Re: [PATCH v2 2/2] hwmon: (chipcap2) Add support for label

["Javier Carrasco" <javier.carrasco.cruz@gmail.com>]

On Thu Jun 25, 2026 at 6:04 PM CEST, Flaviu Nistor wrote:
> Add support for label sysfs attribute similar to other hwmon devices.
> This is particularly useful for systems with multiple sensors on the
> same board, where identifying individual sensors is much easier since
> labels can be defined via device tree.
>
> Signed-off-by: Flaviu Nistor <flaviu.nistor@gmail.com>
> ---
> Changes in v2:
> - No change for this patch in the patch series.
> - Link to v1: https://lore.kernel.org/all/20260622122200.14245-1-flaviu.nistor@gmail.com/
>
>  Documentation/hwmon/chipcap2.rst |  2 ++
>  drivers/hwmon/chipcap2.c         | 25 +++++++++++++++++++++++--
>  2 files changed, 25 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/hwmon/chipcap2.rst b/Documentation/hwmon/chipcap2.rst
> index dc165becc64c..c38d87b91b69 100644
> --- a/Documentation/hwmon/chipcap2.rst
> +++ b/Documentation/hwmon/chipcap2.rst
> @@ -70,4 +70,6 @@ humidity1_min_hyst:             RW      humidity low hystersis
>  humidity1_max_hyst:             RW      humidity high hystersis
>  humidity1_min_alarm:            RO      humidity low alarm indicator
>  humidity1_max_alarm:            RO      humidity high alarm indicator
> +humidity1_label:                RO      descriptive name for the sensor
> +temp1_label:                    RO      descriptive name for the sensor
>  =============================== ======= ========================================
> diff --git a/drivers/hwmon/chipcap2.c b/drivers/hwmon/chipcap2.c
> index 4aecf463180f..086571d556b7 100644
> --- a/drivers/hwmon/chipcap2.c
> +++ b/drivers/hwmon/chipcap2.c
> @@ -22,6 +22,8 @@
>  #include <linux/irq.h>
>  #include <linux/module.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/property.h>
>
>  #define CC2_START_CM			0xA0
>  #define CC2_START_NOM			0x80
> @@ -83,6 +85,7 @@ struct cc2_data {
>  	struct i2c_client *client;
>  	struct regulator *regulator;
>  	const char *name;
> +	const char *label;
>  	int irq_ready;
>  	int irq_low;
>  	int irq_high;
> @@ -449,6 +452,8 @@ static umode_t cc2_is_visible(const void *data, enum hwmon_sensor_types type,
>  		switch (attr) {
>  		case hwmon_humidity_input:
>  			return 0444;
> +		case hwmon_humidity_label:
> +			return cc2->label ? 0444 : 0;
>  		case hwmon_humidity_min_alarm:
>  			return cc2->rh_alarm.low_alarm_visible ? 0444 : 0;
>  		case hwmon_humidity_max_alarm:
> @@ -466,6 +471,8 @@ static umode_t cc2_is_visible(const void *data, enum hwmon_sensor_types type,
>  		switch (attr) {
>  		case hwmon_temp_input:
>  			return 0444;
> +		case hwmon_temp_label:
> +			return cc2->label ? 0444 : 0;
>  		default:
>  			return 0;
>  		}
> @@ -552,6 +559,16 @@ static int cc2_humidity_max_alarm_status(struct cc2_data *data, long *val)
>  	return 0;
>  }
>
> +static int cc2_read_string(struct device *dev, enum hwmon_sensor_types type,
> +			   u32 attr, int channel, const char **str)
> +{
> +	struct cc2_data *data = dev_get_drvdata(dev);
> +
> +	*str = data->label;
> +
> +	return 0;
> +}
> +
>  static int cc2_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
>  		    int channel, long *val)
>  {
> @@ -670,8 +687,9 @@ static int cc2_request_alarm_irqs(struct cc2_data *data, struct device *dev)
>  }
>
>  static const struct hwmon_channel_info *cc2_info[] = {
> -	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
> -	HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT | HWMON_H_MIN | HWMON_H_MAX |
> +	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_LABEL),
> +	HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT | HWMON_H_LABEL |
> +			   HWMON_H_MIN | HWMON_H_MAX |
>  			   HWMON_H_MIN_HYST | HWMON_H_MAX_HYST |
>  			   HWMON_H_MIN_ALARM | HWMON_H_MAX_ALARM),
>  	NULL
> @@ -680,6 +698,7 @@ static const struct hwmon_channel_info *cc2_info[] = {
>  static const struct hwmon_ops cc2_hwmon_ops = {
>  	.is_visible = cc2_is_visible,
>  	.read = cc2_read,
> +	.read_string = cc2_read_string,
>  	.write = cc2_write,
>  };
>
> @@ -710,6 +729,8 @@ static int cc2_probe(struct i2c_client *client)
>  		return dev_err_probe(dev, PTR_ERR(data->regulator),
>  				     "Failed to get regulator\n");
>
> +	device_property_read_string(dev, "label", &data->label);
> +
>  	ret = cc2_request_ready_irq(data, dev);
>  	if (ret)
>  		return dev_err_probe(dev, ret, "Failed to request ready irq\n");

Reviewed-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>