Re: [PATCH v2 2/2] iio: adc: ti-ads1015: Add support for label

[David Lechner <dlechner@baylibre.com>]

On 9/2/26 12:22 PM, Flaviu Nistor wrote:
> Add support for label sysfs attribute similar to other adc devices. This is
> particularly useful because the label can match the schematic signal name,
> identifying channel voltages easier if label is defined via device tree.
> 
> Signed-off-by: Flaviu Nistor <flaviu.nistor@gmail.com>
> ---
> Changes in v2:
> - Implement changes suggested by Andy Shevchenko. 
> - Link to v1: https://lore.kernel.org/all/20260901184302.8127-2-flaviu.nistor@gmail.com/
> 
>  drivers/iio/adc/ti-ads1015.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
> index 0fbfa4e499aa..8be1f0c32ca9 100644
> --- a/drivers/iio/adc/ti-ads1015.c
> +++ b/drivers/iio/adc/ti-ads1015.c
> @@ -233,6 +233,7 @@ static const struct iio_event_spec ads1015_events[] = {
>  struct ads1015_channel_data {
>  	unsigned int pga;
>  	unsigned int data_rate;
> +	const char *label;
>  };
>  
>  struct ads1015_thresh_data {
> @@ -586,6 +587,15 @@ static int ads1015_read_raw(struct iio_dev *indio_dev,
>  	}
>  }
>  
> +static int ads1015_read_label(struct iio_dev *indio_dev,
> +			      struct iio_chan_spec const *chan, char *label)
> +{
> +	struct ads1015_data *data = iio_priv(indio_dev);
> +	const char *name = data->channel_data[chan->address].label;
> +
> +	return sysfs_emit(label, "%s\n", name);
> +}
> +
>  static int ads1015_write_raw(struct iio_dev *indio_dev,
>  			     struct iio_chan_spec const *chan, int val,
>  			     int val2, long mask)
> @@ -843,6 +853,7 @@ static const struct iio_buffer_setup_ops ads1015_buffer_setup_ops = {
>  static const struct iio_info ads1015_info = {
>  	.read_avail	= ads1015_read_avail,
>  	.read_raw	= ads1015_read_raw,
> +	.read_label	= ads1015_read_label,
>  	.write_raw	= ads1015_write_raw,
>  	.read_event_value = ads1015_read_event,
>  	.write_event_value = ads1015_write_event,
> @@ -853,6 +864,7 @@ static const struct iio_info ads1015_info = {
>  static const struct iio_info tla2024_info = {
>  	.read_avail	= ads1015_read_avail,
>  	.read_raw	= ads1015_read_raw,
> +	.read_label	= ads1015_read_label,
>  	.write_raw	= ads1015_write_raw,
>  };
>  
> @@ -861,7 +873,9 @@ static int ads1015_client_get_channels_config(struct i2c_client *client)
>  	struct iio_dev *indio_dev = i2c_get_clientdata(client);
>  	struct ads1015_data *data = iio_priv(indio_dev);
>  	struct device *dev = &client->dev;
> +	const char *label;
>  	int i = -1;
> +	int ret;
>  
>  	device_for_each_child_node_scoped(dev, node) {
>  		u32 pval;
> @@ -897,6 +911,17 @@ static int ads1015_client_get_channels_config(struct i2c_client *client)
>  			}
>  		}
>  
> +		if (fwnode_property_present(node, "label")) {
> +			ret = fwnode_property_read_string(node, "label", &label);
> +			if (ret) {
> +				dev_err(dev, "invalid label on %pfw\n", node);
> +				return ret;
> +			}
> +			data->channel_data[channel].label = label;
> +		} else {
> +			data->channel_data[channel].label = "";

I think the normal way to do this is to return -EINVAL on channels with no
label rather than an empty string.

> +		}
> +
>  		data->channel_data[channel].pga = pga;
>  		data->channel_data[channel].data_rate = data_rate;
>