[PATCH v4 05/12] ARM: EXYNOS: add support uart for EXYNOS4 and EXYNOS5

[Marek Szyprowski]

Hello,

On Thursday, March 22, 2012 3:08 PM Kukjin Kim wrote:

> On 03/21/12 03:45, Marek Szyprowski wrote:
> > Hello,
> >
> > On Wednesday, March 21, 2012 10:14 AM Thomas Abraham wrote:
> >
> >> On 14 March 2012 20:12, Kukjin Kim<kgene.kim at samsung.com>  wrote:
> >>> Actually, the base address of uart is different between EXYNOS4
> >>> and EXYNOS5 and this patch enables to support uart for EXYNOS4
> >>> and EXYNOS5 SoCs at runtime.
> >>>
> >>> Signed-off-by: Kukjin Kim<kgene.kim at samsung.com>
> >>> ---
> >>
> >> [...]
> >>
> >>> diff --git a/arch/arm/mach-exynos/include/mach/debug-macro.S b/arch/arm/mach-
> >> exynos/include/mach/debug-macro.S
> >>> index 6cacf16..6c857ff 100644
> >>> --- a/arch/arm/mach-exynos/include/mach/debug-macro.S
> >>> +++ b/arch/arm/mach-exynos/include/mach/debug-macro.S
> >>> @@ -21,8 +21,13 @@
> >>>          */
> >>>
> >>>         .macro addruart, rp, rv, tmp
> >>> -               ldr     \rp, = S3C_PA_UART
> >>> -               ldr     \rv, = S3C_VA_UART
> >>> +               mov     \rp, #0x10000000
> >>
> >> This is physical address of Exynos4/5 CPUID register which cannot be
> >> used here. And virtual address S5P_VA_CPUID also cannot be used here
> >> since this will be called before paging_init when earlyprintk boot
> >> param is used. So, with this change, earlyprintk does not work for
> >> both Exynos4 and Exynos5.
> >
> > I confirm, printascii freeze the system on EXYNOS4 after that patch,
> > tested on Exynos4210 Nuri board.
> >
> Hi,
> 
> I think, it can be solved with following and if no problems, it will be
> fixed during v3.4-rcX.
> 
> diff --git a/arch/arm/mach-exynos/include/mach/debug-macro.S
> b/arch/arm/mach-exynos/in
> index 6c857ff..a865417 100644
> --- a/arch/arm/mach-exynos/include/mach/debug-macro.S
> +++ b/arch/arm/mach-exynos/include/mach/debug-macro.S
> @@ -21,10 +21,10 @@
>           */
> 
>          .macro addruart, rp, rv, tmp
> -               mov     \rp, #0x10000000
> -               ldr     \rp, [\rp, #0x0]
> -               and     \rp, \rp, #0xf00000
> -               teq     \rp, #0x500000          @@ EXYNOS5
> +               mrc     p15, 0, \tmp, c0, c0, 0
> +               and     \tmp, \tmp, #0xf0
> +               teq     \tmp, #0xf0             @@ A15
> +
>                  ldreq   \rp, =EXYNOS5_PA_UART
>                  movne   \rp, #EXYNOS4_PA_UART   @@ EXYNOS4
>                  ldr     \rv, =S3C_VA_UART
> 

The above patch solved the problem on Exynos4.

Tested-by: Marek Szyprowski <m.szyprowski at samsung.com>

Best regards
-- 
Marek Szyprowski
Samsung Poland R&D Center