Re: [PATCH v6 2/2] iio: adc: max14001: New driver

[Jonathan Cameron]

On Wed, 14 Jun 2023 14:53:12 +0300
Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote:

> On Wed, Jun 14, 2023 at 1:43 PM Paller, Kim Seer
> <KimSeer.Paller@xxxxxxxxxx> wrote:
> > > From: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> > > Sent: Wednesday, June 14, 2023 5:12 PM  
> 
> ...
> 
> > > > +               /* select external voltage reference source for the ADC */
> > > > +               ret = max14001_reg_update(st, MAX14001_CFG,
> > > > +                                         MAX14001_CFG_EXRF, 1);
> > > > +
> > > > +               ret = regulator_get_voltage(vref);
> > > > +               if (ret < 0)
> > > > +                       return dev_err_probe(dev, ret,
> > > > +                                            "Failed to get vref\n");  
> > >
> > > Is it important to choose the external reference source _before_ getting the
> > > voltage of the regulator? If not, I would swap these calls, otherwise the
> > > comment is needed to explain why the sequence is important in the way it's
> > > written.  
> >
> > It is not important. These calls can be swap without any issues.  
> 
> If you send a new version, please swap, otherwise I hope Jonathan can
> do it when applying.
> 

I made these changes whilst applying...

--- a/drivers/iio/adc/max14001.c
+++ b/drivers/iio/adc/max14001.c
@@ -290,16 +290,19 @@ static int max14001_probe(struct spi_device *spi)
                if (ret)
                        return ret;
 
-               /* select external voltage reference source for the ADC */
-               ret = max14001_reg_update(st, MAX14001_CFG,
-                                         MAX14001_CFG_EXRF, 1);
-
                ret = regulator_get_voltage(vref);
                if (ret < 0)
                        return dev_err_probe(dev, ret,
                                             "Failed to get vref\n");
 
                st->vref_mv = ret / 1000;
+
+               /* select external voltage reference source for the ADC */
+               ret = max14001_reg_update(st, MAX14001_CFG,
+                                         MAX14001_CFG_EXRF, 1);
+
+               if (ret < 0)
+                       return ret;
        }
 
        mutex_init(&st->lock);


Note that whilst I've applied this to the togreg branch of iio.git - it is just
a tiny bit too late to make the merge window that starts in about a week.
As such I'll only push this out as testing until I can rebase the tree
on rc1 once available.

Thanks,

Jonathan