Re: [PATCH v3 1/2] iio:adc:ad7476: Handle the different regulators used by various parts.

[Jonathan Cameron <jic23@kernel.org>]

On Sun, 25 Apr 2021 16:18:02 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> On Sat, 24 Apr 2021 20:20:41 +0200
> Lars-Peter Clausen <lars@metafoo.de> wrote:
> 
> > On 4/24/21 7:03 PM, Jonathan Cameron wrote:  
> > > [...]
> > >   
> > > +	/* Either vcc or vref (below) as appropriate */
> > > +	if (!st->chip_info->int_vref_uv)
> > > +		st->ref_reg = reg;
> > > +
> > > +	if (st->chip_info->has_vref) {
> > > +
> > > +		/* If a device has an internal reference vref is optional */
> > > +		if (st->chip_info->int_vref_uv) {
> > > +			reg = devm_regulator_get_optional(&spi->dev, "vref");
> > > +		} else {
> > > +			reg = devm_regulator_get(&spi->dev, "vref");
> > > +			if (IS_ERR(reg))
> > > +				return PTR_ERR(reg);
> > > +		}
> > > +
> > > +		if (!IS_ERR(reg)) {
> > > +			ret = regulator_enable(reg);
> > > +			if (ret)
> > > +				return ret;
> > > +
> > > +			ret = devm_add_action_or_reset(&spi->dev,
> > > +						       ad7476_reg_disable,
> > > +						       reg);
> > > +			if (ret)
> > > +				return ret;
> > > +			st->ref_reg = reg;
> > > +		} else {    
> > We still need to check for errors, e.g. to support EPROBE_DEFER. The 
> > only error that can be ignored is ENOENT, which means no regulator is 
> > specified.  
> Good point.  I got fixated on all the different combinations and forgot the
> simple 'error' case :)

As far as I can tell -ENODEV is the return for no regulator specified.

Jonathan

> 
> V4 coming up.
> 
> Jonathan
> 
> > > +			/*
> > > +			 * Can only get here if device supports both internal
> > > +			 * and external reference, but the regulator connected
> > > +			 * to the external reference is not connected.
> > > +			 * Set the reference regulator pointer to NULL to
> > > +			 * indicate this.
> > > +			 */
> > > +			st->ref_reg = NULL;
> > > +		}
> > > +	}    
> >   
>