[PATCH] ARM: S5PV210: add clocks (struct clk).

[MyungJoo Ham]

Hello, again.

On Fri, Jul 9, 2010 at 11:59 AM, MyungJoo Ham <myungjoo.ham at samsung.com> wrote:
> Hello,
>
> On Fri, Jul 9, 2010 at 11:36 AM, Kukjin Kim <kgene.kim at samsung.com> wrote:
>> MyungJoo Ham wrote:
>>>
>> Hi,
>>
>> Please include Ben Dooks in the Cc..
>> And...excuse me..who is benh at kernel.crashing.org?
>
> Ah.. I was confused by my own reply regarding common struct clk, which
> had benh at kernel.crashing.org as Cc. I'll update the CC setting.
>
>>
>>> Many clocks were not listed in the previous
>>> arch/arm/mach-s5pv210/clock.c
>>>
>>> We have added clocks defined as CLK_GATE_IPx[] in the user manual of
>>> S5PV210. However, the clocks that were not turned on at the boot time
>>> when tested with the previous kernel versions (2.6.32, 2.6.29) are
>>> defined in "init_clocks_disabled" so that they are turned off at the
>>> boot time.
>>
>> I think, no need to register all of clocks which are in the CLK_GATE_IPx
>> into 'init_clocks_disabled'..because it depends on each platform or project.
>>
>>>
>>> The clocks added from CLK_GATE_IPx are:
>>>       CSIS, JPEG, FIMC0 - 2, NFCON, SROMC, TVENC, HDMI, MIXER, VP,
>>>       DSIM, TSI, HOSTIF, MODEM, PCM0 - 2, I2C-HDMI-PHY, I2C-HDMI-DDC,
>>>       AC97, SPDIF, SECKEY, IEM-APC, IEM-IEC, CHIP-ID, PDMA0 - 1,
>>>       MDMA, DMC0 - 1, NANDXL, TZIC0 - 3, VIC0 - 3, SECJTAG, CORESIGHT,
>>>       SDM, SECSS, SYSCON, GPIO, TZPC0 - 3
>>>
>>
>> For example...in the case of JPEG, FIMC, disabling is better at the booting
>> time..because can be enabled dynamically in the device driver when it is
>> used.
>> But if CORESIGHT which does not having own driver is disabled at that time,
>> basically can't use JTAG debugger.
>>
>> So need to sort out clocks to register into 'init_clocks_disabled'
>>
>
> Yes, I agree. I'll put some clocks including CORESIGHT out of
> init_clocks_disabled.
>

Oh.. well, CORESIGHT is not included in init_clocks_disabled in the patch.

In this patch, PDMA, MDMA, DMC, NANDXL, TZIC, VIC, SECJTAG, CORESIGHT,
SDM, SECSS, SYSCON, GPIO, and TZPC are not added to
init_clocks_disabled, but to init_clocks.

Only others including CSIS, JPEG, FIMC0 - 2, NFCON, SROMC, TVENC,
HDMI, MIXER, VP, DSIM, TSI, HOSTIF, MODEM, PCM0 - 2, I2C-HDMI-PHY,
I2C-HDMI-DDC, AC97, SPDIF, SECKEY, IEM-APC, IEM-IEC, and CHIP-ID are
added to init_clocks_disabled. In this list, are there any clocks that
should be out of init_clocks_disabled?

>
> Anyway, I've been considering adding "flag" to struct clk, which has
> the following bits:
>
> #define CLKFLAGS_BOOT_ON        (0x1)
> #define CLKFLAGS_CANNOT_DISABLE (0x2)
> #define CLKFLAGS_ALWAYS_ON      (CLKFLAGS_BOOT_ON | CLKFLAGS_CANNOT_DISABLE)
> #define CLKFLAGS_BOOT_OFF       (0x4) /* Force off when boot */
> #define CLKFLAGS_DEPRECATED     (0x8) /* Warn when clk_get'd */
> /* Note that CLKFLAGS_BOOT_ON and CLKFLAGS_CANNOT_DISABLE overrides
>  * CLKFLAGS_BOOT_OFF */
>
> and merging init_clocks and init_clocks_disabled. This provides more
> precise control on clocks, and we've been using such features in other
> versions of the kernel. Besides, combined with
> powerdomain control, these flags are helpful on implementing
> powerdomain/block-gating control.
>
>
>>> Signed-off-by: MyungJoo Ham <myungjoo.ham at samsung.com>
>>> Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
>>> ---
>>>  arch/arm/mach-s5pv210/clock.c |  298
>>> ++++++++++++++++++++++++++++++++++++++++-
>>>  1 files changed, 297 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/arch/arm/mach-s5pv210/clock.c b/arch/arm/mach-s5pv210/clock.c
>>> index b3d156c..aa2b1c5 100644
>>> --- a/arch/arm/mach-s5pv210/clock.c
>>> +++ b/arch/arm/mach-s5pv210/clock.c
>>
>> (snip)
>>
>> Thanks.
>>
>> Best regards,
>> Kgene.
>> --
>> Kukjin Kim <kgene.kim at samsung.com>, Senior Engineer,
>> SW Solution Development Team, Samsung Electronics Co., Ltd.
>>
>>
>
> Cheers!
> - MyungJoo
>
> --
> MyungJoo Ham (함명주), Ph.D.
> Mobile Software Platform Lab,
> Digital Media and Communications (DMC) Business
> Samsung Electronics
> cell: 82-10-6714-2858
>



-- 
MyungJoo Ham (함명주), Ph.D.
Mobile Software Platform Lab,
Digital Media and Communications (DMC) Business
Samsung Electronics
cell: 82-10-6714-2858