Re: [PATCH RESEND 06/12] clk: sh: SH7750/51 PLL and divider clock driver

[Geert Uytterhoeven]

Hi Sato-san,

On Sun, May 1, 2016 at 7:08 AM, Yoshinori Sato
<ysato@xxxxxxxxxxxxxxxxxxxx> wrote:
> Signed-off-by: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
> ---
>  .../bindings/clock/renesas,sh-div-clock.txt        |  24 ++
>  .../bindings/clock/renesas,sh7750-div-clock.txt    |  27 ++
>  .../bindings/clock/renesas,sh7750-pll-clock.txt    |  26 ++
>  drivers/clk/Kconfig                                |   1 +
>  drivers/clk/Makefile                               |   3 +-
>  drivers/clk/sh/Kconfig                             |   5 +
>  drivers/clk/sh/Makefile                            |   2 +
>  drivers/clk/sh/clk-sh7750.c                        | 223 ++++++++++++++
>  drivers/clk/sh/clk-shdiv.c                         | 338 +++++++++++++++++++++
>  9 files changed, 648 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/clock/renesas,sh-div-clock.txt
>  create mode 100644 Documentation/devicetree/bindings/clock/renesas,sh7750-div-clock.txt
>  create mode 100644 Documentation/devicetree/bindings/clock/renesas,sh7750-pll-clock.txt
>  create mode 100644 drivers/clk/sh/Kconfig
>  create mode 100644 drivers/clk/sh/Makefile
>  create mode 100644 drivers/clk/sh/clk-sh7750.c
>  create mode 100644 drivers/clk/sh/clk-shdiv.c
>
> diff --git a/Documentation/devicetree/bindings/clock/renesas,sh-div-clock.txt b/Documentation/devicetree/bindings/clock/renesas,sh-div-clock.txt
> new file mode 100644
> index 0000000..399e0da
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/renesas,sh-div-clock.txt
> @@ -0,0 +1,24 @@
> +* Renesas H8/300 divider clock

[...]

h8300?

> diff --git a/Documentation/devicetree/bindings/clock/renesas,sh7750-div-clock.txt b/Documentation/devicetree/bindings/clock/renesas,sh7750-div-clock.txt
> new file mode 100644
> index 0000000..8c57ab5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/renesas,sh7750-div-clock.txt
> @@ -0,0 +1,27 @@
> +* Renesas SH7750/51 divider clock
> +
> +Required Properties:
> +
> +  - compatible: Must be "renesas,sh7750-div-clock"
> +
> +  - clocks: Reference to the parent clocks (mostly PLL)
> +
> +  - #clock-cells: Must be 0
> +
> +  - reg: Base address and length of the divide rate selector
> +
> +  - renesas,offset: bit offset of selector
> +
> +  - clock-output-names: The names of the clocks.
> +
> +Example
> +-------
> +
> +        iclk: iclk {
> +                compatible = "renesas,sh7750-div-clock";
> +                clocks = <&pllclk>;
> +                #clock-cells = <0>;
> +                reg = <0xffc00000 2>;
> +               renesas,offset = <6>;
> +               clock-output-names = "ick";
> +        };
> diff --git a/Documentation/devicetree/bindings/clock/renesas,sh7750-pll-clock.txt b/Documentation/devicetree/bindings/clock/renesas,sh7750-pll-clock.txt
> new file mode 100644
> index 0000000..06a3d31
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/renesas,sh7750-pll-clock.txt
> @@ -0,0 +1,26 @@
> +Renesas SH7750/51 PLL clock
> +
> +This device is Clock multiplyer
> +
> +Required Properties:
> +
> +  - compatible: Must be "renesas,sh7750-pll-clock"
> +
> +  - clocks: Reference to the parent clocks
> +
> +  - #clock-cells: Must be 0
> +
> +  - renesas,mult: PLL1 multiply rate
> +
> +  - reg: Two rate selector (FRQCR / WDT) register address
> +
> +Example
> +-------
> +
> +        pllclk: pllclk {
> +                compatible = "renesas,sh7750-pll-clock";
> +                clocks = <&oclk>;
> +                #clock-cells = <0>;
> +               renesas,mult = <12>;
> +                reg = <0xffc00000 2>, <0xffc00008 4>;
> +        };

As the registers of the PLL clock and the various div clocks are the
same, I think it will be simpler to just write a single driver that provides
all clocks, instead of describing all clocks in DT.

Cfr. drivers/clk/renesas/*-cpg-mssr.c vs. drivers/clk/renesas/clk-rcar-gen2.c
+ drivers/clk/renesas/clk-mstp.c + drivers/clk/renesas/clk-div6.c.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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