On Thursday, March 13, 2014 05:17:29 PM Chanwoo Choi wrote: > This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface This patch adds DT binding documentation not the driver itself. Same comment for the patch summary line. > and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to PPMU > counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC provides > PPMU counters for DMC(Dynamic Memory Controller) to check memory bus utilization > and then busfreq driver adjusts dynamically the operating frequency/voltage > by using DEVFREQ Subsystem. > > Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx> > --- > .../devicetree/bindings/devfreq/exynos4_bus.txt | 49 ++++++++++++++++++++++ > 1 file changed, 49 insertions(+) > create mode 100644 Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > > diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > new file mode 100644 > index 0000000..2a83fcc > --- /dev/null > +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > @@ -0,0 +1,49 @@ > + > +Exynos4210/4x12 busfreq driver > +----------------------------- > + > +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus frequency/voltage SoC > +scaling according to PPMU counters of memory controllers > + > +Required properties: > +- compatible : should contain Exynos4 SoC type as follwoing: following > + - "samsung,exynos4x12-busfreq" for Exynos4x12 > + - "samsung,exynos4210-busfreq" for Exynos4210 > +- reg : offset and length of the ppmudmc0/1 > + - PPMU (Performance Profiling Monitoring Units) > + : It is to profile performance event of DMC(Dynamic Memory > + Controller) So, exynos4_bus.c can check memory bus utilization > + by using PPMU of Exynos4 SoC. It can be improved by changing ordering, i.e. : PPMU of Exynos4 SoC is used to profile performance event of DMC (Dynamic Memory Controller) so the driver can check memory bus utilization. > +- clocks : clock number of ppmudmc0/1 > +- clock-names : clock name of ppmudmc0/1 > +- vdd_int-supply: regulator for interface block of Exynos4 > + > +Optional properties: > +- vdd_mif-supply: regulator for DMC block of Exynos4x12 if Exynos4x12 Soc if using Exynos4x12 SoC > +- regs-name : register name of ppmudmc0/1 > + > +All the required listed above must be defined under code busfreq with devfreq required properties > +Exmaple: Example: > +For Exynos4210 busfreq, please add a newline here > + busfreq@106A0000 { > + compatible = "samsung,exynos4210-busfreq"; > + reg = <0x106A0000 0x2000>, <0x106B0000 0x2000>; > + regs-name = "PPMU_DMC0", "PPMU_DMC1"; > + clocks = <&clock CLK_PPMUDMC0>, <&clock CLK_PPMUDMC1>; > + clock-names = "ppmudmc0", "ppmudmc1"; > + > + vdd_int-supply = <&buck3_reg>; > + }; > + > +For Exynos4x12 busfreq, ditto > + busfreq@106A0000 { > + compatible = "samsung,exynos4x12-busfreq"; > + reg = <0x106A0000 0x2000>, <0x106B0000 0x2000>; > + regs-name = "PPMU_DMC0", "PPMU_DMC1"; > + clocks = <&clock CLK_PPMUDMC0>, <&clock CLK_PPMUDMC1>; > + clock-names = "ppmudmc0", "ppmudmc1"; > + > + vdd_mif-suppy = <&buck1_reg>; > + vdd_int-supply = <&buck3_reg>; > + }; Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html