* [PATCH v6 4/4] iio: flow: add Sensirion SLF3S liquid flow sensor driver
2026-07-28 21:49 [PATCH v6 0/4] iio: flow: Sensirion SLF3S liquid flow sensor Wadim Mueller
` (2 preceding siblings ...)
2026-07-28 21:49 ` [PATCH v6 3/4] iio: core: add IIO_VAL_DECIMAL64_FEMTO format type Wadim Mueller
@ 2026-07-28 21:49 ` Wadim Mueller
3 siblings, 0 replies; 6+ messages in thread
From: Wadim Mueller @ 2026-07-28 21:49 UTC (permalink / raw)
To: jonathan.cameron, krzk+dt, robh, conor+dt, dlechner, nuno.sa,
andy, maxwell
Cc: linux-iio, devicetree, linux-kernel, marcelo.schmitt1,
455.rodrigo.alencar
Add a driver for the Sensirion SLF3S family of digital
liquid-flow sensors on I2C. Currently supported variants are
SLF3S-0600F, SLF3S-1300F and SLF3S-4000B; they share the same
register map and differ only in flow-scale factor and calibrated
measurement range. The variant (and therefore the scale) is
auto-detected from the product-information register at probe time;
a sensor reporting an unknown sub-type falls back to the variant
named in the device tree / I2C table, so a drop-in replacement part
keeps working on a kernel that does not know its sub-type yet.
Each measurement frame returns a 16-bit signed flow value, a
16-bit signed temperature reading and a status word, each
protected by a CRC-8 byte. The driver exposes the flow rate as
IIO_VOLUMEFLOW and the temperature as IIO_TEMP via the standard
IIO read_raw / read_scale interface.
The volume-flow scale is reported in m^3/s. As the per-LSB scale
is on the order of 1e-12 m^3/s, it is emitted as a 64-bit
fixed-point value with femto (1e-15) resolution
(IIO_VAL_DECIMAL64_FEMTO) so the small SI value keeps full
precision. This relies on the IIO_VAL_DECIMAL64_FEMTO format type
added earlier in this series.
The active calibration medium can be switched at runtime between
the factory-calibrated water and isopropyl-alcohol modes via the
in_volumeflow_medium sysfs attribute; the sensor starts in water
mode after probe.
The sensor has no low-power state of its own, so system suspend
stops the measurement and disables the vdd supply; resume powers
the sensor back up, waits out the power-up time and restarts the
measurement with the previously active medium, following the
scd30/scd4x precedent.
This driver also creates the drivers/iio/flow/ subdirectory and
the corresponding Kconfig/Makefile glue.
Signed-off-by: Wadim Mueller <wafgo01@gmail.com>
---
Documentation/ABI/testing/sysfs-bus-iio-flow | 21 +
MAINTAINERS | 1 +
drivers/iio/Kconfig | 1 +
drivers/iio/Makefile | 1 +
drivers/iio/flow/Kconfig | 22 +
drivers/iio/flow/Makefile | 7 +
drivers/iio/flow/slf3s.c | 543 +++++++++++++++++++
7 files changed, 596 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-flow
create mode 100644 drivers/iio/flow/Kconfig
create mode 100644 drivers/iio/flow/Makefile
create mode 100644 drivers/iio/flow/slf3s.c
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-flow b/Documentation/ABI/testing/sysfs-bus-iio-flow
new file mode 100644
index 000000000000..fece2ecfa994
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-flow
@@ -0,0 +1,21 @@
+What: /sys/bus/iio/devices/iio:deviceX/in_volumeflow_medium
+What: /sys/bus/iio/devices/iio:deviceX/in_volumeflowY_medium
+KernelVersion: 7.3
+Contact: linux-iio@vger.kernel.org
+Description:
+ The calibration medium the flow sensor uses to convert its
+ raw reading into a volumetric flow rate. Liquid flow sensors
+ are factory-calibrated per medium, so the selected medium has
+ to match the fluid actually flowing through the sensor for the
+ reported flow rate to be correct.
+
+ Reading returns the currently active medium; writing one of the
+ strings listed in in_volumeflow_medium_available selects it.
+
+What: /sys/bus/iio/devices/iio:deviceX/in_volumeflow_medium_available
+What: /sys/bus/iio/devices/iio:deviceX/in_volumeflowY_medium_available
+KernelVersion: 7.3
+Contact: linux-iio@vger.kernel.org
+Description:
+ Space separated list of the calibration media supported by the
+ device, e.g. "water ipa".
diff --git a/MAINTAINERS b/MAINTAINERS
index 497492825f70..03de8197f0a9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -24589,6 +24589,7 @@ R: Maxwell Doose <maxwell@maxwelld.cc>
L: linux-iio@vger.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/iio/flow/sensirion,slf3s.yaml
+F: drivers/iio/flow/slf3s.c
SENSIRION SPS30 AIR POLLUTION SENSOR DRIVER
M: Tomasz Duszynski <tduszyns@gmail.com>
diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index 661127aed2f9..652557a5b851 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -92,6 +92,7 @@ source "drivers/iio/common/Kconfig"
source "drivers/iio/dac/Kconfig"
source "drivers/iio/dummy/Kconfig"
source "drivers/iio/filter/Kconfig"
+source "drivers/iio/flow/Kconfig"
source "drivers/iio/frequency/Kconfig"
source "drivers/iio/gyro/Kconfig"
source "drivers/iio/health/Kconfig"
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index cb80ef837e84..f03a4100c800 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -29,6 +29,7 @@ obj-y += dac/
obj-y += dummy/
obj-y += gyro/
obj-y += filter/
+obj-y += flow/
obj-y += frequency/
obj-y += health/
obj-y += humidity/
diff --git a/drivers/iio/flow/Kconfig b/drivers/iio/flow/Kconfig
new file mode 100644
index 000000000000..e0e1a8e3654a
--- /dev/null
+++ b/drivers/iio/flow/Kconfig
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Liquid / gas flow sensor drivers
+#
+# When adding new entries keep the list in alphabetical order
+
+menu "Flow sensors"
+
+config SENSIRION_SLF3S
+ tristate "Sensirion SLF3S liquid flow sensor"
+ depends on I2C
+ select CRC8
+ help
+ Say yes here to build support for the Sensirion SLF3S family of
+ digital liquid-flow sensors (SLF3S-0600F, SLF3S-1300F and
+ SLF3S-4000B). The driver reports the volumetric flow rate and the
+ embedded temperature reading via the standard IIO interface.
+
+ To compile this driver as a module, choose M here: the module
+ will be called slf3s.
+
+endmenu
diff --git a/drivers/iio/flow/Makefile b/drivers/iio/flow/Makefile
new file mode 100644
index 000000000000..3cf4ab95c69c
--- /dev/null
+++ b/drivers/iio/flow/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for industrial I/O flow sensor drivers
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_SENSIRION_SLF3S) += slf3s.o
diff --git a/drivers/iio/flow/slf3s.c b/drivers/iio/flow/slf3s.c
new file mode 100644
index 000000000000..518ad41afc6c
--- /dev/null
+++ b/drivers/iio/flow/slf3s.c
@@ -0,0 +1,543 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sensirion SLF3S liquid flow sensor driver.
+ *
+ * Supports the SLF3S-0600F, SLF3S-1300F and SLF3S-4000B liquid-flow
+ * sensors over I2C. Each measurement frame returns a 16-bit signed
+ * flow value, a 16-bit signed temperature value and a status word,
+ * each protected by a CRC-8 byte.
+ *
+ * The active calibration medium (water or isopropyl alcohol) is
+ * runtime-switchable via the in_volumeflow_medium sysfs attribute and
+ * defaults to water.
+ *
+ * Datasheet: https://sensirion.com/products/catalog/SLF3S-0600F/
+ *
+ * Copyright (C) 2026 CMBlu Energy GmbH
+ * Author: Wadim Mueller <wafgo01@gmail.com>
+ */
+
+#include <linux/array_size.h>
+#include <linux/bitops.h>
+#include <linux/cleanup.h>
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/dev_printk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/math.h>
+#include <linux/math64.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm.h>
+#include <linux/regulator/consumer.h>
+#include <linux/types.h>
+#include <linux/unaligned.h>
+#include <linux/units.h>
+
+#include <linux/iio/iio.h>
+
+#define SLF3S_CRC8_POLY 0x31
+#define SLF3S_CRC8_INIT 0xff
+
+#define SLF3S_PRODUCT_ID_LEN 18
+#define SLF3S_PRODUCT_FAMILY_BYTE 1
+#define SLF3S_PRODUCT_SUBTYPE_BYTE 3
+#define SLF3S_PRODUCT_FAMILY_ID 0x03
+
+/* Datasheet section 2.2: tPU = 25 ms max from power-on to first cmd. */
+#define SLF3S_POWER_UP_DELAY_US (25 * USEC_PER_MSEC)
+/* Datasheet section 2.2: tw = 60 ms typical until first valid sample. */
+#define SLF3S_MEAS_START_DELAY_US (60 * USEC_PER_MSEC)
+
+static const u8 slf3s_cmd_prep_pid[] = { 0x36, 0x7c };
+static const u8 slf3s_cmd_read_pid[] = { 0xe1, 0x02 };
+static const u8 slf3s_cmd_start_water[] = { 0x36, 0x08 };
+static const u8 slf3s_cmd_start_ipa[] = { 0x36, 0x15 };
+static const u8 slf3s_cmd_stop_meas[] = { 0x3f, 0xf9 };
+
+enum slf3s_medium {
+ SLF3S_MEDIUM_WATER,
+ SLF3S_MEDIUM_IPA,
+};
+
+static const char * const slf3s_medium_modes[] = {
+ [SLF3S_MEDIUM_WATER] = "water",
+ [SLF3S_MEDIUM_IPA] = "ipa",
+};
+
+enum slf3s_variant_id {
+ SLF3S_0600F,
+ SLF3S_1300F,
+ SLF3S_4000B,
+};
+
+/**
+ * struct slf3s_variant - per-variant calibration constants
+ * @sub_type: product-info sub-type byte returned by the sensor
+ * @name: name reported via @iio_dev.name
+ * @scale: flow scale in l/s per LSB
+ */
+struct slf3s_variant {
+ u8 sub_type;
+ const char *name;
+ struct s32_fract scale;
+};
+
+static const struct slf3s_variant slf3s_variants[] = {
+ [SLF3S_0600F] = {
+ .sub_type = 0x03,
+ .name = "slf3s-0600f",
+ .scale = { .numerator = 1, .denominator = 600 * MICRO },
+ },
+ [SLF3S_1300F] = {
+ .sub_type = 0x02,
+ .name = "slf3s-1300f",
+ .scale = { .numerator = 1, .denominator = 30 * MICRO },
+ },
+ [SLF3S_4000B] = {
+ .sub_type = 0x05,
+ .name = "slf3s-4000b",
+ .scale = { .numerator = 1, .denominator = 1920 * MILLI },
+ },
+};
+
+/**
+ * struct slf3s_data - per-device state
+ * @client: I2C client this instance is bound to
+ * @vdd: supply regulator, disabled while suspended
+ * @variant: pointer into @slf3s_variants for the detected device
+ * @medium: currently active calibration medium
+ * @lock: serialises the multi-step command/response exchanges
+ * @crc_table: pre-computed CRC-8 lookup table for SLF3S_CRC8_POLY
+ */
+struct slf3s_data {
+ struct i2c_client *client;
+ struct regulator *vdd;
+ const struct slf3s_variant *variant;
+ enum slf3s_medium medium;
+ struct mutex lock;
+ u8 crc_table[CRC8_TABLE_SIZE];
+};
+
+static int slf3s_send_cmd(struct i2c_client *client, const u8 *cmd)
+{
+ int ret;
+
+ ret = i2c_master_send(client, cmd, 2);
+ if (ret < 0)
+ return ret;
+ if (ret != 2)
+ return -EIO;
+
+ return 0;
+}
+
+/* Start continuous measurement and wait until the first sample is valid. */
+static int slf3s_start_meas(struct slf3s_data *sf, enum slf3s_medium medium)
+{
+ const u8 *cmd = (medium == SLF3S_MEDIUM_IPA) ? slf3s_cmd_start_ipa
+ : slf3s_cmd_start_water;
+ int ret;
+
+ ret = slf3s_send_cmd(sf->client, cmd);
+ if (ret)
+ return ret;
+
+ fsleep(SLF3S_MEAS_START_DELAY_US);
+
+ return 0;
+}
+
+static bool slf3s_crc_valid(const struct slf3s_data *sf, const u8 *block)
+{
+ return crc8(sf->crc_table, block, 2, SLF3S_CRC8_INIT) == block[2];
+}
+
+/*
+ * Read the product-info block and pick the matching variant. The
+ * sub-type byte returned by the sensor is the source of truth; a
+ * DT-supplied compatible only seeds an initial guess and is overridden
+ * on mismatch (with an informational message so misconfigured device
+ * trees are easy to spot).
+ *
+ * Bus / CRC failures are real errors and fail probe. An unknown
+ * sub-type byte falls back to the variant named in the device tree /
+ * I2C table, so a drop-in replacement part that lists one of the known
+ * compatibles keeps working on an older kernel that does not know its
+ * sub-type yet. Without any match data probe fails since no
+ * meaningful scale can be published.
+ */
+static int slf3s_detect_variant(struct slf3s_data *sf)
+{
+ struct i2c_client *client = sf->client;
+ u8 buf[SLF3S_PRODUCT_ID_LEN];
+ int ret;
+
+ ret = slf3s_send_cmd(client, slf3s_cmd_prep_pid);
+ if (ret)
+ return ret;
+
+ ret = slf3s_send_cmd(client, slf3s_cmd_read_pid);
+ if (ret)
+ return ret;
+
+ ret = i2c_master_recv(client, buf, sizeof(buf));
+ if (ret < 0)
+ return ret;
+ if (ret != sizeof(buf))
+ return -EIO;
+
+ for (unsigned int i = 0; i < SLF3S_PRODUCT_ID_LEN; i += 3) {
+ if (!slf3s_crc_valid(sf, &buf[i]))
+ return -EIO;
+ }
+
+ if (buf[SLF3S_PRODUCT_FAMILY_BYTE] != SLF3S_PRODUCT_FAMILY_ID)
+ dev_info(&client->dev,
+ "unexpected family byte 0x%02x (expected 0x%02x)\n",
+ buf[SLF3S_PRODUCT_FAMILY_BYTE],
+ SLF3S_PRODUCT_FAMILY_ID);
+
+ for (unsigned int i = 0; i < ARRAY_SIZE(slf3s_variants); i++) {
+ if (buf[SLF3S_PRODUCT_SUBTYPE_BYTE] !=
+ slf3s_variants[i].sub_type)
+ continue;
+
+ if (sf->variant && sf->variant != &slf3s_variants[i])
+ dev_info(&client->dev,
+ "DT compatible says %s but sensor reports %s; using the latter\n",
+ sf->variant->name,
+ slf3s_variants[i].name);
+
+ sf->variant = &slf3s_variants[i];
+
+ return 0;
+ }
+
+ if (sf->variant) {
+ dev_warn(&client->dev,
+ "unknown SLF3S sub-type 0x%02x, assuming %s\n",
+ buf[SLF3S_PRODUCT_SUBTYPE_BYTE], sf->variant->name);
+ return 0;
+ }
+
+ dev_err(&client->dev, "unknown SLF3S sub-type 0x%02x\n",
+ buf[SLF3S_PRODUCT_SUBTYPE_BYTE]);
+
+ return -ENODEV;
+}
+
+static int slf3s_read_sample(struct slf3s_data *sf, int *flow, int *temp)
+{
+ /*
+ * A measurement frame is flow, temperature and a signaling-flags
+ * word, each followed by a CRC byte. Only flow and temperature are
+ * used, so the read is stopped after their two words (6 bytes).
+ */
+ u8 buf[6];
+ int ret;
+
+ ret = i2c_master_recv(sf->client, buf, sizeof(buf));
+ if (ret < 0)
+ return ret;
+ if (ret != sizeof(buf))
+ return -EIO;
+
+ for (unsigned int i = 0; i < sizeof(buf); i += 3) {
+ if (!slf3s_crc_valid(sf, &buf[i]))
+ return -EIO;
+ }
+
+ *flow = sign_extend32(get_unaligned_be16(&buf[0]), 15);
+ *temp = sign_extend32(get_unaligned_be16(&buf[3]), 15);
+
+ return 0;
+}
+
+static int slf3s_get_medium(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct slf3s_data *sf = iio_priv(indio_dev);
+
+ return sf->medium;
+}
+
+static int slf3s_set_medium(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, unsigned int mode)
+{
+ struct slf3s_data *sf = iio_priv(indio_dev);
+ int ret;
+
+ guard(mutex)(&sf->lock);
+
+ ret = slf3s_send_cmd(sf->client, slf3s_cmd_stop_meas);
+ if (ret)
+ return ret;
+
+ ret = slf3s_start_meas(sf, mode);
+ if (ret) {
+ /*
+ * Try to restart with the previous medium so the sensor is
+ * not left idle, which would fail all subsequent reads.
+ */
+ if (slf3s_start_meas(sf, sf->medium))
+ dev_warn(&sf->client->dev,
+ "failed to restart measurement, reads will fail until a medium is set\n");
+ return ret;
+ }
+
+ sf->medium = mode;
+
+ return 0;
+}
+
+static const struct iio_enum slf3s_medium_enum = {
+ .items = slf3s_medium_modes,
+ .num_items = ARRAY_SIZE(slf3s_medium_modes),
+ .get = slf3s_get_medium,
+ .set = slf3s_set_medium,
+};
+
+static const struct iio_chan_spec_ext_info slf3s_ext_info[] = {
+ IIO_ENUM("medium", IIO_SHARED_BY_TYPE, &slf3s_medium_enum),
+ IIO_ENUM_AVAILABLE("medium", IIO_SHARED_BY_TYPE, &slf3s_medium_enum),
+ { }
+};
+
+static const struct iio_chan_spec slf3s_channels[] = {
+ {
+ .type = IIO_VOLUMEFLOW,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .ext_info = slf3s_ext_info,
+ },
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ },
+};
+
+static int slf3s_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct slf3s_data *sf = iio_priv(indio_dev);
+ int flow, temp, ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ scoped_guard(mutex, &sf->lock)
+ ret = slf3s_read_sample(sf, &flow, &temp);
+ if (ret)
+ return ret;
+
+ *val = (chan->type == IIO_VOLUMEFLOW) ? flow : temp;
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ if (chan->type == IIO_VOLUMEFLOW) {
+ /*
+ * The variant scale is the flow per LSB in l/s, but
+ * IIO reports volume flow in m^3/s (1 l = 1e-3 m^3).
+ * These values are tiny (~1.67e-12 m^3/s for the
+ * SLF3S-0600F), so emit a 64-bit fixed-point value with
+ * femto (1e-15) resolution to preserve precision.
+ * Converting l/s to m^3/s (/ MILLI) and scaling to femto
+ * (* FEMTO) leaves a net * (FEMTO / MILLI) factor.
+ */
+ const struct slf3s_variant *v = sf->variant;
+ s64 num = (s64)v->scale.numerator * (FEMTO / MILLI);
+ s64 scale = DIV_S64_ROUND_CLOSEST(num,
+ v->scale.denominator);
+
+ iio_val_s64_decompose(scale, val, val2);
+
+ return IIO_VAL_DECIMAL64_FEMTO;
+ }
+ /* Temperature LSB = 1/200 degC; IIO_TEMP wants milli-degC. */
+ *val = MILLIDEGREE_PER_DEGREE / 200;
+
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info slf3s_info = {
+ .read_raw = slf3s_read_raw,
+};
+
+static void slf3s_stop_meas(void *data)
+{
+ struct slf3s_data *sf = data;
+
+ slf3s_send_cmd(sf->client, slf3s_cmd_stop_meas);
+}
+
+static void slf3s_disable_vdd(void *data)
+{
+ struct slf3s_data *sf = data;
+
+ regulator_disable(sf->vdd);
+}
+
+static int slf3s_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct iio_dev *indio_dev;
+ struct slf3s_data *sf;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*sf));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ sf = iio_priv(indio_dev);
+ sf->client = client;
+ i2c_set_clientdata(client, indio_dev);
+ sf->variant = i2c_get_match_data(client);
+ sf->medium = SLF3S_MEDIUM_WATER;
+ crc8_populate_msb(sf->crc_table, SLF3S_CRC8_POLY);
+
+ ret = devm_mutex_init(dev, &sf->lock);
+ if (ret)
+ return ret;
+
+ sf->vdd = devm_regulator_get(dev, "vdd");
+ if (IS_ERR(sf->vdd))
+ return dev_err_probe(dev, PTR_ERR(sf->vdd),
+ "failed to get vdd supply\n");
+
+ ret = regulator_enable(sf->vdd);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to enable vdd supply\n");
+
+ ret = devm_add_action_or_reset(dev, slf3s_disable_vdd, sf);
+ if (ret)
+ return ret;
+
+ fsleep(SLF3S_POWER_UP_DELAY_US);
+
+ /*
+ * The sensor may still be in continuous measurement mode from a
+ * previous boot (warm reboot / kexec); in that case it would NACK
+ * the product-id command below. Stop it first and ignore the error
+ * if it was already idle.
+ */
+ slf3s_send_cmd(client, slf3s_cmd_stop_meas);
+
+ ret = slf3s_detect_variant(sf);
+ if (ret)
+ return dev_err_probe(dev, ret, "product info read failed\n");
+
+ ret = slf3s_start_meas(sf, sf->medium);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "failed to start measurement\n");
+
+ ret = devm_add_action_or_reset(dev, slf3s_stop_meas, sf);
+ if (ret)
+ return ret;
+
+ indio_dev->name = sf->variant->name;
+ indio_dev->channels = slf3s_channels;
+ indio_dev->num_channels = ARRAY_SIZE(slf3s_channels);
+ indio_dev->info = &slf3s_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+/*
+ * The sensor has no low-power state of its own, so stop the measurement
+ * and cut the supply while suspended. Resume powers it back up, waits
+ * out the power-up time and restarts with the medium that was active
+ * before.
+ */
+static int slf3s_suspend(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct slf3s_data *sf = iio_priv(indio_dev);
+ int ret;
+
+ guard(mutex)(&sf->lock);
+
+ ret = slf3s_send_cmd(sf->client, slf3s_cmd_stop_meas);
+ if (ret)
+ return ret;
+
+ return regulator_disable(sf->vdd);
+}
+
+static int slf3s_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct slf3s_data *sf = iio_priv(indio_dev);
+ int ret;
+
+ guard(mutex)(&sf->lock);
+
+ ret = regulator_enable(sf->vdd);
+ if (ret)
+ return ret;
+
+ fsleep(SLF3S_POWER_UP_DELAY_US);
+
+ return slf3s_start_meas(sf, sf->medium);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(slf3s_pm_ops, slf3s_suspend, slf3s_resume);
+
+static const struct i2c_device_id slf3s_id[] = {
+ {
+ .name = "slf3s-0600f",
+ .driver_data = (kernel_ulong_t)&slf3s_variants[SLF3S_0600F],
+ },
+ {
+ .name = "slf3s-1300f",
+ .driver_data = (kernel_ulong_t)&slf3s_variants[SLF3S_1300F],
+ },
+ {
+ .name = "slf3s-4000b",
+ .driver_data = (kernel_ulong_t)&slf3s_variants[SLF3S_4000B],
+ },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, slf3s_id);
+
+static const struct of_device_id slf3s_of_match[] = {
+ {
+ .compatible = "sensirion,slf3s-0600f",
+ .data = &slf3s_variants[SLF3S_0600F],
+ },
+ {
+ .compatible = "sensirion,slf3s-1300f",
+ .data = &slf3s_variants[SLF3S_1300F],
+ },
+ {
+ .compatible = "sensirion,slf3s-4000b",
+ .data = &slf3s_variants[SLF3S_4000B],
+ },
+ { }
+};
+MODULE_DEVICE_TABLE(of, slf3s_of_match);
+
+static struct i2c_driver slf3s_driver = {
+ .driver = {
+ .name = "slf3s",
+ .of_match_table = slf3s_of_match,
+ .pm = pm_sleep_ptr(&slf3s_pm_ops),
+ },
+ .probe = slf3s_probe,
+ .id_table = slf3s_id,
+};
+module_i2c_driver(slf3s_driver);
+
+MODULE_AUTHOR("Wadim Mueller <wafgo01@gmail.com>");
+MODULE_DESCRIPTION("Sensirion SLF3S liquid flow sensor driver");
+MODULE_LICENSE("GPL");
--
2.52.0
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