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

From: [email-masked] (Kukjin Kim)
Date: Thu, 22 Mar 2012 07:08:22 -0700

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<[email-masked]>  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<[email-masked]>
>>> ---
>>
>> [...]
>>
>>> 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

Thanks.

Best regards,
Kgene.
--
Kukjin Kim <[email-masked]>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.