Re: [PATCH v3 3/4] Documentation: devicetree: add PPMU events description

From: Lukasz Luba
Date: Tue Apr 30 2019 - 17:23:56 EST




On 4/30/19 8:16 AM, Chanwoo Choi wrote:
> Hi Lukasz,
>
> On 19. 4. 19. ìí 10:48, Lukasz Luba wrote:
>> Extend the documenation by events description with new 'event-data-type'
>> field. Add example how the event might be defined in DT.
>>
>> Signed-off-by: Lukasz Luba <l.luba@xxxxxxxxxxxxxxxxxxx>
>> ---
>> .../devicetree/bindings/devfreq/event/exynos-ppmu.txt | 18 ++++++++++++++++++
>> 1 file changed, 18 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt b/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt
>> index 3e36c1d..47feb5f 100644
>> --- a/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt
>> +++ b/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt
>> @@ -145,3 +145,21 @@ Example3 : PPMUv2 nodes in exynos5433.dtsi are listed below.
>> reg = <0x104d0000 0x2000>;
>> status = "disabled";
>> };
>> +
>> +The 'event' type specified in the PPMU node defines 'event-name'
>> +which also contains 'id' number and optionally 'event-data-type'.
>> +
>> +Example:
>> +
>> + events {
>> + ppmu_leftbus_0: ppmu-event0-leftbus {
>> + event-name = "ppmu-event0-leftbus";
>> + event-data-type = <PPMU_RO_DATA_CNT>;
>> + };
>> + };
>> +
>> +The 'event-data-type' defines the type of data which shell be counted
>> +by the counter. You can check include/dt-bindings/pmu/exynos_ppmu.h for
>> +all possible type, i.e. count read requests, count write data in bytes,
>> +etc. This field is optional and when it is missing, the driver code will
>> +use default data type.
>>
>
> How about editing it as following?
>
> --- a/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt
> +++ b/Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt
> @@ -10,14 +10,23 @@ The Exynos PPMU driver uses the devfreq-event class to provide event data
> to various devfreq devices. The devfreq devices would use the event data when
> derterming the current state of each IP.
>
> -Required properties:
> +Required properties for PPMU device:
> - compatible: Should be "samsung,exynos-ppmu" or "samsung,exynos-ppmu-v2.
> - reg: physical base address of each PPMU and length of memory mapped region.
>
> -Optional properties:
> +Optional properties for PPMU device:
> - clock-names : the name of clock used by the PPMU, "ppmu"
> - clocks : phandles for clock specified in "clock-names" property
>
> +Required properties for 'events' child node of PPMU device:
> +- event-name : the unique event name among PPMU device
> +Optional properties for 'events' child node of PPMU device:
> +- event-data-type : Define the type of data which shell be counted
> +by the counter. You can check include/dt-bindings/pmu/exynos_ppmu.h for
> +all possible type, i.e. count read requests, count write data in bytes,
> +etc. This field is optional and when it is missing, the driver code
> +will use default data type.
> +
> Example1 : PPMUv1 nodes in exynos3250.dtsi are listed below.
>
> ppmu_dmc0: ppmu_dmc0@106a0000 {
> @@ -145,3 +154,16 @@ Example3 : PPMUv2 nodes in exynos5433.dtsi are listed below.
> reg = <0x104d0000 0x2000>;
> status = "disabled";
> };
> +
> +Example4 : 'event-data-type' in exynos4412-ppmu-common.dtsi are listed below.
> +
> + &ppmu_dmc0 {
> + status = "okay";
> + events {
> + ppmu_dmc0_3: ppmu-event3-dmc0 {
> + event-name = "ppmu-event3-dmc0";
> + event-data-type = <(PPMU_RO_DATA_CNT |
> + PPMU_WO_DATA_CNT)>;
> + };
> + };
> + };
>
> I agree. It will be changed in the next version.

Regards,
Lukasz