Re: [PATCH] iio: frequency: Use SLEEP bit instead of RESET to disable output

[Gabriel Shahrouzi]

On Fri, Apr 18, 2025 at 11:40 AM Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
>
> On Thu, 17 Apr 2025 09:54:34 -0400
> Gabriel Shahrouzi <gshahrouzi@xxxxxxxxx> wrote:
>
> > According to the AD9832 datasheet (Table 10, D12 description), setting
> > the RESET bit forces the phase accumulator to zero, which corresponds to
> > a full-scale DC output, rather than disabling the output signal.
> >
> > The correct way to disable the output and enter a low-power state is to
> > set the AD9832_SLEEP bit (Table 10, D13 description), which powers down
> > the internal DAC current sources and disables internal clocks.
> >
> > Fixes: ea707584bac1 ("Staging: IIO: DDS: AD9832 / AD9835 driver")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Gabriel Shahrouzi <gshahrouzi@xxxxxxxxx>
> > ---
> Seems reasonable but I'd like some more review of this before picking it up.
> So feel free to poke me if nothing happens in say 2 weeks from now.
Sounds good.
>
> >  drivers/staging/iio/frequency/ad9832.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
> > index db42810c7664b..0872ff4ec4896 100644
> > --- a/drivers/staging/iio/frequency/ad9832.c
> > +++ b/drivers/staging/iio/frequency/ad9832.c
> > @@ -232,7 +232,7 @@ static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
> >                       st->ctrl_src &= ~(AD9832_RESET | AD9832_SLEEP |
> >                                       AD9832_CLR);
> >               else
> > -                     st->ctrl_src |= AD9832_RESET;
> > +                     st->ctrl_src |= AD9832_SLEEP;
> >
> >               st->data = cpu_to_be16((AD9832_CMD_SLEEPRESCLR << CMD_SHIFT) |
> >                                       st->ctrl_src);
>