diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index 1272d8107f0d..2722addde895 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -46,13 +46,18 @@
 #define ADXL345_INACT_Z_EN		BIT(0)
 #define ADXL345_INACT_Y_EN		BIT(1)
 #define ADXL345_INACT_X_EN		BIT(2)
+#define ADXL345_REG_INACT_ACDC		BIT(3)
 #define ADXL345_INACT_XYZ_EN		(ADXL345_INACT_Z_EN | ADXL345_INACT_Y_EN | ADXL345_INACT_X_EN)
 
 #define ADXL345_ACT_Z_EN		BIT(4)
 #define ADXL345_ACT_Y_EN		BIT(5)
 #define ADXL345_ACT_X_EN		BIT(6)
+#define ADXL345_REG_ACT_ACDC		BIT(7)
 #define ADXL345_ACT_XYZ_EN		(ADXL345_ACT_Z_EN | ADXL345_ACT_Y_EN | ADXL345_ACT_X_EN)
 
+#define ADXL345_COUPLING_DC		0
+#define ADXL345_COUPLING_AC		1
+
 /* single/double tap */
 enum adxl345_tap_type {
 	ADXL345_SINGLE_TAP,
@@ -80,16 +85,29 @@ static const unsigned int adxl345_tap_time_reg[] = {
 enum adxl345_activity_type {
 	ADXL345_ACTIVITY,
 	ADXL345_INACTIVITY,
+	ADXL345_ACTIVITY_AC,
+	ADXL345_INACTIVITY_AC,
 };
 
 static const unsigned int adxl345_act_int_reg[] = {
 	[ADXL345_ACTIVITY] = ADXL345_INT_ACTIVITY,
 	[ADXL345_INACTIVITY] = ADXL345_INT_INACTIVITY,
+	[ADXL345_ACTIVITY_AC] = ADXL345_INT_ACTIVITY,
+	[ADXL345_INACTIVITY_AC] = ADXL345_INT_INACTIVITY,
 };
 
 static const unsigned int adxl345_act_thresh_reg[] = {
 	[ADXL345_ACTIVITY] = ADXL345_REG_THRESH_ACT,
 	[ADXL345_INACTIVITY] = ADXL345_REG_THRESH_INACT,
+	[ADXL345_ACTIVITY_AC] = ADXL345_REG_THRESH_ACT,
+	[ADXL345_INACTIVITY_AC] = ADXL345_REG_THRESH_INACT,
+};
+
+static const unsigned int adxl345_act_acdc_msk[] = {
+	[ADXL345_ACTIVITY] = ADXL345_REG_ACT_ACDC,
+	[ADXL345_INACTIVITY] = ADXL345_REG_INACT_ACDC,
+	[ADXL345_ACTIVITY_AC] = ADXL345_REG_ACT_ACDC,
+	[ADXL345_INACTIVITY_AC] = ADXL345_REG_INACT_ACDC,
 };
 
 enum adxl345_odr {
@@ -188,6 +206,14 @@ static const struct iio_event_spec adxl345_events[] = {
 			BIT(IIO_EV_INFO_ENABLE) |
 			BIT(IIO_EV_INFO_VALUE),
 	},
+	{
+		/* activity, ac bit set */
+		.type = IIO_EV_TYPE_MAG_ADAPTIVE,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_shared_by_type =
+			BIT(IIO_EV_INFO_ENABLE) |
+			BIT(IIO_EV_INFO_VALUE),
+	},
 	{
 		/* single tap */
 		.type = IIO_EV_TYPE_GESTURE,
@@ -242,6 +268,15 @@ static const struct iio_event_spec adxl345_fake_chan_events[] = {
 			BIT(IIO_EV_INFO_VALUE) |
 			BIT(IIO_EV_INFO_PERIOD),
 	},
+	{
+		/* inactivity, AC bit set */
+		.type = IIO_EV_TYPE_MAG_ADAPTIVE,
+		.dir = IIO_EV_DIR_FALLING,
+		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
+		.mask_shared_by_type =
+			BIT(IIO_EV_INFO_VALUE) |
+			BIT(IIO_EV_INFO_PERIOD),
+	},
 };
 
 static const struct iio_chan_spec adxl345_channels[] = {
@@ -349,12 +384,114 @@ static int adxl345_set_inact_time(struct adxl345_state *st, u32 val_s)
 	return regmap_write(st->regmap, ADXL345_REG_TIME_INACT, val);
 }
 
+/**
+ * adxl345_is_act_inact_ac() - Verify if AC or DC coupling is currently enabled.
+ *
+ * @st: The device data.
+ * @type: The activity or inactivity type.
+ *
+ * Given a type of activity / inactivity combined with either AC coupling set or
+ * default to DC, this function verifies if the combination is currently
+ * configured, hence enabled or not.
+ *
+ * Return: true if configured coupling matches the provided type, else a negative
+ *         error value.
+ */
+static int adxl345_is_act_inact_ac(struct adxl345_state *st,
+				   enum adxl345_activity_type type)
+{
+	unsigned int regval;
+	bool coupling;
+	int ret;
+
+	ret = regmap_read(st->regmap, ADXL345_REG_ACT_INACT_CTRL, &regval);
+	if (ret)
+		return ret;
+
+	coupling = adxl345_act_acdc_msk[type] & regval;
+
+	switch (type) {
+	case ADXL345_ACTIVITY:
+	case ADXL345_INACTIVITY:
+		return coupling == ADXL345_COUPLING_DC;
+	case ADXL345_ACTIVITY_AC:
+	case ADXL345_INACTIVITY_AC:
+		return coupling == ADXL345_COUPLING_AC;
+	default:
+		return -EINVAL;
+	}
+}
+
+/**
+ * adxl345_set_act_inact_ac() - Configure AC coupling or DC coupling.
+ *
+ * @st: The device data.
+ * @type: Provide a type of activity or inactivity.
+ * @cmd_en: enable or disable AC coupling.
+ *
+ * Enables AC coupling or DC coupling depending on the provided type argument.
+ * Note: Activity and inactivity can be either AC coupled or DC coupled not
+ * both at the same time.
+ *
+ * Return: 0 if successful, else error value.
+ */
+static int adxl345_set_act_inact_ac(struct adxl345_state *st,
+				    enum adxl345_activity_type type,
+				    bool cmd_en)
+{
+	unsigned int act_inact_ac;
+
+	if (type == ADXL345_ACTIVITY_AC || type == ADXL345_INACTIVITY_AC)
+		act_inact_ac = ADXL345_COUPLING_AC && cmd_en;
+	else
+		act_inact_ac = ADXL345_COUPLING_DC && cmd_en;
+
+	/*
+	 * A setting of false selects dc-coupled operation, and a setting of
+	 * true enables ac-coupled operation. In dc-coupled operation, the
+	 * current acceleration magnitude is compared directly with
+	 * ADXL345_REG_THRESH_ACT and ADXL345_REG_THRESH_INACT to determine
+	 * whether activity or inactivity is detected.
+	 *
+	 * In ac-coupled operation for activity detection, the acceleration
+	 * value at the start of activity detection is taken as a reference
+	 * value. New samples of acceleration are then compared to this
+	 * reference value, and if the magnitude of the difference exceeds the
+	 * ADXL345_REG_THRESH_ACT value, the device triggers an activity
+	 * interrupt.
+	 *
+	 * Similarly, in ac-coupled operation for inactivity detection, a
+	 * reference value is used for comparison and is updated whenever the
+	 * device exceeds the inactivity threshold. After the reference value
+	 * is selected, the device compares the magnitude of the difference
+	 * between the reference value and the current acceleration with
+	 * ADXL345_REG_THRESH_INACT. If the difference is less than the value in
+	 * ADXL345_REG_THRESH_INACT for the time in ADXL345_REG_TIME_INACT, the
+	 * device is considered inactive and the inactivity interrupt is
+	 * triggered. [quoted from p. 24, ADXL345 datasheet Rev. G]
+	 *
+	 * In a conclusion, the first acceleration snapshot sample which hit the
+	 * threshold in a particular direction is always taken as acceleration
+	 * reference value to that direction. Since for the hardware activity
+	 * and inactivity depend on the x/y/z axis, so do ac and dc coupling.
+	 * Note, this sw driver always enables or disables all three x/y/z axis
+	 * for detection via act_axis_ctrl and inact_axis_ctrl, respectively.
+	 * Where in dc-coupling samples are compared against the thresholds, in
+	 * ac-coupling measurement difference to the first acceleration
+	 * reference value are compared against the threshold. So, ac-coupling
+	 * allows for a bit more dynamic compensation depending on the initial
+	 * sample.
+	 */
+	return regmap_assign_bits(st->regmap, ADXL345_REG_ACT_INACT_CTRL,
+				  adxl345_act_acdc_msk[type], act_inact_ac);
+}
+
 static int adxl345_is_act_inact_en(struct adxl345_state *st,
 				   enum adxl345_activity_type type)
 {
 	unsigned int axis_ctrl;
 	unsigned int regval;
-	bool en;
+	bool int_en, en;
 	int ret;
 
 	ret = regmap_read(st->regmap, ADXL345_REG_ACT_INACT_CTRL, &axis_ctrl);
@@ -364,11 +501,13 @@ static int adxl345_is_act_inact_en(struct adxl345_state *st,
 	/* Check if axis for activity are enabled */
 	switch (type) {
 	case ADXL345_ACTIVITY:
+	case ADXL345_ACTIVITY_AC:
 		en = FIELD_GET(ADXL345_ACT_XYZ_EN, axis_ctrl);
 		if (!en)
 			return false;
 		break;
 	case ADXL345_INACTIVITY:
+	case ADXL345_INACTIVITY_AC:
 		en = FIELD_GET(ADXL345_INACT_XYZ_EN, axis_ctrl);
 		if (!en)
 			return false;
@@ -382,23 +521,40 @@ static int adxl345_is_act_inact_en(struct adxl345_state *st,
 	if (ret)
 		return ret;
 
-	return adxl345_act_int_reg[type] & regval;
+	int_en = adxl345_act_int_reg[type] & regval;
+	if (!int_en)
+		return false;
+
+	/* Check if configured coupling matches provided type */
+	return adxl345_is_act_inact_ac(st, type);
 }
 
 static int adxl345_set_act_inact_linkbit(struct adxl345_state *st,
 					 enum adxl345_activity_type type,
 					 bool en)
 {
+	int act_ac_en, inact_ac_en;
 	int act_en, inact_en;
 
 	act_en = adxl345_is_act_inact_en(st, ADXL345_ACTIVITY);
 	if (act_en < 0)
 		return act_en;
 
+	act_ac_en = adxl345_is_act_inact_en(st, ADXL345_ACTIVITY_AC);
+	if (act_ac_en < 0)
+		return act_ac_en;
+
 	inact_en = adxl345_is_act_inact_en(st, ADXL345_INACTIVITY);
 	if (inact_en < 0)
 		return inact_en;
 
+	inact_ac_en = adxl345_is_act_inact_en(st, ADXL345_INACTIVITY_AC);
+	if (inact_ac_en < 0)
+		return inact_ac_en;
+
+	inact_en = inact_en || inact_ac_en;
+	act_en = act_en || act_ac_en;
+
 	return regmap_assign_bits(st->regmap, ADXL345_REG_POWER_CTL,
 				  ADXL345_POWER_CTL_INACT_MSK,
 				  en && act_en && inact_en);
@@ -425,7 +581,7 @@ static int adxl345_set_act_inact_en(struct adxl345_state *st,
 			return 0;
 
 		/* When turning on inactivity, check if inact time is valid */
-		if (type == ADXL345_INACTIVITY) {
+		if (type == ADXL345_INACTIVITY || type == ADXL345_INACTIVITY_AC) {
 			ret = regmap_read(st->regmap,
 					  ADXL345_REG_TIME_INACT,
 					  &period);
@@ -435,6 +591,16 @@ static int adxl345_set_act_inact_en(struct adxl345_state *st,
 			if (!period)
 				return 0;
 		}
+	} else {
+		/*
+		 * When turning off an activity, ensure that the correct
+		 * coupling event is specified. This step helps prevent misuse -
+		 * for example, if an AC-coupled activity is active and the
+		 * current call attempts to turn off a DC-coupled activity, this
+		 * inconsistency should be detected here.
+		 */
+		if (adxl345_is_act_inact_ac(st, type) <= 0)
+			return 0;
 	}
 
 	/* Start modifying configuration registers */
@@ -445,9 +611,11 @@ static int adxl345_set_act_inact_en(struct adxl345_state *st,
 	/* Enable axis according to the command */
 	switch (type) {
 	case ADXL345_ACTIVITY:
+	case ADXL345_ACTIVITY_AC:
 		axis_ctrl = ADXL345_ACT_XYZ_EN;
 		break;
 	case ADXL345_INACTIVITY:
+	case ADXL345_INACTIVITY_AC:
 		axis_ctrl = ADXL345_INACT_XYZ_EN;
 		break;
 	default:
@@ -459,6 +627,11 @@ static int adxl345_set_act_inact_en(struct adxl345_state *st,
 	if (ret)
 		return ret;
 
+	/* Update AC/DC-coupling according to the command */
+	ret = adxl345_set_act_inact_ac(st, type, cmd_en);
+	if (ret)
+		return ret;
+
 	/* Enable the interrupt line, according to the command */
 	ret = regmap_assign_bits(st->regmap, ADXL345_REG_INT_ENABLE,
 				 adxl345_act_int_reg[type], cmd_en);
@@ -951,6 +1124,10 @@ static int adxl345_read_event_config(struct iio_dev *indio_dev,
 		return adxl345_read_mag_config(st, dir,
 					       ADXL345_ACTIVITY,
 					       ADXL345_INACTIVITY);
+	case IIO_EV_TYPE_MAG_ADAPTIVE:
+		return adxl345_read_mag_config(st, dir,
+					       ADXL345_ACTIVITY_AC,
+					       ADXL345_INACTIVITY_AC);
 	case IIO_EV_TYPE_GESTURE:
 		switch (dir) {
 		case IIO_EV_DIR_SINGLETAP:
@@ -987,6 +1164,11 @@ static int adxl345_write_event_config(struct iio_dev *indio_dev,
 						ADXL345_ACTIVITY,
 						ADXL345_INACTIVITY,
 						state);
+	case IIO_EV_TYPE_MAG_ADAPTIVE:
+		return adxl345_write_mag_config(st, dir,
+						ADXL345_ACTIVITY_AC,
+						ADXL345_INACTIVITY_AC,
+						state);
 	case IIO_EV_TYPE_GESTURE:
 		switch (dir) {
 		case IIO_EV_DIR_SINGLETAP:
@@ -1096,6 +1278,11 @@ static int adxl345_read_event_value(struct iio_dev *indio_dev,
 					      ADXL345_ACTIVITY,
 					      ADXL345_INACTIVITY,
 					      val, val2);
+	case IIO_EV_TYPE_MAG_ADAPTIVE:
+		return adxl345_read_mag_value(st, dir, info,
+					      ADXL345_ACTIVITY_AC,
+					      ADXL345_INACTIVITY_AC,
+					      val, val2);
 	case IIO_EV_TYPE_GESTURE:
 		switch (info) {
 		case IIO_EV_INFO_VALUE:
@@ -1154,6 +1341,14 @@ static int adxl345_write_event_value(struct iio_dev *indio_dev,
 		if (ret)
 			return ret;
 		break;
+	case IIO_EV_TYPE_MAG_ADAPTIVE:
+		ret = adxl345_write_mag_value(st, dir, info,
+					      ADXL345_ACTIVITY_AC,
+					      ADXL345_INACTIVITY_AC,
+					      val, val2);
+		if (ret)
+			return ret;
+		break;
 	case IIO_EV_TYPE_GESTURE:
 		switch (info) {
 		case IIO_EV_INFO_VALUE:
@@ -1398,6 +1593,7 @@ static int adxl345_push_event(struct iio_dev *indio_dev, int int_stat,
 {
 	s64 ts = iio_get_time_ns(indio_dev);
 	struct adxl345_state *st = iio_priv(indio_dev);
+	unsigned int regval;
 	int samples;
 	int ret = -ENOENT;
 
@@ -1422,22 +1618,52 @@ static int adxl345_push_event(struct iio_dev *indio_dev, int int_stat,
 	}
 
 	if (FIELD_GET(ADXL345_INT_ACTIVITY, int_stat)) {
-		ret = iio_push_event(indio_dev,
-				     IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, act_dir,
-							IIO_EV_TYPE_MAG,
-							IIO_EV_DIR_RISING),
-				     ts);
+		ret = regmap_read(st->regmap, ADXL345_REG_ACT_INACT_CTRL, &regval);
+		if (ret)
+			return ret;
+
+		if (FIELD_GET(ADXL345_REG_ACT_ACDC, regval)) {
+			/* AC coupled */
+			ret = iio_push_event(indio_dev,
+					     IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, act_dir,
+								IIO_EV_TYPE_MAG_ADAPTIVE,
+								IIO_EV_DIR_RISING),
+					     ts);
+
+		} else {
+			/* DC coupled, relying on THRESH */
+			ret = iio_push_event(indio_dev,
+					     IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, act_dir,
+								IIO_EV_TYPE_MAG,
+								IIO_EV_DIR_RISING),
+					     ts);
+		}
 		if (ret)
 			return ret;
 	}
 
 	if (FIELD_GET(ADXL345_INT_INACTIVITY, int_stat)) {
-		ret = iio_push_event(indio_dev,
-				     IIO_MOD_EVENT_CODE(IIO_ACCEL, 0,
-							IIO_MOD_X_AND_Y_AND_Z,
-							IIO_EV_TYPE_MAG,
-							IIO_EV_DIR_FALLING),
-				     ts);
+		ret = regmap_read(st->regmap, ADXL345_REG_ACT_INACT_CTRL, &regval);
+		if (ret)
+			return ret;
+
+		if (FIELD_GET(ADXL345_REG_INACT_ACDC, regval)) {
+			/* AC coupled */
+			ret = iio_push_event(indio_dev,
+					     IIO_MOD_EVENT_CODE(IIO_ACCEL, 0,
+								IIO_MOD_X_AND_Y_AND_Z,
+								IIO_EV_TYPE_MAG_ADAPTIVE,
+								IIO_EV_DIR_FALLING),
+					     ts);
+		} else {
+			/* DC coupled, relying on THRESH */
+			ret = iio_push_event(indio_dev,
+					     IIO_MOD_EVENT_CODE(IIO_ACCEL, 0,
+								IIO_MOD_X_AND_Y_AND_Z,
+								IIO_EV_TYPE_MAG,
+								IIO_EV_DIR_FALLING),
+					     ts);
+		}
 		if (ret)
 			return ret;
 	}