Re: [Qemu-devel] [PATCH v5 1/4] i.MX: Fix i.MX31 default/reset configuration.

[Peter Crosthwaite]

On Tue, Dec 1, 2015 at 12:25 PM, Jean-Christophe Dubois
<address@hidden> wrote:
> Linux on i.MX31/KZM is expecting the CCM to use the CKIH ref clock instead
> of the CKIL plus the FPM multiplier.
>
> We change the CCMR reg reset value to match linux expected config.
>
> This allow the CCM to provide a 39MHz clk (as expected by linux) instead of
> the actual 50MHz.
>
> With this change the "sleep 60" command on linux is time accurate with
> "real world time".
>
> Signed-off-by: Jean-Christophe Dubois <address@hidden>
> ---
>
> Changes since v1:
>  * Not present
>
> Changes since v2:
>  * Not present
>
> Changes since v3:
>  * Not present
>
> Changes since v4:
>  * Not present
>
>  hw/misc/imx_ccm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/misc/imx_ccm.c b/hw/misc/imx_ccm.c
> index 4cc2bbc..500dda5 100644
> --- a/hw/misc/imx_ccm.c
> +++ b/hw/misc/imx_ccm.c
> @@ -123,7 +123,7 @@ static void imx_ccm_reset(DeviceState *dev)
>  {
>      IMXCCMState *s = IMX_CCM(dev);
>
> -    s->ccmr = 0x074b0b7b;
> +    s->ccmr = 0x074b0b7d;

So a few PDFs later it looks like this is actually user configurable
via a jumper on the KZM board (JP10). I'm tempted to say that Linux's
expectations is a good for the default value, so this change looks
good to me.

Reviewed-by: Peter Crosthwaite <address@hidden>

>      s->pdr0 = 0xff870b48;
>      s->pdr1 = 0x49fcfe7f;
>      s->mpctl = PLL_PD(1) | PLL_MFD(0) | PLL_MFI(6) | PLL_MFN(0);
> --
> 2.5.0
>