Re: [PATCH 1/3] hwmon: (sht3x) convert some of sysfs interface to hwmon

[Guenter Roeck]

On 6/24/23 09:01, JuenKit_Yip@xxxxxxxxxxx wrote:
> From: JuenKit Yip <JuenKit_Yip@xxxxxxxxxxx>
>
> 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>

Please version your patches and provide change logs.

> ---
>   drivers/hwmon/sht3x.c | 359 ++++++++++++++++++++++++++++--------------
>   1 file changed, 244 insertions(+), 115 deletions(-)
>
> diff --git a/drivers/hwmon/sht3x.c b/drivers/hwmon/sht3x.c
> index bf18630619e0..9b2dadd11eeb 100644
> --- a/drivers/hwmon/sht3x.c
> +++ b/drivers/hwmon/sht3x.c
> @@ -147,6 +147,19 @@ 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[];
> +

Again, please avoid forward declarations. More on that below.

>   struct sht3x_data {
>   	struct i2c_client *client;
>   	struct mutex i2c_lock; /* lock for sending i2c commands */
> @@ -276,27 +289,24 @@ static struct sht3x_data *sht3x_update_client(struct device *dev)
>   	return data;
>   }
>   
> -/* sysfs attributes */
> -static ssize_t temp1_input_show(struct device *dev,
> -				struct device_attribute *attr, char *buf)
> +static int temp1_input_read(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_read(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 +342,24 @@ 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_read(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 int humidity1_limit_read(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
> + * limit_write must only be called with data_lock held
>    */
> -static size_t limit_store(struct device *dev,
> -			  size_t count,
> +static size_t limit_write(struct device *dev,
>   			  u8 index,
>   			  int temperature,
>   			  u32 humidity)
> @@ -379,7 +380,7 @@ static size_t limit_store(struct device *dev,
>   	 * ST = (T + 45) / 175 * 2^16
>   	 * SRH = RH / 100 * 2^16
>   	 * adapted for fixed point arithmetic and packed the same as
> -	 * in limit_show()
> +	 * in limit_read()
>   	 */
>   	raw = ((u32)(temperature + 45000) * 24543) >> (16 + 7);
>   	raw |= ((humidity * 42950) >> 16) & 0xfe00;
> @@ -400,50 +401,43 @@ 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_write(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_write(dev, index, temperature,
>   			  data->humidity_limits[index]);
>   	mutex_unlock(&data->data_lock);
>   
>   	return ret;
>   }
>   
> -static ssize_t humidity1_limit_store(struct device *dev,
> -				     struct device_attribute *attr,
> -				     const char *buf,
> -				     size_t count)
> +static int humidity1_limit_write(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_write(dev, index, data->temperature_limits[index],
>   			  humidity);
>   	mutex_unlock(&data->data_lock);
>   
> @@ -474,7 +468,6 @@ 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 +480,30 @@ 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_read(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_read(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 +513,7 @@ 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 +549,14 @@ 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_read(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_write(struct device *dev, const char *val)
>   {
>   	u16 update_interval;
>   	u8 mode;
> @@ -582,7 +565,7 @@ 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 +575,7 @@ 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 +617,7 @@ 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 +651,211 @@ 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:
> +			break;
> +		}
> +		break;
> +	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:
> +			break;
> +		}
> +		break;
> +	case hwmon_humidity:
> +		if (i2c_match_id(sht3x_ids, client)->driver_data == sts3x)

It would be better to save the chip id in struct sht3x_data to avoid
having to dereference driver_data here, and to avoid needing a pointer
to struct i2c_client.

> +			return 0;

Maybe break; for consistency.

> +		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:
> +			break;
> +		}
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +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_read(dev);
> +			break;
> +		default:
> +			return -EOPNOTSUPP;
> +		}
> +		break;
> +	case hwmon_temp:
> +		switch (attr) {
> +		case hwmon_temp_input:
> +			*val = temp1_input_read(dev);
> +			break;
> +		case hwmon_temp_alarm:
> +			*val = temp1_alarm_read(dev);
> +			break;
> +		case hwmon_temp_max:
> +			index = limit_max;
> +			*val = temp1_limit_read(dev, index);
> +			break;
> +		case hwmon_temp_max_hyst:
> +			index = limit_max_hyst;
> +			*val = temp1_limit_read(dev, index);
> +			break;
> +		case hwmon_temp_min:
> +			index = limit_min;
> +			*val = temp1_limit_read(dev, index);
> +			break;
> +		case hwmon_temp_min_hyst:
> +			index = limit_min_hyst;
> +			*val = temp1_limit_read(dev, index);
> +			break;
> +		default:
> +			return -EOPNOTSUPP;
> +		}
> +		break;
> +	case hwmon_humidity:
> +		switch (attr) {
> +		case hwmon_humidity_input:
> +			*val = humidity1_input_read(dev);
> +			break;
> +		case hwmon_humidity_alarm:
> +			*val = humidity1_alarm_read(dev);
> +			break;
> +		case hwmon_humidity_max:
> +			index = limit_max;
> +			*val = humidity1_limit_read(dev, index);
> +			break;
> +		case hwmon_humidity_max_hyst:
> +			index = limit_max_hyst;
> +			*val = humidity1_limit_read(dev, index);
> +			break;
> +		case hwmon_humidity_min:
> +			index = limit_min;
> +			*val = humidity1_limit_read(dev, index);
> +			break;
> +		case hwmon_humidity_min_hyst:
> +			index = limit_min_hyst;
> +			*val = humidity1_limit_read(dev, index);
> +			break;
> +		default:
> +			return -EOPNOTSUPP;
> +		}
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	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_write(dev, (const char *)&val);
> +		default:
> +			return -EOPNOTSUPP;
> +		}
> +	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 -EOPNOTSUPP;
> +		}
> +		return temp1_limit_write(dev, index, (const char *)&val);

This does not work. The val parameter passed to the write function
is already the value, not a pointer to a string. There is no need
to parse it again, and trying to do so will fail (or, with bad luck,
crash).

Guenter

> +	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 -EOPNOTSUPP;
> +		}
> +		return humidity1_limit_write(dev, index, (const char *)val);
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +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,
> +};
>   
>   static int sht3x_probe(struct i2c_client *client)
>   {
> @@ -730,7 +864,6 @@ 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 +904,11 @@ 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");