On Fri, Jan 2, 2026 at 4:10 PM Dmitry Baryshkov
<[email protected]> wrote:
>
> On Fri, 2 Jan 2026 at 13:07, Bartosz Golaszewski <[email protected]> wrote:
> >
> > On Wed, Dec 31, 2025 at 12:36 AM Dmitry Baryshkov
> > <[email protected]> wrote:
> > >
> > > The WCN39xx family of WiFi/BT chips incorporates a simple PMU, spreading
> > > voltages over internal rails. Implement support for using powersequencer
> > > for this family of ATH10k devices in addition to using regulators.
> > >
> > > Signed-off-by: Dmitry Baryshkov <[email protected]>
> > > ---
> >
> > [snip]
> >
> > >
> > > static void ath10k_snoc_wlan_disable(struct ath10k *ar)
> > > @@ -1762,7 +1779,27 @@ static int ath10k_snoc_probe(struct
> > > platform_device *pdev)
> > > goto err_release_resource;
> > > }
> > >
> > > - ar_snoc->num_vregs = ARRAY_SIZE(ath10k_regulators);
> > > + /*
> > > + * Backwards compatibility, ignore the defer error from pwrseq,
> > > if it
> > > + * should be used, we will get an error from regulator get.
> > > + */
> >
> > Can you elaborate on this? I'm not exactly following. I suppose you
> > mean the regulator_get() will return -EPROBE_DEFER? One of the
> > supplies exposed by the PMU?
>
> Yes. devm_pwrseq_get() can return -EPROBE_DEFER in two cases:
> - it is not supposed to be used
> - it is supposed to be used, but the driver hasn't probed yet.
>
Yes but normally driver core would still create a devlink between the
device binding to the PMU node and the consumer of its regulators -
this device - so we can expect that it will always be the first one,
no? Unless we need this driver to be firmware-agnostic.
> There is no simple way to distinguish between these two cases, but:
> - if it is not supposed to be used, then regulator_bulk_get() will
> return all regulators as expected, continuing the probe
> - if it is supposed to be used, but wasn't probed yet, we will get
> -EPROBE_DEFER from regulator_bulk_get() too.
>
> I can write that in a comment, if you think that it makes the code more
> obvious.
>
Yes, please make it more descriptive. Ideally I'd like to improve the
API to avoid such confusion in the future.
Bartosz
> >
> > Bart
> >
> > > + ar_snoc->pwrseq = devm_pwrseq_get(&pdev->dev, "wlan");
> > > + if (IS_ERR(ar_snoc->pwrseq)) {
> > > + ret = PTR_ERR(ar_snoc->pwrseq);
> > > + ar_snoc->pwrseq = NULL;
> > > + if (ret != -EPROBE_DEFER)
> > > + goto err_free_irq;
> > > +
> > > + ar_snoc->num_vregs = ARRAY_SIZE(ath10k_regulators);
> > > + } else {
> > > + /*
> > > + * The first regulator (vdd-0.8-cx-mx) is used to power
> > > on part
> > > + * of the SoC rather than the PMU on WCN399x, the rest are
> > > + * handled via pwrseq.
> > > + */
> > > + ar_snoc->num_vregs = 1;
> > > + }
> > > +
>
>
>
> --
> With best wishes
> Dmitry
