Re: [PATCH v8 09/16] clockevents/drivers: Add STM32 Timer driver

Daniel Lezcano
2015-05-19T09:59:52Z

On 05/19/2015 11:44 AM, Maxime Coquelin wrote:
> 2015-05-19 11:06 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>:
>> On 05/19/2015 10:55 AM, Maxime Coquelin wrote:
>>>
>>> 2015-05-19 10:16 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>:
>>>>
>>>> On 05/18/2015 04:03 PM, Maxime Coquelin wrote:
>>>>>
>>>>>
>>>>> 2015-05-18 15:10 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>:
>>>>>>
>>>>>>
>>>>>> On 05/09/2015 09:53 AM, Maxime Coquelin wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> STM32 MCUs feature 16 and 32 bits general purpose timers with
>>>>>>> prescalers.
>>>>>>> The drivers detects whether the time is 16 or 32 bits, and applies a
>>>>>>> 1024 prescaler value if it is 16 bits.
>>>>>>>
>>>>>>> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
>>>>>>> Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
>>>>>>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
>>>>>>> ---
>>>>>>> drivers/clocksource/Kconfig | 8 ++
>>>>>>> drivers/clocksource/Makefile | 1 +
>>>>>>> drivers/clocksource/timer-stm32.c | 184
>>>>>>> ++++++++++++++++++++++++++++++++++++++
>>>>>>> 3 files changed, 193 insertions(+)
>>>>>>> create mode 100644 drivers/clocksource/timer-stm32.c
>>>>>>>
>>>>>>> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
>>>>>>> index bf9364c..2443520 100644
>>>>>>> --- a/drivers/clocksource/Kconfig
>>>>>>> +++ b/drivers/clocksource/Kconfig
>>>>>>> @@ -106,6 +106,14 @@ config CLKSRC_EFM32
>>>>>>> Support to use the timers of EFM32 SoCs as clock source
>>>>>>> and
>>>>>>> clock
>>>>>>> event device.
>>>>>>>
>>>>>>> +config CLKSRC_STM32
>>>>>>> + bool "Clocksource for STM32 SoCs" if !ARCH_STM32
>>>>>>> + depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST)
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> Are the interactive bool and the 'COMPILE_TEST' necessary ?
>>>>>>
>>>>>
>>>>> The interactive bool is necessary if we want to be able to
>>>>> select/deselect it in COMPILE_TEST configuration.
>>>>> And personnaly, I think COMPILE_TEST use makes sense.
>>>>>
>>>>> Note that other timer drivers are doing the same thing today
>>>>> (CLKSRC_EFM32, SH_TIMER_CMT, EM_TIMER_STI...).
>>>>>
>>>>> Do you have a specific concern regarding COMPILE_TEST?
>>>>
>>>>
>>>>
>>>> Actually, we try to keep the timer selection non-interactive and let the
>>>> platform's Kconfig to select the timer.
>>>
>>>
>>> Ok.
>>>
>>>>
>>>> I like when the code is consistent. The COMPILE_TEST was introduced and
>>>> created a precedence. I would like to get rid of the interactive timer
>>>> selection but I did not have time to go through this yet.
>>>
>>>
>>> Indeed, consistency is important.
>>> On my side, I don't have a strong opinion regarding the COMPILE_TEST
>>> thing.
>>> IMHO, it is more a subsystem's maintainer choice.
>>>
>>> So, if as a maintainer you don't use it and prefer not supporting it,
>>> I'm fine to provide you a new version without COMPILE_TEST.
>>> Doing that, the interactive selection will disappear too.
>>>
>>> I can provide you a new version this evenning.
>>
>>
>> Ok, great.
>
> Is the below Kconfig entry fine for you?
>
> config CLKSRC_STM32
> def_bool y if ARCH_STM32
> select CLKSRC_MMIO

config CLKSRC_STM32
bool
select CLKSRC_MMIO

and in the arch/arm/mach-stm32/Kconfig add select CLKSRC_STM32

> Best regards,
> Maxime
>
>
>>
>> Thanks
>> -- Daniel
>>
>>
>>>>
>>>>
>>>>
>>>> --
>>>> <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
>>>>
>>>> Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
>>>> <http://twitter.com/#!/linaroorg> Twitter |
>>>> <http://www.linaro.org/linaro-blog/> Blog
>>>>
>>
>>
>> --
>> <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
>>
>> Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
>> <http://twitter.com/#!/linaroorg> Twitter |
>> <http://www.linaro.org/linaro-blog/> Blog
>>

--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |