Re: [PATCH RFC v3 4/9] iio: frequency: ad9910: add digital ramp generator support

Jonathan Cameron
2026-04-26T12:05:56Z

On Fri, 17 Apr 2026 09:17:33 +0100
Rodrigo Alencar via B4 Relay <devnull+rodrigo.alencar.analog.com@kernel.org> wrote:

> From: Rodrigo Alencar <rodrigo.alencar@analog.com>
>
> Add DRG channels with destination selection (frequency, phase, or

I'd spell out Digital Ramp Generator here as well rather than
just in the patch title.

I'll come back to the comment below (probably) when looking at the
ABI documentation.

> amplitude) based on attribute writes, dwell mode control,
> configurable upper/lower limits, increment/decrement step sizes, and
> step rate settings.
>
> Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
> ---
> drivers/iio/frequency/ad9910.c | 425 ++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 423 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/frequency/ad9910.c b/drivers/iio/frequency/ad9910.c
> index 5b4076028a29..c9ec677cd63a 100644
> --- a/drivers/iio/frequency/ad9910.c
> +++ b/drivers/iio/frequency/ad9910.c

>
> +static const struct iio_chan_spec_ext_info ad9910_drg_ramp_ext_info[] = {
> + AD9910_DRG_EXT_INFO("frequency_step", AD9910_DRG_FREQ_STEP),
> + AD9910_DRG_EXT_INFO("phase_step", AD9910_DRG_PHASE_STEP),
> + AD9910_DRG_EXT_INFO("scale_step", AD9910_DRG_AMP_STEP),

For things that are tidied to a clock rate we normally try to express
then in terms of time rather than ticks / steps as that's what the
user normally cares about. Anyhow I'll come back to this with the
documentation patch review.

> + { }
> +};