Re: [PATCH v2] iio: dac: mcp4821: add configurable gain support

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 26 Mar 2026 12:42:42 +0530
Nikhil Gautam <nikhilgtr@gmail.com> wrote:

> Add support for configuring the DAC gain using the GA bit.
> Expose gain control via IIO_CHAN_INFO_CALIBSCALE.
> 
> Scale is updated dynamically based on selected gain:
> - 1x gain → 2.048V full-scale
> - 2x gain → 4.096V full-scale
> 
> Signed-off-by: Nikhil Gautam <nikhilgtr@gmail.com>
Just one small thing from me.

>  static int mcp4821_probe(struct spi_device *spi)
> @@ -177,12 +235,15 @@ static int mcp4821_probe(struct spi_device *spi)
>  	const struct mcp4821_chip_info *info;
>  
>  	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));
> -	if (indio_dev == NULL)
> +	if (!indio_dev)

Not related to rest of the patch. So doesn't belong in here.
Also generally not worth the noise of changing these.

>  		return -ENOMEM;
>  
>  	state = iio_priv(indio_dev);
>  	state->spi = spi;
>  
> +	/* default gain is 2x as GA bit is active low*/
> +	state->gain_1x = false;
> +
>  	info = spi_get_device_match_data(spi);
>  	indio_dev->name = info->name;
>  	indio_dev->info = &mcp4821_info;