Re: [PATCH v3 02/12] dt-bindings: clock: r9a08g045-vbattb: Add clock IDs for the VBATTB controller

Geert Uytterhoeven
2024-10-10T09:56:05Z

Hi Claudiu,

Thanks for your patch!

On Fri, Aug 30, 2024 at 3:02 PM Claudiu <claudiu.beznea@tuxon.dev> wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
>
> The VBATTB controllers controls the clock for the RTC on the Renesas

controller

> RZ/G3S. The HW block diagram for the clock logic is as follows:
>
> +----------+ XC `\
> RTXIN --->| |----->| \ +----+ VBATTCLK
> | 32K clock| | |----->|gate|----------->
> | osc | XBYP | | +----+
> RTXOUT --->| |----->| /
> +----------+ ,/
>
> One could connect as input to this HW block either a crystal oscillator or

Please drop "oscillator". An external crystal is used with the internal
crystal oscillator.

> an external clock device.
>
> After discussions w/ Stephen Boyd the clock tree associated with this
> hardware block was exported in Linux as:
>
> input-xtal
> xbyp
> xc
> mux
> vbattclk
>
> where:
> - input-xtal is the input clock (connected to RTXIN, RTXOUT pins)
> - xc, xbyp are mux inputs
> - mux is the internal mux
> - vbattclk is the gate clock that feeds in the end the RTC
>
> to allow selecting the input of the MUX though assigned-clock DT
> properties, using the already existing clock drivers and avoid adding
> other DT properties.
>
> This allows select the input of the mux based on the type of the
> connected input clock:
> - if the 32768 crystal oscillator is connected as input for the VBATTB,

Please drop "oscillator".

> the input of the mux should be xc
> - if an external clock device is connected as input for the VBATTB the
> input of the mux should be xbyp
>
> Add clock IDs for the VBATTB controller.
>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> ---
>
> Changes in v3:
> - none; this patch is new

> --- /dev/null
> +++ b/include/dt-bindings/clock/r9a08g045-vbattb.h

renesas,r9a08g045-vbattb.h

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