Re: [RFC 4/4] arm64: dts: r8a7795: Add Z clock scaling support

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Khiem Nguyen <khiem.nguyen.xt@rvc.renesas.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>,
	Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@codeaurora.org>,
	Simon Horman <horms+renesas@verge.net.au>,
	Magnus Damm <damm+renesas@opensource.se>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	"linux-clk@vger.kernel.org" <linux-clk@vger.kernel.org>,
	"linux-renesas-soc@vger.kernel.org"
	<linux-renesas-soc@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	Toru Oishi <toru.oishi.zj@rvc.renesas.com>,
	Linux PM list <linux-pm@vger.kernel.org>
Subject: Re: [RFC 4/4] arm64: dts: r8a7795: Add Z clock scaling support
Date: Tue, 17 May 2016 15:03:23 +0200	[thread overview]
Message-ID: <CAMuHMdW52t9SZq89QjdB=P-aM8dCSq-YYLCxRA7Wk1NVGLsUPg@mail.gmail.com> (raw)
In-Reply-To: <5731678E.3080003@rvc.renesas.com>

On Tue, May 10, 2016 at 6:46 AM, Khiem Nguyen
<khiem.nguyen.xt@rvc.renesas.com> wrote:
> This patch adds Z clock scaling support for CA57 in R8A7795 SoC.
> An OPP table is created with the supported frequency scaling.
>
> Signed-off-by: Dien Pham <dien.pham.ry@rvc.renesas.com>
> Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
> Signed-off-by: Khiem Nguyen <khiem.nguyen.xt@rvc.renesas.com>
> ---
>  arch/arm64/boot/dts/renesas/r8a7795.dtsi | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/renesas/r8a7795.dtsi
> b/arch/arm64/boot/dts/renesas/r8a7795.dtsi
> index 7181db0..041d0f2 100644
> --- a/arch/arm64/boot/dts/renesas/r8a7795.dtsi
> +++ b/arch/arm64/boot/dts/renesas/r8a7795.dtsi
> @@ -43,6 +43,8 @@
>                         power-domains = <&sysc R8A7795_PD_CA57_CPU0>;
>                         next-level-cache = <&L2_CA57>;
>                         enable-method = "psci";
> +                       clocks =<&cpg CPG_CORE R8A7795_CLK_Z>;
> +                       operating-points-v2 = <&cluster0_opp_tb0>;
>                 };
>
>                 a57_1: cpu@1 {
> @@ -52,6 +54,7 @@
>                         power-domains = <&sysc R8A7795_PD_CA57_CPU1>;
>                         next-level-cache = <&L2_CA57>;
>                         enable-method = "psci";
> +                       operating-points-v2 = <&cluster0_opp_tb0>;
>                 };
>                 a57_2: cpu@2 {
>                         compatible = "arm,cortex-a57","arm,armv8";
> @@ -60,6 +63,7 @@
>                         power-domains = <&sysc R8A7795_PD_CA57_CPU2>;
>                         next-level-cache = <&L2_CA57>;
>                         enable-method = "psci";
> +                       operating-points-v2 = <&cluster0_opp_tb0>;
>                 };
>                 a57_3: cpu@3 {
>                         compatible = "arm,cortex-a57","arm,armv8";
> @@ -68,6 +72,28 @@
>                         power-domains = <&sysc R8A7795_PD_CA57_CPU3>;
>                         next-level-cache = <&L2_CA57>;
>                         enable-method = "psci";
> +                       operating-points-v2 = <&cluster0_opp_tb0>;
> +               };
> +       };
> +
> +       cluster0_opp_tb0: opp_table0 {
> +               compatible = "operating-points-v2";
> +               opp-shared;
> +
> +               opp@500000000 {
> +                       opp-hz = /bits/ 64 <500000000>;
> +                       opp-microvolt = <820000>;
> +                       clock-latency-ns = <300000>;
> +               };
> +               opp@1000000000 {
> +                       opp-hz = /bits/ 64 <1000000000>;
> +                       opp-microvolt = <820000>;
> +                       clock-latency-ns = <300000>;
> +               };
> +               opp@1500000000 {
> +                       opp-hz = /bits/ 64 <1500000000>;
> +                       opp-microvolt = <820000>;
> +                       clock-latency-ns = <300000>;

With W=1:

Warning (unit_address_vs_reg): Node /opp_table0/opp@500000000 has a
unit name, but no reg property
Warning (unit_address_vs_reg): Node /opp_table0/opp@1000000000 has a
unit name, but no reg property
Warning (unit_address_vs_reg): Node /opp_table0/opp@1500000000 has a
unit name, but no reg property

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