[PATCH v2 1/2] dt-bindings: hwmon: Add description for new hwmon driver hs3001

[PATCH v2 1/2] dt-bindings: hwmon: Add description for new hwmon driver hs3001

[Andre Werner]

This is the initial description.

Signed-off-by: Andre Werner <andre.werner@systec-electronic.com>
---
 Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/trivial-devices.yaml b/Documentation/devicetree/bindings/trivial-devices.yaml
index ba2bfb547909..5a5de3f6cd37 100644
--- a/Documentation/devicetree/bindings/trivial-devices.yaml
+++ b/Documentation/devicetree/bindings/trivial-devices.yaml
@@ -320,6 +320,8 @@ properties:
             # Rohm DH2228FV
           - rohm,dh2228fv
             # S524AD0XF1 (128K/256K-bit Serial EEPROM for Low Power)
+          - renesas,hs3001
+            # Renesas HS300[1,2,3,4] Temperature and Relative Humidity Sensors
           - samsung,24ad0xd1
             # Samsung Exynos SoC SATA PHY I2C device
           - samsung,exynos-sataphy-i2c
-- 
2.41.0

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

[Andre Werner]

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>
---
 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");
-- 
2.41.0

Re: [PATCH v2 1/2] dt-bindings: hwmon: Add description for new hwmon driver hs3001

[Rob Herring]

On Fri, 14 Jul 2023 08:43:35 +0200, Andre Werner wrote:
> This is the initial description.
> 
> Signed-off-by: Andre Werner <andre.werner@systec-electronic.com>
> ---
>  Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 

Acked-by: Rob Herring <robh@kernel.org>

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

[Guenter Roeck]

On 7/13/23 23:43, 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>

Change log goes here.

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");

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

[Andre Werner]

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

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");
-- 
2.41.0

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

[Guenter Roeck]

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");

Re: [PATCH v2 1/2] dt-bindings: hwmon: Add description for new hwmon driver hs3001

[Krzysztof Kozlowski]

On 14/07/2023 08:43, Andre Werner wrote:
> This is the initial description.
> 
> Signed-off-by: Andre Werner <andre.werner@systec-electronic.com>
> ---

Please use scripts/get_maintainers.pl to get a list of necessary people
and lists to CC (and consider --no-git-fallback argument). It might
happen, that command when run on an older kernel, gives you outdated
entries. Therefore please be sure you base your patches on recent Linux
kernel.

Didn't you get this comment already? If so, why you decided to ignore it?

>  Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/trivial-devices.yaml b/Documentation/devicetree/bindings/trivial-devices.yaml
> index ba2bfb547909..5a5de3f6cd37 100644
> --- a/Documentation/devicetree/bindings/trivial-devices.yaml
> +++ b/Documentation/devicetree/bindings/trivial-devices.yaml
> @@ -320,6 +320,8 @@ properties:
>              # Rohm DH2228FV
>            - rohm,dh2228fv
>              # S524AD0XF1 (128K/256K-bit Serial EEPROM for Low Power)
> +          - renesas,hs3001
> +            # Renesas HS300[1,2,3,4] Temperature and Relative Humidity Sensors

Wrong placement of comment.

Best regards,
Krzysztof

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

[Andre Werner]

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: Extensive refactoring following recommendations of reviewers:
 - Delete unused defines and device properties. These are added in
   the initial version because the device supports a programming mode,
   but I was not able to implement it, because the custom board was
   not able to control the power supply of the device and so I cannot
   enter the programming mode of the device.
 - Correct missunderstanding comments for defines.
 - Delete mutexes for data and I2C bus accesses.
 - Replace attributes with recommented chip-info structure. In the
   initial version I followed the sth3x.c implementation that uses
   files and attributes in sysfs. The show functions are replaced by
   is_visible and read callbacks from the HWMON ABI. I also  delete pointless
   function argument checks.
 - Correct Yoda programming.
 - Refactor probe function and delete sleep and measurement of humidity
   and temperature in probe function. I kept an initial I2C
   communication to ensure that the device is accessible during probe.
 - Reduce the number of atteributes to humidity and temperature input.
---
 Documentation/hwmon/hs3001.rst |  37 +++++
 MAINTAINERS                    |   6 +
 drivers/hwmon/Kconfig          |  10 ++
 drivers/hwmon/Makefile         |   1 +
 drivers/hwmon/hs3001.c         | 261 +++++++++++++++++++++++++++++++++
 5 files changed, 315 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 aee340630eca..25d5282b43aa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9494,6 +9494,12 @@ 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..5fe42fd3831f
--- /dev/null
+++ b/drivers/hwmon/hs3001.c
@@ -0,0 +1,261 @@
+// 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) 2023 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;
+
+	ret = i2c_master_send(client, NULL, 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");
-- 
2.41.0

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

[Krzysztof Kozlowski]

On 18/07/2023 09:01, 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: Extensive refactoring following recommendations of reviewers:
>  - Delete unused defines and device properties. These are added in
>    the initial version because the device supports a programming mode,
>    but I was not able to implement it, because the custom board was
>    not able to control the power supply of the device and so I cannot
>    enter the programming mode of the device.
>  - Correct missunderstanding comments for defines.
>  - Delete mutexes for data and I2C bus accesses.
>  - Replace attributes with recommented chip-info structure. In the
>    initial version I followed the sth3x.c implementation that uses
>    files and attributes in sysfs. The show functions are replaced by
>    is_visible and read callbacks from the HWMON ABI. I also  delete pointless
>    function argument checks.
>  - Correct Yoda programming.
>  - Refactor probe function and delete sleep and measurement of humidity
>    and temperature in probe function. I kept an initial I2C
>    communication to ensure that the device is accessible during probe.
>  - Reduce the number of atteributes to humidity and temperature input.

Also wrong placement of SoB and changelog.

> ---
>  Documentation/hwmon/hs3001.rst |  37 +++++
>  MAINTAINERS                    |   6 +
>  drivers/hwmon/Kconfig          |  10 ++
>  drivers/hwmon/Makefile         |   1 +
>  drivers/hwmon/hs3001.c         | 261 +++++++++++++++++++++++++++++++++
>  5 files changed, 315 insertions(+)
>  create mode 100644 Documentation/hwmon/hs3001.rst
>  create mode 100644 drivers/hwmon/hs3001.c

...

> +/* 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,

Drop, not effectively used.

> +};

...

> +
> +/* device ID table */
> +static const struct i2c_device_id hs3001_ids[] = {
> +	{ "hs3001", hs3001 },

Drop match data

> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, hs3001_ids);
> +
> +static const struct of_device_id hs3001_of_match[] = {
> +	{.compatible = "renesas,hs3001",
> +	 .data = (void *)hs3001

Drop

> +	},
> +	{ },
> +};
> +
> +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;

This is useless and dead code. You have only one type of device. Don't
over-complicate simple things.



Best regards,
Krzysztof