RE: [PATCH v3 1/2] dt-bindings: clock: renesas,r9a06g032-sysctrl: Document power Domains

[Phil Edworthy]

Hi Geert,

On 28 May 2019 08:29 Geert Uytterhoeven wrote:
> On Fri, May 24, 2019 at 5:32 PM Gareth Williams wrote:
> > The driver is gaining power domain support, so add the new property to
> > the DT binding and update the examples.
> >
> > Signed-off-by: Gareth Williams <gareth.williams.jx@xxxxxxxxxxx>
> 
> Thanks for your patch!
> 
> > ---
> > a/Documentation/devicetree/bindings/clock/renesas,r9a06g032-sysctrl.tx
> > t
> > +++ b/Documentation/devicetree/bindings/clock/renesas,r9a06g032-
> sysctr
> > +++ l.txt
> @@ -40,4 +42,5 @@ Examples
> >                 reg-io-width = <4>;
> >                 clocks = <&sysctrl R9A06G032_CLK_UART0>;
> >                 clock-names = "baudclk";
> > +               power-domains = <&sysctrl>;
> 
> This is an interesting example: according to the driver,
> R9A06G032_CLK_UART0, is not clock used for power management?
> 
> Oh, the real uart0 node in arch/arm/boot/dts/r9a06g032.dtsi uses
> 
>     clocks = <&sysctrl R9A06G032_CLK_UART0>, <&sysctrl
> R9A06G032_HCLK_UART0>;
>     clock-names = "baudclk", "apb_pclk";
> 
> That does make sense...
Note that the Synopsys DW uart driver already gets the "apb_pclk" clock, so
we donât actually need to use clock domains to enable this clock.

This is also true for many of the peripheral drivers used on rzn1 (Synopsys
gpio controller, i2c controller, gmac, dmac, Arasan sdio controller). The
commit to add this clock to the i2c controller driver is my fault, as I was
following the pattern of the others.

Of the few drivers that don't already get the hclk/pclk used to access the
peripherals is the Synopsys spi controller (though that currently doesnât
support runtime PM) and the USB Host controller.

BR
Phil
 
> With the above fixed:
> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> 
> 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