Re: [PATCH v3 3/3] iio: adc: qcom-pm8xxx-xoadc: add support for reading channel labels

Andy Shevchenko
2026-04-06T19:46:35Z

On Sun, Apr 05, 2026 at 04:52:21PM +0000, Antony Kurniawan Soemardi wrote:
> Implement the .read_label callback to allow userspace to identify ADC
> channels via the "label" property in the device tree. The name field in
> pm8xxx_chan_info is renamed to label to better reflect its purpose. If
> no label is provided in the device tree, it defaults to the hardware
> datasheet name.

> The change has been tested on Sony Xperia SP (PM8921).

...

> +static int pm8xxx_read_label(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, char *label)
> +{
> + struct pm8xxx_xoadc *adc = iio_priv(indio_dev);

> + struct pm8xxx_chan_info *ch = pm8xxx_get_channel(adc, chan->address);

When you have a validation the better style is to split definition and
assignment. This makes code robust against (theoretically) possible changes
that might reuse the same variable for something else.

> + if (!ch)
> + return -EINVAL;
> + return sysfs_emit(label, "%s\n", ch->label);
> +}

Again, no need to resend now, just make it in the next version if that version
is asked for.

--
With Best Regards,
Andy Shevchenko