Re: [PATCH 1/3] dt-bindings: clock: renesas: rcar-usb2-clock-sel: Fix clock[-name]s properties

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Shimoda-san,

On Fri, Oct 25, 2019 at 3:29 AM Yoshihiro Shimoda
<yoshihiro.shimoda.uh@renesas.com> wrote:
> > From: Geert Uytterhoeven, Sent: Thursday, October 24, 2019 8:46 PM
> > On Thu, Oct 24, 2019 at 1:17 PM Yoshihiro Shimoda
> > <yoshihiro.shimoda.uh@renesas.com> wrote:
> > > Since the hardware requires to enable both USB 2.0 host and peripheral
> > > functional clock, this patch fixes the documentation.
> > > Fortunately, no one has this device node for now, so that we don't
> > > need to think of backward compatibility.
> > >
> > > Fixes: 311accb64570 ("clk: renesas: rcar-usb2-clock-sel: Add R-Car USB 2.0 clock selector PHY")
> > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> >
> > Thanks four your patch!
> >
> > Looks good to me, so
> > Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
>
> Thank you for your review!
>
> > I'm just wondering about the inconsistent use of "_" and "-" in clock
> > names, but I don't have a better suggestion ("hs-usb-if", "usb_extal",
> > and "usb_xtal" do match the datasheet), so let's ignore my OCD ;-)
>
> I intended to match the names with the datasheet, but "ehci_ohci" doesn't match though...
> So, should I change the "ehci_ohci" to "ehci/ohci"?

I think that's up to you.  Both are fine to me.
Given this is USB2, using "ehci" only may be fine, too.

Note that
  - the only other clock with a slash in its name in the datasheet is
    "ths/thc", which we call "thermal" in the clock drivers,
  - the "ehci/ohci" clocks are called "ehciN" or "usb-ehci" in the clock
    drivers.
Nothing relies on those names, though, and they're not part of any ABI,
unlike the ehci/ohci clock input in this binding.

> > > --- a/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt
> > > +++ b/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel.txt
> > > @@ -38,7 +38,8 @@ Required properties:
> > >  - reg: offset and length of the USB 2.0 clock selector register block.
> > >  - clocks: A list of phandles and specifier pairs.
> > >  - clock-names: Name of the clocks.
> > > - - The functional clock must be "ehci_ohci"
> > > + - The functional clock of USB 2.0 host side must be "ehci_ohci"
> >
> > "_" means "and".
> >
> > > + - The functional clock of HS-USB side must be "hs-usb-if"
> >
> > "-" means concatenation of terms.
> >
> > >   - The USB_EXTAL clock pin must be "usb_extal"
> > >   - The USB_XTAL clock pin must be "usb_xtal"
> >
> > "_" means concatenation of terms.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds