[PATCH/RFC] serial: sh-sci: Add device tree support for r8a7779

[Simon Horman]

On Fri, Apr 25, 2014 at 09:11:06AM +0200, Geert Uytterhoeven wrote:
> On Fri, Apr 25, 2014 at 9:05 AM, Laurent Pinchart
> <laurent.pinchart at ideasonboard.com> wrote:
> >> +     scif0: serial at ffe40000 {
> >> +             compatible = "renesas,scif", "renesas,scif-r8a7779";
> >> +             reg = <0xffe40000 265>;
> >> +             interrupt-parent = <&gic>;
> >> +             interrupts = <0 88 IRQ_TYPE_LEVEL_HIGH>;
> >> +             clocks = <&cpg_clocks R8A7779_CLK_P>;
> >> +             clock-names = "sci_ick";
> >
> > Clock handling in the sh-sci driver should probably be improved. The driver
> > currently requires an "sci_ick" interface clock and supports an optional
> > "sci_fck" functional clock. In practice, as far as I can see, platforms that
> > provide both sci_ick and sci_fck set the two clocks to the same source.
> 
> That's right. As a consequence, the clock's enable count is incremented
> 3 times:
>   - once for fck,
>   - once for ick,
>   - once for generic Runtime PM using the "NULL" clock.

This approach is fine by me.
But I think you need to maintain compatibility with the old
binding ("sci_ick" required, "sci_fsk") as it seems that
was included in v3.14.

> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 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
>