From: shawn.guo@freescale.com (Shawn Guo)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] ARM: vf610: Use ARM Global Timer as clocksource
Date: Thu, 25 Sep 2014 15:50:15 +0800 [thread overview]
Message-ID: <20140925075013.GD6405@dragon> (raw)
In-Reply-To: <1410437175-6636-2-git-send-email-stefan@agner.ch>
On Thu, Sep 11, 2014 at 02:06:15PM +0200, Stefan Agner wrote:
> Use ARM Global Timer as clocksource instead of the PIT timer. This
> leaves the PIT timer for other users e.g. the secondary Cortex-M4
> core. Also, the Global Timer has double the precission (running at
> pheripheral clock compared to IPG clock) and a 64-bit incrementing
> counter register.
I just think of one thing. Will this change cause a problem of the low
power idle support in case we want to power down ARM core in there?
Shawn
>
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> ---
> Theoretically we could remove the PIT driver now. But we could also
> enable both drivers, but is having two clock source useful for the
> Kernel at all?
>
> arch/arm/mach-imx/Kconfig | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
> index 64161aa..adc77180 100644
> --- a/arch/arm/mach-imx/Kconfig
> +++ b/arch/arm/mach-imx/Kconfig
> @@ -656,7 +656,8 @@ config SOC_VF610
> bool "Vybrid Family VF610 support"
> select ARM_GIC
> select PINCTRL_VF610
> - select VF_PIT_TIMER
> + select ARM_GLOBAL_TIMER
> + select CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
> select PL310_ERRATA_769419 if CACHE_L2X0
>
> help
> --
> 2.1.0
>
WARNING: multiple messages have this Message-ID (diff)
From: Shawn Guo <shawn.guo@freescale.com>
To: Stefan Agner <stefan@agner.ch>
Cc: <kernel@pengutronix.de>, <festevam@gmail.com>,
<jingchang.lu@freescale.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] ARM: vf610: Use ARM Global Timer as clocksource
Date: Thu, 25 Sep 2014 15:50:15 +0800 [thread overview]
Message-ID: <20140925075013.GD6405@dragon> (raw)
In-Reply-To: <1410437175-6636-2-git-send-email-stefan@agner.ch>
On Thu, Sep 11, 2014 at 02:06:15PM +0200, Stefan Agner wrote:
> Use ARM Global Timer as clocksource instead of the PIT timer. This
> leaves the PIT timer for other users e.g. the secondary Cortex-M4
> core. Also, the Global Timer has double the precission (running at
> pheripheral clock compared to IPG clock) and a 64-bit incrementing
> counter register.
I just think of one thing. Will this change cause a problem of the low
power idle support in case we want to power down ARM core in there?
Shawn
>
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> ---
> Theoretically we could remove the PIT driver now. But we could also
> enable both drivers, but is having two clock source useful for the
> Kernel at all?
>
> arch/arm/mach-imx/Kconfig | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
> index 64161aa..adc77180 100644
> --- a/arch/arm/mach-imx/Kconfig
> +++ b/arch/arm/mach-imx/Kconfig
> @@ -656,7 +656,8 @@ config SOC_VF610
> bool "Vybrid Family VF610 support"
> select ARM_GIC
> select PINCTRL_VF610
> - select VF_PIT_TIMER
> + select ARM_GLOBAL_TIMER
> + select CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
> select PL310_ERRATA_769419 if CACHE_L2X0
>
> help
> --
> 2.1.0
>
next prev parent reply other threads:[~2014-09-25 7:50 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-11 12:06 [PATCH 1/2] ARM: dts: vf610: Add ARM Global Timer Stefan Agner
2014-09-11 12:06 ` Stefan Agner
2014-09-11 12:06 ` [PATCH 2/2] ARM: vf610: Use ARM Global Timer as clocksource Stefan Agner
2014-09-11 12:06 ` Stefan Agner
2014-09-25 7:50 ` Shawn Guo [this message]
2014-09-25 7:50 ` Shawn Guo
2014-09-25 8:25 ` Stefan Agner
2014-09-25 8:25 ` Stefan Agner
2014-09-25 15:10 ` Shawn Guo
2014-09-25 15:10 ` Shawn Guo
2014-09-25 22:12 ` Bill Pringlemeir
2014-09-26 0:48 ` Shawn Guo
2014-09-12 7:59 ` [PATCH 1/2] ARM: dts: vf610: Add ARM Global Timer Shawn Guo
2014-09-12 7:59 ` Shawn Guo
2014-09-19 14:32 ` Stefan Agner
2014-09-19 14:32 ` Stefan Agner
2014-09-23 15:54 ` Bill Pringlemeir
2014-09-24 7:55 ` Stefan Agner
2014-09-24 15:26 ` Bill Pringlemeir
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