Re: [PATCH 1/3] ARM: dts: Add PMU reg node to exynos4210

[Vikas Sajjan]

Hi Pankaj,

On Thu, Apr 24, 2014 at 6:27 PM, Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx> wrote:
> Hi Vikas,
>
>
> On 04/24/2014 08:59 PM, Vikas Sajjan wrote:
>>
>> +Tomasz
>>
>>
>> On Wed, Apr 2, 2014 at 1:32 PM, Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
>> wrote:
>>>
>>> This patch adds pmu regnode to exynos4210 dtsi to handle
>>> PMU register access via DT.
>>>
>>> Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
>>> ---
>>>   arch/arm/boot/dts/exynos4210.dtsi |    5 +++++
>>>   1 file changed, 5 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/exynos4210.dtsi
>>> b/arch/arm/boot/dts/exynos4210.dtsi
>>> index cacf614..0a2c0fe 100644
>>> --- a/arch/arm/boot/dts/exynos4210.dtsi
>>> +++ b/arch/arm/boot/dts/exynos4210.dtsi
>>> @@ -81,6 +81,11 @@
>>>                  interrupts = <2 2>, <3 2>;
>>>          };
>>>
>>> +       pmu_system_controller: system-controller@10020000 {
>>> +               compatible = "samsung,exynos4210-pmu", "syscon";
>>> +               reg = <0x10020000 0x5000>;
>>
>> Can we have 2 strings as "compatible" and these 2 strings are used by
>> 2 different driver?
>>
>> Because once syscon driver gets probed, exynos-pmu.c [1] driver will
>> never be probed.
>>
>> The new PMU driver [1] completely relies on this. With just
>> exynos_defconfig, you will not notice this issue, since syscon is NOT
>> enabled by exynos_defconfig. When I enabled "System Controller
>> Register R/W Based on Regmap" in menuconfig, I could see PMU driver
>> [1] is NEVER probed.
>>
>> Let me know, if I am missing something.
>>
>>   [1] http://www.spinics.net/lists/arm-kernel/msg319750.html
>
>
> You are correct. We also missed this because "SYSCON" option was
> not enabled in exynos_defconfig.
> I noticed this during preparation of V2 when I planned to use
> "early_syscon_init" [1] as suggested by Sylwester here [2].
>
OK.

> In V2 I will take care of this. I hope soon I will be able to post second

So in your V2, will you be adding new DT node altogether for PMU?
Because with existing DT node "pmu_system_controller"  (which is
already present in mailine for exynos 5250) and SYSCON driver enable,
exynos PMU driver will NEVER probed.

> version of this series, just waiting for testing and internal code review.
>
> [1] https://lkml.org/lkml/2014/4/8/239
> [2] https://lkml.org/lkml/2014/4/2/171
>
>>
>>
>>> +       };
>>> +
>>>          pinctrl_0: pinctrl@11400000 {
>>>                  compatible = "samsung,exynos4210-pinctrl";
>>>                  reg = <0x11400000 0x1000>;
>>> --
>>> 1.7.10.4
>>>
>>>
>>> _______________________________________________
>>> linux-arm-kernel mailing list
>>> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
>>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
>
>
> --
> Best Regards,
> Pankaj Dubey
>
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