ break;
+ };
+ data->iaq_thread = kthread_run(sgp_iaq_threadfn, data,
+ "%s-iaq", data->client->name);
+}
+
+static IIO_DEVICE_ATTR(in_serial_id, 0444, sgp_serial_id_show, NULL, 0);
+static IIO_DEVICE_ATTR(in_feature_set_version, 0444,
+ sgp_feature_set_version_show, NULL, 0);
+static IIO_DEVICE_ATTR(in_selftest, 0444, sgp_selftest_show, NULL, 0);
+static IIO_DEVICE_ATTR(set_iaq_preheat_seconds, 0220, NULL,
+ sgp_iaq_preheat_store, 0);
+static IIO_DEVICE_ATTR(in_iaq_baseline, 0444, sgp_iaq_baseline_show, NULL, 0);
+static IIO_DEVICE_ATTR(set_iaq_baseline, 0220, NULL, sgp_iaq_baseline_store, 0);
+static IIO_DEVICE_ATTR(set_absolute_humidity, 0220, NULL,
+ sgp_absolute_humidity_store, 0);
+static IIO_DEVICE_ATTR(set_power_mode, 0220, NULL,
+ sgp_power_mode_store, 0);
+
+static struct attribute *sgp_attributes[] = {
+ &iio_dev_attr_in_serial_id.dev_attr.attr,
+ &iio_dev_attr_in_feature_set_version.dev_attr.attr,
+ &iio_dev_attr_in_selftest.dev_attr.attr,
+ &iio_dev_attr_in_iaq_baseline.dev_attr.attr,
+ &iio_dev_attr_set_iaq_baseline.dev_attr.attr,
+ &iio_dev_attr_set_iaq_preheat_seconds.dev_attr.attr,
+ &iio_dev_attr_set_absolute_humidity.dev_attr.attr,
+ &iio_dev_attr_set_power_mode.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group sgp_attr_group = {
+ .attrs = sgp_attributes,
+};
+
+static const struct iio_info sgp_info = {
+ .attrs = &sgp_attr_group,
+ .read_raw = sgp_read_raw,
+};
+
+static const struct of_device_id sgp_dt_ids[] = {
+ { .compatible = "sensirion,sgp30", .data = (void *)SGP30 },
+ { .compatible = "sensirion,sgpc3", .data = (void *)SGPC3 },
+ { }
+};
+
+static int sgp_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct iio_dev *indio_dev;
+ struct sgp_data *data;
+ const struct sgp_device *chip;
+ const struct of_device_id *of_id;
+ unsigned long product_id;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ of_id = of_match_device(sgp_dt_ids, &client->dev);
+ if (of_id)
+ product_id = (unsigned long)of_id->data;
+ else
+ product_id = id->driver_data;
+
+ chip = &sgp_devices[product_id];
+ data = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ data->client = client;
+ crc8_populate_msb(sgp_crc8_table, SGP_CRC8_POLYNOMIAL);
+ mutex_init(&data->data_lock);
+
+ /* get serial id and write it to client data */
+ ret = sgp_get_serial_id(data);
+ if (ret < 0)
+ return ret;
+
+ /* get feature set version and write it to client data */
+ ret = sgp_read_cmd(data, SGP_CMD_GET_FEATURE_SET, &data->buffer, 1,
+ SGP_CMD_DURATION_US);
+ if (ret < 0)
+ return ret;
+
+ data->feature_set = be16_to_cpu(data->buffer.raw_words[0].value);
+
+ ret = sgp_check_compat(data, product_id);
+ if (ret)
+ return ret;
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &sgp_info;
+ indio_dev->name = id->name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ indio_dev->channels = chip->channels;
+ indio_dev->num_channels = chip->num_channels;
+
+ ret = devm_iio_device_register(&client->dev, indio_dev);
+ if (ret) {
+ dev_err(&client->dev, "failed to register iio device\n");
+ return ret;
+ }
+
+ sgp_init(data);
+ return ret;
+}
+
+static int sgp_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct sgp_data *data = iio_priv(indio_dev);
+
+ if (data->iaq_thread)
+ kthread_stop(data->iaq_thread);
+ return 0;
+}
+
+static const struct i2c_device_id sgp_id[] = {
+ { "sgp30", SGP30 },
+ { "sgpc3", SGPC3 },
+ { }
+};
+
+MODULE_DEVICE_TABLE(i2c, sgp_id);
+MODULE_DEVICE_TABLE(of, sgp_dt_ids);
+
+static struct i2c_driver sgp_driver = {
+ .driver = {
+ .name = "sgp30",
+ .of_match_table = of_match_ptr(sgp_dt_ids),
+ },
+ .probe = sgp_probe,
+ .remove = sgp_remove,
+ .id_table = sgp_id,
+};
+module_i2c_driver(sgp_driver);
+
+MODULE_AUTHOR("Andreas Brauchli <andreas.brauchli@...sirion.com>");
+MODULE_AUTHOR("Pascal Sachs <pascal.sachs@...sirion.com>");
+MODULE_DESCRIPTION("Sensirion SGP gas sensors");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION("0.6.0");
--
2.15.1
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