Merge tag 'iio-fixes-for-6.10b' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jic23/iio into char-misc-linus

Jonathan writes:

IIO: 2nd set of fixes for 6.10

The usual mixed bag of new stuff and long term issues that have surfaced
as a particular driver gets more adoption.

adi,ad7266
- Add missing error check that could lead to bad data being reported.
adi,ad9739a
- Fix Kconfig to not allow COMPILE_TEST to override lack SPI support.
bosch,bme680
- Fix units for pressure value (off by factor of 10)
- Fix sign on a calibration variable read back from the device
- Avoid integer overflow in compensation functions.
- Fix an issue with read sequence that leads to stale data and bad first
reading.
freescale,fxls8962af
- Kconfig dependency fixes.
ti,hdc3020
- Fix representation of hysteresis to match ABI by being an offset from
the current event threshold, not an absolute value.
xilinx,ams
- Don't include the ams_ctrl_channels in a computed mask. This driver is
making an unusual use of scan_mask (it doesn't support buffers) and that
lead to an overflow.

* tag 'iio-fixes-for-6.10b' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jic23/iio:
iio: chemical: bme680: Fix sensor data read operation
iio: chemical: bme680: Fix overflows in compensate() functions
iio: chemical: bme680: Fix calibration data variable
iio: chemical: bme680: Fix pressure value output
iio: humidity: hdc3020: fix hysteresis representation
iio: dac: fix ad9739a random config compile error
iio: accel: fxls8962af: select IIO_BUFFER & IIO_KFIFO_BUF
iio: adc: ad7266: Fix variable checking bug
iio: xilinx-ams: Don't include ams_ctrl_channels in scan_mask

drivers/iio/accel/Kconfig

···
 config FXLS8962AF
 	tristate
 	depends on I2C || !I2C # cannot be built-in for modular I2C
+	select IIO_BUFFER
+	select IIO_KFIFO_BUF
 
 config FXLS8962AF_I2C
 	tristate "NXP FXLS8962AF/FXLS8964AF Accelerometer I2C Driver"

drivers/iio/adc/ad7266.c

···
 		ret = ad7266_read_single(st, val, chan->address);
 		iio_device_release_direct_mode(indio_dev);
 
+		if (ret < 0)
+			return ret;
 		*val = (*val >> 2) & 0xfff;
 		if (chan->scan_type.sign == 's')
 			*val = sign_extend32(*val,

drivers/iio/adc/xilinx-ams.c

···
 
 	/* Run calibration of PS & PL as part of the sequence */
 	scan_mask = BIT(0) | BIT(AMS_PS_SEQ_MAX);
-	for (i = 0; i < indio_dev->num_channels; i++)
-		scan_mask |= BIT_ULL(indio_dev->channels[i].scan_index);
+	for (i = 0; i < indio_dev->num_channels; i++) {
+		const struct iio_chan_spec *chan = &indio_dev->channels[i];
+
+		if (chan->scan_index < AMS_CTRL_SEQ_BASE)
+			scan_mask |= BIT_ULL(chan->scan_index);
+	}
 
 	if (ams->ps_base) {
 		/* put sysmon in a soft reset to change the sequence */

drivers/iio/chemical/bme680.h

···
 #define   BME680_NB_CONV_MASK			GENMASK(3, 0)
 
 #define BME680_REG_MEAS_STAT_0			0x1D
+#define   BME680_NEW_DATA_BIT			BIT(7)
 #define   BME680_GAS_MEAS_BIT			BIT(6)
+#define   BME680_MEAS_BIT			BIT(5)
 
 /* Calibration Parameters */
 #define BME680_T2_LSB_REG	0x8A

drivers/iio/chemical/bme680_core.c

···
  */
 #include <linux/acpi.h>
 #include <linux/bitfield.h>
+#include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/log2.h>
···
 	s8  par_h3;
 	s8  par_h4;
 	s8  par_h5;
-	s8  par_h6;
+	u8  par_h6;
 	s8  par_h7;
 	s8  par_gh1;
 	s16 par_gh2;
···
 	if (!calib->par_t2)
 		bme680_read_calib(data, calib);
 
-	var1 = (adc_temp >> 3) - (calib->par_t1 << 1);
+	var1 = (adc_temp >> 3) - ((s32)calib->par_t1 << 1);
 	var2 = (var1 * calib->par_t2) >> 11;
 	var3 = ((var1 >> 1) * (var1 >> 1)) >> 12;
-	var3 = (var3 * (calib->par_t3 << 4)) >> 14;
+	var3 = (var3 * ((s32)calib->par_t3 << 4)) >> 14;
 	data->t_fine = var2 + var3;
 	calc_temp = (data->t_fine * 5 + 128) >> 8;
 
···
 	var1 = (data->t_fine >> 1) - 64000;
 	var2 = ((((var1 >> 2) * (var1 >> 2)) >> 11) * calib->par_p6) >> 2;
 	var2 = var2 + (var1 * calib->par_p5 << 1);
-	var2 = (var2 >> 2) + (calib->par_p4 << 16);
+	var2 = (var2 >> 2) + ((s32)calib->par_p4 << 16);
 	var1 = (((((var1 >> 2) * (var1 >> 2)) >> 13) *
-			(calib->par_p3 << 5)) >> 3) +
+			((s32)calib->par_p3 << 5)) >> 3) +
 			((calib->par_p2 * var1) >> 1);
 	var1 = var1 >> 18;
 	var1 = ((32768 + var1) * calib->par_p1) >> 15;
···
 	var3 = ((press_comp >> 8) * (press_comp >> 8) *
 			(press_comp >> 8) * calib->par_p10) >> 17;
 
-	press_comp += (var1 + var2 + var3 + (calib->par_p7 << 7)) >> 4;
+	press_comp += (var1 + var2 + var3 + ((s32)calib->par_p7 << 7)) >> 4;
 
 	return press_comp;
 }
···
 		 (((temp_scaled * ((temp_scaled * calib->par_h5) / 100))
 		   >> 6) / 100) + (1 << 14))) >> 10;
 	var3 = var1 * var2;
-	var4 = calib->par_h6 << 7;
+	var4 = (s32)calib->par_h6 << 7;
 	var4 = (var4 + ((temp_scaled * calib->par_h7) / 100)) >> 4;
 	var5 = ((var3 >> 14) * (var3 >> 14)) >> 10;
 	var6 = (var4 * var5) >> 1;
···
 	return ilog2(val) + 1;
 }
 
+/*
+ * Taken from Bosch BME680 API:
+ * https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x.c#L490
+ */
+static int bme680_wait_for_eoc(struct bme680_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	unsigned int check;
+	int ret;
+	/*
+	 * (Sum of oversampling ratios * time per oversampling) +
+	 * TPH measurement + gas measurement + wait transition from forced mode
+	 * + heater duration
+	 */
+	int wait_eoc_us = ((data->oversampling_temp + data->oversampling_press +
+			   data->oversampling_humid) * 1936) + (477 * 4) +
+			   (477 * 5) + 1000 + (data->heater_dur * 1000);
+
+	usleep_range(wait_eoc_us, wait_eoc_us + 100);
+
+	ret = regmap_read(data->regmap, BME680_REG_MEAS_STAT_0, &check);
+	if (ret) {
+		dev_err(dev, "failed to read measurement status register.\n");
+		return ret;
+	}
+	if (check & BME680_MEAS_BIT) {
+		dev_err(dev, "Device measurement cycle incomplete.\n");
+		return -EBUSY;
+	}
+	if (!(check & BME680_NEW_DATA_BIT)) {
+		dev_err(dev, "No new data available from the device.\n");
+		return -ENODATA;
+	}
+
+	return 0;
+}
+
 static int bme680_chip_config(struct bme680_data *data)
 {
 	struct device *dev = regmap_get_device(data->regmap);
···
 	if (ret < 0)
 		return ret;
 
+	ret = bme680_wait_for_eoc(data);
+	if (ret)
+		return ret;
+
 	ret = regmap_bulk_read(data->regmap, BME680_REG_TEMP_MSB,
 			       &tmp, 3);
 	if (ret < 0) {
···
 	}
 
 	*val = bme680_compensate_press(data, adc_press);
-	*val2 = 100;
+	*val2 = 1000;
 	return IIO_VAL_FRACTIONAL;
 }
 
···
 	/* set forced mode to trigger measurement */
 	ret = bme680_set_mode(data, true);
 	if (ret < 0)
+		return ret;
+
+	ret = bme680_wait_for_eoc(data);
+	if (ret)
 		return ret;
 
 	ret = regmap_read(data->regmap, BME680_REG_MEAS_STAT_0, &check);

drivers/iio/dac/Kconfig

···
 
 config AD9739A
 	tristate "Analog Devices AD9739A RF DAC spi driver"
-	depends on SPI || COMPILE_TEST
+	depends on SPI
 	select REGMAP_SPI
 	select IIO_BACKEND
 	help

drivers/iio/humidity/hdc3020.c

···
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
+#include <linux/math64.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/pm.h>
···
 
 #define HDC3020_CRC8_POLYNOMIAL		0x31
 
-#define HDC3020_MIN_TEMP		-40
-#define HDC3020_MAX_TEMP		125
+#define HDC3020_MIN_TEMP_MICRO		-39872968
+#define HDC3020_MAX_TEMP_MICRO		124875639
+#define HDC3020_MAX_TEMP_HYST_MICRO	164748607
+#define HDC3020_MAX_HUM_MICRO		99220264
 
 struct hdc3020_data {
 	struct i2c_client *client;
···
 	return -EINVAL;
 }
 
+static int hdc3020_thresh_get_temp(u16 thresh)
+{
+	int temp;
+
+	/*
+	 * Get the temperature threshold from 9 LSBs, shift them to get
+	 * the truncated temperature threshold representation and
+	 * calculate the threshold according to the formula in the
+	 * datasheet. Result is degree celsius scaled by 65535.
+	 */
+	temp = FIELD_GET(HDC3020_THRESH_TEMP_MASK, thresh) <<
+	       HDC3020_THRESH_TEMP_TRUNC_SHIFT;
+
+	return -2949075 + (175 * temp);
+}
+
+static int hdc3020_thresh_get_hum(u16 thresh)
+{
+	int hum;
+
+	/*
+	 * Get the humidity threshold from 7 MSBs, shift them to get the
+	 * truncated humidity threshold representation and calculate the
+	 * threshold according to the formula in the datasheet. Result is
+	 * percent scaled by 65535.
+	 */
+	hum = FIELD_GET(HDC3020_THRESH_HUM_MASK, thresh) <<
+	      HDC3020_THRESH_HUM_TRUNC_SHIFT;
+
+	return hum * 100;
+}
+
+static u16 hdc3020_thresh_set_temp(int s_temp, u16 curr_thresh)
+{
+	u64 temp;
+	u16 thresh;
+
+	/*
+	 * Calculate temperature threshold, shift it down to get the
+	 * truncated threshold representation in the 9LSBs while keeping
+	 * the current humidity threshold in the 7 MSBs.
+	 */
+	temp = (u64)(s_temp + 45000000) * 65535ULL;
+	temp = div_u64(temp, 1000000 * 175) >> HDC3020_THRESH_TEMP_TRUNC_SHIFT;
+	thresh = FIELD_PREP(HDC3020_THRESH_TEMP_MASK, temp);
+	thresh |= (FIELD_GET(HDC3020_THRESH_HUM_MASK, curr_thresh) <<
+		  HDC3020_THRESH_HUM_TRUNC_SHIFT);
+
+	return thresh;
+}
+
+static u16 hdc3020_thresh_set_hum(int s_hum, u16 curr_thresh)
+{
+	u64 hum;
+	u16 thresh;
+
+	/*
+	 * Calculate humidity threshold, shift it down and up to get the
+	 * truncated threshold representation in the 7MSBs while keeping
+	 * the current temperature threshold in the 9 LSBs.
+	 */
+	hum = (u64)(s_hum) * 65535ULL;
+	hum = div_u64(hum, 1000000 * 100) >> HDC3020_THRESH_HUM_TRUNC_SHIFT;
+	thresh = FIELD_PREP(HDC3020_THRESH_HUM_MASK, hum);
+	thresh |= FIELD_GET(HDC3020_THRESH_TEMP_MASK, curr_thresh);
+
+	return thresh;
+}
+
+static
+int hdc3020_thresh_clr(s64 s_thresh, s64 s_hyst, enum iio_event_direction dir)
+{
+	s64 s_clr;
+
+	/*
+	 * Include directions when calculation the clear value,
+	 * since hysteresis is unsigned by definition and the
+	 * clear value is an absolute value which is signed.
+	 */
+	if (dir == IIO_EV_DIR_RISING)
+		s_clr = s_thresh - s_hyst;
+	else
+		s_clr = s_thresh + s_hyst;
+
+	/* Divide by 65535 to get units of micro */
+	return div_s64(s_clr, 65535);
+}
+
+static int _hdc3020_write_thresh(struct hdc3020_data *data, u16 reg, u16 val)
+{
+	u8 buf[5];
+
+	put_unaligned_be16(reg, buf);
+	put_unaligned_be16(val, buf + 2);
+	buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);
+
+	return hdc3020_write_bytes(data, buf, 5);
+}
+
 static int hdc3020_write_thresh(struct iio_dev *indio_dev,
 				const struct iio_chan_spec *chan,
 				enum iio_event_type type,
···
 				int val, int val2)
 {
 	struct hdc3020_data *data = iio_priv(indio_dev);
-	u8 buf[5];
-	u64 tmp;
-	u16 reg;
-	int ret;
+	u16 reg, reg_val, reg_thresh_rd, reg_clr_rd, reg_thresh_wr, reg_clr_wr;
+	s64 s_thresh, s_hyst, s_clr;
+	int s_val, thresh, clr, ret;
 
-	/* Supported temperature range is from –40 to 125 degree celsius */
-	if (val < HDC3020_MIN_TEMP || val > HDC3020_MAX_TEMP)
-		return -EINVAL;
-
-	/* Select threshold register */
-	if (info == IIO_EV_INFO_VALUE) {
-		if (dir == IIO_EV_DIR_RISING)
-			reg = HDC3020_S_T_RH_THRESH_HIGH;
-		else
-			reg = HDC3020_S_T_RH_THRESH_LOW;
+	/* Select threshold registers */
+	if (dir == IIO_EV_DIR_RISING) {
+		reg_thresh_rd = HDC3020_R_T_RH_THRESH_HIGH;
+		reg_thresh_wr = HDC3020_S_T_RH_THRESH_HIGH;
+		reg_clr_rd = HDC3020_R_T_RH_THRESH_HIGH_CLR;
+		reg_clr_wr = HDC3020_S_T_RH_THRESH_HIGH_CLR;
 	} else {
-		if (dir == IIO_EV_DIR_RISING)
-			reg = HDC3020_S_T_RH_THRESH_HIGH_CLR;
-		else
-			reg = HDC3020_S_T_RH_THRESH_LOW_CLR;
+		reg_thresh_rd = HDC3020_R_T_RH_THRESH_LOW;
+		reg_thresh_wr = HDC3020_S_T_RH_THRESH_LOW;
+		reg_clr_rd = HDC3020_R_T_RH_THRESH_LOW_CLR;
+		reg_clr_wr = HDC3020_S_T_RH_THRESH_LOW_CLR;
 	}
 
 	guard(mutex)(&data->lock);
-	ret = hdc3020_read_be16(data, reg);
+	ret = hdc3020_read_be16(data, reg_thresh_rd);
 	if (ret < 0)
 		return ret;
 
+	thresh = ret;
+	ret = hdc3020_read_be16(data, reg_clr_rd);
+	if (ret < 0)
+		return ret;
+
+	clr = ret;
+	/* Scale value to include decimal part into calculations */
+	s_val = (val < 0) ? (val * 1000000 - val2) : (val * 1000000 + val2);
 	switch (chan->type) {
 	case IIO_TEMP:
-		/*
-		 * Calculate temperature threshold, shift it down to get the
-		 * truncated threshold representation in the 9LSBs while keeping
-		 * the current humidity threshold in the 7 MSBs.
-		 */
-		tmp = ((u64)(((val + 45) * MICRO) + val2)) * 65535ULL;
-		tmp = div_u64(tmp, MICRO * 175);
-		val = tmp >> HDC3020_THRESH_TEMP_TRUNC_SHIFT;
-		val = FIELD_PREP(HDC3020_THRESH_TEMP_MASK, val);
-		val |= (FIELD_GET(HDC3020_THRESH_HUM_MASK, ret) <<
-			HDC3020_THRESH_HUM_TRUNC_SHIFT);
+		switch (info) {
+		case IIO_EV_INFO_VALUE:
+			s_val = max(s_val, HDC3020_MIN_TEMP_MICRO);
+			s_val = min(s_val, HDC3020_MAX_TEMP_MICRO);
+			reg = reg_thresh_wr;
+			reg_val = hdc3020_thresh_set_temp(s_val, thresh);
+			ret = _hdc3020_write_thresh(data, reg, reg_val);
+			if (ret < 0)
+				return ret;
+
+			/* Calculate old hysteresis */
+			s_thresh = (s64)hdc3020_thresh_get_temp(thresh) * 1000000;
+			s_clr = (s64)hdc3020_thresh_get_temp(clr) * 1000000;
+			s_hyst = div_s64(abs(s_thresh - s_clr), 65535);
+			/* Set new threshold */
+			thresh = reg_val;
+			/* Set old hysteresis */
+			s_val = s_hyst;
+			fallthrough;
+		case IIO_EV_INFO_HYSTERESIS:
+			/*
+			 * Function hdc3020_thresh_get_temp returns temperature
+			 * in degree celsius scaled by 65535. Scale by 1000000
+			 * to be able to subtract scaled hysteresis value.
+			 */
+			s_thresh = (s64)hdc3020_thresh_get_temp(thresh) * 1000000;
+			/*
+			 * Units of s_val are in micro degree celsius, scale by
+			 * 65535 to get same units as s_thresh.
+			 */
+			s_val = min(abs(s_val), HDC3020_MAX_TEMP_HYST_MICRO);
+			s_hyst = (s64)s_val * 65535;
+			s_clr = hdc3020_thresh_clr(s_thresh, s_hyst, dir);
+			s_clr = max(s_clr, HDC3020_MIN_TEMP_MICRO);
+			s_clr = min(s_clr, HDC3020_MAX_TEMP_MICRO);
+			reg = reg_clr_wr;
+			reg_val = hdc3020_thresh_set_temp(s_clr, clr);
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
 		break;
 	case IIO_HUMIDITYRELATIVE:
-		/*
-		 * Calculate humidity threshold, shift it down and up to get the
-		 * truncated threshold representation in the 7MSBs while keeping
-		 * the current temperature threshold in the 9 LSBs.
-		 */
-		tmp = ((u64)((val * MICRO) + val2)) * 65535ULL;
-		tmp = div_u64(tmp, MICRO * 100);
-		val = tmp >> HDC3020_THRESH_HUM_TRUNC_SHIFT;
-		val = FIELD_PREP(HDC3020_THRESH_HUM_MASK, val);
-		val |= FIELD_GET(HDC3020_THRESH_TEMP_MASK, ret);
+		s_val = (s_val < 0) ? 0 : min(s_val, HDC3020_MAX_HUM_MICRO);
+		switch (info) {
+		case IIO_EV_INFO_VALUE:
+			reg = reg_thresh_wr;
+			reg_val = hdc3020_thresh_set_hum(s_val, thresh);
+			ret = _hdc3020_write_thresh(data, reg, reg_val);
+			if (ret < 0)
+				return ret;
+
+			/* Calculate old hysteresis */
+			s_thresh = (s64)hdc3020_thresh_get_hum(thresh) * 1000000;
+			s_clr = (s64)hdc3020_thresh_get_hum(clr) * 1000000;
+			s_hyst = div_s64(abs(s_thresh - s_clr), 65535);
+			/* Set new threshold */
+			thresh = reg_val;
+			/* Try to set old hysteresis */
+			s_val = min(abs(s_hyst), HDC3020_MAX_HUM_MICRO);
+			fallthrough;
+		case IIO_EV_INFO_HYSTERESIS:
+			/*
+			 * Function hdc3020_thresh_get_hum returns relative
+			 * humidity in percent scaled by 65535. Scale by 1000000
+			 * to be able to subtract scaled hysteresis value.
+			 */
+			s_thresh = (s64)hdc3020_thresh_get_hum(thresh) * 1000000;
+			/*
+			 * Units of s_val are in micro percent, scale by 65535
+			 * to get same units as s_thresh.
+			 */
+			s_hyst = (s64)s_val * 65535;
+			s_clr = hdc3020_thresh_clr(s_thresh, s_hyst, dir);
+			s_clr = max(s_clr, 0);
+			s_clr = min(s_clr, HDC3020_MAX_HUM_MICRO);
+			reg = reg_clr_wr;
+			reg_val = hdc3020_thresh_set_hum(s_clr, clr);
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}
 
-	put_unaligned_be16(reg, buf);
-	put_unaligned_be16(val, buf + 2);
-	buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);
-	return hdc3020_write_bytes(data, buf, 5);
+	return _hdc3020_write_thresh(data, reg, reg_val);
 }
 
 static int hdc3020_read_thresh(struct iio_dev *indio_dev,
···
 			       int *val, int *val2)
 {
 	struct hdc3020_data *data = iio_priv(indio_dev);
-	u16 reg;
-	int ret;
+	u16 reg_thresh, reg_clr;
+	int thresh, clr, ret;
 
-	/* Select threshold register */
-	if (info == IIO_EV_INFO_VALUE) {
-		if (dir == IIO_EV_DIR_RISING)
-			reg = HDC3020_R_T_RH_THRESH_HIGH;
-		else
-			reg = HDC3020_R_T_RH_THRESH_LOW;
+	/* Select threshold registers */
+	if (dir == IIO_EV_DIR_RISING) {
+		reg_thresh = HDC3020_R_T_RH_THRESH_HIGH;
+		reg_clr = HDC3020_R_T_RH_THRESH_HIGH_CLR;
 	} else {
-		if (dir == IIO_EV_DIR_RISING)
-			reg = HDC3020_R_T_RH_THRESH_HIGH_CLR;
-		else
-			reg = HDC3020_R_T_RH_THRESH_LOW_CLR;
+		reg_thresh = HDC3020_R_T_RH_THRESH_LOW;
+		reg_clr = HDC3020_R_T_RH_THRESH_LOW_CLR;
 	}
 
 	guard(mutex)(&data->lock);
-	ret = hdc3020_read_be16(data, reg);
+	ret = hdc3020_read_be16(data, reg_thresh);
 	if (ret < 0)
 		return ret;
 
 	switch (chan->type) {
 	case IIO_TEMP:
-		/*
-		 * Get the temperature threshold from 9 LSBs, shift them to get
-		 * the truncated temperature threshold representation and
-		 * calculate the threshold according to the formula in the
-		 * datasheet.
-		 */
-		*val = FIELD_GET(HDC3020_THRESH_TEMP_MASK, ret);
-		*val = *val << HDC3020_THRESH_TEMP_TRUNC_SHIFT;
-		*val = -2949075 + (175 * (*val));
+		thresh = hdc3020_thresh_get_temp(ret);
+		switch (info) {
+		case IIO_EV_INFO_VALUE:
+			*val = thresh;
+			break;
+		case IIO_EV_INFO_HYSTERESIS:
+			ret = hdc3020_read_be16(data, reg_clr);
+			if (ret < 0)
+				return ret;
+
+			clr = hdc3020_thresh_get_temp(ret);
+			*val = abs(thresh - clr);
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
 		*val2 = 65535;
 		return IIO_VAL_FRACTIONAL;
 	case IIO_HUMIDITYRELATIVE:
-		/*
-		 * Get the humidity threshold from 7 MSBs, shift them to get the
-		 * truncated humidity threshold representation and calculate the
-		 * threshold according to the formula in the datasheet.
-		 */
-		*val = FIELD_GET(HDC3020_THRESH_HUM_MASK, ret);
-		*val = (*val << HDC3020_THRESH_HUM_TRUNC_SHIFT) * 100;
+		thresh = hdc3020_thresh_get_hum(ret);
+		switch (info) {
+		case IIO_EV_INFO_VALUE:
+			*val = thresh;
+			break;
+		case IIO_EV_INFO_HYSTERESIS:
+			ret = hdc3020_read_be16(data, reg_clr);
+			if (ret < 0)
+				return ret;
+
+			clr = hdc3020_thresh_get_hum(ret);
+			*val = abs(thresh - clr);
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
 		*val2 = 65535;
 		return IIO_VAL_FRACTIONAL;
 	default: