Re: [PATCH v3 2/3] regulator: dt-bindings: Add mps,mpq2286 power-management IC

[Saravanan Sekar]

On 08/10/23 19:22, Guenter Roeck wrote:
> On Sun, Oct 08, 2023 at 12:40:29PM +0200, Krzysztof Kozlowski wrote:
> > On 08/10/2023 03:20, Guenter Roeck wrote:
> > > On Sat, Oct 07, 2023 at 10:28:02PM +0530, Saravanan Sekar wrote:
> > > > Document mpq2286 power-management IC. Instead of simple 'buck', 'buck0' is
> > > > used to keep the driver common which handles multiple regulators.
> > >
> > > Sorry for the maybe dumb question, but where can I find the driver
> > > depencency on buck naming ?
> >
> > I guess it is because:
> > PMBUS_REGULATOR_STEP("buck", 0, MPQ7932_N_VOLTAGES,
> > creates regulator name as buck+id (so buck0).
>
> Ah, good point. Problem here is that this is already kind of common,
> even though the use of "buckX" isn't. Look for "vout0", or
> 'PMBUS_REGULATOR("vout", 0)'. Apparently so far no one took offence
> if a regulator was named "vout0" even if "vout1" didn't exist.
>
> I don't really have a good solution right now, but I guess we'll need
> a second set of macros for the single-regulator case, or maybe generate
> struct regulator_desc arrays using a function. I'll have to explore
> options.
>
> Please let me know how you want the subsystem to handle existing
> single-channel regulators with numbered regulator name.
>
> Saravanan - for this driver please just declare a local driver-specific
> variant of the PMBUS_REGULATOR_STEP() macro which doesn't use indexing,
> use it to initialise a second regulators_desc array, and use that second
> array for mpq2286. That is a bit messy, but acceptable for now until
> there is a more generic solution (unless of course you have an idea for
> one and want to implement it, but that is not a requirement).
Hello Guenter,

Thanks for your proposal as intermediate fix local declaration of macro, 
could you please suggest whether below changes is acceptable as workaround?

+++ b/drivers/hwmon/pmbus/mpq7932.c
@@ -118,6 +118,12 @@ static int mpq7932_probe(struct i2c_client *client)
 #if IS_ENABLED(CONFIG_SENSORS_MPQ7932_REGULATOR)
        info->num_regulators = info->pages;
        info->reg_desc = mpq7932_regulators_desc;
+
+       if (info->num_regulators == 1) {
+               mpq7932_regulators_desc->name = "buck";
+               mpq7932_regulators_desc->of_match = of_match_ptr("buck");
+       }
+


> Thanks,
> Guenter

Thanks,
Saravanan