by Pankaj Dubey

[permalink] [raw]

Subject: Re: [PATCH v5 9/9] drivers: soc: Add support for Exynos PMU driver

On Saturday 14 November 2015 05:00 PM, Krzysztof Kozlowski wrote:
> W dniu 14.11.2015 o 00:36, Pankaj Dubey pisze:
>> On 13 November 2015 at 15:58, Krzysztof Kozlowski
>> <[email protected]> wrote:
>>>
>>> On 13.11.2015 18:29, Pankaj Dubey wrote:
>>>> This patch moves Exynos PMU driver implementation from "arm/mach-exynos"
>>>> to "drivers/soc/samsung". This driver is mainly used for setting misc
>>>> bits of register from PMU IP of Exynos SoC which will be required to
>>>> configure before Suspend/Resume. Currently all these settings are done
>>>> in "arch/arm/mach-exynos/pmu.c" but moving ahead for ARM64 based SoC
>>>> support, there is a need of this PMU driver in driver/* folder.
>>>>
>>>> This driver uses existing DT binding information and there should
>>>> be no functionality change in the supported platforms.
>>>>
>>>> Signed-off-by: Amit Daniel Kachhap <[email protected]>
>>>> Signed-off-by: Pankaj Dubey <[email protected]>
>>>> ---
>>>> arch/arm/mach-exynos/Kconfig | 1 +
>>>> arch/arm/mach-exynos/Makefile | 4 +---
>>>> drivers/soc/samsung/Kconfig | 4 ++++
>>>> drivers/soc/samsung/Makefile | 4 ++++
>>>> arch/arm/mach-exynos/pmu.c => drivers/soc/samsung/exynos-pmu.c | 0
>>>> {arch/arm/mach-exynos => drivers/soc/samsung}/exynos-pmu.h | 0
>>>> {arch/arm/mach-exynos => drivers/soc/samsung}/exynos3250-pmu.c | 0
>>>> {arch/arm/mach-exynos => drivers/soc/samsung}/exynos4-pmu.c | 0
>>>> {arch/arm/mach-exynos => drivers/soc/samsung}/exynos5250-pmu.c | 0
>>>> {arch/arm/mach-exynos => drivers/soc/samsung}/exynos5420-pmu.c | 0
>>>> 10 files changed, 10 insertions(+), 3 deletions(-)
>>>> rename arch/arm/mach-exynos/pmu.c => drivers/soc/samsung/exynos-pmu.c (100%)
>>>> rename {arch/arm/mach-exynos => drivers/soc/samsung}/exynos-pmu.h (100%)
>>>> rename {arch/arm/mach-exynos => drivers/soc/samsung}/exynos3250-pmu.c (100%)
>>>> rename {arch/arm/mach-exynos => drivers/soc/samsung}/exynos4-pmu.c (100%)
>>>> rename {arch/arm/mach-exynos => drivers/soc/samsung}/exynos5250-pmu.c (100%)
>>>> rename {arch/arm/mach-exynos => drivers/soc/samsung}/exynos5420-pmu.c (100%)
>>>>
>>>> diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
>>>> index 83c85f5..874cb38 100644
>>>> --- a/arch/arm/mach-exynos/Kconfig
>>>> +++ b/arch/arm/mach-exynos/Kconfig
>>>> @@ -16,6 +16,7 @@ menuconfig ARCH_EXYNOS
>>>> select ARM_GIC
>>>> select COMMON_CLK_SAMSUNG
>>>> select EXYNOS_THERMAL
>>>> + select EXYNOS_PMU
>>>> select EXYNOS_SROM if PM
>>>> select HAVE_ARM_SCU if SMP
>>>> select HAVE_S3C2410_I2C if I2C
>>>> diff --git a/arch/arm/mach-exynos/Makefile b/arch/arm/mach-exynos/Makefile
>>>> index 2d58063..34d29df 100644
>>>> --- a/arch/arm/mach-exynos/Makefile
>>>> +++ b/arch/arm/mach-exynos/Makefile
>>>> @@ -9,9 +9,7 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) += -I$(srctree)/$(src)/include -I$(srctree)
>>>>
>>>> # Core
>>>>
>>>> -obj-$(CONFIG_ARCH_EXYNOS) += exynos.o pmu.o exynos-smc.o firmware.o \
>>>> - exynos3250-pmu.o exynos4-pmu.o \
>>>> - exynos5250-pmu.o exynos5420-pmu.o
>>>> +obj-$(CONFIG_ARCH_EXYNOS) += exynos.o exynos-smc.o firmware.o
>>>>
>>>> obj-$(CONFIG_EXYNOS_CPU_SUSPEND) += pm.o sleep.o
>>>> obj-$(CONFIG_PM_SLEEP) += suspend.o
>>>> diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
>>>> index 2833b5b..f545d6c 100644
>>>> --- a/drivers/soc/samsung/Kconfig
>>>> +++ b/drivers/soc/samsung/Kconfig
>>>> @@ -10,4 +10,8 @@ config EXYNOS_SROM
>>>> bool
>>>> depends on ARM && ARCH_EXYNOS && PM
>>>>
>>>> +config EXYNOS_PMU
>>>> + bool
>>>> + depends on ARCH_EXYNOS
>>>> +
>>>> endmenu
>>>> diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
>>>> index 9c554d5..26fb489 100644
>>>> --- a/drivers/soc/samsung/Makefile
>>>> +++ b/drivers/soc/samsung/Makefile
>>>> @@ -1 +1,5 @@
>>>> obj-$(CONFIG_EXYNOS_SROM) += exynos-srom.o
>>>> +ifdef CONFIG_ARM
>>>> +obj-$(CONFIG_EXYNOS_PMU) += exynos-pmu.o exynos3250-pmu.o exynos4-pmu.o \
>>>> + exynos5250-pmu.o exynos5420-pmu.o
>>>> +endif
>>>
>>> Why ifdef CONFIG_ARM? This already depends on ARCH_EXYNOS. If you want
>>> to limit to ARMv7 then add the dependency to Kconfig (just like
>>> EXYNOS_SROM).
>>>
>>
>> This is required, so that 32-bit based Exynos SoC's PMU should not get
>> compiled when we are compiling for ARM64 and vice-versa.
>>
>> For example: In future, I have plan to add exynos7 PMU support as -
>>
>> ifdef CONFIG_ARM64
>> obj-$(CONFIG_EXYNOS_PMU) += exynos-pmu.o exynos7-pmu.o
>> endif
>>
>> Thus preventing compilation of ARM64 based SoCs PMU data files when we
>> are compiling for ARM.
>>
>> Only exynos-pmu.c will be shared and compiled in both cases.
>
> But this actually spreads Kconfig configuration over different places:
> Kconfig and Makefile. It confuses and makes it more difficult in the
> future to maintain and extend.
>

I could not understand your point here. Will you please explain what
issue you can see in this approach?

> This should be in Kconfig. If you want to limit this per architecture
> (is it really needed?) then maybe define different EXYNOS_PMU config
> symbols?
>

Do you mean we need to have separate configs for enabling PMU on ARM and
ARM64 based Exynos SoCs?

Thanks,
Pankaj Dubey
> Best regards,
> Krzysztof
>
>
>
>
>

2015-11-17 04:28:32

by Krzysztof Kozlowski

[permalink] [raw]

Subject: Re: [PATCH v5 9/9] drivers: soc: Add support for Exynos PMU driver

On 17.11.2015 12:44, pankaj.dubey wrote:
>
>
> On Saturday 14 November 2015 05:00 PM, Krzysztof Kozlowski wrote:
>> W dniu 14.11.2015 o 00:36, Pankaj Dubey pisze:
>>> On 13 November 2015 at 15:58, Krzysztof Kozlowski
>>> <[email protected]> wrote:
>>>>
>>>> On 13.11.2015 18:29, Pankaj Dubey wrote:
>>>>> This patch moves Exynos PMU driver implementation from
>>>>> "arm/mach-exynos"
>>>>> to "drivers/soc/samsung". This driver is mainly used for setting misc
>>>>> bits of register from PMU IP of Exynos SoC which will be required to
>>>>> configure before Suspend/Resume. Currently all these settings are done
>>>>> in "arch/arm/mach-exynos/pmu.c" but moving ahead for ARM64 based SoC
>>>>> support, there is a need of this PMU driver in driver/* folder.
>>>>>
>>>>> This driver uses existing DT binding information and there should
>>>>> be no functionality change in the supported platforms.
>>>>>
>>>>> Signed-off-by: Amit Daniel Kachhap <[email protected]>
>>>>> Signed-off-by: Pankaj Dubey <[email protected]>
>>>>> ---
>>>>> arch/arm/mach-exynos/Kconfig | 1 +
>>>>> arch/arm/mach-exynos/Makefile |
>>>>> 4 +---
>>>>> drivers/soc/samsung/Kconfig |
>>>>> 4 ++++
>>>>> drivers/soc/samsung/Makefile |
>>>>> 4 ++++
>>>>> arch/arm/mach-exynos/pmu.c => drivers/soc/samsung/exynos-pmu.c | 0
>>>>> {arch/arm/mach-exynos => drivers/soc/samsung}/exynos-pmu.h | 0
>>>>> {arch/arm/mach-exynos => drivers/soc/samsung}/exynos3250-pmu.c | 0
>>>>> {arch/arm/mach-exynos => drivers/soc/samsung}/exynos4-pmu.c | 0
>>>>> {arch/arm/mach-exynos => drivers/soc/samsung}/exynos5250-pmu.c | 0
>>>>> {arch/arm/mach-exynos => drivers/soc/samsung}/exynos5420-pmu.c | 0
>>>>> 10 files changed, 10 insertions(+), 3 deletions(-)
>>>>> rename arch/arm/mach-exynos/pmu.c =>
>>>>> drivers/soc/samsung/exynos-pmu.c (100%)
>>>>> rename {arch/arm/mach-exynos => drivers/soc/samsung}/exynos-pmu.h
>>>>> (100%)
>>>>> rename {arch/arm/mach-exynos =>
>>>>> drivers/soc/samsung}/exynos3250-pmu.c (100%)
>>>>> rename {arch/arm/mach-exynos =>
>>>>> drivers/soc/samsung}/exynos4-pmu.c (100%)
>>>>> rename {arch/arm/mach-exynos =>
>>>>> drivers/soc/samsung}/exynos5250-pmu.c (100%)
>>>>> rename {arch/arm/mach-exynos =>
>>>>> drivers/soc/samsung}/exynos5420-pmu.c (100%)
>>>>>
>>>>> diff --git a/arch/arm/mach-exynos/Kconfig
>>>>> b/arch/arm/mach-exynos/Kconfig
>>>>> index 83c85f5..874cb38 100644
>>>>> --- a/arch/arm/mach-exynos/Kconfig
>>>>> +++ b/arch/arm/mach-exynos/Kconfig
>>>>> @@ -16,6 +16,7 @@ menuconfig ARCH_EXYNOS
>>>>> select ARM_GIC
>>>>> select COMMON_CLK_SAMSUNG
>>>>> select EXYNOS_THERMAL
>>>>> + select EXYNOS_PMU
>>>>> select EXYNOS_SROM if PM
>>>>> select HAVE_ARM_SCU if SMP
>>>>> select HAVE_S3C2410_I2C if I2C
>>>>> diff --git a/arch/arm/mach-exynos/Makefile
>>>>> b/arch/arm/mach-exynos/Makefile
>>>>> index 2d58063..34d29df 100644
>>>>> --- a/arch/arm/mach-exynos/Makefile
>>>>> +++ b/arch/arm/mach-exynos/Makefile
>>>>> @@ -9,9 +9,7 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) +=
>>>>> -I$(srctree)/$(src)/include -I$(srctree)
>>>>>
>>>>> # Core
>>>>>
>>>>> -obj-$(CONFIG_ARCH_EXYNOS) += exynos.o pmu.o exynos-smc.o
>>>>> firmware.o \
>>>>> - exynos3250-pmu.o exynos4-pmu.o \
>>>>> - exynos5250-pmu.o
>>>>> exynos5420-pmu.o
>>>>> +obj-$(CONFIG_ARCH_EXYNOS) += exynos.o exynos-smc.o firmware.o
>>>>>
>>>>> obj-$(CONFIG_EXYNOS_CPU_SUSPEND) += pm.o sleep.o
>>>>> obj-$(CONFIG_PM_SLEEP) += suspend.o
>>>>> diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
>>>>> index 2833b5b..f545d6c 100644
>>>>> --- a/drivers/soc/samsung/Kconfig
>>>>> +++ b/drivers/soc/samsung/Kconfig
>>>>> @@ -10,4 +10,8 @@ config EXYNOS_SROM
>>>>> bool
>>>>> depends on ARM && ARCH_EXYNOS && PM
>>>>>
>>>>> +config EXYNOS_PMU
>>>>> + bool
>>>>> + depends on ARCH_EXYNOS
>>>>> +
>>>>> endmenu
>>>>> diff --git a/drivers/soc/samsung/Makefile
>>>>> b/drivers/soc/samsung/Makefile
>>>>> index 9c554d5..26fb489 100644
>>>>> --- a/drivers/soc/samsung/Makefile
>>>>> +++ b/drivers/soc/samsung/Makefile
>>>>> @@ -1 +1,5 @@
>>>>> obj-$(CONFIG_EXYNOS_SROM) += exynos-srom.o
>>>>> +ifdef CONFIG_ARM
>>>>> +obj-$(CONFIG_EXYNOS_PMU) += exynos-pmu.o exynos3250-pmu.o
>>>>> exynos4-pmu.o \
>>>>> + exynos5250-pmu.o
>>>>> exynos5420-pmu.o
>>>>> +endif
>>>>
>>>> Why ifdef CONFIG_ARM? This already depends on ARCH_EXYNOS. If you want
>>>> to limit to ARMv7 then add the dependency to Kconfig (just like
>>>> EXYNOS_SROM).
>>>>
>>>
>>> This is required, so that 32-bit based Exynos SoC's PMU should not get
>>> compiled when we are compiling for ARM64 and vice-versa.
>>>
>>> For example: In future, I have plan to add exynos7 PMU support as -
>>>
>>> ifdef CONFIG_ARM64
>>> obj-$(CONFIG_EXYNOS_PMU) += exynos-pmu.o exynos7-pmu.o
>>> endif
>>>
>>> Thus preventing compilation of ARM64 based SoCs PMU data files when we
>>> are compiling for ARM.
>>>
>>> Only exynos-pmu.c will be shared and compiled in both cases.
>>
>> But this actually spreads Kconfig configuration over different places:
>> Kconfig and Makefile. It confuses and makes it more difficult in the
>> future to maintain and extend.
>>
>
> I could not understand your point here. Will you please explain what
> issue you can see in this approach?

You are spreading Kconfig symbols over different places. These should be
put only in one - in Kconfig.

Some time later someone will add COMPILE_TEST to Kconfig and wonder why
it does not work... oh yeah, because dependency was put not only in
Kconfig but also in Makefile. One place for dependency: Kconfig.

>
>> This should be in Kconfig. If you want to limit this per architecture
>> (is it really needed?) then maybe define different EXYNOS_PMU config
>> symbols?
>>
>
> Do you mean we need to have separate configs for enabling PMU on ARM and
> ARM64 based Exynos SoCs?

Yes. If you want to separate ARMv7 from ARMv8 then yes. Just like we
have for other drivers - usually per SoC but this can be per architecture.

Best regards,
Krzysztof