diff mbox series

[v2,2/2] hwmon: (hs3001) Add driver for Renesas HS3001

Message ID 20230716150556.26155-2-andre.werner@systec-electronic.com (mailing list archive)
State Superseded
Headers show
Series [v2,1/2] dt-bindings: hwmon: Add description for new hwmon driver hs3001 | expand

Commit Message

werneazc July 16, 2023, 3:05 p.m. UTC
Add base support for Renesas HS3001 temperature
and humidity sensors and its compatibles HS3002,
HS3003 and HS3004.

The sensor has a fix I2C address 0x44. The resolution
is fixed to 14bit (ref. Missing feature).

Missing feature:
- Accessing non-volatile memory: Custom board has no
  possibility to control voltage supply of sensor. Thus,
  we cannot send the necessary control commands within
  the first 10ms after power-on.

Signed-off-by: Andre Werner <andre.werner@systec-electronic.com>

Changelog:
v1: Initial version
v2: Redesign following recommendations of reviewers; Bugfixes
---
 Documentation/hwmon/hs3001.rst |  37 +++++
 MAINTAINERS                    |   6 +
 drivers/hwmon/Kconfig          |  10 ++
 drivers/hwmon/Makefile         |   1 +
 drivers/hwmon/hs3001.c         | 259 +++++++++++++++++++++++++++++++++
 5 files changed, 313 insertions(+)
 create mode 100644 Documentation/hwmon/hs3001.rst
 create mode 100644 drivers/hwmon/hs3001.c

Comments

Guenter Roeck July 16, 2023, 3:09 p.m. UTC | #1
On 7/16/23 08:05, Andre Werner wrote:
> Add base support for Renesas HS3001 temperature
> and humidity sensors and its compatibles HS3002,
> HS3003 and HS3004.
> 
> The sensor has a fix I2C address 0x44. The resolution
> is fixed to 14bit (ref. Missing feature).
> 
> Missing feature:
> - Accessing non-volatile memory: Custom board has no
>    possibility to control voltage supply of sensor. Thus,
>    we cannot send the necessary control commands within
>    the first 10ms after power-on.
> 
> Signed-off-by: Andre Werner <andre.werner@systec-electronic.com>
> 
> Changelog:
> v1: Initial version
> v2: Redesign following recommendations of reviewers; Bugfixes

That doesn't really mean anything. You force me to go back to v1
and check what exactly you changed, and that will take time.

Guenter

> ---
>   Documentation/hwmon/hs3001.rst |  37 +++++
>   MAINTAINERS                    |   6 +
>   drivers/hwmon/Kconfig          |  10 ++
>   drivers/hwmon/Makefile         |   1 +
>   drivers/hwmon/hs3001.c         | 259 +++++++++++++++++++++++++++++++++
>   5 files changed, 313 insertions(+)
>   create mode 100644 Documentation/hwmon/hs3001.rst
>   create mode 100644 drivers/hwmon/hs3001.c
> 
> diff --git a/Documentation/hwmon/hs3001.rst b/Documentation/hwmon/hs3001.rst
> new file mode 100644
> index 000000000000..703fb9c45313
> --- /dev/null
> +++ b/Documentation/hwmon/hs3001.rst
> @@ -0,0 +1,37 @@
> +.. SPDX-License-Identifier: GPL-2.0-or-later
> +
> +Kernel driver HS3001
> +===================
> +
> +Supported chips:
> +
> +  * Renesas HS3001, HS3002, HS3003, HS3004
> +
> +    Prefix: 'hs3001'
> +
> +    Addresses scanned: -
> +
> +    Datasheet: https://www.renesas.com/us/en/document/dst/hs300x-datasheet?r=417401
> +
> +Author:
> +
> +  - Andre Werner <andre.werner@systec-electronic.com>
> +
> +Description
> +-----------
> +
> +This driver implements support for the Renesas HS3001 chips, a humidity
> +and temperature family. Temperature is measured in degrees celsius, relative
> +humidity is expressed as a percentage. In the sysfs interface, all values are
> +scaled by 1000, i.e. the value for 31.5 degrees celsius is 31500.
> +
> +The device communicates with the I2C protocol. Sensors have the I2C
> +address 0x44 by default.
> +
> +sysfs-Interface
> +---------------
> +
> +===============================================================================
> +temp1_input:        temperature input
> +humidity1_input:    humidity input
> +===============================================================================
> diff --git a/MAINTAINERS b/MAINTAINERS
> index dfbb271f1667..4d8603436f9f 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9484,6 +9484,12 @@ S:	Maintained
>   W:	http://artax.karlin.mff.cuni.cz/~mikulas/vyplody/hpfs/index-e.cgi
>   F:	fs/hpfs/
>   
> +HS3001 Hardware Temperature and Humidity Sensor
> +M:	Andre Werner <andre.werner@systec-electronic.com>
> +L:	linux-hwmon@vger.kernel.org
> +S:	Maintained
> +F:	drivers/hwmon/hs3001.c
> +
>   HSI SUBSYSTEM
>   M:	Sebastian Reichel <sre@kernel.org>
>   S:	Maintained
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 307477b8a371..ca6be5a23271 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -734,6 +734,16 @@ config SENSORS_HIH6130
>   	  This driver can also be built as a module. If so, the module
>   	  will be called hih6130.
>   
> +config SENSORS_HS3001
> +	tristate "Renesas HS3001 humidity and temperature sensors"
> +	depends on I2C
> +	help
> +	  If you say yes here you get support for the Renesas HS3001,
> +	  to HS3004 humidity and temperature sensors.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called hs3001.
> +
>   config SENSORS_IBMAEM
>   	tristate "IBM Active Energy Manager temperature/power sensors and control"
>   	select IPMI_SI
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 3f4b0fda0998..cdae4e1fc919 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -86,6 +86,7 @@ obj-$(CONFIG_SENSORS_GSC)	+= gsc-hwmon.o
>   obj-$(CONFIG_SENSORS_GPIO_FAN)	+= gpio-fan.o
>   obj-$(CONFIG_SENSORS_GXP_FAN_CTRL) += gxp-fan-ctrl.o
>   obj-$(CONFIG_SENSORS_HIH6130)	+= hih6130.o
> +obj-$(CONFIG_SENSORS_HS3001)	+= hs3001.o
>   obj-$(CONFIG_SENSORS_ULTRA45)	+= ultra45_env.o
>   obj-$(CONFIG_SENSORS_I5500)	+= i5500_temp.o
>   obj-$(CONFIG_SENSORS_I5K_AMB)	+= i5k_amb.o
> diff --git a/drivers/hwmon/hs3001.c b/drivers/hwmon/hs3001.c
> new file mode 100644
> index 000000000000..af8ad72dccb0
> --- /dev/null
> +++ b/drivers/hwmon/hs3001.c
> @@ -0,0 +1,259 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/* This is a non-complete driver implementation for the
> + * HS3001 humidity and temperature sensor and compatibles. It does not include
> + * the configuration possibilities, where it needs to be set to 'programming mode'
> + * during power-up.
> + *
> + *
> + * Copyright (C) 2022 SYS TEC electronic AG
> + * Author: Andre Werner <andre.werner@systec-electronic.com>
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/hwmon.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +
> +/* Measurement times */
> +#define HS3001_WAKEUP_TIME		100		/* us */
> +#define HS3001_8BIT_RESOLUTION	550		/* us */
> +#define HS3001_10BIT_RESOLUTION	1310	/* us */
> +#define HS3001_12BIT_RESOLUTION	4500	/* us */
> +#define HS3001_14BIT_RESOLUTION	16900	/* us */
> +
> +#define HS3001_RESPONSE_LENGTH	4
> +
> +#define HS3001_FIXPOINT_ARITH	1000
> +#define HS3001_MIN_TEMPERATURE	(-40 * HS3001_FIXPOINT_ARITH)	/* milli degree */
> +#define HS3001_MAX_TEMPERATURE	(125 * HS3001_FIXPOINT_ARITH)	/* milli degree */
> +#define HS3001_MIN_HUMIDITY		(0 * HS3001_FIXPOINT_ARITH)	/* milli percent */
> +#define HS3001_MAX_HUMIDITY		(100 * HS3001_FIXPOINT_ARITH)	/* milli percent */
> +
> +#define HS3001_MASK_HUMIDITY_0X3FFF		0x3FFF
> +#define HS3001_MASK_TEMPERATURE_0XFFFC	0xFFFC
> +#define HS3001_MASK_STATUS_0XC0			0xC0
> +#define HS3001_STATUS_SHIFT				6
> +
> +/* Definitions for Status Bits of A/D Data */
> +#define HS3001_DATA_VALID	0x00	/* Valid Data */
> +#define HS3001_DATA_STALE	0x01	/* Stale Data */
> +
> +#define LIMIT_MAX	0
> +#define LIMIT_MIN	1
> +
> +enum hs3001_chips {
> +	hs3001,
> +};
> +
> +struct hs3001_data {
> +	struct i2c_client *client;
> +	enum hs3001_chips type;
> +	u32 wait_time;		/* in us */
> +	int temperature;	/* in milli degree */
> +	u32 humidity;		/* in milli % */
> +};
> +
> +static int hs3001_extract_temperature(u16 raw)
> +{
> +	/* fixpoint arithmetic 1 digit */
> +	int temp = ((raw & HS3001_MASK_TEMPERATURE_0XFFFC) >> 2) *
> +	    HS3001_FIXPOINT_ARITH;
> +
> +	temp /= (1 << 14) - 1;
> +
> +	return temp * 165 - 40 * HS3001_FIXPOINT_ARITH;
> +}
> +
> +static u32 hs3001_extract_humidity(u16 raw)
> +{
> +	int hum = (raw & HS3001_MASK_HUMIDITY_0X3FFF) * HS3001_FIXPOINT_ARITH;
> +
> +	hum /= (1 << 14) - 1;
> +
> +	return hum * 100;
> +}
> +
> +static int hs3001_data_fetch_command(struct i2c_client *client,
> +				     struct hs3001_data *data)
> +{
> +	int ret;
> +	u8 buf[HS3001_RESPONSE_LENGTH];
> +	u8 hs3001_status;
> +
> +	ret = i2c_master_recv(client, buf, HS3001_RESPONSE_LENGTH);
> +
> +	if (ret != HS3001_RESPONSE_LENGTH) {
> +		ret = ret < 0 ? ret : -EIO;
> +		dev_dbg(&client->dev,
> +			"Error in i2c communication. Error code: %d.\n", ret);
> +		return ret;
> +	}
> +
> +	hs3001_status = (buf[0] & HS3001_MASK_STATUS_0XC0) >>
> +	    HS3001_STATUS_SHIFT;
> +	if (hs3001_status == HS3001_DATA_STALE) {
> +		dev_dbg(&client->dev, "Sensor busy.\n");
> +		return -EBUSY;
> +	} else if (hs3001_status != HS3001_DATA_VALID) {
> +		dev_dbg(&client->dev, "Data invalid.\n");
> +		return -EIO;
> +	}
> +
> +	data->humidity =
> +	    hs3001_extract_humidity(be16_to_cpup((__be16 *)&buf[0]));
> +	data->temperature =
> +	    hs3001_extract_temperature(be16_to_cpup((__be16 *)&buf[2]));
> +
> +	return 0;
> +}
> +
> +umode_t hs3001_is_visible(const void *data, enum hwmon_sensor_types type,
> +			  u32 attr, int channel)
> +{
> +	/* Both, humidity and temperature can only be read. */
> +	return 0444;
> +}
> +
> +int hs3001_read(struct device *dev, enum hwmon_sensor_types type,
> +		u32 attr, int channel, long *val)
> +{
> +	struct hs3001_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
> +	int ret;
> +	unsigned char buf[1] = { 0x00 };
> +
> +	ret = i2c_master_send(client, buf, 0);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Sensor needs some time to process measurement depending on
> +	 * resolution
> +	 */
> +	fsleep(data->wait_time);
> +
> +	ret = hs3001_data_fetch_command(client, data);
> +	if (ret < 0)
> +		return ret;
> +
> +	switch (type) {
> +	case hwmon_temp:
> +		switch (attr) {
> +		case hwmon_temp_input:
> +			*val = data->temperature;
> +			break;
> +		default:
> +			return -EINVAL;
> +		}
> +		break;
> +	case hwmon_humidity:
> +		switch (attr) {
> +		case hwmon_humidity_input:
> +			*val = data->humidity;
> +			break;
> +		default:
> +			return -EINVAL;
> +		}
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct hwmon_channel_info *hs3001_info[] = {
> +	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
> +	HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT),
> +	NULL
> +};
> +
> +static const struct hwmon_ops hs3001_hwmon_ops = {
> +	.is_visible = hs3001_is_visible,
> +	.read = hs3001_read,
> +};
> +
> +static const struct hwmon_chip_info hs3001_chip_info = {
> +	.ops = &hs3001_hwmon_ops,
> +	.info = hs3001_info,
> +};
> +
> +/* device ID table */
> +static const struct i2c_device_id hs3001_ids[] = {
> +	{ "hs3001", hs3001 },
> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, hs3001_ids);
> +
> +static const struct of_device_id hs3001_of_match[] = {
> +	{.compatible = "renesas,hs3001",
> +	 .data = (void *)hs3001
> +	},
> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, hs3001_of_match);
> +
> +static int hs3001_probe(struct i2c_client *client)
> +{
> +	struct hs3001_data *data;
> +	struct device *hwmon_dev;
> +	struct device *dev = &client->dev;
> +	int ret;
> +
> +	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
> +		return -EOPNOTSUPP;
> +
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->client = client;
> +
> +	if (client->dev.of_node)
> +		data->type = (enum hs3001_chips)of_device_get_match_data(&client->dev);
> +	else
> +		data->type = i2c_match_id(hs3001_ids, client)->driver_data;
> +
> +	/* Measurement time = wake-up time + measurement time temperature
> +	 * + measurment time humidity. This is currently static, because
> +	 * enabling programming mode is not supported, yet.
> +	 */
> +	data->wait_time = (HS3001_WAKEUP_TIME + HS3001_14BIT_RESOLUTION +
> +			   HS3001_14BIT_RESOLUTION);
> +
> +	/* Test access to device */
> +	ret = i2c_master_send(client, NULL, 0);
> +	if (ret)
> +		return ret;
> +
> +	hwmon_dev = devm_hwmon_device_register_with_info(dev,
> +				client->name, data, &hs3001_chip_info, NULL);
> +
> +	if (IS_ERR(hwmon_dev))
> +		return dev_err_probe(dev, PTR_ERR(hwmon_dev),
> +				     "Unable to register hwmon device.\n");
> +
> +	return 0;
> +}
> +
> +static struct i2c_driver hs3001_i2c_driver = {
> +	.driver = {
> +		   .name = "hs3001",
> +		   .of_match_table = hs3001_of_match,
> +	},
> +	.probe_new = hs3001_probe,
> +	.id_table = hs3001_ids,
> +};
> +
> +module_i2c_driver(hs3001_i2c_driver);
> +
> +MODULE_AUTHOR("Andre Werner <andre.werner@systec-electronic.com>");
> +MODULE_DESCRIPTION("HS3001 humidity and temperature sensor base  driver");
> +MODULE_LICENSE("GPL");
diff mbox series

Patch

diff --git a/Documentation/hwmon/hs3001.rst b/Documentation/hwmon/hs3001.rst
new file mode 100644
index 000000000000..703fb9c45313
--- /dev/null
+++ b/Documentation/hwmon/hs3001.rst
@@ -0,0 +1,37 @@ 
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver HS3001
+===================
+
+Supported chips:
+
+  * Renesas HS3001, HS3002, HS3003, HS3004
+
+    Prefix: 'hs3001'
+
+    Addresses scanned: -
+
+    Datasheet: https://www.renesas.com/us/en/document/dst/hs300x-datasheet?r=417401
+
+Author:
+
+  - Andre Werner <andre.werner@systec-electronic.com>
+
+Description
+-----------
+
+This driver implements support for the Renesas HS3001 chips, a humidity
+and temperature family. Temperature is measured in degrees celsius, relative
+humidity is expressed as a percentage. In the sysfs interface, all values are
+scaled by 1000, i.e. the value for 31.5 degrees celsius is 31500.
+
+The device communicates with the I2C protocol. Sensors have the I2C
+address 0x44 by default.
+
+sysfs-Interface
+---------------
+
+===============================================================================
+temp1_input:        temperature input
+humidity1_input:    humidity input
+===============================================================================
diff --git a/MAINTAINERS b/MAINTAINERS
index dfbb271f1667..4d8603436f9f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9484,6 +9484,12 @@  S:	Maintained
 W:	http://artax.karlin.mff.cuni.cz/~mikulas/vyplody/hpfs/index-e.cgi
 F:	fs/hpfs/
 
+HS3001 Hardware Temperature and Humidity Sensor
+M:	Andre Werner <andre.werner@systec-electronic.com>
+L:	linux-hwmon@vger.kernel.org
+S:	Maintained
+F:	drivers/hwmon/hs3001.c
+
 HSI SUBSYSTEM
 M:	Sebastian Reichel <sre@kernel.org>
 S:	Maintained
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 307477b8a371..ca6be5a23271 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -734,6 +734,16 @@  config SENSORS_HIH6130
 	  This driver can also be built as a module. If so, the module
 	  will be called hih6130.
 
+config SENSORS_HS3001
+	tristate "Renesas HS3001 humidity and temperature sensors"
+	depends on I2C
+	help
+	  If you say yes here you get support for the Renesas HS3001,
+	  to HS3004 humidity and temperature sensors.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called hs3001.
+
 config SENSORS_IBMAEM
 	tristate "IBM Active Energy Manager temperature/power sensors and control"
 	select IPMI_SI
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 3f4b0fda0998..cdae4e1fc919 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -86,6 +86,7 @@  obj-$(CONFIG_SENSORS_GSC)	+= gsc-hwmon.o
 obj-$(CONFIG_SENSORS_GPIO_FAN)	+= gpio-fan.o
 obj-$(CONFIG_SENSORS_GXP_FAN_CTRL) += gxp-fan-ctrl.o
 obj-$(CONFIG_SENSORS_HIH6130)	+= hih6130.o
+obj-$(CONFIG_SENSORS_HS3001)	+= hs3001.o
 obj-$(CONFIG_SENSORS_ULTRA45)	+= ultra45_env.o
 obj-$(CONFIG_SENSORS_I5500)	+= i5500_temp.o
 obj-$(CONFIG_SENSORS_I5K_AMB)	+= i5k_amb.o
diff --git a/drivers/hwmon/hs3001.c b/drivers/hwmon/hs3001.c
new file mode 100644
index 000000000000..af8ad72dccb0
--- /dev/null
+++ b/drivers/hwmon/hs3001.c
@@ -0,0 +1,259 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* This is a non-complete driver implementation for the
+ * HS3001 humidity and temperature sensor and compatibles. It does not include
+ * the configuration possibilities, where it needs to be set to 'programming mode'
+ * during power-up.
+ *
+ *
+ * Copyright (C) 2022 SYS TEC electronic AG
+ * Author: Andre Werner <andre.werner@systec-electronic.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+/* Measurement times */
+#define HS3001_WAKEUP_TIME		100		/* us */
+#define HS3001_8BIT_RESOLUTION	550		/* us */
+#define HS3001_10BIT_RESOLUTION	1310	/* us */
+#define HS3001_12BIT_RESOLUTION	4500	/* us */
+#define HS3001_14BIT_RESOLUTION	16900	/* us */
+
+#define HS3001_RESPONSE_LENGTH	4
+
+#define HS3001_FIXPOINT_ARITH	1000
+#define HS3001_MIN_TEMPERATURE	(-40 * HS3001_FIXPOINT_ARITH)	/* milli degree */
+#define HS3001_MAX_TEMPERATURE	(125 * HS3001_FIXPOINT_ARITH)	/* milli degree */
+#define HS3001_MIN_HUMIDITY		(0 * HS3001_FIXPOINT_ARITH)	/* milli percent */
+#define HS3001_MAX_HUMIDITY		(100 * HS3001_FIXPOINT_ARITH)	/* milli percent */
+
+#define HS3001_MASK_HUMIDITY_0X3FFF		0x3FFF
+#define HS3001_MASK_TEMPERATURE_0XFFFC	0xFFFC
+#define HS3001_MASK_STATUS_0XC0			0xC0
+#define HS3001_STATUS_SHIFT				6
+
+/* Definitions for Status Bits of A/D Data */
+#define HS3001_DATA_VALID	0x00	/* Valid Data */
+#define HS3001_DATA_STALE	0x01	/* Stale Data */
+
+#define LIMIT_MAX	0
+#define LIMIT_MIN	1
+
+enum hs3001_chips {
+	hs3001,
+};
+
+struct hs3001_data {
+	struct i2c_client *client;
+	enum hs3001_chips type;
+	u32 wait_time;		/* in us */
+	int temperature;	/* in milli degree */
+	u32 humidity;		/* in milli % */
+};
+
+static int hs3001_extract_temperature(u16 raw)
+{
+	/* fixpoint arithmetic 1 digit */
+	int temp = ((raw & HS3001_MASK_TEMPERATURE_0XFFFC) >> 2) *
+	    HS3001_FIXPOINT_ARITH;
+
+	temp /= (1 << 14) - 1;
+
+	return temp * 165 - 40 * HS3001_FIXPOINT_ARITH;
+}
+
+static u32 hs3001_extract_humidity(u16 raw)
+{
+	int hum = (raw & HS3001_MASK_HUMIDITY_0X3FFF) * HS3001_FIXPOINT_ARITH;
+
+	hum /= (1 << 14) - 1;
+
+	return hum * 100;
+}
+
+static int hs3001_data_fetch_command(struct i2c_client *client,
+				     struct hs3001_data *data)
+{
+	int ret;
+	u8 buf[HS3001_RESPONSE_LENGTH];
+	u8 hs3001_status;
+
+	ret = i2c_master_recv(client, buf, HS3001_RESPONSE_LENGTH);
+
+	if (ret != HS3001_RESPONSE_LENGTH) {
+		ret = ret < 0 ? ret : -EIO;
+		dev_dbg(&client->dev,
+			"Error in i2c communication. Error code: %d.\n", ret);
+		return ret;
+	}
+
+	hs3001_status = (buf[0] & HS3001_MASK_STATUS_0XC0) >>
+	    HS3001_STATUS_SHIFT;
+	if (hs3001_status == HS3001_DATA_STALE) {
+		dev_dbg(&client->dev, "Sensor busy.\n");
+		return -EBUSY;
+	} else if (hs3001_status != HS3001_DATA_VALID) {
+		dev_dbg(&client->dev, "Data invalid.\n");
+		return -EIO;
+	}
+
+	data->humidity =
+	    hs3001_extract_humidity(be16_to_cpup((__be16 *)&buf[0]));
+	data->temperature =
+	    hs3001_extract_temperature(be16_to_cpup((__be16 *)&buf[2]));
+
+	return 0;
+}
+
+umode_t hs3001_is_visible(const void *data, enum hwmon_sensor_types type,
+			  u32 attr, int channel)
+{
+	/* Both, humidity and temperature can only be read. */
+	return 0444;
+}
+
+int hs3001_read(struct device *dev, enum hwmon_sensor_types type,
+		u32 attr, int channel, long *val)
+{
+	struct hs3001_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	int ret;
+	unsigned char buf[1] = { 0x00 };
+
+	ret = i2c_master_send(client, buf, 0);
+	if (ret < 0)
+		return ret;
+
+	/* Sensor needs some time to process measurement depending on
+	 * resolution
+	 */
+	fsleep(data->wait_time);
+
+	ret = hs3001_data_fetch_command(client, data);
+	if (ret < 0)
+		return ret;
+
+	switch (type) {
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+			*val = data->temperature;
+			break;
+		default:
+			return -EINVAL;
+		}
+		break;
+	case hwmon_humidity:
+		switch (attr) {
+		case hwmon_humidity_input:
+			*val = data->humidity;
+			break;
+		default:
+			return -EINVAL;
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct hwmon_channel_info *hs3001_info[] = {
+	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+	HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT),
+	NULL
+};
+
+static const struct hwmon_ops hs3001_hwmon_ops = {
+	.is_visible = hs3001_is_visible,
+	.read = hs3001_read,
+};
+
+static const struct hwmon_chip_info hs3001_chip_info = {
+	.ops = &hs3001_hwmon_ops,
+	.info = hs3001_info,
+};
+
+/* device ID table */
+static const struct i2c_device_id hs3001_ids[] = {
+	{ "hs3001", hs3001 },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(i2c, hs3001_ids);
+
+static const struct of_device_id hs3001_of_match[] = {
+	{.compatible = "renesas,hs3001",
+	 .data = (void *)hs3001
+	},
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, hs3001_of_match);
+
+static int hs3001_probe(struct i2c_client *client)
+{
+	struct hs3001_data *data;
+	struct device *hwmon_dev;
+	struct device *dev = &client->dev;
+	int ret;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return -EOPNOTSUPP;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+
+	if (client->dev.of_node)
+		data->type = (enum hs3001_chips)of_device_get_match_data(&client->dev);
+	else
+		data->type = i2c_match_id(hs3001_ids, client)->driver_data;
+
+	/* Measurement time = wake-up time + measurement time temperature
+	 * + measurment time humidity. This is currently static, because
+	 * enabling programming mode is not supported, yet.
+	 */
+	data->wait_time = (HS3001_WAKEUP_TIME + HS3001_14BIT_RESOLUTION +
+			   HS3001_14BIT_RESOLUTION);
+
+	/* Test access to device */
+	ret = i2c_master_send(client, NULL, 0);
+	if (ret)
+		return ret;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev,
+				client->name, data, &hs3001_chip_info, NULL);
+
+	if (IS_ERR(hwmon_dev))
+		return dev_err_probe(dev, PTR_ERR(hwmon_dev),
+				     "Unable to register hwmon device.\n");
+
+	return 0;
+}
+
+static struct i2c_driver hs3001_i2c_driver = {
+	.driver = {
+		   .name = "hs3001",
+		   .of_match_table = hs3001_of_match,
+	},
+	.probe_new = hs3001_probe,
+	.id_table = hs3001_ids,
+};
+
+module_i2c_driver(hs3001_i2c_driver);
+
+MODULE_AUTHOR("Andre Werner <andre.werner@systec-electronic.com>");
+MODULE_DESCRIPTION("HS3001 humidity and temperature sensor base  driver");
+MODULE_LICENSE("GPL");