diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index f790f1260c33..1020eadf8ab3 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -149,6 +149,7 @@ Hardware Monitoring Kernel Drivers
    nsa320
    ntc_thermistor
    nzxt-kraken2
+   nzxt-smart2
    occ
    pc87360
    pc87427
diff --git a/Documentation/hwmon/nzxt-smart2.rst b/Documentation/hwmon/nzxt-smart2.rst
new file mode 100644
index 000000000000..d9d1b2742665
--- /dev/null
+++ b/Documentation/hwmon/nzxt-smart2.rst
@@ -0,0 +1,62 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver nzxt-smart2
+=========================
+
+Supported devices:
+
+- NZXT RGB & Fan controller
+- NZXT Smart Device v2
+
+Description
+-----------
+
+This driver implements monitoring and control of fans plugged into the device.
+Besides typical speed monitoring and PWM duty cycle control, voltage and current
+is reported for every fan.
+
+The device also has two connectors for RGB LEDs; support for them isn't
+implemented (mainly because there is no standardized sysfs interface).
+
+Also, the device has a noise sensor, but the sensor seems to be completely
+useless (and very imprecise), so support for it isn't implemented too.
+
+Usage Notes
+-----------
+
+The device should be autodetected, and the driver should load automatically.
+
+If fans are plugged in/unplugged while the system is powered on, the driver
+must be reloaded to detect configuration changes; otherwise, new fans can't
+be controlled (`pwm*` changes will be ignored). It is necessary because the
+device has a dedicated "detect fans" command, and currently, it is executed only
+during initialization. Speed, voltage, current monitoring will work even without
+reload. As an alternative to reloading the module, a userspace tool (like
+`liquidctl`_) can be used to run "detect fans" command through hidraw interface.
+
+The driver coexists with userspace tools that access the device through hidraw
+interface with no known issues.
+
+.. _liquidctl: https://github.com/liquidctl/liquidctl
+
+Sysfs entries
+-------------
+
+=======================	========================================================
+fan[1-3]_input		Fan speed monitoring (in rpm).
+curr[1-3]_input		Current supplied to the fan (in milliamperes).
+in[0-2]_input		Voltage supplied to the fan (in millivolts).
+pwm[1-3]		Controls fan speed: PWM duty cycle for PWM-controlled
+			fans, voltage for other fans. Voltage can be changed in
+			9-12 V range, but the value of the sysfs attribute is
+			always in 0-255 range (1 = 9V, 255 = 12V). Setting the
+			attribute to 0 turns off the fan completely.
+pwm[1-3]_enable		1 if the fan can be controlled by writing to the
+			corresponding pwm* attribute, 0 otherwise. The device
+			can control only the fans it detected itself, so the
+			attribute is read-only.
+pwm[1-3]_mode		Read-only, 1 for PWM-controlled fans, 0 for other fans
+			(or if no fan connected).
+update_interval		The interval at which all inputs are updated (in
+			milliseconds). The default is 1000ms. Minimum is 250ms.
+=======================	========================================================
diff --git a/MAINTAINERS b/MAINTAINERS
index f26920f0fa65..8b2342317dc6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13543,6 +13543,13 @@ S:	Maintained
 F:	Documentation/hwmon/nzxt-kraken2.rst
 F:	drivers/hwmon/nzxt-kraken2.c
 
+NZXT-SMART2 HARDWARE MONITORING DRIVER
+M:	Aleksandr Mezin <mezin.alexander@gmail.com>
+L:	linux-hwmon@vger.kernel.org
+S:	Maintained
+F:	Documentation/hwmon/nzxt-smart2.rst
+F:	drivers/hwmon/nzxt-smart2.c
+
 OBJAGG
 M:	Jiri Pirko <jiri@nvidia.com>
 L:	netdev@vger.kernel.org
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index c4578e8f34bb..5301b7fcfa49 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1502,6 +1502,16 @@ config SENSORS_NZXT_KRAKEN2
 	  This driver can also be built as a module. If so, the module
 	  will be called nzxt-kraken2.
 
+config SENSORS_NZXT_SMART2
+	tristate "NZXT RGB & Fan Controller/Smart Device v2"
+	depends on USB_HID
+	help
+	  If you say yes here you get support for hardware monitoring for the
+	  NZXT RGB & Fan Controller/Smart Device v2.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called nzxt-smart2.
+
 source "drivers/hwmon/occ/Kconfig"
 
 config SENSORS_PCF8591
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 162940270661..335a3b45c862 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -156,6 +156,7 @@ obj-$(CONFIG_SENSORS_NPCM7XX)	+= npcm750-pwm-fan.o
 obj-$(CONFIG_SENSORS_NSA320)	+= nsa320-hwmon.o
 obj-$(CONFIG_SENSORS_NTC_THERMISTOR)	+= ntc_thermistor.o
 obj-$(CONFIG_SENSORS_NZXT_KRAKEN2) += nzxt-kraken2.o
+obj-$(CONFIG_SENSORS_NZXT_SMART2) += nzxt-smart2.o
 obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o
 obj-$(CONFIG_SENSORS_PC87427)	+= pc87427.o
 obj-$(CONFIG_SENSORS_PCF8591)	+= pcf8591.o
diff --git a/drivers/hwmon/nzxt-smart2.c b/drivers/hwmon/nzxt-smart2.c
new file mode 100644
index 000000000000..534d39b8908e
--- /dev/null
+++ b/drivers/hwmon/nzxt-smart2.c
@@ -0,0 +1,829 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Reverse-engineered NZXT RGB & Fan Controller/Smart Device v2 driver.
+ *
+ * Copyright (c) 2021 Aleksandr Mezin
+ */
+
+#include <linux/hid.h>
+#include <linux/hwmon.h>
+#include <linux/math.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/wait.h>
+
+#include <asm/byteorder.h>
+#include <asm/unaligned.h>
+
+/*
+ * The device has only 3 fan channels/connectors. But all HID reports have
+ * space reserved for up to 8 channels.
+ */
+#define FAN_CHANNELS 3
+#define FAN_CHANNELS_MAX 8
+
+#define UPDATE_INTERVAL_DEFAULT_MS 1000
+
+/* These strings match labels on the device exactly */
+static const char *const fan_label[] = {
+	"FAN 1",
+	"FAN 2",
+	"FAN 3",
+};
+
+static const char *const curr_label[] = {
+	"FAN 1 Current",
+	"FAN 2 Current",
+	"FAN 3 Current",
+};
+
+static const char *const in_label[] = {
+	"FAN 1 Voltage",
+	"FAN 2 Voltage",
+	"FAN 3 Voltage",
+};
+
+enum {
+	INPUT_REPORT_ID_FAN_CONFIG = 0x61,
+	INPUT_REPORT_ID_FAN_STATUS = 0x67,
+};
+
+enum {
+	FAN_STATUS_REPORT_SPEED = 0x02,
+	FAN_STATUS_REPORT_VOLTAGE = 0x04,
+};
+
+enum {
+	FAN_TYPE_NONE = 0,
+	FAN_TYPE_DC = 1,
+	FAN_TYPE_PWM = 2,
+};
+
+struct unknown_static_data {
+	/*
+	 * Some configuration data? Stays the same after fan speed changes,
+	 * changes in fan configuration, reboots and driver reloads.
+	 *
+	 * The same data in multiple report types.
+	 *
+	 * Byte 12 seems to be the number of fan channels, but I am not sure.
+	 */
+	u8 unknown1[14];
+} __packed;
+
+/*
+ * The device sends this input report in response to "detect fans" command:
+ * a 2-byte output report { 0x60, 0x03 }.
+ */
+struct fan_config_report {
+	/* report_id should be INPUT_REPORT_ID_FAN_CONFIG = 0x61 */
+	u8 report_id;
+	/* Always 0x03 */
+	u8 magic;
+	struct unknown_static_data unknown_data;
+	/* Fan type as detected by the device. See FAN_TYPE_* enum. */
+	u8 fan_type[FAN_CHANNELS_MAX];
+} __packed;
+
+/*
+ * The device sends these reports at a fixed interval (update interval) -
+ * one report with type = FAN_STATUS_REPORT_SPEED, and one report with type =
+ * FAN_STATUS_REPORT_VOLTAGE per update interval.
+ */
+struct fan_status_report {
+	/* report_id should be INPUT_REPORT_ID_STATUS = 0x67 */
+	u8 report_id;
+	/* FAN_STATUS_REPORT_SPEED = 0x02 or FAN_STATUS_REPORT_VOLTAGE = 0x04 */
+	u8 type;
+	struct unknown_static_data unknown_data;
+	/* Fan type as detected by the device. See FAN_TYPE_* enum. */
+	u8 fan_type[FAN_CHANNELS_MAX];
+
+	union {
+		/* When type == FAN_STATUS_REPORT_SPEED */
+		struct {
+			/*
+			 * Fan speed, in RPM. Zero for channels without fans
+			 * connected.
+			 */
+			__le16 fan_rpm[FAN_CHANNELS_MAX];
+			/*
+			 * Fan duty cycle, in percent. Non-zero even for
+			 * channels without fans connected.
+			 */
+			u8 duty_percent[FAN_CHANNELS_MAX];
+			/*
+			 * Exactly the same values as duty_percent[], non-zero
+			 * for disconnected fans too.
+			 */
+			u8 duty_percent_dup[FAN_CHANNELS_MAX];
+			/* "Case Noise" in db */
+			u8 noise_db;
+		} __packed fan_speed;
+		/* When type == FAN_STATUS_REPORT_VOLTAGE */
+		struct {
+			/*
+			 * Voltage, in millivolts. Non-zero even when fan is
+			 * not connected.
+			 */
+			__le16 fan_in[FAN_CHANNELS_MAX];
+			/*
+			 * Current, in milliamperes. Near-zero when
+			 * disconnected.
+			 */
+			__le16 fan_current[FAN_CHANNELS_MAX];
+		} __packed fan_voltage;
+	} __packed;
+} __packed;
+
+#define OUTPUT_REPORT_SIZE 64
+
+enum {
+	OUTPUT_REPORT_ID_INIT_COMMAND = 0x60,
+	OUTPUT_REPORT_ID_SET_FAN_SPEED = 0x62,
+};
+
+enum {
+	INIT_COMMAND_SET_UPDATE_INTERVAL = 0x02,
+	INIT_COMMAND_DETECT_FANS = 0x03,
+};
+
+/*
+ * This output report sets pwm duty cycle/target fan speed for one or more
+ * channels.
+ */
+struct set_fan_speed_report {
+	/* report_id should be OUTPUT_REPORT_ID_SET_FAN_SPEED = 0x62 */
+	u8 report_id;
+	/* Should be 0x01 */
+	u8 magic;
+	/* To change fan speed on i-th channel, set i-th bit here */
+	u8 channel_bit_mask;
+	/*
+	 * Fan duty cycle/target speed in percent. For voltage-controlled fans,
+	 * the minimal voltage (duty_percent = 1) is about 9V.
+	 * Setting duty_percent to 0 (if the channel is selected in
+	 * channel_bit_mask) turns off the fan completely (regardless of the
+	 * control mode).
+	 */
+	u8 duty_percent[FAN_CHANNELS_MAX];
+} __packed;
+
+struct drvdata {
+	struct hid_device *hid;
+	struct device *hwmon;
+
+	u8 fan_duty_percent[FAN_CHANNELS];
+	u16 fan_rpm[FAN_CHANNELS];
+	bool pwm_status_received;
+
+	u16 fan_in[FAN_CHANNELS];
+	u16 fan_curr[FAN_CHANNELS];
+	bool voltage_status_received;
+
+	u8 fan_type[FAN_CHANNELS];
+	bool fan_config_received;
+
+	/*
+	 * wq is used to wait for *_received flags to become true.
+	 * All accesses to *_received flags and fan_* arrays are performed with
+	 * wq.lock held.
+	 */
+	wait_queue_head_t wq;
+	/*
+	 * mutex is used to:
+	 * 1) Prevent concurrent conflicting changes to update interval and pwm
+	 * values (after sending an output hid report, the corresponding field
+	 * in drvdata must be updated, and only then new output reports can be
+	 * sent).
+	 * 2) Synchronize access to output_buffer (well, the buffer is here,
+	 * because synchronization is necessary anyway - so why not get rid of
+	 * a kmalloc?).
+	 */
+	struct mutex mutex;
+	long update_interval;
+	u8 output_buffer[OUTPUT_REPORT_SIZE];
+};
+
+static long scale_pwm_value(long val, long orig_max, long new_max)
+{
+	if (val <= 0)
+		return 0;
+
+	/*
+	 * Positive values should not become zero: 0 completely turns off the
+	 * fan.
+	 */
+	return max(1L, DIV_ROUND_CLOSEST(min(val, orig_max) * new_max, orig_max));
+}
+
+static void handle_fan_config_report(struct drvdata *drvdata, void *data, int size)
+{
+	struct fan_config_report *report = data;
+	int i;
+
+	if (size < sizeof(struct fan_config_report))
+		return;
+
+	if (report->magic != 0x03)
+		return;
+
+	spin_lock(&drvdata->wq.lock);
+
+	for (i = 0; i < FAN_CHANNELS; i++)
+		drvdata->fan_type[i] = report->fan_type[i];
+
+	drvdata->fan_config_received = true;
+	wake_up_all_locked(&drvdata->wq);
+	spin_unlock(&drvdata->wq.lock);
+}
+
+static void handle_fan_status_report(struct drvdata *drvdata, void *data, int size)
+{
+	struct fan_status_report *report = data;
+	int i;
+
+	if (size < sizeof(struct fan_status_report))
+		return;
+
+	spin_lock(&drvdata->wq.lock);
+
+	/*
+	 * The device sends INPUT_REPORT_ID_FAN_CONFIG = 0x61 report in response
+	 * to "detect fans" command. Only accept other data after getting 0x61,
+	 * to make sure that fan detection is complete. In particular, fan
+	 * detection resets pwm values.
+	 */
+	if (!drvdata->fan_config_received) {
+		spin_unlock(&drvdata->wq.lock);
+		return;
+	}
+
+	for (i = 0; i < FAN_CHANNELS; i++) {
+		if (drvdata->fan_type[i] == report->fan_type[i])
+			continue;
+
+		/*
+		 * This should not happen (if my expectations about the device
+		 * are correct).
+		 *
+		 * Even if the userspace sends fan detect command through
+		 * hidraw, fan config report should arrive first.
+		 */
+		hid_warn_once(drvdata->hid,
+			      "Fan %d type changed unexpectedly from %d to %d",
+			      i, drvdata->fan_type[i], report->fan_type[i]);
+		drvdata->fan_type[i] = report->fan_type[i];
+	}
+
+	switch (report->type) {
+	case FAN_STATUS_REPORT_SPEED:
+		for (i = 0; i < FAN_CHANNELS; i++) {
+			drvdata->fan_rpm[i] =
+				get_unaligned_le16(&report->fan_speed.fan_rpm[i]);
+			drvdata->fan_duty_percent[i] =
+				report->fan_speed.duty_percent[i];
+		}
+
+		drvdata->pwm_status_received = true;
+		wake_up_all_locked(&drvdata->wq);
+		break;
+
+	case FAN_STATUS_REPORT_VOLTAGE:
+		for (i = 0; i < FAN_CHANNELS; i++) {
+			drvdata->fan_in[i] =
+				get_unaligned_le16(&report->fan_voltage.fan_in[i]);
+			drvdata->fan_curr[i] =
+				get_unaligned_le16(&report->fan_voltage.fan_current[i]);
+		}
+
+		drvdata->voltage_status_received = true;
+		wake_up_all_locked(&drvdata->wq);
+		break;
+	}
+
+	spin_unlock(&drvdata->wq.lock);
+}
+
+static umode_t nzxt_smart2_hwmon_is_visible(const void *data,
+					    enum hwmon_sensor_types type,
+					    u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+		case hwmon_pwm_enable:
+			return 0644;
+
+		default:
+			return 0444;
+		}
+
+	case hwmon_chip:
+		switch (attr) {
+		case hwmon_chip_update_interval:
+			return 0644;
+
+		default:
+			return 0444;
+		}
+
+	default:
+		return 0444;
+	}
+}
+
+static int nzxt_smart2_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+				  u32 attr, int channel, long *val)
+{
+	struct drvdata *drvdata = dev_get_drvdata(dev);
+	int res = -EINVAL;
+
+	if (type == hwmon_chip) {
+		switch (attr) {
+		case hwmon_chip_update_interval:
+			*val = drvdata->update_interval;
+			return 0;
+
+		default:
+			return -EINVAL;
+		}
+	}
+
+	spin_lock_irq(&drvdata->wq.lock);
+
+	switch (type) {
+	case hwmon_pwm:
+		/*
+		 * fancontrol:
+		 * 1) remembers pwm* values when it starts
+		 * 2) needs pwm*_enable to be 1 on controlled fans
+		 * So make sure we have correct data before allowing pwm* reads.
+		 * Returning errors for pwm of fan speed read can even cause
+		 * fancontrol to shut down. So the wait is unavoidable.
+		 */
+		switch (attr) {
+		case hwmon_pwm_enable:
+			res = wait_event_interruptible_locked_irq(drvdata->wq,
+								  drvdata->fan_config_received);
+			if (res)
+				goto unlock;
+
+			*val = drvdata->fan_type[channel] != FAN_TYPE_NONE;
+			break;
+
+		case hwmon_pwm_mode:
+			res = wait_event_interruptible_locked_irq(drvdata->wq,
+								  drvdata->fan_config_received);
+			if (res)
+				goto unlock;
+
+			*val = drvdata->fan_type[channel] == FAN_TYPE_PWM;
+			break;
+
+		case hwmon_pwm_input:
+			res = wait_event_interruptible_locked_irq(drvdata->wq,
+								  drvdata->pwm_status_received);
+			if (res)
+				goto unlock;
+
+			*val = scale_pwm_value(drvdata->fan_duty_percent[channel],
+					       100, 255);
+			break;
+		}
+		break;
+
+	case hwmon_fan:
+		/*
+		 * It's not strictly necessary to wait for *_received in the
+		 * remaining cases (fancontrol doesn't care about them). But I'm
+		 * doing it to have consistent behavior.
+		 */
+		if (attr == hwmon_fan_input) {
+			res = wait_event_interruptible_locked_irq(drvdata->wq,
+								  drvdata->pwm_status_received);
+			if (res)
+				goto unlock;
+
+			*val = drvdata->fan_rpm[channel];
+		}
+		break;
+
+	case hwmon_in:
+		if (attr == hwmon_in_input) {
+			res = wait_event_interruptible_locked_irq(drvdata->wq,
+								  drvdata->voltage_status_received);
+			if (res)
+				goto unlock;
+
+			*val = drvdata->fan_in[channel];
+		}
+		break;
+
+	case hwmon_curr:
+		if (attr == hwmon_curr_input) {
+			res = wait_event_interruptible_locked_irq(drvdata->wq,
+								  drvdata->voltage_status_received);
+			if (res)
+				goto unlock;
+
+			*val = drvdata->fan_curr[channel];
+		}
+		break;
+
+	default:
+		break;
+	}
+
+unlock:
+	spin_unlock_irq(&drvdata->wq.lock);
+	return res;
+}
+
+static int send_output_report(struct drvdata *drvdata, const void *data,
+			      size_t data_size)
+{
+	int ret;
+
+	if (data_size > sizeof(drvdata->output_buffer))
+		return -EINVAL;
+
+	memcpy(drvdata->output_buffer, data, data_size);
+
+	if (data_size < sizeof(drvdata->output_buffer))
+		memset(drvdata->output_buffer + data_size, 0,
+		       sizeof(drvdata->output_buffer) - data_size);
+
+	ret = hid_hw_output_report(drvdata->hid, drvdata->output_buffer,
+				   sizeof(drvdata->output_buffer));
+	return ret < 0 ? ret : 0;
+}
+
+static int set_pwm(struct drvdata *drvdata, int channel, long val)
+{
+	int ret;
+	u8 duty_percent = scale_pwm_value(val, 255, 100);
+
+	struct set_fan_speed_report report = {
+		.report_id = OUTPUT_REPORT_ID_SET_FAN_SPEED,
+		.magic = 1,
+		.channel_bit_mask = 1 << channel
+	};
+
+	ret = mutex_lock_interruptible(&drvdata->mutex);
+	if (ret)
+		return ret;
+
+	report.duty_percent[channel] = duty_percent;
+	ret = send_output_report(drvdata, &report, sizeof(report));
+	if (ret)
+		goto unlock;
+
+	/*
+	 * pwmconfig and fancontrol scripts expect pwm writes to take effect
+	 * immediately (i. e. read from pwm* sysfs should return the value
+	 * written into it). The device seems to always accept pwm values - even
+	 * when there is no fan connected - so update pwm status without waiting
+	 * for a report, to make pwmconfig and fancontrol happy. Worst case -
+	 * if the device didn't accept new pwm value for some reason (never seen
+	 * this in practice) - it will be reported incorrectly only until next
+	 * update. This avoids "fan stuck" messages from pwmconfig, and
+	 * fancontrol setting fan speed to 100% during shutdown.
+	 */
+	spin_lock_bh(&drvdata->wq.lock);
+	drvdata->fan_duty_percent[channel] = duty_percent;
+	spin_unlock_bh(&drvdata->wq.lock);
+
+unlock:
+	mutex_unlock(&drvdata->mutex);
+	return ret;
+}
+
+/*
+ * Workaround for fancontrol/pwmconfig trying to write to pwm*_enable even if it
+ * already is 1 and read-only. Otherwise, fancontrol won't restore pwm on
+ * shutdown properly.
+ */
+static int set_pwm_enable(struct drvdata *drvdata, int channel, long val)
+{
+	long expected_val;
+	int res;
+
+	spin_lock_irq(&drvdata->wq.lock);
+
+	res = wait_event_interruptible_locked_irq(drvdata->wq,
+						  drvdata->fan_config_received);
+	if (res) {
+		spin_unlock_irq(&drvdata->wq.lock);
+		return res;
+	}
+
+	expected_val = drvdata->fan_type[channel] != FAN_TYPE_NONE;
+
+	spin_unlock_irq(&drvdata->wq.lock);
+
+	return (val == expected_val) ? 0 : -EOPNOTSUPP;
+}
+
+/*
+ * Control byte	| Actual update interval in seconds
+ * 0xff		| 65.5
+ * 0xf7		| 63.46
+ * 0x7f		| 32.74
+ * 0x3f		| 16.36
+ * 0x1f		| 8.17
+ * 0x0f		| 4.07
+ * 0x07		| 2.02
+ * 0x03		| 1.00
+ * 0x02		| 0.744
+ * 0x01		| 0.488
+ * 0x00		| 0.25
+ */
+static u8 update_interval_to_control_byte(long interval)
+{
+	if (interval <= 250)
+		return 0;
+
+	return clamp_val(1 + DIV_ROUND_CLOSEST(interval - 488, 256), 0, 255);
+}
+
+static long control_byte_to_update_interval(u8 control_byte)
+{
+	if (control_byte == 0)
+		return 250;
+
+	return 488 + (control_byte - 1) * 256;
+}
+
+static int set_update_interval(struct drvdata *drvdata, long val)
+{
+	u8 control = update_interval_to_control_byte(val);
+	u8 report[] = {
+		OUTPUT_REPORT_ID_INIT_COMMAND,
+		INIT_COMMAND_SET_UPDATE_INTERVAL,
+		0x01,
+		0xe8,
+		control,
+		0x01,
+		0xe8,
+		control,
+	};
+	int ret;
+
+	ret = send_output_report(drvdata, report, sizeof(report));
+	if (ret)
+		return ret;
+
+	drvdata->update_interval = control_byte_to_update_interval(control);
+	return 0;
+}
+
+static int init_device(struct drvdata *drvdata, long update_interval)
+{
+	int ret;
+	u8 detect_fans_report[] = {
+		OUTPUT_REPORT_ID_INIT_COMMAND,
+		INIT_COMMAND_DETECT_FANS,
+	};
+
+	ret = send_output_report(drvdata, detect_fans_report,
+				 sizeof(detect_fans_report));
+	if (ret)
+		return ret;
+
+	return set_update_interval(drvdata, update_interval);
+}
+
+static int nzxt_smart2_hwmon_write(struct device *dev,
+				   enum hwmon_sensor_types type, u32 attr,
+				   int channel, long val)
+{
+	struct drvdata *drvdata = dev_get_drvdata(dev);
+	int ret;
+
+	switch (type) {
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_enable:
+			return set_pwm_enable(drvdata, channel, val);
+
+		case hwmon_pwm_input:
+			return set_pwm(drvdata, channel, val);
+
+		default:
+			return -EINVAL;
+		}
+
+	case hwmon_chip:
+		switch (attr) {
+		case hwmon_chip_update_interval:
+			ret = mutex_lock_interruptible(&drvdata->mutex);
+			if (ret)
+				return ret;
+
+			ret = set_update_interval(drvdata, val);
+
+			mutex_unlock(&drvdata->mutex);
+			return ret;
+
+		default:
+			return -EINVAL;
+		}
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int nzxt_smart2_hwmon_read_string(struct device *dev,
+					 enum hwmon_sensor_types type, u32 attr,
+					 int channel, const char **str)
+{
+	switch (type) {
+	case hwmon_fan:
+		*str = fan_label[channel];
+		return 0;
+	case hwmon_curr:
+		*str = curr_label[channel];
+		return 0;
+	case hwmon_in:
+		*str = in_label[channel];
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct hwmon_ops nzxt_smart2_hwmon_ops = {
+	.is_visible = nzxt_smart2_hwmon_is_visible,
+	.read = nzxt_smart2_hwmon_read,
+	.read_string = nzxt_smart2_hwmon_read_string,
+	.write = nzxt_smart2_hwmon_write,
+};
+
+static const struct hwmon_channel_info *nzxt_smart2_channel_info[] = {
+	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_LABEL,
+			   HWMON_F_INPUT | HWMON_F_LABEL,
+			   HWMON_F_INPUT | HWMON_F_LABEL),
+	HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_MODE | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_MODE | HWMON_PWM_ENABLE,
+			   HWMON_PWM_INPUT | HWMON_PWM_MODE | HWMON_PWM_ENABLE),
+	HWMON_CHANNEL_INFO(in, HWMON_I_INPUT | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LABEL),
+	HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT | HWMON_C_LABEL,
+			   HWMON_C_INPUT | HWMON_C_LABEL,
+			   HWMON_C_INPUT | HWMON_C_LABEL),
+	HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL),
+	NULL
+};
+
+static const struct hwmon_chip_info nzxt_smart2_chip_info = {
+	.ops = &nzxt_smart2_hwmon_ops,
+	.info = nzxt_smart2_channel_info,
+};
+
+static int nzxt_smart2_hid_raw_event(struct hid_device *hdev,
+				     struct hid_report *report, u8 *data, int size)
+{
+	struct drvdata *drvdata = hid_get_drvdata(hdev);
+	u8 report_id = *data;
+
+	switch (report_id) {
+	case INPUT_REPORT_ID_FAN_CONFIG:
+		handle_fan_config_report(drvdata, data, size);
+		break;
+
+	case INPUT_REPORT_ID_FAN_STATUS:
+		handle_fan_status_report(drvdata, data, size);
+		break;
+	}
+
+	return 0;
+}
+
+static int nzxt_smart2_hid_reset_resume(struct hid_device *hdev)
+{
+	struct drvdata *drvdata = hid_get_drvdata(hdev);
+
+	/*
+	 * Userspace is still frozen (so no concurrent sysfs attribute access
+	 * is possible), but raw_event can already be called concurrently.
+	 */
+	spin_lock_bh(&drvdata->wq.lock);
+	drvdata->fan_config_received = false;
+	drvdata->pwm_status_received = false;
+	drvdata->voltage_status_received = false;
+	spin_unlock_bh(&drvdata->wq.lock);
+
+	return init_device(drvdata, drvdata->update_interval);
+}
+
+static int nzxt_smart2_hid_probe(struct hid_device *hdev,
+				 const struct hid_device_id *id)
+{
+	struct drvdata *drvdata;
+	int ret;
+
+	drvdata = devm_kzalloc(&hdev->dev, sizeof(struct drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->hid = hdev;
+	hid_set_drvdata(hdev, drvdata);
+
+	init_waitqueue_head(&drvdata->wq);
+
+	mutex_init(&drvdata->mutex);
+	devm_add_action(&hdev->dev, (void (*)(void *))mutex_destroy,
+			&drvdata->mutex);
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return ret;
+
+	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
+	if (ret)
+		return ret;
+
+	ret = hid_hw_open(hdev);
+	if (ret)
+		goto out_hw_stop;
+
+	hid_device_io_start(hdev);
+
+	init_device(drvdata, UPDATE_INTERVAL_DEFAULT_MS);
+
+	drvdata->hwmon =
+		hwmon_device_register_with_info(&hdev->dev, "nzxtsmart2", drvdata,
+						&nzxt_smart2_chip_info, NULL);
+	if (IS_ERR(drvdata->hwmon)) {
+		ret = PTR_ERR(drvdata->hwmon);
+		goto out_hw_close;
+	}
+
+	return 0;
+
+out_hw_close:
+	hid_hw_close(hdev);
+
+out_hw_stop:
+	hid_hw_stop(hdev);
+	return ret;
+}
+
+static void nzxt_smart2_hid_remove(struct hid_device *hdev)
+{
+	struct drvdata *drvdata = hid_get_drvdata(hdev);
+
+	hwmon_device_unregister(drvdata->hwmon);
+
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
+static const struct hid_device_id nzxt_smart2_hid_id_table[] = {
+	{ HID_USB_DEVICE(0x1e71, 0x2006) }, /* NZXT Smart Device V2 */
+	{ HID_USB_DEVICE(0x1e71, 0x200d) }, /* NZXT Smart Device V2 */
+	{ HID_USB_DEVICE(0x1e71, 0x2009) }, /* NZXT RGB & Fan Controller */
+	{ HID_USB_DEVICE(0x1e71, 0x200e) }, /* NZXT RGB & Fan Controller */
+	{ HID_USB_DEVICE(0x1e71, 0x2010) }, /* NZXT RGB & Fan Controller */
+	{},
+};
+
+static struct hid_driver nzxt_smart2_hid_driver = {
+	.name = "nzxt-smart2",
+	.id_table = nzxt_smart2_hid_id_table,
+	.probe = nzxt_smart2_hid_probe,
+	.remove = nzxt_smart2_hid_remove,
+	.raw_event = nzxt_smart2_hid_raw_event,
+#ifdef CONFIG_PM
+	.reset_resume = nzxt_smart2_hid_reset_resume,
+#endif
+};
+
+static int __init nzxt_smart2_init(void)
+{
+	return hid_register_driver(&nzxt_smart2_hid_driver);
+}
+
+static void __exit nzxt_smart2_exit(void)
+{
+	hid_unregister_driver(&nzxt_smart2_hid_driver);
+}
+
+MODULE_DEVICE_TABLE(hid, nzxt_smart2_hid_id_table);
+MODULE_AUTHOR("Aleksandr Mezin <mezin.alexander@gmail.com>");
+MODULE_DESCRIPTION("Driver for NZXT RGB & Fan Controller/Smart Device V2");
+MODULE_LICENSE("GPL");
+
+/*
+ * With module_init()/module_hid_driver() and the driver built into the kernel:
+ *
+ * Driver 'nzxt_smart2' was unable to register with bus_type 'hid' because the
+ * bus was not initialized.
+ */
+late_initcall(nzxt_smart2_init);
+module_exit(nzxt_smart2_exit);
