Re: [PATCH v5 10/20] iio: adc: ad7768: Add sampling frequency controls

[Andy Shevchenko]

On Fri, Aug 28, 2026 at 05:30:33PM +0200, Janani Sunil wrote:
> Expose the requested sampling frequency and available rates for each
> channel. Validate requests against the rates supported by the power mode
> tables and apply them when buffered capture starts.

...

> struct ad7768_state {

>  	unsigned int power_mode_idx;
>  	const struct ad7768_chip_info *chip_info;
>  	struct ad7768_avail_freq avail_freq[ARRAY_SIZE(ad7768_power_modes)];
> +	unsigned int n_freqs;
> +	int freqs[AD7768_MAX_FREQS];
>  	unsigned int ch_freq[AD7768_MAX_CHANNEL];
>  	struct iio_backend *back;
>  	unsigned int vref_uV[2];

Just double check with `pahole` that this is optimal layout.

>  };

...

>  {
>  	struct ad7768_state *st = iio_priv(indio_dev);
> -	unsigned int vref_idx;
>  
> -	if (info != IIO_CHAN_INFO_SCALE)
> +	switch (info) {
> +	case IIO_CHAN_INFO_SCALE: {
> +		unsigned int vref_idx;
> +
> +		vref_idx = chan->channel >= st->chip_info->num_channels / 2;
> +		*val = 2 * st->vref_uV[vref_idx] / 1000;

1000 --> (MICRO / MILLI)

> +		*val2 = chan->scan_type.realbits;
> +
> +		return IIO_VAL_FRACTIONAL_LOG2;
> +	}
> +	case IIO_CHAN_INFO_SAMP_FREQ: {
> +		guard(mutex)(&st->lock);
> +		*val = st->ch_freq[chan->channel];
> +
> +		return IIO_VAL_INT;
> +	}
> +	default:
> +		return -EINVAL;
> +	}
> +}

-- 
With Best Regards,
Andy Shevchenko