Re: [PATCH v2 4/4] iio: adc: ad4080: add support for AD4880 dual-channel ADC

[Nuno Sá]

On Fri, 2026-02-06 at 18:07 +0200, Antoniu Miclaus wrote:
> Add support for the AD4880, a dual-channel 20-bit 40MSPS SAR ADC with
> integrated fully differential amplifiers (FDA).
> 
> The AD4880 has two independent ADC channels, each with its own SPI
> configuration interface. The driver uses spi_new_ancillary_device() to
> create an additional SPI device for the second channel, allowing both
> channels to share the same SPI bus with different chip selects.
> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>
> ---

...

> 
> -	ret = devm_iio_backend_enable(dev, st->back);
> +	/*
> +	 * Request buffer from the first backend only. For multi-channel
> +	 * devices (e.g., AD4880), all backends share a single IIO buffer
> +	 * as data from all ADC channels is interleaved into one stream.
> +	 */
> +	ret = devm_iio_backend_request_buffer(dev, st->back[0], indio_dev);
>  	if (ret)
>  		return ret;

Ahh that's a pitty. When I read the cover, I thought we would finally have a multi
buffer user so we could fix some issues with it :)

- Nuno Sá