Re: [PATCH v8 16/17] PCI/pwrctl: add a PCI power control driver for power sequenced devices

Dmitry Baryshkov
2024-06-04T23:35:05Z

On Wed, 5 Jun 2024 at 02:23, Bjorn Helgaas <helgaas@kernel.org> wrote:
>
> On Tue, May 28, 2024 at 09:03:24PM +0200, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> >
> > Add a PCI power control driver that's capable of correctly powering up
> > devices using the power sequencing subsystem. The first users of this
> > driver are the ath11k module on QCA6390 and ath12k on WCN7850.
>
> Can you add a little detail here about what benefit we will see from
> this driver? E.g., something that doesn't work correctly now, but
> will work with this driver?
>
> > +static const struct of_device_id pci_pwrctl_pwrseq_of_match[] = {
> > + {
> > + /* ATH11K in QCA6390 package. */
> > + .compatible = "pci17cb,1101",
> > + .data = "wlan",
> > + },
> > + {
> > + /* ATH12K in WCN7850 package. */
> > + .compatible = "pci17cb,1107",
> > + .data = "wlan",
> > + },
>
> IIUC, "pci17cb,1101" and "pci17cb,1107" exist partly so we can check
> that a DTS conforms to the schema, e.g., a "pci17cb,1101" node
> contains all the required regulators. For that use, we obviously need
> a very specific "compatible" string.
>
> Is there any opportunity to add a more generic "compatible" string in
> addition to those so this list doesn't have to be updated for every
> PMU? The .data here is "wlan" in both cases, and for this purpose, we
> don't care whether it's "pci17cb,1101" or "pci17cb,1107".

These two devices have different set of regulators and different
requirements to power them on.

--
With best wishes
Dmitry