Re: [PATCH 4/8] dt-bindings: devfreq: add DMC device description

[Krzysztof Kozlowski <krzk@kernel.org>]

On Mon, 28 Jan 2019 at 20:21, Lukasz Luba <l.luba@partner.samsung.com> wrote:
>
> The patch adds description for DT binding for a new Exynos5 Dynamic Memory
> Controller device.
> It also contains needed MAINTAINERS file updates.
>
> CC: MyungJoo Ham <myungjoo.ham@samsung.com>
> CC: Kyungmin Park <kyungmin.park@samsung.com>
> CC: Chanwoo Choi <cw00.choi@samsung.com>
> CC: Rob Herring <robh+dt@kernel.org>
> CC: Mark Rutland <mark.rutland@arm.com>
> CC: Kukjin Kim <kgene@kernel.org>
> CC: Krzysztof Kozlowski <krzk@kernel.org>
> CC: linux-pm@vger.kernel.org
> CC: linux-samsung-soc@vger.kernel.org
> CC: devicetree@vger.kernel.org
> CC: linux-arm-kernel@lists.infradead.org
> CC: linux-kernel@vger.kernel.org
> Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
> ---
>  .../devicetree/bindings/devfreq/exynos5-dmc.txt    | 108 +++++++++++++++++++++
>  MAINTAINERS                                        |   7 ++
>  2 files changed, 115 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/devfreq/exynos5-dmc.txt
>
> diff --git a/Documentation/devicetree/bindings/devfreq/exynos5-dmc.txt b/Documentation/devicetree/bindings/devfreq/exynos5-dmc.txt
> new file mode 100644
> index 0000000..914bd85
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/devfreq/exynos5-dmc.txt
> @@ -0,0 +1,108 @@
> +* Exynos5 frequency and voltage scaling for Dynamic Memory Controller device
> +
> +The Samsung Exynos5 SoC has DMC (Dynamic Memory Controller) to which the DRAM
> +memory chips are connected. The driver is to monitor the controller in runtime
> +and switch frequency and voltage. To monitor the usage of the controller in
> +runtime, the driver uses the PPMU (Platform Performance Monitoring Unit), which
> +is able to measure the current load of the memory.
> +When 'userspace' governor is used for the driver, an application is able to
> +switch the DMC frequency.
> +
> +Required properties for DMC device for Exynos5422:
> +- compatible: Should be "samsung,exynos5422-bus".
> +- clock-names : the name of clock used by the bus, "bus".
> +- clocks : phandles for clock specified in "clock-names" property.
> +- devfreq-events : phandles for PPMU devices connected to this DMC.
> +
> +The example definition of a DMC and PPMU devices declared in DT is shown below:
> +
> +       ppmu_dmc0_0: ppmu_dmc0_0@10d00000 {
> +               compatible = "samsung,exynos-ppmu";
> +               reg = <0x10d00000 0x2000>;
> +               clocks = <&clock CLK_PCLK_PPMU_DREX0_0>;
> +               clock-names = "ppmu";
> +               status = "okay";
> +               events {
> +                       ppmu_event_dmc0_0: ppmu-event3-dmc0_0 {
> +                               event-name = "ppmu-event3-dmc0_0";
> +                       };
> +               };
> +       };
> +
> +
> +       ppmu_dmc0_1: ppmu_dmc0_1@10d10000 {
> +               compatible = "samsung,exynos-ppmu";
> +               reg = <0x10d10000 0x2000>;
> +               clocks = <&clock CLK_PCLK_PPMU_DREX0_1>;
> +               clock-names = "ppmu";
> +               status = "okay";
> +               events {
> +                       ppmu_event_dmc0_1: ppmu-event3-dmc0_1 {
> +                               event-name = "ppmu-event3-dmc0_1";
> +                       };
> +               };
> +       };
> +
> +       ppmu_dmc1_0: ppmu_dmc1_0@10d10000 {
> +               compatible = "samsung,exynos-ppmu";
> +               reg = <0x10d60000 0x2000>;
> +               clocks = <&clock CLK_PCLK_PPMU_DREX1_0>;
> +               clock-names = "ppmu";
> +               status = "okay";
> +               events {
> +                       ppmu_event_dmc1_0: ppmu-event3-dmc1_0 {
> +                               event-name = "ppmu-event3-dmc1_0";
> +                       };
> +               };
> +       };
> +
> +       ppmu_dmc1_1: ppmu_dmc1_1@10d70000 {
> +               compatible = "samsung,exynos-ppmu";
> +               reg = <0x10d70000 0x2000>;
> +               clocks = <&clock CLK_PCLK_PPMU_DREX1_1>;
> +               clock-names = "ppmu";
> +               status = "okay";
> +               events {
> +                       ppmu_event_dmc1_1: ppmu-event3-dmc1_1 {
> +                               event-name = "ppmu-event3-dmc1_1";
> +                       };
> +               };
> +       };
> +
> +       dmc: dmc@10c20000 {
> +               compatible = "samsung,exynos5422-dmc";
> +               reg = <0x10c20000 0x10000>, <0x10c30000 0x10000>,
> +                       <0x10030000 0x1000>, <0x10000000 0x1000>;
> +               clocks =        <&clock CLK_FOUT_SPLL>,
> +                               <&clock CLK_MOUT_SCLK_SPLL>,
> +                               <&clock CLK_FF_DOUT_SPLL2>,
> +                               <&clock CLK_FOUT_BPLL>,
> +                               <&clock CLK_MOUT_BPLL>,
> +                               <&clock CLK_SCLK_BPLL>,
> +                               <&clock CLK_MOUT_MX_MSPLL_CCORE>,
> +                               <&clock CLK_MOUT_MX_MSPLL_CCORE_PHY>,
> +                               <&clock CLK_MOUT_MCLK_CDREX>,
> +                               <&clock CLK_DOUT_CLK2X_PHY0>,
> +                               <&clock CLK_CLKM_PHY0>,
> +                               <&clock CLK_CLKM_PHY1>
> +                       ;

Join with previous line.

> +               clock-names =   "fout_spll",
> +                               "mout_sclk_spll",
> +                               "ff_dout_spll2",
> +                               "fout_bpll",
> +                               "mout_bpll",
> +                               "sclk_bpll",
> +                               "mout_mx_mspll_ccore",
> +                               "mout_mx_mspll_ccore_phy",
> +                               "mout_mclk_cdrex",
> +                               "dout_clk2x_phy0",
> +                               "clkm_phy0",
> +                               "clkm_phy1"
> +                               ;

Ditto.

> +
> +               status = "okay";
> +               devfreq-events = <&ppmu_dmc0_0>, <&ppmu_dmc0_1>,
> +                               <&ppmu_dmc1_0>, <&ppmu_dmc1_1>;
> +       };
> +
> +
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 9f64f8d..3581807 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3310,6 +3310,13 @@ S:       Maintained
>  F:     drivers/devfreq/exynos-bus.c
>  F:     Documentation/devicetree/bindings/devfreq/exynos-bus.txt
>
> +DMC FREQUENCY DRIVER FOR SAMSUNG EXYNOS5
> +M:     Lukasz Luba <l.luba@partner.samsung.com>
> +L:     linux-pm@vger.kernel.org
> +L:     linux-samsung-soc@vger.kernel.org
> +S:     Maintained
> +F:     Documentation/devicetree/bindings/devfreq/exynos5-dmc.txt

Maintainers change should go with the next change, I think. It looks
unusual to add an entry for driver... without the driver.

Best regards,
Krzysztof

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