From: cw00.choi@samsung•com (Chanwoo Choi)
To: linux-arm-kernel@lists•infradead.org
Subject: [RESEND PATCH v3] clocksource: exynos_mct: Add the support for Exynos 64bit SoC
Date: Mon, 19 Jan 2015 09:54:19 +0900 [thread overview]
Message-ID: <54BC55BB.7050809@samsung.com> (raw)
In-Reply-To: <54B692FB.7030703@linaro.org>
Dear Daniel and Kukjin,
On 01/15/2015 01:02 AM, Daniel Lezcano wrote:
> On 01/14/2015 04:51 PM, Kukjin Kim wrote:
>> On 01/14/15 14:33, Chanwoo Choi wrote:
>>
>> Hi,
>>
>> + Doug, Olof
>>
>>> This patch adds the support for Exynos 64bit SoC. The delay_timer is only used
>>> for Exynos 32bit SoC.
>>>
>> Yes, the Exynos MCT(Multi-Core Timer) is 64bit timer and it is available
>> on 64bit exynos SoC such as exynos7. But basically ARMv8 architecture is
>> including ARM ARCH timer (ARM Generic Timer) and exynos7 also has
>> implemented it and additionally its access is faster than using memory
>> mapped register called SFR for MCT...so Doug submitted patch to use MCT
>> on 32bit exynos SoCs before.
>>
>> I know using MCT on 64bit exynos is usefulness for Power Management and
>> I need to talk to relevant guys in office again. If anything, I'll let
>> you know.
>
> I will wait for your answer before digging more the patch.
>
> Thanks
> -- Daniel
>
>>> Cc: Daniel Lezcano <daniel.lezcano@linaro•org>
>>> Cc: Thomas Gleixner <tglx@linutronix•de>
>>> Cc: Kukjin Kim <kgene.kim@samsung•com>
>>> Cc: Mark Rutland <mark.rutland@arm•com>
>>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung•com>
>>> ---
>>> This patch set is tested on 64-bit Exynos SoC. I send only this patch from
>>> following patchst[1].
>>> [1] https://lkml.org/lkml/2014/12/2/134
>>>
>>> Changes from v2:
>>> - None
>>> Changes from v1:
>>> - Use CONFIG_ARM instead of CONFIG_ARM64
>>>
>>> drivers/clocksource/Kconfig | 1 -
>>> drivers/clocksource/exynos_mct.c | 4 ++++
>>> 2 files changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
>>> index fc01ec2..be38119 100644
>>> --- a/drivers/clocksource/Kconfig
>>> +++ b/drivers/clocksource/Kconfig
>>> @@ -135,7 +135,6 @@ config CLKSRC_METAG_GENERIC
>>>
>>> config CLKSRC_EXYNOS_MCT
>>> def_bool y if ARCH_EXYNOS
>>> - depends on !ARM64
>>> help
>>> Support for Multi Core Timer controller on Exynos SoCs.
>>>
>>> diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
>>> index 9403061..b840ea1 100644
>>> --- a/drivers/clocksource/exynos_mct.c
>>> +++ b/drivers/clocksource/exynos_mct.c
>>> @@ -223,6 +223,7 @@ static u64 notrace exynos4_read_sched_clock(void)
>>> return exynos4_read_count_32();
>>> }
>>>
>>> +#if defined(CONFIG_ARM)
>>> static struct delay_timer exynos4_delay_timer;
>>>
>>> static cycles_t exynos4_read_current_timer(void)
>>> @@ -231,14 +232,17 @@ static cycles_t exynos4_read_current_timer(void)
>>> "cycles_t needs to move to 32-bit for ARM64 usage");
>>> return exynos4_read_count_32();
>>> }
>>> +#endif
>>>
>>> static void __init exynos4_clocksource_init(void)
>>> {
>>> exynos4_mct_frc_start();
>>>
>>> +#if defined(CONFIG_ARM)
>>> exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer;
>>> exynos4_delay_timer.freq = clk_rate;
>>> register_current_timer_delay(&exynos4_delay_timer);
>>> +#endif
>>>
>>> if (clocksource_register_hz(&mct_frc, clk_rate))
>>> panic("%s: can't register clocksource\n", mct_frc.name);
>
>
Do you have any comment about this patch?
Best Regards,
Chanwoo Choi
next prev parent reply other threads:[~2015-01-19 0:54 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-14 5:33 [RESEND PATCH v3] clocksource: exynos_mct: Add the support for Exynos 64bit SoC Chanwoo Choi
2015-01-14 15:51 ` Kukjin Kim
2015-01-14 16:02 ` Daniel Lezcano
2015-01-14 23:57 ` Chanwoo Choi
2015-01-15 11:29 ` Mark Rutland
2015-01-15 12:46 ` Chanwoo Choi
2015-01-15 12:52 ` Chanwoo Choi
2015-01-15 13:34 ` Mark Rutland
2015-01-16 0:03 ` Chanwoo Choi
2015-01-19 0:54 ` Chanwoo Choi [this message]
2015-01-19 9:27 ` Daniel Lezcano
2015-01-19 10:24 ` Chanwoo Choi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=54BC55BB.7050809@samsung.com \
--to=cw00.choi@samsung$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox