Messages in this thread | | | Date | Sat, 18 Jul 2020 15:12:41 +0200 | From | Paul Cercueil <> | Subject | Re: [PATCH v6 2/2] clocksource: Ingenic: Add support for the Ingenic X1000 OST. |
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Hi Daniel,
Le ven. 17 juil. 2020 à 10:02, Daniel Lezcano <daniel.lezcano@linaro.org> a écrit : > On 17/07/2020 08:13, Zhou Yanjie wrote: >> Hi Daniel, >> >> 在 2020/7/17 下午12:20, Daniel Lezcano 写道: >>> On 10/07/2020 19:02, 周琰杰 (Zhou Yanjie) wrote: >>>> X1000 and SoCs after X1000 (such as X1500 and X1830) had a >>>> separate >>>> OST, it no longer belongs to TCU. This driver will register both a >>>> clocksource and a sched_clock to the system. >>>> >>>> Tested-by: 周正 (Zhou Zheng) <sernia.zhou@foxmail.com> >>>> Co-developed-by: 漆鹏振 (Qi Pengzhen) <aric.pzqi@ingenic.com> >>>> Signed-off-by: 漆鹏振 (Qi Pengzhen) <aric.pzqi@ingenic.com> >>>> Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com> >>>> Reviewed-by: Paul Cercueil <paul@crapouillou.net> >>>> --- >>>> >>>> Notes: >>>> v1->v2: >>>> Fix compile warnings. >>>> Reported-by: kernel test robot <lkp@intel.com> >>>> v2->v3: >>>> No change. >>>> v3->v4: >>>> 1.Rename "ost" to "sysost" >>>> 1.Remove unrelated changes. >>>> 2.Remove ost_clock_parent enum. >>>> 3.Remove ost->percpu_timer_channel/ost->global_timer_channel. >>>> 4.Set up independent .recalc_rate/.set_rate for percpu/global >>>> timer. >>>> 5.No longer call functions in variable declarations. >>>> v4->v5: >>>> Use "of_io_request_and_map()" instead "of_iomap()". >>>> Suggested-by: Paul Cercueil <paul@crapouillou.net> >>>> v5->v6: >>>> No change. >>>> >>>> drivers/clocksource/Kconfig | 11 + >>>> drivers/clocksource/Makefile | 1 + >>>> drivers/clocksource/ingenic-sysost.c | 539 >>>> +++++++++++++++++++++++++++++++++++ >>>> 3 files changed, 551 insertions(+) >>>> create mode 100644 drivers/clocksource/ingenic-sysost.c >>>> >>>> diff --git a/drivers/clocksource/Kconfig >>>> b/drivers/clocksource/Kconfig >>>> index 91418381fcd4..1bca8b8fb30f 100644 >>>> --- a/drivers/clocksource/Kconfig >>>> +++ b/drivers/clocksource/Kconfig >>>> @@ -696,6 +696,17 @@ config INGENIC_TIMER >>>> help >>>> Support for the timer/counter unit of the Ingenic JZ SoCs. >>>> +config INGENIC_SYSOST >>>> + bool "Clocksource/timer using the SYSOST in Ingenic X SoCs" >>> We usually use silent options and let the platform's Kconfig >>> enable it. >>> We show up the option only when COMPILE_TEST is enabled. >>> >>> Is there a reason to do it differently? >> >> >> Do you mean >> >> bool "Clocksource/timer using the SYSOST in Ingenic X SoCs" >> >> or >> >> default MACH_INGENIC ? > > Both, no default here. > > eg. > > bool "Clocksource/timer using the SYSOST in Ingenic X SoCs" if > COMPILE_TEST > > and > > in arch/mips/Kconfig in the config MACH_INGENIC section : > > ... > select INGENIC_SYSOST > ...
Disagreed. That's not how we do things on MIPS. Selecting MACH_INGENIC means "this kernel will support Ingenic SoCs", but not that it will only support these. Hence the depends on MIPS / default MACH_INGENIC.
As for the select INGENIC_SYSOST, this driver only applies to a few SoCs, I certainly don't want it to be force-enabled. I don't even wait it to be force-enabled on X1000, since it is optional there too.
Cheers, -Paul
> >> This driver has some origins from "INGENIC_TIMER" driver and >> "INGENIC_OST" driver. >> Early Ingenic processors used TCU (timer/counter unit, has 6 or 8 >> generic timer channels) to provide clocksource and clockevent (both >> with >> only 16bit precision). This part of the processor can only use >> "INGENIC_TIMER" driver. >> >> Later processors provide an independent 32bit or 64bit timer channel >> (still under TCU, known as ost channel, this channel can not >> generate >> interrupt) to provid higher precision clocksource. The "INGENIC_OST" >> driver is for this channel. These processors can use "INGENIC_TIMER" >> driver, but using "INGENIC_OST" driver to provide higher precision >> clocksource would be a better choice (clockevent still needs to be >> provided by generic timer channel of TCU, and still 16bit >> precision). >> >> And the recent processors provide a SYSOST components, it is >> independent >> from TCU, including a 64bit timer channel for clocksource and a >> 32bit >> timer channel for clockevent. Although these processors can also use >> "INGENIC_TIMER" driver, but the better choice is completely >> independent >> use of "INGENIC_SYSOST" driver to provide higher precision >> clocksource >> and clockevent. > > Ok, the rating should do the job then. > > Thanks for the explanation. > >> You may have already noticed that this independent SYSOST component >> is >> like an upgraded and streamlined TCU, which only retains one generic >> timer channel that can generate interrupts, upgrade it from 16bit to >> 32bit, and then retain the 64bit ost channel. so the driver code and >> Kconfig code of this patch is largely referenced >> "INGENIC_TIMER" driver and "INGENIC_OST" driver. >> >> Thanks and best regards! >> >>>> + default MACH_INGENIC >>>> + depends on MIPS || COMPILE_TEST >>>> + depends on COMMON_CLK >>>> + select MFD_SYSCON >>>> + select TIMER_OF >>>> + select IRQ_DOMAIN >>>> + help >>>> + Support for the SYSOST of the Ingenic X Series SoCs. >>>> + >>> [ ... ] >>> >>> > > > -- > <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
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