[PATCH 4/5] ARM: S3C24XX: convert boards to use common restart function

[Tomasz Figa]

On 23.01.2014 20:02, Heiko Stübner wrote:
> Am Donnerstag, 23. Januar 2014, 19:51:34 schrieb Tomasz Figa:
>> On 23.01.2014 19:36, Heiko Stübner wrote:
>>> Am Donnerstag, 23. Januar 2014, 19:12:04 schrieb Tomasz Figa:
>>>> Hi Heiko,
>>>>
>>>> On 06.01.2014 19:40, Heiko Stübner wrote:
>>>>> This converts all boards to use the new common restart function instead
>>>>> of SoC specific ones.
>>>>>
>>>>> The mach-s3c2416-dt board now tries to setup either a swrst- or
>>>>> watchdog-
>>>>> reset so that it will be able to handle more s3c24xx-SoCs later on.
>>>>
>>>> [snip]
>>>>
>>>>> diff --git a/arch/arm/mach-s3c24xx/mach-s3c2416-dt.c
>>>>> b/arch/arm/mach-s3c24xx/mach-s3c2416-dt.c index 0a86953..88716fa4 100644
>>>>> --- a/arch/arm/mach-s3c24xx/mach-s3c2416-dt.c
>>>>> +++ b/arch/arm/mach-s3c24xx/mach-s3c2416-dt.c
>>>>> @@ -24,6 +24,7 @@
>>>>>
>>>>>     #include <plat/cpu.h>
>>>>>     #include <plat/pm.h>
>>>>>
>>>>> +#include <plat/watchdog-reset.h>
>>>>>
>>>>>     #include "common.h"
>>>>>
>>>>> @@ -34,6 +35,14 @@ static void __init s3c2416_dt_map_io(void)
>>>>>
>>>>>     static void __init s3c2416_dt_machine_init(void)
>>>>>     {
>>>>>
>>>>> +	s3c24xx_swrst_reset_of_init();
>>>>> +
>>>>> +#ifdef CONFIG_SAMSUNG_WDT_RESET
>>>>> +	/* if no special swrst-device exists try to find a watchdog */
>>>>> +	if (!s3c24xx_swrst_reset_available())
>>>>> +		samsung_wdt_reset_of_init();
>>>>> +#endif
>>>>
>>>> Hmm... I think it would be safe to assume availability of soft reset,
>>>> especially if you could move the restart code to the clock driver.
>>>
>>> ok, so something like the following:
>>>
>>> the boards would simply use samsung_watchdog_reset, which should according
>>> to the manuals be available on all architectures. And the ccf-driver on
>>> appropriate architectures would simple replace the arm_pm_restart
>>> callback with its own SoC specific one?
>>>
>>> For the s3c2412 this also means that the clock-logic would get simplified.
>>>
>>>
>>> Like this, or do I overlook something?
>>
>> Hmm, this would mean a dependency on CONFIG_SAMSUNG_WDT_RESET then. Is
>> there a need to fall back to it on platforms which support soft reset
>> (assuming that CCF driver would always install its restart handler on
>> applicable platforms)?
>
> s3c2410, s3c2440 and s3c2442 do not have the swrst facility. They always use
> samsung_wdt_reset.
>
> In general, I want to try establishing some sort of general restart way, as in
> the future one dt-board should hopefully be enough to cover all s3c24xx soc
> variants.

If you make SAMSUNG_WDT_RESET always selected on S3C24XX then I guess 
it's fine.

>
>
>> Note that you can make the restart field NULL in mach_desc in board files.
>
> As I said above, this is mainly meant for the dt-case. The legacy-board files
> are more or less only secondary, and the affected boards can of course then
> have a NULL restart handle :-) .
>
> So for this the dt-board could simply use the wdt-reset, which then gets
> replaced by the ccf-based reset if appropriate.

OK. By the way, are there any benefits of using this software reset over 
watchdog reset? Maybe all S3C24xx could simply use watchdog reset and no 
special handling of those with swrst would be needed.

Best regards,
Tomasz