Re: [PATCH v12 9/9] iio: adc: ad4851: add ad485x driver

[David Lechner <dlechner@baylibre.com>]

On 2/7/25 8:09 AM, Antoniu Miclaus wrote:
> Add support for the AD485X a fully buffered, 8-channel simultaneous
> sampling, 16/20-bit, 1 MSPS data acquisition system (DAS) with
> differential, wide common-mode range inputs.
> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
> ---

...

> +static int ad4851_parse_channels_common(struct iio_dev *indio_dev,
> +					struct iio_chan_spec **chans,
> +					const struct iio_chan_spec ad4851_chan)
> +{
> +	struct ad4851_state *st = iio_priv(indio_dev);
> +	struct device *dev = &st->spi->dev;
> +	struct iio_chan_spec *channels, *chan_start;
> +	unsigned int num_channels, reg;
> +	unsigned int index = 0;
> +	int ret;
> +
> +	num_channels = device_get_child_node_count(dev);
> +	if (num_channels > AD4851_MAX_CH_NR)
> +		return dev_err_probe(dev, -EINVAL, "Too many channels: %u\n",
> +				     num_channels);
> +
> +	channels = devm_kcalloc(dev, num_channels, sizeof(*channels), GFP_KERNEL);
> +	if (!channels)
> +		return -ENOMEM;
> +
> +	chan_start = channels;
> +
> +	device_for_each_child_node_scoped(dev, child) {
> +		ret = fwnode_property_read_u32(child, "reg", &reg);
> +		if (ret)
> +			return dev_err_probe(dev, ret,
> +					     "Missing channel number\n");
> +		if (reg >= AD4851_MAX_CH_NR)
> +			return dev_err_probe(dev, ret,

ret will be == 0 here, so need to replace with -EINVAL.

> +					     "Invalid channel number\n");