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

Kukjin Kim kgene.kim at samsung.com
Sun Jul 11 22:32:22 EDT 2010


MyungJoo Ham wrote:
> 
> Hello, again.
> 
Hi :-)

> 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?
> 
Hmm..SROMC should be in 'init_clocks'...because eg., generally network which connected SROM bank, driver doesn't have clock enable code...
And others, looks ok...but frankly, need to check again ;-)

> >
> > 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.
> >>
> >>


Thanks.

Best regards,
Kgene.
--
Kukjin Kim <kgene.kim at samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.




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