Re: [PATCH v1 2/2] iio: dac: ad5504: use adi,output-range-volts for scale calculation

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 12 Feb 2026 22:15:55 +0200
Andy Shevchenko <andriy.shevchenko@intel.com> wrote:

> On Thu, Feb 12, 2026 at 07:19:55PM +0100, Taha Ed-Dafili wrote:
> > The driver previously used VCC to calculate the scale, but the datasheet
> > states the output range is fixed by the R_SEL pin (0-30V or 0-60V).
> > 
> > Update probe to read `adi,output-range-volts` for the scale. Default
> > to the 60V range if the property is missing, while keeping the VCC
> > regulator enable for power.  
> 
> ...
> 
> >  #include <linux/regulator/consumer.h>
> >  #include <linux/module.h>
> >  #include <linux/bitops.h>
> > +#include <linux/property.h>  
> 
> Add it before 'linux/s*.h' includes to make less ordering issues.
> Ideally one additional patch to sort the headers and one to replace
> "proxy" headers (following IWYU principle).
> 
> ...
> 
> > +	ret = device_property_read_u32(&spi->dev, "adi,output-range-volts", &val);  
> 
> You can pack this into 80 limit with help of
> 
> 	struct device *dev = &spi->dev;
> 
> being defined in the top of the function.
> 
> > +	if (ret)
> > +		val = 60;  
> 
> Also this seems an optional, so
> 
> 	val = 60;
> 	device_property_read_u32(dev, "adi,output-range-volts", &val);
> 
> would be enough.
> 
> ...
> 
> > +	if (val == 60)
> > +		st->vref_mv = 60000;  
> 
> 60 * MILLI;

val * MILLI
given it only takes the values 30 and 60 I think. If you want to protect
against other values, then check it explicitly rather than everything than
isn't 60 being assumed to be 30.

Thanks,

J


> 
> > +	else
> > +		st->vref_mv = 30000;  
> 
> 30 * MILLI;
> 
> Needs units.h.
>