[PATCH 3/3] hwmon: (sht3x)add new non-stardard sysfs interface

[JuenKit Yip]

add "repeatability" interface to sysfs, it could be
read or written to control the sensor.

Signed-off-by: JuenKit Yip <JuenKit_Yip@xxxxxxxxxxx>
---
 Documentation/hwmon/sht3x.rst |  7 +++++++
 drivers/hwmon/sht3x.c         | 29 +++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/Documentation/hwmon/sht3x.rst b/Documentation/hwmon/sht3x.rst
index 2c87c8f58..3dc4b9c14 100644
--- a/Documentation/hwmon/sht3x.rst
+++ b/Documentation/hwmon/sht3x.rst
@@ -83,4 +83,11 @@ heater_enable:      heater enable, heating element removes excess humidity from
 update_interval:    update interval, 0 for single shot, interval in msec
 		    for periodic measurement. If the interval is not supported
 		    by the sensor, the next faster interval is chosen
+repeatability:      write or read repeatability, the higher repeatability means
+                    the longer measurement duration, the lower noise level and
+                    the larger energy consumption:
+
+                        - 0: low repeatability
+                        - 1: medium repeatability
+                        - 2: high repeatability
 =================== ============================================================
diff --git a/drivers/hwmon/sht3x.c b/drivers/hwmon/sht3x.c
index eb968b9d3..209090a48 100644
--- a/drivers/hwmon/sht3x.c
+++ b/drivers/hwmon/sht3x.c
@@ -642,6 +642,33 @@ static ssize_t update_interval_store(struct device *dev,
 	return count;
 }
 
+static ssize_t repeatability_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	struct sht3x_data *data = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", data->repeatability);
+}
+
+static ssize_t repeatability_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf,
+				     size_t count)
+{
+	u8 val;
+	struct sht3x_data *data = dev_get_drvdata(dev);
+
+	val = kstrtou8(buf, 0, &val);
+	if (val)
+		return val;
+
+	val = clamp_val(val, low_repeatability, high_repeatability);
+	data->repeatability = val;
+
+	return count;
+}
+
 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp1_input, 0);
 static SENSOR_DEVICE_ATTR_RO(humidity1_input, humidity1_input, 0);
 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp1_limit, limit_max);
@@ -658,6 +685,7 @@ static SENSOR_DEVICE_ATTR_RO(temp1_alarm, temp1_alarm, 0);
 static SENSOR_DEVICE_ATTR_RO(humidity1_alarm, humidity1_alarm, 0);
 static SENSOR_DEVICE_ATTR_RW(heater_enable, heater_enable, 0);
 static SENSOR_DEVICE_ATTR_RW(update_interval, update_interval, 0);
+static SENSOR_DEVICE_ATTR_RW(repeatability, repeatability, 0);
 
 static struct attribute *sht3x_attrs[] = {
 	&sensor_dev_attr_temp1_input.dev_attr.attr,
@@ -674,6 +702,7 @@ static struct attribute *sht3x_attrs[] = {
 	&sensor_dev_attr_humidity1_alarm.dev_attr.attr,
 	&sensor_dev_attr_heater_enable.dev_attr.attr,
 	&sensor_dev_attr_update_interval.dev_attr.attr,
+	&sensor_dev_attr_repeatability.dev_attr.attr,
 	NULL
 };
 
-- 
2.30.2