[PATCH RFC/RFT] ARM: S5P: Fix USB and 48M clock enable procedure

[Paulius Zaleckas]

On Thu, Oct 14, 2010 at 12:03 PM, Kukjin Kim <kgene.kim at samsung.com> wrote:
> Paulius Zaleckas wrote:
>>
>> Signed-off-by: Paulius Zaleckas <paulius.zaleckas at gmail.com>
>> ---
>>
>>  arch/arm/mach-s5p6440/clock.c              |   23 -------
>>  arch/arm/plat-s5p/clock.c                  |   86
>> ++++++++++++++++++++++++++++
>>  arch/arm/plat-s5p/include/plat/s5p-clock.h |    1
>>  3 files changed, 86 insertions(+), 24 deletions(-)
>>
> Hi Paulius,
>
> There are some comments about your patches which includes previous S3C64XX patches.
>
> Basically your approach looks good trial and structure...but I'm not sure whether your approach can be used commonly on Samsung's all SoCs or not.
> Need to do more test on boards and I already informed your patches to USB engineers in my team, actually need to discuss about this.
>
> As a note, I know, 'xusbxti' clock is structure for external xtal which is used for generating USB clock on board... it depends on board condition, because can be used 12/24/48Mhz on board. The clk_48m means generated actual USB clock, 48Mhz. So should be implemented enable function by using clk_48m...

I don't agree that enable should be for clk_48m. The reason is that
IMO it is possible
to enable 48m clock, but suspend the clock for USB device part (I am
not sure about this yet...).

If that is true than I think we will need one more clk for USB device:

        /->clk_48m
xusbxti-|
        \->clk_usb_device

> Anyway let you know about the result of internal discussion soon, then let's talk.
>
> Thanks.
>
> Best regards,
> Kgene.
> --
> Kukjin Kim <kgene.kim at samsung.com>, Senior Engineer,
> SW Solution Development Team, Samsung Electronics Co., Ltd.