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    Subject[PATCH v3 1/4] iio: chemical: scd30: add core driver
    Date
    Add Sensirion SCD30 carbon dioxide core driver.

    Signed-off-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
    ---
    Documentation/ABI/testing/sysfs-bus-iio-scd30 | 34 +
    MAINTAINERS | 6 +
    drivers/iio/chemical/Kconfig | 11 +
    drivers/iio/chemical/Makefile | 1 +
    drivers/iio/chemical/scd30.h | 80 ++
    drivers/iio/chemical/scd30_core.c | 783 ++++++++++++++++++
    6 files changed, 915 insertions(+)
    create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-scd30
    create mode 100644 drivers/iio/chemical/scd30.h
    create mode 100644 drivers/iio/chemical/scd30_core.c

    diff --git a/Documentation/ABI/testing/sysfs-bus-iio-scd30 b/Documentation/ABI/testing/sysfs-bus-iio-scd30
    new file mode 100644
    index 000000000000..b9712f390bec
    --- /dev/null
    +++ b/Documentation/ABI/testing/sysfs-bus-iio-scd30
    @@ -0,0 +1,34 @@
    +What: /sys/bus/iio/devices/iio:deviceX/calibration_auto_enable
    +Date: June 2020
    +KernelVersion: 5.8
    +Contact: linux-iio@vger.kernel.org
    +Description:
    + Contaminants build-up in the measurement chamber or optical
    + elements deterioration leads to sensor drift.
    +
    + One can compensate for sensor drift by using automatic self
    + calibration procedure (asc).
    +
    + Writing 1 or 0 to this attribute will respectively activate or
    + deactivate asc.
    +
    + Upon reading current asc status is returned.
    +
    +What: /sys/bus/iio/devices/iio:deviceX/calibration_forced_value
    +Date: June 2020
    +KernelVersion: 5.8
    +Contact: linux-iio@vger.kernel.org
    +Description:
    + Contaminants build-up in the measurement chamber or optical
    + elements deterioration leads to sensor drift.
    +
    + One can compensate for sensor drift by using forced
    + recalibration (frc). This is useful in case there's known
    + co2 reference available nearby the sensor.
    +
    + Picking value from the range [400 1 2000] and writing it to the
    + sensor will set frc.
    +
    + Upon reading current frc value is returned. Note that after
    + power cycling default value (i.e 400) is returned even though
    + internally sensor had recalibrated itself.
    diff --git a/MAINTAINERS b/MAINTAINERS
    index 60ed2963efaa..41a509cca6f1 100644
    --- a/MAINTAINERS
    +++ b/MAINTAINERS
    @@ -15137,6 +15137,12 @@ S: Maintained
    F: drivers/misc/phantom.c
    F: include/uapi/linux/phantom.h

    +SENSIRION SCD30 CARBON DIOXIDE SENSOR DRIVER
    +M: Tomasz Duszynski <tomasz.duszynski@octakon.com>
    +S: Maintained
    +F: drivers/iio/chemical/scd30.h
    +F: drivers/iio/chemical/scd30_core.c
    +
    SENSIRION SPS30 AIR POLLUTION SENSOR DRIVER
    M: Tomasz Duszynski <tduszyns@gmail.com>
    S: Maintained
    diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
    index 7f21afd73b1c..99e852b67e55 100644
    --- a/drivers/iio/chemical/Kconfig
    +++ b/drivers/iio/chemical/Kconfig
    @@ -85,6 +85,17 @@ config PMS7003
    To compile this driver as a module, choose M here: the module will
    be called pms7003.

    +config SCD30_CORE
    + tristate "SCD30 carbon dioxide sensor driver"
    + select IIO_BUFFER
    + select IIO_TRIGGERED_BUFFER
    + help
    + Say Y here to build support for the Sensirion SCD30 sensor with carbon
    + dioxide, relative humidity and temperature sensing capabilities.
    +
    + To compile this driver as a module, choose M here: the module will
    + be called scd30_core.
    +
    config SENSIRION_SGP30
    tristate "Sensirion SGPxx gas sensors"
    depends on I2C
    diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
    index aba4167db745..c9804b041ecd 100644
    --- a/drivers/iio/chemical/Makefile
    +++ b/drivers/iio/chemical/Makefile
    @@ -12,6 +12,7 @@ obj-$(CONFIG_BME680_SPI) += bme680_spi.o
    obj-$(CONFIG_CCS811) += ccs811.o
    obj-$(CONFIG_IAQCORE) += ams-iaq-core.o
    obj-$(CONFIG_PMS7003) += pms7003.o
    +obj-$(CONFIG_SCD30_CORE) += scd30_core.o
    obj-$(CONFIG_SENSIRION_SGP30) += sgp30.o
    obj-$(CONFIG_SPS30) += sps30.o
    obj-$(CONFIG_VZ89X) += vz89x.o
    diff --git a/drivers/iio/chemical/scd30.h b/drivers/iio/chemical/scd30.h
    new file mode 100644
    index 000000000000..38dcf5647d7f
    --- /dev/null
    +++ b/drivers/iio/chemical/scd30.h
    @@ -0,0 +1,80 @@
    +/* SPDX-License-Identifier: GPL-2.0 */
    +#ifndef _SCD30_H
    +#define _SCD30_H
    +
    +#include <linux/completion.h>
    +#include <linux/device.h>
    +#include <linux/mutex.h>
    +#include <linux/pm.h>
    +#include <linux/regulator/consumer.h>
    +#include <linux/types.h>
    +
    +struct scd30_state;
    +
    +enum scd30_cmd {
    + /* start continuous measurement with pressure compensation */
    + CMD_START_MEAS,
    + /* stop continuous measurement */
    + CMD_STOP_MEAS,
    + /* set/get measurement interval */
    + CMD_MEAS_INTERVAL,
    + /* check whether new measurement is ready */
    + CMD_MEAS_READY,
    + /* get measurement */
    + CMD_READ_MEAS,
    + /* turn on/off automatic self calibration */
    + CMD_ASC,
    + /* set/get forced recalibration value */
    + CMD_FRC,
    + /* set/get temperature offset */
    + CMD_TEMP_OFFSET,
    + /* get firmware version */
    + CMD_FW_VERSION,
    + /* reset sensor */
    + CMD_RESET,
    + /*
    + * Command for altitude compensation was omitted intentionally because
    + * the same can be achieved by means of CMD_START_MEAS which takes
    + * pressure above the sea level as an argument.
    + */
    +};
    +
    +#define SCD30_MEAS_COUNT 3
    +
    +typedef int (*scd30_command_t)(struct scd30_state *state, enum scd30_cmd cmd,
    + u16 arg, void *response, int size);
    +
    +struct scd30_state {
    + /* serialize access to the device */
    + struct mutex lock;
    + struct device *dev;
    + struct regulator *vdd;
    + struct completion meas_ready;
    + /*
    + * priv pointer is solely for serdev driver private data. We keep it
    + * here because driver_data inside dev has been already used for iio and
    + * struct serdev_device doesn't have one.
    + */
    + void *priv;
    + int irq;
    + /*
    + * no way to retrieve current ambient pressure compensation value from
    + * the sensor so keep one around
    + */
    + u16 pressure_comp;
    + u16 meas_interval;
    + int meas[SCD30_MEAS_COUNT];
    +
    + scd30_command_t command;
    +};
    +
    +int scd30_suspend(struct device *dev);
    +int scd30_resume(struct device *dev);
    +
    +static __maybe_unused SIMPLE_DEV_PM_OPS(scd30_pm_ops, scd30_suspend,
    + scd30_resume);
    +
    +int scd30_probe(struct device *dev, int irq, const char *name, void *priv,
    + scd30_command_t command);
    +
    +#endif
    diff --git a/drivers/iio/chemical/scd30_core.c b/drivers/iio/chemical/scd30_core.c
    new file mode 100644
    index 000000000000..a41a09e7a513
    --- /dev/null
    +++ b/drivers/iio/chemical/scd30_core.c
    @@ -0,0 +1,783 @@
    +// SPDX-License-Identifier: GPL-2.0
    +/*
    + * Sensirion SCD30 carbon dioxide sensor core driver
    + *
    + * Copyright (c) 2020 Tomasz Duszynski <tomasz.duszynski@octakon.com>
    + */
    +#include <linux/bits.h>
    +#include <linux/completion.h>
    +#include <linux/delay.h>
    +#include <linux/device.h>
    +#include <linux/errno.h>
    +#include <linux/export.h>
    +#include <linux/iio/buffer.h>
    +#include <linux/iio/iio.h>
    +#include <linux/iio/sysfs.h>
    +#include <linux/iio/trigger.h>
    +#include <linux/iio/trigger_consumer.h>
    +#include <linux/iio/triggered_buffer.h>
    +#include <linux/iio/types.h>
    +#include <linux/interrupt.h>
    +#include <linux/irqreturn.h>
    +#include <linux/jiffies.h>
    +#include <linux/kernel.h>
    +#include <linux/module.h>
    +#include <linux/mutex.h>
    +#include <linux/regulator/consumer.h>
    +#include <linux/string.h>
    +#include <linux/sysfs.h>
    +#include <linux/types.h>
    +#include <asm/byteorder.h>
    +
    +#include "scd30.h"
    +
    +#define SCD30_PRESSURE_COMP_MIN_MBAR 700
    +#define SCD30_PRESSURE_COMP_MAX_MBAR 1400
    +#define SCD30_PRESSURE_COMP_DEFAULT 1013
    +#define SCD30_MEAS_INTERVAL_MIN_S 2
    +#define SCD30_MEAS_INTERVAL_MAX_S 1800
    +#define SCD30_MEAS_INTERVAL_DEFAULT SCD30_MEAS_INTERVAL_MIN_S
    +#define SCD30_FRC_MIN_PPM 400
    +#define SCD30_FRC_MAX_PPM 2000
    +#define SCD30_TEMP_OFFSET_MAX 655360
    +#define SCD30_EXTRA_TIMEOUT_PER_S 250
    +
    +enum {
    + SCD30_CONC,
    + SCD30_TEMP,
    + SCD30_HR,
    +};
    +
    +static int scd30_command_write(struct scd30_state *state, enum scd30_cmd cmd,
    + u16 arg)
    +{
    + return state->command(state, cmd, arg, NULL, 0);
    +}
    +
    +static int scd30_command_read(struct scd30_state *state, enum scd30_cmd cmd,
    + u16 *val)
    +{
    + __be16 tmp;
    + int ret;
    +
    + ret = state->command(state, cmd, 0, &tmp, sizeof(tmp));
    + *val = be16_to_cpup(&tmp);
    +
    + return ret;
    +}
    +
    +static int scd30_reset(struct scd30_state *state)
    +{
    + int ret;
    + u16 val;
    +
    + ret = scd30_command_write(state, CMD_RESET, 0);
    + if (ret)
    + return ret;
    +
    + /* sensor boots up within 2 secs */
    + msleep(2000);
    + /*
    + * Power-on-reset causes sensor to produce some glitch on i2c bus and
    + * some controllers end up in error state. Try to recover by placing
    + * any data on the bus.
    + */
    + scd30_command_read(state, CMD_MEAS_READY, &val);
    +
    + return 0;
    +}
    +
    +/* simplified float to fixed point conversion with a scaling factor of 0.01 */
    +static int scd30_float_to_fp(int float32)
    +{
    + int fraction, shift,
    + mantissa = float32 & GENMASK(22, 0),
    + sign = float32 & BIT(31) ? -1 : 1,
    + exp = (float32 & ~BIT(31)) >> 23;
    +
    + /* special case 0 */
    + if (!exp && !mantissa)
    + return 0;
    +
    + exp -= 127;
    + if (exp < 0) {
    + exp = -exp;
    + /* return values ranging from 1 to 99 */
    + return sign * ((((BIT(23) + mantissa) * 100) >> 23) >> exp);
    + }
    +
    + /* return values starting at 100 */
    + shift = 23 - exp;
    + float32 = BIT(exp) + (mantissa >> shift);
    + fraction = mantissa & GENMASK(shift - 1, 0);
    +
    + return sign * (float32 * 100 + ((fraction * 100) >> shift));
    +}
    +
    +static int scd30_read_meas(struct scd30_state *state)
    +{
    + int i, ret;
    +
    + ret = state->command(state, CMD_READ_MEAS, 0, state->meas,
    + sizeof(state->meas));
    + if (ret)
    + return ret;
    +
    + be32_to_cpu_array(state->meas, state->meas, ARRAY_SIZE(state->meas));
    +
    + for (i = 0; i < ARRAY_SIZE(state->meas); i++)
    + state->meas[i] = scd30_float_to_fp(state->meas[i]);
    +
    + /*
    + * co2 is left unprocessed while temperature and humidity are scaled
    + * to milli deg C and milli percent respectively.
    + */
    + state->meas[SCD30_TEMP] *= 10;
    + state->meas[SCD30_HR] *= 10;
    +
    + return 0;
    +}
    +
    +static int scd30_wait_meas_irq(struct scd30_state *state)
    +{
    + int ret, timeout;
    +
    + timeout = state->meas_interval * (1000 + SCD30_EXTRA_TIMEOUT_PER_S);
    + timeout = msecs_to_jiffies(timeout);
    + reinit_completion(&state->meas_ready);
    + enable_irq(state->irq);
    + ret = wait_for_completion_interruptible_timeout(&state->meas_ready,
    + timeout);
    + if (ret > 0)
    + ret = 0;
    + else if (!ret)
    + ret = -ETIMEDOUT;
    +
    + disable_irq(state->irq);
    +
    + return ret;
    +}
    +
    +static int scd30_wait_meas_poll(struct scd30_state *state)
    +{
    + int timeout = state->meas_interval * SCD30_EXTRA_TIMEOUT_PER_S;
    + int tries = 5;
    +
    + do {
    + int ret;
    + u16 val;
    +
    + ret = scd30_command_read(state, CMD_MEAS_READY, &val);
    + if (ret)
    + return -EIO;
    +
    + /* new measurement available */
    + if (val)
    + break;
    +
    + msleep_interruptible(timeout);
    + } while (--tries);
    +
    + return tries ? 0 : -ETIMEDOUT;
    +}
    +
    +static int scd30_read_poll(struct scd30_state *state)
    +{
    + int ret;
    +
    + ret = scd30_wait_meas_poll(state);
    + if (ret)
    + return ret;
    +
    + return scd30_read_meas(state);
    +}
    +
    +static int scd30_read(struct scd30_state *state)
    +{
    + if (state->irq > 0)
    + return scd30_wait_meas_irq(state);
    +
    + return scd30_read_poll(state);
    +}
    +
    +static int scd30_read_raw(struct iio_dev *indio_dev,
    + struct iio_chan_spec const *chan,
    + int *val, int *val2, long mask)
    +{
    + struct scd30_state *state = iio_priv(indio_dev);
    + int ret = -EINVAL;
    + u16 tmp;
    +
    + mutex_lock(&state->lock);
    + switch (mask) {
    + case IIO_CHAN_INFO_RAW:
    + case IIO_CHAN_INFO_PROCESSED:
    + ret = iio_device_claim_direct_mode(indio_dev);
    + if (ret)
    + break;
    +
    + ret = scd30_read(state);
    + if (ret) {
    + iio_device_release_direct_mode(indio_dev);
    + break;
    + }
    +
    + *val = state->meas[chan->address];
    + iio_device_release_direct_mode(indio_dev);
    + ret = IIO_VAL_INT;
    + break;
    + case IIO_CHAN_INFO_SCALE:
    + *val = 0;
    + *val2 = 1;
    + ret = IIO_VAL_INT_PLUS_MICRO;
    + break;
    + case IIO_CHAN_INFO_SAMP_FREQ:
    + ret = scd30_command_read(state, CMD_MEAS_INTERVAL, &tmp);
    + if (ret)
    + break;
    +
    + *val = 0;
    + *val2 = 1000000000 / tmp;
    + ret = IIO_VAL_INT_PLUS_NANO;
    + break;
    + case IIO_CHAN_INFO_CALIBSCALE:
    + *val = state->pressure_comp / 10;
    + *val2 = (state->pressure_comp % 10) * 100000;
    + ret = IIO_VAL_INT_PLUS_MICRO;
    + break;
    + case IIO_CHAN_INFO_CALIBBIAS:
    + ret = scd30_command_read(state, CMD_TEMP_OFFSET, &tmp);
    + if (ret)
    + break;
    +
    + *val = tmp;
    + ret = IIO_VAL_INT;
    + break;
    + }
    + mutex_unlock(&state->lock);
    +
    + return ret;
    +}
    +
    +static int scd30_write_raw(struct iio_dev *indio_dev,
    + struct iio_chan_spec const *chan,
    + int val, int val2, long mask)
    +{
    + struct scd30_state *state = iio_priv(indio_dev);
    + int ret = -EINVAL;
    +
    + mutex_lock(&state->lock);
    + switch (mask) {
    + case IIO_CHAN_INFO_SAMP_FREQ:
    + if (val)
    + break;
    +
    + val = 1000000000 / val2;
    + if (val < SCD30_MEAS_INTERVAL_MIN_S ||
    + val > SCD30_MEAS_INTERVAL_MAX_S)
    + break;
    +
    + ret = scd30_command_write(state, CMD_MEAS_INTERVAL, val);
    + if (ret)
    + break;
    +
    + state->meas_interval = val;
    + break;
    + case IIO_CHAN_INFO_CALIBSCALE:
    + val = (val * 1000000 + val2) / 100000;
    + if (val < SCD30_PRESSURE_COMP_MIN_MBAR ||
    + val > SCD30_PRESSURE_COMP_MAX_MBAR)
    + break;
    +
    + ret = scd30_command_write(state, CMD_START_MEAS, val);
    + if (ret)
    + break;
    +
    + state->pressure_comp = val;
    + break;
    + case IIO_CHAN_INFO_CALIBBIAS:
    + if (val < 0 || val > SCD30_TEMP_OFFSET_MAX)
    + break;
    + /*
    + * Manufacturer does not explicitly specify min/max sensible
    + * values hence check is omitted for simplicity.
    + */
    + ret = scd30_command_write(state, CMD_TEMP_OFFSET / 10, val);
    + }
    + mutex_unlock(&state->lock);
    +
    + return ret;
    +}
    +
    +static int scd30_write_raw_get_fmt(struct iio_dev *indio_dev,
    + struct iio_chan_spec const *chan, long mask)
    +{
    + switch (mask) {
    + case IIO_CHAN_INFO_SAMP_FREQ:
    + return IIO_VAL_INT_PLUS_NANO;
    + case IIO_CHAN_INFO_CALIBSCALE:
    + return IIO_VAL_INT_PLUS_MICRO;
    + case IIO_CHAN_INFO_CALIBBIAS:
    + return IIO_VAL_INT;
    + }
    +
    + return -EINVAL;
    +}
    +
    +static const int scd30_pressure_calibscale_available[] = {
    + SCD30_PRESSURE_COMP_MIN_MBAR / 10, 0,
    + 0, 100000,
    + SCD30_PRESSURE_COMP_MAX_MBAR / 10, 0,
    +};
    +
    +static const int scd30_temp_calibbias_available[] = {
    + 0, 10, SCD30_TEMP_OFFSET_MAX,
    +};
    +
    +static int scd30_read_avail(struct iio_dev *indio_dev,
    + struct iio_chan_spec const *chan, const int **vals,
    + int *type, int *length, long mask)
    +{
    + switch (mask) {
    + case IIO_CHAN_INFO_CALIBSCALE:
    + *vals = scd30_pressure_calibscale_available;
    + *type = IIO_VAL_INT_PLUS_MICRO;
    +
    + return IIO_AVAIL_RANGE;
    + case IIO_CHAN_INFO_CALIBBIAS:
    + *vals = scd30_temp_calibbias_available;
    + *type = IIO_VAL_INT;
    +
    + return IIO_AVAIL_RANGE;
    + }
    +
    + return -EINVAL;
    +}
    +
    +static ssize_t sampling_frequency_available_show(struct device *dev,
    + struct device_attribute *attr,
    + char *buf)
    +{
    + int i = SCD30_MEAS_INTERVAL_MIN_S;
    + ssize_t len = 0;
    +
    + do {
    + len += scnprintf(buf + len, PAGE_SIZE - len, "0.%09u ",
    + 1000000000 / i);
    + /*
    + * Not all values fit PAGE_SIZE buffer hence print every 6th
    + * (each frequency differs by 6s in time domain from the
    + * adjacent). Unlisted but valid ones are still accepted.
    + */
    + i += 6;
    + } while (i <= SCD30_MEAS_INTERVAL_MAX_S);
    +
    + buf[len - 1] = '\n';
    +
    + return len;
    +}
    +
    +static ssize_t calibration_auto_enable_show(struct device *dev,
    + struct device_attribute *attr,
    + char *buf)
    +{
    + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
    + struct scd30_state *state = iio_priv(indio_dev);
    + int ret;
    + u16 val;
    +
    + mutex_lock(&state->lock);
    + ret = scd30_command_read(state, CMD_ASC, &val);
    + mutex_unlock(&state->lock);
    +
    + return ret ?: sprintf(buf, "%d\n", val);
    +}
    +
    +static ssize_t calibration_auto_enable_store(struct device *dev,
    + struct device_attribute *attr,
    + const char *buf, size_t len)
    +{
    + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
    + struct scd30_state *state = iio_priv(indio_dev);
    + int ret;
    + u16 val;
    +
    + ret = kstrtou16(buf, 0, &val);
    + if (ret)
    + return ret;
    +
    + mutex_lock(&state->lock);
    + ret = scd30_command_write(state, CMD_ASC, !!val);
    + mutex_unlock(&state->lock);
    +
    + return ret ?: len;
    +}
    +
    +static ssize_t calibration_forced_value_show(struct device *dev,
    + struct device_attribute *attr,
    + char *buf)
    +{
    + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
    + struct scd30_state *state = iio_priv(indio_dev);
    + int ret;
    + u16 val;
    +
    + mutex_lock(&state->lock);
    + ret = scd30_command_read(state, CMD_FRC, &val);
    + mutex_unlock(&state->lock);
    +
    + return ret ?: sprintf(buf, "%d\n", val);
    +}
    +
    +static ssize_t calibration_forced_value_store(struct device *dev,
    + struct device_attribute *attr,
    + const char *buf, size_t len)
    +{
    + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
    + struct scd30_state *state = iio_priv(indio_dev);
    + int ret;
    + u16 val;
    +
    + ret = kstrtou16(buf, 0, &val);
    + if (ret)
    + return ret;
    +
    + if (val < SCD30_FRC_MIN_PPM || val > SCD30_FRC_MAX_PPM)
    + return -EINVAL;
    +
    + mutex_lock(&state->lock);
    + ret = scd30_command_write(state, CMD_FRC, val);
    + mutex_unlock(&state->lock);
    +
    + return ret ?: len;
    +}
    +
    +static IIO_DEVICE_ATTR_RO(sampling_frequency_available, 0);
    +static IIO_DEVICE_ATTR_RW(calibration_auto_enable, 0);
    +static IIO_DEVICE_ATTR_RW(calibration_forced_value, 0);
    +
    +static struct attribute *scd30_attrs[] = {
    + &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
    + &iio_dev_attr_calibration_auto_enable.dev_attr.attr,
    + &iio_dev_attr_calibration_forced_value.dev_attr.attr,
    + NULL
    +};
    +
    +static const struct attribute_group scd30_attr_group = {
    + .attrs = scd30_attrs,
    +};
    +
    +static const struct iio_info scd30_info = {
    + .attrs = &scd30_attr_group,
    + .read_raw = scd30_read_raw,
    + .write_raw = scd30_write_raw,
    + .write_raw_get_fmt = scd30_write_raw_get_fmt,
    + .read_avail = scd30_read_avail,
    +};
    +
    +#define SCD30_CHAN_SCAN_TYPE(_sign, _realbits) .scan_type = { \
    + .sign = _sign, \
    + .realbits = _realbits, \
    + .storagebits = 32, \
    + .endianness = IIO_CPU, \
    +}
    +
    +static const struct iio_chan_spec scd30_channels[] = {
    + {
    + .type = IIO_PRESSURE,
    + .info_mask_separate = BIT(IIO_CHAN_INFO_CALIBSCALE),
    + .info_mask_separate_available = BIT(IIO_CHAN_INFO_CALIBSCALE),
    + .scan_index = -1,
    + },
    + {
    + .type = IIO_CONCENTRATION,
    + .channel2 = IIO_MOD_CO2,
    + .address = SCD30_CONC,
    + .scan_index = SCD30_CONC,
    + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
    + BIT(IIO_CHAN_INFO_SCALE),
    + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
    + .modified = 1,
    +
    + SCD30_CHAN_SCAN_TYPE('u', 20),
    + },
    + {
    + .type = IIO_TEMP,
    + .address = SCD30_TEMP,
    + .scan_index = SCD30_TEMP,
    + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
    + BIT(IIO_CHAN_INFO_CALIBBIAS),
    + .info_mask_separate_available = BIT(IIO_CHAN_INFO_CALIBBIAS),
    + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
    +
    + SCD30_CHAN_SCAN_TYPE('s', 18),
    + },
    + {
    + .type = IIO_HUMIDITYRELATIVE,
    + .address = SCD30_HR,
    + .scan_index = SCD30_HR,
    + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
    + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
    +
    + SCD30_CHAN_SCAN_TYPE('u', 17),
    + },
    + IIO_CHAN_SOFT_TIMESTAMP(3),
    +};
    +
    +int __maybe_unused scd30_suspend(struct device *dev)
    +{
    + struct iio_dev *indio_dev = dev_get_drvdata(dev);
    + struct scd30_state *state = iio_priv(indio_dev);
    + int ret;
    +
    + ret = scd30_command_write(state, CMD_STOP_MEAS, 0);
    + if (ret)
    + return ret;
    +
    + return regulator_disable(state->vdd);
    +}
    +EXPORT_SYMBOL(scd30_suspend);
    +
    +int __maybe_unused scd30_resume(struct device *dev)
    +{
    + struct iio_dev *indio_dev = dev_get_drvdata(dev);
    + struct scd30_state *state = iio_priv(indio_dev);
    + int ret;
    +
    + ret = regulator_enable(state->vdd);
    + if (ret)
    + return ret;
    +
    + return scd30_command_write(state, CMD_START_MEAS, state->pressure_comp);
    +}
    +EXPORT_SYMBOL(scd30_resume);
    +
    +static void scd30_stop_meas(void *data)
    +{
    + struct scd30_state *state = data;
    +
    + scd30_command_write(state, CMD_STOP_MEAS, 0);
    +}
    +
    +static void scd30_disable_regulator(void *data)
    +{
    + struct scd30_state *state = data;
    +
    + regulator_disable(state->vdd);
    +}
    +
    +static irqreturn_t scd30_irq_handler(int irq, void *priv)
    +{
    + struct iio_dev *indio_dev = priv;
    +
    + if (iio_buffer_enabled(indio_dev)) {
    + iio_trigger_poll(indio_dev->trig);
    +
    + return IRQ_HANDLED;
    + }
    +
    + return IRQ_WAKE_THREAD;
    +}
    +
    +static irqreturn_t scd30_irq_thread_handler(int irq, void *priv)
    +{
    + struct iio_dev *indio_dev = priv;
    + struct scd30_state *state = iio_priv(indio_dev);
    + int ret;
    +
    + ret = scd30_read_meas(state);
    + if (ret)
    + goto out;
    +
    + complete_all(&state->meas_ready);
    +out:
    + return IRQ_HANDLED;
    +}
    +
    +static irqreturn_t scd30_trigger_handler(int irq, void *p)
    +{
    + struct iio_poll_func *pf = p;
    + struct iio_dev *indio_dev = pf->indio_dev;
    + struct scd30_state *state = iio_priv(indio_dev);
    + struct {
    + int data[SCD30_MEAS_COUNT];
    + s64 ts __aligned(8);
    + } scan = { 0, };
    + int ret;
    +
    + mutex_lock(&state->lock);
    + if (!iio_trigger_using_own(indio_dev))
    + ret = scd30_read_poll(state);
    + else
    + ret = scd30_read_meas(state);
    + memcpy(scan.data, state->meas, sizeof(state->meas));
    + mutex_unlock(&state->lock);
    + if (ret)
    + goto out;
    +
    + iio_push_to_buffers_with_timestamp(indio_dev, &scan,
    + iio_get_time_ns(indio_dev));
    +out:
    + iio_trigger_notify_done(indio_dev->trig);
    + return IRQ_HANDLED;
    +}
    +
    +static int scd30_set_trigger_state(struct iio_trigger *trig, bool state)
    +{
    + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
    + struct scd30_state *st = iio_priv(indio_dev);
    +
    + if (state)
    + enable_irq(st->irq);
    + else
    + disable_irq(st->irq);
    +
    + return 0;
    +}
    +
    +static const struct iio_trigger_ops scd30_trigger_ops = {
    + .set_trigger_state = scd30_set_trigger_state,
    + .validate_device = iio_trigger_validate_own_device,
    +};
    +
    +static int scd30_setup_trigger(struct iio_dev *indio_dev)
    +{
    + struct scd30_state *state = iio_priv(indio_dev);
    + struct device *dev = indio_dev->dev.parent;
    + struct iio_trigger *trig;
    + int ret;
    +
    + trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name,
    + indio_dev->id);
    + if (!trig) {
    + dev_err(dev, "failed to allocate trigger\n");
    + return -ENOMEM;
    + }
    +
    + trig->dev.parent = dev;
    + trig->ops = &scd30_trigger_ops;
    + iio_trigger_set_drvdata(trig, indio_dev);
    +
    + ret = devm_iio_trigger_register(dev, trig);
    + if (ret)
    + return ret;
    +
    + indio_dev->trig = iio_trigger_get(trig);
    +
    + ret = devm_request_threaded_irq(dev, state->irq, scd30_irq_handler,
    + scd30_irq_thread_handler,
    + IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
    + indio_dev->name, indio_dev);
    + if (ret)
    + dev_err(dev, "failed to request irq\n");
    +
    + /*
    + * Interrupt is enabled just before taking a fresh measurement
    + * and disabled afterwards. This means we need to disable it here
    + * to keep calls to enable/disable balanced.
    + */
    + disable_irq(state->irq);
    +
    + return ret;
    +}
    +
    +int scd30_probe(struct device *dev, int irq, const char *name, void *priv,
    + scd30_command_t command)
    +{
    + static const unsigned long scd30_scan_masks[] = { 0x07, 0x00 };
    + struct scd30_state *state;
    + struct iio_dev *indio_dev;
    + int ret;
    + u16 val;
    +
    + indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
    + if (!indio_dev)
    + return -ENOMEM;
    +
    + state = iio_priv(indio_dev);
    + state->dev = dev;
    + state->priv = priv;
    + state->irq = irq;
    + state->pressure_comp = SCD30_PRESSURE_COMP_DEFAULT;
    + state->meas_interval = SCD30_MEAS_INTERVAL_DEFAULT;
    + state->command = command;
    + mutex_init(&state->lock);
    + init_completion(&state->meas_ready);
    +
    + dev_set_drvdata(dev, indio_dev);
    +
    + indio_dev->dev.parent = dev;
    + indio_dev->info = &scd30_info;
    + indio_dev->name = name;
    + indio_dev->channels = scd30_channels;
    + indio_dev->num_channels = ARRAY_SIZE(scd30_channels);
    + indio_dev->modes = INDIO_DIRECT_MODE;
    + indio_dev->available_scan_masks = scd30_scan_masks;
    +
    + state->vdd = devm_regulator_get(dev, "vdd");
    + if (IS_ERR(state->vdd)) {
    + if (PTR_ERR(state->vdd) == -EPROBE_DEFER)
    + return -EPROBE_DEFER;
    +
    + dev_err(dev, "failed to get regulator\n");
    + return PTR_ERR(state->vdd);
    + }
    +
    + ret = regulator_enable(state->vdd);
    + if (ret)
    + return ret;
    +
    + ret = devm_add_action_or_reset(dev, scd30_disable_regulator, state);
    + if (ret)
    + return ret;
    +
    + ret = scd30_reset(state);
    + if (ret) {
    + dev_err(dev, "failed to reset device: %d\n", ret);
    + return ret;
    + }
    +
    + if (state->irq > 0) {
    + ret = scd30_setup_trigger(indio_dev);
    + if (ret) {
    + dev_err(dev, "failed to setup trigger: %d\n", ret);
    + return ret;
    + }
    + }
    +
    + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
    + scd30_trigger_handler, NULL);
    + if (ret)
    + return ret;
    +
    + ret = scd30_command_read(state, CMD_FW_VERSION, &val);
    + if (ret) {
    + dev_err(dev, "failed to read firmware version: %d\n", ret);
    + return ret;
    + }
    + dev_info(dev, "firmware version: %d.%d\n", val >> 8, (char)val);
    +
    + ret = scd30_command_write(state, CMD_MEAS_INTERVAL,
    + state->meas_interval);
    + if (ret) {
    + dev_err(dev, "failed to set measurement interval: %d\n", ret);
    + return ret;
    + }
    +
    + ret = scd30_command_write(state, CMD_START_MEAS, state->pressure_comp);
    + if (ret) {
    + dev_err(dev, "failed to start measurement: %d\n", ret);
    + return ret;
    + }
    +
    + ret = devm_add_action_or_reset(dev, scd30_stop_meas, state);
    + if (ret)
    + return ret;
    +
    + return devm_iio_device_register(dev, indio_dev);
    +}
    +EXPORT_SYMBOL(scd30_probe);
    +
    +MODULE_AUTHOR("Tomasz Duszynski <tomasz.duszynski@octakon.com>");
    +MODULE_DESCRIPTION("Sensirion SCD30 carbon dioxide sensor core driver");
    +MODULE_LICENSE("GPL v2");
    --
    2.26.2
    \
     
     \ /
      Last update: 2020-06-02 18:50    [W:2.265 / U:0.164 seconds]
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