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Subject[PATCH v2 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 | 20 +
MAINTAINERS | 6 +
drivers/iio/chemical/Kconfig | 11 +
drivers/iio/chemical/Makefile | 1 +
drivers/iio/chemical/scd30.h | 75 ++
drivers/iio/chemical/scd30_core.c | 764 ++++++++++++++++++
6 files changed, 877 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..a05b1d28e94a
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-scd30
@@ -0,0 +1,20 @@
+What: /sys/bus/iio/devices/iio:deviceX/calibration
+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 either automatic
+ self calibration (asc) or forced recalibration (frc). If used
+ at once one will overwrite the other.
+
+ Writing 1 or 0 to this attribute will respectively activate or
+ deactivate asc.
+
+ Picking value from the range [400 1 2000] and writing it to the
+ sensor will set frc.
+
+ Upon reading current asc status and frc value are returned
+ respectively.
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..9b25f7423142
--- /dev/null
+++ b/drivers/iio/chemical/scd30.h
@@ -0,0 +1,75 @@
+/* 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;
+ 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..3b7d0a7ea7ae
--- /dev/null
+++ b/drivers/iio/chemical/scd30_core.c
@@ -0,0 +1,764 @@
+// 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)
+{
+ int ret;
+
+ ret = state->command(state, cmd, 0, val, sizeof(*val));
+ *val = be16_to_cpup((__be16 *)val);
+
+ 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]);
+
+ 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, meas[SCD30_MEAS_COUNT];
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ case IIO_CHAN_INFO_PROCESSED:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ mutex_lock(&state->lock);
+ ret = scd30_read(state);
+ memcpy(meas, state->meas, SCD30_MEAS_COUNT * sizeof(*meas));
+ mutex_unlock(&state->lock);
+ iio_device_release_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ switch (chan->type) {
+ case IIO_CONCENTRATION:
+ *val = meas[chan->address] / 1000000;
+ *val2 = meas[chan->address] % 1000000;
+
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_TEMP:
+ case IIO_HUMIDITYRELATIVE:
+ *val = meas[chan->address] * 10;
+
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_CONCENTRATION:
+ *val = 0;
+ *val2 = 1;
+
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_TEMP:
+ case IIO_HUMIDITYRELATIVE:
+ *val = 10;
+
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = 0;
+ *val2 = 0;
+
+ mutex_lock(&state->lock);
+ ret = scd30_command_read(state, CMD_MEAS_INTERVAL, (u16 *)val2);
+ mutex_unlock(&state->lock);
+ if (ret)
+ return ret;
+
+ *val2 = 1000000000 / *val2;
+
+ return IIO_VAL_INT_PLUS_NANO;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ mutex_lock(&state->lock);
+ *val = state->pressure_comp / 10;
+ *val2 = (state->pressure_comp % 10) * 100000;
+ mutex_unlock(&state->lock);
+
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ *val = 0;
+ mutex_lock(&state->lock);
+ ret = scd30_command_read(state, CMD_TEMP_OFFSET, (u16 *)val);
+ mutex_unlock(&state->lock);
+
+ return IIO_VAL_INT;
+ }
+
+ return -EINVAL;
+}
+
+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_RAW:
+ case IIO_CHAN_INFO_CALIBBIAS:
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ return IIO_VAL_INT_PLUS_NANO;
+ }
+
+ 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
+ * adjecent). 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_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);
+ u16 asc, frc;
+ int ret;
+
+ mutex_lock(&state->lock);
+ ret = scd30_command_read(state, CMD_ASC, &asc);
+ if (ret)
+ goto out;
+
+ ret = scd30_command_read(state, CMD_FRC, &frc);
+out:
+ mutex_unlock(&state->lock);
+
+ return ret ?: sprintf(buf, "%d %d\n", asc, frc);
+}
+
+static ssize_t calibration_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);
+ if (val == 0 || val == 1)
+ ret = scd30_command_write(state, CMD_ASC, val);
+ else if (val >= SCD30_FRC_MIN_PPM && val <= SCD30_FRC_MAX_PPM)
+ ret = scd30_command_write(state, CMD_FRC, val);
+ else
+ ret = -EINVAL;
+ mutex_unlock(&state->lock);
+
+ return ret ?: len;
+}
+
+static IIO_DEVICE_ATTR_RO(sampling_frequency_available, 0);
+static IIO_DEVICE_ATTR_RW(calibration, 0);
+
+static struct attribute *scd30_attrs[] = {
+ &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+ &iio_dev_attr_calibration.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', 16),
+ },
+ {
+ .type = IIO_TEMP,
+ .address = SCD30_TEMP,
+ .scan_index = SCD30_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+ BIT(IIO_CHAN_INFO_CALIBBIAS) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .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', 14),
+ },
+ {
+ .type = IIO_HUMIDITYRELATIVE,
+ .address = SCD30_HR,
+ .scan_index = SCD30_HR,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+
+ SCD30_CHAN_SCAN_TYPE('u', 14),
+ },
+ 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];
+ u64 ts;
+ } scan;
+ 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,
+};
+
+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");
+
+ 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 = devm_add_action_or_reset(dev, scd30_stop_meas, 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;
+ }
+
+ 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
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  Last update: 2020-05-30 23:39    [W:0.155 / U:10.856 seconds]
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