Re: [PATCH v3 4/6] usb: dwc3: Add Amlogic A1 DWC3 glue

[Martin Blumenstingl <martin.blumenstingl@googlemail.com>]

Hello Hanjie,

On Thu, Jan 2, 2020 at 1:30 AM Hanjie Lin <hanjie.lin@amlogic.com> wrote:
[...]
> >> -               if (i == USB2_OTG_PHY) {
> >> +               if (priv->soc_id == MESON_SOC_G12A && i == USB2_OTG_PHY) {
> > on GXL we have two PHYs (0 and 1), the second one is OTG capable
> > on GXM we have three PHYs (0..2), the second one is OTG capable
> > on G12A/G12B we have two PHYs (0 and 1), the second one is OTG capable
> >
> > you already wrote that there is only one USB2 PHY on the A1 SoC
> > is really only the second PHY port ("usb2-phy1" instead of
> > "usb2-phy0") used on A1?
> > if "usb2-phy0" is correct then you don't need these checks (there are
> > more checks like this below)
>
> Actually, A1 have same phys("usb2-phy0", "usb2-phy1", "usb3-phy0") and register base with G12A.
> But A1 driver is designed to support host mode with usb2-phy1 only.
OK, thank you for clarifying this interesting decision made by the HW team

...]
> >> -       usb_role_switch_unregister(priv->role_switch);
> >> +       if (priv->soc_id == MESON_SOC_G12A)
> >> +               usb_role_switch_unregister(priv->role_switch);
> > I didn't expect this because in _probe usb_role_switch_register is still called
> > on A1 we now call usb_role_switch_register() but we never call
> > usb_role_switch_unregister()
> >
>
> Actually, usb_role_switch_register() can be called only in G12A.
>
> dwc3_meson_g12a_probe()
>          ...
>          if (priv->soc_id != MESON_SOC_G12A)
>                  goto setup_pm_runtime;
I completely missed that, thank you for clarifying it

>
> Same with second suggestion, this different SoC extra logic could avoided by add constraints
> to .yaml.
> I will do this in next version.
that would be awesome if it works out!


Martin