Messages in this thread Patch in this message | | | Date | Thu, 13 Mar 2014 17:53:08 +0000 | From | Mark Rutland <> | Subject | Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12 |
| |
On Thu, Mar 13, 2014 at 08:17:29AM +0000, Chanwoo Choi wrote: > This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface > 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@samsung.com> > --- > .../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 > +scaling according to PPMU counters of memory controllers > + > +Required properties: > +- compatible : should contain Exynos4 SoC type as follwoing: > + - "samsung,exynos4x12-busfreq" for Exynos4x12 > + - "samsung,exynos4210-busfreq" for Exynos4210 Is there a device called "busfreq"? What device does this binding describe?
> +- reg : offset and length of the ppmudmc0/1 > + - PPMU (Performance Profiling Monitoring Units)
You seem to require a particular order here. It would be good to be explicit about it.
> + : 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.
This is superfluous, and Linux-specific. The binding document shouldn't need to refer to drivers.
> +- clocks : clock number of ppmudmc0/1 > +- clock-names : clock name of ppmudmc0/1
Are these two clocks, or one clock with a slash in the name?
Please list each name separately.
> +- vdd_int-supply: regulator for interface block of Exynos4 > + > +Optional properties: > +- vdd_mif-supply: regulator for DMC block of Exynos4x12 if Exynos4x12 Soc > +- regs-name : register name of ppmudmc0/1
This is completely nonstandard. Did you mean reg-names?
Please be explicit about the names you expect. Write them in full, quoted, and describe the relationship to the reg property.
> + > +All the required listed above must be defined under code busfreq with devfreq
I'm having some difficulty figuring out what exactly this is intended to mean.
Thanks, Mark.
| |