Cc: Rob, devicetree ML
On 29.05.2020 18:31, Sylwester Nawrocki wrote:
> Add documentation for new optional properties in the exynos bus nodes:
> samsung,interconnect-parent, #interconnect-cells.
> These properties allow to specify the SoC interconnect structure which
> then allows the interconnect consumer devices to request specific
> bandwidth requirements.
>
> Signed-off-by: Artur Świgoń <a.swigon@xxxxxxxxxxx>
> Signed-off-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
> ---
> Changes for v5:
> - exynos,interconnect-parent-node renamed to samsung,interconnect-parent
> ---
> Documentation/devicetree/bindings/devfreq/exynos-bus.txt | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/devfreq/exynos-bus.txt b/Documentation/devicetree/bindings/devfreq/exynos-bus.txt
> index e71f752..e0d2daa 100644
> --- a/Documentation/devicetree/bindings/devfreq/exynos-bus.txt
> +++ b/Documentation/devicetree/bindings/devfreq/exynos-bus.txt
> @@ -51,6 +51,11 @@ Optional properties only for parent bus device:
> - exynos,saturation-ratio: the percentage value which is used to calibrate
> the performance count against total cycle count.
>
> +Optional properties for interconnect functionality (QoS frequency constraints):
> +- samsung,interconnect-parent: phandle to the parent interconnect node; for
> + passive devices should point to same node as the exynos,parent-bus property.
> +- #interconnect-cells: should be 0
> +
> Detailed correlation between sub-blocks and power line according to Exynos SoC:
> - In case of Exynos3250, there are two power line as following:
> VDD_MIF |--- DMC
> @@ -185,8 +190,9 @@ Example1:
> ----------------------------------------------------------
>
> Example2 :
> - The bus of DMC (Dynamic Memory Controller) block in exynos3250.dtsi
> - is listed below:
> + The bus of DMC (Dynamic Memory Controller) block in exynos3250.dtsi is
> + listed below. An interconnect path "bus_lcd0 -- bus_leftbus -- bus_dmc"
> + is defined for demonstration purposes.
>
> bus_dmc: bus_dmc {
> compatible = "samsung,exynos-bus";
> @@ -376,12 +382,15 @@ Example2 :
> &bus_dmc {
> devfreq-events = <&ppmu_dmc0_3>, <&ppmu_dmc1_3>;
> vdd-supply = <&buck1_reg>; /* VDD_MIF */
> + #interconnect-cells = <0>;
> status = "okay";
> };
>
> &bus_leftbus {
> devfreq-events = <&ppmu_leftbus_3>, <&ppmu_rightbus_3>;
> vdd-supply = <&buck3_reg>;
> + samsung,interconnect-parent = <&bus_dmc>;
> + #interconnect-cells = <0>;
> status = "okay";
> };
>
> @@ -392,6 +401,8 @@ Example2 :
>
> &bus_lcd0 {
> devfreq = <&bus_leftbus>;
> + samsung,interconnect-parent = <&bus_leftbus>;
> + #interconnect-cells = <0>;
> status = "okay";
> };
>
> --
> 2.7.4
