[PATCH] usb: dwc3-generic: fix support without DM_REGULATOR

[Robert Marko]

On Mon, Apr 15, 2024 at 12:57 PM Caleb Connolly
<caleb.connolly at linaro.org> wrote:
>
>
>
> On 15/04/2024 11:53, Robert Marko wrote:
> > Recent addition of vbus-supply support has broke platform which dont use
> > controllable regulators for USB.
> >
> > Issue is that even withou DM_REGULATOR being enabled regulator related
> > functions will still build as there is a stub in regulator.h but they will
> > simply return -ENOSYS which will then make dwc3_generic_host_probe()
> > return the same error thus breaking probe.
>
> Rather than stubbing out the code, could you check for -ENOSYS and
> ignore the error in that case? I believe there's only one place where
> this matters (marked below).

Sure, that was my first approach but it did not seem right to me.
But if its OK with you, I can do that.

Regards,
Robert

> >
> > Fixes: de451d5d5b6f ("usb: dwc3-generic: support external vbus regulator")
> > Signed-off-by: Robert Marko <robert.marko at sartura.hr>
> > ---
> >  drivers/usb/dwc3/dwc3-generic.c | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
> > index 7a00529a2a..784d3ec2ed 100644
> > --- a/drivers/usb/dwc3/dwc3-generic.c
> > +++ b/drivers/usb/dwc3/dwc3-generic.c
> > @@ -242,6 +242,7 @@ static int dwc3_generic_host_probe(struct udevice *dev)
> >       if (rc)
> >               return rc;
> >
> > +#if CONFIG_IS_ENABLED(DM_REGULATOR)
> >       rc = device_get_supply_regulator(dev, "vbus-supply", &priv->vbus_supply);
> >       if (rc)
> >               debug("%s: No vbus regulator found: %d\n", dev->name, rc);
> > @@ -250,14 +251,17 @@ static int dwc3_generic_host_probe(struct udevice *dev)
> >       rc = regulator_set_enable_if_allowed(priv->vbus_supply, true);
> >       if (rc)
> >               return rc;
>
> Here, if (rc && rc != -ENOSYS)
> or even if (CONFIG_IS_ENABLED(DM_REGULATOR) && rc) to be verbose (maybe
> not the preferred style though).
>
> All the other regulator_* calls either ignore the result or only print a
> debug message.
> > +#endif
> >
> >       hccr = (struct xhci_hccr *)priv->gen_priv.base;
> >       hcor = (struct xhci_hcor *)(priv->gen_priv.base +
> >                       HC_LENGTH(xhci_readl(&(hccr)->cr_capbase)));
> >
> >       rc = xhci_register(dev, hccr, hcor);
> > +#if CONFIG_IS_ENABLED(DM_REGULATOR)
> >       if (rc)
> >               regulator_set_enable_if_allowed(priv->vbus_supply, false);
> > +#endif
> >
> >       return rc;
> >  }
> > @@ -265,14 +269,18 @@ static int dwc3_generic_host_probe(struct udevice *dev)
> >  static int dwc3_generic_host_remove(struct udevice *dev)
> >  {
> >       struct dwc3_generic_host_priv *priv = dev_get_priv(dev);
> > +#if CONFIG_IS_ENABLED(DM_REGULATOR)
> >       int rc;
> > +#endif
> >
> >       /* This function always returns 0 */
> >       xhci_deregister(dev);
> >
> > +#if CONFIG_IS_ENABLED(DM_REGULATOR)
> >       rc = regulator_set_enable_if_allowed(priv->vbus_supply, false);
> >       if (rc)
> >               debug("%s: Failed to disable vbus regulator: %d\n", dev->name, rc);
> > +#endif
> >
> >       return dwc3_generic_remove(dev, &priv->gen_priv);
> >  }
>
> --
> // Caleb (they/them)



-- 
Robert Marko
Staff Embedded Linux Engineer
Sartura Ltd.
Lendavska ulica 16a
10000 Zagreb, Croatia
Email: robert.marko at sartura.hr
Web: www.sartura.hr