Re: [PATCH 2/2] PM / devfreq: exynos-ppmu: Update documentation to support PPMUv2

Krzysztof Kozlowski
2015-07-23T07:58:28Z

On 23.07.2015 16:48, Chanwoo Choi wrote:
> On 07/23/2015 04:37 PM, Krzysztof Kozlowski wrote:
>> On 23.07.2015 10:57, Chanwoo Choi wrote:
>>> This patch updates the documentation to include the information of PPMUv2.
>>> The PPMUv2 is used for Exynos5433 and Exynos7420 to monitor the performance
>>> of each IP in Exynos SoC.
>>>
>>> Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
>>> Cc: Kyungmin Park <kyungmin.park@samsung.com>
>>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
>>> ---
>>> .../bindings/devfreq/event/exynos-ppmu.txt | 42 ++++++++++++++++++++--
>>> 1 file changed, 40 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt b/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt
>>> index b54bf3a2ff57..e8fa6b6a1827 100644
>>> --- a/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt
>>> +++ b/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt
>>> @@ -11,7 +11,7 @@ to various devfreq devices. The devfreq devices would use the event data when
>>> derterming the current state of each IP.
>>>
>>> Required properties:
>>> -- compatible: Should be "samsung,exynos-ppmu".
>>> +- compatible: Should be "samsung,exynos-ppmu" or "samsung,exynos-ppmu-v2.
>>
>> I have doubts about "-v2" suffix. Why not using SoCs compatible suffix?
>> Is it related to ARM Performance Monitoring Unit v2 or maybe Samsung
>> just labelled it v2 for marketing purposes?
>
> As I knew, the version of PPMU was decided by SoC designer without any dependency.
>
> If we prefer to use the SoC name instead of '-v2' version on compatible name,
> we can change them as following:
> - samsung,exynos-ppmu -> samsung,exynos4210-ppmu
> (because Exynos4210 used the PPMU v1 for the first time)
> - samsung,exynos-ppmu-v2 -> samsung,exynos5433-ppmu
> (because Exynos5433 used the PPMU v2 for the first time)

Does the Exynos5433 datasheet mention the "version 2"? I could not find
such annotation in mine.

Krzysztof

>
> Best Regards,
> Chanwoo Choi
>
>>
>> Best regards,
>> Krzysztof
>>
>>> - reg: physical base address of each PPMU and length of memory mapped region.
>>>
>>> Optional properties:
>>> @@ -19,7 +19,7 @@ Optional properties:
>>> - clocks : phandles for clock specified in "clock-names" property
>>> - #clock-cells: should be 1.
>>>
>>> -Example1 : PPMU nodes in exynos3250.dtsi are listed below.
>>> +Example1 : PPMUv1 nodes in exynos3250.dtsi are listed below.
>>>
>>> ppmu_dmc0: ppmu_dmc0@106a0000 {
>>> compatible = "samsung,exynos-ppmu";
>>> @@ -108,3 +108,41 @@ Example2 : Events of each PPMU node in exynos3250-rinato.dts are listed below.
>>> };
>>> };
>>> };
>>> +
>>> +Example3 : PPMUv2 nodes in exynos5433.dtsi are listed below.
>>> +
>>> + ppmu_d0_cpu: ppmu_d0_cpu@10480000 {
>>> + compatible = "samsung,exynos-ppmu-v2";
>>> + reg = <0x10480000 0x2000>;
>>> + status = "disabled";
>>> + };
>>> +
>>> + ppmu_d0_general: ppmu_d0_general@10490000 {
>>> + compatible = "samsung,exynos-ppmu-v2";
>>> + reg = <0x10490000 0x2000>;
>>> + status = "disabled";
>>> + };
>>> +
>>> + ppmu_d0_rt: ppmu_d0_rt@104a0000 {
>>> + compatible = "samsung,exynos-ppmu-v2";
>>> + reg = <0x104a0000 0x2000>;
>>> + status = "disabled";
>>> + };
>>> +
>>> + ppmu_d1_cpu: ppmu_d1_cpu@104b0000 {
>>> + compatible = "samsung,exynos-ppmu-v2";
>>> + reg = <0x104b0000 0x2000>;
>>> + status = "disabled";
>>> + };
>>> +
>>> + ppmu_d1_general: ppmu_d1_general@104c0000 {
>>> + compatible = "samsung,exynos-ppmu-v2";
>>> + reg = <0x104c0000 0x2000>;
>>> + status = "disabled";
>>> + };
>>> +
>>> + ppmu_d1_rt: ppmu_d1_rt@104d0000 {
>>> + compatible = "samsung,exynos-ppmu-v2";
>>> + reg = <0x104d0000 0x2000>;
>>> + status = "disabled";
>>> + };
>>>
>>
>>
>
>