[RFC PATCH 1/2] hwmon: (sht3x) convert some of sysfs interface to hwmon

[JuenKit Yip]

update_interval, temperature/humidity max/min and hyst
were moved to new hwmon interface, and only heater and
repeatability were reserved as non-stardard sysfs interface.

Signed-off-by: JuenKit Yip <JuenKit_Yip@xxxxxxxxxxx>
---
 drivers/hwmon/sht3x.c | 351 ++++++++++++++++++++++++++++--------------
 1 file changed, 239 insertions(+), 112 deletions(-)

diff --git a/drivers/hwmon/sht3x.c b/drivers/hwmon/sht3x.c
index bf1863061..31013b5b6 100644
--- a/drivers/hwmon/sht3x.c
+++ b/drivers/hwmon/sht3x.c
@@ -147,6 +147,37 @@ static const u16 mode_to_update_interval[] = {
 	 100,
 };
 
+static const struct hwmon_channel_info * const sht3x_channel_info[] = {
+	HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL),
+	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MIN |
+				HWMON_T_MIN_HYST | HWMON_T_MAX |
+				HWMON_T_MAX_HYST | HWMON_T_ALARM),
+	HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT | HWMON_H_MIN |
+				HWMON_H_MIN_HYST | HWMON_H_MAX |
+				HWMON_H_MAX_HYST | HWMON_H_ALARM),
+	NULL,
+};
+
+static const struct i2c_device_id sht3x_ids[];
+
+static umode_t sht3x_is_visible(const void *data, enum hwmon_sensor_types type,
+				u32 attr, int channel);
+static int sht3x_read(struct device *dev, enum hwmon_sensor_types type,
+		      u32 attr, int channel, long *val);
+static int sht3x_write(struct device *dev, enum hwmon_sensor_types type,
+		       u32 attr, int channel, long val);
+
+static const struct hwmon_ops sht3x_ops = {
+	.is_visible = sht3x_is_visible,
+	.read = sht3x_read,
+	.write = sht3x_write,
+};
+
+static const struct hwmon_chip_info sht3x_chip_info = {
+	.ops = &sht3x_ops,
+	.info = sht3x_channel_info,
+};
+
 struct sht3x_data {
 	struct i2c_client *client;
 	struct mutex i2c_lock; /* lock for sending i2c commands */
@@ -277,26 +308,24 @@ static struct sht3x_data *sht3x_update_client(struct device *dev)
 }
 
 /* sysfs attributes */
-static ssize_t temp1_input_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
+static int temp1_input_show(struct device *dev)
 {
 	struct sht3x_data *data = sht3x_update_client(dev);
 
 	if (IS_ERR(data))
 		return PTR_ERR(data);
 
-	return sprintf(buf, "%d\n", data->temperature);
+	return data->temperature;
 }
 
-static ssize_t humidity1_input_show(struct device *dev,
-				    struct device_attribute *attr, char *buf)
+static int humidity1_input_show(struct device *dev)
 {
 	struct sht3x_data *data = sht3x_update_client(dev);
 
 	if (IS_ERR(data))
 		return PTR_ERR(data);
 
-	return sprintf(buf, "%u\n", data->humidity);
+	return data->humidity;
 }
 
 /*
@@ -332,33 +361,24 @@ static int limits_update(struct sht3x_data *data)
 	return ret;
 }
 
-static ssize_t temp1_limit_show(struct device *dev,
-				struct device_attribute *attr,
-				char *buf)
+static int temp1_limit_show(struct device *dev, int index)
 {
 	struct sht3x_data *data = dev_get_drvdata(dev);
-	u8 index = to_sensor_dev_attr(attr)->index;
-	int temperature_limit = data->temperature_limits[index];
 
-	return sysfs_emit(buf, "%d\n", temperature_limit);
+	return data->temperature_limits[index];
 }
 
-static ssize_t humidity1_limit_show(struct device *dev,
-				    struct device_attribute *attr,
-				    char *buf)
+static ssize_t humidity1_limit_show(struct device *dev, int index)
 {
 	struct sht3x_data *data = dev_get_drvdata(dev);
-	u8 index = to_sensor_dev_attr(attr)->index;
-	u32 humidity_limit = data->humidity_limits[index];
 
-	return sysfs_emit(buf, "%u\n", humidity_limit);
+	return data->humidity_limits[index];
 }
 
 /*
  * limit_store must only be called with data_lock held
  */
 static size_t limit_store(struct device *dev,
-			  size_t count,
 			  u8 index,
 			  int temperature,
 			  u32 humidity)
@@ -400,50 +420,42 @@ static size_t limit_store(struct device *dev,
 
 	data->temperature_limits[index] = temperature;
 	data->humidity_limits[index] = humidity;
-	return count;
+	return 0;
 }
 
-static ssize_t temp1_limit_store(struct device *dev,
-				 struct device_attribute *attr,
-				 const char *buf,
-				 size_t count)
+static int temp1_limit_store(struct device *dev, int index, const char *val)
 {
 	int temperature;
 	int ret;
 	struct sht3x_data *data = dev_get_drvdata(dev);
-	u8 index = to_sensor_dev_attr(attr)->index;
 
-	ret = kstrtoint(buf, 0, &temperature);
+	ret = kstrtoint(val, 0, &temperature);
 	if (ret)
 		return ret;
 
 	temperature = clamp_val(temperature, SHT3X_MIN_TEMPERATURE,
 				SHT3X_MAX_TEMPERATURE);
 	mutex_lock(&data->data_lock);
-	ret = limit_store(dev, count, index, temperature,
+	ret = limit_store(dev, index, temperature,
 			  data->humidity_limits[index]);
 	mutex_unlock(&data->data_lock);
 
-	return ret;
+	return 0;
 }
 
-static ssize_t humidity1_limit_store(struct device *dev,
-				     struct device_attribute *attr,
-				     const char *buf,
-				     size_t count)
+static ssize_t humidity1_limit_store(struct device *dev, int index, const char *val)
 {
 	u32 humidity;
 	int ret;
 	struct sht3x_data *data = dev_get_drvdata(dev);
-	u8 index = to_sensor_dev_attr(attr)->index;
 
-	ret = kstrtou32(buf, 0, &humidity);
+	ret = kstrtou32(val, 0, &humidity);
 	if (ret)
 		return ret;
 
 	humidity = clamp_val(humidity, SHT3X_MIN_HUMIDITY, SHT3X_MAX_HUMIDITY);
 	mutex_lock(&data->data_lock);
-	ret = limit_store(dev, count, index, data->temperature_limits[index],
+	ret = limit_store(dev, index, data->temperature_limits[index],
 			  humidity);
 	mutex_unlock(&data->data_lock);
 
@@ -474,7 +486,6 @@ static void sht3x_select_command(struct sht3x_data *data)
 }
 
 static int status_register_read(struct device *dev,
-				struct device_attribute *attr,
 				char *buffer, int length)
 {
 	int ret;
@@ -487,34 +498,30 @@ static int status_register_read(struct device *dev,
 	return ret;
 }
 
-static ssize_t temp1_alarm_show(struct device *dev,
-				struct device_attribute *attr,
-				char *buf)
+static int temp1_alarm_show(struct device *dev)
 {
 	char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
 	int ret;
 
-	ret = status_register_read(dev, attr, buffer,
+	ret = status_register_read(dev, buffer,
 				   SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
 	if (ret)
 		return ret;
 
-	return sysfs_emit(buf, "%d\n", !!(buffer[0] & 0x04));
+	return !!(buffer[0] & 0x04);
 }
 
-static ssize_t humidity1_alarm_show(struct device *dev,
-				    struct device_attribute *attr,
-				    char *buf)
+static int humidity1_alarm_show(struct device *dev)
 {
 	char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
 	int ret;
 
-	ret = status_register_read(dev, attr, buffer,
+	ret = status_register_read(dev, buffer,
 				   SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
 	if (ret)
 		return ret;
 
-	return sysfs_emit(buf, "%d\n", !!(buffer[0] & 0x08));
+	return !!(buffer[0] & 0x08);
 }
 
 static ssize_t heater_enable_show(struct device *dev,
@@ -524,7 +531,7 @@ static ssize_t heater_enable_show(struct device *dev,
 	char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
 	int ret;
 
-	ret = status_register_read(dev, attr, buffer,
+	ret = status_register_read(dev, buffer,
 				   SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
 	if (ret)
 		return ret;
@@ -560,20 +567,14 @@ static ssize_t heater_enable_store(struct device *dev,
 	return ret;
 }
 
-static ssize_t update_interval_show(struct device *dev,
-				    struct device_attribute *attr,
-				    char *buf)
+static int update_interval_show(struct device *dev)
 {
 	struct sht3x_data *data = dev_get_drvdata(dev);
 
-	return sysfs_emit(buf, "%u\n",
-			 mode_to_update_interval[data->mode]);
+	return mode_to_update_interval[data->mode];
 }
 
-static ssize_t update_interval_store(struct device *dev,
-				     struct device_attribute *attr,
-				     const char *buf,
-				     size_t count)
+static int update_interval_store(struct device *dev, const char *val)
 {
 	u16 update_interval;
 	u8 mode;
@@ -582,7 +583,7 @@ static ssize_t update_interval_store(struct device *dev,
 	struct sht3x_data *data = dev_get_drvdata(dev);
 	struct i2c_client *client = data->client;
 
-	ret = kstrtou16(buf, 0, &update_interval);
+	ret = kstrtou16(val, 0, &update_interval);
 	if (ret)
 		return ret;
 
@@ -592,7 +593,7 @@ static ssize_t update_interval_store(struct device *dev,
 	/* mode did not change */
 	if (mode == data->mode) {
 		mutex_unlock(&data->data_lock);
-		return count;
+		return 0;
 	}
 
 	mutex_lock(&data->i2c_lock);
@@ -634,7 +635,7 @@ static ssize_t update_interval_store(struct device *dev,
 	if (ret != SHT3X_CMD_LENGTH)
 		return ret < 0 ? ret : -EIO;
 
-	return count;
+	return 0;
 }
 
 static ssize_t repeatability_show(struct device *dev,
@@ -668,60 +669,191 @@ static ssize_t repeatability_store(struct device *dev,
 	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);
-static SENSOR_DEVICE_ATTR_RW(humidity1_max, humidity1_limit, limit_max);
-static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, temp1_limit, limit_max_hyst);
-static SENSOR_DEVICE_ATTR_RW(humidity1_max_hyst, humidity1_limit,
-			     limit_max_hyst);
-static SENSOR_DEVICE_ATTR_RW(temp1_min, temp1_limit, limit_min);
-static SENSOR_DEVICE_ATTR_RW(humidity1_min, humidity1_limit, limit_min);
-static SENSOR_DEVICE_ATTR_RW(temp1_min_hyst, temp1_limit, limit_min_hyst);
-static SENSOR_DEVICE_ATTR_RW(humidity1_min_hyst, humidity1_limit,
-			     limit_min_hyst);
-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,
-	&sensor_dev_attr_humidity1_input.dev_attr.attr,
-	&sensor_dev_attr_temp1_max.dev_attr.attr,
-	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
-	&sensor_dev_attr_humidity1_max.dev_attr.attr,
-	&sensor_dev_attr_humidity1_max_hyst.dev_attr.attr,
-	&sensor_dev_attr_temp1_min.dev_attr.attr,
-	&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
-	&sensor_dev_attr_humidity1_min.dev_attr.attr,
-	&sensor_dev_attr_humidity1_min_hyst.dev_attr.attr,
-	&sensor_dev_attr_temp1_alarm.dev_attr.attr,
-	&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
-};
-
-static struct attribute *sts3x_attrs[] = {
-	&sensor_dev_attr_temp1_input.dev_attr.attr,
-	&sensor_dev_attr_temp1_max.dev_attr.attr,
-	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
-	&sensor_dev_attr_temp1_min.dev_attr.attr,
-	&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
-	&sensor_dev_attr_temp1_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
 };
 
 ATTRIBUTE_GROUPS(sht3x);
-ATTRIBUTE_GROUPS(sts3x);
 
-static const struct i2c_device_id sht3x_ids[];
+static umode_t sht3x_is_visible(const void *data, enum hwmon_sensor_types type,
+				u32 attr, int channel)
+{
+	const struct sht3x_data *chip_data = data;
+	struct i2c_client *client = chip_data->client;
+
+	switch (type) {
+	case hwmon_chip:
+		switch (attr) {
+		case hwmon_chip_update_interval:
+			return 0644;
+		default:
+			return -EINVAL;
+		}
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+		case hwmon_temp_alarm:
+			return 0444;
+		case hwmon_temp_max:
+		case hwmon_temp_max_hyst:
+		case hwmon_temp_min:
+		case hwmon_temp_min_hyst:
+			return 0644;
+		default:
+			return -EINVAL;
+		}
+	case hwmon_humidity:
+		if (i2c_match_id(sht3x_ids, client)->driver_data == sts3x)
+			return 0;
+		switch (attr) {
+		case hwmon_humidity_input:
+		case hwmon_humidity_alarm:
+			return 0444;
+		case hwmon_humidity_max:
+		case hwmon_humidity_max_hyst:
+		case hwmon_humidity_min:
+		case hwmon_humidity_min_hyst:
+			return 0644;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int sht3x_read(struct device *dev, enum hwmon_sensor_types type,
+		      u32 attr, int channel, long *val)
+{
+	enum sht3x_limits index;
+
+	switch (type) {
+	case hwmon_chip:
+		switch (attr) {
+		case hwmon_chip_update_interval:
+			*val = update_interval_show(dev);
+			break;
+		default:
+			return -EINVAL;
+		}
+		break;
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+			*val = temp1_input_show(dev);
+			return 0;
+		case hwmon_temp_alarm:
+			*val = temp1_alarm_show(dev);
+			return 0;
+		case hwmon_temp_max:
+			index = limit_max;
+			break;
+		case hwmon_temp_max_hyst:
+			index = limit_max_hyst;
+			break;
+		case hwmon_temp_min:
+			index = limit_min;
+			break;
+		case hwmon_temp_min_hyst:
+			index = limit_min_hyst;
+			break;
+		default:
+			return -EINVAL;
+		}
+		*val = temp1_limit_show(dev, index);
+		return 0;
+	case hwmon_humidity:
+		switch (attr) {
+		case hwmon_humidity_input:
+			*val = humidity1_input_show(dev);
+			return 0;
+		case hwmon_humidity_alarm:
+			*val = humidity1_alarm_show(dev);
+			return 0;
+		case hwmon_humidity_max:
+			index = limit_max;
+			break;
+		case hwmon_humidity_max_hyst:
+			index = limit_max_hyst;
+			break;
+		case hwmon_humidity_min:
+			index = limit_min;
+			break;
+		case hwmon_humidity_min_hyst:
+			index = limit_min_hyst;
+			break;
+		default:
+			return -EINVAL;
+		}
+		*val = humidity1_limit_show(dev, index);
+		return 0;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int sht3x_write(struct device *dev, enum hwmon_sensor_types type,
+		       u32 attr, int channel, long val)
+{
+	enum sht3x_limits index;
+
+	switch (type) {
+	case hwmon_chip:
+		switch (attr) {
+		case hwmon_chip_update_interval:
+			return update_interval_store(dev, (const char *)&val);
+		default:
+			return -EINVAL;
+		}
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_max:
+			index = limit_max;
+			break;
+		case hwmon_temp_max_hyst:
+			index = limit_max_hyst;
+			break;
+		case hwmon_temp_min:
+			index = limit_min;
+			break;
+		case hwmon_temp_min_hyst:
+			index = limit_min_hyst;
+			break;
+		default:
+			return -EINVAL;
+		}
+		return temp1_limit_store(dev, index, (const char *)&val);
+	case hwmon_humidity:
+		switch (attr) {
+		case hwmon_humidity_max:
+			index = limit_max;
+			break;
+		case hwmon_humidity_max_hyst:
+			index = limit_max_hyst;
+			break;
+		case hwmon_humidity_min:
+			index = limit_min;
+			break;
+		case hwmon_humidity_min_hyst:
+			index = limit_min_hyst;
+			break;
+		default:
+			return -EINVAL;
+		}
+		return humidity1_limit_store(dev, index, (const char *)val);
+	default:
+		return -EINVAL;
+	}
+}
 
 static int sht3x_probe(struct i2c_client *client)
 {
@@ -730,7 +862,6 @@ static int sht3x_probe(struct i2c_client *client)
 	struct device *hwmon_dev;
 	struct i2c_adapter *adap = client->adapter;
 	struct device *dev = &client->dev;
-	const struct attribute_group **attribute_groups;
 
 	/*
 	 * we require full i2c support since the sht3x uses multi-byte read and
@@ -771,15 +902,11 @@ static int sht3x_probe(struct i2c_client *client)
 	if (ret)
 		return ret;
 
-	if (i2c_match_id(sht3x_ids, client)->driver_data == sts3x)
-		attribute_groups = sts3x_groups;
-	else
-		attribute_groups = sht3x_groups;
-
-	hwmon_dev = devm_hwmon_device_register_with_groups(dev,
-							   client->name,
-							   data,
-							   attribute_groups);
+	hwmon_dev = devm_hwmon_device_register_with_info(dev,
+							 client->name,
+							 data,
+							 &sht3x_chip_info,
+							 sht3x_groups);
 
 	if (IS_ERR(hwmon_dev))
 		dev_dbg(dev, "unable to register hwmon device\n");
-- 
2.30.2