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

[Dragan Simic]

Hello all,

On 2024-04-15 13:11, Robert Marko wrote:
> 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.

FWIW, ifdef'ing the code out seems like a cleaner approach to me.

>> > 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)