Re: [PATCH v10 3/8] iio: backend: add API for oversampling

[Nuno Sá]

On Fri, 2025-01-17 at 15:06 +0200, Antoniu Miclaus wrote:
> Add backend support for setting oversampling ratio.
> 
> Reviewed-by: David Lechner <dlechner@xxxxxxxxxxxx>
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>
> ---
> no changes in v10.
>  drivers/iio/industrialio-backend.c | 15 +++++++++++++++
>  include/linux/iio/backend.h        |  5 +++++
>  2 files changed, 20 insertions(+)
> 
> diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-
> backend.c
> index 2088afa7a55c..d4ad36f54090 100644
> --- a/drivers/iio/industrialio-backend.c
> +++ b/drivers/iio/industrialio-backend.c
> @@ -681,6 +681,21 @@ int iio_backend_data_size_set(struct iio_backend *back,
> unsigned int size)
>  }
>  EXPORT_SYMBOL_NS_GPL(iio_backend_data_size_set, "IIO_BACKEND");
>  
> +/**
> + * iio_backend_oversampling_ratio_set - set the oversampling ratio
> + * @back: Backend device
> + * @ratio: The oversampling ratio - value 1 corresponds to no oversampling.
> + *
> + * Return:
> + * 0 on success, negative error number on failure.
> + */
> +int iio_backend_oversampling_ratio_set(struct iio_backend *back,
> +				       unsigned int ratio)
> +{
> +	return iio_backend_op_call(back, oversampling_ratio_set, ratio);
> +}
> +EXPORT_SYMBOL_NS_GPL(iio_backend_oversampling_ratio_set, "IIO_BACKEND");
> +

Hmm, I'm very late to the party so don't bother in sending another revision
unless you have too. But if you do, I would prefer to have this through a
write_raw() interface. Meaning we would only have write_raw() as a backend op
and  then you could add this as a convenient inline helper built on top of
write_raw(). So this would be inline with what happens with read_raw(). Anyways,
we can clean it up afterwards since we already have a .set_sample_rate() op that
could use a similar approach.

- Nuno Sá