Re: [PATCH v3 2/3] staging: iio: ad9832: Refactor powerdown control

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 24 Apr 2025 18:25:51 -0400
Gabriel Shahrouzi <gshahrouzi@gmail.com> wrote:

> On Mon, Apr 21, 2025 at 7:37 AM Jonathan Cameron <jic23@kernel.org> wrote:
> >
> > On Sun, 20 Apr 2025 13:54:18 -0400
> > Gabriel Shahrouzi <gshahrouzi@gmail.com> wrote:
> >  
> > > Replace custom implementation with out_altvoltage_powerdown ABI. The
> > > attribute's logic is inverted (1 now enables powerdown) to match the
> > > standard. Modernize driver by using the standard IIO interface.
> > >
> > > Signed-off-by: Gabriel Shahrouzi <gshahrouzi@gmail.com>
> > > ---
> > >  drivers/staging/iio/frequency/ad9832.c | 44 ++++++++++++++++++--------
> > >  1 file changed, 30 insertions(+), 14 deletions(-)
> > >
> > > diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
> > > index 0872ff4ec4896..a8fc20379efed 100644
> > > --- a/drivers/staging/iio/frequency/ad9832.c
> > > +++ b/drivers/staging/iio/frequency/ad9832.c
> > > @@ -167,6 +167,34 @@ static int ad9832_write_phase(struct ad9832_state *st,
> > >       return spi_sync(st->spi, &st->phase_msg);
> > >  }
> > >
> > > +static ssize_t ad9832_write_powerdown(struct device *dev, struct device_attribute *attr,
> > > +                                   const char *buf, size_t len)
> > > +{
> > > +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> > > +     struct ad9832_state *st = iio_priv(indio_dev);
> > > +     int ret;
> > > +     unsigned long val;
> > > +
> > > +     ret = kstrtoul(buf, 10, &val);
> > > +     if (ret)
> > > +             goto error_ret;
> > > +
> > > +     mutex_lock(&st->lock);  
> >
> > Look at how guard(mutex)(&st->lock);
> > can be used in this driver to simplify things considerably.  
> Noted, added into new version.
> > May make sense to do that before introducing this new code.  
> Not sure whether to have made it its own patch or not. I grouped it
> together with the new code since it also uses locking.
For new code it is fine to do it at the same time.

If there are other places it makes sense in the driver, separate
patch covering all those.

Jonathan