These changes are the raw update to linux-4.4.6-rt14. Kernel sources

are taken from kernel.org, and rt patch from the rt wiki download page.

During the rebasing, the following patch collided:

Force tick interrupt and get rid of softirq magic(I70131fb85).

Collisions have been removed because its logic was found on the
source already.

Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

7 files changed, 643 insertions, 37 deletions

diff --git a/kernel/drivers/iio/humidity/Kconfig b/kernel/drivers/iio/humidity/Kconfig
index 4813b793b..6a23698d3 100644
--- a/kernel/drivers/iio/humidity/Kconfig
+++ b/kernel/drivers/iio/humidity/Kconfig
@@ -5,13 +5,36 @@ menu "Humidity sensors"
 
 config DHT11
 	tristate "DHT11 (and compatible sensors) driver"
-	depends on GPIOLIB
+	depends on GPIOLIB || COMPILE_TEST
 	help
 	  This driver supports reading data via a single interrupt
 	  generating GPIO line. Currently tested are DHT11 and DHT22.
 	  Other sensors should work as well as long as they speak the
 	  same protocol.
 
+config HDC100X
+	tristate "TI HDC100x relative humidity and temperature sensor"
+	depends on I2C
+	help
+	 Say yes here to build support for the TI HDC100x series of
+	 relative humidity and temperature sensors.
+
+	 To compile this driver as a module, choose M here: the module
+	 will be called hdc100x.
+
+config HTU21
+	tristate "Measurement Specialties HTU21 humidity & temperature sensor"
+	depends on I2C
+        select IIO_MS_SENSORS_I2C
+	help
+	  If you say yes here you get support for the Measurement Specialties
+	  HTU21 humidity and temperature sensor.
+	  This driver is also used for MS8607 temperature, pressure & humidity
+	  sensor
+
+	  This driver can also be built as a module. If so, the module will
+	  be called htu21.
+
 config SI7005
 	tristate "SI7005 relative humidity and temperature sensor"
 	depends on I2C
diff --git a/kernel/drivers/iio/humidity/Makefile b/kernel/drivers/iio/humidity/Makefile
index 86e2d26e9..c9f089a9a 100644
--- a/kernel/drivers/iio/humidity/Makefile
+++ b/kernel/drivers/iio/humidity/Makefile
@@ -3,5 +3,7 @@
 #
 
 obj-$(CONFIG_DHT11) += dht11.o
+obj-$(CONFIG_HDC100X) += hdc100x.o
+obj-$(CONFIG_HTU21) += htu21.o
 obj-$(CONFIG_SI7005) += si7005.o
 obj-$(CONFIG_SI7020) += si7020.o
diff --git a/kernel/drivers/iio/humidity/dht11.c b/kernel/drivers/iio/humidity/dht11.c
index 7d79a1ac5..1165b1c4f 100644
--- a/kernel/drivers/iio/humidity/dht11.c
+++ b/kernel/drivers/iio/humidity/dht11.c
@@ -33,6 +33,7 @@
 #include <linux/delay.h>
 #include <linux/gpio.h>
 #include <linux/of_gpio.h>
+#include <linux/timekeeping.h>
 
 #include <linux/iio/iio.h>
 
@@ -46,7 +47,8 @@
  * Note that when reading the sensor actually 84 edges are detected, but
  * since the last edge is not significant, we only store 83:
  */
-#define DHT11_EDGES_PER_READ (2*DHT11_BITS_PER_READ + DHT11_EDGES_PREAMBLE + 1)
+#define DHT11_EDGES_PER_READ (2 * DHT11_BITS_PER_READ + \
+			      DHT11_EDGES_PREAMBLE + 1)
 
 /* Data transmission timing (nano seconds) */
 #define DHT11_START_TRANSMISSION	18  /* ms */
@@ -62,6 +64,7 @@ struct dht11 {
 	int				irq;
 
 	struct completion		completion;
+	/* The iio sysfs interface doesn't prevent concurrent reads: */
 	struct mutex			lock;
 
 	s64				timestamp;
@@ -87,32 +90,20 @@ static unsigned char dht11_decode_byte(int *timing, int threshold)
 	return ret;
 }
 
-static int dht11_decode(struct dht11 *dht11, int offset)
+static int dht11_decode(struct dht11 *dht11, int offset, int timeres)
 {
-	int i, t, timing[DHT11_BITS_PER_READ], threshold,
-		timeres = DHT11_SENSOR_RESPONSE;
+	int i, t, timing[DHT11_BITS_PER_READ], threshold;
 	unsigned char temp_int, temp_dec, hum_int, hum_dec, checksum;
 
-	/* Calculate timestamp resolution */
-	for (i = 1; i < dht11->num_edges; ++i) {
-		t = dht11->edges[i].ts - dht11->edges[i-1].ts;
-		if (t > 0 && t < timeres)
-			timeres = t;
-	}
-	if (2*timeres > DHT11_DATA_BIT_HIGH) {
-		pr_err("dht11: timeresolution %d too bad for decoding\n",
-			timeres);
-		return -EIO;
-	}
 	threshold = DHT11_DATA_BIT_HIGH / timeres;
-	if (DHT11_DATA_BIT_LOW/timeres + 1 >= threshold)
+	if (DHT11_DATA_BIT_LOW / timeres + 1 >= threshold)
 		pr_err("dht11: WARNING: decoding ambiguous\n");
 
 	/* scale down with timeres and check validity */
 	for (i = 0; i < DHT11_BITS_PER_READ; ++i) {
-		t = dht11->edges[offset + 2*i + 2].ts -
-			dht11->edges[offset + 2*i + 1].ts;
-		if (!dht11->edges[offset + 2*i + 1].value)
+		t = dht11->edges[offset + 2 * i + 2].ts -
+			dht11->edges[offset + 2 * i + 1].ts;
+		if (!dht11->edges[offset + 2 * i + 1].value)
 			return -EIO;  /* lost synchronisation */
 		timing[i] = t / timeres;
 	}
@@ -126,7 +117,7 @@ static int dht11_decode(struct dht11 *dht11, int offset)
 	if (((hum_int + hum_dec + temp_int + temp_dec) & 0xff) != checksum)
 		return -EIO;
 
-	dht11->timestamp = iio_get_time_ns();
+	dht11->timestamp = ktime_get_real_ns();
 	if (hum_int < 20) {  /* DHT22 */
 		dht11->temperature = (((temp_int & 0x7f) << 8) + temp_dec) *
 					((temp_int & 0x80) ? -100 : 100);
@@ -154,7 +145,7 @@ static irqreturn_t dht11_handle_irq(int irq, void *data)
 
 	/* TODO: Consider making the handler safe for IRQ sharing */
 	if (dht11->num_edges < DHT11_EDGES_PER_READ && dht11->num_edges >= 0) {
-		dht11->edges[dht11->num_edges].ts = iio_get_time_ns();
+		dht11->edges[dht11->num_edges].ts = ktime_get_real_ns();
 		dht11->edges[dht11->num_edges++].value =
 						gpio_get_value(dht11->gpio);
 
@@ -166,14 +157,26 @@ static irqreturn_t dht11_handle_irq(int irq, void *data)
 }
 
 static int dht11_read_raw(struct iio_dev *iio_dev,
-			const struct iio_chan_spec *chan,
+			  const struct iio_chan_spec *chan,
 			int *val, int *val2, long m)
 {
 	struct dht11 *dht11 = iio_priv(iio_dev);
-	int ret;
+	int ret, timeres;
 
 	mutex_lock(&dht11->lock);
-	if (dht11->timestamp + DHT11_DATA_VALID_TIME < iio_get_time_ns()) {
+	if (dht11->timestamp + DHT11_DATA_VALID_TIME < ktime_get_real_ns()) {
+		timeres = ktime_get_resolution_ns();
+		if (DHT11_DATA_BIT_HIGH < 2 * timeres) {
+			dev_err(dht11->dev, "timeresolution %dns too low\n",
+				timeres);
+			/* In theory a better clock could become available
+			 * at some point ... and there is no error code
+			 * that really fits better.
+			 */
+			ret = -EAGAIN;
+			goto err;
+		}
+
 		reinit_completion(&dht11->completion);
 
 		dht11->num_edges = 0;
@@ -192,13 +195,13 @@ static int dht11_read_raw(struct iio_dev *iio_dev,
 			goto err;
 
 		ret = wait_for_completion_killable_timeout(&dht11->completion,
-								 HZ);
+							   HZ);
 
 		free_irq(dht11->irq, iio_dev);
 
 		if (ret == 0 && dht11->num_edges < DHT11_EDGES_PER_READ - 1) {
 			dev_err(&iio_dev->dev,
-					"Only %d signal edges detected\n",
+				"Only %d signal edges detected\n",
 					dht11->num_edges);
 			ret = -ETIMEDOUT;
 		}
@@ -206,9 +209,10 @@ static int dht11_read_raw(struct iio_dev *iio_dev,
 			goto err;
 
 		ret = dht11_decode(dht11,
-				dht11->num_edges == DHT11_EDGES_PER_READ ?
+				   dht11->num_edges == DHT11_EDGES_PER_READ ?
 					DHT11_EDGES_PREAMBLE :
-					DHT11_EDGES_PREAMBLE - 2);
+					DHT11_EDGES_PREAMBLE - 2,
+				timeres);
 		if (ret)
 			goto err;
 	}
@@ -261,9 +265,10 @@ static int dht11_probe(struct platform_device *pdev)
 	dht11 = iio_priv(iio);
 	dht11->dev = dev;
 
-	dht11->gpio = ret = of_get_gpio(node, 0);
+	ret = of_get_gpio(node, 0);
 	if (ret < 0)
 		return ret;
+	dht11->gpio = ret;
 	ret = devm_gpio_request_one(dev, dht11->gpio, GPIOF_IN, pdev->name);
 	if (ret)
 		return ret;
@@ -274,7 +279,7 @@ static int dht11_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	dht11->timestamp = iio_get_time_ns() - DHT11_DATA_VALID_TIME - 1;
+	dht11->timestamp = ktime_get_real_ns() - DHT11_DATA_VALID_TIME - 1;
 	dht11->num_edges = -1;
 
 	platform_set_drvdata(pdev, iio);
diff --git a/kernel/drivers/iio/humidity/hdc100x.c b/kernel/drivers/iio/humidity/hdc100x.c
new file mode 100644
index 000000000..a7f61e881
--- /dev/null
+++ b/kernel/drivers/iio/humidity/hdc100x.c
@@ -0,0 +1,320 @@
+/*
+ * hdc100x.c - Support for the TI HDC100x temperature + humidity sensors
+ *
+ * Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define HDC100X_REG_TEMP			0x00
+#define HDC100X_REG_HUMIDITY			0x01
+
+#define HDC100X_REG_CONFIG			0x02
+#define HDC100X_REG_CONFIG_HEATER_EN		BIT(13)
+
+struct hdc100x_data {
+	struct i2c_client *client;
+	struct mutex lock;
+	u16 config;
+
+	/* integration time of the sensor */
+	int adc_int_us[2];
+};
+
+/* integration time in us */
+static const int hdc100x_int_time[][3] = {
+	{ 6350, 3650, 0 },	/* IIO_TEMP channel*/
+	{ 6500, 3850, 2500 },	/* IIO_HUMIDITYRELATIVE channel */
+};
+
+/* HDC100X_REG_CONFIG shift and mask values */
+static const struct {
+	int shift;
+	int mask;
+} hdc100x_resolution_shift[2] = {
+	{ /* IIO_TEMP channel */
+		.shift = 10,
+		.mask = 1
+	},
+	{ /* IIO_HUMIDITYRELATIVE channel */
+		.shift = 8,
+		.mask = 2,
+	},
+};
+
+static IIO_CONST_ATTR(temp_integration_time_available,
+		"0.00365 0.00635");
+
+static IIO_CONST_ATTR(humidityrelative_integration_time_available,
+		"0.0025 0.00385 0.0065");
+
+static IIO_CONST_ATTR(out_current_heater_raw_available,
+		"0 1");
+
+static struct attribute *hdc100x_attributes[] = {
+	&iio_const_attr_temp_integration_time_available.dev_attr.attr,
+	&iio_const_attr_humidityrelative_integration_time_available.dev_attr.attr,
+	&iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
+	NULL
+};
+
+static struct attribute_group hdc100x_attribute_group = {
+	.attrs = hdc100x_attributes,
+};
+
+static const struct iio_chan_spec hdc100x_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.address = HDC100X_REG_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+			BIT(IIO_CHAN_INFO_SCALE) |
+			BIT(IIO_CHAN_INFO_INT_TIME) |
+			BIT(IIO_CHAN_INFO_OFFSET),
+	},
+	{
+		.type = IIO_HUMIDITYRELATIVE,
+		.address = HDC100X_REG_HUMIDITY,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+			BIT(IIO_CHAN_INFO_SCALE) |
+			BIT(IIO_CHAN_INFO_INT_TIME)
+	},
+	{
+		.type = IIO_CURRENT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.extend_name = "heater",
+		.output = 1,
+	},
+};
+
+static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
+{
+	int tmp = (~mask & data->config) | val;
+	int ret;
+
+	ret = i2c_smbus_write_word_swapped(data->client,
+						HDC100X_REG_CONFIG, tmp);
+	if (!ret)
+		data->config = tmp;
+
+	return ret;
+}
+
+static int hdc100x_set_it_time(struct hdc100x_data *data, int chan, int val2)
+{
+	int shift = hdc100x_resolution_shift[chan].shift;
+	int ret = -EINVAL;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(hdc100x_int_time[chan]); i++) {
+		if (val2 && val2 == hdc100x_int_time[chan][i]) {
+			ret = hdc100x_update_config(data,
+				hdc100x_resolution_shift[chan].mask << shift,
+				i << shift);
+			if (!ret)
+				data->adc_int_us[chan] = val2;
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static int hdc100x_get_measurement(struct hdc100x_data *data,
+				   struct iio_chan_spec const *chan)
+{
+	struct i2c_client *client = data->client;
+	int delay = data->adc_int_us[chan->address];
+	int ret;
+	int val;
+
+	/* start measurement */
+	ret = i2c_smbus_write_byte(client, chan->address);
+	if (ret < 0) {
+		dev_err(&client->dev, "cannot start measurement");
+		return ret;
+	}
+
+	/* wait for integration time to pass */
+	usleep_range(delay, delay + 1000);
+
+	/*
+	 * i2c_smbus_read_word_data cannot() be used here due to the command
+	 * value not being understood and causes NAKs preventing any reading
+	 * from being accessed.
+	 */
+	ret = i2c_smbus_read_byte(client);
+	if (ret < 0) {
+		dev_err(&client->dev, "cannot read high byte measurement");
+		return ret;
+	}
+	val = ret << 6;
+
+	ret = i2c_smbus_read_byte(client);
+	if (ret < 0) {
+		dev_err(&client->dev, "cannot read low byte measurement");
+		return ret;
+	}
+	val |= ret >> 2;
+
+	return val;
+}
+
+static int hdc100x_get_heater_status(struct hdc100x_data *data)
+{
+	return !!(data->config & HDC100X_REG_CONFIG_HEATER_EN);
+}
+
+static int hdc100x_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, int *val,
+			    int *val2, long mask)
+{
+	struct hdc100x_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW: {
+		int ret;
+
+		mutex_lock(&data->lock);
+		if (chan->type == IIO_CURRENT) {
+			*val = hdc100x_get_heater_status(data);
+			ret = IIO_VAL_INT;
+		} else {
+			ret = hdc100x_get_measurement(data, chan);
+			if (ret >= 0) {
+				*val = ret;
+				ret = IIO_VAL_INT;
+			}
+		}
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+	case IIO_CHAN_INFO_INT_TIME:
+		*val = 0;
+		*val2 = data->adc_int_us[chan->address];
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_SCALE:
+		if (chan->type == IIO_TEMP) {
+			*val = 165;
+			*val2 = 65536 >> 2;
+			return IIO_VAL_FRACTIONAL;
+		} else {
+			*val = 0;
+			*val2 = 10000;
+			return IIO_VAL_INT_PLUS_MICRO;
+		}
+		break;
+	case IIO_CHAN_INFO_OFFSET:
+		*val = -3971;
+		*val2 = 879096;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int hdc100x_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val, int val2, long mask)
+{
+	struct hdc100x_data *data = iio_priv(indio_dev);
+	int ret = -EINVAL;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_INT_TIME:
+		if (val != 0)
+			return -EINVAL;
+
+		mutex_lock(&data->lock);
+		ret = hdc100x_set_it_time(data, chan->address, val2);
+		mutex_unlock(&data->lock);
+		return ret;
+	case IIO_CHAN_INFO_RAW:
+		if (chan->type != IIO_CURRENT || val2 != 0)
+			return -EINVAL;
+
+		mutex_lock(&data->lock);
+		ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_HEATER_EN,
+					val ? HDC100X_REG_CONFIG_HEATER_EN : 0);
+		mutex_unlock(&data->lock);
+		return ret;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info hdc100x_info = {
+	.read_raw = hdc100x_read_raw,
+	.write_raw = hdc100x_write_raw,
+	.attrs = &hdc100x_attribute_group,
+	.driver_module = THIS_MODULE,
+};
+
+static int hdc100x_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct iio_dev *indio_dev;
+	struct hdc100x_data *data;
+
+	if (!i2c_check_functionality(client->adapter,
+				I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
+		return -ENODEV;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+	mutex_init(&data->lock);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->name = dev_name(&client->dev);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &hdc100x_info;
+
+	indio_dev->channels = hdc100x_channels;
+	indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
+
+	/* be sure we are in a known state */
+	hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
+	hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id hdc100x_id[] = {
+	{ "hdc100x", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, hdc100x_id);
+
+static struct i2c_driver hdc100x_driver = {
+	.driver = {
+		.name	= "hdc100x",
+	},
+	.probe = hdc100x_probe,
+	.id_table = hdc100x_id,
+};
+module_i2c_driver(hdc100x_driver);
+
+MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
+MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
+MODULE_LICENSE("GPL");
diff --git a/kernel/drivers/iio/humidity/htu21.c b/kernel/drivers/iio/humidity/htu21.c
new file mode 100644
index 000000000..d1636a749
--- /dev/null
+++ b/kernel/drivers/iio/humidity/htu21.c
@@ -0,0 +1,253 @@
+/*
+ * htu21.c - Support for Measurement-Specialties
+ *           htu21 temperature & humidity sensor
+ *	     and humidity part of MS8607 sensor
+ *
+ * Copyright (c) 2014 Measurement-Specialties
+ *
+ * Licensed under the GPL-2.
+ *
+ * (7-bit I2C slave address 0x40)
+ *
+ * Datasheet:
+ *  http://www.meas-spec.com/downloads/HTU21D.pdf
+ * Datasheet:
+ *  http://www.meas-spec.com/downloads/MS8607-02BA01.pdf
+ */
+
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/stat.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#include "../common/ms_sensors/ms_sensors_i2c.h"
+
+#define HTU21_RESET				0xFE
+
+enum {
+	HTU21,
+	MS8607
+};
+
+static const int htu21_samp_freq[4] = { 20, 40, 70, 120 };
+/* String copy of the above const for readability purpose */
+static const char htu21_show_samp_freq[] = "20 40 70 120";
+
+static int htu21_read_raw(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *channel, int *val,
+			  int *val2, long mask)
+{
+	int ret, temperature;
+	unsigned int humidity;
+	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+		switch (channel->type) {
+		case IIO_TEMP:	/* in milli °C */
+			ret = ms_sensors_ht_read_temperature(dev_data,
+							     &temperature);
+			if (ret)
+				return ret;
+			*val = temperature;
+
+			return IIO_VAL_INT;
+		case IIO_HUMIDITYRELATIVE:	/* in milli %RH */
+			ret = ms_sensors_ht_read_humidity(dev_data,
+							  &humidity);
+			if (ret)
+				return ret;
+			*val = humidity;
+
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = htu21_samp_freq[dev_data->res_index];
+
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int htu21_write_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int val, int val2, long mask)
+{
+	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
+	int i, ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		i = ARRAY_SIZE(htu21_samp_freq);
+		while (i-- > 0)
+			if (val == htu21_samp_freq[i])
+				break;
+		if (i < 0)
+			return -EINVAL;
+		mutex_lock(&dev_data->lock);
+		dev_data->res_index = i;
+		ret = ms_sensors_write_resolution(dev_data, i);
+		mutex_unlock(&dev_data->lock);
+
+		return ret;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_chan_spec htu21_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+	 },
+	{
+		.type = IIO_HUMIDITYRELATIVE,
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+	 }
+};
+
+/*
+ * Meas Spec recommendation is to not read temperature
+ * on this driver part for MS8607
+ */
+static const struct iio_chan_spec ms8607_channels[] = {
+	{
+		.type = IIO_HUMIDITYRELATIVE,
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+	 }
+};
+
+static ssize_t htu21_show_battery_low(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
+
+	return ms_sensors_show_battery_low(dev_data, buf);
+}
+
+static ssize_t htu21_show_heater(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
+
+	return ms_sensors_show_heater(dev_data, buf);
+}
+
+static ssize_t htu21_write_heater(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
+
+	return ms_sensors_write_heater(dev_data, buf, len);
+}
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(htu21_show_samp_freq);
+static IIO_DEVICE_ATTR(battery_low, S_IRUGO,
+		       htu21_show_battery_low, NULL, 0);
+static IIO_DEVICE_ATTR(heater_enable, S_IRUGO | S_IWUSR,
+		       htu21_show_heater, htu21_write_heater, 0);
+
+static struct attribute *htu21_attributes[] = {
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	&iio_dev_attr_battery_low.dev_attr.attr,
+	&iio_dev_attr_heater_enable.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group htu21_attribute_group = {
+	.attrs = htu21_attributes,
+};
+
+static const struct iio_info htu21_info = {
+	.read_raw = htu21_read_raw,
+	.write_raw = htu21_write_raw,
+	.attrs = &htu21_attribute_group,
+	.driver_module = THIS_MODULE,
+};
+
+static int htu21_probe(struct i2c_client *client,
+		       const struct i2c_device_id *id)
+{
+	struct ms_ht_dev *dev_data;
+	struct iio_dev *indio_dev;
+	int ret;
+	u64 serial_number;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
+				     I2C_FUNC_SMBUS_WRITE_BYTE |
+				     I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
+		dev_err(&client->dev,
+			"Adapter does not support some i2c transaction\n");
+		return -ENODEV;
+	}
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	dev_data = iio_priv(indio_dev);
+	dev_data->client = client;
+	dev_data->res_index = 0;
+	mutex_init(&dev_data->lock);
+
+	indio_dev->info = &htu21_info;
+	indio_dev->name = id->name;
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	if (id->driver_data == MS8607) {
+		indio_dev->channels = ms8607_channels;
+		indio_dev->num_channels = ARRAY_SIZE(ms8607_channels);
+	} else {
+		indio_dev->channels = htu21_channels;
+		indio_dev->num_channels = ARRAY_SIZE(htu21_channels);
+	}
+
+	i2c_set_clientdata(client, indio_dev);
+
+	ret = ms_sensors_reset(client, HTU21_RESET, 15000);
+	if (ret)
+		return ret;
+
+	ret = ms_sensors_read_serial(client, &serial_number);
+	if (ret)
+		return ret;
+	dev_info(&client->dev, "Serial number : %llx", serial_number);
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id htu21_id[] = {
+	{"htu21", HTU21},
+	{"ms8607-humidity", MS8607},
+	{}
+};
+
+static struct i2c_driver htu21_driver = {
+	.probe = htu21_probe,
+	.id_table = htu21_id,
+	.driver = {
+		   .name = "htu21",
+		   },
+};
+
+module_i2c_driver(htu21_driver);
+
+MODULE_DESCRIPTION("Measurement-Specialties htu21 temperature and humidity driver");
+MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
+MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/kernel/drivers/iio/humidity/si7005.c b/kernel/drivers/iio/humidity/si7005.c
index bdd586e6d..91972ccd8 100644
--- a/kernel/drivers/iio/humidity/si7005.c
+++ b/kernel/drivers/iio/humidity/si7005.c
@@ -177,7 +177,6 @@ MODULE_DEVICE_TABLE(i2c, si7005_id);
 static struct i2c_driver si7005_driver = {
 	.driver = {
 		.name	= "si7005",
-		.owner	= THIS_MODULE,
 	},
 	.probe = si7005_probe,
 	.id_table = si7005_id,
diff --git a/kernel/drivers/iio/humidity/si7020.c b/kernel/drivers/iio/humidity/si7020.c
index fa3b809af..71991b5c0 100644
--- a/kernel/drivers/iio/humidity/si7020.c
+++ b/kernel/drivers/iio/humidity/si7020.c
@@ -50,15 +50,19 @@ static int si7020_read_raw(struct iio_dev *indio_dev,
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
-		ret = i2c_smbus_read_word_data(*client,
-					       chan->type == IIO_TEMP ?
-					       SI7020CMD_TEMP_HOLD :
-					       SI7020CMD_RH_HOLD);
+		ret = i2c_smbus_read_word_swapped(*client,
+						  chan->type == IIO_TEMP ?
+						  SI7020CMD_TEMP_HOLD :
+						  SI7020CMD_RH_HOLD);
 		if (ret < 0)
 			return ret;
 		*val = ret >> 2;
+		/*
+		 * Humidity values can slightly exceed the 0-100%RH
+		 * range and should be corrected by software
+		 */
 		if (chan->type == IIO_HUMIDITYRELATIVE)
-			*val &= GENMASK(11, 0);
+			*val = clamp_val(*val, 786, 13893);
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		if (chan->type == IIO_TEMP)