[PATCH] i.MX25 GPT clock fix: ensure correct the clock source

From: s.hauer@pengutronix.de (Sascha Hauer)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] i.MX25 GPT clock fix: ensure correct the clock source
Date: Mon, 1 Aug 2011 12:19:12 +0200	[thread overview]
Message-ID: <20110801101912.GI31404@pengutronix.de> (raw)
In-Reply-To: <3F263ABB4EDE344D974E1983B56807734FFAB7A9@EX-DAG02.eckelmann.group>

On Mon, Aug 01, 2011 at 08:02:07AM +0000, Mehnert, Torsten wrote:
> Request for comment and commit.
> 
> 
> From: T. Mehnert <t.mehnert@eckelmann.de>
> Date: Mon, 4 Jul 2011 15:53:30 +0200
> Subject: [PATCH] i.MX25 GPT clock fix: ensure correct the clock source
> 
> This patch ensures, that Linux will take the correct clock source (AHB_DIV)
> for gpt in the ARM i.MX25 implementation. The currect code depends on the reset
> defaults of the CCM_MCR register. So on some boards it could happen that the
> UPLL is used for clock source, which results in faulty time behavior in Linux.
> In this case all delays or sleeps will will be faktor 1.8 too long.
> 
> Signed-off-by: Torsten Mehnert <t.mehnert@eckelmann.de>

Your mailer converts tabs to spaces, so this patch does not apply.
Fixed this manually this time, but please resolve this issue for
next time.

Sascha

> ---
>  arch/arm/mach-imx/clock-imx25.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/mach-imx/clock-imx25.c b/arch/arm/mach-imx/clock-imx25.c
> index a65838f..bf1ecda 100644
> --- a/arch/arm/mach-imx/clock-imx25.c
> +++ b/arch/arm/mach-imx/clock-imx25.c
> @@ -328,6 +328,10 @@ int __init mx25_clocks_init(void)
>         __raw_writel(__raw_readl(CRM_BASE+0x64) | (1 << 7) | (1 << 0),
>                         CRM_BASE + 0x64);
> 
> +       /* Clock source for gpt is ahb_div */
> +       __raw_writel(__raw_readl(CRM_BASE+0x64) & ~(1 << 5),
> +                       CRM_BASE + 0x64);
> +
>         mxc_timer_init(&gpt_clk, MX25_IO_ADDRESS(MX25_GPT1_BASE_ADDR), 54);
> 
>         return 0;
> --
> 1.7.0.4
> 
> best regards,
>         Torsten
> 
> Torsten Mehnert
> K?lte- und Geb?udeleittechnik (KGL)
> 
> ECKELMANN AG
> Berliner Stra?e 161
> D - 65205 Wiesbaden
> 
> Phone:  +49 (0) 611 / 7103 - 370
> Fax:    +49 (0) 611 / 7103 - 133
> 
> e-Mail: mailto:t.mehnert at eckelmann.de
> Web:    http://www.eckelmann.de
> 
> ECKELMANN AG
> Vorstand: Dr.-Ing. Gerd Eckelmann (Vorsitzender), Dr.-Ing. Peter Cordes, Dr.-Ing. Frank-Thomas Mellert
> Vorsitzender des Aufsichtsrats: Hubertus G. Krossa
> Sitz der Gesellschaft: Wiesbaden
> Amtsgericht Wiesbaden, HRB 12636
> 

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